Skip header and go to main content

Classification Resources
 

 [Search a list of Patent Appplications for class 708]   CLASS 708,ELECTRICAL COMPUTERS: ARITHMETIC PROCESSING AND CALCULATING
Click here for a printable version of this file

SECTION I - CLASS DEFINITION

GENERAL STATEMENT OF THE CLASS SUBJECT MATTER

This is the generic class for electrical apparatus and corresponding methods for performing calculation operations.

SCOPE OF THE CLASS

(1) Note. This class is limited to electrical and calculating computer apparatus and corresponding methods wherein a calculation operation is performed on information carried by wave propagation (either electromagnetic or compressional waves) provided that input to and output from the apparatus is electrical. Note: where the apparatus performing the calculation operation is electrically responsive but the data is not presented to and output from the apparatus as electrical signals, classification is with the appropriate wave energy subject matter, as per one of the optical classes.
(2) Note. Significantly claimed apparatus external to this class, claimed in combination with apparatus under the class definition, which perform data processing or calculation operations are classified in the class appropriate to the external device unless specifically excluded therefrom.
(3) Note. Nominally claimed apparatus external to this class in combination with apparatus under the class definition is classified in this class unless provided for in the appropriate external class.

THIS CLASS IS STRUCTURED INTO THREE MAIN DIVISIONS:

A. Electrical Hybrid Calculating Computers

B. Electrical Digital Calculating Computers

C. Electrical Analog Calculating Computers

SECTION II - REFERENCES TO OTHER CLASSES

SEE OR SEARCH CLASS:

235, Registers,   various subclasses for basic machines and associated indicating mechanisms for ascertaining the number of movements of various devices and machines, plus machines made from these basic machines alone (e.g., cash registers, voting machines)or in combination with various perfecting features, such as printers and recording means, as well as for various data bearing record controlled systems.
307, Electrical Transmission or Interconnection Systems,   various subclasses for generic residual electrical transmission or interconnection systems and miscellaneous circuits.
326, Electronic Digital Logic Circuitry,   various subclasses for digital logic devices.
327, Miscellaneous Active Electrical Nonlinear Devices, Circuit, and Systems,   various subclasses for miscellaneous active device analog circuits.
340, Communications: Electrical,   various subclasses for residual electrical communication systems.
341, Coded Data Generation or Conversion,   various subclasses for electrical pulse and digital code converters.
345, Computer Graphics Processing and Selective Visual Display Systems,   various subclasses for the selective control of two or more light generating or light controlling display elements in accordance with a received image signal.
358, Facsimile and Static Presentation Processing,   subclasses 1.1 through 1.18for static presentation processing (e.g., processing data for printer, etc.).
359, Optics: Systems and Elements,   subclasses 107+ for optical computing without diffraction and subclasses 237+ for optical modulators.
360, Dynamic Magnetic Information Storage or Retrieval,   appropriate subclasses for record carriers and systems wherein information is stored and retrieved by interaction with a medium and there is relative motion between a medium and a transducer, for example, magnetic disk drive devices and control thereof, per se.
361, Electricity: Electrical Systems and Devices,   subclasses 679.08 through 679.2for computer related housing or mounting assemblies with keyboard support.
365, Static Information Storage and Retrieval,   various subclasses for addressable static singular storage elements or plural singular storage elements of the same type.
369, Dynamic Information Storage or Retrieval,   various subclasses for record carriers and systems wherein information is stored and retrieved by interaction with a medium and there is relative motion between a medium and a transducer.
370, Multiplex Communications,   various subclasses for generic multiplexing and demultiplexing systems.
375, Pulse or Digital Communications,   various subclasses for generic pulse or digital communication systems.
377, Electrical Pulse Counters, Pulse Dividers, or Shift Registers: Circuits and Systems,   various subclasses for generic circuits for pulse counting.
379, Telephonic Communications,   various subclasses for two-way electrical communication of intelligible audio information of arbitrary content over a link including an electrical conductor.
382, Image Analysis,   appropriate subclasses for operations performed on image data with the aim of measuring a characteristic of an image, detecting variations, detecting structures, or transforming the image data, and for procedures for analyzing and categorizing patterns present in image data.
700, Data Processing: Generic Control Systems or Specific Applications,   subclasses 1 through 89for generic data processing control systems and subclasses 90-306 for particular application of electrical computers and data processing systems, particularly subclasses 245-264 for data processing of robot control systems.
701, Data Processing: Vehicles, Navigation, and Relative Location,   appropriate subclasses for vehicular or navigational data processing.
702, Data Processing: Measuring, Calibrating, or Testing,   appropriate subclasses for measuring or testing data processing.
703, Data Processing: Structural Design, Modeling, Simulation, and Emulation,   appropriate subclasses.
704, Data Processing: Speech Signal Processing, Linguistics, Language Translation, and Audio Compression/Decompression,   for speech, language or audio compression/decompression processing.
705, Data Processing: Financial, Business Practice, Management, or Cost/Price Determination,   appropriate subclasses for data processing related to business, finances, management, or cost/price determining.
706, Data Processing: Artificial Intelligence,   appropriate subclasses for processing of artificial intelligence.
707, Data Processing: Databases and File Management, or Data Structures,   appropriate subclasses for database structure, database/file management, or document processing.
709, Electrical Computers and Digital Processing Systems: Multicomputer Data Transferring or Plural Processor Synchronizaion,   appropriate subclasses for computers and digital processing related to plural computers or plural process coordinating.
710, Electrical Computers and Digital Data Processing Systems: Input/Output,   appropriate subclasses for input/output processing (e.g., bus processing) in a computer or digital data processing system.
711, Electrical Computers and Digital Processing Systems: Memory,   appropriate subclasses for storage accessing, control, or addressing in a computer or digital processing system.
712, Electrical Computers and Digital Processing Systems: Processing Architectures and Instruction Processing (e.g., Processors),   appropriate subclasses for computer or digital processing system architecture or instruction processing.
713, Electrical Computers and Digital Processing Systems: Support,   appropriate subclasses for computer or digital processing system support (e.g., security, power supply, and timing, etc. )
714, Error Detection/Correction and Fault Detection/Recovery,   appropriate subclasses for error or fault detection or compensation in a computer or digital processing system.
716, Computer-Aided Design and Analysis of Circuits and Semiconductor Masks,   appropriate subclasses.
717, Data Processing: Software Development, Installation, and Management,   appropriate subclasses.

SECTION III - GLOSSARY

CALCULATION OPERATIONS

Arithmetic or some limited logic operations performed upon or with signals representing numbers or values. These include arithmetic and related logic operations. A related logic operation is one that is associated with arithmetic computations.

DISCRETE ELECTRICAL SIGNAL

Discontinuous signals which can assume only a finite number of states.

NUMERICAL DIGITS

Symbols that represent a specific quantity or amount of units.

SUBCLASSES

[List of Patents for class 708 subclass 1]    1ELECTRICAL HYBRID CALCULATING COMPUTER:
 This subclass is indented under the class definition.  Subject matter wherein a calculation operation is performed either simultaneously or sequentially upon at least one analog and at least one digital signal or wherein either the analog or digital signal is involved in a calculation operation on the other signal.
(1) Note. This subclass does not include the mere conversion from one signal format to another, which conversion has no part in the above calculation operation.

SEE OR SEARCH THIS CLASS, SUBCLASS:

100+,for electrical digital calculating computers.
800+,for electrical analog calculating computers.
  
[List of Patents for class 708 subclass 2]    2Plural complete computers:
 This subclass is indented under subclass 1.  Subject matter which includes at least one complete analog computer and one complete digital computer.
  
[List of Patents for class 708 subclass 3]    3Particular function performed:
 This subclass is indented under subclass 1.  Subject matter directed to a particular function performed by hybrid computer or subcombination thereof in making computation.
(1) Note. For classification herein, the function performed must be significantly claimed in making a computation.
  
[List of Patents for class 708 subclass 4]    4Evaluation of trigonometric function:
 This subclass is indented under subclass 3.  Subject matter wherein the function performed is the processing of signal to either determine a trigonometric relationship or to operate on a signal in accordance with a trigonometric relationship.

SEE OR SEARCH THIS CLASS, SUBCLASS:

440,and 811+ for electrical digital or electrical analog computers which perform the function of evaluation of trigonometric functions.
  
[List of Patents for class 708 subclass 5]    5Correlation, convolution, or transformation:
 This subclass is indented under subclass 3.  Subject matter wherein the function performed is cross-correlation, autocorrelation, cross-convolution, autoconvolution or transforming a given representation of a data signal to another representation without loss of information by an orthogonal transformation.

SEE OR SEARCH THIS CLASS, SUBCLASS:

400+,420+, 422+, 813+, and 820+ for electrical digital or analog computers which perform the function of correlation, convolution or transformation.
  
[List of Patents for class 708 subclass 6]    6Integration or differentiation:
 This subclass is indented under subclass 3.  Subject matter wherein the function performed is integration or differentiation of at least one of a plurality of input signals.

SEE OR SEARCH THIS CLASS, SUBCLASS:

443,and 444, for electrical digital calculating differentiation and integration, respectively computers which perform.
822,and 823+, for electrical analog computers which perform differentiation and integration, respectively.
  
[List of Patents for class 708 subclass 7]    7Multiplication or division:
 This subclass is indented under subclass 3.  Subject matter wherein the function performed is multiplication or division to produce a product or quotient from at least two input signals.

SEE OR SEARCH THIS CLASS, SUBCLASS:

620+,and 650+, for electrical digital computers for performing the function of multiplication or division.
835+,and 844, for electrical analog computers for performing the function of multiplication or division.
  
[List of Patents for class 708 subclass 8]    8Function generation:
 This subclass is indented under subclass 3.  Subject matter wherein the function performed is the generation of at least one signal by mathematical operation or as part of a mathematical operation generates a signal representing a function of at least one variable input parameter.
(1) Note. This subclass includes a waveform synthesizer wherein the waveform is internally generated.

SEE OR SEARCH THIS CLASS, SUBCLASS:

270+,and 845+, for electrical digital or electrical analog computers which perform the function of function generation.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 100+ for miscellaneous signal converting, shaping, or generating circuits.
  
[List of Patents for class 708 subclass 9]    9Piece-wise linear synthesis:
 This subclass is indented under subclass 8.  Subject matter wherein the desired function is approximated by a series of segments of straight lines.

SEE OR SEARCH THIS CLASS, SUBCLASS:

846+,for analog computer piece-wise linear synthesis.
  
[List of Patents for class 708 subclass 100]    100ELECTRICAL DIGITAL CALCULATING COMPUTER:
 This subclass is indented under the class definition.  Subject matter wherein a calculation operation is performed upon discrete electrical signals representing a value normally described by numerical digits.
(1) Note. The value described includes a value represented by a pulse repetition rate.

SEE OR SEARCH THIS CLASS, SUBCLASS:

1+,for electrical hybrid calculating computers.
800+,for electrical analog calculating computers.

SEE OR SEARCH CLASS:

326, Electronic Digital Logic Circuitry,   appropriate subclasses for digital logic devices.
  
[List of Patents for class 708 subclass 101]    101Pulse repetition rate:
 This subclass is indented under subclass 100.  Subject matter wherein quantities are determinable from the pulse repetition frequency of the discrete electrical signal.

SEE OR SEARCH CLASS:

341, Coded Data Generation or Conversion,   subclasses 54+ for digital conversion where a bit is represented by a discrete frequency.
  
[List of Patents for class 708 subclass 102]    102Digital differential analyzer:
 This subclass is indented under subclass 101.  Subject matter utilized as a digital differential analyzer.

SEE OR SEARCH THIS CLASS, SUBCLASS:

804,for analog differential analyzers.
  
[List of Patents for class 708 subclass 103]    103Multiplication or division:
 This subclass is indented under subclass 101.  Subject matter wherein the operation performed on an electrical signal is multiplication or division.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 113+ for miscellaneous frequency control.
332, Modulators,   subclasses 112+ for pulse frequency modulators.
377, Electrical Pulse Counters, Pulse Dividers, or Shift Registers: Circuits and Systems,   appropriate subclasses for pulse dividing and multiplying circuits.
  
[List of Patents for class 708 subclass 104]    104Plural complete computers:
 This subclass is indented under subclass 100.  Subject matter which includes at least two complete digital computers.

SEE OR SEARCH THIS CLASS, SUBCLASS:

2,for a hybrid computer formed from plural complete computers.

SEE OR SEARCH CLASS:

700, Data Processing: Generic Control Systems or Specific Applications,   subclasses 2 through 7for plural programmable computers used in a generic control system.
  
[List of Patents for class 708 subclass 105]    105Combined with diverse art device:
 This subclass is indented under subclass 100.  Subject matter which includes a diverse art device having a noncalculating function, with common structure utilized in performing the calculating and the noncalculating functions, or an integrated unit into which the computer and diverse art device are embodied.
(1) Note. Search the art area of the diverse device for the details of the diverse device which are claimed.
  
[List of Patents for class 708 subclass 106]    106Checkbook:
 This subclass is indented under subclass 105.  Subject matter where the diverse device is a checkbook.

SEE OR SEARCH CLASS:

283, Printed Matter,   subclass 58 for banking checks, per se.
  
[List of Patents for class 708 subclass 107]    107Writing instrument (e.g., pen):
 This subclass is indented under subclass 105.  Subject matter where the diverse device is utilized for a hand-held marking purpose.

SEE OR SEARCH CLASS:

401, Coating Implements With Material Supply,   appropriate subclasses for pens or pencils, per se.
  
[List of Patents for class 708 subclass 108]    108Tape recorder:
 This subclass is indented under subclass 105.  Subject matter where the diverse device is a tape recorder.

SEE OR SEARCH CLASS:

360, Dynamic Magnetic Information Storage or Retrieval,   appropriate subclasses, for detail of a magnetic tape recorder, per se.
  
[List of Patents for class 708 subclass 109]    109Communication device (e.g., telephone, radio, television):
 This subclass is indented under subclass 105.  Subject matter where the diverse device transfers information between distant points.

SEE OR SEARCH CLASS:

348, Television,   subclass 552 for particular television structure combined with a calculator.
379, Telephonic Communications,   subclass 110.01 for particular telephonic substation structure combined with a calculator.
455, Telecommunications,   subclasses 344+ for particular receiver or analog modulated signal frequency converter structure combined with a calculator.
  
[List of Patents for class 708 subclass 110]    110Business device (e.g., billing, memorandum):
 This subclass is indented under subclass 105.  Subject matter where the diverse device is used in the conducting of trade.
(1) Note. Typical of subject matter found here would be a calculator of generic utility combined with a customer billing device.

SEE OR SEARCH CLASS:

705, Data Processing: Financial, Business Practice, Management, or Cost/Price Determination,   appropriate subclasses for data processing systems exclusively designed for or utilized in a business environment.
  
[List of Patents for class 708 subclass 111]    111Horological device:
 This subclass is indented under subclass 105.  Subject matter where the diverse device measures or indicates time.

SEE OR SEARCH CLASS:

368, Horology: Time Measuring Systems or Devices,   subclass 10 for a nominal digital calculating computer in combination with a horological device.
  
[List of Patents for class 708 subclass 112]    112Calendar:
 This subclass is indented under subclass 111.  Subject matter where the horological device provides indication of a day of the week or a date.

SEE OR SEARCH CLASS:

368, Horology: Time Measuring Systems or Devices,   subclasses 28+ for a calendar indicator, per se.
  
[List of Patents for class 708 subclass 130]    130Programmable calculator:
 This subclass is indented under subclass 100.  Subject matter which includes a calculator that is programmable.
(1) Note. Calculator does not include general purpose computers but is restricted to the limited capacity calculator such as desk calculator or a pocket calculator.

SEE OR SEARCH CLASS:

713, Electrical Computers and Digital Processing Systems: Support,   subclass 321 for a programmable calculator with power saving feature.
  
[List of Patents for class 708 subclass 131]    131Having specialized input:
 This subclass is indented under subclass 100.  Subject matter with specialized input in conjunction with calculation portion.
(1) Note. For classification herein, the calculating portion must be a significant component and the input to the calculating portion must be more than nominally recited.

SEE OR SEARCH CLASS:

200, Electricity: Circuit Makers and Breakers,   subclass 5 for a multiple switch assembly, per se.
235, Registers,   subclasses 145+ for keyboards.
341, Coded Data Generation or Conversion,   subclasses 22+ for a keyboard controlled code transmitting device.
345, Computer Graphics Processing and Selective Visual Display Systems,   subclasses 156+ for display peripheral interface input device.
348, Television,   subclass 552 for video input devices for computers.
710, Electrical Computers and Digital Data Processing Systems: Input/Output,   appropriate subclasses for input/output and bus data processing.
  
[List of Patents for class 708 subclass 132]    132Having supplemental environment related input:
 This subclass is indented under subclass 131.  Subject matter where input unique to a particular art area can be provided in addition to normal calculator input.
(1) Note. Typically found here is non-numeric environment related input.
  
[List of Patents for class 708 subclass 133]    133Cooking:
 This subclass is indented under subclass 132.  Subject matter where the supplemental input relates to the preparation of food for consumption.
(1) Note. Typical of subject matter found here is nonnumeric input designating a particular food to be cooked.

SEE OR SEARCH CLASS:

99, Foods and Beverages: Apparatus,   subclasses 324+ for particular cooking apparatus.
  
[List of Patents for class 708 subclass 134]    134Business:
 This subclass is indented under subclass 132.  Subject matter where the supplemental input relates to the conduct of trade.

SEE OR SEARCH CLASS:

705, Data Processing: Financial, Business Practice, Management, or Cost/Price Determination,   appropriate subclasses for data processing systems exclusively designed for or utilized in a business environment.
  
[List of Patents for class 708 subclass 135]    135For security:
 This subclass is indented under subclass 131.  Subject matter where a specialized input controls accessing of the calculating computer.

SEE OR SEARCH CLASS:

726, Information Security,   subclasses 1 through 36for information security in computers or digital processing system.
  
[List of Patents for class 708 subclass 136]    136Input verification:
 This subclass is indented under subclass 131.  Subject matter where the specialized input provides a check of intended versus actual input.
  
[List of Patents for class 708 subclass 137]    137Fraction input:
 This subclass is indented under subclass 131.  Subject matter where the specialized input permits entry of a fraction.
  
[List of Patents for class 708 subclass 138]    138Flexible input:
 This subclass is indented under subclass 131.  Subject matter in which some portion of the input is made nonrigid to facilitate data entry.
  
[List of Patents for class 708 subclass 139]    139Including specific computing system interconnection:
 This subclass is indented under subclass 131.  Subject matter for specific structure within the specialized input serving as an interface between the device actually manipulated by the operator and computing circuitry.
(1) Note. Included here would be keyboard input which includes specific structure linking the keyboard, per se, with computing circuitry, for example.
  
[List of Patents for class 708 subclass 140]    140Modular or overlay:
 This subclass is indented under subclass 131.  Subject matter where plug-in modules or overlays are utilized to effect data input.
  
[List of Patents for class 708 subclass 141]    141Including specific nonkeyboard-type information entry:
 This subclass is indented under subclass 131.  Subject matter where information ultimately conveyed to the calculating portion is produced by a particular device not having plural individually actuatable keys.
  
[List of Patents for class 708 subclass 142]    142Including specific keyboard-type information entry:
 This subclass is indented under subclass 131.  Subject matter where information ultimately conveyed to the calculating portion is produced by a particular device having plural individually actuatable keys.

SEE OR SEARCH CLASS:

200, Electricity: Circuit Makers and Breakers,   appropriate subclasses for switches, per se.
341, Coded Data Generation or Conversion,   subclasses 22+ for a keyboard controlled code transmitting device.
345, Computer Graphics Processing and Selective Visual Display Systems,   subclasses 168+ for display peripheral interface input device including keyboard.
  
[List of Patents for class 708 subclass 143]    143Nonmechanical key actuation:
 This subclass is indented under subclass 142.  Subject matter where input keys are operated by other than a push and release sequence (e.g., magnetic activation).

SEE OR SEARCH CLASS:

335, Electricity: Magnetically Operated Switches, Magnets, and Electromagnets,   appropriate subclasses for magnetic switches, per se.
337, Electricity: Electrothermally or Thermally Actuated Switches,   appropriate subclasses for thermal switches per se.
  
[List of Patents for class 708 subclass 144]    144User definable key:
 This subclass is indented under subclass 142.  Subject matter in which the user defines the function associated with a keyboard key.

SEE OR SEARCH CLASS:

345, Computer Graphics Processing and Selective Visual Display Systems,   subclass 172 for a display peripheral keyboard having a programmable function key.
  
[List of Patents for class 708 subclass 145]    145Plural function key:
 This subclass is indented under subclass 142.  Subject matter where a keyboard key has plurality of selectable predetermined functions associated with it.
  
[List of Patents for class 708 subclass 146]    146Key sequencing (i.e., sequence defines function):
 This subclass is indented under subclass 142.  Subject matter where the order in which a plurality of keys is actuated determines the function to be performed.
  
[List of Patents for class 708 subclass 160]    160Having specialized output:
 This subclass is indented under subclass 100.  Subject matter with specialized output in conjunction with calculating portion.
(1) Note. For classification herein, the calculating portion must be a significant component and the output from the calculating portion must be more than nominally recited.

SEE OR SEARCH CLASS:

340, Communications: Electrical,   subclasses 815.4+ for visual indicators.
345, Computer Graphics Processing and Selective Visual Display Systems,   appropriate subclasses for selective visual display systems and computer graphics processing.
710, Electrical Computers and Digital Data Processing Systems: Input/Output,   appropriate subclasses for input/output and bus data processing.
  
[List of Patents for class 708 subclass 161]    161Having supplemental environment related output:
 This subclass is indented under subclass 160.  Subject matter where output unique to a particular art area can be provided in addition to normal calculator output.
(1) Note. Typically found here is non-numeric environment related output.
  
[List of Patents for class 708 subclass 162]    162Teaching:
 This subclass is indented under subclass 161.  Subject matter where the supplemental output relates to education.

SEE OR SEARCH CLASS:

434, Education and Demonstration,   appropriate subclasses for instructional devices, per se.
  
[List of Patents for class 708 subclass 163]    163Business:
 This subclass is indented under subclass 161.  Subject matter where the supplemental output relates to the conduct of trade.

SEE OR SEARCH CLASS:

705, Data Processing: Financial, Business Practice, Management, or Cost/Price Determination,   appropriate subclasses for data processing systems exclusively designed for or utilized in a business environment.
  
[List of Patents for class 708 subclass 164]    164Output verification:
 This subclass is indented under subclass 160.  Subject matter in which the output is provided in a form permitting checking thereof (e.g., trace).
  
[List of Patents for class 708 subclass 165]    165Blanking:
 This subclass is indented under subclass 160.  Subject matter where the specialized output has provision for suppressing a selected portion of the output.
  
[List of Patents for class 708 subclass 166]    166Zero suppression:
 This subclass is indented under subclass 165.  Subject matter wherein the blanking means has zero suppression capability.
  
[List of Patents for class 708 subclass 167]    167Prompting:
 This subclass is indented under subclass 160.  Subject matter where the specialized output provides the user with guidance regarding future information entry.
  
[List of Patents for class 708 subclass 168]    168Selective output:
 This subclass is indented under subclass 160.  Subject matter where the specialized output permits choosing the desired output from a plurality of candidates.

SEE OR SEARCH THIS CLASS, SUBCLASS:

174,for multiple simultaneous outputs.
  
[List of Patents for class 708 subclass 169]    169Sequential output:
 This subclass is indented under subclass 160.  Subject matter where the specialized output provides successive portions of a desired output one at a time.
  
[List of Patents for class 708 subclass 170]    170Using particular format:
 This subclass is indented under subclass 160.  Subject matter where the specialized output provides the output in a specified form.
(1) Note. The particular format might be engineering notation or floating point, for example.
  
[List of Patents for class 708 subclass 171]    171Symbol accompanying output:
 This subclass is indented under subclass 160.  Subject matter in which the specialized output provides a special symbol with the output representation.
  
[List of Patents for class 708 subclass 172]    172Audio:
 This subclass is indented under subclass 160.  Subject matter where the specialized output is in audible form.

SEE OR SEARCH CLASS:

381, Electrical Audio Signal Processing Systems and Devices,   appropriate subclasses for electrical audio signal processing in general.
700, Data Processing: Generic Control Systems or Specific Applications,   subclasses 2 through 7for plural programmable computers used in a generic control system.
  
[List of Patents for class 708 subclass 173]    173Printer:
 This subclass is indented under subclass 160.  Subject matter in which the specialized output provides the output representation in permanent readable form.

SEE OR SEARCH CLASS:

347, Incremental Printing of Symbolic Information,   appropriate subclasses for incremental printing (e.g., ink jet printing).
358, Facsimile and Static Presentation Processing,   subclasses 1.1 through 1.18for static presentation processing (e.g., processing data for printer, etc.).
  
[List of Patents for class 708 subclass 174]    174Multiple simultaneous outputs:
 This subclass is indented under subclass 160.  Subject matter where a plurality of output representations are made available by the specialized output at the same time.

SEE OR SEARCH THIS CLASS, SUBCLASS:

168,for selective output.
  
[List of Patents for class 708 subclass 190]    190Integrated circuit:
 This subclass is indented under subclass 100.  Subject matter wherein the calculating is effected by an integrated circuit or chip, the use or specific structure or arrangement of which significantly affects or directs the handling of information.

SEE OR SEARCH CLASS:

257, Active Solid-State Devices (e.g., Transistors, Solid-State Diodes),   appropriate subclasses for integrated circuit structure with active solid-state devices, subclasses 446 and 499+ for integrated circuit devices with electrically isolated components, in general, and other appropriate subclasses for specific type devices in integrated circuits.
326, Electronic Digital Logic Circuitry,   subclasses 101+ for electronic logic with significant integrated structure.
327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 564+ for miscellaneous circuits with integrated structure.
  
[List of Patents for class 708 subclass 191]    191Electro-optical:
 This subclass is indented under subclass 100.  Subject matter wherein the calculating is effected by electro-optical devices.

SEE OR SEARCH CLASS:

359, Optics: Systems and Elements subclasses 107+ for optical computing without diffraction and subclasses 237+ for optical modulators.
  
[List of Patents for class 708 subclass 192]    192Bubble-domain:
 This subclass is indented under subclass 100.  Subject matter wherein the calculating is effected by bubble-domain devices.

SEE OR SEARCH CLASS:

365, Static Information Storage and Retrieval,   subclasses 1+ for magnetic bubble-domain devices used for storage of information.
  
[List of Patents for class 708 subclass 200]    200Particular function performed:
 This subclass is indented under subclass 100.  Subject matter having a particular function involving a calculation performed by digital computer or subcombination thereof.
(1) Note. For classification herein, the calculating performed in effecting the function must be significantly claimed.

SEE OR SEARCH CLASS:

712, Electrical Computers and Digital Processing Systems: Processing Architectures and Instruction Processing ( e.g., Processors),   subclasses 1+ for particular processing architecture which could be utilized in performing the particular function.
  
[List of Patents for class 708 subclass 201]    201Absolute value or magnitude:
 This subclass is indented under subclass 200.  Subject matter wherein the particular function determines the absolute value or magnitude of a result from an arithmetic operation.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclass 354 for a specific input-to-output function performed by an absolute value.
  
[List of Patents for class 708 subclass 202]    202Median:
 This subclass is indented under subclass 200.  Subject matter wherein the particular function provides the middle value in a series.
  
[List of Patents for class 708 subclass 203]    203Compression/decompression:
 This subclass is indented under subclass 200.  Subject matter for representing a number or group of numbers by a smaller number of digits than that possessed originally or the inverse operation.

SEE OR SEARCH CLASS:

341, Coded Data Generation or Conversion,   subclass 60 for digital conversion to or from a packed format.
348, Television,   subclasses 384+ for a bandwidth reduction system.
382, Image Analysis,   subclasses 232+ for data compression in an image processing system.
709, Electrical Computer and Digital Processing Systems: Multicomputer Data Transferring or Plural Processor Synchronizaion,   subclasses 247+ for data compressing/decompressing in computer data transfer.
  
[List of Patents for class 708 subclass 204]    204Format conversion:
 This subclass is indented under subclass 200.  Subject matter for changing a number having a representation in one form to a representation in another form.

SEE OR SEARCH CLASS:

341, Coded Data Generation or Conversion,   subclasses 50+ for digital-to-digital converters.
  
[List of Patents for class 708 subclass 205]    205Normalization:
 This subclass is indented under subclass 204.  Subject matter in which the number in final form includes a single nonzero digit to the left of a radix point.

SEE OR SEARCH THIS CLASS, SUBCLASS:

495+,for floating point systems.
  
[List of Patents for class 708 subclass 206]    206Unit conversion:
 This subclass is indented under subclass 200.  Subject matter where a number reflecting a first system of measurement is changed to reflect a second system of measurement.
(1) Note. Included here are such conversions as English to metric.
  
[List of Patents for class 708 subclass 207]    207Maximum/minimum determination:
 This subclass is indented under subclass 200.  Subject matter in which the largest or smallest of a group of numbers is found.
  
[List of Patents for class 708 subclass 208]    208Scaling:
 This subclass is indented under subclass 200.  Subject matter where a number is modified by a predetermined multiplicative factor.
  
[List of Patents for class 708 subclass 209]    209Shifting:
 This subclass is indented under subclass 200.  Subject matter where a number is changed by moving each digit therein simultaneously a specified number of positions in a specified direction.
(1) Note. Digits that are shifted beyond the confines of the number may or may not be recirculated into the opposite end of the number. Fixed digits may be inserted there instead.

SEE OR SEARCH CLASS:

377, Electrical Pulse Counters, Pulse Dividers, or Shift Registers: Circuits and Systems,   appropriate subclasses for shift registers.
712, Electrical Computers and Digital Processing Systems: Processing Architectures and Instruction Processing (e.g., Processors),   subclass 898 for byte word order rearranging.
  
[List of Patents for class 708 subclass 210]    210Determining number of like-valued bits in word:
 This subclass is indented under subclass 200.  Subject matter where the number of 1"s or the number of 0"s in a binary word is determined.
  
[List of Patents for class 708 subclass 211]    211Determining number of like-valued leading or trailing bits:
 This subclass is indented under subclass 200.  Subject matter where the number of consecutive leading or trailing 1"s or 0"s in a binary word is determined.
  
[List of Patents for class 708 subclass 212]    212Detecting particular sequence of bits:
 This subclass is indented under subclass 200.  Subject matter for locating a particular string of bits in a larger string of bits.

SEE OR SEARCH CLASS:

375, Pulse or Digital Communications,   subclasses 354+ for synchronizers, per se.
712, Electrical Computers and Digital Processing Systems: Processing Architectures and Instruction Processing (e.g., Processors),   subclass 898 for byte-word sequence detecting.
  
[List of Patents for class 708 subclass 230]    230Multifunctional:
 This subclass is indented under subclass 200.  Subject matter wherein the electric digital calculating computer provides for selectively performing at least one logical operation as well as at least one arithmetical operation relative to operands (e.g., a programmable logic circuit with computational means).

SEE OR SEARCH CLASS:

307, Electrical Transmission or Interconnection Systems,   subclasses 407+ for nonlinear reactor logic circuits.
326, Electronic Digital Logic Circuitry,   subclasses 37+ for programmable logic circuits not performing arithmetic calculations and which are typically solid state.
365, Static Information Storage and Retrieval,   appropriate subclasses for programmable logic circuits which include storage and retrieval of information.
  
[List of Patents for class 708 subclass 231]    231Microprocessor:
 This subclass is indented under subclass 230.  Subject matter wherein the multifunctional operation is performed by a microprocessor.

SEE OR SEARCH THIS CLASS, SUBCLASS:

303,for a particular microprocessor used in a filtering operation.
510,for a particular microprocessor used in floating point.

SEE OR SEARCH CLASS:

712, Electrical Computers and Digital Processing Systems: Processing Architectures and Instruction Processing (e.g., Processors),   subclasses 32+ for particular microprocessor architecture.
  
[List of Patents for class 708 subclass 232]    232Array of elements (e.g., AND/OR array, etc.):
 This subclass is indented under subclass 230.  Subject matter wherein the multifunctional operation is performed by a group of many similar, basic, complex, or integrated elements without separated enclosures, such as AND/OR arrays, etc.
  
[List of Patents for class 708 subclass 233]    233Pipeline:
 This subclass is indented under subclass 230.  Subject matter wherein the multifunctional operation is performed in a pipeline where the output of one task is input to another until a desired sequence of tasks has been carried out.

SEE OR SEARCH THIS CLASS, SUBCLASS:

406,for Fourier transformation performed in a particular pipeline.
508,for floating point performed in a particular pipeline.
521,for arithmetical pipeline operation in general.
631,for multiple digit binary multiplication performed in a particular pipeline.
  
[List of Patents for class 708 subclass 234]    234Parallel bit input of operand:
 This subclass is indented under subclass 230.  Subject matter wherein the multifunctional operation is performed in bit level and the bits of operands are input in parallel.
  
[List of Patents for class 708 subclass 235]    235Uses look-up table:
 This subclass is indented under subclass 230.  Subject matter wherein the operation involves a look-up table to search for a desired item of information.
  
[List of Patents for class 708 subclass 236]    236More than two operands:
 This subclass is indented under subclass 230.  Subject matter wherein the operations involve three or more operands.
  
[List of Patents for class 708 subclass 250]    250Random number generation:
 This subclass is indented under subclass 200.  Subject matter wherein the computer generates a number or sequence of numbers characterized by unpredictability so that no number is any more likely to occur at a given time or place in a sequence than any other.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclass 164 for a miscellaneous circuit producing a rectangular waveform having a random characteristic (e.g., random width).
331, Oscillators,   subclass 78 for electrical noise or random wave generation by oscillators (e.g., random pulse generators).
  
[List of Patents for class 708 subclass 251]    251Oscillator controlled:
 This subclass is indented under subclass 250.  Subject matter wherein the generation is effected by an oscillator or clock.
  
[List of Patents for class 708 subclass 252]    252Linear feedback shift register:
 This subclass is indented under subclass 250.  Subject matter wherein the generation is performed by a feedback shift register in which a proportional relationship exists between an input and output.

SEE OR SEARCH CLASS:

377, Electrical Pulse Counters, Pulse Dividers, or Shift Registers: Circuits and Systems,   appropriate subclasses for a shift register, per se.
  
[List of Patents for class 708 subclass 253]    253Plural parallel output bits:
 This subclass is indented under subclass 250.  Subject matter wherein the generation produces plural bits of a sequence in parallel.

SEE OR SEARCH THIS CLASS, SUBCLASS:

256,for plural parallel outputs.
  
[List of Patents for class 708 subclass 254]    254Seed value controls:
 This subclass is indented under subclass 250.  Subject matter wherein seed value is used as an initial value in the generation.
  
[List of Patents for class 708 subclass 255]    255Truly random number:
 This subclass is indented under subclass 250.  Subject matter wherein the generation produces a random sequence which is not repeated.
  
[List of Patents for class 708 subclass 256]    256Plural parallel outputs:
 This subclass is indented under subclass 250.  Subject matter wherein the generation produces plural sequences in parallel.

SEE OR SEARCH THIS CLASS, SUBCLASS:

253,for plural parallel output bits.
  
[List of Patents for class 708 subclass 270]    270Function generation:
 This subclass is indented under subclass 200.  Subject matter wherein a sequence of discrete values is generated to represent a desired waveform.

SEE OR SEARCH THIS CLASS, SUBCLASS:

8+,and 845+, for electrical hybrid or electrical analog computers which perform the function of function generation.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 100+ for miscellaneous signal converting, shaping, or generating circuits.
  
[List of Patents for class 708 subclass 271]    271Direct digital frequency synthesizer:
 This subclass is indented under subclass 270.  Subject matter wherein the generation is performed by a digital frequency source capable of producing a multitude of output frequencies from the desired frequency of the waveform.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 105+ for a synthesizer converting, shaping, or generating a nonlinear signal.
  
[List of Patents for class 708 subclass 272]    272Memory used to store waveshape:
 This subclass is indented under subclass 270.  Subject matter wherein a circuit allows a waveshape to be stored and retrieved for generating the waveform.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclass 106 for waveform or waveshape determinative circuits including stored data.
  
[List of Patents for class 708 subclass 273]    273Counter as source (i.e., input):
 This subclass is indented under subclass 270.  Subject matter wherein a circuit counts input pulses for producing phase increments as a source.
  
[List of Patents for class 708 subclass 274]    274Linear:
 This subclass is indented under subclass 270.  Subject matter where the desired waveform is linear.

SEE OR SEARCH THIS CLASS, SUBCLASS:

8,for a hybrid computer providing piece-wise linear synthesis.
852,for analog triangular, sawtooth or ramp function generation.
  
[List of Patents for class 708 subclass 275]    275Circular:
 This subclass is indented under subclass 270.  Subject matter where the desired waveform represents a circular relationship.
  
[List of Patents for class 708 subclass 276]    276Trigonometric:
 This subclass is indented under subclass 270.  Subject matter where the desired waveform has trigonometric relationships.
  
[List of Patents for class 708 subclass 277]    277Logarithmic/exponential:
 This subclass is indented under subclass 270.  Subject matter where the desired waveform is logarithmic or exponential.

SEE OR SEARCH THIS CLASS, SUBCLASS:

851,for analog logarithmic/exponential function generation.
  
[List of Patents for class 708 subclass 290]    290Interpolation/extrapolation:
 This subclass is indented under subclass 200.  Subject matter for the determination or estimation of a value or values of a function between two known values or of the trend established between two or more known points.

SEE OR SEARCH THIS CLASS, SUBCLASS:

313,for decimation/interpolation in digital filtering.
847,for interpolation/extrapolation in analog piece-wise linear function synthesis.

SEE OR SEARCH CLASS:

318, Electricity: Motive Power Systems,   subclass 573 for interpolation in positional servo systems.
  
[List of Patents for class 708 subclass 300]    300Filtering:
 This subclass is indented under subclass 200.  Subject matter wherein a computational process or algorithm separates data, signals, or materials in accordance with specified criteria.

SEE OR SEARCH THIS CLASS, SUBCLASS:

819,for analog computer filtering.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 551+ for miscellaneous unwanted signal suppression utilizing an active filter circuit not performing an arithmetic calculation.
702, Data Processing: Measuring, Calibrating, or Testing,   subclasses 190+ for signal extraction or separation in measured signal processing.
  
[List of Patents for class 708 subclass 301]    301Tapped delay line:
 This subclass is indented under subclass 300.  Subject matter wherein a delay line, in which more than two terminal pairs are associated with a single delay channel, is used to provide delayed signals.

SEE OR SEARCH THIS CLASS, SUBCLASS:

425,for correlation using tapped delay line.
  
[List of Patents for class 708 subclass 303]    303Microprocessor:
 This subclass is indented under subclass 300.  Subject matter wherein the filtering is performed by a microprocessor.

SEE OR SEARCH THIS CLASS, SUBCLASS:

231,for a particular microprocessor used in the multifunctional operation.
510,for a particular microprocessor used in floating point.

SEE OR SEARCH CLASS:

712, Electrical Computers and Digital Processing Systems: Processing Architectures and Instruction Processing (e.g., Processors) subclasses 32+ for particular microprocessor architecture.
  
[List of Patents for class 708 subclass 304]    304Nonlinear (e.g., median, etc.):
 This subclass is indented under subclass 300.  Subject matter wherein the relationship between the pertinent measures of the input and output signals cannot be adequately described by linear means (e.g., median filter).

SEE OR SEARCH CLASS:

382, Image Analysis,   subclass 262 for a median image filter.
  
[List of Patents for class 708 subclass 305]    305Initialization:
 This subclass is indented under subclass 300.  Subject matter where the filter is placed in a beginning state prior to the actual processing.
  
[List of Patents for class 708 subclass 306]    306Finite arithmetic effect:
 This subclass is indented under subclass 300.  Subject matter for indication or compensation of an effect arising from the use of operands having a finite length representation.
(1) Note. Included here are such effects as overflow, underflow and oscillation.

SEE OR SEARCH THIS CLASS, SUBCLASS:

496,for floating point compensation for finite word length.
  
[List of Patents for class 708 subclass 307]    307Delta/differential coded:
 This subclass is indented under subclass 300.  Subject matter in which the samples used in processing are present in the delta or differential coded format.

SEE OR SEARCH CLASS:

341, Coded Data Generation or Conversion,   subclasses 76+ for digital conversion to or from a differential code.
  
[List of Patents for class 708 subclass 308]    308Multidimensional data:
 This subclass is indented under subclass 300.  Subject matter where the data to be processed is multidimensional (e.g., image data).

SEE OR SEARCH CLASS:

382, Image Analysis,   subclasses 254+ for image enhancement which may include filtering.
  
[List of Patents for class 708 subclass 309]    309Frequency measurement:
 This subclass is indented under subclass 300.  Subject matter where frequency determination is accomplished by first removing from a signal corrupting noise which was imposed by a transmission medium.

SEE OR SEARCH CLASS:

324, Electricity: Measuring and Testing,   subclasses 76.39+ for frequency measurement of cyclic current or voltage in general.
702, Data Processing: Measuring, Calibrating, or Testing,   subclasses 75+ for electrical frequency measurement, per se.
  
[List of Patents for class 708 subclass 310]    310Coherent:
 This subclass is indented under subclass 300.  Subject matter where a particular frequency is eliminated from a signal.
  
[List of Patents for class 708 subclass 311]    311Frequency detection:
 This subclass is indented under subclass 300.  Subject matter in which a subset of frequencies from a known set of possible frequencies is determined to be present.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 39+ for discriminating by frequency.
  
[List of Patents for class 708 subclass 312]    312Tone detection:
 This subclass is indented under subclass 310.  Subject matter where the subset consists of a single frequency.
  
[List of Patents for class 708 subclass 313]    313Decimation/interpolation:
 This subclass is indented under subclass 300.  Subject matter where the filter deletes from or adds to the samples input to it in a specified regular fashion resulting in a net sampling rate change.

SEE OR SEARCH THIS CLASS, SUBCLASS:

290,for interpolation, per se.
  
[List of Patents for class 708 subclass 314]    314Matched filter type:
 This subclass is indented under subclass 300.  Subject matter for maximizing the signal-to-noise ratio through the use of filters utilizing correlation techniques.

SEE OR SEARCH CLASS:

375, Pulse or Digital Communications,   subclass 343 for pulse demodulation or detection by matched filters.
  
[List of Patents for class 708 subclass 315]    315By convolution:
 This subclass is indented under subclass 300.  Subject matter in which a convolution technique is utilized to accomplish the filtering.

SEE OR SEARCH THIS CLASS, SUBCLASS:

420+,for digital convolution, per se.
  
[List of Patents for class 708 subclass 316]    316Having multiplexing:
 This subclass is indented under subclass 300.  Subject matter where one of a plurality of signals is selected and processed by a given filter or one of a plurality of filters is selected to process a given signal.
  
[List of Patents for class 708 subclass 317]    317Wave:
 This subclass is indented under subclass 300.  Subject matter in which the filter has elements representing distributed parameters.

SEE OR SEARCH CLASS:

333, Wave Transmission Lines and Networks,   subclasses 202+ for analog wave filters.
  
[List of Patents for class 708 subclass 318]    318Lattice:
 This subclass is indented under subclass 300.  Subject matter in which the filter has four computational or delay elements connected in series to form a closed circuit with two nonadjacent ports serving as the input terminals with the other two ports serving as output terminals.

SEE OR SEARCH CLASS:

333, Wave Transmission Lines and Networks,   subclass 169 for analog lattice filters.
  
[List of Patents for class 708 subclass 319]    319Transversal:
 This subclass is indented under subclass 300.  Subject matter in which feedforward processing of present inputs is utilized.

SEE OR SEARCH THIS CLASS, SUBCLASS:

425,for correlation using tapped delay line.
  
[List of Patents for class 708 subclass 320]    320Recursive:
 This subclass is indented under subclass 300.  Subject matter in which the present filter output is a function of present inputs and past filter outputs.
  
[List of Patents for class 708 subclass 321]    321Nontime domain:
 This subclass is indented under subclass 300.  Subject matter where the data when processed is not in the time domain.
(1) Note. Frequently this data is in the frequency domain.
  
[List of Patents for class 708 subclass 322]    322Adaptive:
 This subclass is indented under subclass 300.  Subject matter where the transfer function of the filter is automatically changed as a function of the input signal.
  
[List of Patents for class 708 subclass 323]    323Equalizer:
 This subclass is indented under subclass 321.  Subject matter where adaptive compensation for transmission medium noise imposition is performed.

SEE OR SEARCH CLASS:

375, Pulse or Digital Communications,   subclasses 229+ for equalizers in a digital communications system.
  
[List of Patents for class 708 subclass 400]    400Transform:
 This subclass is indented under subclass 200.  Subject matter wherein the digital calculation performs a transformation of a given representation of a data signal to another representation without loss of information by an orthogonal transformation.

SEE OR SEARCH CLASS:

704, Data Processing: Speech Signal Processing, Linguistics, Language Translation, and Audio Compression/Decompression,   subclasses 200+ for speech signal processing.
  
[List of Patents for class 708 subclass 401]    401Multidimensional:
 This subclass is indented under subclass 400.  Subject matter including a specific apparatus which is used for computing an n-dimensional transform of an input signal with n greater or equal to two.
  
[List of Patents for class 708 subclass 402]    402Discrete Cosine Transform (i.e., DCT):
 This subclass is indented under subclass 400.  Subject matter wherein the transformation performed is a Discrete Cosine Transform.
  
[List of Patents for class 708 subclass 403]    403Fourier:
 This subclass is indented under subclass 400.  Subject matter wherein the transformation performed is a mathematical operation which decomposes a time varying signal into its complex frequency components (amplitude and the phase or real and imaginary components).

SEE OR SEARCH CLASS:

382, Image Analysis,   subclass 280 for a Fourier transform performed on image data.
  
[List of Patents for class 708 subclass 404]    404Fast Fourier Transform (i.e., FFT):
 This subclass is indented under subclass 403.  Subject matter wherein the transformation performed is a Fast Fourier Transform.

SEE OR SEARCH THIS CLASS, SUBCLASS:

405,for Discrete Fourier Transform.
  
[List of Patents for class 708 subclass 405]    405Discrete Fourier Transform (i.e., DFT):
 This subclass is indented under subclass 403.  Subject matter wherein the transformation performed is a Discrete Fourier Transform.

SEE OR SEARCH THIS CLASS, SUBCLASS:

404,for Fast Fourier Transform.
  
[List of Patents for class 708 subclass 406]    406Pipeline:
 This subclass is indented under subclass 403.  Subject matter wherein the transformation is performed in a pipeline where the output of one task is input to another until a desired sequence of tasks has been carried out.

SEE OR SEARCH THIS CLASS, SUBCLASS:

233,for multifunctional operation performed in a particular pipeline.
508,for floating point performed in a particular pipeline.
521,for arithmetical pipeline operation in general.
631,for multiple digit binary multiplication performed in a particular pipeline.
  
[List of Patents for class 708 subclass 407]    407Systolic:
 This subclass is indented under subclass 403.  Subject matter wherein the transformation is performed by a specific apparatus having an array of computational elements where data is transferred synchronously between nearest neighbor elements.

SEE OR SEARCH THIS CLASS, SUBCLASS:

509,for a particular systolic array used in floating point.
522,for a particular systolic array used in an arithmetical operation.

SEE OR SEARCH CLASS:

712, Electrical Computers and Digital Processing Systems: Processing Architectures and Instruction Processing ( e.g., Processors) subclass 19 for systolic array processor architecture.
  
[List of Patents for class 708 subclass 408]    408Radix greater than two:
 This subclass is indented under subclass 403.  Subject matter wherein a specific apparatus is used for computing an n-radix Fourier Transform with n greater than two.
  
[List of Patents for class 708 subclass 409]    409Butterfly circuit:
 This subclass is indented under subclass 403.  Subject matter wherein a specific apparatus performs a complex multiplication and a complex addition or subtraction.
  
[List of Patents for class 708 subclass 410]    410Walsh:
 This subclass is indented under subclass 400.  Subject matter wherein the transformation performed is a Walsh Transform.

SEE OR SEARCH CLASS:

382, Image Analysis,   subclass 281 for image transformation or processing using a Walsh Transform.
  
[List of Patents for class 708 subclass 420]    420Convolution:
 This subclass is indented under subclass 200.  Subject matter which the convolution integral is evaluated in a digital fashion.
(1) Note. Frequently, the output of a system is determined by convolving the system input with the system impulse response.

SEE OR SEARCH THIS CLASS, SUBCLASS:

5,for hybrid computer convolution.
315,for convolution in digital filtering.
813+,for analog computer convolution.

SEE OR SEARCH CLASS:

382, Image Analysis,   subclass 279 for convolution in image preliminary processing or transformation.
  
[List of Patents for class 708 subclass 421]    421Cyclic/circular:
 This subclass is indented under subclass 420.  Subject matter where the convolution integral of a and b, two series of discrete values, is found by performing a transform operation on a and b (producing A and B respectively) and then performing the inverse transform operation on the product of A and B.
  
[List of Patents for class 708 subclass 422]    422Correlation:
 This subclass is indented under subclass 200.  Subject matter where the particular function determines the degree of correspondence between two series of discrete values by digitally evaluating the correlation integral.

SEE OR SEARCH THIS CLASS, SUBCLASS:

5,for hybrid computer correlation.
813+,for analog computer correlation.

SEE OR SEARCH CLASS:

382, Image Analysis,   subclass 278 for correlation in image preliminary processing or transformation.
  
[List of Patents for class 708 subclass 423]    423Single bit data:
 This subclass is indented under subclass 422.  Subject matter in which the discrete values have a one bit representation.
  
[List of Patents for class 708 subclass 424]    424Multidimensional data:
 This subclass is indented under subclass 422.  Subject matter in which at least one series of discrete values is multidimensional (e.g., image data).

SEE OR SEARCH THIS CLASS, SUBCLASS:

814,for analog correlation of multidimensional data.

SEE OR SEARCH CLASS:

382, Image Analysis,   subclass 278 for correlation used in image transformation or prerecognition processing.
  
[List of Patents for class 708 subclass 425]    425Using tapped delay line:
 This subclass is indented under subclass 422.  Subject matter where the outputs from successive stages of a digital delay element are utilized.

SEE OR SEARCH THIS CLASS, SUBCLASS:

301+,for related structure utilized in a filtering environment.
818,for analog correlation having a tapped delay line.
  
[List of Patents for class 708 subclass 426]    426Autocorrelation:
 This subclass is indented under subclass 422.  Subject matter in which both series of discrete values are from a single source.
  
[List of Patents for class 708 subclass 440]    440Evaluation of trigonometric function:
 This subclass is indented under subclass 200.  Subject matter wherein the particular function performed is the processing of a signal either to determine a trigonometric relationship or to operate on a signal in accordance with a trigonometric relationship.

SEE OR SEARCH THIS CLASS, SUBCLASS:

276,for waveform generation having trigonometric relationships.
811,for evaluation of trigonometric function by analog computer.
  
[List of Patents for class 708 subclass 441]    441Vector resolver:
 This subclass is indented under subclass 440.  Subject matter wherein the signal is a vector and the operation is determining the vector components.

SEE OR SEARCH THIS CLASS, SUBCLASS:

809,for a vector resolver using analog computer.
  
[List of Patents for class 708 subclass 442]    442Coordinate conversion:
 This subclass is indented under subclass 200.  Subject matter wherein the particular function performed is conversion of coordinates from one coordinate system to another (e.g., rectangular to polar).
(1) Note. The calculation of the change in coordinates resulting from a translation or rotation of a reference coordinate system is included in this subclass.

SEE OR SEARCH THIS CLASS, SUBCLASS:

809,for a coordinate conversion using analog computer.
  
[List of Patents for class 708 subclass 443]    443Differentiation:
 This subclass is indented under subclass 200.  Subject matter for differentiation of at least one of a plurality of input signals.

SEE OR SEARCH THIS CLASS, SUBCLASS:

6,for hybrid computer differentiation.
822,for analog differentiation.
  
[List of Patents for class 708 subclass 444]    444Integration:
 This subclass is indented under subclass 200.  Subject matter for the integration of a sequence of discrete values of an input signal.

SEE OR SEARCH THIS CLASS, SUBCLASS:

6,for hybrid computer integration.
823+,for analog integration.
  
[List of Patents for class 708 subclass 445]    445Averaging:
 This subclass is indented under subclass 200.  Subject matter for determining the average of a sequence of discrete values.

SEE OR SEARCH THIS CLASS, SUBCLASS:

805,for analog computer averaging.

SEE OR SEARCH CLASS:

702, Data Processing: Measuring, Calibrating, or Testing,   subclass 194 for averaging in measured signal noise suppression.
  
[List of Patents for class 708 subclass 446]    446Solving equation:
 This subclass is indented under subclass 200.  Subject matter wherein the specialized function performed is to solve an equation.
(1) Note. Excluded are arithmetical operations.

SEE OR SEARCH THIS CLASS, SUBCLASS:

490+,for digital arithmetical operations.
  
[List of Patents for class 708 subclass 490]    490Arithmetical operation:
 This subclass is indented under subclass 200.  Subject matter wherein numerical quantities form the elements of the calculation, including the fundamental operations of arithmetic (addition, subtraction, multiplication, comparison, and division).
  
[List of Patents for class 708 subclass 491]    491Residue number:
 This subclass is indented under subclass 490.  Subject matter wherein the numerical digits are in the residue number system.

SEE OR SEARCH THIS CLASS, SUBCLASS:

532,for residue code error detection or correction.
  
[List of Patents for class 708 subclass 492]    492Galois field:
 This subclass is indented under subclass 490.  Subject matter where the arithmetical operations are performed on a 2 m element finite arithmetic field.
  
[List of Patents for class 708 subclass 493]    493Multi-valued:
 This subclass is indented under subclass 490.  Subject matter where the arithmetical operations are performed with multi-valued operands.
  
[List of Patents for class 708 subclass 494]    494Incremental mode:
 This subclass is indented under subclass 490.  Subject matter wherein the numerical digits represent a change in numbers as opposed to whole number representation.

SEE OR SEARCH CLASS:

375, Pulse or Digital Communications,   subclasses 247+ for delta modulation.
  
[List of Patents for class 708 subclass 495]    495Floating point:
 This subclass is indented under subclass 490.  Subject matter wherein the numerical digits are expressed in terms of a bounded number (mantissa) and a scale factor (characteristic or exponent) consisting of a power of the number base.
  
[List of Patents for class 708 subclass 496]    496Compensation for finite word length:
 This subclass is indented under subclass 495.  Subject matter wherein the operation results in a word modification in length due to insufficient representation of using the fixed word length of the arithmetic system.

SEE OR SEARCH THIS CLASS, SUBCLASS:

306,for finite arithmetic effect in digital filtering.
550+,for compensation for finite word length used in arithmetical operations.
  
[List of Patents for class 708 subclass 497]    497Round off or truncation:
 This subclass is indented under subclass 496.  Subject matter wherein the modification is a deletion of one or more of the least significant digits and an adjustment of the more significant digits in accordance with some specific rule.

SEE OR SEARCH THIS CLASS, SUBCLASS:

551,for round off or truncation in arithmetical operations.
  
[List of Patents for class 708 subclass 498]    498Overflow or underflow:
 This subclass is indented under subclass 496.  Subject matter wherein the modification is necessary because the word is either too large or too small to be represented using the fixed word length.

SEE OR SEARCH THIS CLASS, SUBCLASS:

552,for overflow or underflow used in arithmetical operations.
  
[List of Patents for class 708 subclass 499]    499Sticky bit:
 This subclass is indented under subclass 496.  Subject matter wherein the modification is based on whether or not a number of least significant digits contains a one.
  
[List of Patents for class 708 subclass 500]    500Evaluation of root:
 This subclass is indented under subclass 495.  Subject matter wherein the operation performed is the determination of a root.

SEE OR SEARCH THIS CLASS, SUBCLASS:

605,for evaluation of root by digital arithmetic operations.
807,for analog evaluation of root.
  
[List of Patents for class 708 subclass 501]    501Multiplication followed by addition:
 This subclass is indented under subclass 495.  Subject matter wherein the operation performed is multiplication followed by an addition.

SEE OR SEARCH THIS CLASS, SUBCLASS:

523,for performing a multiplication followed by addition in arithmetic operations.
  
[List of Patents for class 708 subclass 502]    502Reciprocal:
 This subclass is indented under subclass 495.  Subject matter wherein the operation performed is the determination of the reciprocal.
  
[List of Patents for class 708 subclass 503]    503Multiplication:
 This subclass is indented under subclass 495.  Subject matter wherein the operation performed is multiplication.

SEE OR SEARCH THIS CLASS, SUBCLASS:

7,for hybrid computer multiplication.
620+,for performing a multiplication in digital arithmetical operations.
835+,for analog multiplication.
  
[List of Patents for class 708 subclass 504]    504Division:
 This subclass is indented under subclass 495.  Subject matter wherein the operation performed is division.

SEE OR SEARCH THIS CLASS, SUBCLASS:

7,for hybrid computer division.
650+,for division by digital computer.
844,for division by analog computer.
  
[List of Patents for class 708 subclass 505]    505Addition or subtraction:
 This subclass is indented under subclass 495.  Subject matter wherein the operation performed is addition or subtraction.

SEE OR SEARCH THIS CLASS, SUBCLASS:

670+,for addition/subtraction by digital computer.
  
[List of Patents for class 708 subclass 506]    506Feedback:
 This subclass is indented under subclass 495.  Subject matter wherein the operation is effected by the return of a portion of the output to its input.

SEE OR SEARCH THIS CLASS, SUBCLASS:

632,for feeding back partial product to complete the multiple digit binary multiplication.
  
[List of Patents for class 708 subclass 507]    507Parallel:
 This subclass is indented under subclass 495.  Subject matter wherein the operation is effected by the use of two or more processors running simultaneously.
  
[List of Patents for class 708 subclass 508]    508Pipeline:
 This subclass is indented under subclass 495.  Subject matter wherein the operation is effected by passing the output of one task as input to another until a desired sequence of tasks has been carried out.

SEE OR SEARCH THIS CLASS, SUBCLASS:

233,for multifunctional operation performed in a particular pipeline.
406,for Fourier transformation performed in a particular pipeline.
521,for arithmetical pipeline operation in general.
631,for multiple digit binary multiplication performed in a particular pipeline.
  
[List of Patents for class 708 subclass 509]    509Systolic:
 This subclass is indented under subclass 495.  Subject matter wherein the operation is effected by a specific apparatus using an array of computational elements where data is transferred synchronously between nearest neighbor elements.

SEE OR SEARCH THIS CLASS, SUBCLASS:

407,for a particular systolic array used in a Fourier transform.
522,for a particular systolic array used in an arithmetical operation.

SEE OR SEARCH CLASS:

712, Electrical Computers and Digital Processing Systems: Processing Architectures and Instruction Processing (e.g., Processors),   subclass 19 for systolic array processor architecture.
  
[List of Patents for class 708 subclass 510]    510Microprocessor:
 This subclass is indented under subclass 495.  Subject matter wherein the operation is effected by a microprocessor.

SEE OR SEARCH THIS CLASS, SUBCLASS:

231,for a particular microprocessor used in a multifunctional operation.
303,for a particular microprocessor used in filtering.

SEE OR SEARCH CLASS:

712, Electrical Computers and Digital Processing Systems: Processing Architectures and Instruction Processing ( e.g., Processors) subclasses 32+ for particular microprocessor architecture.
  
[List of Patents for class 708 subclass 511]    511Complex number format:
 This subclass is indented under subclass 495.  Subject matter wherein the numerical digits have a real part and an imaginary part.

SEE OR SEARCH THIS CLASS, SUBCLASS:

622+,for using complex number format in a multiplication operation.
  
[List of Patents for class 708 subclass 512]    512Logarithmic format:
 This subclass is indented under subclass 495.  Subject matter wherein the numerical digits which constitute an operand represented by the exponent to which a base number must be raised to produce the operand.

SEE OR SEARCH THIS CLASS, SUBCLASS:

517,for logarithmic format in arithmetical operations.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 350+ for miscellaneous circuits providing a logarithmic function of an input signal.
  
[List of Patents for class 708 subclass 513]    513Variable length or precision:
 This subclass is indented under subclass 495.  Subject matter wherein the numerical digits which constitute an operand are of selectable length or provide more detail.

SEE OR SEARCH THIS CLASS, SUBCLASS:

518,for variable length in digital arithmetical operations.
  
[List of Patents for class 708 subclass 514]    514Matrix array:
 This subclass is indented under subclass 495.  Subject matter wherein the data is operated on by elements arranged in rows and columns.

SEE OR SEARCH THIS CLASS, SUBCLASS:

520,for a arithmetic matrix array operation in general.
607,for a particular multiplication of matrices.

SEE OR SEARCH CLASS:

712, Electrical Computers and Digital Processing Systems: Processing Architectures and Instruction Processing (e.g., Processors) subclasses 2+ for vector processor architecture.
  
[List of Patents for class 708 subclass 517]    517Logarithmic format:
 This subclass is indented under subclass 490.  Subject matter where an operand is represented by the exponent to which a base number must be raised to produce the operand.

SEE OR SEARCH THIS CLASS, SUBCLASS:

512,for logarithmic format in floating point.
  
[List of Patents for class 708 subclass 518]    518Variable length:
 This subclass is indented under subclass 490.  Subject matter wherein the number of numerical digits that represent numbers are of differing length.

SEE OR SEARCH THIS CLASS, SUBCLASS:

513,for variable length or precision in floating point.
  
[List of Patents for class 708 subclass 519]    519Negative radix:
 This subclass is indented under subclass 490.  Subject matter wherein the numerical digits are represented in negative radix format.
  
[List of Patents for class 708 subclass 520]    520Matrix array:
 This subclass is indented under subclass 490.  Subject matter wherein the data is operated on by elements arranged in rows and columns.
(1) Note. Matrix array processing of multiplication or division per se is classified elsewhere.

SEE OR SEARCH THIS CLASS, SUBCLASS:

514,for a particular matrix array with floating point.
607,for multiplication of matrices.
620+,for multiplication which may incorporate a matrix array.
650+,for division which may incorporate a matrix array.

SEE OR SEARCH CLASS:

712, Electrical Computers and Digital Processing Systems: Processing Architectures and Instruction Processing (e.g., Processors) subclasses 2+ for vector processor architecture.
  
[List of Patents for class 708 subclass 521]    521Pipeline:
 This subclass is indented under subclass 490.  Subject matter wherein the operation is performed in a pipeline by passing the output of one task as input to another until a desired sequence of tasks has been carried out.
(1) Note. Pipeline processing of multiplication or division per se is classified elsewhere.

SEE OR SEARCH THIS CLASS, SUBCLASS:

233,for multifunctional operation performed in a particular pipeline.
406,for Fourier transform performed in a particular pipeline.
508,for floating point performed in a particular pipeline.
620+,for multiplication which may incorporate pipeline processing, particularly
631,for multiple digit binary multiplication performed in a particular pipeline.
650+,for division which may incorporate pipeline processing.
  
[List of Patents for class 708 subclass 522]    522Systolic:
 This subclass is indented under subclass 490.  Subject matter wherein the operation is effected by a specific apparatus using an array of computational elements where data is transferred synchronously between nearest neighbor elements.
(1) Note. Systolic processing of multiplication or division per se is classified elsewhere.

SEE OR SEARCH THIS CLASS, SUBCLASS:

407,for a particular systolic array used in a Fourier transform.
509,for a particular systolic array used in floating point.
620+,for multiplication which may incorporate systolic processing.
650+,for division which may incorporate systolic processing.

SEE OR SEARCH CLASS:

712, Electrical Computers and Digital Processing Systems: Processing Architectures and Instruction Processing ( e.g., Processors) subclass 19 for systolic array processor architecture.
  
[List of Patents for class 708 subclass 523]    523Multiplication followed by addition (i.e., x*y+z):
 This subclass is indented under subclass 490.  Subject matter wherein the operation performed is a multiplication followed by an addition.

SEE OR SEARCH THIS CLASS, SUBCLASS:

501,for performing a multiplication followed by addition with floating point.
  
[List of Patents for class 708 subclass 524]    524Multiple parallel operations:
 This subclass is indented under subclass 490.  Subject matter including two or more operations in which numerical digits are transmitted simultaneously on separate lines.
  
[List of Patents for class 708 subclass 525]    525Status condition/flag generation or use:
 This subclass is indented under subclass 490.  Subject matter where an indicator of the present data processing status is generated or used to select from a plurality of future processing paths.

SEE OR SEARCH THIS CLASS, SUBCLASS:

306,for flag generation or use in a digital filtering finite arithmetic effect environment.
  
[List of Patents for class 708 subclass 530]    530Error detection or correction:
 This subclass is indented under subclass 490.  Subject matter with means identifying a malfunction in the operation of the apparatus or the result produced.

SEE OR SEARCH CLASS:

714, Error Detection/Correction and Fault Detection/Recovery,   appropriate subclass for systems which test for malfunction in nonarithmetical operations.
  
[List of Patents for class 708 subclass 531]    531Parity check:
 This subclass is indented under subclass 530.  Subject matter wherein the error detection or correction utilizes a parity bit.

SEE OR SEARCH CLASS:

340, Communications: Electrical,   subclass 146.2 for detecting error in information content of a group of signals by parity check.
714, Error Detection/Correction and Fault Detection/Recovery,   appropriate subclass for systems which test for malfunction in nonarithmetical operations.
  
[List of Patents for class 708 subclass 532]    532Residue code:
 This subclass is indented under subclass 530.  Subject matter wherein the error detection or correction utilizes a residue code.
(1) Note. The residue is the remainder after dividing a number by a modulus n.

SEE OR SEARCH THIS CLASS, SUBCLASS:

491,for residue number arithmetical operation.

SEE OR SEARCH CLASS:

714, Error Detection/Correction and Fault Detection/Recovery,   subclass 808 for error detection by residue code in nonarithmetic operations.
  
[List of Patents for class 708 subclass 533]    533Sequential repetition:
 This subclass is indented under subclass 530.  Subject matter wherein the error detection or correction utilizes sequential repetition.
  
[List of Patents for class 708 subclass 534]    534Plural parallel devices:
 This subclass is indented under subclass 530.  Subject matter wherein the error detection or correction utilizes plural parallel devices.

SEE OR SEARCH CLASS:

714, Error Detection/ Correction and Fault Detection/ Recovery subclasses 3+ for fault recovery including masking or reconfiguring, per se, in a digital data processing system and subclasses 820+ for plural parallel devices/channels in nonarithmetic operations.
  
[List of Patents for class 708 subclass 540]    540Cathode-ray tube:
 This subclass is indented under subclass 490.  Subject matter wherein the specific apparatus for performing the arithmetic operation utilizes a cathode-ray tube.

SEE OR SEARCH CLASS:

315, Electric Lamp and Discharge Devices: Systems,   subclasses 1+ for cathode ray tube circuits in general.
  
[List of Patents for class 708 subclass 541]    541Contact-making device:
 This subclass is indented under subclass 490.  Subject matter wherein the specific apparatus for performing the arithmetic operation utilizes a contact-making device such as a relay.

SEE OR SEARCH CLASS:

200, Electricity: Circuit Makers and Breakers,   appropriate subclasses for electrical switches, per se.
  
[List of Patents for class 708 subclass 542]    542Radix point control:
 This subclass is indented under subclass 490.  Subject matter for controlling the radix point position relative to the numerical digits, e.g., controlling the position of a decimal point.

SEE OR SEARCH THIS CLASS, SUBCLASS:

498,for overflow or underflow used in floating point.
  
[List of Patents for class 708 subclass 550]    550Compensation for finite word length:
 This subclass is indented under subclass 490.  Subject matter wherein the operation results in a word modification in length due to insufficient representation of using the fixed word length of the arithmetic system.

SEE OR SEARCH THIS CLASS, SUBCLASS:

306,for finite arithmetic effect in digital filtering.
496+,for a particular compensation for finite word length used in a floating point.
  
[List of Patents for class 708 subclass 551]    551Round off or truncation:
 This subclass is indented under subclass 550.  Subject matter wherein the modification is an adjustment of the more significant digits in accordance with some specific rule or a deletion of one or more of the least significant digits.

SEE OR SEARCH THIS CLASS, SUBCLASS:

497,for round off or truncation used in floating point.
  
[List of Patents for class 708 subclass 552]    552Overflow or underflow:
 This subclass is indented under subclass 550.  Subject matter wherein the modification is necessary because the word is either too large or too small to be represented using the fixed word length.

SEE OR SEARCH THIS CLASS, SUBCLASS:

498,for overflow or underflow in floating point processing.
  
[List of Patents for class 708 subclass 553]    553Prediction:
 This subclass is indented under subclass 552.  Subject matter wherein the overflow or underflow is forecasted before the operation is performed.
  
[List of Patents for class 708 subclass 603]    603Sum of products generation:
 This subclass is indented under subclass 490.  Subject matter for producing and adding together a plurality of operand product terms.

SEE OR SEARCH THIS CLASS, SUBCLASS:

319,for similar processing in a transversal filter environment.
420,for similar processing in digital convolution.
  
[List of Patents for class 708 subclass 604]    604All four basic functions:
 This subclass is indented under subclass 490.  Subject matter wherein the computer has the capability of performing the functions of multiplication, division, addition and subtraction.
  
[List of Patents for class 708 subclass 605]    605Evaluation of root:
 This subclass is indented under subclass 490.  Subject matter wherein the arithmetic operation performed is the determination of roots.

SEE OR SEARCH THIS CLASS, SUBCLASS:

807,for evaluation of root by analog computer.
  
[List of Patents for class 708 subclass 606]    606Evaluation of powers:
 This subclass is indented under subclass 490.  Subject matter wherein the arithmetic operation performed is the raising of numbers to powers.

SEE OR SEARCH THIS CLASS, SUBCLASS:

808,for evaluation of powers by analog computer.
  
[List of Patents for class 708 subclass 607]    607Multiplication of matrices:
 This subclass is indented under subclass 490.  Subject matter wherein multiplication is performed on plural sets of data arranged in rows and columns.

SEE OR SEARCH THIS CLASS, SUBCLASS:

514,for a particular floating point matrix array.
520,for a particular arithmetic operation matrix array.

SEE OR SEARCH CLASS:

712, Electrical Computers and Digital Processing Systems: Processing Architectures and Instruction Processing (e.g., Processors) subclasses 2+ for vector processor architecture.
  
[List of Patents for class 708 subclass 620]    620Multiplication:
 This subclass is indented under subclass 490.  Subject matter wherein the arithmetic operation performed is multiplication.

SEE OR SEARCH THIS CLASS, SUBCLASS:

7,for multiplication by hybrid computer.
503,for performing multiplication in floating point.
835,for multiplication by analog computer.
  
[List of Patents for class 708 subclass 622]    622Complex number format:
 This subclass is indented under subclass 620.  Subject matter wherein the numerical digits have a real part and an imaginary part.

SEE OR SEARCH THIS CLASS, SUBCLASS:

511,for using complex number format in floating point.
  
[List of Patents for class 708 subclass 623]    623Decimal:
 This subclass is indented under subclass 620.  Subject matter wherein the numerical digits are of radix ten.

SEE OR SEARCH THIS CLASS, SUBCLASS:

624,for coded decimal multiplication.
  
[List of Patents for class 708 subclass 624]    624Coded decimal:
 This subclass is indented under subclass 620.  Subject matter wherein the numerical digits are of radix ten expressed in terms of another lesser radix.

SEE OR SEARCH THIS CLASS, SUBCLASS:

623,for decimal multiplication.
  
[List of Patents for class 708 subclass 625]    625Binary:
 This subclass is indented under subclass 620.  Subject matter wherein the numerical digits are of radix two.

SEE OR SEARCH THIS CLASS, SUBCLASS:

624,for arithmetic operations on digits of radix two within a denomination.
654,for division by multiplication by reciprocal.
  
[List of Patents for class 708 subclass 626]    626Sum of cross products:
 This subclass is indented under subclass 625.  Subject matter wherein the multiplication is effected by the sum of cross products technique.
  
[List of Patents for class 708 subclass 627]    627Repeated addition:
 This subclass is indented under subclass 625.  Subject matter wherein the multiplication is effected by the repeated addition technique.
  
[List of Patents for class 708 subclass 628]    628Multiple digit:
 This subclass is indented under subclass 627.  Subject matter wherein at a given instant of time a plurality of multiplier digits control the repeated addition operation.
  
[List of Patents for class 708 subclass 629]    629Carry-save adders (i.e., CSAs):
 This subclass is indented under subclass 628.  Subject matter including an array of carry-save adders to perform the multiplication.

SEE OR SEARCH THIS CLASS, SUBCLASS:

708,for parallel carry-save adders in binary addition/subtraction.
  
[List of Patents for class 708 subclass 630]    630Array adders:
 This subclass is indented under subclass 628.  Subject matter including an array of circuits or integrated circuits that sum the amplitude of two input signals to perform the multiplication.
  
[List of Patents for class 708 subclass 631]    631Pipeline:
 This subclass is indented under subclass 628.  Subject matter including a specific apparatus passing the output of one task as input to another until a desired sequence of tasks has been carried out.

SEE OR SEARCH THIS CLASS, SUBCLASS:

233,for multifunctional operation performed in a particular pipeline.
406,for Fourier transformation performed in a particular pipeline.
508,for floating point performed in a particular pipeline.
521,for arithmetical pipeline operation in general.
  
[List of Patents for class 708 subclass 632]    632Feedback:
 This subclass is indented under subclass 628.  Subject matter including means which involves feeding back a partial product as an input to complete the multiplication.

SEE OR SEARCH THIS CLASS, SUBCLASS:

506,for feeding back a portion of the output to its input in floating point.
  
[List of Patents for class 708 subclass 650]    650Division:
 This subclass is indented under subclass 490.  Subject matter wherein the arithmetic operation performed is division.

SEE OR SEARCH THIS CLASS, SUBCLASS:

7,for division by hybrid computer.
504,for floating point division.
844,for division by analog computer.
  
[List of Patents for class 708 subclass 651]    651Decimal:
 This subclass is indented under subclass 650.  Subject matter wherein the numerical digits are of radix ten.

SEE OR SEARCH THIS CLASS, SUBCLASS:

623,for decimal multiplication.
652,for coded decimal division.
  
[List of Patents for class 708 subclass 652]    652Coded decimal:
 This subclass is indented under subclass 650.  Subject matter wherein the numerical digits are of radix ten expressed in terms of another lesser radix.

SEE OR SEARCH THIS CLASS, SUBCLASS:

624,for coded decimal multiplication.
651,for decimal division.
  
[List of Patents for class 708 subclass 653]    653Binary:
 This subclass is indented under subclass 650.  Subject matter wherein the numerical digits are of radix two.

SEE OR SEARCH THIS CLASS, SUBCLASS:

625+,for binary multiplication.
  
[List of Patents for class 708 subclass 654]    654Multiplication by reciprocal:
 This subclass is indented under subclass 653.  Subject matter wherein the division is effected by multiplying the dividend by the reciprocal of the divisor.

SEE OR SEARCH THIS CLASS, SUBCLASS:

625+,for binary multiplication in general.
  
[List of Patents for class 708 subclass 655]    655Repeated subtraction:
 This subclass is indented under subclass 653.  Subject matter wherein the division is effected by the repeated subtraction technique.
  
[List of Patents for class 708 subclass 656]    656Multiples of divisor:
 This subclass is indented under subclass 655.  Subject matter wherein multiples of the divisor are used in the repeated subtraction operation.
  
[List of Patents for class 708 subclass 670]    670Addition/subtraction:
 This subclass is indented under subclass 490.  Subject matter wherein the arithmetic operation performed is addition or subtraction.

SEE OR SEARCH THIS CLASS, SUBCLASS:

505,for floating point addition or subtraction.

SEE OR SEARCH CLASS:

326, Electronic Digital Logic Circuitry,   subclass 53 for an electronic digital logic type quarter or half-adder.
327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 355+ for miscellaneous adding or subtracting circuits.
  
[List of Patents for class 708 subclass 671]    671Comparison:
 This subclass is indented under subclass 670.  Subject matter for comparing by determining the mathematical magnitude of the difference between two numbers.

SEE OR SEARCH THIS CLASS, SUBCLASS:

207,for determination of maximum of" or minimum of" a series of numbers by comparison.

SEE OR SEARCH CLASS:

340, Communications: Electrical,   subclass 146.2 for digital comparator system.
  
[List of Patents for class 708 subclass 672]    672Incrementation/decrementation:
 This subclass is indented under subclass 670.  Subject matter for incrementation or decrementation which is performed by changing by one the value of the numerical digit in the least significant digit position.

SEE OR SEARCH CLASS:

377, Electrical Pulse Counters, Pulse Dividers, or Shift Registers: Circuits and Systems,   for electrical pulse counters and counting systems.
  
[List of Patents for class 708 subclass 673]    673Radix correction:
 This subclass is indented under subclass 670.  Subject matter for correction for a change in radix.
(1) Note. For example, binary coded decimal with 6" correction.

SEE OR SEARCH THIS CLASS, SUBCLASS:

683,for a device operating in coded decimal fashion that does not require radix correction.
  
[List of Patents for class 708 subclass 674]    674Serial:
 This subclass is indented under subclass 673.  Subject matter wherein the radix correction is performed by operation on the numerical digits in a serial manner.
  
[List of Patents for class 708 subclass 675]    675Signal amplitude:
 This subclass is indented under subclass 670.  Subject matter wherein the addition or subtraction is performed by summing signal amplitudes.
  
[List of Patents for class 708 subclass 676]    676Microwave:
 This subclass is indented under subclass 670.  Subject matter wherein the addition or subtraction is performed utilizing a microwave device.
  
[List of Patents for class 708 subclass 677]    677Cryogenic:
 This subclass is indented under subclass 670.  Subject matter wherein the addition or subtraction is performed utilizing a cryogenic device.

SEE OR SEARCH CLASS:

505, Superconductor Technology: Apparatus, Material, Process,   appropriate subclasses for superconductor technology.
  
[List of Patents for class 708 subclass 678]    678By electronic tube:
 This subclass is indented under subclass 670.  Subject matter wherein the addition or subtraction is performed utilizing an electronic tube.
  
[List of Patents for class 708 subclass 679]    679Magnetic:
 This subclass is indented under subclass 670.  Subject matter wherein the addition or subtraction is performed utilizing a magnetic device.
  
[List of Patents for class 708 subclass 680]    680Decimal:
 This subclass is indented under subclass 670.  Subject matter wherein the numerical digits are of radix ten.

SEE OR SEARCH THIS CLASS, SUBCLASS:

683+,for coded decimal addition/subtraction.
  
[List of Patents for class 708 subclass 681]    681Serial:
 This subclass is indented under subclass 680.  Subject matter wherein the numerical digits are operated on in a serial manner.
  
[List of Patents for class 708 subclass 682]    682Parallel:
 This subclass is indented under subclass 680.  Subject matter wherein the numerical digits are operated on in a parallel manner.
  
[List of Patents for class 708 subclass 683]    683Coded decimal:
 This subclass is indented under subclass 670.  Subject matter wherein the numerical digits are of radix ten expressed in terms of another lesser radix.

SEE OR SEARCH THIS CLASS, SUBCLASS:

673,for a device which accomplishes radix correction.
680,for decimal addition/subtraction.
  
[List of Patents for class 708 subclass 684]    684Serial:
 This subclass is indented under subclass 683.  Subject matter wherein the numerical digits are operated on in a serial manner.
  
[List of Patents for class 708 subclass 685]    685Parallel:
 This subclass is indented under subclass 683.  Subject matter wherein the numerical digits are operated on in a parallel manner.
  
[List of Patents for class 708 subclass 700]    700Binary:
 This subclass is indented under subclass 670.  Subject matter wherein the numerical digits are of radix two.
  
[List of Patents for class 708 subclass 701]    701Bipolar junction transistor only or combined with Field-Effect Transistor:
 This subclass is indented under subclass 700.  Subject matter including a transistor that uses both negative and positive charge carriers or combined with a transistor in which current carriers (holes or electrons) are injected at one terminal (the source) and pass to another (the drain) through a channel of semiconductor material whose resistivity depends mainly on the extent to which it is penetrated by a depletion region.
  
[List of Patents for class 708 subclass 702]    702Field-Effect Transistor (FET):
 This subclass is indented under subclass 700.  Subject matter including a transistor in which current carriers (holes or electrons) are injected at one terminal (the source) and pass to another (the drain) through a channel of semiconductor material whose resistivity depends mainly on the extent to which it is penetrated by a depletion region.
  
[List of Patents for class 708 subclass 703]    703Gate function level:
 This subclass is indented under subclass 700.  Subject matter including means to show a gate functional level or combined with a transistor.
  
[List of Patents for class 708 subclass 704]    704For precharging (e.g., Manchester, etc.):
 This subclass is indented under subclass 700.  Subject matter using clock signal for precharging a field-effect transistor.
  
[List of Patents for class 708 subclass 705]    705Serial:
 This subclass is indented under subclass 700.  Subject matter wherein the numerical digits are operated on in a serial manner.
  
[List of Patents for class 708 subclass 706]    706Parallel:
 This subclass is indented under subclass 700.  Subject matter wherein the numerical digits are operated upon in a simultaneous manner.

SEE OR SEARCH THIS CLASS, SUBCLASS:

507,for providing the digits in a parallel manner in floating point.
  
[List of Patents for class 708 subclass 707]    707Carry-ripple:
 This subclass is indented under subclass 706.  Subject matter wherein a carry signal ripples through each digit.

SEE OR SEARCH THIS CLASS, SUBCLASS:

711,for block of carry-out signal.
  
[List of Patents for class 708 subclass 708]    708Carry-save adders:
 This subclass is indented under subclass 706.  Subject matter including more than one carry-save adder for performing the addition.

SEE OR SEARCH THIS CLASS, SUBCLASS:

629,for carry-save adders in binary multiplication.
  
[List of Patents for class 708 subclass 709]    709Adding more than two numbers:
 This subclass is indented under subclass 706.  Subject matter wherein at least three numbers are added.
  
[List of Patents for class 708 subclass 710]    710Carry look-ahead:
 This subclass is indented under subclass 706.  Subject matter wherein the addition or subtraction is performed by a circuit which predicts the final carry from propagate and generate signals supplied by partial adders.

SEE OR SEARCH THIS CLASS, SUBCLASS:

712,for the carry-out signals of the blocks.
  
[List of Patents for class 708 subclass 711]    711Slice block having block ripple:
 This subclass is indented under subclass 710.  Subject matter wherein carry-out signal of a block ripples through the next block.

SEE OR SEARCH THIS CLASS, SUBCLASS:

707,for the carry signal ripple through each digit.
  
[List of Patents for class 708 subclass 712]    712Slice block having block look-ahead:
 This subclass is indented under subclass 710.  Subject matter wherein the carry signals of the blocks look-ahead.
  
[List of Patents for class 708 subclass 713]    713Tree structured logic blocks:
 This subclass is indented under subclass 710.  Subject matter including more than one logic block containing one or more nodes that are linked together in a hierarchical fashion.
  
[List of Patents for class 708 subclass 714]    714Conditional sums:
 This subclass is indented under subclass 706.  Subject matter wherein the addition or subtraction is performed utilizing conditional sums.
  
[List of Patents for class 708 subclass 800]    800ELECTRICAL ANALOG CALCULATING COMPUTER:
 This subclass is indented under the class definition.  Subject matter which includes devices for performing calculation operations upon electrical signals, such as current or voltage, which are continuously varying representations of physical quantities and which are some function of the quantities such as direct proportion, inverse proportion or square law relationship.
(1) Note. The limited logic operations include comparison or selection, for example.
(2) Note. The continuously varying representations, for example, may be frequency or pulse width.
(3) Note. Signals wherein the varying representation is pulse rate are included with subject matter under Electric Digital Calculating Computer".
(4) Note. Examples of the physical quantities above are temperature, pressure, angular position, or weight numerical values.

SEE OR SEARCH THIS CLASS, SUBCLASS:

1+,for electrical hybrid calculating computers.
100+,for electrical digital calculating computers.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   appropriate subclasses for miscellaneous active device analog circuits.
  
[List of Patents for class 708 subclass 801]    801Particular function performed:
 This subclass is indented under subclass 800.  Subject matter directed to a particular function performed by an analog computer or subcombination thereof in making a computation.
(1) Note. For classification herein the function performed must be significantly claimed in making a computation.

SEE OR SEARCH CLASS:

706, Data Processing: Artificial Intelligence,   subclasses 1+ for fuzzy logic hardware and subclasses 15+ for neural networks.
  
[List of Patents for class 708 subclass 802]    802Evaluation of equation:
 This subclass is indented under subclass 801.  Subject matter for obtaining the solution to a mathematical problem.
(1) Note. The mathematical problem may be expressed as equations, conditions, etc., and the solution may be a value or set of values or the value which meets some objective criteria.
(2) Note. This subclass includes subject matter which utilized an analog signal as a computing component and in which the computing component is employed more than once to determine a mathematical solution by successive steps.
(3) Note. This subclass does not include subject matter classifiable as specific types of problems or operations found below.
  
[List of Patents for class 708 subclass 803]    803Simultaneous:
 This subclass is indented under subclass 802.  Subject matter for the solution of simultaneous equations or conditions.
(1) Note. Linear programming problems are included herein.

SEE OR SEARCH CLASS:

705, Data Processing: Financial, Business Practice, Management, or Cost/Price Determination,   subclasses 7.11 through 7.42for operations research processing.
  
[List of Patents for class 708 subclass 804]    804Differential (e.g., differential analyzer):
 This subclass is indented under subclass 802.  Subject matter wherein the equations evaluated are differential equations.

SEE OR SEARCH THIS CLASS, SUBCLASS:

102,for differential analyzers of the digital type.
  
[List of Patents for class 708 subclass 805]    805Averaging:
 This subclass is indented under subclass 801.  Subject matter wherein the function performed is determining an average amplitude for a signal.

SEE OR SEARCH THIS CLASS, SUBCLASS:

445,for averaging by means of a digital calculating computer.

SEE OR SEARCH CLASS:

702, Data Processing: Measuring, Calibrating, or Testing,   subclass 194 for measured signal noise suppression by averaging.
  
[List of Patents for class 708 subclass 806]    806Variance or standard deviation determination:
 This subclass is indented under subclass 801.  Subject matter wherein the function performed is determining variance or standard deviation.

SEE OR SEARCH CLASS:

702, Data Processing: Measuring, Calibrating, or Testing,   subclasses 179+ for statistical measurement.
  
[List of Patents for class 708 subclass 807]    807Evaluation of root (e.g., square root):
 This subclass is indented under subclass 801.  Subject matter wherein the function performed is root evaluation.

SEE OR SEARCH THIS CLASS, SUBCLASS:

605,for evaluation of root by digital computer.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 346+ for miscellaneous circuits in which an output signal is exponentially related to an input signal.
  
[List of Patents for class 708 subclass 808]    808Evaluation of powers:
 This subclass is indented under subclass 801.  Subject matter wherein the function performed is the evaluation of the powers of an input signal.

SEE OR SEARCH THIS CLASS, SUBCLASS:

606,for evaluation of powers by digital computer.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 346+ for miscellaneous circuits in which an output signal is exponentially related to an input signal.
  
[List of Patents for class 708 subclass 809]    809Coordinate conversion or vector resolver:
 This subclass is indented under subclass 801.  Subject matter wherein the computer converts from one coordinate system to another, such as from rectangular to polar or resolving a vector into its coordinate values.

SEE OR SEARCH THIS CLASS, SUBCLASS:

441,for a vector resolver using digital computer.
442,for a coordinate conversion using digital computer.

SEE OR SEARCH CLASS:

235, Registers,   subclass 61 for coordinate conversion by mechanical computers and subclass 410 for coordinate conversion in ordnance computers.
318, Electricity: Motive Power Systems,   subclass 605 for synchros or resolvers used in analog comparison techniques for digital or numerical positional servo systems and subclass 661 for resolver type differential transformer systems used as a particular position measuring instrument for a positional servo error detecting means.
  
[List of Patents for class 708 subclass 810]    810Electromechanical:
 This subclass is indented under subclass 809.  Subject matter wherein the function is performed utilizing an electromechanical device.
  
[List of Patents for class 708 subclass 811]    811Evaluation of trigonometric function:
 This subclass is indented under subclass 801.  Subject matter wherein the function performed is processing of a signal to either determine a trigonometric relationship or to operate on a signal in accordance with a trigonometric relationship.
(1) Note. Generation of a waveform having trigonometric relationship(s) is included herein.

SEE OR SEARCH THIS CLASS, SUBCLASS:

440,for evaluation of trigonometric function by digital computer.
  
[List of Patents for class 708 subclass 812]    812Single triangle:
 This subclass is indented under subclass 811.  Subject matter which solves for an unknown parameter of a plane triangle.
  
[List of Patents for class 708 subclass 813]    813Correlation or convolution:
 This subclass is indented under subclass 801.  Subject matter for evaluating cross-correlation, auto-correlation, cross-convolution or auto-convolution functions.

SEE OR SEARCH THIS CLASS, SUBCLASS:

420+,for convolution by digital computer.
422+,for correlation by digital computer.

SEE OR SEARCH CLASS:

324, Electricity: Measuring and Testing,   subclasses 76.12+ and indented subclass for correlators used in frequency spectrum analyzer systems.
342, Communications: Directive Radio Wave Systems and Devices (e.g., Radar, Radio Navigation),   subclasses 378+ for directive radio wave communications systems using correlation techniques.
367, Communications, Electrical: Acoustic Wave Systems and Devices,   subclasses 38+ for correlators used in geophysical communications systems.
  
[List of Patents for class 708 subclass 814]    814Of multidimensional data:
 This subclass is indented under subclass 813.  Subject matter wherein the correlation or convolution is of multidimensional data.

SEE OR SEARCH THIS CLASS, SUBCLASS:

424,for digital correlation of multidimensional data.

SEE OR SEARCH CLASS:

342, Communications: Directive Radio Wave Systems and Devices (e.g., Radar, Radio Navigation),   subclass 5 for correlation functions employed in radar systems with map matching.
  
[List of Patents for class 708 subclass 815]    815Acoustic:
 This subclass is indented under subclass 813.  Subject matter utilizing compressional wave propagation along or through a medium other than a light modulator.

SEE OR SEARCH THIS CLASS, SUBCLASS:

816,for light modulation using compressional waves.
  
[List of Patents for class 708 subclass 816]    816Optical:
 This subclass is indented under subclass 813.  Subject matter utilizing optical devices and producing an electrical output.

SEE OR SEARCH CLASS:

706, Data Processing: Artificial Intelligence,   subclass 40 for optical neural networks.
  
[List of Patents for class 708 subclass 817]    817Magnetic or electromagnetic:
 This subclass is indented under subclass 813.  Subject matter utilizing a magnetic or electromagnetic device.
  
[List of Patents for class 708 subclass 818]    818Having tapped delay line:
 This subclass is indented under subclass 813.  Subject matter utilizing a tapped delay line.

SEE OR SEARCH THIS CLASS, SUBCLASS:

301,for related structure in digital filtering.
425,for correlation using tapped delay line.
  
[List of Patents for class 708 subclass 819]    819Filtering:
 This subclass is indented under subclass 801.  Subject matter utilized for filtering electrical signals by computation.

SEE OR SEARCH THIS CLASS, SUBCLASS:

300+,for digital filtering.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 552+ for miscellaneous unwanted signal suppression utilizing an active filter circuit not performing an arithmetic calculation.
333, Wave Transmission Lines and Networks,   subclass 18 for filters used in automatically controlled equalizer or delay networks; subclass 28 for analog filters in equalizer coupling networks and subclasses 167+ for analog type transversal filter coupling networks.
375, Pulse or Digital Communications,   subclasses 229+ and 285 for filtering techniques used in distortion or noise prevention or correction means for modulated carrier wave communication systems.
455, Telecommunications,   subclass 307 for filtering in a radio receiver.
702, Data Processing: Measuring, Calibrating, or Testing,   subclasses 191+ for measured signal noise suppression.
  
[List of Patents for class 708 subclass 820.]    820.Transform:
 This subclass is indented under subclass 801.  Subject matter wherein the function performed is transforming a given representation of a data signal to another representation without loss of information by an orthogonal transformation.

SEE OR SEARCH THIS CLASS, SUBCLASS:

5,for transform by hybrid computer.
400+,for transform by digital calculating computer.
  
[List of Patents for class 708 subclass 821]    821Fourier:
 This subclass is indented under subclass 820.  Subject matter wherein the transformation is from the time or space domain to the frequency domain or the converse.

SEE OR SEARCH THIS CLASS, SUBCLASS:

403+,for Fourier transform by digital calculating computer.
  
[List of Patents for class 708 subclass 822]    822Differentiation:
 This subclass is indented under subclass 801.  Subject matter wherein the function performed is differentiation of at least one of a plurality of input signals.

SEE OR SEARCH THIS CLASS, SUBCLASS:

443,for differentiation by a digital computer.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclass 335 for a miscellaneous circuit providing the derivative of an input signal without computation.
  
[List of Patents for class 708 subclass 823]    823Integrator:
 This subclass is indented under subclass 801.  Subject matter wherein the function performed is integration of at least one of a plurality of input signals.

SEE OR SEARCH THIS CLASS, SUBCLASS:

444,for integration by a digital computer.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 336+ for a miscellaneous circuit providing the integral of an input signal without computation.
  
[List of Patents for class 708 subclass 824]    824Plural integration:
 This subclass is indented under subclass 823.  Subject matter wherein the function performed is plural integration.
  
[List of Patents for class 708 subclass 825]    825Plural mode (e.g., plural scale):
 This subclass is indented under subclass 823.  Subject matter wherein the apparatus is capable of operating in plural modes or scales.
  
[List of Patents for class 708 subclass 826]    826Reset:
 This subclass is indented under subclass 823.  Subject matter wherein the integration operation is reset when the output meets a predetermined condition.
  
[List of Patents for class 708 subclass 827]    827Drift correction:
 This subclass is indented under subclass 823.  Subject matter additionally including the function of drift correction.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclass 307 for miscellaneous baseline or DC offset correction circuits.
  
[List of Patents for class 708 subclass 828]    828Having simultaneous calculation of another function:
 This subclass is indented under subclass 823.  Subject matter where the input signal on which integration is performed is simultaneously subject to a calculation function other than integration and the output is a function of both.
  
[List of Patents for class 708 subclass 829]    829Having a voltage to frequency converter:
 This subclass is indented under subclass 823.  Subject matter utilizing a voltage to frequency converter.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclass 101 for conversion per se of input current or voltage to output frequency.
  
[List of Patents for class 708 subclass 830]    830Electromechanical:
 This subclass is indented under subclass 823.  Subject matter utilizing an electromechanical device.
  
[List of Patents for class 708 subclass 831]    831Electro-optical:
 This subclass is indented under subclass 823.  Subject matter utilizing an electro-optical device.
  
[List of Patents for class 708 subclass 832]    832Magnetic or electromagnetic:
 This subclass is indented under subclass 823.  Subject matter utilizing a magnetic or electromagnetic device.
  
[List of Patents for class 708 subclass 833]    833Amplifier with additional feedback loop:
 This subclass is indented under subclass 823.  Subject matter utilizing an integrating amplifier with an additional feedback loop.

SEE OR SEARCH CLASS:

330, Amplifiers,   subclasses 75+ for amplifier circuits with signal feedback.
  
[List of Patents for class 708 subclass 834]    834Additional R/C feedback loop:
 This subclass is indented under subclass 833.  Subject matter including a resistance or capacitance in the additional feedback loop.
  
[List of Patents for class 708 subclass 835]    835Multiplication:
 This subclass is indented under subclass 801.  Subject matter wherein the function performed is multiplication.

SEE OR SEARCH THIS CLASS, SUBCLASS:

7,for hybrid computer multiplication.
620+,for digital multiplication in general.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 356+ for a miscellaneous circuit providing the product of a plurality of inputs.
  
[List of Patents for class 708 subclass 836]    836Time division:
 This subclass is indented under subclass 835.  Subject matter wherein one input variable is used to control the mark-to-space ratio and the other variable is used to control the amplitude of a repetitive rectangular wave.
(1) Note. Each variable can be represented by current or voltage and the output voltage, proportional to the area of the pulse voltage-time curve, represents the product of the input variables.
  
[List of Patents for class 708 subclass 837]    837Quarter-square:
 This subclass is indented under subclass 835.  Subject matter wherein the product produced pertains to an analog multiplier whose operation is based upon the identity xy = (1/4) (x+y) 2 - (1/4) (x-y) 2.
  
[List of Patents for class 708 subclass 838]    838Having charging or discharging of energy storage device:
 This subclass is indented under subclass 835.  Subject matter wherein the multiplication function is performed by charging or discharging of an energy storage device.

SEE OR SEARCH CLASS:

320, Electricity: Battery or Capacitor Charging or Discharging,   subclass 1 or 2+ for a capacitor or battery charging or discharging circuit.
327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   appropriate subclasses for miscellaneous circuits utilizing the charging or discharging of an energy storage device.
  
[List of Patents for class 708 subclass 839]    839Photomultiplier:
 This subclass is indented under subclass 835.  Subject matter wherein the multiplication function is performed utilizing photomultipliers.

SEE OR SEARCH CLASS:

250, Radiant Energy,   subclasses 206+ for photocell controlled circuits in general.
  
[List of Patents for class 708 subclass 840]    840Electromagnetic:
 This subclass is indented under subclass 835.  Subject matter wherein the multiplication function is performed utilizing an electromagnetic device.
  
[List of Patents for class 708 subclass 841]    841Hall effect:
 This subclass is indented under subclass 840.  Subject matter utilizing the Hall effect principle.

SEE OR SEARCH CLASS:

323, Electricity: Power Supply or Regulation Systems,   subclasses 294 and 368 for resistor-type impedance systems which operate under Hall effect principles.
324, Electricity: Measuring and Testing,   subclass 207.2 for magnetic measuring using the Hall effect.
327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclass 511 for miscellaneous Hall effect circuits.
  
[List of Patents for class 708 subclass 842]    842Electromechanical (e.g., servo-multiplier):
 This subclass is indented under subclass 835.  Subject matter wherein the multiplication function is performed utilizing an electromechanical device.
  
[List of Patents for class 708 subclass 843]    843Having alternative division:
 This subclass is indented under subclass 835.  Subject matter wherein the function performed is multiplication of two or more inputs and wherein a division is performed as an alternative function.
  
[List of Patents for class 708 subclass 844]    844Division:
 This subclass is indented under subclass 801.  Subject matter wherein the function performed is division.

SEE OR SEARCH THIS CLASS, SUBCLASS:

650+,for division by digital computer in general.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclass 360 for miscellaneous circuits where the output is a quotient of a plurality of inputs.
  
[List of Patents for class 708 subclass 845]    845Function generation:
 This subclass is indented under subclass 801.  Subject matter wherein the wave shape of at least one analog signal representing a desired function is generated by mathematical operation or a signal is generated as a part of a mathematical operation representing a desired function of at least one variable input parameter.
(1) Note. This and the indented subclasses include waveform synthesizers of the analog type wherein the waveform is internally generated.
(2) Note. Trigonometric waveform generation is excluded.

SEE OR SEARCH THIS CLASS, SUBCLASS:

8+,and 270+, for electrical hybrid or electrical digital computers which perform the function of function generation.
811,for evaluation or generation of trigonometric functions.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 100+ for miscellaneous signal converting, shaping, or generating circuits and subclasses 334+ for miscellaneous circuits providing a function of one or more input signals.
  
[List of Patents for class 708 subclass 846]    846Piece-wise linear synthesis:
 This subclass is indented under subclass 845.  Subject matter wherein the desired function is approximated by a series of segments of straight lines.

SEE OR SEARCH THIS CLASS, SUBCLASS:

9,for a hybrid computer performing piece-wise linear synthesis.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 334+ for a miscellaneous circuit providing a piece-wise approximation to a desired input to output function.
  
[List of Patents for class 708 subclass 847]    847Interpolation/extrapolation:
 This subclass is indented under subclass 846.  Subject matter including determining or estimating a value or values between two or more known predetermined points or by continuing the trend established between two or more known points.

SEE OR SEARCH THIS CLASS, SUBCLASS:

290,for interpolation/extrapolation by digital computer.
  
[List of Patents for class 708 subclass 848]    848Diode breakpoint:
 This subclass is indented under subclass 846.  Subject matter wherein the function is performed by a network or networks of resistors and diodes in which the diodes begin to conduct at different values (breakpoints) of an input signal.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 583+ for miscellaneous diode circuits.
  
[List of Patents for class 708 subclass 849]    849Cathode-ray tube:
 This subclass is indented under subclass 845.  Subject matter wherein sensing a pattern within or external to the envelope of a cathode-ray tube produces a function signal.

SEE OR SEARCH THIS CLASS, SUBCLASS:

540,for a cathode ray tube used in digital arithmetical operation.

SEE OR SEARCH CLASS:

340, Communications: Electrical,   subclass 324 for multiple variation cathode ray display electrical communication systems.
  
[List of Patents for class 708 subclass 850]    850Two or more variables:
 This subclass is indented under subclass 845.  Subject matter wherein the signal represents two or more variables.
  
[List of Patents for class 708 subclass 851]    851Logarithmic/exponential:
 This subclass is indented under subclass 845.  Subject matter wherein the particular generated function is logarithmic/exponential.

SEE OR SEARCH THIS CLASS, SUBCLASS:

277,for logarithmic/exponential function generation by digital computer.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 350+ for miscellaneous circuits providing a logarithmic function of an input signal.
  
[List of Patents for class 708 subclass 852]    852Triangular, sawtooth, or ramp:
 This subclass is indented under subclass 845.  Subject matter wherein the particular generated function is of the triangular, sawtooth or ramp type.

SEE OR SEARCH THIS CLASS, SUBCLASS:

274,for a linear function generator by digital computer.

SEE OR SEARCH CLASS:

327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,   subclasses 131+ for miscellaneous circuits providing a sawtooth or ramp type waveform.
  
[List of Patents for class 708 subclass 853]    853Hyperbolic:
 This subclass is indented under subclass 845.  Subject matter wherein the particular generated function is hyperbolic.
  
[List of Patents for class 708 subclass 854]    854Electromechanical:
 This subclass is indented under subclass 845.  Subject matter wherein the function is performed utilizing an electromechanical device.
  
United States Patent and Trademark Office