2183 Making a Prima Facie Case of Equivalence [R-01.2024]

[Editor Note: This MPEP section is applicable regardless of whether an application is examined under the AIA or under pre-AIA law. For applications subject to the first inventor to file (FITF) provisions of the AIA, the relevant time is "before the effective filing date of the claimed invention". For applications subject to pre-AIA 35 U.S.C. 102, the relevant time is "at the time of the invention". See MPEP § 2150 et seq. Many of the court decisions discussed in this section involved applications or patents subject to pre-AIA 35 U.S.C. 102. These court decisions may be applicable to applications and patents subject to AIA 35 U.S.C. 102 but the relevant time is before the effective filing date of the claimed invention and not at the time of the invention.]

If the examiner finds that a prior art element

• (A) performs the function specified in the claim,
• (B) is not excluded by any explicit definition provided in the specification for an equivalent, and
• (C) is an equivalent of the means- (or step-) plus-function limitation,

the examiner should provide an explanation and rationale in the Office action as to why the prior art element is an equivalent. See In re Bond, 910 F.2d 831, 833, 15 USPQ2d 1566, 1568 (Fed. Cir. 1990) ("The disclosed and prior art structures are not identical, but the claim may nonetheless be anticipated. … However, the Board made no finding that the delay means of claim 1 and that embodied in the Curtis device are structurally equivalent. Accordingly, its decision as to the anticipation of claim 1 is deficient and must be vacated.”)

Factors that will support a conclusion that the prior art element is an equivalent are:

• (A) The prior art element performs the identical function specified in the claim in substantially the same way, and produces substantially the same results as the corresponding element disclosed in the specification. Kemco Sales, Inc. v. Control Papers Co., 208 F.3d 1352, 1364, 54 USPQ2d 1308, 1315 (Fed. Cir. 2000) (An internal adhesive sealing the inner surfaces of an envelope pocket was not held to be equivalent to an adhesive on a flap which attached to the outside of the pocket. Both the claimed invention and the accused device performed the same function of closing the envelope, but the accused device performed the function in a substantially different way (by an internal adhesive on the inside of the pocket) with a substantially different result (the adhesive attached the inner surfaces of both sides of the pocket)); Odetics Inc. v. Storage Tech. Corp., 185 F.3d 1259, 1267, 51 USPQ2d 1225, 1229-30 (Fed. Cir. 1999); Lockheed Aircraft Corp. v. United States, 193 USPQ 449, 461 (Ct. Cl. 1977). The concepts of equivalents as set forth in Graver Tank & Mfg. Co. v. Linde Air Products, 339 U.S. 605, 85 USPQ 328 (1950) are relevant to any “equivalents” determination. Polumbo v. Don-Joy Co., 762 F.2d 969, 975 n.4, 226 USPQ 5, 8-9 n.4 (Fed. Cir. 1985).
• (B) A person of ordinary skill in the art would have recognized the interchangeability of the element shown in the prior art for the corresponding element disclosed in the specification. Caterpillar Inc. v. Deere & Co., 224 F.3d 1374, 56 USPQ2d 1305 (Fed. Cir. 2000); Al-Site Corp. v. VSI Int’ l, Inc., 174 F.3d 1308, 1316, 50 USPQ2d 1161, 1165 (Fed. Cir. 1999); Chiuminatta Concrete Concepts, Inc. v. Cardinal Indus. Inc., 145 F.3d 1303, 1309, 46 USPQ2d 1752, 1757 (Fed. Cir. 1998); Lockheed Aircraft Corp. v. United States, 193 USPQ 449, 461 (Ct. Cl. 1977); Data Line Corp. v. Micro Technologies, Inc., 813 F.2d 1196, 1 USPQ2d 2052 (Fed. Cir. 1987).
• (C) There are insubstantial differences between the prior art element and the corresponding element disclosed in the specification. IMS Technology, Inc. v. Haas Automation, Inc., 206 F.3d 1422, 1436, 54 USPQ2d 1129, 1138 (Fed. Cir. 2000); Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 41 USPQ2d 1865, 1875 (1997); Valmont Industries, Inc. v. Reinke Mfg. Co., 983 F.2d 1039, 25 USPQ2d 1451 (Fed. Cir. 1993). See also Caterpillar Inc. v. Deere & Co., 224 F.3d 1374, 56 USPQ2d 1305 (Fed. Cir. 2000) (A structure lacking several components of the overall structure corresponding to the claimed function and also differing in the number and size of the parts may be insubstantially different from the disclosed structure. The limitation in a means- (or step-) plus-function claim is the overall structure corresponding to the claimed function. The individual components of an overall structure that corresponds to the claimed function are not claim limitations. Also, potential advantages of a structure that do not relate to the claimed function should not be considered in an equivalents determination under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph).

A showing of at least one of the above-noted factors by the examiner should be sufficient to support a conclusion that the prior art element is an equivalent. The examiner should then conclude that the claimed limitation is met by the prior art element. In addition to the conclusion that the prior art element is an equivalent, examiners should also demonstrate, where appropriate, why it would have been obvious to one of ordinary skill in the art at the time of the invention to substitute applicant’s described structure, material, or acts for that described in the prior art reference. See In re Brown, 459 F.2d 531, 535, 173 USPQ 685, 688 (CCPA 1972). The burden then shifts to applicant to show that the element shown in the prior art is not an equivalent of the structure, material or acts disclosed in the application. In reMulder, 716 F.2d 1542, 219 USPQ 189 (Fed. Cir. 1983). No further analysis of equivalents is required of the examiner until applicant disagrees with the examiner’s conclusion, and provides reasons why the prior art element should not be considered an equivalent. See also In re Walter, 618 F.2d 758, 768, 205 USPQ 397, 407-08 (CCPA 1980) (treating 35 U.S.C. 112, sixth paragraph, in the context of a determination of statutory subject matter and noting “[i]f the functionally-defined disclosed means and their equivalents are so broad that they encompass any and every means for performing the recited functions . . . the burden must be placed on the applicant to demonstrate that the claims are truly drawn to specific apparatus distinct from other apparatus capable of performing the identical functions”); In reSwinehart, 439 F.2d 210, 212-13, 169 USPQ 226, 229 (CCPA 1971) (treating as improper a rejection under 35 U.S.C. 112, second paragraph, of functional language, but noting that “where the Patent Office has reason to believe that a functional limitation asserted to be critical for establishing novelty in the claimed subject matter may, in fact, be an inherent characteristic of the prior art, it possesses the authority to require the applicant to prove that the subject matter shown to be in the prior art does not possess the characteristics relied on”); In reFitzgerald, 619 F.2d 67, 205 USPQ 594 (CCPA 1980) (indicating that the burden of proof can be shifted to the applicant to show that the subject matter of the prior art does not possess the characteristic relied on whether the rejection is based on inherency under 35 U.S.C. 102 or obviousness under 35 U.S.C. 103).

See MPEP § 2184 when determining whether the applicant has successfully met the burden of proving that the prior art element is not equivalent to the structure, material or acts described in the applicant’s specification.

IF NONEQUIVALENCE SHOWN, EXAMINER MUST CONSIDER OBVIOUSNESS

However, even where the applicant has met that burden of proof and has shown that the prior art element is not equivalent to the structure, material or acts described in the applicant’s specification, the examiner must still make a 35 U.S.C. 103 analysis to determine if the claimed means- (or step-) plus-function would have been obvious from the prior art to one of ordinary skill in the art. Thus, while a finding of nonequivalence prevents a prior art element from anticipating a means- (or step-) plus-function limitation in a claim, it does not prevent the prior art element from rendering the claim limitation obvious to one of ordinary skill in the art. Because the exact scope of an “equivalent” may be uncertain, it would be appropriate to apply a 35 U.S.C. 102/103 rejection where the balance of the claim limitations are anticipated by the prior art relied on. A similar approach is authorized in the case of product-by-process claims because the exact identity of the claimed product or the prior art product cannot be determined by the examiner. In reBrown, 450 F.2d 531, 173 USPQ 685 (CCPA 1972). In addition, although it is normally the best practice to rely on only the best prior art references in rejecting a claim, alternative grounds of rejection may be appropriate where the prior art shows elements that are different from each other, and different from the specific structure, material or acts described in the specification, yet perform the function specified in the claim.

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