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2114 Apparatus and Article Claims — Functional Language [R-07.2015]

For a discussion of case law which provides guidance in interpreting the functional portion of means-plus-function limitations see MPEP § 2181 - § 2186.


Features of an apparatus may be recited either structurally or functionally. In re Schreiber, 128 F.3d 1473, 1478, 44 USPQ2d 1429, 1432 (Fed. Cir. 1997). See also MPEP § 2173.05(g). If an examiner concludes that a functional limitation is an inherent characteristic of the prior art, then to establish a prima case of anticipation or obviousness, the examiner should explain that the prior art structure inherently possesses the functionally defined limitations of the claimed apparatus. In re Schreiber, 128 F.3d at 1478, 44 USPQ2d at 1432. See also Bettcher Industries, Inc. v. Bunzl USA, Inc., 661 F.3d 629, 639-40,100 USPQ2d 1433, 1440 (Fed. Cir. 2011). The burden then shifts to applicant to establish that the prior art does not possess the characteristic relied on. In re Schreiber, 128 F.3d at 1478, 44 USPQ2d at 1432; In re Swinehart, 439 F.2d 210, 213, 169 USPQ 226, 228 (CCPA 1971) (“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 characteristic relied on”).


“[A]pparatus claims cover what a device is, not what a device does.” Hewlett-Packard Co.v.Bausch & Lomb Inc., 909 F.2d 1464, 1469, 15 USPQ2d 1525, 1528 (Fed. Cir. 1990) (emphasis in original). A claim containing a “recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus” if the prior art apparatus teaches all the structural limitations of the claim. Ex parte Masham, 2 USPQ2d 1647 (Bd. Pat. App. & Inter. 1987) (The preamble of claim 1 recited that the apparatus was “for mixing flowing developer material” and the body of the claim recited “means for mixing ..., said mixing means being stationary and completely submerged in the developer material.” The claim was rejected over a reference which taught all the structural limitations of the claim for the intended use of mixing flowing developer. However, the mixer was only partially submerged in the developer material. The Board held that the amount of submersion is immaterial to the structure of the mixer and thus the claim was properly rejected.).


Even if the prior art device performs all the functions recited in the claim, the prior art cannot anticipate the claim if there is any structural difference. It should be noted, however, that means-plus-function limitations are met by structures which are equivalent to the corresponding structures recited in the specification. In re Donaldson, 16 F.3d 1189, 1193, 29 USPQ2d 1845, 1848 (Fed. Cir. 1994). See also In re Robertson, 169 F.3d 743, 745, 49 USPQ2d 1949, 1951 (Fed. Cir. 1999) (The claims were drawn to a disposable diaper having three fastening elements. The reference disclosed two fastening elements that could perform the same function as the three fastening elements in the claims. The court construed the claims to require three separate elements and held that the reference did not disclose a separate third fastening element, either expressly or inherently.).


Functional claim language that is not limited to a specific structure covers all devices that are capable of performing the recited function. Therefore, if the prior art discloses a device that can inherently perform the claimed function, a rejection under 35 U.S.C. 102 and/or 35 U.S.C. 103 may be appropriate. See In re Translogic Technology, Inc., 504 F.3d 1249, 1258, 84 USPQ2d 1929, 1935-1936 (Fed. Cir. 2007) (The claims were drawn to multiplexer circuit. The patent at issue claimed “coupled to” and “coupled to receive” between various portions of the circuitry. In reference to the claim phrase “input terminals ‘coupled to receive’ first and second input variables,” the court held that “the claimed circuit does not require any specific input or connection … [a]s such, ‘coupled to’ and ‘coupled to receive’ are clearly different … [a]s shown in [the figures of the] patent, input terminals … only need to be ‘capable of receiving’ an input variable for the multiplexer circuit as claimed”. Therefore, the specification supported the claim construction “that ‘coupled to receive’ means ‘capable of receiving.’”); Intel Corp. v. U.S. Int'l Trade Comm’n, 946 F.2d 821, 832, 20 USPQ2d 1161, 1171 (Fed. Cir. 1991) (The court held that “programmable” claim language required only that the accused product could be programmed to perform the claimed functionality.);In re Schreiber, 128 F.3d 1473, 1478, 44 USPQ2d 1429, 1432 (Fed. Cir. 1997); In re Best, 562 F.2d 1252, 1254, 195 USPQ 430, 433 (CCPA 1977); In re Ludtke, 441 F.2d 660, 663-64, 169 USPQ 563, 566-67 (CCPA 1971); In re Swinehart, 439 F.2d 210, 212-13, 169 USPQ 226, 228-29 (CCPA 1971) (“[I]t is elementary that the mere recitation of a newly discovered function or property, inherently possessed by things in the prior art, does not cause a claim drawn to those things to distinguish over the prior art”). See MPEP § 2112 for more information.

Conversely, computer-implemented functional claim limitations may narrow the functionality of the device, by limiting the specific structure capable of performing the recited function. Nazomi Communications, Inc. v. Nokia Corp., 739 F.3d 1339, 1345, 109 USPQ2d 1258, 1262 (Fed Cir. 2014) (The claims were drawn to a CPU that can perform processing of both register-based and stack-based instructions. Appellant alleged infringement of the claims based on claim construction requiring only hardware capable of performing the claimed functionalities. Contrasted with the finding of Intel Corp. v. U.S. Int'l Trade Comm’n, 846 F.2d 821, 832, 20 USPQ2d 1161, 1171 (Fed. Cir. 1991), the court found that “[s]ince hardware cannot meet these limitations in the absence of enabling software, the claims are properly construed as claiming an apparatus comprising a combination of hardware and software capable of practicing the claim limitations.”).

Computer-implemented functional claim limitations may also be broad because the term “computer” is commonly understood by one of ordinary skill in the art to describe a variety of devices with varying degrees of complexity and capabilities. In re Paulsen, 30 F.3d 1475, 1479-80, 31 USPQ2d 1671, 1674 (Fed. Cir. 1994). Therefore, a claim containing the term “computer” should not be construed as limited to a computer having a specific set of characteristics and capabilities, unless the term is modified by other claim terms or clearly defined in the specification to be different from its common meaning. Id. In Paulsen, the claims, directed to a portable computer, were rejected as anticipated under 35 U.S.C. 102 by a reference that disclosed a calculator, because the term “computer” was given the broadest reasonable interpretation consistent with the specification to include a calculator, and a calculator was considered to be a particular type of computer by those of ordinary skill in the art. Id.

When determining whether a computer-implemented functional claim would have been obvious, examiners should note that broadly claiming an automated means to replace a manual function to accomplish the same result does not distinguish over the prior art. See Leapfrog Enters., Inc. v. Fisher-Price, Inc., 485 F.3d 1157, 1161, 82 USPQ2d 1687, 1691 (Fed. Cir. 2007) (“Accommodating a prior art mechanical device that accomplishes [a desired] goal to modern electronics would have been reasonably obvious to one of ordinary skill in designing children’s learning devices. Applying modern electronics to older mechanical devices has been commonplace in recent years.”); In re Venner, 262 F.2d 91, 95, 120 USPQ 193, 194 (CCPA 1958); see also MPEP § 2144.04. Furthermore, implementing a known function on a computer has been deemed obvious to one of ordinary skill in the art if the automation of the known function on a general purpose computer is nothing more than the predictable use of prior art elements according to their established functions. KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 417, 82 USPQ2d 1385, 1396 (2007); see also MPEP § 2143, Exemplary Rationales D and F. Likewise, it has been found to be obvious to adapt an existing process to incorporate Internet and Web browser technologies for communicating and displaying information because these technologies had become commonplace for those functions. Muniauction, Inc. v. Thomson Corp., 532 F.3d 1318, 1326-27, 87 USPQ2d 1350, 1357 (Fed. Cir. 2008).

For more information on the obviousness determination, see MPEP § 2141.



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Last Modified: 02/16/2023 12:58:20