MPEP2181 IA
A.    THE CLAIM LIMITATION USES THE TERM "MEANS" OR "STEP" OR A GENERIC PLACEHOLDER (A TERM THAT IS SIMPLY A SUBSTITUTE FOR "MEANS")

With respect to the first prong of this analysis, a claim element that does not include the term "means" or "step" triggers a rebuttable presumption that 35 U.S.C. 112(f) does not apply. When the claim limitation does not use the term "means," examiners should determine whether the presumption that 35 U.S.C. 112(f) does not apply is overcome. The presumption may be overcome if the claim limitation uses a generic placeholder (a term that is simply a substitute for the term "means"). The following is a list of non-structural generic placeholders that may invoke 35 U.S.C. 112(f): "mechanism for," "module for," "device for," "unit for," "component for," "element for," "member for," "apparatus for," "machine for," or "system for." Welker Bearing Co., v. PHD, Inc., 550 F.3d 1090, 1096, 89 USPQ2d 1289, 1293-94 (Fed. Cir. 2008); Mass. Inst. of Tech. v. Abacus Software, 462 F.3d 1344, 1354, 80 USPQ2d 1225, 1228 (Fed. Cir. 2006); Personalized Media, 161 F.3d at 704, 48 USPQ2d at 1886–87; Mas-Hamilton Group v. LaGard, Inc., 156 F.3d 1206, 1214-1215, 48 USPQ2d 1010, 1017 (Fed. Cir. 1998). Note that there is no fixed list of generic placeholders that always result in 35 U.S.C. 112(f) interpretation, and likewise there is no fixed list of words that always avoid 35 U.S.C. 112(f) interpretation. Every case will turn on its own unique set of facts.

The standard is whether the words of the claim are understood by persons of ordinary skill in the art to have a sufficiently definite meaning as the name for structure." Williamson v. Citrix Online, LLC, 792 F.3d 1339, 1349, 115 USPQ2d 1105, 1111 (Fed. Cir. 2015). The issue in Williamson was whether a "distributed learning control module" limitation in claims directed to a distributed learning system should be interpreted as a means-plus-function limitation. See Williamson, 792 F.3d at 1347. The Federal Circuit concluded that ‘‘the ‘distributed learning control module’ limitation fails to recite sufficiently definite structure and that the presumption against means-plus function claiming is rebutted." Id. at 1351. In support, the Federal Circuit determined that "the word ‘module’ does not provide any indication of structure because it sets forth the same black box recitation of structure for providing the same specified function as if the term ‘means’ had been used." Id. at 1350–51.

If persons of ordinary skill in the art reading the specification understand the term to have a sufficiently definite meaning as the name for the structure that performs the function, even when the term covers a broad class of structures or identifies the structures by their function (e.g., "filters," "brakes," "clamp," "screwdriver," and "locks") 35 U.S.C. 112(f) will not apply. Apex Inc. v. Raritan Computer, Inc., 325 F.3d 1364, 1372-73, 66 USPQ2d 1444, 1451-52 (Fed. Cir. 2003); CCS Fitness, 288 F.3d at 1369, 62 USPQ2d at 1664; Watts v. XL Sys. Inc., 232 F.3d 877, 880-81, 56 USPQ2d 1836, 1839 (Fed. Cir. 2000); Personalized Media, 161 F.3d at 704, 48 USPQ2d at 1888; Greenberg v. Ethicon Endo-Surgery, Inc., 91 F.3d 1580, 1583, 39 USPQ2d 1783, 1786 (Fed. Cir. 1996) ("Many devices take their names from the functions they perform.") The term is not required to denote a specific structure or a precise physical structure to avoid the application of 35 U.S.C. 112(f). See Watts, 232 F.3d at 880, 56 USPQ2d at 1838; Inventio AG v. Thyssenkrupp Elevator Americas Corp., 649 F.3d 1350, 99 USPQ2d 1112 (Fed. Cir. 2011) (holding that the claim terms "modernizing device" and "computing unit" when read in light of the specification connoted sufficient, definite structure to one of skill in the art to preclude application of 35 U.S.C. 112, sixth paragraph). The following are examples of structural terms that have been found not to invoke 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, paragraph 6: "circuit," "detent mechanism," "digital detector," "reciprocating member," "connector assembly," "perforation," "sealingly connected joints," and "eyeglass hanger member." See Mass. Inst. of Tech., 462 F.3d at 1355-1356, 80 USPQ2d at 1332 (the court found the recitation of "aesthetic correction circuitry" sufficient to avoid pre-AIA 35 U.S.C. 112, paragraph 6, treatment because the term circuit, combined with a description of the function of the circuit, connoted sufficient structure to one of ordinary skill in the art.); Linear Tech. Corp. v. Impala Linear Corp., 379 F.3d 1311, 1321, 72 USPQ2d 1065, 1071 (Fed. Cir. 2004); Apex, 325 F.3d at 1373, 66 USPQ2d at 1452; Greenberg, 91 F.3d at 1583-84, 39 USPQ2d at 1786; Personalized Media, 161 F.3d at 704-05, 39 USPQ2d at 1786; CCS Fitness, 288 F.3d at 1369-70, 62 USPQ2d at 1664-65; Cole v. Kimberly-Clark Corp., 102 F.3d 524, 531 (Fed. Cir. 1996); Watts, 232 F.3d at 881, 56 USPQ2d at 1839; Al-Site Corp. v. VSI Int’l, Inc., 174 F.3d 1308, 1318-19, 50 USPQ2d 1161, 1166-67 (Fed. Cir. 1999).

For a term to be considered a substitute for "means," and lack sufficient structure for performing the function, it must serve as a generic placeholder and thus not limit the scope of the claim to any specific manner or structure for performing the claimed function. It is important to remember that there are no absolutes in the determination of terms used as a substitute for "means" that serve as generic placeholders. The examiner must carefully consider the term in light of the specification and the commonly accepted meaning in the technological art. Every application will turn on its own facts.

If the examiner has not interpreted a claim limitation as invoking 35 U.S.C. 112(f) and an applicant wishes to have the claim limitation treated under 35 U.S.C. 112(f) applicant must either: (A) amend the claim to include the phrase "means" or "step"; or (B) rebut the presumption that 35 U.S.C. 112(f) does not apply by showing that the claim limitation is written as a function to be performed and does not recite sufficient structure, material, or acts to perform that function. See Watts, 232 F.3d at 881, 56 USPQ2d at 1839 (Fed. Cir. 2000) (Claim limitations were held not to invoke 35 U.S.C. 112, sixth paragraph, because the absence of the term "means" raised the presumption that the limitations were not in means-plus-function form and the applicant did not rebut that presumption.); see also Masco Corp. v. United States, 303 F.3d 1316, 1327, 64 USPQ2d 1182, 1189 (Fed. Cir. 2002) ("[W]here a method claim does not contain the term ‘step[s] for,’ a limitation of that claim cannot be construed as a step-plus-function limitation without a showing that the limitation contains no act.").

Some of the following examples illustrate situations where the term "means" or "step" was not used but either the Board or courts nevertheless determined that the claim limitation fell within the scope of 35 U.S.C. 112(f). Note that the examples are fact specific and should not be applied as per se rules. See Signtech USA, Ltd. v. Vutek, Inc., 174 F.3d 1352, 1356, 50 USPQ2d 1372, 1374–75 (Fed. Cir.1999) ("ink delivery means positioned on …" invokes 35 U.S.C. 112, sixth paragraph since the phrase "ink delivery means" is equivalent to "means for ink delivery"); Seal-Flex, Inc. v. Athletic Track and Court Construction, 172 F.3d 836, 850, 50 USPQ2d 1225, 1234 (Fed. Cir. 1999) (Rader, J., concurring) ("Claim elements without express step-plus-function language may nevertheless fall within Section 112, Para. 6 if they merely claim the underlying function without recitation of acts for performing that function…. In general terms, the ‘underlying function’ of a method claim element corresponds to what that element ultimately accomplishes in relationship to what the other elements of the claim and the claim as a whole accomplish. ‘Acts,’ on the other hand, correspond to how the function is accomplished…. If the claim element uses the phrase ‘step for,’ then Section 112, Para. 6 is presumed to apply…. On the other hand, the term ‘step’ alone and the phrase ‘steps of’ tend to show that Section 112, Para. 6 does not govern that limitation."); Personalized Media, 161 F.3d at 703–04, 48 USPQ2d at 1886–87 (Fed. Cir. 1998); Mas-Hamilton, 156 F.3d at 1213, 48 USPQ2d at 1016 (Fed. Cir. 1998) ("lever moving element for moving the lever" and "movable link member for holding the lever…and for releasing the lever" were construed as means-plus-function limitations invoking 35 U.S.C. 112, sixth paragraph since the claimed limitations were described in terms of their function rather than their mechanical structure); Ethicon, Inc. v. United States Surgical Corp., 135 F.3d 1456, 1463, 45 USPQ2d 1545, 1550 (Fed. Cir. 1998) ("use of the word ‘means’ gives rise to a presumption that the inventor used the term advisedly to invoke the statutory mandates for means-plus-function clauses") (quotation omitted). However, compare Al-Site Corp. v. VSI Int’l, Inc., 174 F.3d 1308, 1317-19, 50 USPQ2d 1161, 1166-67 (Fed. Cir. 1999) (holding that although the claim elements "eyeglass hanger member" and "eyeglass contacting member" include a function, these claim elements do not invoke 35 U.S.C. 112, sixth paragraph because the claims themselves contain sufficient structural limitations for performing these functions); O.I. Corp. v. Tekmar, 115 F.3d 1576, 1583, 42 USPQ2d 1777, 1782 (Fed. Cir. 1997) (method claim that paralleled means-plus-function apparatus claim but lacked "step for" language did not invoke 35 U.S.C. 112, sixth paragraph).

When applicant uses the term "means" or "step" in the preamble, a rejection under 35 U.S.C. 112(b) may be appropriate when it is unclear whether the preamble is reciting a means- (or step-) plus- function limitation or whether the preamble is merely stating the intended use of the claimed invention. When applicant merely states an intended use of the claimed invention in the preamble (e.g., "A device for printing, comprising..."), the examiner should not construe such language as reciting a means-plus-function limitation.

The examiner is reminded that, absent a determination that a claim limitation invokes 35 U.S.C. 112(f), the broadest reasonable interpretation will not be limited to "corresponding structure… and equivalents thereof." Morris, 127 F.3d at 1055, 44 USPQ2d at 1028 ("no comparable mandate in the patent statute that relates the claim scope of non-§ 112 paragraph 6 claims to particular matter found in the specification").