2182 Scope of the Search and Identification of the Prior Art [R-2]
As noted in MPEP § 2181, in In reDonaldson Co., 16 F.3d 1189, 29 USPQ2d 1845 (Fed. Cir. 1994) the Federal Circuit recognized that it is important to retain the principle that claim language should be given its broadest reasonable interpretation. This principle is important because it helps insure that the statutory presumption of validity attributed to each claim of an issued patent is warranted by the search and examination conducted by the examiner. It is also important from the standpoint that the scope of protection afforded by patents issued prior to Donaldson are not unnecessarily limited by the latest interpretation of this statutory provision. Finally, it is important from the standpoint of avoiding the necessity for a patent specification to become a catalogue of existing technology. The specification need not describe the equivalents of the structures, material, or acts corresponding to the means- (or step-) plus-function claim element. See In re Noll, 545 F.2d 141, 149-50, 191 USPQ 721, 727 (CCPA 1976) (“The meaning of ‘equivalents’ is well understood in patent law, … and an applicant need not describe in his specification the full range of equivalents of his invention.”) (citation omitted). A patent specification need not teach, and preferably omits, what is well known in the art. Hybritech Inc.v.Monoclonal Antibodies, Inc., 802 F.2d 1367, 1384, 231 USPQ 81, 94 (Fed. Cir. 1986).
The Donaldson decision thus does not substantially alter examining practice and procedure relative to the scope of the search. Both before and after Donaldson, the application of a prior art reference to a means or step plus function limitation requires that the prior art element perform the identical function specified in the claim. However, if a prior art reference teaches identity of function to that specified in a claim, then under Donaldson an examiner carries the initial burden of proof for showing that the prior art structure or step is the same as or equivalent to the structure, material, or acts described in the specification which has been identified as corresponding to the claimed means or step plus function.
The “means or step plus function” limitation should be interpreted in a manner consistent with the specification disclosure. > The Federal Circuit explained the two step analysis involved in construing means-plus-function limitations in Golight Inc. v. Wal-Mart Stores Inc., 355 F.3d 1327, 1333-34, 69 USPQ2d 1481, 1486 (Fed. Cir. 2004):
The first step in construing a means-plus-function claim limitation is to define the particular function of the claim limitation. Budde v. Harley-Davidson, Inc., 250 F.3d 1369, 1376 [58 USPQ2d 1801, 1806] (Fed. Cir. 2001). “The court must construe the function of a means-plus-function limitation to include the limitations contained in the claim language, and only those limitations.” Cardiac Pacemakers, Inc. v. St. Jude Med., Inc., 296 F.3d 1106, 1113 [63 USPQ2d 1725, 1730] (Fed. Cir. 2002)…. The next step in construing a means-plus-function claim limitation is to look to the specification and identify the corresponding structure for that function. “Under this second step, ‘structure disclosed in the specification is “corresponding” structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim.’” Med. Instrumentation & Diagnostics Corp. v. Elekta AB, 344 F.3d 1205, 1210 [68 USPQ2d 1263, 1267] (Fed. Cir. 2003) (quoting B. Braun Med. Inc. v. Abbott Labs., 124 F.3d 1419, 1424 [43 USPQ2d 1896, 1900] (Fed. Cir. 1997)). <
If the specification defines what is meant by the limitation for the purposes of the claimed invention, the examiner should interpret the limitation as having that meaning. If no definition is provided, some judgment must be exercised in determining the scope of the limitation. See, e.g., B. Braun Medical, Inc. v. Abbott Labs., 124 F.3d 1419, 1424, 43 USPQ2d 1896, 1900 (Fed. Cir. 1997) (“We hold that, pursuant to [35 U.S.C. 112, sixth paragraph], structure disclosed in the specification is ‘corresponding’ structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim. This duty to link or associate structure to function is the quid pro quo for the convenience of employing 112, paragraph 6.” The court refused to interpret a means-plus-function limitation as corresponding to a disclosed valve seat structure, as argued by patentee, since there was no indication in the specification or prosecution history that this structure corresponds to the recited function, and there was an explicitly clear association between that function and a traverse cross section bar structure disclosed in the specification.).