Opinion ID: 779640
Heading Depth: 3
Heading Rank: 3

Heading: color control means

Text: 56 The color control means limitation appears in claims 2, 4, and 7 of the '481 patent, and claims 2 and 4 of the '561 patent. The limitation appearing in claim 2 of the '481 patent is representative: color control means for selectively controlling the durations of the pulses applied to the light sources in the selected display areas to control the portions of the primary color light signals emitted therefrom, to thereby control the color of the exhibited display unit. 57 '481 patent, col. 9, ll. 59-64. The district court construed this limitation to be a means-plus-function limitation — a conclusion with which we agree. Neither party disputes that this limitation is subject to 35 U.S.C. § 112, paragraph six. That paragraph states: 58 An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof. 59 35 U.S.C. § 112, para. 6 (2000). 60 Because this limitation is expressed in `means plus function' language and because it does not recite definite structure in support of its function, it is subject to the requirements of 35 U.S.C. § 112, ¶ 6 (1994). B. Braun Med., Inc. v. Abbott Labs., 124 F.3d 1419, 1424, 43 USPQ2d 1896, 1899 (Fed.Cir.1997). The first step in construing such a limitation is to identify the function of the means-plus-function limitation. Micro Chem., Inc. v. Great Plains Chem. Co., 194 F.3d 1250, 1258, 52 USPQ2d 1258, 1263 (Fed.Cir.1999). The next step is to identify the corresponding structure in the written description necessary to perform that function. Id. 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. Braun, 124 F.3d at 1424, 43 USPQ2d at 1900. 61 The district court instructed the jury concerning the claimed function: 62 The color control means performs the function of selectively controlling the on times of the light sources to control the portions of primary color light signals for controlling the color of the composite light signal. 63 The district court described the corresponding structure from the specification as the structure that performs as disclosed in the specification of the display decoder and decoder driver. 64 Telegenix argues that the district court erred by misidentifying both the claimed function and the corresponding structure from the specification. We agree. The function recited in the asserted claims does not include selectively controlling the on times of the light sources. Instead, the claim recites selectively controlling the durations of the pulses applied to the light sources.... To the extent that the district court failed to follow the claim language in defining the function, it erred. See Micro Chem., 194 F.3d at 1258, 52 USPQ2d at 1263 (The statute does not permit limitation of a means-plus-function claim by adopting a function different from that explicitly recited in the claim.). 65 The district court further erred in its identification of the display decoder and decoder driver as the corresponding structure in the specification. 66 Section 112, ¶ 6, as is well-documented, was intended to permit use of means expressions without recitation of all the possible means that might be used in a claimed apparatus.... The price that must be paid for use of that convenience is limitation of the claim to the means specified in the written description and equivalents thereof. 67 O.I. Corp. v. Tekmar Co., 115 F.3d 1576, 1583, 42 USPQ2d 1777, 1782 (Fed.Cir.1997) (citations omitted). The duty to link or associate structure in the specification to the recited function is the quid pro quo for the convenience of employing § 112, paragraph 6. Braun, 124 F.3d at 1424, 43 USPQ2d at 1899. In the specification, the structure linked to the recited function of selectively controlling the durations of the pulses applied to the light sources includes the memory and counter circuitry illustrated in Figure 9. See '481 patent, col. 4, ll. 24-59. It was error for the district court to omit this structure from its claim construction of the color control means. 68 Accordingly, we conclude that the color control means performs the function of selectively controlling the durations of the pulses applied to the light sources to control the portions of the primary color light signals, to thereby control the color of the exhibited display unit. Moreover, we hold that the corresponding structure includes the memory 76, the counters 71e and 71f, the flip-flop 73, and associated connection circuitry illustrated in Figures 5 and 9. The color control means is limited to this corresponding structure and equivalents thereof. 69