Opinion ID: 779640
Heading Depth: 3
Heading Rank: 7

Heading: converter means

Text: 97 The phrase converter means is a limitation recited in claim 4 of the '890 patent. The district court interpreted this phrase to mean: 98 The converter means includes firmware, software and/or hardware that functions to convert said display color control signals to obtain complementary color control signals. 99 Telegenix argues that this interpretation is unsupported, because no software or firmware is mentioned anywhere in the specification. Telegenix argues that the structure disclosed for the converter means is the multiplexer and inverter arrangement described in the written description and figures. 100 TDS argues that its expert testified that one of ordinary skill in the art would have appreciated that the converter means could be implemented in hardware, software, and/or firmware. TDS argues that the function of the converter means includes providing a complementary color in response to the selected display area color, and the multiplexer does not perform this function. Instead, according to TDS, only the inverter performs this function. 101 There is no dispute that converter means is a means-plus-function limitation within the meaning of section 112, paragraph 6. Again, in construing such a limitation, the task of the district court is to first identify the function recited for the limitation, and next to identify the corresponding structure in the written description necessary to perform that function. See Micro Chem., 194 F.3d at 1258, 52 USPQ2d at 1263. 102 In its construction of the converter means, the district court failed to identify the corresponding structure from the specification. The district court correctly performed the first step by identifying the claimed function, to convert said display control color signals to obtain complementary color control signals. However, the court's description of the corresponding structure as includ[ing] firmware, software and/or hardware has no basis in the specification. TDS essentially admits in its brief that the testimony of TDS's expert was used to broaden the court's view of the corresponding structure beyond that disclosed in the specification and prosecution history. 103 TDS argues that the structure identified by the district court could qualify as equivalent structure under section 112, paragraph six. This argument misunderstands the deficiency in the district court's construction. Even if software and firmware could be equivalent structures under section 112, paragraph six, the court failed to correctly perform the second step of identifying the structure disclosed in the written description as corresponding to the recited function. Instead, the court identified a broad array of possible structures not mentioned anywhere in the specification. 104 We conclude that the district court erred in construing this limitation. Where the patent documents are unambiguous, expert testimony regarding the meaning of a claim is entitled to no weight. Vitronics, 90 F.3d at 1584, 39 USPQ2d at 1578. The converter means performs the function of converting the display color control signals to obtain complementary color control signals. The corresponding structure includes inverters 26a-c depicted in Fig. 3 and described in the specification at col. 3, ll. 31-39, and col. 4, ll. 8-27. The converter means is limited to this corresponding structure and equivalents thereof. 105