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Claims Not Indefinite Just Because Method Claims Included Structural Limitations, Apparatus Claims Included Functional Limitations, and a Term Was Used in Different Contexts in the Same Claim

April 01, 2008

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Last Month at the Federal Circuit - May 2008

Judges: Newman, Gajarsa (author), Dyk

[Appealed from: C.D. Cal., Chief Judge Stotler]

In Microprocessor Enhancement Corp. v. Texas Instruments Inc., Nos. 07-1249, -1286 (Fed. Cir. Apr. 1, 2008), the Federal Circuit reversed the district court’s grant of SJ of invalidity that all claims of U.S. Patent No. 5,471,593 (“the ’593 patent”) owned by Microprocessor Enhancement Corporation (“MEC”) were indefinite, but affirmed its grant of SJ of noninfringement in favor of Texas Instruments Inc. (“TI”) and Intel Corporation (“Intel”).

The ’593 patent is directed to methods for increasing microprocessor efficiency and pipelined processors, which operate like assembly lines, where the processor is subdivided into segments, each of which simultaneously completes its respective task on a different instruction. MEC initially sued both TI and Intel for infringement of the ’593 patent. The parties, however, concluded that Intel had been misjoined and stipulated to the dismissal of MEC’s claims against Intel. MEC subsequently refiled its claims against Intel in a separate suit.

In the TI case, the district court granted TI’s motions for SJ of invalidity for indefiniteness and noninfringement. With respect to invalidity, the district court concluded that claim 1, a method claim, and claim 7, an apparatus claim, were indefinite in that the claims impermissibly mixed two distinct classes of patentable subject matter and that they were insolubly ambiguous for requiring that a “condition code” be interpreted differently in different portions of a claim. As for noninfringement, the district court’s holding was based on its construction of the claim terms “pipeline stage” and “instruction execution pipeline stage.” Given its invalidity and noninfringement holdings, the district court entered judgment in TI’s favor.

At the time the district court entered judgment in the TI case, cross-motions for SJ were pending in the Intel case. Rather than wait for the district court to rule on the motions, MEC and Intel agreed to a stipulated dismissal in which MEC agreed that it would be collaterally estopped from challenging the TI case invalidity ruling and that the district court would apply the TI case claim construction, under which Intel’s accused products did not infringe. As a result, the district court entered judgment in Intel’s favor.

MEC appealed from the district court’s judgment in both cases. On MEC’s motion, the Federal Circuit consolidated the appeals.

The Court first addressed the parties dispute as to the scope of the record on appeal. Specifically, the parties disagreed as to whether the record included certain evidence submitted in the Intel case. The Federal Circuit noted that it did not need to decide this issue because its decision primarily rested on the intrinsic record of the ’593 patent and any differences between the extrinsic record developed in the two cases did not contradict its reading of the intrinsic record.

The Federal Circuit then turned to the district court’s grant of SJ of invalidity. It concluded that neither claim 1 nor claim 7 impermissibly claimed mixed classes of subject matter. The Court explained that a single patent may include claims directed to one or more of the classes of patentable subject matter, but no single claim may cover more than one subject matter class. Examining claim 1, the Court noted that it had the following structure: “A method of executing instructions in a pipelined processor comprising: [structural limitations of the pipelined processor]; the method further comprising: [method steps implemented in the pipelined processor].” Slip op. at 12 (alterations in original). The Court stated that although the preamble within a preamble structure was unconventional, method claim preambles often recite the physical structures of a system in which the claimed method is practiced. Moreover, reasoning that direct infringement of claim 1 was clearly limited to practicing the claimed method in a pipelined processor possessing the requisite structure, the Court concluded that claim 1 did not impermissibly mix two distinct classes of patentable subject matter. Similarly, the Court concluded that claim 7 did not cover both an apparatus and a method of use of that apparatus. The Court emphasized that apparatus claims are not necessarily indefinite for using functional language. It noted that claim 7 was clearly limited to a pipelined processor possessing the recited structure and was capable of performing the recited functions, and was thus not indefinite.

The Court also concluded that neither claim 1 nor claim 7 was insolubly ambiguous in its use of the term “condition code.” Both claims recited “at least one condition code” as an element of the pipelined processor. Thereafter, each claim referred to “the condition code” or “said condition code” five times. Examining the claims, the Court concluded that “condition code” meant either a storage unit or a value derived from the output of the storage unit depending on the context in which it is used, but that both claims were facially nonsensical if either of these definitions were used exclusively. Although the Court agreed with the district court’s initial assumption that a single claim term should be construed consistently with its appearance in other places in the same claim, the Court stated that a patentee’s mere use of a term with an antecedent does not require that both terms have the same meaning. The Court noted that ‘“[a] claim that is amenable to construction is not invalid on the ground of indefiniteness’ if the construction renders the claim definite.” Id. at 15 (alteration in original) (quoting Energizer Holdings, Inc. v. Int’l Trade Comm’n, 435 F.3d 1366, 1371 (Fed. Cir. 2006)).

Since the term “condition code” as used in the claims was not surrounded by uniform language that required a single interpretation and the appropriate meaning was readily apparent from each occurrence in the text, the Court concluded that the use of “condition code” in different contexts did not render the claims indefinite.

Finally, the Federal Circuit turned to the district court’s grant of SJ of noninfringement. The Court noted that MEC admitted that the accused products would not infringe if the Court affirms either the construction of “pipeline stage” or “instruction execution pipeline stage.” Thus, because the Court affirmed the district court’s construction of “pipeline stage,” it noted that it did not need to address the construction of “instruction execution pipeline stage.” In so doing, the Court noted that the district court’s construction of “pipeline stage” was supported by MEC’s admissions, the structure and context of the term’s use in the claims, the prosecution history, and extrinsic evidence of how the term would be understood by a person of ordinary skill in the art. The Court then noted that the parties had agreed that the accused products did not practice any of the asserted claims under the district court’s construction of “pipeline stage,” and that accordingly, the district court correctly entered SJ of noninfringement.