IP News

In Microprocessor Enhancement Corp. v. Texas Instruments Corp., No. 2007-1249, -1268, decided April 1, 2008, the Federal Circuit held that method claims are not necessarily indefinite where they recite features of the apparatus in which a claimed method is practiced. Citing its earlier decision in IPXL Holdings LLC v. Amazon.com, Inc., 430 F.3d 1377 (Fed. Cir. 2005) and William Shakespeare, the Federal Circuit held that while 'no single claim may cover more than one subject matter class,' any 'seeming preamble within a preamble structure,' though it may be 'unconventional,' must have 'the conclusiveness with which King Claudius's guilt is established by his reaction to Hamlet's play within a play' in its effect on definiteness if it is to render a claim invalid. The Microprocessor court distinguished the IPXL Holdings decision, stating that it 'was based on the lack of clarity as to when the mixed subject matter claim would be infringed,' which did not exist in the instant claims which were 'clearly limited to practicing the claimed method in a pipelined processor possessing the requisite structure.'

In Microprocessor, the Federal Circuit interpreted the structure of challenged claim 1 to be described as 'A method of executing instructions in a pipeline comprising: [structural limitations of the pipeline processor]; the method further comprising: [method steps implemented in the pipelined processor].' While the defendant argued that the claim therefore combined subject matter pertaining to both a method and a system in a manner impermissible under IPXL Holdings, the Federal Circuit held that since there was no lack of clarity as to what subject matter was claimed, claim 1 was 'no different' from permissible '[m]ethod claim preambles [which] often recite the physical structures of a system in which the claimed method is practiced.'