In a non-precedential decision addressing the weight given to a patentee’s statements concerning “the invention,” the U.S. Court of Appeals for the Federal Circuit reversed in part and affirmed in part the district court’s construction and remanded the case, finding that statements about “the invention” are non-limiting where the statements are contradicted by other statements and illustrations.  Creative Integrated Sys., Inc. v. Nintendo of Am., Inc., Case Nos. 12-1579, -1626 (Fed. Cir., June 3, 2013) (Reyna, J.).

The patent-in-suit relates to read only memory (ROM) and, in particular, to the memory cell array that forms one of the ROM’s components.  Memory cell arrays can be thought of as being organized into columns of memory cell blocks.  Metallization lines, such as virtual ground lines, connect these blocks to the main bit line, where the bit can ultimately be read. 

The district court construed claim language describing the metallization lines to require that the lines be connected to each end of each block.  In construing the claims, the district court began with the plain language of the claims, which required only that the plurality of blocks be coupled together by the metallization lines, with no requirement that each end of a single block be coupled to the other. 

Despite the plain language of the claim, the district court found that intrinsic evidence limited the claim scope.  One statement in the specification described the “invention” as having a plurality of contacts connected to the virtual ground lines and main bit line at each end of the block.  A second statement described the virtual ground lines and main bit line as having a contact connected at opposing ends of each block of memory cells.  The district court also relied on a statement the applicant made to the patent office that the metallization lines allow access to each block from either end of the block. Creative appealed.

While noting that statements describing the invention as a whole are more likely to support a limiting definition of claim terms, the Federal Circuit went on to state that “this principle has no application where, as here, the other statements and illustrations make it clear that the limitations do not describe the invention as a whole.”  The specification and drawings in this case described over a dozen improvements to ROM circuitry, and in each of the sections describing these unrelated improvements the particular improvement was identified as “the invention.”

Regarding the prosecution history, the Federal Circuit found that the statement in question was not a “clear and unambiguous disavowal” of claim scope.  The Federal Circuit noted that certain claims were amended to add limiting language directed to metallization lines where each end of each block is connected to the other, while other claims lacked such a limitation.   Thus, the Court concluded that the applicant’s statement described one embodiment of the invention, but did not disavow other embodiments that were not so limited in scope.

The Federal Circuit also found that the canon of claim differentiation provided additional support for the conclusion that the asserted claim was not limited to one of the preferred embodiments.  Specifically, an unasserted claim was limited to blocks where the metallization lines are connected at each end of each of the blocks.  The Federal Circuit found that reading the asserted claim to be similarly limited would render the language of the unasserted claim superfluous.