Welcome to Winston & Strawn’s Federal Circuit Patent Decision Summaries. This bulletin provides a short summary of, and links to, the precedential patent cases decided by the Federal Circuit last week. We hope that these summaries are useful in keeping you updated on the Federal Circuit’s patent decisions.

Where the relevant factual inquiries underlying an obviousness determination are otherwise clear, characterization by the examiner of prior art as “primary” and “secondary” is merely a matter of presentation with no legal significance, and in considering whether a prior art reference “teaches away” from a claimed invention in determining obviousness, a known system does not become patentable simply because it has been described as somewhat inferior to some other product for the same use.

In re Mouttet, No. 2011-1451 (Fed. Cir. June 26, 2012).

The Board of Patent Appeals and Interferences (the Board) affirmed the rejection of all pending patent claims on obviousness grounds. Because it found that substantial evidence supports the Board’s factual determinations, and because it concluded that the applicant’s claimed invention would have been obvious to one of ordinary skill in the art, the Federal Circuit affirmed. 

The applicant’s claimed computing device (“crossbar array”) involves electrical circuits. The Board relied on three pieces of prior art in rejecting the patent claims: Falk, Das, and Terepin. Falk discloses a computing device with all the recited limitations of the applicant’s representative claims except that Falk lacks an A/D converter (taught by Terepin) and uses optical paths rather than electrical wire for the crossbar array (taught by Das). 

The applicant argued that substituting electronic hardware for optical hardware would destroy Falk’s principle of operation and physical structure. However, Falk’s principle of operation is its high level ability to receive inputs into a programmable crossbar array and processing the output to obtain an arithmetic result, which is not unique to optical circuitry. The Board’s determination that the difference in the circuitry (electrical vs. optical) does not affect the overall principle of operation was therefore supported by substantial evidence. The applicant further argued that replacing Falk’s optical circuitry with Das’s electrical circuitry would destroy Falk’s physical structure. “It is well-established that a determination of obviousness based on teachings from multiple references does not require an actual, physical substitution of elements.” “[I]t was not requisite to the Board’s [obviousness] determination that Das’s features be deemed equivalent for purposes of substitution into Falk’s device.” A person of ordinary skill would have recognized that Falk could have been combined with Das to predictably yield the applicant’s claimed computing device. In addition, the applicant erroneously assumed that because the Board designated Falk as the “base reference,” Falk’s optically based implementation is a controlling principle of operation that any prior art must preserve. “[W]here the relevant factual inquiries underlying an obviousness determination are otherwise clear, characterization by the examiner of prior art as ‘primary’ and ‘secondary’ is merely a matter of presentation with no legal significance.”

The applicant also argued that Falk teaches away from the claimed invention because Falk mentions that optical circuits are superior to electronic circuits for certain purposes. However, the applicant failed to cite any reference suggesting that the claimed invention would be unlikely to work using electrical circuitry. “[A] known system such as an arithmetic/logic unit ‘does not become patentable simply because it has been described as somewhat inferior to some other product for the same use,’ such as an arithmetic/logic unit having electrical circuitry despite fewer interconnect possibilities than optical circuitry.”

A copy of the opinion can be found here.