Mar 16, 2020Legal
Disclaimer Not Required for Prosecution History to Limit Claim Scope


Before Reyna, Taranto and Stoll.  Appeal from the Patent Trial and Appeal Board.

Summary: Prosecution history evidence need not rise to the level of disclaimer to inform the meaning of disputed claim limitations.

Personalized Media Communication (PMC) challenges the Patent Trial and Appeal Board’s construction of the claim limitation “an encrypted digital information transmission including encrypted information.” PMC argued that the disputed claim limitation should be construed narrowly to include only “digital transmissions.” The Board rejected PMC’s position, finding that the limitation did not exclude transmissions of information that is non-encrypted or analog. Based on this construction, the Board invalided the challenged claims over the cited prior art.

On appeal, the Federal Circuit affirmed-in-part and reversed-in-part the Board’s decision. In reaching its decision, The Federal Circuit acknowledged that although the Board’s construction of the terms in light of the claim language and specification is plausible, the prosecution history evidence compelled a narrower construction.  Here, the applicant’s claim amendments and consistent statements during prosecution clarified that the disputed claim limitation was limited to digital transmissions, even though the statements may not have risen to the level of disclaimer. Because it was undisputed that the cited prior art was not limited to digital transmissions, the Federal Circuit reversed the Board’s final written decision invalidating claims containing the disputed limitation.

Editor: Paul Stewart

Written by: Andrea Cheek

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