"Plain Meaning" of Claim Terms Determined Without Extrinsic Evidence

Using the plain and ordinary meaning of the claim terms, the specification and the prosecution history, the U.S. Court of Appeals for the Federal Circuit affirmed-in-part and reversed-in-part the district court’s claim construction, and in doing so broadened the meaning of the disputed term "regularly received television signals." Superguide Corp. v. DirecTV Enterprises, Inc., Case No. 02-1561 (Fed. Cir. Feb. 12, 2004) (Prost, J.) (concurring opinion by Michel, J.)

The district court, relying on the specification of the patent-in-suit, limited the claim term "regularly received television signals" to analog signals. This was based on the explanation in the patent that "when the programming guide is not in use the received television signals are sent directly through the RF section to the television for viewing" and on the fact that only analog signals were broadcast in 1985 (the year the application for the patent was filed). Superguide asserted that the plain meaning of the disputed