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Court Starts with Dictionaries to Construe “High Frequency”

July 21, 2003

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Last Month at the Federal Circuit - August 2003

Judges: Schall (author), Gajarsa, and Dyk

In Intellectual Property Development, Inc. v. UA-Columbia Cablevision of Westchester, Inc., No. 02-1248 (Fed. Cir. July 21, 2003), the Federal Circuit affirmed the district court’s SJ ruling that UA-Columbia Cablevision of Westchester, Inc. and Tele-Communications, Inc. (collectively “Cablevision”) did not infringe U.S. Patent No. 4,135,202 (“the ’202 patent”) asserted by Intellectual Property Development, Inc. and Communications Patents, Ltd. (collectively “IPD”). Further, the Federal Circuit reversed the district court’s SJ ruling of invalidity for indefiniteness of the ’202 patent.

The ‘202 patent is directed to broadcasting systems with fiber-optic transmission lines. The district court had initially construed the claim term “high frequency” to include the VHF range, i.e., 54 to 216 MHz received by conventional television receivers at the time, but later reconsidered and reconstrued “high frequency carrier” to be limited to 3 to 30 MHz. Based on this construction, the district court granted the SJ of noninfringement, because Cablevision’s systems only operate above 30 MHz. IPD never argued that Cablevision met the “high frequency carrier” limitation under the DOE.

The Federal Circuit reviewed the claim construction de novo by first analyzing the words of the claim. The Federal Circuit held that the district court did not err in looking to dictionary definitions before consulting the specification or the prosecution history to first determine the ordinary and customary meaning of the term “high frequency.” The Federal Circuit agreed that, based on the dictionary definitions of “high frequency,” one skilled in the art at the time of the patent application would have understood “high frequency” to mean a frequency between 3 to 30 MHz. Consulting the intrinsic record, the Federal Circuit found that the specification and prosecution history do not clearly suggest a special definition for the term “high frequency.” Rather, they support the ordinary meaning as being 3 to 30 MHz.

IPD argued that the use of the phrase “conventional television receivers” in connection with “high frequency transmission” would have meant to a person skilled in the art that the inventor was referring to a VHF system operating in at least a range of 54 to 216 MHz, the operating frequencies of conventional television receivers at that time. The Federal Circuit, however, concluded that the ordinary meaning of “high frequency” helps define the term “conventional television receivers,” not the reverse.

The district court had also found claim 1 invalid under 35 U.S.C. § 112, paragraph 2, as indefinite for two reasons. First, the district court had found that the patent fails to disclose a structure clearly linked to the claimed “light beam demodulation means.” The parties did not dispute that the structure in the specification linked to the recited “photo-sensitive detector means” was the photo-sensitive detector described and shown in the specification. IPD argued that this same structure corresponded to the “light beam demodulation means.” The district court had concluded, however, that the “photo-sensitive detector means” and “light beam demodulation means” could not be the same structure because if they were, they could not be “responsive to” each other, as recited in the claim. The Federal Circuit disagreed, however, and, pointing to testimony by both experts that identified the corresponding structure, concluded that one skilled in the art would determine that the photosensitive detector disclosed in the specification and figures performed the claimed “light beam demodulation.”

The district court also found claim 1 invalid because the term “common optical fiber“ was indefinite. Claim 1 reads: “a common optical fiber . . . extending between an electro-optical transducer at said central station . . . and photo-sensitive detector means.” The district court assumed that a common optical fiber must be common over the entire distance between the transducer and the detector, which was not disclosed in the patent.

The Federal Circuit determined that the common optical fiber is a fiber that carries signals for a plurality of subscribers. Thus, even if the fiber were viewed as consisting of multiple segments with a segment of fiber branching off from it (“fiber tap”), it would not preclude a person skilled in the art from considering such a multisegment fiber leading to the detector to be a single “optical fiber” that is common (i.e., shared by) the end-users served by it. Accordingly, the Federal Circuit reversed the district court’s SJ ruling of invalidity with respect to the “common fiber” term.