“Regularly Received Television Signal” Includes Both Older Analog and Newer Digital Signals
February 12, 2004
Last Month at the Federal Circuit - March 2004
Judges: Prost (author), Mayer, and Michel (concurring in the result)
In SuperGuide Corp. v. DirecTV Enterprises, Inc., No. 02-1561 (Fed. Cir. Feb. 12, 2004), the Federal Circuit vacated a grant of SJ of no infringement because it reversed-in-part the claim construction on which that SJ was based.
SuperGuide Corporation (“SuperGuide”), owner of U.S. Patent Nos. 4,751,578 (“the ‘578 patent); 5,038,211; and 5,293,357, sued a number of defendants for infringement of these patents. The patents relate generally to devices that receive program guides sent by television broadcasters, enable a television viewer to search the program guides, and display the results to the viewer. The infringement issues turned on the construction of various claim recitations.
One of the claim-construction issues involved whether three limitations (the “limitations- at-issue”) in claim 1 of the ‘578 patent, including the term “regularly received television signal,” covered digital signals or were limited to analog signals. Observing that the only type of television signals that were broadcast in 1985, the year in which the ‘578 patent was filed, were analog signals, the district court had held that the limitations-at-issue must be limited to analog television signals, not the digital television signals that later came into use. SuperGuide and Gemstar Development Corporation, a third-party defendant and exclusive licensee of the patents-in-suit in certain fields of use, challenged the district court’s claim construction.
In concluding that the limitations-at-issue encompass digital signals, the Federal Circuit found a number of factors persuasive. First, the claim language itself does not limit the disputed phrases to a particular signal format (analog or digital). Furthermore, the claim language does not explicitly limit the disputed terms to technologies that were conventional at the time of the invention. The Court also relied on evidence indicating that those skilled in the art knew that video data could be communicated in either analog or digital format and had developed certain digital video standards by the time the ‘578 patent was filed. Finally, the Court examined the prosecution history and held that none of the arguments the patentee made in distinguishing various references required an exclusion of digital signals from the literal scope of the limitations-at-issue.
Judge Michel disagreed with the majority’s claim construction for the limitations-at-issue. In his view, the majority’s construction improperly expands the scope of the ‘578 patent beyond what the inventors described and enabled. Moreover, he felt that the evidence that digital signals were known at the time the ‘578 patent was filed did not support the broad interpretation that the majority gave to the limitations-at-issue because such evidence did not sufficiently establish how one of ordinary skill in the television art would have viewed those terms at the time. He also criticized the majority for ignoring various declarations in evidence indicating that one skilled in the art would have understood the limitations-at-issue to encompass only analog television signals. Finally, Judge Michel raised his concern that the Court’s increasing reliance on “ordinary meaning” has obscured the correct claimconstruction analysis. In his opinion, the inventors had not invented a system that receives digital signals, so their patent cannot cover such systems. Though he disagreed with the majority’s interpretation of the limitations-atissue, heconcurred in the result for these limitations because he thought there are at least triable issues under the DOE.