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LAN Patent Limited to Disclosed Embodiment

February 15, 2002

Decision icon Decision

Last Month at the Federal Circuit - March 2002

Judges: Michel (author), Rader, and Bryson

In Datapoint Corp. v. Standard Microsystems Corp., No. 99-1239 (Fed. Cir. Feb. 15, 2002) (nonprecedential decision), the Federal Circuit affirmed a district court’s SJ of noninfringement after confirming the claim construction.

Datapoint Corporation (“Datapoint”) is the assignee of U.S. Patent Nos. 5,008,879 (“the ’879 patent”) and 5,077,732 (“the ’732 patent”), both drawn to local area networks (“LANs”). In 1996, Datapoint brought four patent infringement actions against numerous Defendants, alleging infringement of the ’879 and ’732 patents. The cases were consolidated and a SM was appointed to assist in supervising discovery and construing the claims.

After a Markman hearing, the SM issued a claim construction that limited the claims of the ‘879 and ‘732 patents to “bus-type LANs.” Over objections by Datapoint, the district court adopted the SM’s claim construction. Subsequently, Datapoint stipulated to a SJ of noninfringement and appealed.

On appeal, Datapoint argued that the SM had improperly limited the claims to the preferred embodiment, i.e., to bus-type LANs. Datapoint did not dispute that the only LANs shown in the ‘879 and ‘732 patents were bus-type LANs. However, Datapoint argued that the preambles of the claims recited “LANs” generally and the invention could be adapted to any type of LAN, not just bus-type LANs. Moreover, it argued, both the ‘879 and ‘732 patents state that “[a]lthough a bus-type logical connectivity is illustrated and described herein, the invention may be adapted to LANs having other types of predetermined logical connectivity patterns, for example, stars.”

The Federal Circuit disagreed that the claimed invention could be adapted to cover non-bus-type LANs. The Court found that the testimony of one of the inventors and the intrinsic evidence supported the SM’s claim construction. For example, the inventor had testified that he understood the term “LAN” as claimed in the patents to mean bus-type LANs. Furthermore, the Court found that the specification made clear that the claims were limited to LANs with nodes arranged as equal peers, such as those in bustype LANs.

Datapoint also argued that the claims only required that each node in a LAN have the ability to transmit and receive. The SM’s claim construction required that not only must each node have the ability to transmit and receive, but also that “each node actually use this ability at some time.” The Federal Circuit agreed with the SM, recognizing that the mere fact that a node may have the capable hardware and/or software installed would not meet this method limitation if the network system organization precluded that node from using that communication capability in actual network operation. Therefore, the Federal Circuit concluded that the district court’s adoption of the SM’s claim construction was proper and affirmed the SJ of noninfringement.