The Federal Circuit recently limited construction of patent claims to a scope supported by intrinsic evidence of embodiments disclosed in a patent specification. Ruckus Wireless, Inc. v. Innovative Wireless Solutions, 2016 U.S. App. LEXIS 9786 (Fed. Cir. May 31, 2016). In a 2-1 decision, the panel upheld the district court’s construction of the asserted claims, which limited the scope of key terms based on embodiments described in the specification. The district court decision resulted in a declaratory judgment of non-infringement.
Innovative Wireless Solutions (“IWS”) owns patents (U.S. 5,912,895, 6,327,264, 6,587,473) that are directed to communicating between two modems with a LAN over telephone lines for a collision avoidance scheme. The patents describe the system using physical wires, making no mention of wireless communication, but the claims recite a connection via a “communications path.” IWS argued that off-the-shelf WiFi equipment sold by Ruckus Wireless (“Ruckus”) embodied the claimed “communications path,” and Ruckus responded by filing for a declaratory judgment of invalidity and non-infringement in the Western District of Texas. Ruckus at *2-*4. The central dispute was whether the recited “communications path” is limited to wired communication or reads on wireless communication.
The district court construed “communications path” as limited to wired communication. Id. at *5. In view of the specification, the district court found that the asserted patents were focused solely on long-distance communication over wired communication paths. That is, the district court relied solely on intrinsic evidence for its claim construction. The parties then stipulated jointly to a final judgment of non-infringement based on this claim construction. IWS appealed, disputing the district court’s construction that limited the claims to wired communication.
Reviewing claim construction de novo, the Federal Circuit held that one of ordinary skill in the art at the time of the invention would not have understood the plain meaning of “communications path” to include wireless communications. Because the specification described wired communications, particularly telephone wires, in such detail, the intrinsic evidence showed that the patents were directed to wired communications. Further, IWS “did not present—nor did the district court consult—any extrinsic evidence” to show that “communications path” was understood to include wireless communications. Id. at *8. Further still, because the specification lacked mention of wireless communications, and when “a claim is ambiguous, it should be construed to preserve its validity,” the Court stated that including wireless communications in “communications path” “would likely render the claims invalid for lack of written description.” Id. at *9.
Judge Stark (Chief Judge of the District of Delaware, sitting by designation), dissenting, would have vacated the district court’s construction and remanded for presentation of extrinsic evidence. Id. at *12. Judge Stark argued that Ruckus never disputed that the plain and ordinary meaning of “communications path” included wireless communications, but argued that the specification required a narrower construction. Id. at *14. As a result, Judge Stark argued that fact-finding would be necessary to determine the plain and ordinary meaning of the term “communications path” given its apparent ambiguity. Further, the dissent argues that the absence of an express disclaimer should support including wireless communications in “communications path.” Id. at *22.
The takeaway here is that intrinsic evidence can limit claims by what it does not include, as well as by limiting definitions and explanations. Regardless of whether Judge Stark was correct to suggest a remand inviting extrinsic evidence, litigants may wish to consider whether the intrinsic evidence adequately supports their position, and whether even in light of the bias against extrinsic evidence flowing from the Phillips case, extrinsic evidence should be put in the record.