Bose Corp v Lightspeed Aviation, Inc., Civil Action No. 09-10222-WGY, Memorandum and Order (D. Mass April 26, 2010) (Young, D.J.) [Claim Construction].

Plaintiff Bose Corp. (“Bose”) filed suit against Defendant Lightspeed Aviation, Inc. (“Lightspeed”) alleging that Lightspeed’s Zulu ANR Aviation headsets infringe U.S. Patent No. 5,181,252, entitled “High Compliance Headphone Driving” (the “’252 patent”). The District Court (Young, D.J.) settled claim construction disputes regarding the ’252 patent.

The first claim construction dispute concerned the meaning of “rear cavity.” Lightspeed argued that the rear cavity is an enclosure within and separate from the enclosure of the earcup that is attached to the rear of the baffle and encloses the driver. Bose argued that the rear cavity is the cavity within the earcup that is farthest from the user. The Court found that the construction of the “rear cavity” depended upon the meaning of “earcup wall.” Lightspeed interpreted the “earcup wall” to be the outer lining of the headphone structure, but Bose interpreted the earcup wall to be the whole area behind the baffle and rear cavity. The Court began its analysis by looking at the language of the claim and the patent specification. Contrary to Lightspeed’s argument, the Court found that both the claim language and patent specification supported the notion that there were only two cavities—the front and the rear—within the earcup. The prosecution history and extrinsic evidence confirmed this interpretation. Consequently, the court construed “rear cavity” as “the cavity within the headphone cup structure that is farther from the user and attached to the rear of the baffle.”

The next claim construction issue concerned the term “limiting structure” in claim 2 of the ’252 patent. Lightspeed argued that “limiting structure” is a means-plus function term subject to 35 U.S.C. § 112, paragraph 6, and must be “construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.” Because the term “means” is not used in claim 2, Lightspeed had the burden of proving that the term “limiting structure” does not recite a “sufficiently definite structure.” The parties presented expert witnesses, which disagreed about whether “limiting structure” is a term understood by “a person of ordinary skill in the art in question at the time of the invention.”

The Court found that the experts cancelled each other out and examined other intrinsic and extrinsic evidence. This examination led to the conclusion that the claims were not in fact means-plus-function claims.

The final claim construction dispute surrounded the term “means for recovering from collapse of the diaphragm” in claim 5. The dispute was whether “means for recovering” includes “raised points” for preventing collapse of the diaphragm. The court looked to the claim language and found that claim 5 addresses indentations while claim 6 addresses raised points. The differences between claims 5 and 6 demonstrated that each claim is meant to solve diaphragm collapse by different means, so the court did not include “raised points” in its construction of “means for recovering from collapse of the diaphragm” in claim 5.