Claim Construction and the Power of Preferred Embodiments

by Dennis Crouch

The Federal Circuit’s decision in Broadcom v. Netflix revolves around the construction of the claim term “drive server” found in Broadcom’s U.S. Patent No. 6,341,375.  The decision reaffirms the significance of preferred embodiments in claim construction and their potential to shape the validity of patent claims.

The basic question in the case is whether a “drive server” requires computing capabilities, or is storage capacity enough.  Although the plain language of “server” suggests computing capacity, the court agreed with the PTAB that the intrinsic evidence, including the claim language and the specification, supported the broader interpretation.  In the IPR, Broadcom was seeking the narrower construction in order to avoid prior art.  Under the broader construction, the claims were found invalid as obvious.

The important part of the case serves as a reminder of the power of “preferred embodiment” language within the patent specification.  In this case, Qualcomm had included a preferred embodiment of a DVD drive server, also known as a disk library, that contained a number of DVD drives and associated disks.  Broadcom admitted that its proposed construction would exclude this preferred embodiment if the disk library contained no additional computer.  On appeal, the Federal Circuit quoted Vitrionics in its conclusion that: Claim constructions that exclude a preferred embodiment are “rarely, if ever, correct and would require highly persuasive evidentiary support.”  Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1583 (Fed. Cir. 1996) (opinion by Judge Michel). In this case, that evidentiary support was lacking.  Invalidity affirmed.

Since Vitrionics, the Federal Circuit has placed additional weight upon intrinsic evidence — something that seemingly should give the recited principle even more power.