In Sound View Innovations, LLC v. Hulu, LLC, No. 2021-1998 (Fed. Cir. May 11, 2022), the Federal Circuit affirmed the district court’s claim construction, but vacated the district court’s grant of summary judgment and remanded for further proceedings.

Sound View accused Hulu of infringing U.S. Patent No. 6,708,213, which claims methods for improving the caching of streamlining multimedia data from a content provider to a user’s computer. The parties disputed the construction of the downloading/retrieving limitation. Hulu, relying on the prosecution history, argued that the concurrent downloading/retrieving must involve the same buffer. The district court agreed, finding that the applicants’ statements during prosecution limited the claim to concurrent downloading from and filling of a single buffer. Based on the court’s claim construction, Hulu moved for summary judgment, which the district court granted.

On appeal, the Federal Circuit agreed that the prosecution history establishes that the downloading and retrieving actions must involve the same buffer. The Court first noted that neither the claim language nor the remainder of the specification established a plain meaning contrary to the meaning established by the prosecution history. The Court then found that the applicants’ statements during prosecution distinguished the claimed invention from the prior art based on the concurrent use of a single buffer rather than serial use.