Microsoft Invalidates Motorola's Patent Claims Where Means-Plus-Function Limitations Were Found Indefinite

In this patent infringement action between Microsoft and Motorola, Motorola asserted certain claims of various patents against Microsoft, including claims that included "means for decoding" and "means for using" limitations. Motorola asserted that Microsoft's Windows 7 operating system and Microsoft's Internet Explorer 9 infringed the asserted claims of the patents-in-suit. Microsoft moved for partial summary judgment that the claims that included these means-plus-function limitations were indefinite under 35 U.S.C. §112.

As explained by the district court, "[a]t a high level, the Patents-in-Suit disclose systems and methods for encoding and decoding a bitstream (or sequence) of digital video data.3 (See generally '374 Patent; '375 Patent; '376 Patent.) The Patents-in-Suit explain that a picture in a digital video sequence can either be encoded as a "frame," comprising consecutives lines of the picture, or as two "fields," with the top field comprising the odd-numbered lines of the picture and the bottom field comprising the even-numbered lines of the picture. ('374 Patent at 1:42-58.) While encoding a picture in frame or field mode was done in prior art on a picture-by-picture basis (id. at 4:17-34), the summary of the invention states, "[t]he method entails encoding and decoding each of the macroblocks in each picture in said stream of pictures in either frame mode or in field mode." (Id. at 2:58-60 (emphasis added).)"

Microsoft contended that the "means for decoding" and "means for using" elements recited were invalid as indefinite because the Patents-in-Suit do not adequately describe a corresponding structure. As a result, Microsoft asked the court to grant partial summary judgment of invalidity for claims of the Patents-in-Suit using the "means for decoding" and "means for using" elements.

After discussing that both Microsoft and Motorola agreed that these phrases constituted means-plus-function claim limitations, the district court explained that "[m]eans-plus-function claim limitations must satisfy the requirements of 35 U.S.C. § 112 ¶ 2. S3 Inc. v. nVIDIA Corp., 259 F.3d 1364, 1367 (Fed. Cir. 2001). Paragraph 2 of section 112 of title 35 of the United States Code states, "[t]he specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention." 35 U.S.C. § 112 ¶ 2. Whether a claim complies with the definiteness requirement of 35...