By Jason Rantanen
Mettler-Toledo, Inc. v. B-Tek Scales, LLC (Fed. Cir. 2012) Download 11-1173-1200
Panel: Bryson, Moore (author), Reyna
In my Introduction to Intellectual Property class this week we discussed the classic tension between (1) reading the claims in light of the specification and (2) not importing limitations from the specification into the claims. In most instances the court attempts to strike a balance between these two canons (exemplified by Phillips). When means-plus-function claims are involved, however, different rules apply – as this case illustrates.
At issue in Mettler-Toledo was technology for weighing objects, such as large commercial trucks. The first of Mettler's asserted patents, No. 4,815,547, describes an individual load cell; the second, No. 4,804,052, describes a system and method for correcting weight measurements based on the location of objects on a scale. Following jury findings that the patents were not infringed and that the '052 patent would have been obvious, the district court denied Mettler's JMOL. Mettler appealed.
On appeal, Mettler challenged a key construction of the '547 patent claims: that several of the means-plus-function terms require a multiple slope integrating A/D converter, and equivalents thereof, rather than any generic A/D converter. Mettler contended that by limiting the claims in this way the district court erred by importing the structure of only the preferred embodiment into the claims.
The CAFC rejected this argument. "Our case law is clear that a means-plus-function claim limitation is limited to the structures disclosed in the specification and equivalents." Slip Op. at 7. Here, the patentee chose to disclose only a single embodiment; thus, the means-plus-function claim was necessarily limited to that embodiment. "If a patentee chooses to disclose a single embodiment, then any means-plus-function claim limitation will be limited to the single disclosed structure and equivalents thereof." Id. Nor was a single reference to an "A/D converter" in the Abstract sufficient to compel a broader structural disclosure because it was not linked to any claimed function.
Obviousness: The CAFC also affirmed the district court's denial of JMOL of nonobviousness of the '052 patent. Mettler's challenge was based on the argument that a prior art reference did not teach correcting for load position, an element of each claim of the '052. The CAFC rejected this argument, first noting that the issue of what is disclosed by a prior art reference is a question of fact, then concluding that substantial evidence supported the jury's finding as to the teaching of the 'prior art reference.
B-Tek's Cross Appeal for Sanctions: During the litigation B-Tek requested documents relating to Mettler's manufacturing capacity in order to rebut Mettler's lost profits damages claim. Although Mettler stated that it had no such documents, during trial a Mettler employee admitted that certain documents existed (a production schedule and plant diagram). Mettler further admitted that it provided some of these documents to its damages expert. The district court denied B-Tek's motion for sanctions on the grounds that the possible existence of these documents had been disclosed during a deposition, these documents were of marginal relevance, and that B-Tek could not show any harm or prejudice given that it prevailed on the issue of infringement.
On appeal, the CAFC concluded that the district court did not abuse its discretion in declining to sanction Mettler, correctly considering the relevance of the documents and the any harm to B-Tek.
Edited to clarify the first sentence.