On August 6, 2013, the Federal Circuit issued a 48-page opinion in 3M Innovative Props. Co. v. Tredegar Corp., in which it dissected in excruciating detail the construction of patent claims directed to "elastomeric laminates" used in diapers and exercise pants. Reading only Judge Reyna's majority opinion, one might think that the Court had merely engaged in a routine claim construction exercise, but the case gets more interesting when one reads the concurring and dissenting opinions. In particular, Judge Plager's concurrence reflects a frustration on the part of the judiciary with imprecise patent drafting, and encourages courts to construe ambiguous claims against the patent holder.

The panel was divided over how to construe the term "continuous microtextured skin layer over substantially the entire laminate," which, despite appearing repeatedly in the claims, was not explicitly defined in the specification. The district court concluded that the term should be read to require that the microtexturingand the skin layer be "continuous" across "substantially the entire surface area of the laminate." 3M (the patent holder) argued that "continuous" only modified "skin layer," and that the microtexturing need only cover a limited portion of the laminate.

While Judge Reyna adopted the district court's construction, and Judge Plager's concurrence took the discussion in entirely different direction. In his view, the case was reflective of a deeper problem with the way that patents are drafted and examined. His concurrence states:

"when claims are larded with terms such as 'substantially,' 'preferentially,' and 'relatively,' and when it takes four judges and some seventy pages of densely written opinions to find meaning in these terms, there is considerable evidence of a failure by the claim drafters to be clear and precise, and, beyond that, of a shortcoming in the patent examination process that permits claims to be so drafted. Sometimes such ambiguity is the result of sloppy drafting, and sometimes it appears that claims are drafted with a degree of indefiniteness so as to leave room to later argue for a broad interpretation designed to capture later-developed competition. The problem is exacerbated when, as here, there is a conflicting or indeterminate written description and prosecution history with regard to the claim terms at issue. Claim construction then becomes a game of crystal ball gazing, not resolved until this court's gaze is announced."

Judge Plager noted that for all the length and detail of the patents' specifications, "'continuous microtextured skin layer' does not appear one single time in the written description," despite the fact that it is used "nine times in the first eight claims." In such circumstances, Judge Plager argued that the claim should either be invalidated as indefinite, or construed against the patent holder. He pointed to Athletic Alternatives, Inc. v. Prince Mfg., Inc., 73 F.3d 1573, 1581 (Fed. Cir. 1996) as at least supporting the proposition that a narrow claim interpretation should apply when the specification does not supply a reason to adopt the broader reading. Ultimately, Judge Plager analogized the patent applicant to a tort claimant with the "last clear chance...to avoid this kind of unnecessary claim construction game," and voted "in favor of a competitor who should not have the risk of guessing wrong about what a claim term could possibly mean."

While Judge Plager did not speak for the majority, he appears to have given voice to a universal frustration of patent judges, and it is likely that district courts will consider his opinion when debating whether to adopt narrow claim constructions. Judge Plager's concurrence may provide persuasive ammunition to those trying to invalidate or construe imprecise claims terms in the future.

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