01/18/2010 09:29:41 AM EST
Sung on the What's Not Indefinite Under 35 U.S.C. Sec. 112
A determination that a patent claim is invalid for failure to meet the definiteness requirement of 35 USCS § 112 is a legal conclusion, and indefiniteness, therefore, like claim construction, is a question of law that the Federal Circuit reviews de novo. As Ultimax Cement Mfg. Corp. v. CTS Cement Mfg. Corp., 587 F.3d 1339 (Fed. Cir. 2009) shows, the complexity of the patent description can lead one astray regarding the definiteness of the claims. In this Analysis, Lawrence Sung analyzes Ultimax and its implications. He writes:
(1) What Was Ultimax?
On December 3, 2009, the Federal Circuit affirmed-in-part, dismissed-in-part, vacated-in-part, reversed-in-part, and remanded the district court's summary judgment of noninfringement, invalidity, laches, and indefiniteness relating to certain claims of U.S. Patents No. 4,957,556, No. 6,113,684, and No. 6,406,534, which related to rapid-hardening, high-strength cement.
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In finding the '556 patent not infringed, the district court first construed the claim term “soluble CaSO4 anhydride.” The district court defined “anhydride,” primarily using a dictionary, as “a compound formed from an acid by removal of water.” The district court reasoned that, if the claim drafter had intended to refer to calcium sulfate from which water has been removed, which was Ultimax's interpretation, it would have used the term “anhydrous CaSO4 ” or “anhydrite,” which is a specific term for anhydrous calcium sulfate. The district court acknowledged the observation of the neutral court-appointed expert, Dr. Seible, that 'given the context in which “anhydride” is used in the '556 patent, claims 9-11, it is not unreasonable to assume that the author meant anhydrite and not anhydride. However, the district court decided that the specification did not redefine “anhydride” or alter its ordinary meaning, which would require an acid. Even though one skilled in the art might realize that the drafter intended the claim to refer to “anhydrite” instead of “anhydride,” the district court held that it could not substitute terms, as that would constitute redrafting the claims, which was forbidden even when the failure to substitute terms would lead to a strange result. Thus, according to the district court, the claim term “soluble CaSO4 anhydride” required that the compound include not only calcium sulfate, but also an acid from which water has been removed. Because CTS's cement did not contain an acid from which water had been removed, the district court granted summary judgment of noninfringement.
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In beginning its analysis, the Federal Circuit reminded that under 35 U.S.C. § 112, second paragraph, the “specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention,” which is known as the definiteness requirement. Claims are considered indefinite when they are not amenable to construction or are insolubly ambiguous. Thus, the definiteness of claim terms depends on whether those terms can be given any reasonable meaning. Indefiniteness requires a determination whether those skilled in the art would understand what is claimed. The purpose of the definiteness requirement is to ensure that the claims, as interpreted in view of the written description, adequately perform their function of notifying the public of the scope of the patentee's right to exclude.