In an opinion focusing on the construction of the preamble of a claim, the Federal Circuit recently affirmed a district court’s finding of invalidity of the patent at issue in Marrin et al. v. Griffin, No. 2009- 1031 (Fed. Cir. Mar. 22, 2010), and held that “use descriptions [in the preamble] of a claim are rarely treated as claim limitations.”  

Appellants Jeffrey and Claudia Griffin (the Griffins) appealed the judgment of the U.S. District Court for the Central District of California. The district court granted summary judgment of invalidity, finding the Griffins’ United States Patent No. 5,154,448 invalid under 35 U.S.C. § 102(b) as anticipated by the prior art. In a majority opinion written by Judge Dyk (and over a dissent opinion written by Judge Newman), the Federal Circuit reiterated that “[f]or apparatus claims, . . . generally patentability ‘depends on the claimed structure, not on the use or purpose of that structure[,]’ [but] [c]lear reliance on a preamble during prosecution can distinguish a claimed invention from the prior art and render the preamble a claim limitation.”  

In the Marrin case, the claimed invention involved the use of a scratch-off label to mark beverage containers and cups. In particular, claims of the patent at issue included language in the preamble of one claim that recited “a use of the claimed invention.” In particular, some claims recited a scratch-off label “for permitting a user to write thereon without the use of a marking implement” in the preamble (emphasis added). The district court had found that the “‘preamble language is not limiting’.” Without the language in the preamble serving as a limitation, the claim was therefore broader in scope and the district court thereby concluded that “‘a person of ordinary skill in the art at the time of the invention would find that the limitations of the body of the claims of the . . . patent are anticipated by one or more of’” the prior art references related to scratch-off devices.  

On appeal, the Griffins’ primary contention was that the district court improperly failed to treat the “for permitting” language recited in the preamble as a claim limitation. The Federal Circuit agreed with the district court’s finding that the preamble is not limiting because (1) the language in the preamble “only added an intended use,” and (2) the prosecution history did not indicate a clear reliance on the preamble language for distinguishing the invention over the prior art. In addition, during prosecution the applicants attested that the preamble language was not, in fact, limiting.  

Judge Dyk addressed Judge Newman’s argument that the “presumption against reading a statement of purpose in the preamble as a claim limitation is inapplicable because the body of the claim makes no sense without the preamble’s reference” to a specific claim term. In response, Judge Dyk reasoned that this fact was also true in other cases and “the mere fact that a structural term in the preamble is part of the claim does not mean that the preamble’s statement of purpose or description is also part of the claim.”  

A copy of the opinion can be found at