Federal Circuit Says Patent Preamble Not Limiting
By Debbie Rosenbaum – Edited by Jad Mills
Marrin v. Griffin, Appeal 2009-1031 (Fed. Cir., Mar. 22, 2010)
On March 22, 2010, the Federal Circuit affirmed the district court’s summary judgment that U.S. Patent No. 5,154,448, which related to a beverage cup scratch-off label, was invalid because it was anticipated under 35 U.S.C. § 102(b).
Judge Dyk, writing for the majority held that the use recited in the preamble, namely that the scratch-off label was “for permitting a user to write thereon without the use of a marking implement.” was not to be treated as a claim limitation. In finding that this use statement in the preamble was not limiting, the court noted that “use descriptions such as this are rarely treated as claim limitations.” The court held that “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 other description is also part of the claim.” Because the preamble was not limiting, the patent owner could not use it to distinguish the patent from the prior art, thus allowing the court to invalidate the patent under section 102(b).
Inventive Step and Patent Hawk both offer good overviews of the case. Patent Case Review provides a summary of the legal issues. Gary Odom of Patent Hawk argues that “Judge Newman got it right, which is to say that this nicely self-contained issue is ripe for en banc review. The inconsistent treatment of preambles begs for clarity.”
U.S. Patent No. 5,154,448 related to using a scratch-off label to mark beverage containers and cups so that attendees of a gathering or party could keep track of their beverage cups. While the patentees admitted that the prior art disclosed various scratch-off devices, they contended that the prior art did not disclose scratch-off labels “for permitting a user to write thereon without the use of a marking implement”, as stated in the preamble of the claims. The court ruled that the “for permitting” language was not a claim limitation as it only added a statement of a purpose or an intended use for the invention and the patentees did not demonstrate clear reliance on the preamble during prosecution to distinguish the claimed invention from the prior art. In holding as it did, the court reasoned that a patent claim’s preamble should not generally be used in interpreting the scope of the claim.
During prosecution, the patentees explained to the examiner, while amending the claims to their current form, that “‘writing means’ is not an element of Applicant’s claims, and does not appear in the new claims.” The court explained that while “[c]lear reliance on a preamble during prosecution can distinguish a claimed invention from the prior art and render the preamble a claim limitation . . . there was no such reliance here.” The court was also not swayed by the fact that the body of the claim relies on the preamble term “label” in order to make sense: “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 other description is also part of the claim.” Because the applicants “expressly attested that the ‘writing means’ language was not a claim limitation, they cannot now assert that it was such a limitation.” The court therefore affirmed the district court decision.
Judge Newman dissented, stating that “[t]he majority’s excision of the very portion of the claim that distinguishes the invention from the prior art, only to invalidate the claim on the basis of that prior art, is contrary to law.” Judge Newman went on to describe how the patentees distinguished prior art in their patent specification and noted that such differences “are ignored by my colleagues . . . [the majority] instead engrafts a meaning on the claim that the inventors did not present and the Patent Office did not examine.”
This case reminds patent applicants about the importance of clearly including all the limitations of the invention in the body of the claim. Additionally, the disagreement between the majority and the dissent demonstrates how easily an outcome of patent validity or invalidity can vary depending on seemingly minor applications of claim construction doctrines.