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Prior Art Anticipates a Functional Limitation That Is Inherent

07-1515
August 21, 2008

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Last Month at the Federal Circuit - September 2008

Judges: Bryson, Archer, Prost (author)

[Appealed from: E.D. Mo., Judge Perry]

In Leggett & Platt, Inc. v. VUTEk, Inc., No. 07-1515 (Fed. Cir. Aug. 21, 2008), the Federal Circuit affirmed the district court’s grant of SJ of invalidity that certain claims of U.S. Patent No. 6,755,518 (“the ’518 patent”) were either anticipated or obvious. Given this conclusion, the Court did not address the district court’s alternative basis for granting SJ, i.e., the claims were invalid for indefiniteness.

Leggett & Platt, Inc. and L&P Property Management Company (collectively “L&P”) own the ’518 patent. The ’518 patent discloses a method and apparatus for printing ink on a rigid, deformable substrate without causing any deformation. To print on such substrate, the ’518 patent describes the use of a “UV curable” ink, which can be cured (i.e., dried) by exposure to ultraviolet (“UV”) radiation, and a “cold UV” radiation source. Where some “hot” sources of UV radiation will emit non-UV radiation that can heat and deform the substrate, a “cold UV” radiation source can substantially cure the ink without deforming the substrate. The ’518 patent also teaches that, after the UV curable ink is deposited on the substrate, the cold UV source “freezes” the ink in place to prevent it from spreading, wicking, or otherwise moving on the substrate.

L&P sued VUTEk, Inc. (“VUTEk”), alleging that VUTEk’s PressVu UV printers infringed claims 1-3, 7, 9, 10, and 19 of the ’518 patent. The district court construed the disputed terms, and the parties filed cross-motions for SJ on infringement and invalidity. The district court granted VUTEk’s motion on invalidity and deemed the remaining issues moot. The district court found that claims 1, 9, 10, and 19 of the ’518 patent were invalid as anticipated by VUTEk’s U.S. Patent No. 6,457,823 (“the ’823 patent”) and that claims 2, 3, and 7 were invalid as obvious over the ’823 patent and VUTEk’s U.S. Patent No. 6,616,355 (“the ’355 patent”). Alternatively, the district court found that these claims were invalid as indefinite. L&P appealed.

On appeal, the Federal Circuit noted that claim 1 was representative and that it required at least one cold UV curing assembly “oriented to direct UV energy . . . to freeze dots of the jetted ink” and “effective to impinge sufficient UV light on the ink to substantially cure the ink.” Slip op. at 5 (alteration in original). The parties agreed that the UV radiation source disclosed by the ’823 patent consisted of light emitting diodes(“LEDs”), that the LEDs were “cold UV,” and that the LEDs were “oriented to direct UV energy . . . to freeze dots of the jetted ink.” L&P asserted, however, that the ’823 patent failed to teach that the LEDs were  “effective to impinge sufficient UV light on the ink to substantially cure the ink.”  The Federal Circuit disagreed.

The Court noted that the district court construed “substantially cure” to mean “cured to a great extent or almost completely cured” and that, as a result, claim 1 simply required a cold UV source (e.g., LEDs) that is “effective to impinge sufficient UV light on the ink” to cure the ink to a great extent or almost completely cure it. The Court explained that because the claim was written with functional rather than structural language, it required the cold UV assembly to be “effective to” substantially cure rather than requiring ink to be substantially cured, and that it would be anticipated so long as the LEDs disclosed in the ’823 patent were able to cure the ink to a great extent. The Court observed that the ’823 patent taught that the LEDs cured the ink 75-80% and that a reasonable mind might well find 75-80% cured to be “substantially cured” and thus conclude that the disclosed LEDs were effective to cure the ink to a great extent. The Court noted, however, that SJ can only be granted when, even if all material factual inferences are drawn in favor of the nonmoving party, there is no reasonable basis for deciding in favor of the nonmoving party. Here, the Court could not say that, as a matter of law, 75-80% cured was “cured to a great extent or almost completely cured.” Id. at 9.

Nonetheless, the Court determined that, as a matter of law, the ’823 patent inherently disclosed LEDs that were “effective to impinge sufficient UV light on the ink” to cure the ink to a great extent. It reasoned that under the principles of inherency, if the prior art necessarily functions in accordance with, or includes, the claim limitations, it anticipates. In other words, noted the Court, the ’823 patent would anticipate by inherency if its LEDs necessarily were “effective to impinge sufficient UV light on the ink to substantially cure the ink.” Id. The Court concluded that such a disclosure was inherent in the ’823 patent. It thus found that the district court did not err in finding claims 1, 9, 10, and 19 of the ’518 patent to be anticipated by VUTEk’s ’823 patent. In doing so, the Court rejected L&P’s other arguments, including its argument that LEDs werenot practical for use in printers at the time because they were too expensive. The Court explained that the fact that a technology may be impractical does not undermine an otherwise anticipatory disclosure.

The Federal Circuit then turned to the issue of obviousness and indefiniteness. It noted that while L&P also appealed the district court’s finding that dependent claims 2, 3, and 7 were rendered obvious by a combination of VUTEk’s ’823 and ‘355 patents, L&P’s argument was based on the allegedly erroneous anticipation finding. Because the Court did not perceive any error in the anticipation finding, it concluded that the district court did not err in finding claims 2, 3, and 7 as obvious. Accordingly, the Court affirmed the district court’s grant of SJ of invalidity based on anticipation and obviousness. Given this conclusion, the Court did not address the district court’s alternative basis for granting SJ, i.e., the claims were invalid for indefiniteness.