Following on the heels of its en banc Phillips decision in which the U.S. Court of Appeals for the Federal Circuit recognized the importance of ascertaining the scope of its claims, the Court has now reviewed the extent to which the scope of a patent specification and claims must be aligned in order to satisfy the written description requirement of 35 U.S.C. § 112 ¶ 1. LizardTech, Inc. v. Earth Resources Mapping Inc, and Earth Resource Mapping Ltd., Case No. 05-1062 (Fed. Cir. Oct. 4, 2005 ) (Bryson, J.).
LizardTech’s patent concerned a computer program that used a discrete wavelet transform (DWT) to compress digital images. Because compressing images with DWT requires significant computer memory, prior art computer programs broke large images into smaller "tiles" before compressing them. These programs, however, often resulted in flawed images, including "edge artifacts" between the reconstituted tiles. The `835 patent improved on prior art by creating a "seamless DWT of the image."
LizardTech brought an action alleging that Earth Resource Mapping, Inc. (ERM) infringed certain claims. The district court held, in part, that several of the asserted claims were invalid for failing to satisfy the written description requirement of § 112 ¶ 1. LizardTech appealed.
The Federal Circuit agreed with the district court that held the challenged claims were invalid for failing to provide an adequate written description under § 112 because those claims were broader than, and unsupported by, the specification. The specification provided only "one method for creating a seamless DWT, which is to ‘maintain updated sums’ of DWT coefficients." While some of the asserted claims included this procedure, others lacked any "maintain updated sums" limitation. Thus, the Court determined the latter claim only required "taking a seamless DWT generically." Since the specification only disclosed a specific method of creating a seamless DWT, and the claims in issue covered "all ways of performing DWT-based compression processes that lead to a seamless DWT," the claims were broader than the specification.
The fact that the claim was broader than the specification did not immediately doom it to invalidity. "[I]t is unnecessary to spell out every detail of the invention in the specification; only enough must be included to convince a person of skill in the art that the inventor possessed the invention and to enable such a person to make and use the invention without undue experimentation." Nevertheless, the Court found the patent failed to meet the requirements of § 112 on both counts. First, it failed to teach a person of skill in the art how to make a seamless DWT generically. Second, a person of skill in the art "would not understand LizardTech to have invented a method for making a seamless DWT, except by ‘maintaining updated [sic] sums of DWT coefficients.’"
Practice Note
While overbreadth has long been a concern in determining the validity of patent claims, the LizardTech and Phillips cases, read together, may signal a renewed focus on interpreting claims in the context of the written patent. Practitioners should be wary of relying on material outside the bounds of the patent document and instead concentrate on ensuring the patent reflects a comprehensive and consistent description of the invention.
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