Patentee Could Not Claim All Methods for Achieving a Result - Only the Single Method Described Satisfied the Written Description Requirement

Case:Lizardtech, Inc. v. Earth Resource Mapping, Inc. , No. 05-1062 (Fed Cir. 10/4/05)

The One Sentence Summary: A claim for creating a digital wavelet transform (“DWT”) for image compression was interpreted to include the limitation “seamless” due to arguments in the prosecution history in which a group of claims were all characterized as seamless, but the claim was invalid because it did not provide an adequate written description of a generic method of creating a seamless DWT other than the one embodiment described in the specification and claimed in other claims.


What They Were Fighting About:Discrete wavelet transforms (“DWT”) are algorithms used in digital image compression. In order for less powerful computers to compress images, image compression can be done on sections or tiles of an image that are then recombined. This method has the drawback that the tiling can create visible borders around the “tiles”, degrading the image. Lizardtech had a patent for a method of creating a seamless DWT by performing calculations on adjacent tiles and using the sums to correct the tiles and remove the borders. Earth Resource Mapping used a different technique for creating a seamless DWT by performing the algorithm on one row or column at a time. The district court held that defendant did not infringe, and that one of the claims of the patent was invalid.

Federal Circuit Holdings:

• The district court properly construed the claims and granted summary judgment of non-infringement with respect to claims 1 and 13 which provided for achieving a seamless DWT through the use of updated sums taken from adjacent tiles. Defendant’s process did not use a tiling method or summing adjacent values to achieve a seamless DWT.


• Claim 21, which did not state that the DWT was “seamless”, should nevertheless be interpreted to mean “seamless” where the applicant argued to the examiner in the prosecution history that a group of claims including 21 resulted in a seamless DWT. This had an effect on the examiner who noted that claim 21 produced a seamless DWT in the reasons for allowance.


• Claim 21 was not valid under the written description requirement of 35 U.S.C. § 112 1 because it did not state a way to achieve a seamless DWT. The specification and claim 1 described only a single method of obtaining a seamless DWT, and the specification had no support for more generic methods. The claim failed to meet the written description requirement because it did not establish that the applicant had possession of a generic method of making seamless DWTs (other than the tiling process claimed by claim 1), nor did it enable one of ordinary skill in the art to create a seamless DWT without undue experimentation.


• The court made the analogy that an inventor who made one type of fuel efficient engine cannot make a broad claim for every type of fuel efficient engine, no matter how different in structure or operation.