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Doctrine of Equivalents Successful Where Amendment Did Not Narrow the Claim

December 17, 2001

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Last Month at the Federal Circuit - January 2002

Judges: Mayer (author), Newman, and Bryson

In Bose Corp. v. JBL, Inc., No. 01-1054 (Fed. Cir. Dec. 17, 2001), the Federal Circuit affirmed a district court’s holding of infringement under the DOE, its exclusion of evidence, and its damages calculation.

Bose Corporation ("Bose") charged JBL, Inc. ("JBL") with infringement of U.S. Patent No. 5,714,721 ("the '721 patent") relating to porting in a loudspeaker system. "Porting" pertains to a port tube inside a loudspeaker used to radiate sound from inside the speaker at high, crisp audible levels. Bose alleged that JBL products using the "Linear A" curve or the "Exponential" curve infringed claims 1-3 of the '721 patent.

JBL asserted defenses of noninfringement and invalidity and moved for SJ of noninfringement with respect to both literal infringement and infringement under the DOE. The district court had granted JBL's motion with respect to literal infringement, but denied it with respect to the DOE. After a bench trial, the district court held the '721 patent not invalid and infringed under the DOE and awarded damages of $5,676,718. JBL appealed, arguing that the district court had erred in denying its motion for SJ under the DOE, had abused its discretion in excluding evidence, and had erred in its determination of an applicable royalty rate.

Independent claim 1 was originally filed as dependent claim 2 and recited a "boundary being defined by an ellipse." Bose contended that that limitation was met by an equivalent in JBL products. During prosecution, independent claim 1 had been objected to as being dependent on a rejected claim, but the Examiner had indicated that it would be allowable if rewritten in independent form to include all the limitations of the rejected claim on which it depended. After revision, the Examiner had then required the insertion of the phrase "having a major diameter" to provide antecedent basis for claim 3 of the '721 patent, thus complying with the definiteness requirement of 35 U.S.C. § 112, ¶ 2.

On appeal, JBL argued that the Examiner's rejection under § 112 and the subsequent insertion of the phrase "having a major diameter" narrowed the scope of the claim, thus barring Bose from obtaining any range of equivalents for that limitation. The Federal Circuit disagreed, concluding that an inherent characteristic of an ellipse is a major diameter. Thus, the insertion of that phrase during prosecution did not satisfy the "narrowing amendment" requirement of Festo.

Next, JBL argued that the district court had abused its discretion by refusing to admit a French patent application during trial on which JBL relied to demonstrate invalidity and noninfringement under the DOE. The district court had held that the French application, first offered well after the final pretrial order and on the seventh day of trial, was untimely and, in any event, lacked probative value because it disclosed a hyperbola rather than an ellipse. Applying First Circuit law, the Federal Circuit agreed, concluding that the district court's decision was not an abuse of discretion.

Finally, JBL argued that the district court had erred in its royalty-rate determination because it was based on the entire market value of the loudspeaker system incorporating the infringing element. The Federal Circuit disagreed. Although acknowledging that the claimed device comprised only a small component of the entire system, the Federal Circuit affirmed the damages award because that "small component" inextricably worked with other components of the system, contributed substantially to the large demand for the product, and was integral to the overall performance of the product. Moreover, Bose presented evidence detailing its efforts to market the benefits of loudspeakers using the device claimed in the '721 patent and the increase in sales following introduction of those loudspeakers. Accordingly, the Federal Circuit held that substantial evidence supported the district court's award of a reasonable royalty based on the entire market value of the loudspeakers.