A Claim Element Is Vitiated If No Equivalent Exists In An Accused Infringing Device Based On Either The "Function-Way-Result" Or "Insubstantial Differences" Tests

In Brilliant Instruments, Inc. v. GuideTech, LLC, No. 12-1018 (Fed. Cir. Feb. 20, 2013), the Federal Circuit reversed the district court's grant of SJ for noninfringement and remanded the case to the district court.

Brilliant Instruments, Inc. ("Brilliant") filed a DJ action on GuideTech, LLC's ("GuideTech") three patents: U.S. Patent Nos. 6,226,231 ("the '231 patent"); 6,091,671 ("the '671 patent"); and 6,181,649 ("the '649 patent").  The three patents relate to circuits that measure the timing errors of digital signals.  Claim 1 of the '231 patent requires "a plurality of measurement circuits defined within said signal channel."  Claim 1 of the '671 patent and claim 1 of the '649 patent require a capacitor that is "operatively disposed in parallel with respect to said first current circuit."  The district court construed the above claim terms and entered SJ of noninfringement in favor of Brilliant for all three patents.