Flawed Testing Fails to Prove Infringement

ADC Telecommunications, Inc., v. Switchcraft, Inc., [2007-1423, -1525] (June 16, 2008) [SCHALL, Prost, Ward] NON-PRECEDENTIAL The Federal Circuit affirmed judgment following a jury trial that defendant Switchcraft did not infringe U.S. Patent No. 6,045,378 on a a switching coaxial jack device that utilizes inwardly projecting fins to provide improved impedance matching between the jack and its connected cables
BRIEF: The case turned on the test for determining whether a claim limitation was met ADC introduced evidence comparing the impedance matching in Switchcraft’s accused devices with and without the waveguides and projections, to demonstrate that the presence of those structures improved impedance matching. Switchcraft countered with test results generated by an alternative method, and also argued that ADC’s testing method was flawed because it did not remove the fins’ surrounding slots, which themselves, Switchcraft contended, affected impedance matching. Thus, according to Switchcraft, ADC’s test results reflected the combined effects of both fins and slots on impedance matching, and did not properly isolate the effect of fins alone.
LOF: Infringement is a question of fact, reviewed for substantial evidence when tried to a jury. Substantial evidence is “such relevant evidence as a reasonable mind might accept as adequate to support a conclusion.” Plaintiff asserted that the testing method required by the claims was a matter of law, which should be reviewed de novo. However, the specification lacked any clear indication that a particular testing method is required. Because the claim language does not require a particular form of testing, this inquiry is not a claim construction question, which the Federal Circuit reviews de novo, but a question of fact.
The Federal Circuit found that there was substantial evidence, in defendant's own testing and criticism that plaintiff’s testing did not isolate the source of the improvement of impedenance matching, to support the verdict, and affirmed.