Neff Instrument Corp. v. Cohu Electronics, Inc.

This is an appeal and a cross-appeal from an action brought in the Uniied States District Court by plaintiff 1 for infringement of United States Letters Patent No. 2,832,848 by defendant. In a prior appeal 2 this court reversed the entry of a summary judgment by the district court. After a supplemental complaint had been filed and answered, the case was tried and the district court entered a judgment holding the patent valid but not infringed. No issues here involved were present in the prior appeal. Plaintiff appeals from the district court’s holding that the patent was not infringed. Defendant appeals from the district court’s holding that the patent was valid in law.

Jurisdiction in the district court was found upon Sections 1338(a) and 1400 (b) of Title 28 United States Code. This court has jurisdiction to review the judgment entered by the district court by virtue of Sections 1291 and 1294 of Title 28 United States Code.

The facts are the same for both appeals. The patented device is an electrical signal amplifier which is especially useful in instrumentation systems in which relatively weak signals representing physical phenomena such as temperature, pressure, stress, and…