Homework 8: Clear Example of Doctrine of Equivalents

Kustom Signals, Inc. v. Applied Concepts, Inc.
264 F.3d 1326
CAFC, Kansas (2001)

Kustom Signals held a patent for a multimode traffic radar system which will show either the fastest speed or the strongest signal. Three of the claims used the word "or" in their wording. Kustom claimed that the "or" was a logical operator meaning one, the other, or both. Applied Concepts had designed a radar system which returned both the fastest speed and the strongest signal. The Court held that the word "or" was to hold its traditional, customary meaning as being exclusive, not inclusive, of the two statements.