View source for Doctrine of Equivalence Supplement: Johnston v. IVAC Corp. (JWB)

==The Case==
*Turner developed thermometer probe cover that stays on, owned by AMEC
*District Court of Southern California -- summary judgment that IVAC's thermometer probe covers do not infringe
*Summary judgment when the defendant carries of burden of "pointing out to the district court that there is an absence of evidence to support the nonmoving party's case"
**IVAC convinced court that AMEC failed to prove infringement literally or by equivalence
===Patent===
*AMEC: metal probe had sharp metal hook to keep probe cover on
*IVAC: ring on metal probe to keep probe cover on via friction (intentionally left out sharp edge to allow probe cover to be removed)

==Ruling==
*Affirmed
*<b>To establish infringement of a patent, every limitation set forth in a claim must be found in an accused product or process exactly or by a substantial equivalent</b>
===Literal Infringement===
*Mere assertion of similarity in the patented and accused devices is insufficient to create a genuine factual issue
*Where a claim does not read on an accused device exactly, there can be no literal infringement
===Section 112 (Means Plus Function)===
*An element of a claim described as a means for performing a function, if read literally, would encompass <i>any</i> means for performing the function
*Section 112 Paragraph 6 operates to cut back on the types of means which could literally satisfy the claim language
*It does not extend the element to equivalent functions
===Doctrine of Equivalents===
*AMEC does not assert a friction fit is equivalent to an inscription fit
*Instead, AMEC asserts that IVAC devices perform inscription fit with equivalent structure
**No evidence for such a claim