Disclaimed or Not Disclaimed? That is (Still) the Question . . .

Elbex Video Ltd. v. Sensormatic Electronics Corp. (2007-1097) November 28, 2007

During litigation, the district court granted SJ of noninfringement, where part of the decision was based on prosecution history estoppel. Specifically, one claim recited:

receiving means for receiving said video signals and said 1st code signals . . .

said receiving means including a monitor for displaying images corresponding to the video signals received in said receiving means . . .

The district court found that during prosecution before the PTO, the inventor had limited the "receiving means" to a "monitor" that receives the video and first code signal. The district court concluded that "whether by mistake or otherwise," the inventor "agreed" to limit the "‘receiving means’ to a structure through which a video monitor receives the 1st code signal from a camera." This "agreement" appeared in a response to an office action.

Interestingly, the response to the office action appeared to have errors that were inconsistent with the specification and the putative operation of the disclosed device. Although the district court acknowledged that obvious errors in statements made before the PTO are not necessarily binding, it concluded that the patentee's statement was nevertheless binding, since the prosecution statements "would not have been viewed by one of ordinary skill in the art to be obvious errors."

The CAFC reversed, finding that the statements did not amount to a clear and unmistakable surrender of claim scope:

First, the statement in the prosecution history is unsupported by even a shred of evidence from the specification. The specification never suggests that the monitor of the receiving means receives first code signals and returns a corresponding code to the cameras . . . There is nothing in the specification to suggest that the first code signal ever reaches the monitor.

Second, read in isolation, the statement in the prosecution history could be argued to be a disclaimer. When the prosecution history as a whole is considered, the inventor’s response to the PTO is not as clear . . . two paragraphs after the alleged disclaimer, the inventor also included [an additional statement] to distinguish a reference relied on by the PTO examiner . . . This statement, unlike the alleged disclaimer, is fully supported by the written description and provides further indication that the earlier statement in the same document was not a clear and unmistakable surrender.

Third, reading the specification and remainder of the intrinsic record as a whole would lead those skilled in the art to the conclusion that the inventor’s statement that the monitor received the first code signals and, "based upon" that code, transmits a second code signal "back to the camera" was not a clear and unmistakable surrender of claim scope . . . This prosecution statement if taken literally would result in an inoperable system . . . Even Sensormatic’s own technical witness testified that he "ha[d] trouble figuring out how [transmitting the code signals to and from the monitor] would work."

AFIIRMED-IN-PART, REVERSED-IN-PART, and REMANDED

Judge Cote's Dissent (sitting by designation):

I believe that when the prosecution history and the patent are considered together, the evidence is clear and unambiguous that Elbex’s reference to a "monitor" in its response to the PTO Office Action was a strategic choice and an unmistakable surrender of claim scope. Elbex made significant revisions to Claim 1 in what became the ‘085 patent in order to obtain the patent, and is now trying to recapture what it chose to abandon in the proceedings before the PTO. I would affirm.