No Prosecution Disclaimer for Inoperable and Unsupported Remarks

In Elbex Video v. Sensormatic Electronics (November 28, 2007), the U.S. Court of Appeals for the Federal Circuit concluded 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."

According to the opinion by Circuit Judge Moore:

. . . This prosecution statement if taken literally would result in an inoperable system. Even if the monitor contained the necessary hardware to receive and generate a second code signal corresponding to the first code signal to be sent back to the cameras (a technological concept not at all supported by the specification), the second code signals would not reach the cameras. The low pass filter is positioned between the monitor and the cameras. The sole purpose of that filter is to "prevent the high frequency output signals [i.e., the "second code signals"] of the controller device 14 from passing." ’085 patent, col.5 ll.55-58. Hence, the second code signal would be filtered out before it ever reached the camera. 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."

For a prosecution statement to prevail over the plain language of the claim, the statement must be clear and unmistakable such that the public should be entitled to rely on any "definitive statements made during prosecution." Omega, 334 F.3d at 1324. On this unique amalgamation of facts, including (1) the absence of support in the specification or drawings for a monitor that receives code signals from and returns code signals to the cameras; (2) the ambiguity created by other statements in the same prosecution document; (3) the fact that Sensormatic’s own technical witness did not understand how the system would operate consistent with the erroneous statement; and (4) the inoperability of a device constructed in accordance with the incorrect statement, we conclude that this is not a case of prosecution disclaimer. One of skill in the art would understand the claim to cover a receiving means (not limited to a monitor) for receiving the video signals and the first code signals.

. . . In the present case, the district court found that the inventor limited the "receiving means" that receives the first code signal to a "monitor" that receives the first code signal. Implicit in its determination is a finding that the inventor clearly and unmistakably surrendered any claim scope between the "receiving means" that receives first code signals as expressly recited in the claims, and a "monitor" that receives first code signals. We cannot agree. The statements to the effect that the code signal is received by the monitor 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. Figure 1 above shows that the first code signal would be received by the receiving means 16 on an input line from the transmitter and then would travel to the controlling means 14. After receiving the first code signal, the controlling means decodes and manipulates the first code signal and then generates the second code signal which is transmitted back to the camera along with the control signals via the receiving means. See, e.g., ’085 patent, col.1 ll.62-67; col.2 ll.32-36; col.2 ll.39-42. As Figure 1 shows, the receiving means receives the first code signal, but the monitor does not. 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. . . In this case, two paragraphs after the alleged disclaimer, the inventor also included the following statement to distinguish a reference relied on by the PTO examiner:

The Bellman reference fails to suggest that the code received by a display device is sent back to the camera along with the control signal and that the camera is operated by control signals only upon the coincidence of the original camera code with the code returned to the camera.

The specification equates the "display device" and the "receiving device." See ’085 patent, col.3 l.4 (". . . a displaying device or receiving device 16 . . ."). 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. Amendment & Remarks at 5-6. This prosecution statement if taken literally would result in an inoperable system. Even if the monitor contained the necessary hardware to receive and generate a second code signal corresponding to the first code signal to be sent back to the cameras (a technological concept not at all supported by the specification), the second code signals would not reach the cameras. The low pass filter is positioned between the monitor and the cameras. The sole purpose of that filter is to "prevent the high frequency output signals [i.e., the "second code signals"] of the controller device 14 from passing." ’085 patent, col.5 ll.55-58. Hence, the second code signal would be filtered out before it ever reached the camera. 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."

But dissenting District Judge Cote (sitting by designation) was unconvinced:

I respectfully dissent. 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.