Court Opinion

ID: 7084437
Source: CourtListenerOpinion
Date Created: 2022-07-24 10:38:18.387374+00
Date Added: 2024-06-11T16:12:56.853712
License: Public Domain

SCHALL, Circuit Judge,
eoneurring-inpart and dissenting-in-part.
The majority vacates the district court’s grant of summary judgment that the defendants’ device did not infringe, either literally or by equivalents, U.S. Patent No. 4,604,501 (the “ ’501 patent”) and remands the case for further proceedings. I agree with the majority’s construction of the term “disabling” in the asserted claims. However, I believe that, under that con*879struction, the defendants, as a matter of law, cannot infringe the ’501 patent.
The majority construes the term “disabling” in the asserted claims to mean “to make incapable or ineffective,” but not simply “to weaken.” Majority, op. at 876. The majority then concludes that there are genuine issues of material fact regarding infringement of this claim limitation. Id. at 877-78. The majority points out that Doorking presented evidence that when the defendants’ device’s tenant bias potentiometer is at its maximum bias setting, the device “disabl[es]” the second, exterior microphone, when a tenant speaks on the first, interior, microphone because under those circumstances, in normal operation, any noise at the second microphone cannot be heard by the tenant. Id. at 877.
The majority is correct that Doorking presented evidence, through its expert Dr. Myron Kayton, that in the accused device, the tenant bias potentiometer, in conjunction with an attenuator, prevents any noise at the second microphone from being heard by a tenant when the tenant is speaking on the first microphone. However, the claims at issue require “disabling [the] second microphone such that transmission cannot occur though said second microphone when audible sounds are generated at [the] first microphone____” ’501 patent, col. 10, II. 17-20. The claims require the second microphone to be disabled, i.e., incapable or ineffeetive-not merely weakened, “such that transmission cannot occur through said second microphone.” Id., col. 10, II. 18-19.
The accused system never prevents transmission from the second microphone; it merely attenuates the output of the second microphone when the tenant is speaking so that the output cannot be heard through the tenant’s speaker. Dr. Kayton stated that the accused device uses an attenuation circuit “to prevent the visitor from being heard as long as the tenant speaks.... ” Dr. Kayton agreed with the defendants, however, that their device allows the second microphone to “operate[ ] at all times,” even when noise is detected at the first microphone. Dr. Kayton stated that, in the accused system, the second microphone is always “operative,” and that “when the visitor speaks, there is a voltage output at the visitor’s microphone, but if the tenant is speaking that voltage output cannot be perceived by the tenant.” It may be true that, in the accused device, the second microphone, as Dr. Kayton noted, “is effectively ‘disabled’ when the tenant is speaking.” Dr. Kayton acknowledged, though, that there is still an electrical output from the second microphone when the tenant speaks. Significantly, Doorking presented no evidence that suggested that the accused device was even capable of “disabling” the second microphone so that “transmission cannot occur through [the] second microphone,” as recited in the claims. The accused device weakens the signal transmitting from the second microphone through the use of an attenuator, but it never makes the second microphone “incapable or ineffective” of transmitting a signal when “audible sounds are generated at [the] first microphone.” Thus, the accused device cannot be found to literally infringe the ’501 patent.
I also believe that Doorking is estopped from asserting that the defendants’ device infringes the ’501 patent under the doctrine of equivalents. We noted in Bayer AG v. Elan Pharm. Research Corp., 212 F.3d 1241, 1252-53, 54 USPQ2d 1711, 1719 (Fed.Cir.2000), that statements made during prosecution can evince a clear and unmistakable surrender of subject matter that cannot be recaptured through the doctrine of equivalents. During prosecution *880of the ’501 patent, the inventors, in response to a prior art rejection, described the claimed invention as “literally deactivat[ing]” the second microphone when sound was present at the first microphone. In addition, the inventors distinguished a prior art reference, the Nashino reference, on the ground that Nashino “does not cut off a microphone or a speaker at any time. In other words, the microphone and speaker are always on.” Such statements evince a clear surrender of devices that leave the second microphone on when the tenant is speaking, systems that do not “literally deactivate[]” or “cut off’ the second microphone. As acknowledged by Doorking’s expert, the accused device’s second microphone is on at all times. The accused device thus falls within the scope of the surrendered subject matter. It therefore cannot infringe the ’501 patent under the doctrine of equivalents.
For the foregoing reasons, I respectfully dissent from the majority’s vacatur of the grant of summary judgment of non-infringement. I would affirm the grant of summary judgment. However, like the majority, I would affirm the district court’s denial of the request for attorneys’ fees and costs.