Statement during prosecution not a clear and unmistakable disavowal, no prosecution disclaimerNovember 29, 2007

In a decision yesterday, the Federal Circuit partially reversed a district court's summary judgment of noninfringement of a patent directed to closed circuit television systems. In granting summary judgment, the district court held that the doctrine of prosecution disclaimer limited the scope of the claims, finding the inventors characterized the invention narrowly in response to an office action.The Federal Circuit disagreed, holding that there was not the necessary clear and unmistakable disavowal of claim scope necessary for prosecution disclaimer to apply. Specifically, the statement in question was contrary to the description of the invention in the specification, was inconsistent with other statements made in the same office action response, and one of ordinary skill in the art would not recognize the statement to be a clear and unmistakable surrender of claim scope, because it would result in an inoperable system. Because prosecution disclaimer did not apply "[o]n this unique amalgamation of facts," the court reversed the district court's claim construction. However, because only one of three accused products potentially infringed even under the revised, broader claim construction, the district court's summary judgment was only partially reversed.More detail of Elbex Video, Ltd. v. Sensormatic Elecs. Corp. after the jump.The patent in suit was directed to a closed circuit television system including multiple remote controlled cameras with signals going to and from the cameras. There was only one independent claim, reproduced below (emphases added):

1. A closed circuit television apparatus comprising:a plurality of remote-controlled television cameras for generating video signals, each camera including a circuit for generating 1st code signals allotted to a respective television camera;receiving means for receiving said video signals and said 1st code signals;switching means for selecting a television camera to be connected to said receiving means;said receiving means including a monitor for displaying images corresponding to the video signals received in said receiving means; andcontrolling means for controlling said television camera;said controlling means including control and code generator means for generating control signals to control said television camera and 2nd code signals corresponding to the 1st code signals received in said receiving means and for transmitting said control signals and said 2nd code signals to said television camera;each television camera further including a command circuit receiving said control signals and said 2nd code signals generated in said controlling means and operating said television camera in accordance with said control signals when said 2nd code signals coincide with a code allotted to said television camera.

The district court granted summary judgment of non-infringement for two reasons: (1) the accused system failed to meet the "addressing" claim limitations, and (2) the "receiving means" limitation was narrowed in prosecution such that this limitation was not satisfied by the accused system. The Federal Circuit first addressed claim construction of the "receiving means" limitation in view of the specification and prosecution history. During prosecution, the patentee stated, in response to an office action, that:

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 court concluded that this was not a clear and unmistakable surrender of the claim scope. The court based this conclusion on four factors:

  1. absence of support in the specification for the prosecution argument;
  2. ambiguity in the prosecution argument;
  3. defendant's technical expert didn't understand the argument (meaning one of ordinary skill in the art would not understand it to be a disclaimer); and
  4. if interpreted literally, the argument resulted in an inoperative system.

Therefore, the Federal Circuit held there was no prosecution disclaimer, and thus concluded the district court's claim construction was erroneous.The Federal Circuit then addressed the district court's first basis for summary judgment: the lack of the "addressing" limitations in the accused system. First, the court noted that there were three different systems that should each be analyzed separately, which the district court did not do. The Federal Circuit concluded that the first two systems did not meet the claim limitations, and therefore summary judgment of noninfringement with respect to those systems was affirmed. On the third system, the court held there was a disputed question of material fact, and reversed summary judgment on that system, and remanded. Judge Cote of the Southern District of New York, sitting by designation, wrote a short one-paragraph dissent, concluding that there was an unmistakable surrender of claim scope in the prosecution argument such the district court's claim construction of the "receiving means" limitation, and therefore the summary judgment of noninfringement should have been affirmed.To read the full decision in Elbex Video, Ltd. v. Sensormatic Elecs. Corp., click here.

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