Comark Communications, Inc. v. Harris Corp.

• Decision Date: 09 September 1998
• Docket Number: No. 97-1537,97-1537
• Citation: 48 USPQ2d 1001,156 F.3d 1182
• Parties: COMARK COMMUNICATIONS, INC., Plaintiff-Appellee, v. HARRIS CORPORATION, Defendant-Appellant.
• Court: U.S. Court of Appeals — Federal Circuit

Page 1182

156 F.3d 1182

48 U.S.P.Q.2d 1001

COMARK COMMUNICATIONS, INC., Plaintiff-Appellee, v. HARRIS CORPORATION, Defendant-Appellant.

No. 97-1537.

United States Court of Appeals Federal Circuit.

Sept. 9, 1998.

A. Lee Bentley, III, Hogan & Hartson L.L.P., Washington, D.C., argued for plaintiff-appellee. With him on the brief were David A. Kikel and David G. Leitch. Of counsel on the brief were G. Franklin Rothwell and Vincent M. DeLuca, Rothwell, Figg, Ernst & Kurz P.C., Washington, D.C.

Donald R. Dunner, Finnegan, Henderson, Farabow, Garrett & Dunner, L.L.P., Washington, D.C., argued for defendant-appellant. With him on the brief were J. Michael Jakes, and Scott A. Herbst. Of counsel on the brief were Douglas E. Whitney, Donald F. Parsons, Jr. and J. Andrew Huffman, Morris, Nichols, Arsht & Tunnell, Wilmington, Delaware.

Before NEWMAN, SCHALL, and GAJARSA, Circuit Judges.

GAJARSA, Circuit Judge.

DECISION

Harris Corporation (Harris) appeals the judgment of the United States District Court for the Eastern District of Pennsylvania, holding Harris liable for willfully infringing claims 1 and 14 of U.S. Patent No. 5,198,904 (the '904 patent) assigned to Comark Communications, Inc. (Comark). See Comark Communications, Inc. v. Harris Corp., 47 USPQ2d 1469 (E.D.Pa.1998) (awarding costs and attorneys' fees); Comark Communications, Inc. v. Harris Corp., No. 95-CV-2123, 1997 WL 431000 (E.D.Pa. July 17, 1997) (denying Harris's renewed motion for judgment as a matter of law (JMOL) and granting increased damages in light of the jury's finding of willfulness); Comark Communications, Inc. v. Harris Corp., No. 95-CV-2123, 1997 WL 87260 (E.D.Pa. Feb. 24, 1997) (claim construction). Because the district court did not err in construing claim 1 of the '904 patent, and because substantial evidence supports the jury's findings of infringement and willfulness, we affirm the decision of the district court.

BACKGROUND

Comark makes and sells ultra-high frequency (UHF) television transmission equipment. Conventional television signals contain two primary components: the video portion of the signal and the audio portion. In the early and mid-1980s, most high-power UHF television transmitters used separate hardware devices to amplify the video and audio signals for transmission. In the late 1980s, Comark developed an amplification system that operated in "common amplification" mode. Comark's common amplification mode allowed the video and audio signals to be combined before amplification and amplified together in the same amplification tube. By using the common amplification technique, the Comark system was able to reduce the amount of hardware required to perform the amplification, increase efficiency, and provide a built-in redundancy to those customers using a multi-tube system. The common amplification technique, however, suffered from cross-modulation problems that produced distortions known as H sync spurs that disrupted the audio portion of the signal.

The H sync spurs caused two problems. First, the primary H sync spur occurred at the frequency of 15.734 kHz that is used for transmission of the Broadcast Television System Committee stereo pilot, which indicates to television sets that the audio signal is being broadcast in stereo. As a result, this H sync spur sometimes caused false and intermittent triggering of the stereo processing circuitry in televisions tuned to the UHF signal. Second, the sum total of the H sync spurs could increase the overall modulation of the audio carrier to a level that exceeds regulatory limits.

Comark corrected the H sync spur problem with a circuit that uses a sample of the transmitter's video signal to "precorrect" the audio signal, thereby canceling the effects of cross-modulation. Comark filed a patent application for this invention on February 25, 1991 which issued as the '904 patent on March 30, 1993. The '904 patent is entitled "Aural Carrier Correction System and Method." In this appeal, only claims 1 and 14 are at issue. They read as follows:

1. An aural carrier correction system for a common amplification television transmitter which amplifies both an aural signal and a visual signal simultaneously, the transmitter including at least a IF vision modulator for receiving a video signal and for outputting the visual signal, the system comprising:

a video delay circuit for receiving and delaying the video signal to provide a delayed video signal;

a complimentary [sic] non-linear amplifier for receiving the delayed video signal and for separately and controllably generating a non-linear amplitude domain video signal and non-linear phase domain video signal; and

an amplitude and phase modulator for receiving the aural signal and for amplitude and phase modulating the aural signal using the non-linear amplitude domain video signal and the non-linear phase domain video signal, respectively, to generate a modified aural signal; and

an adder circuit for adding the modified aural signal to the visual signal outputted by the IF vision modulator to reduce unwanted noise appearing at specific frequencies in an output aural signal output from the transmitter.

14. A method for reducing unwanted aural carrier modulation caused by a video signal in a common amplification television transmitter which amplifies both an aural signal and a visual signal simultaneously, the method comprising the steps of:

mixing an aural carrier with an amplitude modulated video signal to generate a commonly amplified television transmission signal;

demodulating the commonly amplified television transmission signal to provide a demodulated aural signal;

performing a spectral analysis of the demodulated aural signal to determine the presence and frequency of unwanted aural signal noise resulting from unwanted aural carrier modulation;

generating a non-linear amplitude domain video signal and a non-linear phase domain video signal which respectively having amplitude and phase components that are directly opposite to unwanted amplitude and phase components added to the aural signal by the video signal;

amplitude and phase modulating the aural signal using the non-linear amplitude domain video signal and the non-linear phase domain video signal, respectively, to generate a modified aural signal; and adding the modified aural signal to the visual signal in the transmitter.

The claimed correction circuit, represented by figure 1 from the '904 patent, is reproduced below:

NOTE: OPINION CONTAINS TABLE OR OTHER DATA THAT IS NOT VIEWABLE

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In the illustrated correction circuit, a video signal 25 is simultaneously inputted to both an IF vision modulator 19 and to a video delay circuit 13. The video signal travels simultaneously through these two separate paths before it is recombined by an adder 21 just prior to amplification. In the first path, the video signal 25 is inputted to an IF vision modulator 19 which converts the baseband video signal into an IF visual signal and outputs this signal to an adder 21. In the second path, the same video signal 25 is simultaneously fed into a video delay circuit 13 which delays the video signal and outputs it, first to a complementary non-linear amplifier 15, and then to an amplitude and phase modulator 17 which together "predistort" the aural signal to eliminate the problem of the H sync spurs. The modified aural signal is then outputted from the amplitude and phase modulator 17 to the adder 21. The signal output from the IF vision modulator 26 and the signal output from the amplitude and phase modulator 28 are combined by the adder 21 and then output to the remainder of the circuit for further processing and amplification.

In 1992, Harris, Comark's primary competitor in the UHF transmitter industry, began developing its own common amplification transmitter. Faced with the same H sync spur problem as Comark, Harris turned to Dennis Culling, an engineer based in Cambridge, England to design a correction circuit. Culling testified that he initially developed the Harris aural carrier correction circuit sometime during the week of February 8, 1993. On May 14, 1993, as it continued to develop and refine its precorrection circuit, Harris asked its patent attorney, Robert Sundheim, for an opinion on whether Harris's proposed design would infringe Comark's '904 patent. While Harris initially provided Sundheim with some information, the district court found that Harris directed Sundheim to obtain additional information not from Culling, the primary design engineer of the Harris circuit, but from David Danielsons, an engineer based in Quincy, Illinois. On July 7, 1993, Sundheim delivered to Harris's in-house patent counsel a five-page opinion letter concluding that the Harris device did not infringe the '904 patent either literally or under the doctrine of equivalents. On May 23, 1995, the U.S. Patent and Trademark Office (PTO) issued U.S. Patent No. 5,418,578 (the '578 patent) assigned to Harris for Culling's correction circuit.

On April 11, 1995, Comark filed an action for patent infringement in the District Court for the Eastern District of Pennsylvania. In the complaint, Comark alleged that Harris infringed claims 1 and 14 of the '904 patent. Harris denied that it infringed the '904 patent and further asserted that the '904 patent was invalid. The trial took place before a jury between March 6, 1997 and April 17, 1997. The jury found that Harris had willfully infringed both claims 1 and 14 of the '904 patent under the doctrine of equivalents and rejected Harris's defense of invalidity. The jury awarded Comark $7.7 million in compensatory damages. In a Memorandum and Order dated July 17, 1997, pursuant to its authority under 35 U.S.C. §§ 284-285 (1994), the district court doubled the damages awarded by the jury to $15.4 million in light of the jury's finding of willfulness and also awarded attorney fees. The July 17, 1997 Memorandum and Order also denied both...