The opinion of the court was delivered by: PATEL
On November 28, 1995, plaintiff Level One Communications, Inc., brought this action against defendant Seeq Corporation, Inc., alleging infringement of U.S. Patent No. 5,249,183 ("the '183 patent") and U.S. Patent No. 5,267,269 ("the '269 patent"). Both patents pertain to the electronic circuitry used to transmit and receive information over different communications media and among different computers on a common network. Defendant timely answered, asserting numerous affirmative defenses, and counterclaimed seeking a declaratory judgment of patent invalidity and non-infringement. Now before the court are the parties' memoranda regarding claim construction of the disputed patent terms.
Having considered the parties' arguments and submissions, and for the reasons set forth below, the court enters the following memorandum and order.
Plaintiff Level One is the sole assignee of the '183 patent, which issued on September 28, 1993, and is entitled "Interfacing Unit for Local Area Networks." The '183 patent concerns circuitry which allows a computer in a "local area network" ("LAN") to communicate over two different kinds of media, either a twisted pair wire or a coaxial cable, by means of a "media attachment unit" ("MAU"). The MAU is connected to the computer through an attachment unit interface ("AUI"). The MAU connects to the AUI at its AUI port and to the twisted pair wire at its twisted pair port. Plaintiff claims that the novelty of the '183 patent lies in the ability of a single MAU to automatically select either media depending on whether the twisted pair link is active. Plaintiff. Mem. at 1-2. Plaintiff asserts that Seeq makes and sells products known as "AutoDUPLEX CMOS Ethernet Interface Adapters" which are covered by the '183 patent.
The parties dispute a number of terms in independent claims 6 and 12 of the '183 patent. Claim 6 states in its entirety:
A local area network (LAN), a media attachment unit for interfacing an attachment unit interface to a twisted pair link, the media attachment unit comprising: a) an AUI port having data out, data in, and collision presence circuit coupling said attachment unit interface to said media attachment unit; b) a twisted pair port having data out, data in, and collision presence circuits for coupling said twisted pair link to said media attachment unit; and c) auto-engage means, coupled to said twisted pair link and responsive to inactivity on said twisted pair link, for putting said AUI port data in and said AUI port collision presence circuits into high impedance condition, thereby disabling communication between said attachment unit interface and said twisted pair link, said auto-engage means further comprises means for monitoring said twisted pair link for a link integrity test pulse or a valid data pulse, and means for identifying inactivity on said twisted pair link when neither said link integrity test pulse or valid data pulse are present for a predetermined time.
A 10Base-T MAU comprising an AUI port in accordance with proposed standards of IEEE supplement (P802.31/D10) for LANs, and an auto-engage means, responsive to activity on a twisted pair link, for engaging said AUI port to an AUI wherein said auto-engage means further comprises means for monitoring said twisted pair link for a link integrity test pulse or a valid data, and means for identifying inactivity on said twisted pair link when neither said link integrity test pulse or valid data pulse are present for a predetermined time.
The prosecution history of the '183 patent includes an Office Action with a mailing date of September 8, 1992. Guy Decl., Ex. B. In response to the examiner's rejection of the proposed patent claims as unpatentable over the prior art, the patent was amended on January 11, 1993, and allowed on March 23, 1993. Pl. Opp'n, App. B & C.
Level One is also the sole assignee of the '269 patent, which issued on November 30, 1993. The '269 patent concerns the digital predistortion and prefiltering of data sent between computers in a common LAN. Predistortion is necessary in order to compensate for the natural distortion that occurs as signals are transmitted over a wire, making the received signals relatively free from distortion. According to plaintiff, the '269 patent is unique in that a single chip performs the predistortion and prefiltering and does so digitally. Pl. Mem. at 2.
The parties dispute terms contained in claims 1 and 8 of the '269 patent. Claim 1 reads:
A data communication system employing transmit equalization comprising: a) a sequencer for receiving data in a non-return to zero format and providing a mode select output for selecting one of a plurality of data patterns and a step select output for selecting one of a plurality of time segments in response thereto; b) memory for storing data representing a plurality of predetermined waveforms; c) a multiplexer having a first input coupled to step select output, a second input coupled to the mode select output, in input bus coupled to the memory and an output bus for providing data representing a select waveform from the memory in response to the step and mode select outputs; d) a latch having an input coupled to the output bus and an output for de-skewing the data representing the select waveform; e) a differential digital to analog converter having an input coupled to an output of the latch and providing a differential analog current output proportional to the select waveform; and f) driver means including low pass filter means having a differential input coupled to the current output for impressing an analog voltage onto a transmission line.
'269 Patent at 6:49-7:4. And Claim 8 reads:
In the first Office Action of the '269 Patent, dated September 18, 1992, the examiner rejected the claims because he found they lacked an adequate written description of the invention. Guy Decl., Ex. E. The application for the '269 patent was amended and the examiner's rejection addressed on December 21, 1992. Guy Decl., Ex. F. The patent was allowed on March 18, 1993. Pl. Opp'n, App. D.
Both patents at issue in this action incorporate by reference Standard 802.3 for LANs as set forth by the Institute of Electrical and Electronic Engineers ("IEEE"). Guy Decl., Exhs. G, H & I. In addition, the parties previously submitted briefs to this court on the issue of claim construction. Based on the fact that at that time the parties could not agree on which terms were actually in dispute, the court ordered them to meet and confer and if necessary to engage in mediation. The parties met with mediator Lynn Pasahow and the court is in receipt of his letter to counsel for both sides summarizing the agreements reached on a number of terms and the disagreements still outstanding. Pl. Mem., App. F.
Under Markman v. Westview Instruments, Inc., 52 F.3d 967, 979 (Fed. Cir. 1995), aff'd 517 U.S. 370, 116 S. Ct. 1384, 134 L. Ed. 2d 577 (1996), the court "has the power and obligation to construe as a matter of law the meaning of language used in the patent claim." The meaning of claims is ascertained from consideration of three sources: the claim language, the patent specification, and the prosecution history. Id.; see Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576 (Fed. Cir. 1996). In construing the meaning of claim language, the court should look first at the claims themselves, then use the specifications to aid in defining the terms used in the claims, and finally, turn to the prosecution history if necessary. Id. at 1582. Ordinarily this intrinsic evidence should be sufficient to resolve any ambiguities and determine the meaning of the disputed claims. Id. at 1583. Only when it is not may the court use extrinsic evidence and then only to aid the court in "coming to the proper understanding of the claims; it may not be used to vary or contradict the claim language." Id. at 1584. While courts may rely on experts and other extrinsic evidence to help it gain a basic understanding of the technology, expert testimony going to the proper construction of a disputed claim is to be eschewed and used only in the rarest circumstances. Id. at 1585. When reference to extrinsic evidence is necessary, the Federal Circuit in Vitronics showed a clear preference for dictionaries and prior art documents over expert opinion. Id.
A. Means-Plus-Function Claims
A means-plus-function claim is allowed by the Patent Act:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
35 U.S.C. § 112, P 6. The Federal Circuit has not explicitly resolved how its Markman holding affects interpretation of means-plus-function claims. An accused device literally infringes a claim written in means-plus-function form when the device "perform[s] the identical function required by the limitation and . . . incorporate[s] the structure disclosed in the specification, or its substantial structural equivalent, as the means for performing that function." Intellicall, Inc. v. Phonometrics, Inc., 952 F.2d 1384, 1388-89 (Fed. Cir. 1992); see also Texas Instruments, Inc. v. United States Int'l Trade Comm'n, 805 F.2d 1558, 1562 (Fed. Cir. 1986), reh'g denied, 846 F.2d 1369 (Fed. Cir. 1988). According to case law not overruled by Markman, courts must interpret the language of means-plus-function claims as a matter of law. In re Hayes Microcomputer Prods., Inc. Patent Litigation, 982 F.2d 1527, 1541 (Fed. Cir. 1992). However, although the determination of equivalents is usually a question for the jury, the trial court should grant summary judgment "in any case where no reasonable fact finder could find equivalence." Sage Products, Inc. v. Devon Industries, Inc., 126 F.3d 1420, 1997 WL 578762, *2 (Fed. Cir. 1997); see also Hilton Davis Chem. Co. v. Warner-Jenkinson Co., Inc., U.S. , 117 S. Ct. 1040, 1053-54, 137 L. Ed. 2d 146 (1997) ("Where the evidence is such that no reasonable jury could determine two elements to be equivalent, district courts are obliged to grant partial or complete summary judgment."); In re Donaldson Co., Inc., 16 F.3d 1189, 1193-95 (Fed. Cir. 1994).
With respect to burdens of proof on claim construction, this court has determined that since claim construction is a question of law reviewed de novo, it makes no sense to apply burdens of proof. Northern Telecom Ltd. v. Samsung Electronic Co., Ltd, 1996 U.S. Dist. LEXIS 21786, *29, 1996 WL 532122 at *9 n.11 (N.D.Cal. Sept. 16, 1996). "Claim construction is the first part of a two-part analysis in an action for infringement, the second part being the determination of whether the accused device or method infringes the claims at issue. The party claiming that its patent has been infringed ordinarily carries the burden of proof. Wilson Sporting Goods v. David Geoffrey & Assoc., 904 F.2d 677, 685 (Fed. Cir.), cert. denied, 498 U.S. 992, 112 L. Ed. 2d 547, 111 S. Ct. 537 (1990). However, only the second part is tried to a jury or finder of fact. The claim construction is determined as a matter of law, Markman, 116 S. Ct. at 1396, and matters of law generally are not subject to traditional burdens of proof." Id.
The parties dispute the meaning of six terms within Claim 6:1) "media attachment unit," 2) "attachment unit interface," 3) "AUI port," 4) "twisted pair port," 5) "auto-engage means," and 6) "high impedance condition." The terms at issue in Claim 12 are among those disputed in Claim 6 and the parties disagree about whether their meaning is the same in both claims.