## United States Court of Appeals for the Federal Circuit

05-1261, -1262, -1263, -1264, -1302, -1303, -1304 LG ELECTRONICS, INC., Plaintiff-Appellant,

v. BIZCOM ELECTRONICS, INC., COMPAL ELECTRONICS, INC., and SCEPTRE TECHNOLOGIES, INC., Defendants-Cross Appellants,

and EVEREX SYSTEMS, INC., Defendant-Appellee,

and FIRST INTERNATIONAL COMPUTER INC. and FIRST INTERNATIONAL COMP UTER OF AMERICA, INC., Defendants-Cross Appellants,

and Q-LITY COMPUTER, INC., QUANTA COMPUTER, INC., and QUANTA COMPUTER USA, INC., Defendants-Cross Appellants.

Richard G. Taranto , Farr & Taranto, of Washi ngton, DC, argued for plaintiffappellant. On the brief was Michael J. Schaengold , Patton Boggs LLP, of Washington, DC. William J. Anthony, Jr. , Orrick, Herrington & Sutcliffe LLP, of Menlo Park, California, argued for defendants-cr oss appellants Bizcom Electronics, Inc., et al. With him on the brief were Eric L. Wesenberg , Kaiwen Tseng , Matthew J. Hult and Rowena Y. Young

.2

Joseph L. Strabala , Law offices of Joseph L. Strabala, of San Francisco, California for defendant-appellee Everex Systems, Inc ., joined in the co-defendants’ briefs. Ronald S. Lemieux , Paul, Hastings, Janofsky & Walker LLP, of Palo Alto, California for defendants-cross appellants First International Computer, Inc., et al. Of counsel on the brief was James M. Smith , Squire, Sanders & Demp sey L.L.P., of Palo Alto, California. Terry D. Garnett , Paul, Hastings, Janofsky & Walker LLP, of Los Angeles, California for defendants-cross appellants Q-Lity Computer, In c., et al. With him on the brief were Vinent K. Yip , Maxwell A. Fox , Peter J. Wied , Sang N. Dang and Jay C. Chiu

. Of counsel was Jeffrey D. Mills , Fulbright & Jaworski L.L.P., of Austin, Texas.

Joel E. Lutzker , Schulte Roth & Zabel LLP, of New York, New York, for amicus curiae Minebea Co., Ltd. With him on the brief were David H. Kagan and Richard Chern

. Steven E. Feldman , Welsh & Katz, Ltd., of Chicago, Illinois, for amicus curiae Papst Licensing GmbH & Co. KG. Appealed from: United States District Cour t for the Northern District of California Judge Claudia Wilken

## United States Court of Appeals for the Federal Circuit

05-1261, -1262, -1263, -1264, -1302, -1303, -1304

LG ELECTRONICS, INC., Plaintiff-Appellant,

v. BIZCOM ELECTRONICS, INC., COMPAL ELECTRONICS, INC., and SCEPTRE TECHNOLOGIES, INC., Defendants-Cross Appellants,

and EVEREX SYSTEMS, INC., Defendant-Appellee,

and FIRST INTERNATIONAL COMPUTER INC. and FIRST INTERNATIONAL COMP UTER OF AMERICA, INC., Defendants-Cross Appellants,

and Q-LITY COMPUTER, INC., QUANTA COMPUTER, INC., and QUANTA COMPUTER USA, INC., Defendants-Cross Appellants.

__________ ________________ DECIDED: July 7, 2006

__________________________05-1261, -1262, -1263, -1264, -1302, -1303, -1304 2 Before MICHEL, Chief Judge , NEWMAN, and MAYER, Circuit Judges

. MAYER, Circuit Judge

. LG Electronics, Inc. (“LGE”) appeals from t he final judgment of the United States District Court for the Northern District of California, whic h granted summary judgment of noninfringement of U.S. Pa tent Nos. 4,918,645; 5, 077,733; 4,939,641; 5,379,379; and 5,892,509 in favor of Bizcom Electronics, In c.; Compal Electron ics, Inc.; Sceptre Technologies, Inc.; First International Comput er, Inc.; First International Computer of America, Inc.; Q-Lity Computer, Inc.; Quant a Computer, Inc.; Quanta Computer USA, Inc.; and Everex Systems, Inc. (collectively “defendants”). LG Elecs., Inc. v. Ausustek Computer, Inc. , Nos. C-01-1375, -1552, -1594, -2187 (N.D. Cal. Jan. 31, 2005); LG Elecs., Inc. v. Ausustek Computer, Inc. , Nos. C-01-1375, -1594, - 2187, -1552 (N.D. Cal. Nov. 30, 2004); LG Elecs., Inc. v. Ausustek Computer, Inc. , 248 F. Supp. 2d 912 (N.D. Cal. 2003); LG Elecs., Inc. v. Ausustek Computer, Inc. , Nos. C-01-326, -1375, -1594, - 2187, -1552 (N.D. Cal. Aug. 20, 2002) (“ Intel I ”). LGE also appeals and defendants cross appeal various claim constructi on rulings by the trial court. LG Elecs., Inc. v. Ausustek Computer, Inc. , Nos. C-01-00326, -01375, -01594, -02187, -01552 (N.D. Cal. Aug. 20, 2002) (“ Claim Construction Order ”). Defendants First In ternational Computer, Inc.; First International Computer of Amer ica, Inc.; Q-Lity Co mputer, Inc.; Quanta Computer, Inc.; and Quanta Co mputer USA, Inc. also cross appeal the denial of summary judgment based on their implied license defense. LG Elecs., Inc. , 248 F. Supp. 2d 912.05-1261, -1262, -1263, -1264, -1302, -1303, -1304 3 Background LGE is the owner of patents relating to personal computers, including U.S. Patents Nos. 4,918,645 (disclosing systems and methods that increase the bandwidth efficiency of a computer’s system bus); 5,077, 733 (claiming, in relevant part, a method

that controls the access of a device to a bus shared by multiple devices); 4,939,641 (claiming, in relevant part, a system for ensur ing that outdated data is not retrieved from memory); 5,379,379 (claiming a system and me thod for ensuring that outdated data is not retrieved from memory); and 5,892,509 (claiming networked computers capable of sharing certain video images ). LGE sued defendants allegi ng infringement of these patents. Defendants purchase microprocessors and chip sets from Intel or its authorized

distributors and install them in computers. Intel is authori zed to sell these products to defendants under an agreement with LGE. However, pursuant to this agreement, Intel notified defendants that, although it was licensed to sell the products to them, they were

not authorized under t hat agreement to combine the pr oducts with non-Intel products. LGE brought suit against def endants, asserting that the combination of microprocessors or chipsets with other computer component s infringes LGE’s patents covering those combinations. LGE did not a ssert patent rights in the microprocessors or chipsets

themselves. After construing the patent claims, the trial court granted summary judgment of noninfringement of each patent. It determined t hat there was no implied license to any defendant, but that, with the exc eption of the ’509 patent, LGE’s rights in any system

claims were exhausted. The court also f ound that LGE was contra ctually barred from05-1261, -1262, -1263, -1264, -1302, -1303, -1304 4 asserting infringement of t he ’509 patent against defendants. It found the ’645, ’733, and ’379 patents not infringed after applying its claim construction to the accused methods and devices. We have jurisd iction under 28 U.S.C. § 1295(a)(1).

Discussion “We review the trial court's grant of summary judgment without deference, reapplying the same standard as the trial court.” Lacavera v. Dudas , 441 F.3d 1380 (Fed. Cir. 2006) (citing Star Fruits S.N.C. v. United States , 393 F.3d 1277, 1281 (Fed. Cir. 2005)). Summary judgment is appropriate “if the pleadings, depositions, answers to interrogatories, and admissions on file, together with the affi davits, if any, show that there is no genuine issue as to any material fa ct and that the moving party is entitled to a judgment as a matter of law.” Fed. R. Civ . P. 56(c). We review claim construction de

novo

. Cybor Corp. v. FAS Techs., Inc. , 138 F.3d 1448, 1456 (Fed. Cir. 1998) (en banc).

I. Implied License 1 “In a suit for patent infringement, the burden of proving the establishment of an implied license falls upon the defendant.” Bandag, Inc. v. Al Bolser's Tire Stores, Inc. , 750 F.2d 903, 924 (Fed. Cir. 1984) (citing Bassick Mfg. Co. v. Adams Grease Gun Corp. , 54 F.2d 285, 286 (2d Cir. 1931)). To prevail, def endants were required to establish that the products have no noninf ringing uses and that “the circumstances of the sale . . . ‘plainly indicate that t he grant of a license s hould be inferred.’” Met-Coil

1 First International Computer, Inc.; Firs t International Computer of America, Inc.; Q-Lity Computer, Inc.; Quanta Co mputer, Inc.; and Quant a Computer USA, Inc. are the defendants challenging the trial court’s im plied license ruling.05-1261, -1262, -1263, -1264, -1302, -1303, -1304 5 Sys. Corp. v. Korners Unlimited, Inc. , 803 F.2d 684, 686 (Fed . Cir. 1986) (quoting Bandag, Inc. , 750 F.2d at 925). The trial court found, and we agree, that Intel’s sales of its licensed products to defendants do not warrant the inference of a license with respect to the asserted patents. Regardless of any noninfri nging uses, Intel expressly informed them that Intel’s license agreem ent with LGE did not extend to any of defendants’ products made by combining an In tel product with non-Intel products. In light of this express discla imer, no license can be implied.

II. Patent Exhaustion The patents asserted by LGE do not cover the products licensed to or sold by Intel; they cover those products when comb ined with additional com ponents. The trial court, nevertheless, found that the system claims in all patents except the ’509 patent were exhausted, but that the exhaustion doctrine did not apply to the method claims. We reverse the trial court’s holding with re spect to the system claims and affirm with respect to the method claims. It is axiomatic that the patent exhaustion doctrine, commonly referred to as the first sale doctrine, is tri ggered by an unconditional sale. See Mitchell v. Hawley , 83 U.S. 544, 547 (1873). “[A]n unconditional sale of a patented devic e exhausts the patentee's right to control the purchaser’s use of the dev ice thereafter. The theory behind this rule is that in such a transaction, the patentee has bargained for, and received, an amount equal to the full value of the goods. This exhaustion doctrine, how ever, does not apply to an expressly conditional sale or license. In such a transaction, it is more reasonable to infer that the parties negotiated a price that reflects only the value of the ‘use’ rights05-1261, -1262, -1263, -1264, -1302, -1303, -1304 6 conferred by the patentee.” B. Braun Med. Inc. v. Abbott Labs. , 124 F.3d 1419, 1426 (Fed. Cir. 1997) (discussing Mallinckrodt, Inc. v. Medipart, Inc. , 976 F.2d 700, 708 (Fed. Cir. 1992)) (emphasis added and citations omitted). There are two sales at issue here. First, pr ior to this litigati on, LGE granted Intel a license covering its entire por tfolio of patents on computer systems and components.

This transaction constitutes a sale for exhaustion purposes. See United States v. Masonite Corp. , 316 U.S. 265, 278 (1942). Second, with LGE’s aut horization, Intel sold its microprocessors and chipsets to each defendant. Notably, this sale involved a component of the asserted patented invention, not t he entire patented system. The trial court issued two orders on patent ex haustion. The first is unclear about

which sale the court relied upon in holding LG E’s system patent rights exhausted with respect to defendants, but we understand it to be LGE’s license to Intel. Intel I at 9-10. However, the second order, which reaffirmed the first, clearly relied on Intel’s sale of its microprocessors and chipsets to defendants as the exhausting sale. LG Elecs., Inc. , 248 F. Supp. 2d at 917. In finding the unconditional sale requirement satisfied, the court concluded that although “LGE is entitl ed to impose conditions on the sale of the essential components of its pat ented products does not mean t hat it actually did so here. To the contrary, defendants’ purchase of the microprocessors and chipsets from Intel was unconditional, in that defendants’ purchase of the microprocessors and chipsets from Intel was in no way conditi oned on their agreement not to combine the Intel microprocessors and chipsets with other non-Intel parts and t hen sell the resultant products.” Id. at 916-17. We disagree.05-1261, -1262, -1263, -1264, -1302, -1303, -1304 7 The LGE-Intel license expressly disclaims granting a license allowing computer system manufacturers to combine Intel’s licensed parts with other non-Intel components. Moreover, this conditional agreement required Intel to notify its customers of the limited scope of the licen se, which it did. Although In tel was free to sell its microprocessors and chipsets, those sales we re conditional, and Intel’s customers were expressly prohibited from infri nging LGE’s combi nation patents. Cf. N.Y. U.C.C. Law § 2-202 (allowing contracts to be supplemented by consistent additional terms unless the writing is intended to be complete and exclusive). The “exhaustion doctrine . . . does not apply to an expressly conditional sale or license,” B. Braun Med. Inc. , 124 F.3d at 1426, so LGE’s rights in asserting infringement of its system claims were not

exhausted. Conversely, the trial court declined to find LGE’s asserted method claims exhausted. Several defendants contest this ruling on cross-appeal, and we reject their challenge. Based on the above reasoning, even if the exhaustion doctrine were applicable to method claims, it would not apply here because there was no unconditional sale. However, the sale of a device does not exhaus t a patentee’s rights

in its method claims. Glass Equip. Dev., Inc. v. Besten, Inc. , 174 F.3d 1337, 1341 n.1 (Fed. Cir. 1999) (citing Bandag, Inc. , 750 F.2d 903, 924 (Fed. Cir. 1984)). The court

was correct.

III. ’509 Patent The ’509 patent discloses a system of networked computers capable of sharing video images. The trial court’ s exhaustion ruling did not extend to the ’509 patent;05-1261, -1262, -1263, -1264, -1302, -1303, -1304 8 instead it granted summary j udgment of noninfringement on the ground that LGE was contractually barred from asserting infrin gement of the ‘509 pa tent claims against

defendants. This conclusion was based on a non-assertion provision in a contract between LGE and Microsoft, which barred LGE from suing “[Microsoft], its suppliers, their subsidiaries, or their licensees.” 2 The court concluded that defendants were

included within this cla ss of parties. Because a genuine i ssue of material fact exists as

to whether defendants fall within t he protection of this contract provision, we reverse the trial court’s grant of summary ju dgment of noninfringement. In determining whether LGE is barred unde r the LGE-Microsoft agreement from suing defendants for infringement, the disposit ive issue is whether each defendant is a

Microsoft licensee. Defendants are third-party installers (“TPIs”) that assemble computers for original equipm ent manufacturers (“OEMs”). The OEMs have licenses with Microsoft, and it is undisp uted that defendants were authoriz ed to install Microsoft’s products on the systems they manufacture. It is unclear, however, whether defendants’

authorization was under “hav e made” rights of the OEMs ’ agreements with Microsoft, whereby the OEM would be authorized to use a third party for completing work on its

2 The relevant contract provision provides: {As partial consideration for the rights granted to [[LGE] under the License Ag reement(s), [LGE] agrees not to (A) sue, or (B) bri ng, prosecute, assist or participate in any judicial, administrative or other proceedings of any kind against [Microsoft], its Suppliers, their subsidiaries, or their licensees (including without limitation [original equipment manufacturer] customer s and end users) for infringement of [LGE’s] Patents . . . which occurs during the Immunity period . . . on account of the manufacture, use, sale, or distribution of . . . [the product’s licensed to LGE by Microsoft].}05-1261, -1262, -1263, -1264, -1302, -1303, -1304 9 behalf, or whether such authorization was as a sublicensee. If the work was authorized solely by an OEM’s have made rights, and if that OEM were not authorized to grant sublicenses under its agreem ent with Microsoft, then def endants may not be “licensees” protected by the LGE-Microso ft non-assertion provision. Cf. Cyrix Corp. v. Intel Corp. , 77 F.3d 1381, 1388 (Fed. Cir . 1996) (distinguishing “have made rights” from sublicenses). A genuine issue of material fact exists as to each defendant’s status. On remand, defendants must establish th at LGE is contractually barred from pursuing infringement cl aims against them. See McCoy v. Mitsuboshi Cutlery, Inc. , 67 F.3d 917, 920 (Fed. Cir. 1995). Although the par ties have relied on the LGE-Microsoft agreement in arguing whether or not defendants are Microsoft licensees, that agreement is not the proper focus. It is the agr eements between each OEM and each defendant, and those between Microsoft and the OEM hiring each defendant that

matter. The record indicates that FIC was both a TPI and an OEM. As an OEM, it had a license from Microsoft, and therefore falls s quarely within the scope of protected parties under the non-assertion provisi on. However, the contract provision only bars suit against Microsoft licensees for infringement “ on account of” the manufacture, use, sale, or distribution of Microsoft’s products. LGE does not dispute that there is no infringement absent the Microsoft software in the accused devices, since the software satisfies some, but not all, limitations of the ’509 patent claims. However, LGE argues that any infringement was not “on account of” the use of Mi crosoft products. The trial court rejected this argument, essentially readi ng the “on account of language” as a “but for” requirement.05-1261, -1262, -1263, -1264, -1302, -1303, -1304 10 The “on account of” language, however , is not susceptible of only one interpretation. According to the Supreme Court in construing this phrase in an unrelated statute, “the phrase ‘on account of’ does not unam biguously define itself.” O’Gilvie v. United States , 519 U.S. 79, 82 (1996) (construing 26 U.S.C. § 7405 (b)). Here, too, the degree of causation required by this contra ct term is unclear. Because proper construction requires factual considerations , we reverse the trial court’s grant of summary judgment. Scott Galvanizing, Inc. v. Nw. EnviroServices, Inc. , 844 P.2d 428, 433 (Wash. 1993); see also BNC Mortgage, Inc. v. Tax Pros, Inc. , 46 P.3d 812, 819-820 (Wash. Ct. App. 2002) (“If t he contract's written words have two or more reasonable meanings (i.e., are ‘ambiguous’) when read in context, a court may not grant summary judgment or direct a verdict; inst ead, it must put the case to a trier of fact.”) (citations omitted). The parties also dispute the trial court’s construction of several claim terms in the ’509 patent. Claim 35, from which asserted claims 45 and 51 depend, contains the limitation of “a control unit for controlling the communication unit, wherein the control unit comprises a [central processing unit (“CPU”)] and a partitioned memory system.” LGE contends that the trial court erroneously construed the term “control unit” as a means-plus-function limitation. “‘[A] claim term that does not use ‘means’ will trigger the rebu ttable presumption that § 112 ¶ 6 does not apply.’” Lighting World, Inc. v. Birchwood Lighting, Inc. , 382 F.3d 1354, 1358 (Fed. Cir. 2004) (quoting CCS Fitness, Inc. v. Brunswick Corp. , 288 F.3d 1359, 1369 (Fed. Cir. 2002)). This presumption can be rebutted “by showing that the claim element recite[s] a function without reciting sufficient structure for performing05-1261, -1262, -1263, -1264, -1302, -1303, -1304 11 that function.” Watts v. XL Sys. , 232 F.3d 877, 880 (Fed. Cir. 2000) (citing Rodime PLC v. Seagate Tech., Inc. , 174 F.3d 1294, 1302 (Fed. Cir. 1999)). However, the presumption “is a strong one that is not readily overcome.” Lighting World, Inc. , 382

F.3d at 1358. Here, the claim limitation at issue does not use the term “means,” and the presumption against means-plus-function treatment is not overcome. The claim itself provides sufficient structure, namely “a CPU and a partitioned memory system,” for performing the stated function, “cont rolling the communication unit.” See id. at 1359-60. Thus, the proper construction of “control unit” is “a combination comprising a CPU and a partitioned memory system capable of c ontrolling the communication unit.”

Defendants contend on cross appeal that the trial cour t also misconstrued claim 35 by not requiring multiple displays. In par ticular, they contend that the preamble term “image processing system” requires multiple displa ys in light of the prosecution history. However, the claim language does not include this limitation, and the trial court properly

refused to read it into the claim. Moreov er, the body of the claim provides for “a display.” KCJ Corp. v. Kinetic Concepts, Inc. , 223 F.3d 1351, 1356 (Fed. Cir. 2000) (“This court has repeatedly emphasized that an i ndefinite article ‘a’ or ‘an’ in patent parlance carries the meaning of ‘one or more’ in open-ended claims containing the transitional phrase ‘comprising.’ ”) (citations omitted). Claim differentiation also supports the trial court’s construction because depe ndent claim 38 adds the limitation of the “image processing system further compris[ing] at least first and second displays coupled to the CPU of the im age processing system.” See Phillips v. AWH Corp., 415 F.3d 1303, 1314 (Fed. Cir. 2005) (“Differences among claims can also be a useful guide in05-1261, -1262, -1263, -1264, -1302, -1303, -1304 12 understanding the meaning of part icular claim terms.” (citing Laitram Corp. v. Rexnord,

Inc. , 939 F.2d 1533, 1538 (Fed. Cir. 1991))). The prosecution history relied upon by defendants does not compel a different construction. The patentee made arguments dur ing prosecution to di stinguish claims in the parent application to the ’509 patent, which expressly r equired multiple displays, over the prior art. These arguments, however, do not compel reading a multiple display limitation into the ’509 patent, which does not expressly require multiple displays. See Elkay Mfg. Co. v. Ebco Mfg. Co. , 192 F.3d 973, 980 (Fed. Cir. 1999) (“When multiple patents derive from the same in itial application, the pros ecution history regarding a claim limitation in any patent that has issu ed applies with equal fo rce to subsequently issued patents that contain the same claim limitation .” (emphasis added)).

IV. ’645 patent The ’645 patent discloses a digital comp uter system that has devices called agents that are interconnected by a syst em bus. The claimed system and corresponding method require one agent, the requesting agent, to request access to a memory stored on another agent, called t he replying agent. The requested data is organized as a matrix of memory cells, hav ing column and row coordinates. The “memory controller” of the replying agent pr ocesses the request from the requesting agent by asserting a plur ality of memory address control si gnals, including at least one row address strobe (“RAS”) signal and one colu mn address strobe (“CAS”) signal. This “page mode memory access” operates by the a ssertion of an entire row of data followed by the assertion and deassertio n of multiple column addresses. By the RAS signal05-1261, -1262, -1263, -1264, -1302, -1303, -1304 13 accessing an entire row followed by the asse rtion and deassertion of particular column addresses, this page mode memory access differs from the conventional memory access, which separately accessed each memory cell by asserting its individual row

address and column address. In the claimed invention, after the data is accessed, it is then transferred to the requesting agent over the system bus. LGE alleged infringement of system claims 1-4 and 6 and method claims 12-15 and 17. The trial court granted summary j udgment of noninfringement of all asserted claims, concluding that the RAS/CAS signals in defendants’ devices did not travel over the system bus. However, the ’645 patent cl aims do not contain a limitation requiring that the strobe signals travel over the system bus. Moreov er, the specific ation does not suggest that the strobe signals must travel ov er the system bus. To the contrary, Figure

5 shows an embodiment of th e invention in which the strobe signals travel only internally within the replying agent, not across the system bus. In an attempt to impose this limitati on on the claims, defendants rely on the prosecution history. While the prosecution history is re levant to claim construction, “it often lacks the clarity of the s pecification and thus is less us eful for claim construction purposes.” Phillips , 415 F.3d at 1317 (cit ations omitted). Here, defendants point to statements in the pros ecution history that the prior art does not teach “a page mode type of access over a system bus from a reques ting agent to a replyi ng agent.” While we agree that this and other st atements in the prosecution hi story lack ideal clarity, we do not find that they rise to the level of disclaiming or limiting the scope of the express claim language. Therefor e, the trial court erred in cons truing the ’645 claims to require the RAS and CAS signals to travel over the system bus. In addition, there is a genuine05-1261, -1262, -1263, -1264, -1302, -1303, -1304 14 issue of material fact as to whether the accused devices and methods utilize strobe signals. LGE’s expert submitted an affidavit that the accused devices employ strobe signals, which precludes summary judgment. In the alternative, defendant s contend that LGE failed to present evidence of an “end of access signal.” This signal, which is required by the claims, is generated by the requesting agent and received by a detecting means coupled to the memory address control signal asserting means. When the det ection means receives this end of access signal, the operation is halt ed. Defendants contend that LG E failed to establish the existence of a genuine issue of material fact as to whether the accused devices contain this limitation. However, t he trial court did not consider this argument, and we will not

address this factual issue in the first instance. LGE also argues that the trial court’s construction of the “requesting agent” claim

limitation was in error. The court construed this term as “a device coupled to the system bus that requests access to a memory located on a replying agent.” Claim Construction Order at 6-9. LGE contends that an industry standard, which was incorporated into the specification by reference, pr ovides the proper claim constr uction of this term. ’645 patent col. 3 ll. 51-56. 3 The incorporated standard ex plicitly defines the term

3 The specification provides: Although the method and apparatus of the invention will be described her ein in the context of a Multibus II environment, it should be appreciated that the invention may be practiced in many digital computer systems having a bus for transferring data between at least two agents interconnected upon the bus. The operating characteristics of the Multibus II are described in a doc ument entitled “High05-1261, -1262, -1263, -1264, -1302, -1303, -1304 15 “requesting agent” as “an agent t hat has entered into the ar bitration function for bus access.” Defendants contend, however, that the patentee did not act as its own lexicographer by incor porating this industry standard by re ference. The trial court did not accept LGE’s proposed cons truction, concluding that it was a preferred embodiment

and did not limit the claimed invention. T he difference in the two constructions is temporal: LGE’s proposed construction def ines an agent as a requesting agent only when it is engaged in arbitration for bus acce ss, whereas the trial court’s construction defines a requesting agent regardless of whether it is actively engaged in arbitration. We have recognized that t he “[i]nterpretati on of descriptive statements in a patent's written description is a di fficult task, as an inherent tension exists as to whether a statement is a clear lexicographic defi nition or a description of a preferred

embodiment.” E-Pass Techs., Inc. v. 3COM Corp. , 343 F.3d 1364, 1369 (Fed. Cir. 2003). “Thus in determining whether a statement by a patentee was intended to be lexicographic, it is important to determine whether the stat ement was designed to define the claim term or to describe a preferred embodiment.” Id. We agree with the trial court and defendants that the patentee di d not act as its own lexic ographer here. Instead, the industry standard was incorporated as a pr eferred embodiment. The specification makes this clear by explaining that “[a]lthough the method and apparatus of the

invention will be described herein in the contex t of a Multibus II environment, it should

Performance 32-Bit Bus St andard P1296” which was produced by the IEEE microprocessor standards committee P1296 working group, Jun. 20, 1986, draft 2.0, the disclosure of whic h is incorporated herein in its entirety. ’645 patent col. 3 ll. 45-56.05-1261, -1262, -1263, -1264, -1302, -1303, -1304 16 be appreciated that the invent ion may be practiced in many digital computer systems having a bus for transferring data between at least two agents interconnected upon the bus.” ’645 patent co l. 3 ll. 45-49. Chimie v. PPG Industries, Inc. , 402 F.3d 1371 (Fed. Cir. 2005), does not compel

a different result. In Chimie , we were confronted with the claim terms “dust-free and non-dusting.” After concluding that thes e terms were relative and could only be understood by comparison with the prior ar t, we concluded that only one standard was disclosed in the specification for making such a comparison. We limited these claim

terms to the disclosed standard. Here, however, there is no re lative term that cannot be

understood without reference to an industry standard. But, this does not end our inqu iry. The proper claim construction is “the ordinary and customary meaning . . . that the term woul d have to a person of ordinary skill in the art in question at the time of the invention, i.e ., as of the effective filing date of the patent application.” Phillips , 415 F.3d at 1313 (citations omitted) . “When prior art that sheds light on the meaning of a term is cited by th e patentee, it can have particular value as a guide to the proper construction of the te rm, because it may indicate not only the meaning of the term to persons skilled in the art, but also that the patentee intended to adopt that meaning.” Arthur A. Collins, Inc. v. N. Telecom Ltd. , 216 F.3d 1042, 1045 (Fed. Cir. 2000). Although we have concluded t hat the patentee did not expressly adopt the definition of “requesting a gent” in the incorporated indu stry standard, that standard remains relevant in determining the meaning of the claim term to one of ordinary skill in the art at the time the patent application was filed, and it is treated as intrinsic evidence for claim construction purposes, see V-Formation, Inc. v. Benetton Group SpA , 40105-1261, -1262, -1263, -1264, -1302, -1303, -1304 17 F.3d 1307, 1311 (Fed. Cir. 2005) (“This court has es tablished that ‘prior art cited in a patent or cited in the prosecution history of the patent cons titutes intrinsic evidence.’”) (citations omitted). Here, the trial court erred by failing to give proper weight to the incorporated industry standard; it failed to consider the standard as intrin sic evidence of the meaning to one of ordinary skill in the art as of the filing date. A fter considering the standard, in addition to the patent claims and specificat ion, we conclude that LGE’s proffered

definition based on the standar d is correct. Thus, we construe “requesting agent” as “an agent that has entered into the arbitr ation function for bus access.” This construction is entirely consist ent with the specification, which provides that “at one time in the operation of the system . . . the reque sting agent 12 may be a replying agent, and that the replying agent 16 may at that time be a requesting age nt.” ’645 patent col.4 ll. 8-11. This language makes clea r that the classification of an agent depends upon the function the agent is performing at any gi ven time, i.e., whet her it is engaged in arbitration at a given moment.

V. ’733 patent The ’733 patent discloses a rotating prio rity system that provides multiple computer devices alternating access to a sy stem bus, which is t he pathway over which the various components of a computer system transmit dat a. This system addresses the problem of “hogging,” in which one component of a computer system monopolizes05-1261, -1262, -1263, -1264, -1302, -1303, -1304 18 access to the system bus. The asserted clai ms of the ’733 patent, method claims 15- 19, 4 establish a rotating priority system that limits each device’s access to the bus. In particular, claim 15 sets forth two steps of the method as “counting a number of accesses by the device to the bus” and then “i n response to a predetermined number of accesses to the bus, giving anot her [device] the highest priority.” The trial court granted summary judgment of noninfringement of the ’733 patent, holding that the claim limitation of “counting a number of accesses by the device to the bus” was not practiced

in the accused method.

The court construed the claim limitati on “counting a number of accesses” as “counting the number of times a dev ice gains use of the bus.” Claim Construction Order at 38-41. The parties do not directly challenge this constr uction, but LGE argues that a genuine issue of material fact exists as to whether the accused method performed this step. LGE argues that the master latency timer (“ML T”) in defendants’ accused devices performs this step. MLTs count clock si gnals when an anchor n ode has possession of

4 Claim 15, the only independent claim at issue, provides: A method for determining priority of access to a bus among a set of devices coupled to the bus, each device being represented for priority purposes by a node in a group of nodes and each node having a priority relative to a single node currently having the highes t priority, the method comprising the steps of: receiving an access request in a node from a represented device; determining whether any nod e with a higher priority has received an access request; if no such node has received an access request, permitting the device to access the bus; counting a number of accesses by the device to the bus; and in response to predetermined number of accesses to the bus, giving another node the highest priority.05-1261, -1262, -1263, -1264, -1302, -1303, -1304 19 the bus. Defendants contend t hat although an MLT limits the time duration of bus access by a device, it does not count the number of accesses by the device. Defendants also contend that, in some inst ances, the MLTs continue counting when clock signals pass even if no access to the bus is taking place, such as during WAIT periods when no data is being placed on the bus. LGE responds that the bus is accessed even during WAIT periods, regardless of whether any data is placed on the bus, because the device has access to the bus. LGE points out that the purpose of the invention is to eliminat e “hogging” the bus, and that the bus is “being hogged” even during WAIT per iods. Further, LGE argues that, under the trial court’s construction, a device still has “use of the bus” during a wait period. LGE points to the discussion in the ’733 patent relating to Figur e 8. ’733 patent col. 21. In this preferred embodiment, the descrip tion includes a programmable node grant counter NGCNT 720. The description explains that when certain conditions are met, an enable count input is assert ed and during a bus access cycle a transition of a clock signal causes NGCNT 720(1) to increment by one count. Therefore, when certain criteria are met, a clock signal can create an access count. There is a genuine issue of material fa ct as to whether the accused devices

count the number of accesses. See Ranbaxy Pharms., Inc. v. Apotex, Inc. , 350 F.3d 1235, 1240 (Fed. Cir. 2003) (“Infringement, bot h literal and under the doctrine of equivalents, is a question of fact.” (citing Insituform Techs., Inc. v. Cat Contracting, Inc. , 161 F.3d 688, 692 (Fed. Cir. 1998))). The central issue is whether the bus is accessed on each clock signal so that the clock signals, in effect, count the number of accesses to the bus. The trial court agr eed that LGE’s argument is consistent with its claim05-1261, -1262, -1263, -1264, -1302, -1303, -1304 20 construction, but found that it failed to present evidence supporting its position. To the contrary LGE presented sufficient expert te stimony on this issue to avoid summary judgment. LGE’s expert testif ied that some type of signal is asserted with each clock signal, and, if proven, this would in effect make the MLTs count accesses. The summary judgment is vacated.

VI. ’641 patent The ’641 patent discloses a system for en suring that the most current data is retrieved from the main memory. Because individual devices can update data in their own local cache memory without immediatel y writing the new data back to the main memory, data in the main memory can be “sta le.” Therefore, the system claimed in the ’641 patent monitors the data being transferred over the bus, and if data stored in the cache matches the address of the data being transferred, a hold signal is asserted. Then, the data being trans ferred is compared with the data on the cache. If there is a difference, the data stored on the cache, which is the most recent data, is also

transferred. The trial court concluded the ’641 patent claims asserted were not infringed based on its patent exhaustion holding, which we revers e above. However, LGE

contends that the trial court al so improperly construed claims 1, 5, and 14. In particular, LGE disputes the trial court’s construction of “cache memory means” (in claims 1 and 5) and “cache memory” (in claim 14), which were construed as “one of at least two high speed memories located close to the CPU of a computer to give the CPU faster access to blocks of data than could be taken directly from the larger, slow er main memory and05-1261, -1262, -1263, -1264, -1302, -1303, -1304 21 never using valid/invalid bits.” Claim Construction Order at 18-22. LGE contends that the trial court improperly read claims 1 and 14 as requiring at least two caches. It also contends that the trial court improperly read in the limitati on that neither cache uses valid/invalid bits. We agree with LGE that the tr ial court erred in reading the limitation of at least two high speed memories into claims 1 a nd 14. Unlike claim 5, which expressly requires at least two cache memory means, claims 1 and 14 have no such express

limitation. Cf. Phillips , 415 F.3d at 1314 (“Differences among claims can also be a useful guide in understanding the meaning of particular claim terms.” (citing Laitram Corp. v. Rexnord, Inc. , 939 F.2d 1533, 1538 (Fed. Cir. 1991))). To the contrary, claims 1 and 14 only require one or more CPUs and a cache memory coupled between the CPU and the bus. Because the claims expressly cover one central processing unit, they logically also cover systems with onl y one cache coupled between that single central processing unit and the bus. Def endants rely on the fact that the written description describes a system with multiple caches. Howe ver, as we explain in more detail below, the pat ent application initially descr ibed two inventions, and these

statements relate to the ot her invention that is not claimed in the ’641 patent. We also agree with LGE that the trial court im properly read the limi tation of never using valid/invalid bits into the claims. The patent’s background section suggests that valid/invalid bits were used to manage data in systems with more than one cache. In particular, it explains that the purpose of the invalid bit is to redirect a processor attempting to access an address in its cache to another cache with a more updated memory associated with that address. ’641 patent col. 1 ll. 44-52. The claims at issue05-1261, -1262, -1263, -1264, -1302, -1303, -1304 22 do not themselves expressly include or exclude the use of valid/invalid bits. Defendants, however, contend that the trial court’s constr uction is supported by the specification and prosecution hist ory. The specification states that “a further object of this invention [is] to provide a cache memo ry system wherein the use of valid/invalid data indicators are avoided.” ’641 patent col. 1 ll. 65-67. It further states that “[i]t should be kept in mind during the following description, that t he invention maintains data integrity by assuring that cache data is alwa ys the most up-to-date in the system. Thus,

there never is a ‘valid’ or ‘invalid’ indica tion with respect to any cache data as it is always assured that if data is pr ovided by a cache, that it in variably is valid (i.e. most up-to-date).” Id. col. 3 ll. 27-33. Defendants are correct that reviewing the specification in construing claims is appropriate, Phillips , 415 F.3d at 1315-17, but such review need not be done in the abstract. Here, as noted above, the original patent application disclosed two inventions. As the examiner observed, one invention wa s “drawn to a cache system for updating each copy of the data stored in a plurality of caches when t he data is modified,” and the other was drawn to “a cache system for send ing the most current data to a requestor by monitoring the address of a data on a data bus fo r detecting whether the [data] is stored and modified in the cache.” The patent examiner concluded that these two inventions were distinct and required the applicant to el ect one invention. The applicant ultimately limited the original applicati on to the latter group of claims , which issued as the ’641 patent, and the other claim group was separated into a di fferent application, which ultimately issued as U.S. Patent No. 5,097,409.05-1261, -1262, -1263, -1264, -1302, -1303, -1304 23Here, the discussion of valid/invalid bits in the specification was relevant to multicache systems, because the patent’s background provides that “[s] o long as a write

back cache is utilized with on ly one processor, data managemen t is straight forward. However, when more than one central processor uses the same main memory, data management problems multiply.” ’641 patent col. 1 ll. 39-43. The pat ent explains that the data management problems in multiple CPU systems are a result, at least in part, of their containing more than one cache memo ry. Managing data in multiple cache systems was the subject of the invention not elected during prosecut ion and, therefore, the statements in the specification referring to valid/invalid bits are not relevant to the invention ultimately claimed in the ’641 patent. Cf. Pitney Bowes, Inc. v. HewlettPackard Co. , 182 F.3d 1298, 1311 (Fed. Cir. 1999) (observing that a written description describing multiple inventions may not be relevant “in toto” to each of those inventions). Indeed, the unelected claims expressly contai ned the limitation that the “cache memory means hav[e] no provisions for indicating the in validity of said data units,” whereas the

elected claims contained no such limitation. For the same reasons, we do not find t hat the patentee disavowed the use of valid/invalid bits under the doctrine of specif ication disclaimer. “[T]he specification may reveal an intentional disclaimer, or disavowa l, of claim scope by an inventor. In that instance, . . . the inventor has dictated the correct claim scope, and the inventor’s intention, as expressed in the specification, is r egarded as dispositive.” Phillips , at 1316; see also SciMed Life Sys. v. Ad vanced Cardiovascular Sys. , 242 F.3d 1337, 1341 (Fed. Cir. 2001). However, because the stat ements relied upon by defendants relate to05-1261, -1262, -1263, -1264, -1302, -1303, -1304 24 the invention not elected during prosecution, there is no clear disavowa l with respect to the invention actually cl aimed in the ’641 patent.

VII. ’379 patent

Like the ’641 patent, the ’379 patent claims a system and method for ensuring that the most current data, as opposed to “stale” data, is retrieved from memory. The claimed invention relates to how a memory controller coordinates requests to read data from the memory and requests to write data to the memory . Generally, when a read request is asserted that corresponds to a bu ffered write request, the write request must go first to ensure that what is read from memo ry is the most current data. The invention disclosed in the ’379 patent does this by co mparing the address of each read request to the buffered write requests, noting any matches , halting read execution when there is a match, and executing the buffered write requests. LGE contends that the tria l court erred in construing system claims 1 and 23 as requiring all write requests to be executed after a match is detected, as opposed to executing any number of wr ite requests until the write request corresponding to the matching read request is executed. We agree. The claim language does not require all write requests to be executed after a match is detected. Moreover, claim 2, which depends from claim 1, expressly requires the execution of all write requests, as does independent method claim 7. See Phillips , 415 F.3d at 1314 (recognizing the utility of claim differentiation). In additi on, the claim limitation at i ssue is written in means-plus function-claim language (“means for . . . c ausing an execution of buffered write requests”). Because the recited function is clear on its face, it was improper to05-1261, -1262, -1263, -1264, -1302, -1303, -1304 25 incorporate the additional func tional limitation of executing “all” buffered write requests. Smiths Indus. Med. Sys., Inc. v. Vital Signs, Inc. , 183 F.3d 1347, 1357 (Fed. Cir. 1999);

see also Wenger Mfg., Inc. v. Coating Mach. Sys., Inc. , 239 F.3d 1225, 1233 (Fed. Cir. 2001) (“[A] court may not import functional limitations that are not reci ted in the claim . . . .”). LGE also disputes the trial court’s grant of summary judgment of noninfringment

of method claim 7. 5 This claim explicitly requires the step of buffering “each” read

5 Claim 7 provides: In an information processing system having a system bus for coupling together a plurality of bus connections, one of the bus connections being a memory control unit coupled to one or more memory units, the memory control unit being responsive to address and data signal lines of the system bus for writing information units to and for reading information units from the memory units, a method of reading and writing the information units comprising the steps of: buffering write requests, including write addresses, as they are received from the system bus; buffering read requests, including read addresses, as they are received from the system bus; comparing when received each read address against buffered write addresses, if any, to determine if a received read address has an address value within a predetermined range of address values of a buffered write address; if a received address is determined not to be within the predetermined range of ad dresses of any buffered write addresses then: first executing in sequence all buffered read requests; and then executing in sequence all buffered write requests; else if a received address is determined to have an address value within the predetermined range of address values of any bu ffered write address: first executing in sequenc e all buffered read requests up to but not including the received read request05-1261, -1262, -1263, -1264, -1302, -1303, -1304 26 request and then comparing that read request to the buffered write addresses. If the read request matches a write request, then the claim provi des for the following steps: executing all buffered read requests up to the matching request; then executing “all buffered write requests;” and then executing the matching read request. If, however, the comparison of the read reque st does not yield a match to a buffered write request, then all read requests are ex ecuted. Defendants contend, and LGE does not appear to dispute, that the accused dev ices do not operate in this manner. Instead, they contend that when a buffered read reque st matches a buffered write request, their devices do not execute “all” write reques ts before executing the matc hing read request, but instead only execute the write requests up to the one matching the read request, and then execute the matching read request. The trial court concluded, and we agree, th at there was no liter al infringement of this claim. The claimed method requires handling each read address in one of two ways depending on whether the read request matches a write request. The second way, which applies when the pending read reques t matches a pending write request, is to execute all write requests before exec uting the read request. LGE contends that when the matching write request happens to be the last in the buffer, all write requests

are in fact executed before the matching read request. Alt hough LGE correctly asserts that any practice of the claimed method would be infringement, Bell Commc’ns Research, Inc. v. Vitalink Commc’ns Corp. , 55 F.3d 615, 622 (Fed. Cir. 1995), the claim

which was determined to be within the predetermined range; then executing all buffered write requests; and then executing the buffered read request which was determined to be within the predetermined range.05-1261, -1262, -1263, -1264, -1302, -1303, -1304 27 must be considered in its entirety. Here, the claim requires each read request to be compared with the buffered writ e requests, and then one of two alternatives be followed.

Because the claim was drafted with this limitation, the fact that the accused device occasionally operates in such a manner does not amount to literal infringement of claim 7. For infringement to be found, the claim r equires the accused device to operate in this manner in response to “each” read request. The trial court also found, as a matter of law, that there was no infringement under the doctrine of equivalent s. In doing so, it reje cted LGE’s argument that performing all of the wr ite requests up to (and includi ng) the one matching the read request is an insubstantial difference from the claim limitation of performing all write requests before executing the incoming read request. The trial court reasoned that LGE’s equivalence theory would vitiate the claim limitation of performing “all” write requests before an incoming read request matching a write request. The doctrine of equivalents operates under the “all limit ations rule,” whereby “equivalence [is] assessed on a limitation-by -limitation basis, as opposed to from the perspective of the inv ention as a whole.” Freedman Seating Co. v. Am. Seating Co. , 420 F.3d 1350, 1358 (Fed. Cir. 2005) (citing Warner-Jenkinson Co. v. Hilton Davis Chem. Co. , 520 U.S. 17, 29 (1997)). This doctrine, by its ve ry nature, extends beyond the patent’s literal claim scope, because other wise a finding of no lit eral infringement

would be a foreordained conclusion of no infringement at all. Ethicon Endo-Surgery v. U.S. Surgical Corp. , 149 F.3d 1309, 1317 (Fed. Cir. 1998). At the same time, however, “[i]f our case law on the doctri ne of equivalents makes anything clear, it is that all claim05-1261, -1262, -1263, -1264, -1302, -1303, -1304 28 limitations are not entitled to an equal scope of equivalents.” Moore U.S.A., Inc. v. Standard Register Co. , 229 F.3d 1091, 1106 (Fed. Cir. 2000). “There is no set formula for determining whether a finding of equivalence would vitiate a claim limitation, and thereby violate t he all limitations rule. Rather, courts must consider the totality of the circumstances of each case and determine whether the alleged equivalent can be fairly characterized as an ins ubstantial change from the claimed subject matter without rendering the pertinent limitation meaningless.” Freedman Seating Co. , 420 F.3d at 1359 (cit ations omitted). LGE contends that performing some of the write requests is a permissible equivalent to performing all write requests, and that while perfo rming no write requests may vitiate the claim language, performing some does not. As discussed above, there is inevitably a range of equivalents for performing al l write requests, even if that range is narrow. See Ethicon Endo-Surgery , 149 F.3d at 1317. If substantially a ll or nearly all write requests are performed by the accused devices befor e each matching read request, then the doctrine of equivalents would be fully applicable without vi tiating the claim language. Although such scope would be outs ide of the claim’s literal scope, which is true in any doctrine of equivalents analysis, it would no t be inconsistent with the language of the claim. Therefore, a genuine is sue of material fact exists as to whether the accused device can function within the narrow range of equivalents that we have described above, and we vacate the tria l court’s grant of summary judgment of noninfringement on this ground.05-1261, -1262, -1263, -1264, -1302, -1303, -1304 29 Conclusion Accordingly, the judgment of the United States Distric t Court for the Northern District of California is affi rmed in-part, reversed in-part, and vacated in-part. The case is remanded for further proceedings in accordance with this opinion. COSTS LGE shall have its costs.

AFFIRMED-IN-PART, REVERSED-IN-PAR T, VACATED-IN-PART, AND REMANDED