Opinion · Court of Appeals for the Federal Circuit

Cybor Corporation v. Fas Technologies, Inc., and Fastar Ltd., Defendants-Cross

138 F.3d 1448

Type: Opinion
Court: Court of Appeals for the Federal Circuit
Jurisdiction: Federal
Date: 1998-03-25
Topic: general

noting that in Mark-man "the Supreme Court endorsed this court's role in providing national uniformity to the construction of a patent claim” | stating that a patent’s prosecution history “is relevant to the construction of a claim written in means-plus-function form” | explaining that “the properly construed claims ... [are] compared to the allegedly infringing device” | explaining that "the properly construed claims ... [are] compared to the allegedly infringing device" | explaining that an infringement analysis is a two-step process by which courts first determine the scope and meaning of patent claims and then compare those claims to the allegedly infringing product | declining to decide a motion for reconsideration under Rule 60 because the order was not final | "The relevant inquiry is whether a competitor would reasonably believe that the applicant had surrendered the relevant subject matter." | ―Finally, nothing in the record supports FAS‘s arguments that Cybor litigated in an inappropriate fashion; the district court actually found the contrary to be true.‖ | ―[T]here is no merit to the argument that a finding of willfulness but a denial of enhanced damages is necessarily an abuse of discretion.‖ | "The second step of the infringement analysis requires a factual comparison of the claimed invention to the accused device, which is done by the fact finder." | Rader, J., dissenting from the pronouncements on claim interpreta- tion in the en banc opinion | “The relevant inquiry is whether a competitor would reasonably believe that the applicant had surrendered the relevant subject matter.” | the comparison of the construed claims to the accused device is a question of fact | Rader, J., dissenting from the pronouncements on claim interpretation in the en banc opinion, concurring in the judgment, and joining part IV of the en banc opinion | “[W]e therefore reaffirm that, as a purely legal question, we review claim construction de novo on appeal including any allegedly fact-based questions relating to claim construction.’’ | “Prosecution history estoppel is a legal question subject to de novo review on appeal.” | Rader, J., dissenting from the pronouncements on claim interpre- tation in the en banc opinion, concurring in the judgment, and joining part IV of the en banc opinion | Rader, J., dissenting from the pronouncements on claim interpretation in the en banc opinion | "A district court abuses its discretion when its decision is based on clearly erroneous findings of fact, is based on erroneous interpretations of the law, or is clearly unreasonable, arbitrary or fanciful.'' | "A district court abuses its discretion when its decision is based on clearly erroneous findings of fact, is based on erroneous interpretations of the law, or is clearly unreasonable, arbitrary or fanciful." | “Prosecution history is relevant to the construction of a claim written in means-plus-function form.” | “Ultimately, a court must construe the claim language according to the standard of what those words would have meant to one skilled in the art as of the application date.” (emphasis added) | "Under § 112, P 6, an accused device with structure not identical to the structure described in the patent will literally infringe the patent if the device performs the identical function required by the claim with a structure equivalent to that described in the patent.” | defining an abuse of discretion

Citator

Cited by: 782 opinions

CYBOR CORPORATION v. FAS TECHNOLOGIES,138 F.3d 1448(Fed. Cir. 1998)

CYBOR CORPORATION, Plaintiff-Appellant, v. FAS TECHNOLOGIES, INC., and

FASTAR LTD., Defendants-Cross Appellants.

Nos. 96-1286, 96-1287.

United States Court of Appeals, Federal Circuit.

March 25, 1998.

Appealed from: U.S. District Court for the Northern District of California.Page 1449

[EDITORS' NOTE: THIS PAGE CONTAINS HEADNOTES. HEADNOTES ARE NOT AN OFFICIAL PRODUCT OF THE COURT, THEREFORE THEY ARE NOT DISPLAYED.]Page 1450

Tod L. Gamlen

, Baker McKenzie, of Palo Alto, CA, argued for plaintiff-appellant. With him on the brief was

David I. Roche

, of Chicago, IL.

Douglas A. Cawley

, Hughes Luce, L.L.P., of Dallas, TX, argued for defendants-cross appellants. With him on the brief was

Aubrey Nick

Pittman

Before MAYER,

Chief Judge

,^fn*RICH, NEWMAN,

Circuit Judges

, ARCHER,

Senior Circuit Judge

,^fn**MICHEL, PLAGER, LOURIE, CLEVENGER, RADER, SCHALL, BRYSON, and GAJARSA,

Circuit Judges

.

Opinion for the court filed by

Senior Circuit Judge

ARCHER, in which

Circuit Judges

RICH, MICHEL, PLAGER, LOURIE, CLEVENGER, SCHALL, BRYSON, and GAJARSA join;

Circuit Judge

RADER joins as to part IV. Concurring opinions filed by

Circuit Judges

PLAGER and BRYSON. OpinionsPage 1451concurring in the judgment filed by

Chief Judge

MAYER, which

Circuit

Judge

NEWMAN joins, and

Circuit Judge

RADER. Additional views filed by

Circuit Judge

NEWMAN, which

Chief Judge

MAYER joins.

ARCHER,

Senior Circuit Judge

[1] Cybor Corporation (Cybor) appeals from the judgment of the United States District Court for the Northern District of California, 93-CV-20712 (Oct. 31, 1995), that Cybor pump, Model 5226, infringes the claims of U.S. Patent No. 5,167,837 (the '837 patent), currently owned by FAStar, Ltd. and exclusively licensed to FAS Technologies, Inc. (collectively FAS). FAS cross-appeals the judgment as to the damages calculation, the denial of enhanced damages, and the refusal to declare the case exceptional and to award attorney fees. A panel heard oral argument on January 29, 1997. Before its opinion issued, however, this court

sua sponte

on September 5, 1997 ordered that this case be decided in banc.

[2] We affirm the district court's judgment in its entirety. In so doing, we conclude that the Supreme Court's unanimous affirmance in

Markman v. Westview Instruments, Inc.

,116 S.Ct. 1384(1996) (

Markman II

), of our in banc judgment in that case fully supports our conclusion that claim construction, as a purely legal issue, is subject to

de novo

review on appeal.

See Markman v. Westview Instruments, Inc.

,52 F.3d 967,979, 34 USPQ2d 1321, 1329 (Fed. Cir. 1995) (in banc) (

Markman I

[3] BACKGROUND

[4] The '837 patent discloses a device and method for accurately dispensing industrial liquids. The primary use of the patented inventions is to dispense small volumes of liquid onto semiconductor wafers. Claim 1 is representative and reads:¹

1. In a device for filtering and dispensing fluid in a precisely controlled manner, the combination of:

first pumping means;

second pumping means in fluid communication with said first pumping means; and

filtering means between said first and second pumping means, whereby said first pumping means pumps the fluid through said filtering means to said second pumping means;

in which each of said first and second pumping means includes surfaces that contact the fluid, said surfaces being of materials that are non-contaminating to industrial fluids which are viscous and/or high purity and/or sensitive to molecular shear; and

comprising means to enable said second pumping means to collect and/or dispense the fluid, or both, at rates or during periods of operation, or both, which are independent of rates or periods of operation, or both, respectively, of said first pumping means.

[5] Figure 2 of the patent illustrates a preferred embodiment of the invention:Page 1452

[6] [EDITORS' NOTE: FIGURE 2 IS NOT ELECTRONICALLY NON-TRANSFERRABLE.]

In the preferred embodiment, the fluid to be filtered enters the system through tubing 14 and travels through the ball valve 24 to the first pumping means 30 via tubing 41. The pumping means 30 then pumps the liquid back through the ball valve 24, which rotates to close tubing 14 and open tubing 102. The liquid then flows to the filter means 100 in which it is filtered. The filtered liquid (filtrate) then flows through tubing 116 and into the second pumping means 120. The filtrate can then be immediately dispensed, accumulated in the upper compartment 131 of the pumping means 120, or simultaneously accumulated and dispensed. The filtrate is dispensed in precise measurements by the second pumping means 120 through tubing 16 at rates and during periods of operation that are independent of the first pumping means 30.

[7] The dual stage pump manufactured by Cybor is used for the same purpose as that of the patented invention — application of liquid in precise, small volumes onto semiconductor wafers. It is illustrated below:Page 1453

[8] [EDITORS' NOTE: THE FIGURE ON PAGE 1453 IS NOT ELECTRONICALLY NON-TRANSFERRABLE.]

In the accused device, pump 1 draws the liquid from a source bottle through a feed line and through a three-way solenoid valve. The solenoid valve then closes the passage to the source bottle and opens the line to the filter, allowing pump 1 to deliver the liquid to the filter. After the liquid passes through the filter, the filtrate flows to a reservoir external to pump 2, where it accumulates until dispensed by pump 2. It is uncontested that the external reservoir, coupled with the second pump, allows the system to accumulate, dispense, or simultaneously accumulate and dispense filtrate. The filtrate leaves the reservoir through another three-way solenoid connector, or valve, and enters the second pump. The solenoid valve then closes the passage to the reservoir and opens the dispense port, through which the second pump dispenses the filtrate back through the solenoid valve and on through the dispensing port and line.

[9] On September 23, 1993, Cybor sued FAS for a declaratory judgment of non-infringement, invalidity, and unenforceability of the '837 patent. FAS counterclaimed²for infringement of all twenty claims and sought damages and injunctive relief. The case proceeded to trial, and the jury found by special verdict that the claims were not invalid, that Cybor literally infringed all the claims except 11, 12, and 16, and that these three remaining claims were infringed under the doctrine of equivalents. The jury determined the infringement to be willful for all claims except claim 16.

[10] After the jury rendered its liability verdict, the district court denied Cybor's renewed motion for Judgment as a Matter of Law (JMOL) that it did not infringe the '837 patent, and also denied FAS's motion for an exceptional case award of attorney fees pursuant to35 U.S.C. § 285(1994). Prior to the entry of final judgment, however, this court decided

Markman I

, which held that claim construction is a matter of law to be determined exclusively by the judge. Cybor then filed a motion for reconsideration of its JMOL motion in light of that decision, but the district court denied reconsideration. After further proceedings on damages, the district court on October 11, 1995, filed its Findings of Fact and Conclusions of Law permanently enjoining Cybor from making, using, or selling its system, awarding FAS $130,912 in damages, and denying FAS's motion for enhanced damages under35 U.S.C. § 284(1994). The district court entered itsPage 1454final judgment on October 31, 1995, and these appeals followed.

[11] DISCUSSION

[12] A. This court reviews a denial of a motion for JMOL

de novo

by reapplying the JMOL standard.

See Read Corp. v. Portec, Inc.

,970 F.2d 816,821, 23 USPQ2d 1426, 1431 (Fed. Cir. 1992). Under this standard, we can reverse a denial of a motion for JMOL only if the jury's factual findings are not supported by substantial evidence or if the legal conclusions implied from the jury's verdict cannot in law be supported by those findings.

See Kearns v. Chrysler Corp.

,32 F.3d 1541,1547-48, 31 USPQ2d 1746, 1751 (Fed. Cir. 1994).

[13] An infringement analysis involves two steps. First, the court determines the scope and meaning of the patent claims asserted,

see

Markman II

,116 S.Ct. at 1387, and then the properly construed claims are compared to the allegedly infringing device,

see Read Corp.

,970 F.2d at 821, 23 USPQ2d at 1431. Although the law is clear that the judge, and not the jury, is to construe the claims, this case presents the issue of the proper role of this court in reviewing the district court's claim construction.

[14] In

Markman I

, we held that, because claim construction is purely a matter of law, this court reviews the district court's claim construction

de novo

on appeal.

See Markman I

,52 F.3d at 979,981, 34 USPQ2d at 1329, 1331. In reaching this conclusion, we recognized that

[t]hrough this process of construing claims by, among other things, using certain extrinsic evidence that the court finds helpful and rejecting other evidence as unhelpful, and resolving disputes
en

route
to pronouncing the meaning of claim language as a matter of law based on the patent documents themselves, the court is
not
crediting certain evidence over other evidence or making factual evidentiary findings. Rather, the court is looking to the extrinsic evidence to assist in its construction of the written document, a task it is required to perform. The district court's claim construction, enlightened by such extrinsic evidence as may be helpful, is still based upon the patent and prosecution history. It is therefore still construction, and is a matter of law subject to
de

novo
review.

[15]

Id.

at 981, 34 USPQ2d at 1331 (emphasis in original and footnote omitted).

[16] After the Supreme Court's decision in

Markman II

, panels of this court have generally followed the review standard of

Markman I. See

Serrano v. Telular Corp.

,111 F.3d 1578, 42 USPQ2d 1538 (Fed. Cir. 1997);

Alpex Computer Corp. v. Nintendo Co.

,102 F.3d 1214, 40 USPQ2d 1667 (Fed. Cir. 1996);

Insituform Techs., Inc. v. CAT Contracting, Inc.

,99 F.3d 1098, 40 USPQ2d 1602 (Fed. Cir. 1996);

General Am. Transp. v.

Cryo-Trans, Inc.

,93 F.3d 766, 39 USPQ2d 1801 (Fed Cir. 1996). In some cases, however, a clearly erroneous standard has been applied to findings considered to be factual in nature that are incident to the judge's construction of patent claims.

See Eastman Kodak Co. v. Goodyear Tire

Rubber Co.

,114 F.3d 1547,1555-56, 42 USPQ2d 1737, 1742 (Fed. Cir. 1997);

Serrano

,111 F.3d at 1586, 42 USPQ2d at 1544, (Mayer, J., concurring);

Wiener v. NEC Elecs. Inc.

,102 F.3d 534,539, 41 USPQ2d 1023, 1026 (Fed. Cir. 1996);

Metaullics Sys. Co. v. Cooper

,100 F.3d 938,939, 40 USPQ2d 1798, 1799 (Fed. Cir. 1996).³We ordered that this case be decided in bancPage 1455to resolve this conflict, and we conclude that the

de novo

standard of review as stated in

Markman I

remains good law.

[17] B. The Supreme Court framed the question before it in

Markman II

in the alternative: "whether the interpretation of a so-called patent claim . . .

is a matter of law

reserved entirely for the court, or subject to a Seventh Amendment guarantee that a jury will determine the meaning of any disputed term of art about which expert testimony is offered."

Markman

,116 S.Ct. at 1387(emphasis added). When it answered that question by stating that "[w]e hold that the construction of a patent, including terms of art within its claim, is exclusively within the province of the court,"

id.

, the Court held that the totality of claim construction is a legal question to be decided by the judge. Nothing in the Supreme Court's opinion supports the view that the Court endorsed a silent, third option — that claim construction may involve subsidiary or underlying questions of fact.⁴To the contrary, the Court expressly stated that "treating interpretive issues as

purely legal

will promote (though not guarantee) intrajurisdictional certainty through the application of

stare

decisis

on those questions not yet subject to interjurisdictional uniformity under the authority of the single appeals court."

Id.

at 1396 (emphasis added);

see also Pullman-Standard v.

Swint

,456 U.S. 273,287-88(1982).

[74] This court may not, however, independently review the constituent facts or disregard the jury's findings, absent proof that they lack sufficient evidence that "a reasonable mind might accept as adequate to support" them.

Consolidated Edison Co. v. NLRB

,305 U.S. 197,229Page 1466(1938);

see Genentech, Inc. v. Wellcome Found. Ltd.

,29 F.3d 1555,1565, 31 USPQ2d 1161, 1169 (Fed. Cir. 1994). Nor may we construe a claim in a manner that is inconsistent with our function as a court of review; we cannot divine new interpretations of terms in a claim or make findings of fact from a record that cannot support them.

See Avia Group Int'l, Inc.

v. L.A. Gear California, Inc.

,853 F.2d 1557,1561, 7 USPQ2d 1548, 1551 (Fed. Cir. 1988).

[75] Sometimes it may be necessary for an appellate court to pronounce new legal principles during an appeal. However, even if this court identifies a question of claim construction as one of law — though its resolution is relevant to only the particular litigation or document — it cannot elevate the activity to one of determining legal principles, as is for example, statutory construction.

See

Markman

,116 S.Ct. at 1396("[I]ssue preclusion could not be asserted against new and independent infringement defendants even within a given jurisdiction . . . .");

In re

Freeman

,30 F.3d 1459,1466, 31 USPQ2d 1444, 1450 (Fed. Cir. 1994);

Jackson Jordan, Inc. v. Plasser American Corp.

,747 F.2d 1567,1574-75, 224 USPQ 1, 5-6 (Fed. Cir. 1984) (second alleged infringer not bound by prior claim construction unless it had,

inter alia

, a full and fair opportunity to litigate the construction in the first infringement action). Thus, regardless of the labels we attach to these questions, without the benefit of a full record from the trial court, it is neither the function of this court nor is it within our capacity as an appellate court to adopt new interpretations, most especially not if the interpretation under review is of terms informed by conflicting evidence. Such indiscriminate and conclusive review deprives the parties of important substantive and procedural mechanisms provided in the trial courts, where interpretation can be informed by additional discovery and expert testimony, and where it can be checked by appellate review as a matter of right. If claim construction is only a question of law to be reviewed by this court

de novo

, then the absence of review as a matter of right over

our

claim constructions, which may be new and unsupported by legal analysis, or may never have been tested by the adversarial process, would transform this court into a trial court of first and usually last resort.

[76] II.

METHOD OF REVIEW

[77] To determine whether a patent has been infringed, a district judge must partake of a two-step analysis: (1) construction of the claims to determine their legal effect by examining and resolving,

inter alia

, factual disputes over the meaning and scope of technical words or terms of art used in the patent,

see Fromson

,132 F.3d at 1442, 45 USPQ2d at 1272;

Markman

,52 F.3d at 999, 34 USPQ2d at 1347 (Newman, J., dissenting); and (2) a comparison of the properly construed claims to the accused device,

see Carroll Touch, Inc. v. Electro Mechanical Sys., Inc.

,15 F.3d 1573,1576, 27 USPQ2d 1836, 1839 (Fed. Cir. 1993). The first step, construction of the claim, is ultimately a question for the judge.

See Markman

,116 S.Ct. at 1395("So it turns out here, for judges, not juries, are the better suited to find the acquired meaning of patent terms.") In construing the claims, a judge looks to the claims themselves, the specification, the prosecution history of the patent,

see

Minnesota Mining and Mfg. Co., v. Johnson Johnson Orthopaedics, Inc.

,976 F.2d 1559,1566, 24 USPQ2d 1321, 1327 (Fed. Cir. 1992), and, if necessary, extrinsic evidence for information or to resolve disputes over the meaning of terms,

see Texas Instruments, Inc. v. United States Int'l

Trade Comm'n

,988 F.2d 1165,1171, 26 USPQ2d 1018, 1023 (Fed. Cir. 1993). Although

Markman

,116 S.Ct. 1384, requires the judge to make the ultimate determination about the meaning and legal consequence of a claim, it does not prohibit him from submitting subsidiary factual disputes to a jury, even if it does not encourage it.

[78] The judge follows the same first step to construe claims containing means-plus-function limitations under35 U.S.C. § 112(6) (1994).

See

Alpex

,102 F.3d at 1220, 40 USPQ2d at 1672;

Intellicall, Inc. v.

Phonometrics, Inc.

,952 F.2d 1384,1388, 21 USPQ2d 1383, 1387 (Fed. Cir. 1992). However, to complete the construction of these means-plus-function terms, the judge must look to the structures, materials, or actsPage 1467disclosed in the patent's specifications and to their equivalents.

Id.

,952 F.2d at 1388, 21 USPQ2d at 1387. To determine the scope of such equivalents, the district court must resolve questions of fact by resorting to the expertise of the fact finder.

Cf. Markman

,52 F.3d at 977n. 8, 34 USPQ2d at 1337, n. 8 (expressly declining to reach "the issue of whether a determination of equivalents under § 112, para. 6 is a question of law or fact");

In re Hayes Microcomputer Prods., Inc.

,982 F.2d 1527,1541-43, 25 USPQ2d 1241, 1253 (Fed. Cir. 1992) ("This list [of factors that may be considered when determining the scope of a means-plus-function limitation] is not exhaustive and reasonable inferences by the fact finder are appropriate.");

King Instruments Corp.

v. Otari Corp.

,767 F.2d 853,862-63, 226 USPQ 402, 408-09 (Fed. Cir. 1985);

Palumbo v. Don-Joy Co.

,762 F.2d 969,975-76, 226 USPQ 5, 8 (Fed. Cir. 1985) ("Whether that accused device is a § 112 equivalent . . . is a question of fact.");

D.M.I., Inc. v. Deere Co.

,755 F.2d 1570,1575, 225 USPQ 236, 239 (Fed. Cir. 1985). For pragmatic reasons, the resolution of this factual determination is often made at the same time the fact finder determines infringement (step two, described below).

[79] The second step of the infringement analysis requires a factual comparison of the claimed invention to the accused device, which is done by the fact finder.

See Winans v. Denmead

, 56 U.S. (15 How.) 330, 338 (1853). To prove literal infringement, the patentee must show that the accused device contains every limitation in the asserted claims.

See

Dolly, Inc. v. Spalding Evenflo Cos.

,16 F.3d 394,397, 29 USPQ2d 1767, 1769 (Fed. Cir. 1994). If tried to a jury, it is the jury's factual findings on infringement that are reviewed by this court for lack of substantial evidence,

see

Genentech

,29 F.3d at 1565, 31 USPQ2d at 1168-69, as part of this court's reapplication of the standard for judgment as a matter of law.

[80] A claim of infringement under the doctrine of equivalents modifies this second step by requiring that the fact finder determine whether differences between particular elements of the accused device and the asserted claims are insubstantial.

See

Warner-Jenkinson Co. v. Hilton

Davis Chem. Co.

,117 S.Ct. 1040,1054(Mar. 3, 1997). However, because they have separate origins, purposes, and applications, determining equivalence under paragraph 112(6) requires an analysis different from that used to determine equivalence under the doctrine of equivalents.

See

Alpex

,102 F.3d at 1222, 40 USPQ2d at 1673 ("Under § 112, the concern is whether the accused device, which performs the claimed function, has the same or an equivalent structure as the structure described in the specification corresponding to the claim's means. Under the doctrine of equivalents, on the other hand, the question is whether the accused device is only insubstantially different than the claimed device.") (internal citations omitted).

[81] After the judge construes the means-plus-function limitations identifying structures, materials, or acts described in the patent's specification, and their equivalents as determined by the fact finder (step one, described above), the judge gives the construed claims to the fact finder, in this case a jury, for a determination of infringement.

See D.M.I.

,755 F.2d at 1575, 225 USPQ at 239. For literal infringement, the fact finder must determine whether the accused device performs an identical function to the one recited in the means-plus-function clause.

See

Pennwalt Corp. v. Durand-Whayland, Inc.

,833 F.2d 931,934, 4 USPQ2d 1737, 1739 (Fed. Cir. 1987) (if the identical function is not performed, literal infringement is not possible). If the identical function is performed, the fact finder must then determine whether the accused device utilizes the same structure or materials as described in the specification, or their equivalents.

[82] Just as the fact finder's infringement analysis differs between equivalence under paragraph 112(6) and the doctrine of equivalents, so too differs the analytical effect of statements made during the prosecution of the patent on construction of the claims. Under paragraph 112(6), a statement made during prosecution may confine the range of equivalent structures, materials, or acts that are directly claimed by the patent. However, in the context of a doctrine of equivalents analysis, the patentee seeks protection beyondPage 1468that claimed by the patent directly. As such, the judge's construction of the claims — which includes the interpretation of claim terms — may not be sufficient to remove from the jury's consideration all subject matter that was disclaimed during prosecution.

[83] Prosecution history estoppel addresses this problem by excluding equivalents surrendered during prosecution. Under this doctrine, statements made to overcome rejections based, as here, on prior art estop the patentee from extending its right to exclude others from making, using, or selling subject matter known to be insubstantially different from, or interchangeable with, claimed elements at the time of the alleged infringement.

Warner-Jenkinson

,117 S.Ct. at 1053. Although both forms of equivalence require the district court to examine the prosecution history as part of its construction of the claims, under the doctrine of equivalents, the judge gives the claim, properly construed to exclude disclaimed subject matter, to the jury and then, where appropriate, also instructs the jury on the possible range of equivalents that it may or may not consider due to prosecution history estoppel.

[84] III.

REVIEW

[85] As depicted in figure two of the patent,

ante

at 3 [maj. opn], the '837 patent discloses a dual-stage pump. It claims a first pumping means that pumps fluid through a filtering means "to" a "second pumping means." It also claims a "means to enable said second pumping means to collect and/or dispense the fluid, or both," at rates or during periods that are independent of the operation of the first pumping means. As a result of this structure, the pump described in the '837 patent is able to accumulate fluid for later dispense, dispense fluid immediately, or partially accumulate and partially dispense fluid in precise measurements and at precise times. The preferred embodiment describes a second pumping means where the second pump collects and dispenses the fluid from its own internal reservoir.

[86] Like the pump disclosed in the '837 patent, Cybor Corporation's Model 5226 dual-stage pump also allows users to pump or dispense highly accurate amounts of liquid chemicals in increments as small as 0.1 microliter. Both pumps are primarily used for accurately dispensing chemicals — such as photoresist and polimide — onto semiconductor wafers during their fabrication.

[87] Of relevance to this appeal, in construing the '837 patent the district judge interpreted the disputed term "to" and submitted the term to the jury for a determination of infringement. The judge also submitted the terms "second pumping means," "means to enable said second pumping means," and "or both" to the jury as means-plus-function terms, along with structures in the '837 patent's specification, for a determination of infringement. The judge left the task of considering prosecution history estoppel to the jury.²The jury found that Cybor's Model 5226 pump literally infringed claims 1-10, 13-15, and 17-20, and that it infringed claims 11, 12, and 16 under the doctrine of equivalents. It is unclear which combination of components in Cybor's Model 5226 pump the jury found to infringe claims 1-10, 13-15, and 17-20. It may have interpreted "second pumping means" in such a way that it found either Cybor's second pump or the combination of its second pump and its external reservoir to be equivalent structures to those provided in the specification of the '837 patent corresponding to the "second pumping means." Likewise, the jury may have interpreted "means to enable said second pumping means" in such a way that it found either Cybor's external reservoir or the combination of its external reservoir and its second pump to be equivalent structures to those provided in the specification of the '837 patent corresponding to the "means to enable said second pumping means." In total, there are five possible combinations of claim term interpretations and findings of paragraph 112(6) equivalents that would have led the jury to its infringement verdict.Page 1469

[88] Cybor renewed its earlier motion for judgment as a matter of law pursuant to Rule 50(b) and for a new trial pursuant to Rule59of the Federal Rules of Civil Procedure, on the basis that no reasonable juror could find that its pump infringes the '837 patent. The court denied the motion, finding "that the jury's infringement verdict is supported by the evidence . . . the jury instructions were proper and the verdict was not against the clear weight of the evidence or contrary to the instructions." Cybor moved for reconsideration, arguing that this court's then recently issued

Markman

,52 F.3d 967, 34 USPQ2d 1321, required that the judge, and not the jury, interpret all the claims. The district court denied the motion and entered final judgment, from which Cybor appealed.

[89] On appeal, Cybor argues that had the district court properly analyzed the prosecution history of the '837 patent, it would have excluded reservoir structures like Cybor's from consideration as an equivalent under paragraph 112(6). Cybor further argues that the judge would have instructed the jury not to consider its reservoir when determining whether Cybor's second pump has the same or an equivalent structure as the structure in the portions of the '837 patent's specification corresponding to the second pumping means. Without its reservoir, Cybor argues that its second pump cannot infringe the "second pumping means" limitation, the "or both" functional limitation, or the filter means "to" second pumping means limitation. Cybor also argues that the district judge erred in failing to identify the corresponding structures in the specification, and in permitting the judge to consider the effect of statements made during prosecution of the '837 patent.

[90] FAS responds that the district court properly considered and rejected Cybor's argument about the prosecution history of the '837 patent, that it properly construed the necessary claims, and that it properly submitted them along with relevant corresponding structures — as described in the specification — to the jury for a determination of infringement. FAS further argues that the district court was not obliged, either before or after

Markman

, to submit complete claim constructions to the jury so long as the judge's ultimate claim construction is supported by the jury's factual findings, presumed or expressed, regarding disputed claim terms, and so long as the judge later evaluates and sustains the jury's factual findings.

[91] Claim 1 of the '837 patent contains three disputed limitations and is representative of how these limitations are used, where they appear throughout the 20 asserted claims:

In a device for filtering and dispensing fluid in a precisely controlled manner, the combination of:

first pumping means;

second pumping means
in fluid communication with said first pumping means; and

filtering means between said first and
second

pumping means
, whereby said first pumping means pumps the fluid through said filtering means
to
said second pumping means;

in which each of said first and second pumping means includes surfaces that contact the fluid, said surfaces being of materials that are non-contaminating to industrial fluids which are viscous and/or high purity and/or sensitive to molecular shear; and

comprising
means to enable said second pumping
means to collect and/or dispense the fluid,
or both
, at rate or during periods of operation, or both which are independent of rates or periods of operation, or both, respectively, of said first pumping means.

[92] '837 patent, col. 9, lines 45-61 (emphasis and formatting added). The specification of the '837 patent further describes the "second pumping means" as having tubing that connects the pump to the second incremental pump advancement means, col. 5, lines 49-52, a diaphragm inside the second pump, col. 6, lines 2-3, and a separate inlet passage and outlet passage, col. 7, lines 10-20.

[93] During prosecution, the inventors further limited the scope by making the following statements to overcome a prior art rejection that the claimed invention was unpatentable over Storkebaum et al., U.S. Patent No. 4,749,476.

[94] Additionally, Storkebaum specifically provides a separate container 12 for collectingPage 1470the permeate. Obviously, Storkebaum does not teach the collection of fluid in a second pumping means . . . . Storkebaum discloses a permeate collecting container 12 that is

separate

from the conveying pump 13. Nothing in Storkebaum discloses or makes obvious the claimed invention, nor the precise and flexible control provided by the second pump means of Claim 1.

[95] Given the nature and function of the Storkebaum container, these statements were made to distinguish the invention over the prior art. They confine the possible interpretation of terms in the claims under paragraph 112(6) and they may prevent FAS's desired use of the doctrine of equivalents.

See Warner-Jenkinson

,117 S.Ct. at 1051n. 7. However, in this case the limitation of possible equivalents extends only so far as was necessary to distinguish aspects of the invention's "second pumping means" from Storkebaum's external container. The statements do not require that the district judge provide the jury with more specific interpretations of claim terms because the inventors disclaimed the use of a separate, physically unattached reservoir that cannot achieve differential pumping rates between the two pumps by accumulating fluid in a reservoir — the function performed by the '837 patent's "means to enable said second pumping means."

[96] Storkebaum's separate container collects permeate and vents the fluid; it is designed to feed a conveying pump that is part of a big circulation loop, not a fluid dispensing device. Because the inventors never disclaimed an external reservoir that accumulates fluid to permit different pumping rates and because equivalence under paragraph 112(6) is a question of fact, the district court properly permitted the jury to consider the structure of Cybor's external reservoir as a possible equivalent, under paragraph 112(6), to structures in the '837 patent's specification that define the "second pumping means" and the "means to enable the second pumping means." It was also proper for the district court to permit the jury to consider Cybor's reservoir in measuring the substantiality of differences between its device and the invention claimed by the '837 patent, under the doctrine of equivalents.

[97] A.

"Second Pumping Means"

[98] "

Means to Enable Said Second Pumping Means"

[99] As to these two disputed limitations, each of the independent claims, except for claim 16, uses the term "second pumping means," which the court interpreted in means-plus-function language as: "a structure identical to the structure disclosed in the specification of the patent or the equivalent of that structure which performs the function of a fluid accumulator/dispense pump." The district court also interpreted the term "means to enable said second pumping means," which appears in each of the independent claims except claims 10, 16, and 17, in means-plus-function language, as: "a structure identical to the structure disclosed in the specification of the patent, or the equivalent thereof, which allows the second pumping means to [accumulate, dispense, and partially collect and dispense fluid at rates and during periods independent of the first pumping means]."

[100] Cybor argues that these means-plus-function elements should be limited to the exact structures disclosed in the claims and the specification of the '837 patent. However, paragraph 112(6) permits the disclosure of specific structures in the specification, without limiting protection to the disclosed structures.

See

35 U.S.C. ¶ 112(6) ("[S]uch claims shall be construed to cover the corresponding structure, materials, or acts described in the specification and equivalents thereto.");

D.M.I.

,755 F.2d at 1574, 225 USPQ at 238. Cybor is correct that the reservoir and the second pump in its dual-stage pump are not identical to the structure disclosed in the specification of the '837 patent; they contain a valve unlike the disclosed structure, and if uncoupled from the attached reservoir, the pump does not permit the partial accumulation and partial dispensing of fluid as contemplated by the term "flow through" in the '837 patent. However, as explained above, the prosecution history does not require the district court to uncouple the valve or separate the reservoir from the second pump before submitting the terms "second pumping means" and "means to enable said second pumping means" to the jury.Page 1471The '837 patent's preferred embodiment shows the reservoir inside the second pump, but nothing requires such a restriction, and limitations in the specification should not be read into the claims.

See Constant v.

Advanced Micro-Devices, Inc.

,848 F.2d 1560,1570-71, 7 USPQ2d 1057, 1064 (Fed. Cir. 1988). Finally, such a restriction would go against the clear weight of testimony submitted by FAS's expert witnesses, Clark, who was qualified as one skilled in the art of fluid dynamics, and Snodgrass and Gibson.

[101] "As in all cases involving assertions of equivalency, wherein the patentee seeks to apply its claims to structures not disclosed by the patentee, the court is required to exercise judgment."

Texas Instruments,

Inc. v. United States Int'l. Trade Comm'n

,846 F.2d 1369,1371, 6 USPQ2d 1886, 1889 (Fed. Cir. 1988). Here, the district court exercised its judgment, made a partial, though legally sufficient interpretation of these limitations, and presented them to the jury for resolution of factual disputes on the way to determining equivalents under paragraph 112(6). Based on these interpretations and the jury's verdict, we presume³

that the jury found that the combination of one of Cybor's Model 5016 pumps with the external reservoir it uses in its Model 5226 pump created a structural equivalent to the "second pumpiing means" or the "means to enable said second pumping means" claimed in the '837 patent and described by the specification under paragraph 112(6). Because we have not been shown that the jury lacked substantial evidence to support this finding of equivalents or infringement, we must affirm.

[102] However, if the court is correct that claim construction is purely and solely a question of law to be reviewed

de novo

on appeal, it could not affirm the judgment of infringement. Infringement was determined in this case by a jury at the same time that it was asked to construe these claims by resolving factual disputes about their meaning and to determine whether the scope of these claims should be limited by arguments made during prosecution of the patent. Ordinarily, a jury's verdict of infringement permits us to presume the existence of factual findings necessary to that verdict. But we are in no way entitled to presume factual findings or even to rely on the verdict of infringement where neither the jury, nor the judge on a motion for judgment as a matter of law, articulated a construction of the claims upon which the findings are premised. As explained above, there are five possible combinations of claim term interpretations and findings of paragraph 112(6) equivalents that could have led the jury to its infringement verdict. In light of the possibilities, it is difficult to imagine how the court can affirm the jury's finding of infringement based upon its own

de novo

claim construction, which merely presumes a claim construction by the district court and that admits of no deference to the findings of fact.

[103] The effect of allowing such a combination of presumptions in this case has been to deny Cybor meaningful review of anything more than the district judge's decision not to apply prosecution history estoppel, since it was the only legal determination that can be located outside of those presumptions. Not surprisingly, this is the decision Cybor contests most strenuously on appeal. The effect has also been to allow this court to presume that it made the same claim construction as the jury, without so much as articulating its own construction of these two claim terms, and then to presume that the jury's infringement finding is still valid. Penultimately, Cybor is left with little more than the ability to make presumptions as to our own claim interpretations in any motion it may file for reconsideration. Worse still is the message the court is sending to district courts: we will affirm a finding of infringement as long as the district court avoids articulating its construction of the claims — which coincidentally leaves us free to arrive at our own constructions — and as long as we can presume that the jury usedPage 1472our constructions to arrive at that finding of infringement.

[104] B.

"To"

[105] The second of these three disputed claim limitations, "pumps fluid through said filtering means to said second pumping means," is the only one that the district court did not analyze as part of a means-plus-function limitation. Cybor argued that the fluid has to be pumped directly to the second pump. FAS maintains that it is enough that the fluid merely reaches the second pump. The district court interpreted the term "to" as pumping "towards and with a destination of" the second pump and left the determination of infringement to the jury. Absent its prosecution history estoppel argument, there remains little to Cybor's interpretation of this claim limitation. FAS presented sufficient expert testimony from Gibson and Clark that the fluid must merely be pumped "ultimately" to the "second pumping means." This evidence is consistent with the expert testimony of Snodgrass and Gibson that the "to" limitation requires only a designed or dedicated pathway between the two pumping means, which Cybor's device possesses. Because all experts were consistent in their testimony about the meaning of terms to one skilled in the art, there was no occasion here for the court to resolve a factual dispute over the meaning of a term en route to their interpretation. Moreover, because the interpretation of this claim limitation describes Cybor's Model 5226 dual-stage pump, regardless of whether or not the reservoir is part of the second pumping means, no reasonable juror could use this as a basis for finding noninfringement, and I agree we can affirm this aspect of the district court's judgment.

[106] C.

"Or Both"

[107] The third disputed limitation, "or both" is contained within means-plus-function language, it describes a function of the "means to enable second pumping means," and it must be a function of Cybor's device if the fact finder is to consider equivalence under paragraph 112(6). Cybor argues solely that the inventor of the '837 patent disclaimed external reservoirs such as its own, by distinguishing Storkebaum. Thus the jury should not consider its external reservoir when it determines whether the Model 5226 dual-stage pump contains structural equivalents to each of the relevant limitations disclosed in the '837 patent. Given the prosecution history analysis and the jury's presumed finding that Cybor's reservoir and second pump contain equivalents of all the limitations to the "means to enable said second pumping means," Cybor's argument cannot stand. The jury had substantial evidence upon which to find that Cybor's reservoir and second pump together can collect, dispense, and both collect and dispense fluid, so its finding of infringement is also sufficient.

[108] IV.

JUDGMENT AS A MATTER OF LAW

[109] Finally, Cybor argues that

Markman

,52 F.3d 967, 34 USPQ2d 1321, requires that the judge determine the meaning of the claim before submitting it to the jury. However, that opinion said that the judge must determine the meaning of a claim, but that the meaning need not be established before the claims are submitted to the jury.

Markman

,52 F.3d at 981, 34 USPQ2d at 1331 (pronouncing the meaning of a claim "ordinarily can be accomplished by the court in framing its charge to the jury, but may also be done in the context of dispositive motions such as those seeking judgment as a matter of law.") The risk of waiting, of course, is that the jury's deliberative efforts on infringement may be rendered useless if the instruction was improper and the affected factual dispute was material to the verdict. Here, this happens only under the court's standard of review. Moreover, given the nature and interrelatedness of these disputed limitations and the underlying factual questions — whether the combination of Cybor's second pump and its reservoir is a paragraph 112(6) equivalent to the "second pumping means" or the "means to enable said second pumping means" — it is difficult to see how the district court could have better instructed the jury, absent the use of detailed and alternative special verdicts. Therefore, I see no reversible error in the district court's limited claim interpretations or its denial of Cybor's motion for judgment as a matter of law.Page 1473

[110] RADER,

Circuit Judge

, dissenting from the pronouncements on claim interpretation in the

en banc

opinion, concurring in the judgment, and joining part IV of the

en banc

opinion.

[111] The

en banc

court chooses this case, resolvable under the prosecution history estoppel doctrine, to state that it accords no deference to the district court's central role in patent litigation, namely claim interpretation. Yet, based on this court's unanimous concurrence in the judgment, the standard of review does not affect the outcome in this case. Accordingly, this case obscures what really is at stake when claim construction is subject to de novo review and appellate revision.¹

[112] In

Markman I

, this court

en banc

declared that claim interpretation resides solely with the judge. The Supreme Court agreed.

See Markman v.

Westview Instruments, Inc.

,116 S.Ct. 1384,1387(1996) (

Markman II

). By removing lay juries from complex technological decisions, these decisions promised to improve the predictability and uniformity of patent law.

See

Markman II

,116 S.Ct. at 1396.

[113] To evade the strictures of the Seventh Amendment,

Markman I

necessarily reasoned that claim construction is purely a matter of law. As a pure question of law, claim construction became subject to plenary appellate review. Because jury involvement remained the focus of

Markman

, the Supreme Court did not address appellate review of claim construction. Instead the Supreme Court repeatedly intimated that claim construction was not a purely legal matter.

See, e.g.

Markman II

,116 S.Ct. at 1390(calling the construction of a term of art following receipt of evidence a "mongrel practice");

id.

at 1395 (suggesting that claim interpretation "`falls somewhere between a pristine legal standard and a single historical fact'" (quoting

Miller v. Fenton

,474 U.S. 104,114(1985)));

id.

at 1396 ("notwithstanding [claim construction's] evidentiary underpinnings"). Nonetheless, in the time since

Markman II

, this court has repeatedly extolled its own authority to "review the issue of claim interpretation independently

without deference

to the trial judge."

Exxon Chem. Patents, Inc. v. Lubrizol Corp.

,64 F.3d 1553,1556, 35 USPQ2d 1801, 1803 (Fed. Cir. 1995) (

Lubrizol

) (emphasis added);

see also Hoechst Celanese Corp. v. BP Chem. Ltd.
,78 F.3d 1575,1578, 38 USPQ2d 1126, 1128 (Fed. Cir.),
cert. denied
,117 S.Ct. 275(1996). Indeed, at one point, this court noted that its law requires "independent determination of the construction of the claims, as a matter of law, unencumbered by the trial process."
Festo Corp. v. Shoketsu Kinzoku

Kogyo Kabushiki Co.
,72 F.3d 857,863, 37 USPQ2d 1161, 1165 (Fed. Cir. 1995),
vacated and remanded on

other grounds
,117 S.Ct. 1240(1997). Unencumbered by the trial process? Far from an encumbrance, the Supreme Court suggests that the trial should be the "main event."
Wainwright v. Sykes
,433 U.S. 72,90(1977).

[114] Because jury issues dominated

Markman I

, this court has yet even to receive briefing and oral argument on the proper standard of review for a trial court's claim construction. Nonetheless this court relies on its earlier

en banc

decision,

Markman I

,52 F.3d at 979, to make claim construction purely a question ofPage 1474law, subject to independent appellate review without deference to or encumbrance by the trial process. To my eyes, this rejection of the trial process as the "main event" will undermine, if not destroy, the values of certainty and predictability sought by

Markman I

[115] The question of the proper standard of review seems an esoteric legal topic of interest only to law professors and appellate judges. In most cases, however, the review standard influences greatly both the trial judges who preside over the trial process and patent practitioners who must advise clients to accommodate their business plans to an uncertain legal regime.

[116] From the vantage point of trial judges,

Markman I

dictates many deviations from the normal procedural course for litigation.²Perhaps the central deviation, however, affects the trial court's discretion to use expert testimony. When confronted with sophisticated technology, district court judges often seek testimony from experts to help them understand and interpret the claim. Under the guise of setting standards for claim construction, this court instructs experienced trial judges that they may use experts to understand, but not to interpret, the claim terms. As a matter of logic, this instruction is difficult to grasp. What is the distinction between a trial judge's understanding of the claims and a trial judge's interpretation of the claims to the jury? Don't judges instruct the jury in accordance with their understanding of the claims? In practice, how does this court's lofty appellate logic work? As this court acknowledges, a trial court must often resort to experts to learn complex new technologies.

See, e.g.

Markman I

,52 F.3d at 986. What happens when that learning influences a trial judge's interpretation of thePage 1475claim terms? Are trial judges supposed to disguise the real reasons for their interpretation? How will this perverse incentive to "hide the ball" improve appellate review?

[117] As a matter of legal analysis, the

en banc

court's direction to trial judges is equally hard to justify. The objective of claim interpretation is to discern the meaning of the claim terms to one of ordinary skill in the art at the time of invention.

See

Multiform

Desiccants, Inc. v. Medzam, Ltd.

,133 F.3d 1473,1477, 45 USPQ2d 1429, 1432 (Fed. Cir. 1998) ("It is the person of ordinary skill in the field of the invention through whose eyes the claims are construed."). What then defeats the relevance of the testimony of one of skill in the art at the time of invention? Of course this relevant testimony must not conflict with or attempt to trump contemporaneous intrinsic evidence from the patent document itself,

see Vitronics Corp. v. Conceptronic, Inc.

,90 F.3d 1576,1582-83, 39 USPQ2d 1573, 1576-77 (Fed. Cir. 1996), but both trial and appellate judges are poised to halt that abuse. Moreover, by assigning claim interpretation to the judge,

Markman II

has already corrected the major source of the problem with experts, namely their ability to influence lay jurors with the strength of their resumes rather than the strength of their reasoning. In any event, it seems a contradiction to bar those of skill in the art at the time of invention from a search for the meaning of terms to one of skill in the art at the time of the invention. In effect, the

en banc

opinion has

sub silentio

redefined the claim construction inquiry as "how a lawyer or judge would interpret the term."

[118] District courts have already expressed their frustration with the strictures of

Markman I:

When two experts testify differently as to the meaning of a technical term, and the court embraces the view of one, the other, or neither while construing a patent claim as a matter of law, the court
has
engaged in weighing evidence and making credibility determinations . . . . But when the Federal Circuit Court of Appeals states that the trial court does not do something that the trial court does and must do to perform the judicial function, the court knowingly enters a land of sophistry and fiction.

[119]

Lucas Aerospace, Ltd. v. Unison Indus., LP

,890 F. Supp. 329,333-34n. 7, 36 USPQ2d 1235, 1239 n. 7 (D. Del. 1995);

see also Tura

,112 F.3d at 1160n. 7. Understanding that the law must not change from case to case or from circumstance to circumstance, a New York district court applied the Federal Circuit's claim interpretation in a separate infringement action involving the same patent. After trial, the defendant appealed. This time the Federal Circuit reversed the district court's claim interpretation.

See Tura

,112 F.3d at 1149("We conclude that the district court did err in

its

claim construction.") (emphasis added). Although this court referred to the New York district court's "error," the Federal Circuit had in fact reversed itself.

[127] One potential trial court response to the

CVI/Beta

problem might be the issuance of "tentative" claim constructions as a matter of law.

See

International Communications Materials, Inc. v. Ricoh Co., Ltd.

,108 F.3d 316, 41 USPQ2d 1957 (Fed. Cir. 1997). This response, of course, would further frustrate the parties' desire to receive a certain claim construction as early as possible.

[128] Regardless, if the Federal Circuit's reading of the very same claim can vary from one appeal to the next, every patent litigant has an incentive to appeal every action to the Federal Circuit in hopes that the statistics will hold up and eventually the appellate court will reverse. Even the Federal Circuit's claim interpretations as questions of law are not certain. Is this the "uniformity" outlined by the Supreme Court in

Markman II

III.

[129] Because patent trial practitioners understand the distinct prospect of overturning trial court results on appeal, the trial arena loses some of its luster as the center stage of the dispute resolution drama. Instead the trial court becomes a ticket to the real center stage, the Court of Appeals for the Federal Circuit. Taking a cue from the Supreme Court, this court would more wisely take a functional approach to setting a standard of review for claim construction.

[130] In

Markman II

, the Supreme Court noted that neither history nor precedent provided "clear answers" about the role of the jury and the factual or legal nature of claim construction.116 S.Ct. at 1395. Therefore, the Court pursued a functional inquiry to determine whether the judge or jury could best balance the complexities of claim construction.

See id.

A similar functional inquiry might best clarify the roles of the trial and appellate benches during claim interpretation.

[131] The Supreme Court has provided some guidelines for such a functional approach. The Court counsels appellate courts to defer "when it appears that the district court is `better positioned' than the appellate court to decide the issue in question or that probing appellate scrutiny will not contribute to the clarity of legal doctrine."

Salve

Regina College v. Russell

,499 U.S. 225,233(1991). At another point, the Court cautions: "[T]he reviewing attitude that a court of appeals takes toward a district court decision should depend upon `the respective institutional advantages of trial and appellate courts.'"

First Options

of Chicago, Inc. v. Kaplan

,514 U.S. 938,948(1995) (quoting

Salve

Regina

,499 U.S. at 233).

[132] Applying this general counsel, the trial judge enjoys a potentially superior position to engage in claim interpretation. For the complex case where the claim language and specification do not summarily dispose of claim construction issues, the trial court has tools to acquire and evaluate evidence that this court lacks. Trial judges can spend hundreds of hours reading and rereading all kinds of source material, receiving tutorials on technology from leading scientists, formally questioning technical experts and testing their understanding against that of various experts, examining on site the operation of the principles of the claimed invention, and deliberating over the meaning of the claim language. If district judges are not satisfied with the proofs proffered by the parties, they are not bound to a prepared record but may compel additional presentations or even employ their own court-appointed expert.

[133] An appellate court has none of these advantages. It cannot depart from the record of the trial proceedings. To properly marshal its resources, the appellate bench mustPage 1478enforce strict time and page limits in oral and written presentations.⁵Moreover a sterile written record can never convey all the nuances and intangibles of the decisional process. Indeed a careful consideration of the institutional advantages of the district court would counsel deference. This court's categorical response that claim interpretation involves no factual assessments does not advance a functional analysis of trial and appellate roles in claim construction. As a matter of fact (so to speak), claim construction requires assessment of custom and usage in the relevant art, assessment of events during prosecution, assessment of the level of ordinary skill in the art, assessment of the understanding of skilled artisans at the time of invention — to name just a few factual components of the complex process of claim interpretation. A careful functional analysis counsels deference for district court claim interpretations.

IV.

[134] The Supreme Court may have offered a path out of this predicament. At least three times in

Markman II

, as noted earlier, the Court alluded to the factual component of claim interpretation. At no point did

Markman

address the appropriate standard of review. Nonetheless this court misses the opportunity to improve certainty in patent practice by giving appropriate deference to trial court claim interpretations, particularly in complex cases. If this court accords more deference to trial court interpretations in the complex cases, soon the district courts will provide the desired certainty early in the process. At that point,

Markman

will fulfill its promise. Administration of patent law will move toward less costly disputes and earlier settlements.

[135]

Markman I

set out to improve patent law administration by removing uncertainties from the dispute resolution process (the chief uncertainty, of course, being jury results). Inadvertently the reasoning in

Markman I

has postponed the point of certainty to the extreme end of the judicial process. This delay both disrupts the orderliness of trials and practitioners' hopes for more efficient and earlier claim constructions. The Supreme Court removed the jury uncertainty with its decision and, by recognizing a factual component in claim interpretation, provided a way for this court to accomplish much of its early goals. By according some deference where appropriate, this court can restore the trial court's prominence in the claim interpretation function and bring again more certainty at an earlier stage of the judicial process. Applying the Supreme Court's reasoning for habeas proceedings to claim construction, "adoption of [a rule of appropriate deference] . . . will have the salutary effect of making the [district court's] trial on the merits the `main event,' so to speak, rather than a `tryout on the road' for what will later be the determinative [appeal to the Federal Circuit]."

Wainwright v. Sykes

,433 U.S. at 90. This certainty, in turn, would stimulate more settlements and efficient decision making — the promise of

Markman I

. With this reasoning in mind, I respectfully dissent from the claim interpretation pronouncements of the

en banc

opinion, concur in the judgment, and join only part IV of the

en banc

opinion. United States Court of Appeals for the Federal Circuit

NEWMAN,

Circuit Judge

, with whom Chief Judge MAYER joins; additional views.

[136] As this case illustrates, perfection is elusive in the aftermath of the Federal Circuit's decision in

Markman v. Westview Instruments, Inc.

,52 F.3d 967, 34 USPQ2d 1321 (Fed. Cir. 1995) (en banc),

aff'd

,116 S.Ct. 1384, 38 USPQ2d 1461 (1996). The expectation of greater stability in the application of patent law — thus enhancing consistency in result, reducing the cost of litigation, and indeed reducing litigation by diminishing the uncertainties of jury trials — has not been well achieved.Page 1479

[137] Most of the shortfalls between expectation and reality arise from the manner of implementation of our de novo authority for claim interpretation. I cite three principal areas. The first area relates to the treatment of certified questions. Although the district courts have extended themselves, and so-called "

Markman

hearings" are common, this has not been accompanied by interlocutory review of the trial judge's claim interpretation. The Federal Circuit has thus far declined all such certified questions. Indeed, the certified question issue was an early warning of the difficulties that could flow from premature claim interpretation, for it was often apparent from the petition that the claims could not be finally and correctly interpreted without evidence beyond the patent documents. The absence of extrinsic evidence, of resolution of conflicting positions, and of detailed analysis and findings by the trial judge, inhibited claim interpretation by certified question. Thus, instead of conducting the expected dispositive de novo review, we simply declined the question. The possibility of early finality to claim interpretation has not materialized, with two untoward consequences; first, the district court has had to conduct a perhaps unnecessary trial; and second, the eventual issuance of a new claim interpretation by the Federal Circuit, on appeal after final judgment, has sometimes required a second trial of the issue of infringement. None of these consequences comports with our insistence that claim interpretation is purely a matter of law, that it needs no findings at trial, and that it will be decided de novo by the Federal Circuit.

[138] The second area of disappointed expectations has flowed from the unexpectedly creative de novo claim interpretations that the Federal Circuit has issued in a few cases. This unpredictability in administration of the law of patent claiming has added a sporting element to our bench. It has not only released appellants' imaginations on appeal, but it will surely add complexity to future trials, as lawyers attempt to guard against the judicial imagination.

[139] A third concern, although rare in occurrence, is of great significance, for even one case wherein the Federal Circuit has deemed itself unconstrained by its own prior interpretation of the same patent removes finality and encourages relitigation of every patent. The promise of uniformity and finality, flowing from decisions of national effect, is a failed promise if we are not bound by stare decisis in our own claim interpretation.

[140] These flaws are of serious concern, no less because they are of our own making. They are not irremediable, although remedy may require a larger vision than we possess. However, today's en banc opinion adds another encumbrance to the procedures for interpretation of claims, further inhibiting fruition of the

Markman

expectation. When the issues in litigation involve complex questions of science and technology, a special effort is required of the judicial process.¹In litigation of patent disputes the nature of the evidence that is received and considered, the balance between the trial and appellate functions, and the evidentiary rules governing opinion testimony and experts, are of particular importance. Today's decision falls short in each of these areas.

[141] Procedural and evidentiary rules should weigh toward facilitating judicial understanding of the issues and thereby reaching the correct result. Yet the Federal Circuit rules today that it will not consider factual findings of the trial court, expressly disavowing such actions by prior panels. The court continues to deny the need to make findings of disputed facts when interpreting claims: "[By] using certain extrinsic evidence that the court finds helpful and rejecting other evidence as unhelpful, and resolving disputes

en route

to pronouncing the meaning of claim language . . . the court is

not

crediting certain evidence over other evidence or making factual evidentiary findings." Maj. Op. at 7 (quoting

Markman

,52 F.3d at 981, 34 USPQ2d at 1331). The court states that it neither accepts the trial judge's findings of fact, nor accepts that there are factual issuesPage 1480in claim interpretation. With these strictures on evidence, witnesses, and findings, it is far from clear how the Federal Circuit proposes to reach the correct claim interpretation.

[142] By continuing the fiction that there are no facts to be found in claim interpretation, we confound rather than ease the litigation process. Without doubt, factual disputes arise and must be resolved in order to interpret the claims. Such facts are normally resolved at trial — yet we now deny ourselves the opportunity even to consider the findings of the trial court.

See

maj. op. at 12 (disavowing the procedure in a Federal Circuit opinion whereby the court recognized the trial court's "`trained ability to evaluate [expert] testimony in relation to the overall structure of the patent' and the trial court's `better position to ascertain whether an expert's proposed definition fully comports with the specification and claims'"). The court today not only rejects the opportunity to give normal appellate deference to the proceedings and findings of trial, but also rejects the opportunity to consider them at all.

[143] In

Markman

the en banc court took the position that in patent cases, unlike any other area of law, a disputed question of the meaning, scope, and usage of terms of technologic art is not a question of fact, or even of law based on underlying fact, but is pure law. However, the Supreme Court has relieved us of adherence to this fiction, by its recognition of the factual component of claim interpretation. Further, the Court's affirmation that claim interpretation "is exclusively within the province of the court,"116 S.Ct. at 1387, 38 USPQ2d at 1463, did not shut out the trial judge along with the jury. In declining to affirm the Federal Circuit's fact/law theory, the Court opened the door for retreat from this artificial construct. I urge us to do so, for experience shows that unforeseen and undesired consequences are flowing from its rigidity. Now that this fact/law rigor is no longer necessary for constitutional combat, let us review these consequences and accept this invitation to advance our procedures.

[144] For example, in

Markman

the Federal Circuit stated that it is not a finding when one side's evidence is accepted and the other side's evidence is rejected.52 F.3d at 981, 23 USPQ2d at 1331. Since accepting one side's evidence and rejecting the other's based on an assessment of validity would be a finding, some other criterion must be the basis for the choice. The court has never stated what this criterion could be, except that accepted evidence should be "helpful," an answer that begs the question.

[145] A fresh view of fact and law would also ameliorate the constraints we have placed on the presentation of extrinsic evidence on the issue of claim interpretation. Patent litigation now often starts with a preliminary hearing to interpret the disputed claim terms, and often produces an early summary judgment, a path perhaps fostered by our foreclosure of the certified question. This preliminary ruling can be dispositive of the dispute, for the scope of the claim often decides whether there can be literal infringement. Thus I add to my concerns the position of the Federal Circuit, here reaffirmed, that extrinsic evidence is of strictly limited availability in claim interpretation. Such evidence should be encouraged, not restrained, if summary disposition is at hand.

[146] The value of extrinsic evidence in claim interpretation is not surprising, because patent documents are written by and for persons in the field of the invention, not for judges. Judges not only need a larger understanding of the science or technology, but we also need help with understanding how the particular terms as used in the patent are viewed by persons in the field of the invention. As Judge Schwarzer observed:

The context in which [issues of science and technology] arise varies widely, but generally they share one characteristic. They challenge the ability of judges and juries to comprehend the issues — and the evidence — and to deal with them in informed and effective ways. As a result, they tend to complicate the litigation, increase expense and delay, and jeopardize the quality of judicial and jury decision making.

[147] Federal Judicial Center,

Reference Manual on Scientific Evidence

1 (1994). The Federal Circuit's ruling that extrinsic evidence must be restricted unless there is a facial ambiguity in the meaning of the claim is an unnecessary restraint on potentially useful evidence.

See Daubert

v. Merrell Dow Pharmaceuticals, Inc.

,Page 1481509 U.S. 579,588(1993) ("`If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert . . . may testify thereto in the form of an opinion or otherwise.'") (quoting Fed.R.Evid.702).

[148] Of course the primary source of information concerning the claimed invention is the patent documents. But such documents are directed to persons knowledgeable in the field; additional evidence and expert testimony as to their meaning should be the rule, not the exception. So-called "extrinsic" evidence — the evidence of expert witnesses and of experimentation, exhibits, demonstrations, and explanation — should be treated like any other evidence, and received and given weight and value as appropriate. Our broad constraint on resort to such evidence is an unnecessary bar to enlightenment. It is also an incursion into the authority of the trial court.

See General Electric Co. v. Joiner

,118 S.Ct. 512,515(1997) (decision of trial court to admit or exclude expert testimony is reviewed on abuse of discretion standard).

[149] The real issue with respect to such evidence is not the threshold question of admissibility, as this court appears to hold, but of weight, upon examination of the evidence and in conjunction with the other evidence. These too are matters for the trial judge, and when the threshold criteria of relevance and reliability are met,

see Daubert

, the evidence should be received and considered as appropriate to its credibility and weight. It follows that the trial court's factual findings with respect to evidence relevant to claim interpretation should be treated, on appeal, like any other finding of the trial court.

[150] Thus it is quite discouraging to observe this en banc ruling wherein the Federal Circuit prohibits itself from considering the findings of fact made by the trial court. The majority opinion disavows this court's prior statement that "[t]he district court's findings of scientific/technological fact were material to the issue of construction of the term." This disavowal deprives the court, and the parties, of the accumulated progress and experience of the trial, including the findings of the trial judge, and leaves us on appeal with an expurgated record and generally inferior basis of decision. Recognizing that our appellate role is to decide whether the claims were correctly interpreted in light of all of the evidence, it is mysterious why we choose to self-censor what we will consider on appeal. It is equally obscure why this court would prohibit itself from relying on a trial court's findings, or from choosing between disputed expert positions. I strongly disagree with the majority's view of the role of extrinsic evidence, at trial and as considered on appeal.

[151] In contrast, a return to the traditional trial/appellate relationship would achieve several important results. It would rationalize the admissibility of relevant extrinsic evidence, appellate deference would be restored instead of disavowed, and appellate review would be in accordance with the rules. The processes of both trial and appeal would benefit. This is particularly important because the evidence involved in claim interpretation, whether intrinsic or extrinsic, is often scientific or technologic. The evidence of what the invention is, how it works, what the technical words meant to persons in the field at some past time, can be of extreme complexity. When there is a dispute as to what a term of technical art or usage means or encompasses, such evidence is relevant and often is indispensable. Why would our court foreclose, or place obstacles in the path of, adducing and considering such evidence?

[152] Surely the better view is to encourage judicial access to scientific evidence and findings based thereon. The ultimate beneficiary would be the parties, for the courts would be less restricted in the search for the correct and just result in patent cases. Thus I must, respectfully, dissent from the court's rulings on these issues.

Chief Judge Haldane Robert Mayer assumed the position of Chief Judge on December 25, 1997. ↩
Senior Circuit Judge Glenn L. Archer, Jr. vacated the position of Chief Judge on December 24, 1997. ↩
The actual patent claim is not written in paragraph form as shown here; we have added the breaks for ease of reference to the claim's limitations. ↩
Both FAStar and FAS Technologies filed an answer to Cybor's complaint. FAStar alone originally filed the counterclaim, but FAS Technologies was joined as a counterclaimant after the jury trial on liability was completed. ↩
It is difficult to reconcile the language and reasoning in this court's recent opinion in
Fromson v. Anitec Printing Plates, Inc.
,132 F.3d 1437, 45 USPQ2d 1269 (Fed. Cir. 1997), with
Markman I,
although the opinion purports to do so. As we stated in
Markman I,
"extraneous evidence [such as the expert testimony in
Fromson
] is to be used for the court's understanding of the patent" and in doing so, the court "is
not
crediting certain evidence over other evidence or making factual evidentiary findings."
Markman I
,52 F.3d at 981, 34 USPQ2d at 1331 (emphasis in original). Rather, we considered such evidence to be an aid to the court in coming to a correct conclusion as to the true meaning of the language employed in the patent.
See id.
at 980, 34 USPQ2d at 1330. The Supreme Court in effect confirmed this when it stated that the credibility determinations among experts "will be subsumed within the necessarily sophisticated analysis of the whole document."
Markman II
,116 S.Ct. at 1395. In
Fromson
, the district court "relied primarily on the '754 specification which describes Fromson's first anodization step as producing [a] porous oxide" barrier.
Fromson
,132 F.3d at 1442, 45 USPQ2d at 1272. Although the extrinsic evidence — expert testimony, prior art, and scientific tests — confirmed the district court's claim construction, it was directed primarily to whether Anitec's thin, nonporous oxide layer infringed the claims. To this extent, the holding in
Fromson
affirming the district court's claim interpretation follows
Markman I
.
See Bell Howell Document Management v. Altek Sys.
,132 F.3d 701,705-06, 45 USPQ2d 1034, 1038 (Fed. Cir. 1997);
Vitronics

Corp. v. Conceptronic, Inc.
,90 F.3d 1576,1584, 39 USPQ2d 1573, 1578 (Fed. Cir. 1996). ↩
If this were so, surely the Supreme Court would have discussed whether subsidiary or underlying fact questions should be decided by the judge or the jury. ↩
Because Cybor's claim construction arguments relate to the narrowing of claim scope required by prosecution history, we need not consider whether equivalence under § 112, ¶ 6 is a question of law or fact.
See Markman I
,52 F.3d at 977n. 8, 34 USPQ2d at 1327 n. 8. Here, the question of equivalence was given to the jury and Cybor does not challenge the equivalence of its accused device if prosecution history does not narrow the scope of the claims as Cybor argues. One concurring opinion also recognizes that Cybor's claim construction arguments relate solely to whether the prosecution history requires the exclusion of the external "reservoir structures like Cybor's from consideration as an equivalent under § 112(6)."
See
Opinion Concurring in the Judgment of Chief Judge Mayer,
infra
, at 13-14. ↩
Cybor contends that the jury was not adequately instructed on the meaning of the claims. We note, however, that this case was tried before
Markman I
and that, while a fuller instruction to the jury on the meaning of the claim might be desirable, the instructions were not erroneous. Moreover, the district court's denial of the motion for reconsideration approved the additional, presumptive construction of the claims by the jury. ↩
One concurring opinion suggests that this court cannot affirm the decision below under a
de novo
standard of review, asserting that the basis for the jury's decision is unclear. We disagree that the jury could have had in mind the several variations posited by the concurrence. It is patently impossible for Cybor's pump, without a reservoir, to perform the functions called for by the patent. Thus, the jury had to consider the combination of Cybor's pump and the external, attached reservoir as being a "pumping means" equivalent to the structure disclosed in the patent, which consisted of a pump with an internal reservoir. ↩
Rather than bluntly force the square peg of claim construction into the round hole of fact or law, the Court described the questions presented by claim construction in more chary terms: "[b]ut the
sounder
course,
when available
, is to classify a mongrel practice," "no clear answers," "
in theory there could be a case
," "
leaves us doubtful
," "
[i]n

the main
," "
[w]e accordingly think
there is sufficient reason
to treat
construction of terms of art like many other responsibilities that we ceded to a judge," "independent reason
to allocate
," "
treating
interpretive issues
as
purely legal will promote . . . ."
Markman
,116 S.Ct. 1390-96(emphasis added). Even a cursory reading of that opinion indicates that the Court meant to determine who should interpret the claims, without mandating a standard of appellate review to be used under all circumstances. ↩
Although having a jury make a legal determination of the effect of statements made during prosecution of the patent is error, alone this error was harmless because to find infringement, the jury must have arrived at the same legal conclusion that we did on appeal: that the prosecution history does not exclude Cybor's external reservoir from the jury's consideration of equivalents under paragraph 112(6). ↩
Findings of fact are presumed where they would be necessary to support a jury's verdict.
See Perkins-Elmer Corp. v. Computervision

Corp.
,732 F.2d 888,893, 221 USPQ 669, 673 (Fed. Cir. 1984) ("To facilitate review on a motion for [judgment as a matter of law] and on appeal, it is preferred that a jury be provided with special interrogatories designed to reveal more clearly the findings it made. Absent such interrogatories, the law presumes the existence of findings necessary to support the verdict the jury reached.");
see also Railroad

Dynamics, Inc. v. A. Stucki Co.
,727 F.2d 1506,1516, 220 USPQ 929, 939 (Fed. Cir. 1984). ↩
In fact, the district court submitted this case to a jury
before
this court decided
Markman v. Westview Instruments, Inc.
,52 F.3d 967,979, 34 USPQ2d 1321, 1329 (Fed. Cir. 1995) (
Markman I
). Thus, the district court's jury instructions only partially construed the claims, and the
en

banc
opinion relies, as it must, upon what it presumes must have been the jury's claim construction. Nor did the district court deliberately accept and rely upon expert testimony to understand and interpret the claim terms, a central issue in
Markman I
. Heedless of these problems, this court has selected this case for
en banc
review.
Fromson v. Anitec

Printing Plates, Inc.
,132 F.3d 1437, 45 USPQ2d 1269 (Fed. Cir. 1997), may have been a more suitable choice for meaningful
en banc
consideration of the issue of appellate deference in claim construction. The district court decided
Fromson
by applying the
Markman I
regime. The
Fromson
district court also relied upon extrinsic evidence and findings of scientific/technologic fact to interpret the meaning of claim terms to one of ordinary skill in the art at the time of the invention (over twenty years ago). Thus, the facts of
Fromson
might have better illustrated how different standards of review can direct the outcome on appeal. ↩
The following is an incomplete list of procedural deviations required by
Markman I
:
1. Multiple trials, problem I: If hearings are necessary to interpret complex claims, the trial court must set aside time in its crowded docket for one proceeding to interpret claims and a second (potentially with a jury) to determine infringement and other issues.

2. Claim interpretation, problem I: Fearing that it may not receive the opportunity to supplement expert reports or reopen discovery after the judge's interpretation, a party often argues alternative claim construction theories from the outset of litigation. This extends the time and expense of the claim interpretation proceedings.

3. Bias toward summary judgments: In practical terms,
Markman I
directs the proceedings toward summary judgment on the central issue of the litigation at a potentially premature stage of issue development. Prematurely addressing issues, even at the appellate level, can result in expensive repetition of effort.
See CVI/Beta Ventures, Inc.

v. Tura LP
,112 F.3d 1146,1157-58,1160n. 7, 42 USPQ2d 1577, 1585, 1587 n. 7 (Fed. Cir. 1997) (finding error in a claim construction that had been affirmed in an earlier appeal),
cert. denied
,118 S.Ct. 1039(1998).

4. Claim interpretation, problem II: As soon as the trial court issues a claim interpretation, both sides often seek to shift their original claim interpretations to accommodate the judge's views. Thus, the parties seek to revise expert reports or reopen discovery to account for the judge's interpretation. This maneuvering leads to procedural battles over surprise and motions for additional time to prepare for trial.
See Loral Fairchild Corp. v. Victor Co.
,906 F. Supp. 798(E.D.N.Y. 1995) (interpreting claims);
Loral

Fairchild Corp. v. Victor Co.
,911 F. Supp. 76,80-81(E.D.N.Y. 1996) (preventing plaintiff from changing theory of infringement in response to claim interpretation).
5. The new evidence dilemma: As a result of the new and perhaps somewhat unexpected interpretation, the parties scramble to create and acquire new evidence for their infringement arguments.

6. The learning curve problem: Like all human endeavors, claim interpretation is a learning process. The trial judge makes every effort to state the precise scope of the claims at the close of the initial proceeding, but often, with the additional learning during the infringement trial, realizes that the initial interpretation was too broad or too narrow in some respects. The judge then faces the dilemma of changing the rules in the middle of the game.

7. The judge as a trial issue: With the judge's claim interpretation central to the issues of infringement, trial counsel will try to exploit the judge's stature with the jury to show that the court is on their side.

8. Multiple trials, problem II: In the words of United States District Court Judge Roderick McKelvie: "[I]n spite of a trial judge's ruling on the meaning of disputed words in a claim, should a three-judge panel of the Federal Circuit disagree, the entire case could be remanded for retrial on [a] different [claim interpretation]."
Elf Atochem North

Am., Inc. v. Libbey-Owens-Ford Co.,
894 F. Supp. 844,857, 37 USPQ2d 1065, 1075 (D. Del. 1995).

Trial judges can often address each of the above with careful case management, but at the cost of expending scarce trial court resources. ↩
Three variables affect the settlement calculus of each party to litigation:p,the probability of the plaintiff obtaining damages;J, the expected value of a judgment for the plaintiff; andc, the cost of litigation.
See
Richard A. Posner,
The Federal Courts: Challenge and

Reform
89-94 (1996). IfpxJ(pJ)exceedsc, then plaintiff will sue. The plaintiff values the case atpJ—c. If the defendant agrees on the values assigned to the variables, the suit will cost himpJ+c. This rough model poses an interesting question. Because the costs of litigation invariably exceed the costs of settlement, why do not all cases settle? Chief Judge Posner answers: "[U]ncertainty as to outcome is the key to the settlement rate . . . ."
Id.
at 90. This uncertainty leads each party to overestimate its chance of prevailing. Accordingly, each party will assign different values to the variables, most notablyp, thereby diminishing the likelihood of settlement. ↩
This figure is based on a survey of every patent decision rendered by the Court of Appeals for the Federal Circuit between 5 April 1995 (the date
Markman I
was decided) and 24 November 1997. A total of 246 patent cases, originating in the Board of Patent Appeals and Interferences (BPAI), the district courts, and the Court of Federal Claims, were evaluated. Of the 246 cases, 141 cases expressly reviewed claim construction issues. Among these 141 decisions, this court reversed, in whole or in part, 54 or 38.3% of all claim constructions. With respect to the district court and Court of Federal Claims cases, the rate of reversal of claim constructions is 47 out of 126 or 37.3%. ↩
These necessary strictures contribute to the Federal Circuit's perception of claim construction. Pressured by these necessary rules, parties before the Federal Circuit strive mightily to reduce their cases to a few issues controlled by a few passages from the specification or the prosecution history. For these reasons, the appeal process does not present a fair picture of the complex task of untangling the knot of legal and factual issues presented for trial. A seemingly simple issue of claim construction on appeal takes on an entirely different complexion in its proper context as one tiny facet of a massive corpus of litigation. ↩
In 1993 the Carnegie Commission on Science, Technology, and Government wrote:
The courts' ability to handle complex science-rich cases has recently been called into question, with widespread allegations that the judicial system is increasingly unable to manage and adjudicate science and technology issues.

Report, March 1993,p. 11.Page 1344 ↩