Hilton Davis Chemical Co. v. Warner-Jenkinson Company, Inc.

PLAGER, Circuit Judge, with whom Chief Judge ARCHER and Circuit Judges RICH and LOURIE join,

dissenting.

1.

The court today tells us some important things about the doctrine of equivalents. We are told that application of the doctrine turns on one primary test: the substantiality of the differences between the claimed and accused products.1 The function-way-result test, so often recited since Graver Tank as the controlling test, is not “the” test. Rather, in assessing substantiality, other objective indi-cia may be considered, such as the known interchangeability of the accused and claimed elements by persons reasonably skilled in the art; whether there is evidence of intentional copying; and whether there is evidence of an attempt to design around the patented matter.

Function-way-result still plays a part, although exactly what that part is may seem obscure to some. That test, it is explained, arose in days of relatively simple mechanical technology. More sophisticated and innovative products may require more sophisticated analysis and thus different evidence, al*1537though it would appear that this depends as much on the lawyer and the judge as on the product: the trial judge will decide whether the additional evidence, if any, offered by the patentee is ‘relevant’ to the case. Straight function-way-result turned out to be sufficient for the ultrafiltration through osmosis technology involved in this case.

The court also tells us that the burden is on the patentee to produce the necessary evidence of insubstantiality, and that these evidentiary questions are questions of fact.

Taken singly, most of these propositions are familiar. Packaged as they are, they may come as a revelation to many in the bar, as they no doubt do to the parties in this case. The court’s statement that “[tjhis case presents an opportunity to restate — not to revise — the test for infringement under the doctrine of equivalents” is difficult to take literally. What the court has given us is a recipe in which familiar ingredients are to be mixed in a different way, to produce what must be presumed to be a better product. But there is no reason to suppose that the new product will in fact be better. The mixing is still to be done in the dark, by the multiple hands of a jury under minimal instruction. When that product, an announced “yes, it infringes” or “no, it does not” arrives at this court, we will remain as blinded as we are now in our ability to pierce the doctrinal veil.

If we are to know where we are going with the doctrine of equivalents, we must know whence it came. The court denies that the doctrine has its roots in a court’s traditional equity powers, but provides no substitute explanation for its origin. As a result, we are left with two major problems that are not satisfactorily resolved: what are the controlling bounds of the doctrine, and what are the proper respective roles of judge and jury.

2.

As a preliminary matter, it may be asked why the court needs to undertake this inquiry into the doctrine of equivalents at all. Is something broke that needs fixing? The short answer is yes.2 One problem is that, whatever role the doctrine of equivalents may have played in earlier times — and while that is not immaterial it is largely irrelevant — today the doctrine is regularly used by patentees to seek greater coverage for their patents than the patent statute grants. Their demands are presented to a jury which is told to decide the issue based on a formulaic chant — function, way, result — which, as Judge Lourie so aptly describes in his dissent,’ provides little in the way of guidance, and in some cases may be of no persuasive significance at all.

A related problem is that our current case law imposes no substantial constraints on the availability of the doctrine. Any patentee may invoke it as a second prong to an infringement' suit, in addition to the statutory cause of literal infringement. Prior to 1870, the date when inventors were first statutorily required to particularly and distinctly claim their invention, see Act of July 8, 1870, § 26, 16 Stat. 201, the scope of protection turned on the embodiments disclosed in the specification. Courts read these specifications broadly, to include equivalents, in order to give the patentee the full scope of the invention. Over the past hundred or so years, that practice has given way to a focus on precisely what the inventor claims as the invention. The specification remains important, not as the definition of the invention, but as a description of it and as an aid in interpreting the language of the claims.

By today’s opinion, the majority essentially blesses the continued unfettered use of the doctrine of equivalents, at the discretion of a jury, noting that in some eases at least the ritual chant will be quite sufficient justification for a rewriting of the claimed hmitations. This ignores the fact that, after 1870, claims, not their equivalents,-are the determinants of the scope of protection granted by the pat*1538ent. Claiming practice today serves a purpose which the earlier practice did not, namely providing competitors with notice of the precise invention that they may not make, use, or sell.

Another problem with the doctrine is that appellate review of many of these doctrine of equivalents cases is largely pro forma. Federal district judges, perhaps understandably, by and large make little pretense of liking these patent infringement cases, and' are quite content to give them, and all the issues in them, to juries to decide. The cases typically come to us on appeal with nothing more than a general verdict finding infringement. There is no explanation by the jury of the rationale behind their verdict, if any exists. This case is a good example.3

In our review we must assume.that the jury understood the technology, understood the law of patents and the policies that underlie it, understood the function, way, and result of the matter, and arrived at a considered decision. It is enough to sustain a jury verdict of infringement By equivalents if the trial court’s instructions are without prejudicial error (oftentimes this translates into the less said the better), and if there is any substantial evidence in the record which the hypothetical reasonable juror could have be: lieved, and so believing, arrived at the verdict. A plaintiff must have a virtually impossible case, or incompetent counsel, to fail to have something in the record which can be argued is substantial enough. In short, though the opinions we write, with their routine recitations of ora’ standard of review followed by the inevitable citations, may tend to obscure the reality, the reality is that the doctrine of equivalents is a virtually uncontrolled and unreviewable license to juries to find infringement if they so choose. And this is done largely without regard to and independent of the express limitations of the patent claims which may have brought about their allowance by the Patent and Trademark Office (PTO) in the first place. See Perkin-Elmer Corp. v. Westinghouse Elec. Corp., 822 F.2d 1528, 1532-33, 3 USPQ2d 1321, 1324-25 (Fed.Cir.1987) (“One must start with the claim, and, though a ‘non-pioneer’ invention may be entitled to some range of equivalents, a court may not, under the guise of applying the doctrine of equivalents, erase a plethora of meaningful structural and functional limitations of the claim on which the public is entitled to rely in avoiding infringement. ... The statement should not be interpreted as sanctioning the treatment of claim limitations as insignificant or immaterial in determining infringement. ‘It is ... well settled that each element of a claim is material and essential, and that in order for a court to find infringement, the plaintiff must show the presence of every element or its substantial equivalent in the accused device.’ ”) (quoting Lemelson v. United States, 752 F.2d 1538, 1551, 224 USPQ 526, 533 (Fed.Cir.1985) (footnote omitted)). The obligation on the inventor to particularly point out and distinctly claim what the applicant regards as his invention, discussed below, the legitimate practice of competitive designing around, and the opportunities given to the public to benefit from the mandatory disclosures required of the patentee, all are thrown into disarray by this unpredictable aspect of current patent litigation.

Responsibility for these problems and for the unsatisfactory situation they create lies with the judges. It is the result of how we have interpreted Supreme Court opinions on *1539the matter, and how, largely by default, we have permitted the practice of patent litigation to take the shape it now is in. It is our responsibility to address the situation, and to take effective corrective action. We and the Supreme Court are the only two appellate courts with authority to do this. It is regrettable that, in today’s opinion, the majority abdicates this responsibility, leaving to the Supreme Court the obligation of attending to the problem if it is to be attended to at all.

3.

Turning, then, to the question of the doctrine’s roots, and thus its boundaries, our examination begins, as it must, with the statute that creates and defines the patent right, 35 U.S.C. §§ 1-376.4 The application for a patent must include a specification which “shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.” 35 U.S.C. §§ 111, 112 ¶2. It is the claims that define the metes and bounds of the right to exclude others from making, using or selling the invention that is granted by the patent. Zenith Lab., Inc. v. Bristol-Myers Squibb Co., 19 F.3d 1418, 1424, 30 USPQ2d 1285, 1290 (Fed.Cir.), cert. denied, — U.S. -, 115 S.Ct. 500, 130 L.Ed.2d 409 (1994).

This has been true for a long time. In the now century-old case of Keystone Bridge Co. v. Phoenix Iron Co., 95 U.S. 274, 278, 24 L.Ed. 344 (1877), the Supreme Court said:

Since the act of 1836, the patent laws require that an applicant for a patent ... “shall particularly specify and point out the part, improvement, or combination which he claims as his own invention or discovery.” This provision was inserted in the law for the purpose of relieving the courts from the duty of ascertaining the exact invention of the patentee by inference and conjecture, derived from a laborious examination of previous inventions, and a comparison thereof with that claimed by him. This duty is now cast upon the Patent Office. There his claim is, or is supposed to be, examined, scrutinized, limited, and made to conform to what he is entitled to.
If the office refuses to allow him all that he asks, he has an appeal. But the courts have no right to enlarge a patent beyond the scope of its claim as allowed by the Patent Office.... When the terms of a claim in the patent are clear and distinct (as they always should be), the patentee, in a suit brought upon the patent, is bound by it. Merrill v. Yeomans, 94 U.S. 568, 24 L.Ed. 235. He can claim nothing beyond it.

Judge Rich, explaining current American law to European judges, described it this way:

The U.S. is strictly an examination country and the main purpose of the examination, to which every application is subjected, is to try to make sure that what each claim defines is patentable. To coin a phrase, the name of the game is the claim.... the function of claims is to enable everyone to know, without going through a lawsuit, what infringes the patent and what does not.

Giles Rich, The Extent of the Protection and Interpretation of Claims — American Perspectives, 21 Int’l Rev. Indus. Prop. & Copyright L. 497, 499, 501 (1990).

Nothing in the statute talks about extending the patent right to the equivalents of what is claimed, or to any other version of the invention beyond that described and claimed in the specification. “The specification shall contain a written description of the invention ...,” 35 U.S.C. § 112 ¶ 1, and the patent covers that which is “distinctly claim[ed].” 35 U.S.C. § 112 ¶2. If Congress wanted to provide for equivalents to what is claimed, it knew how to do it. In a means plus function claim, for example, the structure, material, or acts that support the claim are to be construed to cover the corresponding structure, material, or acts described in the specification “and equivalents thereof.” 35 U.S.C. § 112 ¶ 6. One looks in vain for similar language qualifying the claims that are at the heart of the patent right.

*1540The doctrine of equivalents is a judge-made exception to these statutory mandates. Congress is free to make law without necessarily explaining the reasons for its rules, but that is not a power with which courts are endowed. Nor are courts empowered to rewrite legislation. They may not add new requirements to a comprehensive statutory scheme when there is an absence of even a facially-plausible provision alleged to be subject to interpretation.

Although courts are not empowered to rewrite or add to legislation, the English Chancellor took upon himself in an appropriate case, and American courts of equity have followed suit, the role of protecting legal rights, including rights created by statute, from abuse by a too-narrow application of the law causing an unjust result. See generally Fleming James, JR., Civil ProceduRE 8-16 (1965); F.W. Maitland, Equity, 1-22 (1929). This power, however, was carefully cabined. There has to be a showing of truly special circumstances, of a situation in which a wrong would be committed by a mindless application of law. In such a situation, the court of equity does not grant new or unlimited rights to a claimant, but rather protects the claimant’s established legal rights by providing a uniquely equitable remedy.

The legal rights established by a patent are defined by the claims. Competitors and other members of the public are entitled to rely on the scope of the claims set out in a patent, as the statute requires, and to design around the patentee’s statutorily-protected rights. Hoganas AB v. Dresser Indus., Inc., 9 F.3d 948, 951, 28 USPQ2d 1936, 1939 (Fed.Cir.1993) (“It would not be appropriate for us now to interpret the claim differently just to cure a drafting error.... That would unduly interfere with the function of claims in putting competitors on notice of the scope of the claimed invention.”). In the famous nose of wax analogy, the Supreme Court in White v. Dunbar, 119 U.S. 47, 51-52, 7 S.Ct. 72, 74-75, 30 L.Ed. 303 (1886), said:

Some persons seem to suppose that a claim in a patent is like a nose of wax, which may be turned and twisted in any direction, by merely referring to the specification, so as to make it include something more than, or something different from, what its words express_ The claim is a statutory requirement, prescribed for the very purpose of making the patentee define precisely what his invention is; and it is unjust to the public, as well as an evasion of the law, to construe it in a manner different from the plain import of its terms. This has been so often expressed in the opinions of this court that it is unnecessary to pursue the subject further.

In most cases, if the claims do not literally apply to the allegedly infringing product, that should end the matter. But, when there is a wrong for which there is no adequate remedy at law, equity courts have traditionally gone beyond the law to impose a just and equitable result. Thus in those special cases in which the competitor’s product is literally different but the difference is so insubstantial as to constitute a ‘fraud on the patent,’ a court in the exercise of its extraordinary equity power may extend the remedy of infringement in order to protect the rights of the patentee granted by law.

The power of courts of equity to deviate from the strict requirements of law is not without limits. Even in the interests of justice, courts of equity are not free to make unfettered and unreviewable decisions. They are as much subject to rules of law as are the law courts. Thomas Jefferson, arguing against giving federal courts broad equitable powers, said, “Relieve the judges from the rigour of text law, and permit them, with pretorian discretion, to wander into it’s equity, and the whole legal system becomes in-certain.” 9 Papers of Thomas Jefferson 71 (J. Boyd ed. 1954). The supporters of a strong federal judiciary recognized the merits of the argument. In response to such concerns, Alexander Hamilton wrote, “To avoid an arbitrary discretion in the courts, it is indispensable that they should be bound down by strict rules and precedents which serve to define and point out their duty in every particular case that comes before them.” The Federalist No. 78, at 529 (J. Cooke ed. 1961). This argument echoed the long-running fight between the common law courts of England and the emerging courts *1541of equity.5 Blackstone wrote in his famous commentaries on the English law: “[I]f a court of equity were still at sea, and floated upon the occasional opinion which the judge who happened to preside might entertain of conscience in every particular case, the inconvenience that would arise from this uncertainty, would be a worse evil than any hardship that could follow from rules too strict and inflexible.” 3 W. Blackstone, Commentaries 440 (1786).

The need for clear and reviewable boundaries is as applicable to patent law as to other areas of law, lest the power inherent in the doctrine of equivalents destroy the reliance on the scope of claims to which every competitor is entitled. “The inventor must ‘inform the public during the life of the patent of the limits of the monopoly asserted, so that it may be known which features may be safely used or manufactured without a license and which may not.’ ” United Carbon Co. v. Binney & Smith Co., 317 U.S. 228, 232, 63 S.Ct. 165, 168, 87 L.Ed. 232 (1942) (quoting General Elec. Co. v. Wabash Corp., 304 U.S. 364, 369, 58 S.Ct. 899, 902, 82 L.Ed. 1402 (1938)).

The majority opinion correctly recognizes the notion of protecting legal rights by extending a flexible remedy when the difference between the protected rights of the patentee and the product of the infringer is insubstantial. But the majority fails to acknowledge — indeed, denies — the equitable source of that remedy. The court states that the doctrine has “no equitable or subjective component,” slip op. at 1522-23, but that confuses the jurisprudential basis of the power with the evidentiary reasons for its exercise. The court further states that the question of infringement, whether literal or by equivalents, is a question of fact, a proposition that no one challenges. But the court follows that statement with the conclusion that, since infringement by equivalents is a question of fact it must therefore be a question for a jury, as if equity courts in the course of their work never decide factual issues.

The court cites cases, such as Coupe v. Royer, an 1895 Supreme Court decision, arguing that it proves that “the question of infringement under the doctrine presented a question requiring trial to the jury.” Slip op. at 1525. In addition to being somewhat antiquarian (the complaint was brought under the old form of action called trespass on the case), the opinion makes no such holding. The issue in the case was whether the paten-tee’s machine for treating raw hides was infringed by the defendant’s machine. There is nothing to indicate that the case involved anything other than a question of literal infringement as it was understood then, and the matter was tried to a jury. The trial judge instructed the jury at some length as to the meaning of the claim language, giving the language a broad construction. The Supreme Court found the judge’s construction over-broad and erroneous, stating that “such construction must be in conformity with the self-imposed limitations which are contained in the claims,” and cited to Keystone Bridge. On the relative roles of judge and jury, the court quoted from Robinson on Patents: “Where the defense denies that the invention used by the defendant is identical with that included in the plaintiffs patent, the court defines the patented invention as indicated by the language of the claims; the jury judges whether the invention so defined covers the art or article employed by the defendant.” 155 U.S. at 579, 15 S.Ct. at 205. The judgment was reversed for a new trial under proper instructions.

As Coupe v. Royer and the other cases of that era and since establish, the law provides the patentee with a remedy for infringement of the express terms of the patentee’s claims. The patentee, subject to the approval of the Commissioner of Patents and Trademarks, writes those claims, and may claim what he invents. His failure to claim what he might, or as clearly as he might, is a drafting problem, not a judicial one. This does not make light of the difficulty inherent in claim drafting, but merely identifies where the problem and its solution lie. The solution to the problem of inadequate or incomplete claim drafting is not arbitrary after-the-fact ‘interpretation’ under the guise of ‘equivalents,’ whether by judge or jury, that goes beyond *1542anything in the claims themselves. See Hoganas, 9 F.3d at 951, 28 USPQ2d at 1939.

In this case, the patentee added a claim limitation of “a pH from approximately 6.0 to 9.0” in order to distinguish the Booth patent, which disclosed an ultrafiltration process using a higher pH. Why the inventors specified a low end of 6.0 is not discussed in the patent. It appears, however, that the designated lower limit was also intentional; Dr. Cook' testified at trial that though the process would work to separate the dye from the impurities at pH-values as low as 2.0, a solútion with a pH below 6.0 would cause “tremendous foaming problems in the plant.” Each whole number below 6.0 represents a difference of 10 times the amount (the pH scale is logarithmic). Yet, under the function-way-result test approved here, a jury might well have found that a pH of 2 or 3 was equally violative under the doctrine. Surely the boundaries of a claim cannot be left that fluid and still have claims that perform their assigned mission. Courts, either at the trial or appellate level, must be prepared to police the application of this extraordinary power in order to protect the public’s interest.

4,

The majority’s failure — or refusal — to acknowledge the uniquely equitable nature of the doctrine of equivalents with its built-in constraints leads to a basic error in the opinion, and that is the failure to effectively deal with the respective roles of judge 'and jury. The majority simply continues the status quo, which, if the plaintiff patentee chooses and the trial judge does not disagree, allows by default both literal infringement and infringement under the doctrine of equivalents to go to the jury.6 For the reasons discussed earlier, that is operationally unsatisfactory and jurisprudentially unjustified, and in our opinion clearly contrary to the public interest.

The majority offers no persuasive explanation for its position. As it must, the majority recognizes that cases from this court and the Supreme Court often speak of the equitable nature of the relief afforded by the doctrine of equivalents. Slip op. at 1521, and n. 2. Then by way of ipse dixit, the majority opines that “neither the Supreme Court nor this court has invoked equity in the technical sense of a set of principles originating in England to compensate for the historically harsh rules of common law.” Slip op. at 1521. The opinion makes the rather obvious point that in Graver Tank, the Supreme Court did not discuss clean hands, the abuse of discretion standard of review, balancing of equities, or any of a myriad of other issues that were not before it. All of which goes to establish a point with which there is no disagreement: the issue dealt with today is one that has not been directly confronted before now, either by this court or by the Supreme Court. As Judge Lourie correctly points out in his dissent, “the [Supreme] Court has not ruled in modern times, under our current practice of relying on statutory claims, as to whether the question of the applicability of the doctrine, with all the factors it outlined, must be tried to a jury when properly requested.” Slip op. at 1521.

Indeed, it is easy to point to cases, old and new, in which, when a jury was impanelled, the function-way-result issue was given willy-nilly to the jury along with the issue of literal infringement. It is understandable that a trial judge, who gets one patent case every few years to try, would be comfortable doing this. The fact that defense counsel have not challenged the practice tells us little, other perhaps than that conventional thinking is easier than any other kind, or that counsel for today’s patent infringer will, on the morrow, represent a patentee plaintiff, so that *1543today’s jury decision adverse to the infringer may be tomorrow’s big win for patentee’s counsel.

Nor does the statement by the Court in Graver Tank, that “[a] finding of equivalence is a determination of fact,” tell us who decides that question in a jury trial. The fact-law dichotomy discussed in Graver Tank, a non-jury ease, was related to the question of the Supreme Court’s standard of review when reviewing a judgment of a trial court following a bench trial. The Court had no occasion to discuss the difference between law and equity, and the respective roles of judge and jury.

To label something a fact issue tells us little about who should decide it. In traditional equitable matters — the rights of beneficiaries under trusts, mistake and fraud in contract disputes, domestic relations, to name just a few — questions of fact are regularly decided by judges. Just as matters of ‘fact’ may be exclusively for the judge, and not for a jury, when the issue is claim interpretation, an issue we have only recently declared uniquely the responsibility of judges, Markman v. Westview Instruments, Inc., 52 F.3d 967, 34 USPQ2d 1321 (Fed.Cir.1995) (en banc), so too matters of ‘fact’ belong to the court when the court exercises its equitable powers in applying the doctrine of equivalents. Cf. Paragon Podiatry Lab., Inc. v. KLM Labs., Inc., 984 F.2d 1182, 1190, 25 USPQ2d 1561, 1568 (Fed.Cir.1993) (per curiam) (“A patentee has no right to a jury trial respecting the factual element of culpable intent as part of the defense of inequitable conduct.”).

Absent some special statutory grant, juries do not exercise equitable powers. There is no issue of a right to a trial by jury under the Seventh Amendment; the court does not suggest that that is the source of the jury’s role. By virtue of its unique place in our legal system, and by long-standing custom and tradition, equity powers are exercisable only by judges. The authority to exercise the unique remedy which is the doctrine of equivalents lies exclusively in courts of equity.7

5.

There are several ways to address the anomalous situation of having had juries involved previously in the application of the doctrine of equivalents. We might acknowledge the existence of the past practice of giving the issue of the doctrine of equivalents to juries; declare that .practice to be antithetical to the jurisprudential roots of the doctrine; and end the practice. As a followup, we could give useful guidance to trial judges on how to assess when a situation called for the special imposition of equity into the otherwise statutorily-defined infringement context. This guidance necessarily would emphasize the importance of keeping such matters as copying, independent discovery, and wrongful intent conceptually separate and distinct. Further experience with determining when and in what circumstances the doctrine is appropriately applied would no doubt refine and extend our understanding of these matters.

This would be a bold and clean solution to the matter. Though bold, it would not be radical, its roots being squarely in the great traditions of our courts going back centuries to the.office of the King’s Chancellor. It would overturn no established law, and would clarify much confusion emanating from the old cases. And it cannot be denied that it would make a major contribution to bringing rationality to this area of patent law.

A second though less bold alternative might be to share the responsibility for the doctrine between judge and jury. Trial judges would be instructed that it is their responsibility to determine when the differences between the patent claims and the allegedly infringing product are so insubstantial, and the circumstances so sufficiently special, as to warrant making the remedy *1544afforded by the dbctrine of equivalents available to a patentee. This determination would be independent of the question of whether the doctrine entitles the patentee to relief. That latter question, and the actual application of the doctrine using the function-way-result formula, would be left to the jury. Again, guidance could be given to trial judges on determining when those circumstances exist. This approach to the problem of judge and jury would have the effect of acknowledging the equitable basis for the doctrine, while preserving the historical practice of giving the function-way-result decision to the jury.

Under this alternative, the trial judge could make the determination at the beginning of the trial process, for example in response to a motion for partial summary judgment regarding the patentee’s count alleging infringement under the doctrine of equivalents. Or, in an appropriate case, the trial judge could await presentation of the evidence so as to better understand the extent of the differences between the accused product and the claims, and then rule in response to a motion for judgment on that count. In either event, this court could require that on appeal there would be detailed findings of fact and conclusions of law to review, regardless of what the jury did under the function-way-result test.

This second alternative, an amalgam of two quite diverse approaches to the issue, is not without its problems. In particular, the in-substantiality assessment made by the judge overlaps in considérable degree with the function-way-result analysis to be applied by the jury. Nevertheless, this alternative, though not as bold and not as clean as the first, still would have advanced the matter, and placed in the trial courts, and in this court on review, proper responsibility to police the availability of the extraordinary equitable relief granted under the doctrine, while preserving the role that has been accorded to the jury.

Regrettably, the court today neither cabins the availability of the doctrine, nor places responsibility for determining that availability where it belongs, in the judges who created the doctrine. The court’s opinion makes at most a marginal contribution to our understanding of the notion of insubstantiality as an element in analysis. It leaves unchanged the present unsatisfactory decision process, and makes little effort to effectively incorporate its newly-articulated standard into the fabric of the law. At a minimum, it might have been expected that the court would express its disapproval of general jury verdicts of infringement under the doctrine, and insist that juries at least be required to articulate, through special interrogatories, the facts and conclusions that support these verdicts.8

The importance of recognizing the equitable basis of the doctrine is not simply that of historical accuracy. The public interest is at issue. When the question is enforcing rights that are specifically defined by statute, it can be assumed that the legislative enactment incorporates the proper balance between private and public, and enforcement of the declared private right is in the public interest. When the question is one of equitable relief, the public interest is a factor that must be weighed in the balance in each case. “As always when federal courts contemplate equitable relief, our holding must also take account of the public interest.” U.S. Bancorp Mortgage Co. v. Bonner Mall Partnership, -U.S. -, -, 115 S.Ct. 386, 392, 130 L.Ed.2d 233 (1994).

The matter before the court in these equivalents cases is not only the claims of the parties against each other, but the interest of *1545the public in protecting reliance by competitors on the public record, and in ensuring that patent rights are given their due and no more. Juries may serve to resolve rights conflicts between private litigants; judges bear the responsibility of ensuring that, when the claims being urged are not based on clearly defined rights, the balance that is struck is struck in the public interest.

This court should accept the duty imposed on us by Congress, as the exclusive appellate forum short of the Supreme Court, to bring a consistent and rationalized practice to the doctrine of equivalents. If we had done that, we would probably have found it appropriate to vacate the decision before us and remand the case to the trial court for further proceedings consistent with that opinion. If we somehow go wrong in the details of how we structure this judicial exercise of equitable power, the Supreme Court, sooner or later, will correct us. It is better that the Supreme Court tell us that we did our duty incorrectly than that we failed to do it at all.

. The term "product” is used here to refer to any category of patentable subject matter. See 35 U.S.C. § 101 (1988).

. For commentary on the doctrine, and specific criticisms, see, e.g., Peter Blackman, Doctrine of Equivalents; Ruling Unlikely to Resolve Tension in Patent Law, N.Y.L.J., July 21, 1994, Corporate Update, at 5; Rudolph P. Hofmann, Jr., The Doctrine of Equivalents: Twelve Years of Federal Circuit Precedent Still Leaves Practitioners Wondering, Wm. Mitchell L.Rev. 1033 (1994); Paul C. Craane, Comment, At the Boundaries of Law and Equity: The Court of Appeals for the Federal Circuit and the Doctrine of Equivalents, 13 N.Ill. U.L.Rev. 105 (1992).

. The jury's findings on infringement consisted in its entirety of the following:

We the Jury, unanimously find that plaintiff Hilton Davis has proved by a preponderance of
Claim 1 Yes (infringed) X
Claim 2 Yes (infringed) X '
Claim 3 Yes (infringed) X
Claim 13 Yes (infringed) X
Claim 14 Yes (infringed) X
the legal evidence that defendant Warner-Jen-kinson has infringed upon the following claims of the Hilton Davis Patent:
No (not infringed)
No (not infringed)
No (not infringed)
No (not infringed)
No (not infringed)

. Unless otherwise noted, all citations to the United States Code are to the 1988 version.

. See T. Plunkett, A Concise History of the Common Law 191-98 (5th ed. 1956).

. In Transmatic, Inc. v. Gulton Indus., Inc., 835 F.Supp. 1026 (E.D.Mich.1993), the trial court held that plaintiff was not entitled to a jury trial on the issue of infringement under the doctrine of equivalents because, inter alia, infringement under the doctrine of equivalents is an action in equity to which the right to a jury does not attach. Accordingly, the trial judge, at the conclusion of the trial, rendered a ruling from the bench regarding the doctrine of equivalents, finding the claims at issue infringed under the doctrine. Transmatic, Inc. v. Gulton Indus., Inc., 849 F.Supp. 526 (E.D.Mich.1994). On appeal, we reversed, finding the claims at issue literally infringed, and therefore did not address infringement under the doctrine of equivalents. Transmatic, Inc. v. Gulton Indus., Inc., 53 F.3d 1270, 35 USPQ2d 1035 (Fed.Cir.1995).

. Prior to the merger of law and equity in the federal system, district courts sat in a particular case either in law or equity, as the nature of the case required, and employed separate rules of pleading and procedure. In 1938 these two bodies of jurisprudence were 'merged' so that there was only the one civil action, and only one form of pleading. Merger of the law and equity sides of course did not do away with the historical differences in judicial power, or change the relationship of judge and jury.

. This court has on several occasions signalled the need for a more disciplined analysis in these cases. See, e.g., Lear Siegler, Inc. v. Sealy Mattress Co. of Mich., Inc., 873 F.2d 1422, 1426, 10 USPQ2d 1767, 1770 (Fed.Cir.1989) (holding that the three Graver Tank factors must be presented in the form of "particularized testimony and linking argument” or the jury is "more or less put to sea without guiding charts when called upon to determine infringement under the doctrine.”); Malta v. Schulmerich Carillons, Inc., 952 F.2d 1320, 1330, 21 USPQ2d 1161 (Fed.Cir.1991) (Michel, J., concurring) ("[T]he danger that Lear Siegler, building directly on Nestier Corp. [v. Menasha Corp., 739 F.2d 1576] [Fed.Cir.1984], is designed to prevent is that of the doctrine of equivalents becoming 'a result oriented catchall.’ ”), reh'g denied, 959 F.2d 923 (Fed.Cir.), cert. denied, 504 U.S. 974, 112 S.Ct. 2942, 119 L.Ed.2d 566 (1992).