Chapter 6. Claim Construction. The Process of Claim Construction

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1 Chapter 6 Claim Construction The Process of Claim Construction With the splintering in the Federal Circuit you have just seen over who is to construe claims and what is to be considered, you can only imagine the problems encountered when it comes time to actually construe a claim. Thayer, in A PRELIMINARY TREATISE ON EVIDENCE (1898), expressed an ideal not present in the patent law: [a] lawyer s Paradise, where all words have a fixed, precisely ascertained meaning; where men may express their purposes, not only with accurracy, but with fullness; and where, if the writer has been careful, a lawyer, having a document referred to him, may sit in his chair, inspect the text, and answer all questions without raising his eyes. This land is even more fantastical when populated with patents, for a patent attempts to combine the particular challenges of a specialized field of technology with the separate challenges of a particularized field of law. The Supreme Court recognized the difficulty of patent drafting over a century ago when it observed: The specification and claims of a patent, particularly if the invention be at all complicated, constitute one of the most difficult legal instruments to draw with accuracy.... Topliff v. Topliff, 145 U.S. 156, 171 (1892). The following recent opinions of the Federal Circuit demonstrate that court s post-markman efforts to bring order to the claim construction process. Chapter 6 Claim Construction 1

2 Vitronics v. Conceptronics 90 F.3d 1576, 39 USPQ2d 1573 (Fed. Cir. 1996) Before MICHEL and LOURIE, Circuit Judges, and FRIEDMAN, Senior Circuit Judge. MICHEL, Circuit Judge. Vitronics and Conceptronic both manufacture ovens used in the production of printed circuit boards. The ovens are used to solder electrical devices (such as resistors, capacitors and integrated circuits) to the boards. Several methods of soldering devices to boards have been developed; the '502 patent, assigned to Vitronics, is directed to one of those methods. Specifically, the '502 patent is directed to a method for the reflow soldering of surface mounted devices to a printed circuit board in which the circuit board is moved by a conveyor through a multizone oven. Prior to trial, the parties stipulated that every limitation of claim 1 of the '502 patent was met by the HVC series of ovens, except the limitation requiring the utilization of "nonfocused infrared panel emitters" and the limitation that the temperature of the devices must be maintained below the "solder reflow temperature." Vitronics contended that, as used in the claim, solder reflow temperature means peak reflow temperature, i.e., a temperature approximately 20 C above the liquidus temperature, at which the solder is completely melted and moves freely. Conceptronic, on the other hand, contended that solder reflow temperature means 183 C, i.e., the liquidus temperature of a particular type of solder known as 63/37 (Sn/Pb) solder. The district court delayed construing the disputed language until the close of testimony, at which time it ruled in favor of Conceptronic and concluded that the term "solder reflow temperature" as used in claim 1 refers to 183 C. Vitronics then conceded that the court was required to grant judgment as a matter of law in favor of Conceptronic, as Vitronics had not presented any evidence of infringement under the court's interpretation of solder reflow temperature. This appeal followed. Claim Construction Aids Before the District Court The Patent Specification Vitronics relied heavily upon the patent itself to support its asserted claim construction. Although Vitronics conceded that the term "solder reflow temperature" may be ambiguous when considered in isolation, it argued that the specification clearly shows that, as used in the claim, solder reflow temperature means peak reflow temperature rather than the liquidus temperature. In particular, Vitronics pointed to that part of the specification that describes a preferred embodiment: A preferred embodiment of the invention for reflow soldering of surface mounted devices to printed circuit boards will now be described. The printed circuit boards are typically made of epoxy-glass, such as fire retardant 4(FR-4), or polyamide glass. These boards typically degrade above temperatures of 225 C. The solder may be, for example, 60/40 (Sn/Pb), 63/37 (Sn/Pb), or 62/36/2 (Sn/Pb/Ag), all of which have a liquidus temperature (i.e. begin to melt) of about 190 C and a peak reflow temperature of about C. Thus, to effect reflow soldering without damaging the board, the solder must be allowed to reach a temperature of at least 210 C, but the board cannot reach a temperature of 225 C. The board is then sent into a fifth zone 5 to bring the temperature of the board up to a temperature of approximately 210 C, the devices up to approximately 195 C, and the solder up to approximately 210 C for a period of time of Chapter 6 Claim Construction 2

3 from about 10 to about 20 seconds to cause the solder to flow. Because the devices are cooler than the board, the solder flows up the devices.... The board spends approximately 60 seconds in the fifth zone, but only about 10 to 20 seconds at 210 C. Thus, the board is at the solder reflow temperature for only a short period of time and the devices never reach the solder reflow temperature. Vitronics pointed out that, in the example described as the preferred embodiment, the temperature of the solder is raised to 210 C, the peak reflow temperature, and the temperature of the devices is raised to 195 C, 5 above the 190 C liquidus temperature. Thus, as argued by Vitronics, the term "solder reflow temperature" must be construed so that it refers to the peak reflow temperature because the claim requires that the temperature of the devices be maintained below "said solder reflow temperature"; if solder reflow temperature were construed to refer to liquidus temperature, the preferred embodiment would not be covered by the patent claims. Expert Testimony Conceptronic relied heavily on the expert testimony of Dr. Rothe. Dr. Rothe testified that the meaning of the term "solder reflow temperature" in claim 1 is synonymous with liquidus temperature. Dr. Rothe further testified that the solder reflow temperature for 63/37 (Sn/Pb) is 183 C. Dr. Rothe likewise testified at trial that several technical articles written by those skilled in the art supported his view that solder reflow temperature refers to liquidus temperature. The Testimony of Mr. Hall Conceptronic also relied on the testimony of Mr. Hall, the Chief Engineer at Vitronics. At trial, Mr. Hall confirmed that during his deposition he had testified that the reflow temperature of solder was 183 C. Mr. Hall also testified that, during his deposition, he had used solder reflow temperature to refer to liquidus temperature. However, at another point in his trial testimony, Hall explained that, while in his earlier deposition testimony he had used solder reflow temperature to refer to liquidus temperature, he did not suggest that was how the term was used in the patent. Rather, Hall testified the patent uses the term to refer to the peak reflow temperature. Paper Written By Former Vitronics Employee Conceptronic also introduced into evidence a paper written by Phillip Zarrow, a former employee of Vitronics, defining solder reflow temperature in the following manner: "As the temperature of the solder paste on the interconnect passes the solder alloy's melting point and the solder enters a molten state, the assembly enters the reflow region of the process. For 63 Sn/37 Pb, a eutectic solder and the most common SMT alloy, reflow occurs at 183 C." Phillip Zarrow, Convection/Infrared and Convection Dominant Reflow Soldering of Fine Pitch SMT Devices, (1994). However, that same paper later describes the solder reflow process as taking the temperature of the solder above liquidus: "Most solder manufacturers recommend bringing the interconnection temperature approximately 15 to 25 C above the alloy melting point to achieve full liquidus and assure good solder flow and aid fillet formation." Id. Memorandum of Plaintiff Vitronics Corporation in Opposition to Motion for Summary Judgment of Defendant Conceptronic Corporation and In Support of Plaintiff's Cross- Motion for Summary Judgment of Patent Validity and Infringement In its brief supporting its proposed construction of claim 1, both at the trial court level and here on appeal, Conceptronic similarly relied on a memorandum written by Vitronics which contains the following language: "Tin/lead solders commonly used by the electronic products industry have a liquidus or reflow temperature in the order of 183 C, or about 361 F." However, this phrase is in Chapter 6 Claim Construction 3

4 the background section of the memorandum and later in the same memorandum, Vitronics discussed the issue of infringement as being whether the temperature of the devices was maintained below "the temperatures of the leads at which the solder is reflowing." Without indicating which evidence it relied upon, the district court simply ruled that solder reflow temperature meant 183 C. The Use of Intrinsic and Extrinsic Evidence in Claim Construction A literal patent infringement analysis involves two steps: the proper construction of the asserted claim and a determination as to whether the accused method or product infringes the asserted claim as properly construed.... The first step, claim construction, is a matter of law, which we review de novo. Claim construction is the only step in the infringement analysis at issue in this appeal. In determining the proper construction of a claim, the court has numerous sources that it may properly utilize for guidance. These sources have been detailed in our previous opinions, as discussed below, and include both intrinsic evidence (e.g., the patent specification and file history) and extrinsic evidence (e.g., expert testimony). It is well-settled that, in interpreting an asserted claim, the court should look first to the intrinsic evidence of record, i.e., the patent itself, including the claims, the specification and, if in evidence, the prosecution history. Such intrinsic evidence is the most significant source of the legally operative meaning of disputed claim language. First, we look to the words of the claims themselves, both asserted and nonasserted, to define the scope of the patented invention. Although words in a claim are generally given their ordinary and customary meaning, a patentee may choose to be his own lexicographer and use terms in a manner other than their ordinary meaning, as long as the special definition of the term is clearly stated in the patent specification or file history. Thus, second, it is always necessary to review the specification to determine whether the inventor has used any terms in a manner inconsistent with their ordinary meaning. The specification acts as a dictionary when it expressly defines terms used in the claims or when it defines terms by implication. As we have repeatedly stated, "[c]laims must be read in view of the specification, of which they are a part." Markman. The specification contains a written description of the invention which must be clear and complete enough to enable those of ordinary skill in the art to make and use it. Thus, the specification is always highly relevant to the claim construction analysis. Usually, it is dispositive; it is the single best guide to the meaning of a disputed term. Third, the court may also consider the prosecution history of the patent, if in evidence. This history contains the complete record of all the proceedings before the Patent and Trademark Office, including any express representations made by the applicant regarding the scope of the claims. As such, the record before the Patent and Trademark Office is often of critical significance in determining the meaning of the claims. Southwall Tech., Inc. v. Cardinal IG Co., 54 F.3d 1570, 1576, 34 USPQ2d 1673, 1676 (Fed. Cir. 1995) ("The prosecution history limits the interpretation of claim terms so as to exclude any interpretation that was disclaimed during prosecution.") (citations omitted). Included within an analysis of the file history may be an examination of the prior art cited therein. Autogiro Co. of America v. United States, 384 F.2d 391, 399, 155 USPQ 697, 704 (Ct. Cl. 1967) ("In its broader use as source material, the prior art cited in the file wrapper gives clues as to what the claims do not cover."). Chapter 6 Claim Construction 4

5 In most situations, an analysis of the intrinsic evidence alone will resolve any ambiguity in a disputed claim term. In such circumstances, it is improper to rely on extrinsic evidence. In those cases where the public record unambiguously describes the scope of the patented invention, reliance on any extrinsic evidence is improper. The claims, specification, and file history, rather than extrinsic evidence, constitute the public record of the patentee's claim, a record on which the public is entitled to rely. In other words, competitors are entitled to review the public record, apply the established rules of claim construction, ascertain the scope of the patentee's claimed invention and, thus, design around the claimed invention. Allowing the public record to be altered or changed by extrinsic evidence introduced at trial, such as expert testimony, would make this right meaningless. See Southwall, 54 F.3d at 1578, 34 USPQ2d at 1678 ("A patentee may not proffer an interpretation for the purposes of litigation that would alter the indisputable public record consisting of the claims, the specification and the prosecution history, and treat the claims as a nose of wax ). The same holds true whether it is the patentee or the alleged infringer who seeks to alter the scope of the claims. The Proper Construction of the Claim Term "Solder Reflow Temperature" As can be readily seen from those portions of the specification set forth above, the meaning of the disputed term "solder reflow temperature" in claim 1 of the '502 patent is clear from a reading of the claim itself and the patent specification. The "peak reflow temperature" and "liquidus temperature" are clearly defined in the specification as having distinctly different meanings. Specifically, for the solders described in the specification, liquidus temperature is about 190 C and the peak reflow temperature is about 210 to 218 C. Moreover, in the preferred embodiment described in the patent, the solder is heated to a temperature of 210 C but the temperature of the devices is maintained at approximately 195 C, i.e., below the peak reflow temperature (210 C) but above the liquidus temperature (190 C). Therefore, in order to be consistent with the specification and preferred embodiment described therein, claim 1 must be construed such that the term "solder reflow temperature" means the peak reflow temperature, rather than the liquidus temperature. Indeed, if "solder reflow temperature" were defined to mean liquidus temperature, a preferred (and indeed only) embodiment in the specification would not fall within the scope of the patent claim. Such an interpretation is rarely, if ever, correct and would require highly persuasive evidentiary support, which is wholly absent in this case. The District Court's Reliance on Extrinsic Evidence Since the claim, read in light of the patent specification, clearly uses the term "solder reflow temperature" to mean the peak reflow temperature, rather than the liquidus temperature, that should have been the end of the trial court's analysis. Only if there were still some genuine ambiguity in the claims, after consideration of all available intrinsic evidence, should the trial court have resorted to extrinsic evidence, such as expert testimony, in order to construe claim 1. Moreover, even if the judge permissibly decided to hear all the possible evidence before construing the claim, the expert testimony, which was inconsistent with the specification and file history, should have been accorded no weight..... Here, the trial judge considered not only the specification, but also expert testimony and other extrinsic evidence, such as the paper written by the former Vitronics employee. No doubt there will be instances in which intrinsic evidence is insufficient to enable the court to determine the meaning of the asserted claims, and in those instances, extrinsic evidence, such as that relied on by the district court, may also properly be relied on to understand the technology and to construe the claims. Extrinsic evidence is that evidence which is external to the patent and file history, such as expert testimony, inventor testimony, dictionaries, and technical treatises and articles. 6 However, as we have recently re- 6 Although technical treatises and dictionaries fall within the category of extrinsic evidence, as theyk do not form a part of an integrated patent document, they are worthy of special note. Judges are free to consult such resources at any time in order to better understand the underlying technology and may also rely on Chapter 6 Claim Construction 5

6 emphasized, extrinsic evidence in general, and expert testimony in particular, may be used only to help the court come to the proper understanding of the claims; it may not be used to vary or contradict the claim language. Nor may it contradict the import of other parts of the specification. Indeed, where the patent documents are unambiguous, expert testimony regarding the meaning of a claim is entitled to no weight. Any other rule would be unfair to competitors who must be able to rely on the patent documents themselves, without consideration of expert opinion that then does not even exist, in ascertaining the scope of a patentee's right to exclude. Such testimony cannot guide the court to a proper interpretation when the patent documents themselves do so clearly. In addition, a court in its discretion may admit and rely on prior art proffered by one of the parties, whether or not cited in the specification or the file history. This prior art can often help to demonstrate how a disputed term is used by those skilled in the art. Such art may make it unnecessary to rely on expert testimony and may save much trial time. As compared to expert testimony, which often only indicates what a particular expert believes a term means, prior art references may also be more indicative of what all those skilled in the art generally believe a certain term means. Once again, however, reliance on such evidence is unnecessary, and indeed improper, when the disputed terms can be understood from a careful reading of the public record. Nor may it be used to vary claim terms from how they are defined, even implicitly, in the specification or file history. Johnson Worldwide v. Zebco 175 F.3d 985 (Fed. Cir. 1999) Before MAYER, Chief Judge, CLEVENGER, and GAJARSA, Circuit Judges. CLEVENGER, Circuit Judge. I Johnson is the holder of the '835 patent, which is generally directed to a steering control apparatus for small outboard motors, such as electric trolling motors. Trolling motors are an alternate propulsion source for small watercraft, generally intended for use while actively fishing--when the noise, vibration, and speed caused by larger or more powerful motors would diminish the chances of enticing fish to the proffered bait. A In broad terms, the invention of the '835 patent is a form of autopilot, described in the patent as a "heading lock," enabling directional control over the watercraft to be maintained without constant manipulation of trolling motor controls. The preferred embodiment of the '835 patent, as set forth in the written description and figures, employs a compass mounted to the head of the "heading lock" unit, which monitors the direction of the thrust motor, specifically noting that the direction of the thrust motor is considered to be the same as the direction of the boat, as the trolling motor is mounted on the bow of the boat. See '835 patent, col. 4, lines Claim 1 of the '835 patent, the only independent claim alleged to be infringed, provides as follows: dictionary definitions when construing claim terms, so long as the dictionary definition does not contradict any definition found in or ascertained by a reading of the patent documents. Chapter 6 Claim Construction 6

7 1. A heading lock coupled to a trolling motor producing a thrust disposed to pull a watercraft, said heading lock comprising: a steering motor coupled to said trolling motor, said steering motor being disposed to affect the orientation of said trolling motor in response to input signals; a steering circuit electrically coupled to said steering motor, said steering circuit [being] disposed to generate said input signals to said steering motor in response to heading signals; and a heading detector electrically coupled to said steering circuit, said heading detector being disposed to transmit said heading signals to said steering circuit. Zebco sells a product under the trade name "AutoGuide" that maintains directional control of a trolling motor by use of a magnetometer located in a foot pedal. The foot pedal also contains the user controls. A microprocessor in the foot pedal sends steering signals to the steering motor through wires connecting the foot pedal to the trolling motor unit. The location of the magnetometer (in the foot pedal) is thus distinct from the location of the compass (fixed to the trolling motor head) depicted in the preferred embodiment of the '835 patent. Whether this fact is sufficient for Zebco to escape infringement of the '835 patent is the subject of this appeal. II As we alluded to above, the crux of Zebco's argument is that the '835 patent covers only those trolling motor-autopilot systems that include a compass or other directional indicator physically attached to the trolling motor.... While Zebco recognizes that claim 1, the broadest claim at issue, does not explicitly require that the "heading detector" be mechanically coupled to the trolling motor, it nonetheless suggests [**8] that a proper interpretation of the terms "heading signal" and "coupled" in the language of claim 1 compels such a limited claim scope. In doing so, Zebco points out that Figure 1 of the '835 patent, and at least some of the language in the written description, suggest that the preferred embodiment of the invention includes a compass mechanically attached to the trolling motor. This case, then, presents the question of when it is permissible to narrow the scope of broad claim language by reference to embodiments described and depicted in the balance of the specification. A Chapter 6 Claim Construction 7

8 We begin, as with all claim interpretation analyses, with the language of the claims.... The general rule is, of course, that terms in the claim are to be given their ordinary and accustomed meaning.... General descriptive terms will ordinarily be given their full meaning; modifiers will not be added to broad terms standing alone. See, e.g., Virginia Panel Corp. v. MAC Panel Co., 133 F.3d 860, , 45 U.S.P.Q.2D (BNA) 1225, 1229 (Fed. Cir. 1997) (unmodified term "reciprocating" not limited to linear reciprocation); Bell Communications, 55 F.3d at , 34 U.S.P.Q.2D (BNA) at 1821 (unmodified term "associating" not limited to explicit association); Specialty Composites v. Cabot Corp., 845 F.2d 981, 987, 6 U.S.P.Q.2D (BNA) 1601, 1606 (Fed. Cir. 1988) (unmodified term "plasticizer" given full range of ordinary and accustomed meaning). In short, a court must presume that the terms in the claim mean what they say, and, unless otherwise compelled, give full effect to the ordinary and accustomed meaning of claim terms.... In order to overcome this heavy presumption in favor of the ordinary meaning of claim language, it is clear that "a party wishing to use statements in the written description to confine or otherwise affect a patent's scope must, at the very least, point to a term or terms in the claim with which to draw in those statements." Renishaw, 158 F.3d at 1248, 48 U.S.P.Q.2D (BNA) at That is, claim terms cannot be narrowed by reference to the written description or prosecution history unless the language of the claims invites reference to those sources. See, e.g., McCarty v. Lehigh Valley R.R., 160 U.S. 110, 116, 40 L. Ed. 358, 16 S. Ct. 240 (1895) ("If we once begin to include elements not mentioned in the claim in order to limit such claim..., we should never know where to stop."); Renishaw, 158 F.3d at 1249, 48 U.S.P.Q.2D (BNA) at In other words, there must be a textual reference in the actual language of the claim with which to associate a proffered claim construction. Our case law demonstrates two situations where a sufficient reason exists to require the entry of a definition of a claim term other than its ordinary and accustomed meaning. The first arises if the patentee has chosen to be his or her own lexicographer by clearly setting forth an explicit definition for a claim term..... The second is where the term or terms chosen by the patentee so deprive the claim of clarity that there is no means by which the scope of the claim may be ascertained from the language used..... In these two circumstances, a term or terms used in the claim invites--or indeed, requires-- reference to intrinsic, or in some cases, extrinsic, evidence, see Vitronics (reference to extrinsic evidence is proper when intrinsic evidence cannot resolve ambiguity in claim language), to determine the scope of the claim language. B Here, Zebco's primary claim interpretation argument is that the term "heading" in the phrase "heading signal" refers only to the direction of the trolling motor, thus requiring that the heading detector, "being disposed to transmit said heading signals," must be affixed to the trolling motor. Zebco, of course, recognizes that the ordinary and accustomed meaning of "heading" connotes only direction, rather than being limited to the direction of the trolling motor. Thus Zebco argues, as it must, for a more limited scope of "heading," to overcome the presumption in favor of the ordinary--and, in this case, broader-- meaning. Because Zebco does not suggest that the phrase "heading signal" lacks clarity as it is used in the claim, in order to establish a reason to import a narrow definition of the term, it must instead argue that the term "heading" has been given a particular meaning by the patentee. To this end, Zebco argues that language throughout the written description and prosecution history of the '835 patent demonstrates that "heading" in the context of the '835 patent is limited to the direction of the trolling motor. We find this unpersuasive, as did the district court. First, the written description does not describe "with reasonable clarity, deliberateness, and precision" the definition of "heading" proposed by Zebco..... Indeed, the many uses of the term throughout the '835 patent are consistent with a broader definition, one Chapter 6 Claim Construction 8

9 encompassing the directions of both the boat and the trolling motor unit. Compare, e.g., '835 patent, col. 3, lines ("The electronic steering system of the present invention continues to monitor the current heading of the thrust motor" (emphasis added)) with '835 patent, col. 7, lines ("Heading detector 204 continuously monitors the current heading of the boat" (emphasis added)). Varied use of a disputed term in the written description demonstrates the breadth of the term rather than providing a limited definition..... That the term "heading" is used at various points in the written description to refer to both the direction of the trolling motor and the [**15] boat is simply not "a special and particular definition created by the patent applicant," Renishaw, and is thus an insufficient reason to limit the scope of the term.....we therefore agree with the district court that the ordinary and accustomed meaning of "heading signal" controls. C Zebco's second interpretive argument is that the term "coupled" in the phrase "[a] heading lock coupled to a trolling motor" found in the preamble of claim 1 is limited to a mechanical or physical coupling. We are unpersuaded. Even assuming--as did the district court and Zebco--that the language of the preamble of claim 1 constitutes limitations on the claim rather than mere description, see Bell Communications, 55 F.3d at 620, 34 U.S.P.Q.2D (BNA) at 1820 (Fed. Cir. 1995) ("When the claim drafter chooses to use both the preamble and the body to define the subject matter of the claimed invention, the invention so defined, and not some other, is the one the patent protects."), Zebco cannot demonstrate that a limitation to the broad and general term "coupled" must be read into the claim. As with "heading signal," Zebco (a) recognizes that the unmodified term "coupled" generically describes a connection, and does not require a mechanical or physical coupling; and (b) does not suggest that "coupled," as used in the preamble, lacks clarity. Instead, Zebco points to passages of the written description implying the relationship between elements of the preferred embodiment, and argues [**19] that such language constitutes a special (and limited) definition of "coupled." For example, Zebco argues that the phrase "feedback means for providing a feedback signal to the control means, wherein the feedback signal is indicative of the direction of thrust," '825 patent, col. 2, lines 32-34, defines "coupled" to mean "mechanically coupled." However, just as the preferred embodiment itself does not limit claim terms, mere inferences drawn from the description of an embodiment of the invention cannot serve to limit claim terms, as they are insufficient to require a narrower definition of a disputed term....because Zebco has not shown a sufficient reason to alter the clear meaning of the term "coupled," we agree with the district court that the term is not limited to a mechanical or physical coupling. AFFIRMED Questions, Comments, Problems 1. The Vitronics opinion is currently the most-cited opinion on claim construction at the Federal Circuit, and respresents the general analytical process for construing claims. Everything you ever needed to know about an uncomplicated claim construction analysis is in Vitronics (of course, very seldom is a claim construction uncomplicated). In Vitronics, the patentee was arguing for a broader construction of the claims than was the accused infringer because the patentee was attempting to cover the accused infringer s method with its claims. However, claim breadth cuts both ways: a patent applicant must keep its claims sufficiently narrow to avoid sweeping in the prior art, but sufficiently broad to encompass the accused devices or processes. Often, the applicant must do this before it is aware of all the relevant prior art and before the accused device even exists. The patent claim that achieves both these goals will make the patentee wealthy, but the claim that fails will set the accused infringer free. Luckily, a patent applicant Chapter 6 Claim Construction 9

10 receives more than one shot at drafting the perfect claim. An applicant may, and should, submit many claims of differing breadth, and the patentee may choose to sue on any of the claims in the patent. In his usual style, then-district Judge Hand discussed the practice of differentiating an invention from the prior art by drafting claims of varying breadth: There is nothing improper, so far as I can see, in first putting your claims as broadly as in good faith you can, and then, ex abundanti cautela, following them successively with narrower claims designed to protect you against possible anticipations of which you are not yet aware. Indeed, the very case upon which the defendant relies (Matheson v. Campbell, 78 Fed. 910, 917, 24 C.C.A. 384) shows the necessity of claims as broad as one can honestly support. If any one of the specified differentia of the claim is missing, the defendant's product does not infringe; if any anticipation includes all the differentia, the claim is bad. To pass between this Scylla and the Charybdis, I think a patentee may fairly be entitled to bend sails upon many yards. The question as to whether or not he is acting colorably is not answerable on general principles. He may, of course, attempt to monopolize more than was fairly his due, but in this case I have already said that I do not think he did so, especially as he was the first person who had ever isolated a nonsalt substance relatively pure. Parke-Davis & Co. v. H.K. Mulford Co., 189 F. 95 (C.C.S.D.N.Y. 1911) 2. Extrinsic Evidence The Vitronics intrinsic/extrinsic approach puts limits on what evidence the district court may consider. However, does that mean that the district court may not even hear extrinsic evidence if the claim is unambiguous based on the intrinsic evidence, or just that the court may not rely on it in construing the claim? Judge Rader, who dissented from the majority pronouncements in Cybor, supra, would give the district court latitude with respect to hearing extrinsic evidence, as seen by his majority opinion in a pre-cybor case, Eastman Kodak Co. v. Goodyear Tire & Rubber Co., 114 F.3d 1547, 1555, 42 USPQ2d 1737 (Fed. Cir. 1997): Accordingly, the district court properly consulted extrinsic evidence relevant to claim meaning. As a general rule, the construing court interprets words in a claim as one of skill in the art at the time of invention would understand them. See Intellicall, Inc. v. Phonometrics, Inc., 952 F.2d 1384, 1387, 21 USPQ2d 1383, 1386 (Fed. Cir. 1992). Therefore, the testimony of one skilled in the art about the meaning of claim terms at the time of the invention will almost always qualify as relevant evidence. Fed. R. Evid. 401; Markman, 52 F.3d at 981 (In "pronouncing the meaning of claim language as a matter of law based on the patent documents themselves... the court is looking to the extrinsic evidence [i.e., testimony of one skilled in the art] to assist in its construction of the written document, a task it is required to perform."). If, of course, the meaning of the claims is clear from their language in view of the context provided by the specification and the prosecution history, the trial court should limit its consideration of extrinsic evidence. See Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1583, 39 USPQ2d 1573, 1577 (Fed. Cir. 1996). Extrinsic evidence whether providing context for the claims or explaining claim meaning to one of skill in the art cannot contradict claim language. Id. The trial court is best situated to gauge the relevance and need for additional evidence to explicate claim terms. See International Communication Materials, Inc. v. Ricoh Co., 108 F.3d 316, , 41 USPQ2d 1957, 1958 (Fed. Cir. 1997) (allowing the trial judge to complete the picture by developing a more complete record ). Judge Lourie dissented-in-part, reasoning that [t]he claim is clear on its face, when read in light of the specification, and concluding that the majority used the expert testimony to contradict the clear meaning of the claim. A district court may end-run the limitation in Vitronics and Cybor on extrinsic evidence when such evidence would not be needed to construe the claims by stating that the court is considering the evidence only to better understand the technology involved in a suit. Thus, in Mantech Environmental Corp. v. Hudson Environmental Services., Inc., 47 USPQ2d 1732, 152 F.3d 1368 (Fed. Cir. 1998), an opinion authored, like Vitronics, by Circuit Judge Michel, the court stated: In this case, the district court was legally correct both in admitting and accepting the testimony of the parties expert witnesses for the purpose of background in the technical area at issue... and then basing its claim construction solely upon the intrinsic evidence. Chapter 6 Claim Construction 10

11 Id. at The Role of Dictionaries Did Vitronics go too far in admonishing the District Court for receiving extrinsic evidence? Unless every claim term is specifically defined in the written description, won t the court be relying on extrinsic evidence (e.g., common knowledge) to determine the meaning of undefined terms. For example, isn t the meaning of a common term like the word coupled at issue in Johnson Worldwide extrinsic to the patent document? The Vitronics court appears to have been aware of this, by setting forth, in footnote 6, the rule that court may consult and rely upon dictionary definititions of terms (as long as they don t conflict with a definition given in the patent document). But doesn t this rule conflict with the thrust of Vitronics? What, then, do you think the court s real concern was in Vitronics? 4. Canons of Claim Construction Much like statutory construction, courts often look to various canons for assistance in construing patent claims. For instance, courts will apply the oridinary meaning of a word unless it appears that the applicant intended a different meaning. Courts will also interpret a claim term consistently throughout the claims of a patent if possible. In the broader context of statutory construction, Professor Llewellyn considered the application of canons of construction, and came to the conclusion that many canons are unhelpful because they often may be countered by oppositely pointing canons. Llewellyn thus compiled a number of thrusts and parries of canons of statutory construction, some of which are included below: Thrust Parry 1 A statute may not go beyond its text. To effect its purpose a statute may be implemented beyond its text. 8 Where design has been distinctly stated no place is left for construction. 9 Definitions and rules of construction contained in an interpretation clause are part of the law and binding. 11 Titles do not control meaning; preambles do not expand scope; section headings do not change language. 12 If language is plain and unambiguous it must be given effect. 13 Words and phrases which have received judicial construction before enactment are to be understood according to that construction. 15 Words are to be taken in their ordinary meaning unless they are technical terms or words of art. 16 Every word and clause must be given effect. 17 The same language used repeatedly in the same connection is presumed to bear the same meaning throughout the statute. 20 Expression of one thing excludes another. Courts have the power to inquire into real as ditinct from ostensible purpose. Definitions and rules of construction in a statute will not be extended beyond their necessary import nor allowed to defeat intention otherwise manifested. The title may be consulted as a guide when there is doubt or obscurity in the body; preambles may be consulted to determine rationale, and thus the true construction of terms; section headings may be looked upon as part of the statute itself. Not when literal interpretation would lead to absurd or mischievous consequences or thwart manifest purpose. Not if the statute clearly requires them to have a different meaning. Popular words may bear a technical meaning and technical words may have a popular signification and they should be so construed as to agree with evident intention or to make the statute operative. If inadvertantly inserted or if repugnant to the rest of the statute, they may be rejected as surplusage. This presumption will be disregarded where it is necessary to assign different meanings to make the statute consistent. The language may fairly comprehend many different cases where some only are expressly mentioned by way of example. Chapter 6 Claim Construction 11

12 21 General terms are to receive a general construction. They may be limited by specific terms with which they are associated or by the scope and purpose of the statute. Karl N. Llewellyn, Remarks on the Theory of Appellate Decision and the Rules of Canons About How Statutes are to be Construed, 3 Vand. L. Rev. 395, (1950); see also William N. Eskridge, Jr. and Philip P. Frickey, Legislation: Statutes and the Creation of Public Policy (1988). How do each of these canons apply in the patent context? There has been very little scholarship since Markman that has looked outside the patent arena for guidance on claim construction. Perhaps such an article, comparing patent construction in light of Markman to construction of other written instruments, would be wellreceived. 4. The Hardest Easy Issue in Patent Law The two most commonly applied canons of claim construction are presented as a dual rule: one should construe claims in light of the written description, but one should never read a limitation into the claims from the written description. As stated, the rule appears to be straightforward, and is simply a recognition that, although the claim terms are paramount, they cannot be viewed in isolation. As noted in a famous remark by Oliver W. Holmes, Jr.: A word is not a crystal, transparent and unchanged, it is the skin of a living thought and may vary greatly in color and content according to the circumstances and the time in which it is used. Towne v. Eisner, 245 U.S. 418, 425 (1918). Thus, in the context of the peculiarities of patents and complex technologies, a rule simply stated is laboriously applied. It is typically difficult to determine in any given case when the written description is being used to sharpen the definition of a claim term or is instead being used improperly to limit that term. Johnson Worldwide reflects one attempt to bring structure to the application of these canons, by establishing a presumption in favor of the ordinary meaning of a claim term. Do you this is likely to be successful? Is it consistent with Vitronics? Another similar effort, undertaken prior to Johnson Worldwide (and, interestingly, by the author of that opinion Judge Clevenger) can be seen in Renishaw plc v. Marposs Societa per Azioni, 158 F.3d 1243, 48 USPQ2d 1117 (Fed. Cir. 1998): Absent a special and particular definition created by the patent applicant, terms in a claim are to be given their ordinary and accustomed meaning.... Thus, when a claim term is expressed in general descriptive words, we will not ordinarily limit the term to a numerical range that may appear in the written description or in other claims.... Nor may we, in the broader situation, add a narrowing modifier before an otherwise general term that stands unmodified in a claim.... For example, if an apparatus claim recites a general structure (e.g., a noun) without limiting that structure to a specific subset of structures (e.g., with an adjective), we will generally construe the claim to cover all known types of that structure that are supported by the patent disclosure.... However, a common meaning, such as one expressed in a relevant dictionary, that flies in the face of the patent disclosure is undeserving of fealty. As one of our predecessor courts stated in Liebscher v. Boothroyd, 258 F.2d 948 (CCPA 1958): Indiscriminate reliance on definitions found in dictionaries can often produce absurd results.... One need not arbitrarily pick and choose from the various accepted definitions of a word to decide which meaning was intended as the word is used in a given claim. The subject matter, the context, etc., will more often than not lead to the correct conclusion. Id. at Thus, where there are several common meanings for a claim term, the patent disclosure serves to point away from the improper meanings and toward the proper meaning. Ultimately, the interpretation to be given a term can only be determined and confirmed with a full understanding of what the inventors actually invented and intended to envelop with the claim.... The construction that stays true to the claim language and most naturally aligns with the patent's description of the invention will be, in the end, the correct construction.... A claim Chapter 6 Claim Construction 12

13 construction is persuasive, not because it follows a certain rule, but because it defines terms in the context of the whole patent. Id. at , 48 USPQ2d at In making its statement that logic, rather than rote adherence to canons, must guide claim construction, the Federal Circuit cited Llewellyn s article, where he stated: Plainly, to make any canon take hold in a particular instance, the construction contended for must be sold, essentially, by means other than the use of canon: The good sense of the situation and a simple construction of the available language to achieve that sense, by tenable means, out of the statutory language. Llewellyn, supra, at 401. Judge Hand recognized this same problem three-quarters of a century ago in Dorsey v. Pilot Electric Co., 32 F.2d 211 (2d Cir. 1929), and there reached a similar conclusion: The critical question in claim 1 is the phrase a bearing designed to hold the cover plate against movement away from the panel, and in claim 3, the phrase said knob also serves to exert a pressure which is transmitted to the cover plate for holding it in place. It is not enough merely to read the language of the claims; they must be construed with the disclosure. While it is, of course, true that they should not be exactly confined to it, it is equally true that they do not extend beyond its functional significance. There is no high road between these two alternatives, and most patent litigation consists in picking one's way. As in any other written instrument, words are capable of many meanings; we must translate them into the underlying purpose of their user. We have here to ascertain, so far as we can, what Driggs meant, and confine his monopoly to that. With even the courts recognizing the imprecision, do you think the dual canons, which are central to almost every claim construction problem, are helpful? Or do they simply provide a cover for a claim construction that the court has already reached? Can you think of a better way to analyze the relationship between the claims and the written description? 5. Claim Differentiation In the leading opinion on the subject of claim differentiation, written by then-chief Judge Markey for an in banc court, the Federal Circuit explained the doctrine: The district court thus read, via the specification, the 45 limitation of narrower claim 2, and the vertical limitation of narrower claim 3, into broader claim 1 and the other asserted claims. It is settled law that when a patent claim does not contain a certain limitation and another claim does, that limitation cannot be read into the former claim in determining either validity or infringement. [citations omitted] The reason for the rule is well illustrated here. Non-asserted claim 3 is specifically drawn to the structure of Figure 1. To interpret the asserted claims as though they were also drawn to that structure (or to its manner of operation) would be to render the asserted claims superfluous. In interpreting the asserted claims in light of the specification, the district court read limitations into them from other claims. That was error as a matter of law. SRI International v. Matsushita Elec. Corp., 775 F.2d 1107, 1122, 227 USPQ 577, (Fed. Cir. 1985) (in banc). How rigid is this doctrine? Chief Judge Markey, in the same year SRI was decided, noted that the doctrine enjoys an immutable and universally applicable status comparatively rare among rules of law. D.M.I., Inc. v. Deere & Co., 755 F.2d 1570, 1574, 225 USPQ 236, 239 (Fed. Cir. 1985). Later panels of the Federal Circuit have not held the doctrine in such high regard and have found ways to sidestep it. In Tandon Corp. v. United States Int l Trade Comm n, 831 F.2d 1017, 1028, 4 USPQ2d 1283, 1292 (Fed. Cir. 1987), the court (per Judge Newman) commented that the doctrine of claim differentiation does not allow unrestrained expansion of claims beyond the description of the invention in the specification, and explanations and representations made to the PTO in order to obtain allowance of the claims. The court added that two claims which read differently can cover the same subject matter. Id. at 1023, 4 USPQ2d at In O.I. Corp. v. Tekmar Co., 115 F.3d 1576, 42 USPQ2d 1777 (Fed. Cir. 1997), the court held that the [written] description provides a clear meaning for the language of the claim in this case and... it trumps the doctrine of claim differentiation. The doctrine normally applies between claims linked by Chapter 6 Claim Construction 13

14 dependency, but has been applied as between two independent claims. See Grain Processing Corp. v. American Maize-Prods. Corp., 840 F.2d 902, 911, 5 USPQ2d 1788, 1795 (Fed. Cir. 1988). 6. Lexicography It is well established that a patentee may be her own lexicographer. In other words, she may coin new words or new definitions for old words to describe her invention or parts of her invention. However, it the patentee wishes to be her own lexicographer, she must do so "with reasonable clarity, deliberateness, and precision." What level of clarity is reasonable clarity? How would you determine whether a definition was supplied deliberately? If a definition is supplied with reasonable clarity and deliberateness, but is hopelessly imprecise (even though there may already be a common, wellunderstood meaning for the relevant term), what is a court to do? 7. Product-by-Process Claims Product-by-process claims are product claims that are limited by the process of manufacturing the product. A simple example is glass made by the Pilkington float glass process. This claim would not cover the Pilkington float glass process nor would it cover glass made by any other process. Such a claim is used when it is difficult to describe a product and distinguish it from other products by its structure or properties alone, particularly where the structure or other characteristics are not clearly known. Describing a product by the process of making it is thus an empirical and safe way to comply with the second paragraph of section 112 and the enablement requirement. However, there are drawbacks to the use of product-by-process claims. First, they do not allow one to claim known or obvious products merely because the inventor has discovered a new process of making them. That was the holding of In re Thorpe, 777 F.2d 695, 227 USPQ 964 (Fed. Cir. 1985), an early decision of the Federal Circuit. Thus, process of manufacture limitations do not count for validity if the product itself is known or would have been obvious from the prior art. Thinking that the same principle should apply to infringement, the Federal Circuit in Scripps Clinic & Research Foundation v. Genentech, Inc., 927 F.2d 1565, , 18 USPQ2d 1001, (Fed. Cir. 1991), held that for infringement purposes, product-by-process claims are not limited to products prepared by the process set forth in the claims. Although a precedential decision of one Federal Circuit panel is binding on later panels, the court in Atlantic Thermoplastics Co. v. Faytex Corp., 970 F.2d 834, 23 USPQ2d 1481 (Fed. Cir. 1992), request for reharing in banc declined, 974 F.2d 1279, 23 USPQ2d 1801, 974 F.2d 1299, 24 USPQ2d 1138 (Fed. Cir. 1992), effectively achieved the same result by refusing to follow Scripps on the ground that Scripps conflicted with old decisions of the Supreme Court. According to the panel in Atlantic Thermoplastics, even though process limitations cannot be relied on to allow repatenting an old product, they must always be considered for infringement purposes. The panel s decision prompted Judge Rich to decry a mutiny. Nevertheless, the refusal of the court to take Atlantic Thermoplastics in banc probably means a majority of the court agrees with Atlantic Thermoplastic, not Scripps. Thus, one must be wary of adding process limitations to product claims. It may be that they are necessary in view of what is known about the product or difficulties in describing the product without reference to the process of making it. But they may create difficult infringement issues (e.g., requiring discovery of the infringer s manufacturing process) with no benefit on the validity side. 8. Recipe Claims v. Composition Claims In what came as a blow to many chemical patent practitioners, the Federal Circuit in 1995 handed down Exxon Chemical Patents, Inc. v. Lubrizol Corp., 35 USPQ2d 1801, 64 F.3d 1553 (Fed. Cir. 1995). Until Exxon, a typical way to claim a chemical composition was as a recipe of its ingredients, or, put another way, a mixture of its ingredients. This, of course, meant that infringement was determined by focussing on what was put into the chemical reaction pot, not by what resulted when the ingredients chemically reacted with each other and transformed into new chemicals. Such a claim was, in effect, a product-by-process claim to a chemical composition resulting from the mixing together of specified ingredients in specified amounts. Perhaps practitioners had gotten so used to claiming compositions this way that they took for granted that pertinent readers of the patents would so understand the claims. Not so for two judges of the Federal Circuit. Over a rigorous dissent by the late Judge Nies, Judges Clevenger and Plager disagreed with a district court s claim construction that Exxon s claim to a lubricating oil was a classic recipe claim, and instead held that it was a claim to a chemical composition. Because Exxon s infringement proofs were based on the construction of the claim as a recipe claim, namely, proof of what Lubrizol put into the reaction pot and mixed together, as opposed to what was actually in the pot at any point in time, the Federal Circuit reversed a jury verdict of literal infringement for Chapter 6 Claim Construction 14