Opinion ID: 779640
Heading Depth: 2
Heading Rank: 1

Heading: The Contours of Claim Construction

Text: 29 In construing claims, the analytical focus must begin and remain centered on the language of the claims themselves, for it is that language that the patentee chose to use to `particularly point[] out and distinctly claim[] the subject matter which the patentee regards as his invention.' 35 U.S.C. § 112, ¶ 2. Interactive Gift Express, Inc. v. Compuserve, Inc., 256 F.3d 1323, 1331, 59 USPQ2d 1401, 1406 (Fed.Cir.2001). The terms used in the claims bear a heavy presumption that they mean what they say and have the ordinary meaning that would be attributed to those words by persons skilled in the relevant art. See CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366, 62 USPQ2d 1658, 1662 (Fed.Cir.2002); K-2 Corp. v. Salomon S.A., 191 F.3d 1356, 1362-63, 52 USPQ2d 1001, 1004 (Fed.Cir.1999); Johnson Worldwide Assocs., Inc. v. Zebco Corp., 175 F.3d 985, 989, 50 USPQ2d 1607, 1610 (Fed.Cir.1999); Specialty Composites v. Cabot Corp., 845 F.2d 981, 986, 6 USPQ2d 1601, 1604 (Fed.Cir.1988). Moreover, unless compelled otherwise, a court will give a claim term the full range of its ordinary meaning as understood by persons skilled in the relevant art. See Rexnord Corp. v. Laitram Corp., 274 F.3d 1336, 1342, 60 USPQ2d 1851, 1854 (Fed. Cir.2001); Johnson Worldwide Assocs., 175 F.3d at 989, 50 USPQ2d at 1610; Specialty Composites, 845 F.2d at 986, 6 USPQ2d at 1604. 30 It has been long recognized in our precedent and in the precedent of our predecessor court, the Court of Customs and Patent Appeals, that dictionaries, encyclopedias and treatises are particularly useful resources to assist the court in determining the ordinary and customary meanings of claim terms. See Teleflex, Inc. v. Ficosa N. Am. Corp., 299 F.3d 1313, 1325, 63 USPQ2d 1374, 1380 (Fed.Cir.2002) (The ordinary meaning of a claim term may be determined by reviewing a variety of sources, including ... dictionaries and treatises.... (internal citations omitted)); CCS Fitness, 288 F.3d at 1366, 62 USPQ2d at 1662 ([O]ur precedents show that dictionary definitions may establish a claim term's ordinary meaning.); Optical Disc Corp. v. Del Mar Avionics, 208 F.3d 1324, 1334-35, 54 USPQ2d 1289, 1295 (Fed.Cir.2000) (For such ordinary meaning, we turn to the dictionary definition of the term.); Quantum Corp. v. Rodime, PLC, 65 F.3d 1577, 1581, 36 USPQ2d 1162, 1166 (Fed.Cir.1995) ([W]e see no error in the district court's use of dictionary definitions to ascertain the ordinary meaning of the relevant claim limitation.); In re Ripper, 36 C.C.P.A. 743, 171 F.2d 297, 299, 80 USPQ 96, 98 (1948) ([I]t is clear that in ascertaining the meaning of [the claim term] as it appears herein, reference properly may be made to the ordinary dictionaries.). 31 Dictionaries are always available to the court to aid in the task of determining meanings that would have been attributed by those of skill in the relevant art to any disputed terms used by the inventor in the claims. See Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1584 n. 6, 39 USPQ2d 1573, 1578 n. 6 (Fed.Cir.1996) ([T]echnical treatises and dictionaries ... are worthy of special note. Judges are free to consult such resources at any time... and may also rely on dictionary definitions when construing claim terms....); Cybor Corp., 138 F.3d at 1459, 46 USPQ2d at 1177 (citing Vitronics for the proposition that a court is free to consult dictionaries, encyclopedias, and treatises at any time to help determine the meaning of claim terms); Vanguard Prods. Corp. v. Parker Hannifin Corp., 234 F.3d 1370, 1372, 57 USPQ2d 1087, 1089 (Fed.Cir.2000) (A dictionary is not prohibited extrinsic evidence, and is an available resource of claim construction.). 32 When a patent is granted, prosecution is concluded, the intrinsic record is fixed, and the public is placed on notice of its allowed claims. Dictionaries, ency-clopedias and treatises, publicly available at the time the patent is issued, are objective resources that serve as reliable sources of information on the established meanings that would have been attributed to the terms of the claims by those of skill in the art. Such references are unbiased reflections of common understanding not influenced by expert testimony or events subsequent to the fixing of the intrinsic record by the grant of the patent, not colored by the motives of the parties, and not inspired by litigation. Indeed, these materials may be the most meaningful sources of information to aid judges in better understanding both the technology and the terminology used by those skilled in the art to describe the technology. 33 These materials serve as important resources to assist courts in many ways. For example, they are often used to aid in the interpretation of statutes and regulations and in the interpretation of terms used in contracts. See, e.g., Rocknel Fastener, Inc. v. United States, 267 F.3d 1354, 1356-57 (Fed.Cir.2001) (advising that the interpretation of tariff terms, a matter of statutory construction, may be aided by reviewing dictionaries, scientific authorities, and other reliable information sources (citations omitted)); Am. Express Co. v. United States, 262 F.3d 1376, 1381 n. 5 (Fed.Cir.2001) (in interpreting Internal Revenue Service regulations and procedures, [i]t is appropriate to consult dictionaries to discern the ordinary meaning of a term not explicitly defined by statute or regulation); Bowers v. Baystate Techs., 302 F.3d 1334, 1345-46 (Fed.Cir. 2002) (construing contract terms using non-technical and technical dictionaries); Buchanan v. Dep't of Energy, 247 F.3d 1333, 1339 (Fed.Cir.2001) (relying on a dictionary definition in construing a settlement agreement). These materials deserve no less fealty in the context of claim construction. 34 As resources and references to inform and aid courts and judges in the understanding of technology and terminology, it is entirely proper for both trial and appellate judges to consult these materials at any stage of a litigation, regardless of whether they have been offered by a party in evidence or not. Thus, categorizing them as extrinsic evidence or even a special form of extrinsic evidence is misplaced and does not inform the analysis. 35 Because words often have multiple dictionary definitions, some having no relation to the claimed invention, the intrinsic record must always be consulted to identify which of the different possible dictionary meanings of the claim terms in issue is most consistent with the use of the words by the inventor. See Dow Chem. Co. v. Sumitomo Chem. Co., 257 F.3d 1364, 1372-73, 59 USPQ2d 1609, 1614 (Fed.Cir.2001); Multiform Desiccants, Inc. v. Medzam, Ltd., 133 F.3d 1473, 1478, 45 USPQ2d 1429, 1433 (Fed.Cir.1998). If more than one dictionary definition is consistent with the use of the words in the intrinsic record, the claim terms may be construed to encompass all such consistent meanings. Rexnord, 274 F.3d at 1343, 60 USPQ2d at 1858 (holding that the claim term portion may be interpreted in accordance with the dictionary definitions to encompass both separate and integral parts of an object). The objective and contemporaneous record provided by the intrinsic evidence is the most reliable guide to help the court determine which of the possible meanings of the terms in question was intended by the inventor to particularly point out and distinctly claim the invention. See Renishaw PLC v. Marposs Societa' per Azioni, 158 F.3d 1243, 1250, 48 USPQ2d 1117, 1122 (Fed.Cir.1998) (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.). 36 Moreover, the intrinsic record also must be examined in every case to determine whether the presumption of ordinary and customary meaning is rebutted. See id. Indeed, the intrinsic record may show that the specification uses the words in a manner clearly inconsistent with the ordinary meaning reflected, for example, in a dictionary definition. In such a case, the inconsistent dictionary definition must be rejected. See id. ([A] common meaning, such as one expressed in a relevant dictionary, that flies in the face of the patent disclosure is undeserving of fealty.); Liebscher v. Boothroyd, 46 C.C.P.A. 701, 258 F.2d 948, 951, 119 USPQ 133, 135 (1958) (Indiscriminate reliance on definitions found in dictionaries can often produce absurd results.). In short, the presumption in favor of a dictionary definition will be overcome where the patentee, acting as his or her own lexicographer, has clearly set forth an explicit definition of the term different from its ordinary meaning. See In re Paulsen, 30 F.3d 1475, 1480, 31 USPQ2d 1671, 1674 (Fed.Cir.1994); Intellicall, Inc. v. Phonometrics, Inc., 952 F.2d 1384, 1387-88, 21 USPQ2d 1383, 1386 (Fed.Cir.1992). Further, the presumption also will be rebutted if the inventor has disavowed or disclaimed scope of coverage, by using words or expressions of manifest exclusion or restriction, representing a clear disavowal of claim scope. See Teleflex, 299 F.3d at 1324, 63 USPQ2d at 1380. 37 Consulting the written description and prosecution history as a threshold step in the claim construction process, before any effort is made to discern the ordinary and customary meanings attributed to the words themselves, invites a violation of our precedent counseling against importing limitations into the claims. See, e.g., Generation II Orthotics Inc. v. Medical Technology Inc., 263 F.3d 1356, 1367, 59 USPQ2d 1919, 1928 (Fed.Cir.2001) (The district court should have construed the claim limitation `controlled' according to its ordinary and accustomed meaning [citing medical dictionary], rather than importing a characteristic of a disclosed or preferred embodiment into that term.); Loctite Corp. v. Ultraseal Ltd., 781 F.2d 861, 867, 228 USPQ 90, 93 (Fed.Cir.1985) (Generally, particular limitations or embodiments appearing in the specification will not be read into the claims.), overruled on other grounds by Nobelpharma AB v. Implant Innovations, Inc., 141 F.3d 1059, 46 USPQ2d 1097 (Fed.Cir.1998). For example, if an invention is disclosed in the written description in only one exemplary form or in only one embodiment, the risk of starting with the intrinsic record is that the single form or embodiment so disclosed will be read to require that the claim terms be limited to that single form or embodiment. See Teleflex, 299 F.3d at 1328, 63 USPQ2d at 1383 (To the extent that the district court construed the term `clip' to be limited to the embodiment described in the specification, rather than relying on the language of the claims, we conclude that the district court construed the claim term `clip (28)' too narrowly.); Comark Communications, Inc. v. Harris Corp., 156 F.3d 1182, 1186, 48 USPQ2d 1001, 1005 (Fed.Cir.1998) (cautioning against the limitation of the claimed invention to preferred or specific embodiments or examples); Transmatic, Inc. v. Gulton Indus., Inc., 53 F.3d 1270, 1277, 35 USPQ2d 1035, 1040-41 (Fed.Cir.1995) ([A] patent claim is not necessarily limited to a preferred embodiment disclosed in the patent.); SRI Int'l, Inc. v. Matsushita Elec. Corp., 775 F.2d 1107, 1121 n. 14, 227 USPQ 577, 585 n. 14 (Fed.Cir.1985) ( en banc ) (That a specification describes only one embodiment does not require that each claim be limited to that one embodiment.). Indeed, one can easily be misled to believe that this is precisely what our precedent requires when it informs that disputed claim terms should be construed in light of the intrinsic record. See, e.g., Markman v. Westview Instruments, Inc., 52 F.3d 967, 980, 34 USPQ2d 1321, 1329-30 (Fed.Cir.1995) (stating the claims must be construed in light of the specification and the patent's prosecution history, if in evidence). But if the meaning of the words themselves would not have been understood to persons of skill in the art to be limited only to the examples or embodiments described in the specification, reading the words in such a confined way would mandate the wrong result and would violate our proscription of not reading limitations from the specification into the claims. See, e.g., Teleflex, 299 F.3d at 1328, 63 USPQ2d at 1383; Generation II Orthotics, 263 F.3d at 1367, 59 USPQ2d at 1928; Comark, 156 F.3d at 1186, 48 USPQ2d at 1005; Transmatic, 53 F.3d at 1277, 35 USPQ2d at 1040-41; SRI Int'l, 775 F.2d at 1121 n. 14, 227 USPQ at 585 n. 14. 38 By examining relevant dictionaries, encyclopedias and treatises to ascertain possible meanings that would have been attributed to the words of the claims by those skilled in the art, and by further utilizing the intrinsic record to select from those possible meanings the one or ones most consistent with the use of the words by the inventor, the full breadth of the limitations intended by the inventor will be more accurately determined and the improper importation of unintended limitations from the written description into the claims will be more easily avoided. 39
40 Each of the asserted claims of TDS's '481 and '561 patents includes the limitation, repeatedly substantially simultaneously activating. 1 The district court construed this limitation as follows: 41 The term repeatedly means repeating in its ordinary sense, and that the repetitions be fast enough such that the composite color is actually perceived by the viewer. The term substantially, simultaneously activating means that during some portion of this period (defined as repeatedly), the two separate lights are on at the same time. 42 Tex. Digital Sys. Inc. v. Telegenix, Inc., No. 3:98-CV-1537-BF, slip op. at 11, 2000 WL 1801849 (N.D.Tex. Dec. 6, 2000). 43 Telegenix argues that the district court erred by requiring merely that the lights be on simultaneously, instead of requiring that the activation of each light begin at substantially the same time. According to Telegenix, the district court improperly separated the adverbs substantially simultaneously from the verb it modifies, activating, and thereby failed to require that the light emitting diodes (LEDs) must be activated, or turned on, at the same time. 44 According to TDS, the crucial word in the phrase is repeatedly, which would signal to one of skill in the art that the invention activates light sources repeatedly within the refreshing period or repetition period within which humans do not detect pulses due to the principle of persistence of vision. TDS argues that because one of skill in the art would understand that the claim refers to simultaneously activating light sources of different colors at some time during that critical repetition/refreshing period, and because humans cannot detect changes, pulses, or activations that occur within that period, the question of whether one begins activation of the LEDs at the exact same time or whether one simply ensures that both of the LEDs are on at some time during the repetition period is irrelevant. Thus, according to TDS, one of skill in the art would not interpret the claim term repeatedly substantially simultaneously activating the light sources to limit the starting point of the LED activations. 45 The district court correctly construed the term repeatedly. However, the district court's construction of the overall phrase repeatedly substantially simultaneously activating was in error and ignored the meaning of the term activating. We begin by ascertaining the ordinary meaning to one skilled in the art. See Specialty Composites, 845 F.2d at 986, 6 USPQ2d at 1604. According to a relevant technical dictionary, to activate is [t]o start an operation, usually by application of an appropriate enabling signal. Modern Dictionary of Electronics 20 (6th ed.1984). We presume that the word used in a claim carries this ordinary meaning, but this presumption may be rebutted. See CCS Fitness, 288 F.3d at 1366, 62 USPQ2d at 1662. Here, the intrinsic evidence is entirely consistent with the dictionary definition, and there is nothing in the record to suggest that activating means other than what its dictionary definition would suggest, i.e., starting the operation or turning on. We conclude that the presumption has not been rebutted, and thus the ordinary meaning controls. 46 TDS has argued that activating can mean being on. Certainly, once activated, a lamp might accurately be described as being on. But the claim does not refer to the state of the lamps as being substantially simultaneously activated. The words used, which serve as the focus of the claim construction analysis, call for substantially simultaneously activating the lamps, and the ordinary meaning of that phrase requires that during some portion of the period defined as repeatedly, the two separate lights are turned on at the same or nearly the same time. 47
48 Claims 1 and 3 of both the '481 and '561 patents include the limitation selectively controlling the durations of time intervals of activation. In its Markman ruling, the district court explicitly refused to provide a distinct definition for this limitation, deeming the phrase sufficiently defined. 49 Telegenix contended before the district court, and reiterates on appeal, that this limitation means specifically controlling the length of time that individual pulses are activated to vary the amount of light emitted from a light source. Telegenix argues that by his disclosure in the specification, the inventor limited the claims to varying color using pulse width modulation (PWM), a technique that varies the duration of individual pulses. Telegenix further contends that the inventor limited the asserted claims to PWM by statements and amendments during prosecution of the patents in suit. 50 TDS responds that the claims are not limited to the particular PWM technique suggested by Telegenix. TDS urges that the claim language uses the plural form of both durations and time intervals and thus is consistent with an interpretation in which color is controlled with more than one pulse and includes multiple activations of the same LED within the repetition period. In other words, TDS urges a claim construction that would cover devices which change perceived light intensity by varying either the width of the pulses or the number of pulses. 51 The words of the claim require controlling the durations of the time intervals of activation. The plain meaning of controlling the durations indicates that the claimed invention requires variation of the duration of individual time intervals, or controlling the width of pulses, during which the LEDs are activated, e.g., PWM. This plain meaning is consistent with the specification of the '481 and '561 patents. The structures shown in Figures 9 and 11 of the '481 patent and Figure 1 of the '561 patent depict circuitry for driving the LEDs using PWM. As shown in Figure 9 of the '481 patent, the circuitry includes at least one counter 71f for each color connected to a corresponding memory 76 containing data regarding the amount of primary color activation required to produce the desired color. '481 patent, col. 4, ll. 24-59. The counter and corresponding memory are connected to a flip-flop 73 which provides the appropriate output to generate the desired color. Id. According to the specification, the output of the flip flop 73 will be at a high logic level for a period of time proportional to the data loaded into the counter 71f from the memory 76. Id. at col. 4, ll. 51-52. Thus, the circuitry controls color by setting the output at a high logic level for a period of time proportional to the desired color data. 52 Moreover, the prosecution history is consistent with this interpretation of the claim language. During prosecution of the '481 patent, the inventor distinguished prior art on the basis of PWM. The Patent Office initially rejected all claims in the application as obvious in view of the Kaelin reference, which taught that LED color display elements can be varied by applying variable timed pulses to the individual diodes. The applicant responded by submitting new claims and arguing that the invention control[s] the durations of the pulses that are applied to the primary color light sources in the selected display areas to control the portions of the primary color light signals, to thereby control the color of the exhibited display unit. 53 On the basis of our review of the ordinary meaning of the words themselves, we conclude that this limitation requires control of pulse width. This is entirely consistent with the intrinsic record. Contrary to TDS's argument, introducing multiple pulses of identical duration during the repetition period does not effect control of pulse duration. Where multiple pulses of identical duration are introduced during a single repetition period, pulse duration remains constant and color is controlled not by varying the durations of the time intervals of activation of pulses, as called for in the claims themselves, but by varying the number of constant duration pulses applied. Such a technique does not set the output at a high logic level for a period of time proportional to the desired color data nor does it control the durations of the pulses, and thus is inconsistent with the specification and prosecution history. 54 We conclude that selectively controlling the durations of the time intervals of activation means controlling the width of pulses during repetition periods. 55
56 The color control means limitation appears in claims 2, 4, and 7 of the '481 patent, and claims 2 and 4 of the '561 patent. The limitation appearing in claim 2 of the '481 patent is representative: color control means for selectively controlling the durations of the pulses applied to the light sources in the selected display areas to control the portions of the primary color light signals emitted therefrom, to thereby control the color of the exhibited display unit. 57 '481 patent, col. 9, ll. 59-64. The district court construed this limitation to be a means-plus-function limitation — a conclusion with which we agree. Neither party disputes that this limitation is subject to 35 U.S.C. § 112, paragraph six. That paragraph states: 58 An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof. 59 35 U.S.C. § 112, para. 6 (2000). 60 Because this limitation is expressed in `means plus function' language and because it does not recite definite structure in support of its function, it is subject to the requirements of 35 U.S.C. § 112, ¶ 6 (1994). B. Braun Med., Inc. v. Abbott Labs., 124 F.3d 1419, 1424, 43 USPQ2d 1896, 1899 (Fed.Cir.1997). The first step in construing such a limitation is to identify the function of the means-plus-function limitation. Micro Chem., Inc. v. Great Plains Chem. Co., 194 F.3d 1250, 1258, 52 USPQ2d 1258, 1263 (Fed.Cir.1999). The next step is to identify the corresponding structure in the written description necessary to perform that function. Id. Structure disclosed in the specification is `corresponding' structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim. Braun, 124 F.3d at 1424, 43 USPQ2d at 1900. 61 The district court instructed the jury concerning the claimed function: 62 The color control means performs the function of selectively controlling the on times of the light sources to control the portions of primary color light signals for controlling the color of the composite light signal. 63 The district court described the corresponding structure from the specification as the structure that performs as disclosed in the specification of the display decoder and decoder driver. 64 Telegenix argues that the district court erred by misidentifying both the claimed function and the corresponding structure from the specification. We agree. The function recited in the asserted claims does not include selectively controlling the on times of the light sources. Instead, the claim recites selectively controlling the durations of the pulses applied to the light sources.... To the extent that the district court failed to follow the claim language in defining the function, it erred. See Micro Chem., 194 F.3d at 1258, 52 USPQ2d at 1263 (The statute does not permit limitation of a means-plus-function claim by adopting a function different from that explicitly recited in the claim.). 65 The district court further erred in its identification of the display decoder and decoder driver as the corresponding structure in the specification. 66 Section 112, ¶ 6, as is well-documented, was intended to permit use of means expressions without recitation of all the possible means that might be used in a claimed apparatus.... The price that must be paid for use of that convenience is limitation of the claim to the means specified in the written description and equivalents thereof. 67 O.I. Corp. v. Tekmar Co., 115 F.3d 1576, 1583, 42 USPQ2d 1777, 1782 (Fed.Cir.1997) (citations omitted). The duty to link or associate structure in the specification to the recited function is the quid pro quo for the convenience of employing § 112, paragraph 6. Braun, 124 F.3d at 1424, 43 USPQ2d at 1899. In the specification, the structure linked to the recited function of selectively controlling the durations of the pulses applied to the light sources includes the memory and counter circuitry illustrated in Figure 9. See '481 patent, col. 4, ll. 24-59. It was error for the district court to omit this structure from its claim construction of the color control means. 68 Accordingly, we conclude that the color control means performs the function of selectively controlling the durations of the pulses applied to the light sources to control the portions of the primary color light signals, to thereby control the color of the exhibited display unit. Moreover, we hold that the corresponding structure includes the memory 76, the counters 71e and 71f, the flip-flop 73, and associated connection circuitry illustrated in Figures 5 and 9. The color control means is limited to this corresponding structure and equivalents thereof. 69
70 The patents in suit recite display areas and background area at several locations in the asserted claims. For example, claim 1 of the '619 patent recites a plurality of variable color display areas...; [and] a variable color background area.... The district court instructed the jury: 71 Display areas and the background areas include any illuminated pixel anywhere on the display device with background pixels illuminated to substantially surround the illuminated display area pixels. As the image for illuminated display area changes, so does the adjacent illuminated background area.  72 Telegenix argues that the jury should have been instructed that the display areas are distinct from the background areas, that display areas cannot become background areas, and that background areas cannot become display areas. TDS argues that the claims encompass display areas arranged in the form of an array or matrix of areas, and as such the display areas and background areas are interchangeable. 73 Beginning with the words of the claims themselves, the dictionary meaning of display is [a] visually observable presentation of information.... Illustrated Dictionary of Electronics 147 (3rd ed.1985). Background is defined as: [the] context or supporting area of a picture.... Id. at 43. Thus, the ordinary meaning of display area, as reflected in these dictionary definitions, is an area designated to portray information. Background is ordinarily understood to provide the context or contrasting reference against which the displayed information is presented. The ordinary meaning of these limitations does not indicate that the display and background areas are interchangeable. 74 The specification of the '619 patent is consistent with an interpretation in which the display and background areas are distinct and not interchangeable. For example, the written description describes the invention as including a variable color display area and a variable color background area 32, substantially surrounding the display area. '619 patent, col. 2, ll. 16-21. The specifications of the patents in suit do not establish that display areas can become background areas, nor do they allow for their interchangeable use. 75 The specification of the '890 patent describes illuminating selected display areas in the background color to blend with the background to provide maximum color contrast. '890 patent, col. 2, ll. 41-54. However, this establishes only that the inventor contemplated that display areas could function similar to the background areas, not that the display and background areas could be interchangeable. 76 Looking to the prosecution history, there is additional evidence supporting a construction that the display and background areas are mutually exclusive. The inventor stated in response to a rejection: [claims 1 and 2], similar to claim 13 which was not explicitly rejected, are distinguished from the prior art by the recitation of background regions separated from the display areas by opaque walls. No reference of the record describes explicitly defined background regions. This evidence of manifest exclusion or restriction represents a clear disavowal of claim scope. See Teleflex, 299 F.3d at 1325, 63 USPQ2d at 1381. In doing so, the patentee expressly limited background areas to explicitly defined regions. In addition, the patent examiner stated in his notice of allowance, [t]he prior art does not show the combination of variable color display areas and a variable color background area; these being two discrete, distinct components of the device. It is this distinction which, as claimed, is deemed allowable over the prior art. 77 The ordinary meaning of the words of the claims, coupled with the patentee's statements in the specification and during prosecution, establish that the district court's instruction was in error. Although the specification indicates that a display area can be illuminated in the background color to blend with the background to provide maximum color contrast, there is no corresponding indication that the background areas can be illuminated in the display color. The district court's construction that background areas can include any illuminated pixel anywhere on the display device is incompatible with the patentee's statements during prosecution expressly limiting the background areas to explicitly defined background regions. 78 Moreover, if the background and display areas could each include any illuminated pixel, the background area would not be different in nature or quality from the display area. Such a proposition is inconsistent with the language of the claims, in which the inventor claimed a device having two types of areas, and with the specification which describes distinct display areas and background areas. 79 On the basis of the ordinary meaning of the words of the claim and the intrinsic evidence, we conclude that these limitations should be construed as follows: display areas include any illuminated pixel anywhere on the display device, other than background area pixels in defined background regions. The background area pixels substantially surround the illuminated display area pixels. Display area pixels may be illuminated in the background color, but background area pixels may not be illuminated in the display color. 80
81 The limitation display areas arranged in a pattern appears in the asserted claims of the '481 and '619 patents, as well as claim 4 of the '890 patent. The district court construed pattern to mean having a systematic arrangement. Telegenix argues that this construction is too general, and the limitation should be limited to a seven-segment display pattern, for example, that shown in Figures 1a-c of the '890 patent. TDS responds that this limitation is not limited to a seven-segment display or any other fixed pattern, and that the scope of the claims is broad enough to encompass a matrix display. 82 Where pattern is described in the specifications of the patents in suit, the seven-segment display is listed as an example of the preferred font. The '481 patent specification describes seven elongated display segments a, b, c, d, e, f, g, arranged in a conventional pattern. '481 patent, col. 2, ll. 24-25. The preferred embodiment of the '890 patent is described as including a variable color display area consisting of seven segments 31 arranged in a well known 7-segment font. '890 patent, col. 2, ll. 16-18. Nowhere in the specification is the limitation display areas arranged in a pattern restricted, explicitly or implicitly, to the seven-segment arrangement of the preferred embodiment. 83 Telegenix does not dispute that the patents in suit describe the seven-segment pattern in exemplary language. Instead, Telegenix argues that U.S. Patent No. 4,086,514 ('514 patent) establishes that the same inventor represented matrix displays and seven-segment displays as two separate embodiments of the same invention. We fail to understand the relevance of Telegenix's argument. Whether or not the claims in an unrelated patent are broad enough to encompass both a matrix and the familiar seven-segment pattern, this proposition sheds no light on whether the claims of the patents in suit are limited to the seven-segment pattern. See Abbott Labs. v. Dey, L.P., 287 F.3d 1097, 1104, 62 USPQ2d 1545, 1550 (Fed.Cir.2002) (finding the relationship between two unrelated patents, although having common subject matter, a common inventor, and the same assignee, insufficient to render particular arguments made during prosecution of [one of the patents] equally applicable to the claims of [the other patent]). 84 Referring to the prosecution history, the Examiner's Statement of Reasons for Allowance for the '619 patent stated, In this manner, multicolored arrays (i.e., color cathode ray tube displays such as Takeda, of record) in which there is no physical distinction between a foreground or background pixel (display area), are distinguished from by the claimed subject matter. Although the prosecution history may help define the scope of a term if relevant, see Southwall Techs., Inc. v. Cardinal IG Co., 54 F.3d 1570, 1576, 34 USPQ2d 1673, 1676 (Fed.Cir.1995), this Examiner's statement has no bearing on the meaning of the term pattern. Nor does this statement limit the scope of pattern to the familiar seven-segment font. 85 Accordingly, because there is nothing in the claims or the intrinsic evidence of record to indicate otherwise, we conclude that this limitation was correctly construed by the district court according to the ordinary meaning of pattern. The district court's construction, having a systematic arrangement, is not in error. 86
87 The limitation means for selectively activating said display light sources appears in claim 1 of the '619 patent. The district court instructed the jury: 88 The function of this means-plus function element is to control the activation of light sources to illuminate the display area in a first color and the background area in a second color, different from the display area's first color. The function is to activate the display area by passing current through selected light sources of the display area and the background area. The structural components are specified in Figures 3 and 4. 89 Telegenix argues that the court's construction is too broad, and misled the jury to believe that this limitation can be met by any structure broadly suggested by Figure 3, which shows only a block diagram. Telegenix requested an instruction limiting the structure to the circuitry shown in Figure 4. Telegenix also argues that passing current through selected light sources incorrectly identifies the function. 90 TDS argues that its expert testified that means for selectively activating includes hardware, software, and/or firmware for passing current through selected light sources, as supported by Figures 3 and 4. TDS argues that a block diagram such as that shown in Figure 3 may describe structure. 91 TDS argues in favor of a broad interpretation of this claim limitation in reliance on the testimony of its expert. [E]xtrinsic 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. Vitronics, 90 F.3d at 1584, 39 USPQ2d at 1578. Where the patent documents are unambiguous, expert testimony regarding the meaning of a claim is entitled to no weight. Id. `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.' Id. (quoting Southwall Techs., 54 F.3d at 1578, 34 USPQ2d at 1678-79). Thus, where the patent documents are unambiguous, reliance upon the testimony of TDS's expert witness would be improper. 92 We hold, and the parties do not dispute, that this limitation is in means-plus-function form and thus is subject to 35 U.S.C. § 112, paragraph six. As stated above, in construing such a limitation, the task of the district court is first to identify the function recited for the limitation and next to identify the corresponding structure in the written description necessary to perform that function. See Micro Chem., 194 F.3d at 1258, 52 USPQ2d at 1263. 93 The district court misidentified the recited function by including in the construction, The function is to activate the display area by passing current through selected light sources of the display area and the background area. This reference to passing current has no basis in the claim language. See Generation II Orthotics, 263 F.3d at 1364-65, 59 USPQ2d at 1926 (When construing the functional statement in a means-plus-function limitation, we must take great care not to impermissibly limit the function by adopting a function different from that explicitly recited in the claim.); Micro Chem., 194 F.3d at 1258, 52 USPQ2d at 1263 (The statute does not permit limitation of a means-plus-function claim by adopting a function different from that explicitly recited in the claim.). 94 Likewise, the district court's identification of the corresponding structure was incomplete. The description in the specification of the structure corresponding to the recited function is not limited to Figures 3 and 4, as instructed, but also includes the written description accompanying these Figures. See '619 patent, col. 3, ll. 34-68, and col. 4, ll. 1-61. Moreover, as Figure 3 and its accompanying text serve merely as overview for introducing and explaining Figure 4, the corresponding structures must necessarily be found in Figure 4. 95 We conclude that the means for selectively activating performs the function of illuminat[ing] certain of said display areas in a first color, and said background light sources, to illuminate said background regions in a second color different from said first color. The corresponding structure in the specification is described in Figure 4 and the accompanying written description, including the overview provided by Figure 3 and the written description accompanying that Figure. The means for selectively activating is limited to this corresponding structure and equivalents thereof. 96
97 The phrase converter means is a limitation recited in claim 4 of the '890 patent. The district court interpreted this phrase to mean: 98 The converter means includes firmware, software and/or hardware that functions to convert said display color control signals to obtain complementary color control signals. 99 Telegenix argues that this interpretation is unsupported, because no software or firmware is mentioned anywhere in the specification. Telegenix argues that the structure disclosed for the converter means is the multiplexer and inverter arrangement described in the written description and figures. 100 TDS argues that its expert testified that one of ordinary skill in the art would have appreciated that the converter means could be implemented in hardware, software, and/or firmware. TDS argues that the function of the converter means includes providing a complementary color in response to the selected display area color, and the multiplexer does not perform this function. Instead, according to TDS, only the inverter performs this function. 101 There is no dispute that converter means is a means-plus-function limitation within the meaning of section 112, paragraph 6. Again, in construing such a limitation, the task of the district court is to first identify the function recited for the limitation, and next to identify the corresponding structure in the written description necessary to perform that function. See Micro Chem., 194 F.3d at 1258, 52 USPQ2d at 1263. 102 In its construction of the converter means, the district court failed to identify the corresponding structure from the specification. The district court correctly performed the first step by identifying the claimed function, to convert said display control color signals to obtain complementary color control signals. However, the court's description of the corresponding structure as includ[ing] firmware, software and/or hardware has no basis in the specification. TDS essentially admits in its brief that the testimony of TDS's expert was used to broaden the court's view of the corresponding structure beyond that disclosed in the specification and prosecution history. 103 TDS argues that the structure identified by the district court could qualify as equivalent structure under section 112, paragraph six. This argument misunderstands the deficiency in the district court's construction. Even if software and firmware could be equivalent structures under section 112, paragraph six, the court failed to correctly perform the second step of identifying the structure disclosed in the written description as corresponding to the recited function. Instead, the court identified a broad array of possible structures not mentioned anywhere in the specification. 104 We conclude that the district court erred in construing this limitation. Where the patent documents are unambiguous, expert testimony regarding the meaning of a claim is entitled to no weight. Vitronics, 90 F.3d at 1584, 39 USPQ2d at 1578. The converter means performs the function of converting the display color control signals to obtain complementary color control signals. The corresponding structure includes inverters 26a-c depicted in Fig. 3 and described in the specification at col. 3, ll. 31-39, and col. 4, ll. 8-27. The converter means is limited to this corresponding structure and equivalents thereof. 105
106 The first means and second means are limitations recited in claim 4 of the '890 patent. The district court instructed the jury: 107 The first means for carrying includes functions that are performed by electrical paths which are non-inverting buses for the red and green LEDs shown in Figure 3 and described in Column 3, lines 23-30. First means includes firmware, software and/or hardware that function to carry the information which determines the display area (character) color. The court further instructed: 108 The second means for carrying includes functions that are performed by electrical paths which are inverting buses for the red and green LEDs shown in Figure 3 and described in column 3, lines 31-35. Second means for carrying includes any firmware, software and/or hardware that function to carry complementary control signals. 109 Telegenix repeats its arguments that the specification does not disclose firmware, software, and/or hardware that performs the claimed functions. Telegenix argues that the structure should be limited to inverting and non-inverting electrical buses. 110 TDS argues that Figure 2 shows structure for carrying the color control signals in the form of signal lines connecting the Display Color Control block 21 and the Complement Color Control block 22 with the Variable Color Display block 11. 111 Again, the parties do not dispute that the first means and second means are in means-plus-function form and thus are subject to 35 U.S.C. § 112, paragraph six. 112 The district court misidentified both the recited function and the corresponding structure with respect to first means and second means. Instead of identifying the function recited for the first means, the district court's instruction to the jury indicated that the function was to carry the information which determines the display area (character) color. We disagree. This language appears nowhere in claim 4, and unnecessarily limits the function actually recited in claim 4, carrying selective display color control signals. See Generation II Orthotics, 263 F.3d at 1364-65, 59 USPQ2d at 1926 (When construing the functional statement in a means-plus-function limitation, we must take great care not to impermissibly limit the function by adopting a function different from that explicitly recited in the claim.). Likewise, the district court erred in identifying the recited function of the second means. The recited function is for carrying said complementary color control signals. 113 Concerning the district court's identification of corresponding structure, it is undisputed that such structure includes the non-inverting buses described in the specification. However, the district court ventures beyond the specification to include in its construction any firmware, software and/or hardware that performs the identified function. Committing the same error as with the converter means, the district court relied on expert testimony to broaden its interpretation of the corresponding structure beyond that appearing in the specification. 114 Although TDS argues that Figure 2 identifies structure broader than the inverting and non-inverting buses described in the written description, Figure 2 fails to describe any structure for the first and second means sufficient to comport with section 112, paragraph six. If a patentee fails to disclose an adequate corresponding structure in the specification, the patentee may fail to satisfy the bargain embodied in the statutory quid pro quo of section 112, paragraph six. See Kemco Sales, Inc. v. Control Papers Co., 208 F.3d 1352, 1360, 54 USPQ2d 1308, 1313 (Fed.Cir.2000). Notwithstanding its adequacy, Figure 2 provides no support whatsoever for the district court's identification of the corresponding structure as including any firmware, software and/or hardware. 115 We conclude that the district court's claim construction for first means and second means was flawed to the extent that it misidentified the functions recited in claim 4 of the '890 patent and included in the corresponding structure any firmware, software and/or hardware. See Vitronics, 90 F.3d at 1585, 39 USPQ2d at 1579 (Because the specification clearly and unambiguously defined the disputed term in the claim, reliance on this extrinsic evidence was unnecessary and, hence, legally incorrect.). The recited function of the first means is carrying selective display color control signals, and the corresponding structure includes electrical paths which are non-inverting buses for the red and green LEDs shown in Figure 3 and described in Column 3, lines 23-30. The recited function of the second means is carrying said complementary color control signals, and the corresponding structure includes electrical paths which are inverting buses for the red and green LEDs shown in Figure 3 and described in column 3, lines 31-35. The first means and second means are limited to the identified corresponding structure and equivalents thereof. 116