Full opinion text
DECISION AND ORDER OPINION AND ORDER FOLLOWING MARKMAN HEARING MCMAHON, District Judge. On December 13, 2000, British Telecommunications (“BT”) filed suit against Prodigy Communications Corporation (“Prodigy”) for infringement of the Sargent patent, U.S. Patent No. 4,873,662 (issued October 10, 1989) (“the ’662 patent”). Prodigy answered, asserting the defenses of non-infringement and invalidity. BT reduced the number of asserted claims from seven to five on June 22, 2001, and then from five to four on January 18, 2002. BT continues to assert independent claims 3 and 5 and dependent claims 6 and 7 of the ’662 patent against Prodigy. Infringement analysis involves two phases. The proper construction of the disputed claims is determined in the first phase (the Markman phase) as a matter of law. In the second phase, issues of validity and infringement are determined as a matter of fact. Markman v. Westview Instruments, Inc., 52 F.3d 967, 976 (Fed.Cir.1995). The parties exchanged proposed constructions for the patent claim terms to be interpreted, and a hearing was conducted by the Court on February 11, 2002, limited to issues of intrinsic evidence. This decision construes the disputed claims. 1. Background of the Sargent Patent The original Sargent patent application, #814,922, was filed July 12, 1977. The Sargent invention resulted from research conducted at BT (then part of the Post Office, the provider of telephone service in the United Kingdom) on ‘videotex,’ a system developed in the early 1970s to provide users access to text-based information via a telephone network. (BT Br. at 1.) The prosecution history of the Sargent patent extended over 13 years. It includes several successor patent applications, each with multiple claims. In order to aid recognition of the documents, a brief summary follows. Application # 178,307 was filed August 15, 1980 as a continuation of the original application, #814,922, and #814,922 was abandoned. # 178,307 (“ the ’307 application”) was modified several times and by January 26, 1983 claims 1-18 had been canceled, leaving claims 19-22 before the patent examiner. On June 8, 1983, # 502,-114 (“the T14 application”) was filed as a divisional application of ’307, directed to the subject matter of the claims originally filed in application ’307 as claims 7-9. Amendments to T14 canceled 7-9 in favor of 12-15, and then claim 14 was canceled, leaving three claims. After the examiner issued a final rejection to both applications, the applicant appealed to the U.S. Patent Board of Appeals, which heard the appeals together on November 7, 1988. The Board reversed and the Sargent patent was granted on October 10, 1989. In the patent as issued, application ’307 claims 19-22 became patent claims 1-4, and application T14 claims 12, 13 and 15 became patent claims 5-7, of #4,873,662 (“the ’662 patent”). The Sargent patent describes an improved way for multiple users, each located at a remote terminal, to access data stored on a central computer. Communication between the remote terminals and the central computer takes place over a telephone network. (See BT Br. at 2-3.) The information accessed by the remote terminals is stored on the central computer in the form of blocks, each block identified by an address. The central computer uses the address to retrieve the associated block from storage when a user requests that block of information. Each block stored on the central computer is comprised of two parts: a first portion, which contains textual and graphical data for display (a display page), and a second portion, not intended for display, which contains the complete addresses of other blocks of information that are linked to the current display page. (Id. at 2.) In the asserted claims, the entire block is transmitted to the remote terminal where the first portion is displayed and the second portion is stored in the local memory of the remote terminal. The display page includes abbreviated addresses of particular blocks of information that can be accessed from the central computer. When the user selects one of the displayed abbreviated addresses, the terminal accesses its memory to determine the corresponding complete address. That complete address is then sent to the central computer to request the next desired block of information. (Id. at 1-3.) BT’s description of the patent infers that the abbreviated address is the invention, (BT Br. at 2 (last sentence)), but the applicant acknowledged that use of an abbreviated address was recognized in the prior art. (Jan. 24, 1986 Appeal Br., Prodigy Br. Ex. 3 at 2; Jan. 6, 1987 Appeal Br., Prodigy Br. Ex. 14 at 2.) The innovation claimed by the Sargent invention is instead how the blocks of information are stored: Ordinarily one would be inclined to astutely avoid storage of the address-linkage data on the disk store — where data access times are relatively long and where there necessarily must be competition for data accesses to obtain the display data itself. One typically seeks to reduce required accesses to the disk store. Nevertheless, applicant teaches: (a) dividing up the total address linkage data array into sub-portions associated only with the possible next screen selections to be made from a given screen; (b) co-storing such sub-portions on the main store (e.g., a disk) contiguous with the said “given” screen data; and (c)only temporarily stripping off and storing in RAM those sub-portions which are associated with the screen then actively being accessed and viewed within the system. (Jan. 24,1986 Appeal Br. at 3; Jan. 5,1987 Appeal Br. at 3.) The applicant clarified that the “object of this invention ... is to enable the computer to service as many requests for data as possible with a given maximum delay time[.]” (Jan. 24, 1986 Appeal Br. at 10; Jan. 5, 1987 Appeal Br. at 16.) “[Thus the] invention overcomes a very real difficulty in the art of distributed digital information storage, retrieval and display.” (Jan. 24, 1986 Appeal Br. at 11; Jan. 5, 1987 Appeal Br. at 17.) 2. Claim Construction The technique for construction of a disputed claim was set forth by the Federal Circuit in the Markman decision. 52 F.3d at 976-80. The meaning of a claim should be interpreted in light of the intrinsic evidence, comprised of the claims and the specification of the patent, and the prosecution history. Id. at 979. The intrinsic evidence constitutes the public record of the patent on which the public is entitled to rely. Id. Thus, if the intrinsic evidence is sufficient to resolve the meaning of a disputed term, then it is improper to resort to extrinsic evidence such as expert testimony or treatises. Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1583 (Fed.Cir.1996). Extrinsic evidence only should be relied upon where necessary to resolve an ambiguity in a disputed claim term. CVI/Beta Ventures, Inc. v. Tura, L.P., 112 F.3d 1146, 1153 (Fed.Cir.1997). To define the scope of the patented invention, the Court must first look at the words of the claims themselves. Vitronics Corp., 90 F.3d at 1582 (citing Bell Communications Research, Inc. v. Vitalink Communications Corp., 55 F.3d 615, 620 (Fed.Cir.1995)). Words in the claim are generally given their ordinary and customary meaning. However, “a pat-entee may choose to be his own lexicographer” and assign special definitions to the words in the claim, as long as those definitions are clearly stated in the patent specification or file history. Id. (citing Hoechst Celanese Corp. v. BP Chems. Ltd., 78 F.3d 1575, 1578 (Fed.Cir.1996)). Therefore, “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.” Id. (citing Markman, 52 F.3d at 979). The Federal Circuit has stated that “claims must be read in view of the specification, of which they are a part.” Id. (citing Markman, 52 F.3d at 979); see also Gart v. Logitech, Inc., 254 F.3d 1334, 1341 (Fed.Cir.2001) (“it is certainly correct that the specification and the prosecution history should be consulted to construe the language of the claims.”). Because the specification must contain a description sufficient to enable those of ordinary skill in the art to make and use the invention, the specification “is the single best guide to the meaning of a disputed claim term.” Id. The court also may consider the prosecution history of the patent. Id. (citing Markman, at 980; Graham v. John Deere, 383 U.S. 1, 33, 86 S.Ct. 684, 15 L.Ed.2d 545 (1966)). The prosecution history is the complete record of the proceedings before the Patent and Trademark Office. During the course of these proceedings, the applicant may have made express representations regarding the scope of the invention, so the prosecution history is “often of critical significance to determining the meaning of the claims.” Id. (citing Markman, 52 F.3d at 980; Southwall Tech., Inc. v. Cardinal IG Co., 54 F.3d 1570, 1576 (Fed.Cir.1995)). Claim terms may appear to be plain language— as in this case, where most of the words have fairly straightforward definitions, or have passed over time into common usage. However, the prosecution history may demonstrate that the claims do not cover some matters that would otherwise be encompassed in the plain meaning of the words used. Prosecution histories often contain an analysis of the distinctions between the prior art and the applicant’s claims, providing the Court with clues to limitations of the claims. Id. at 1583; Autogiro Co. of America v. United States, 181 Ct.Cl. 55, 384 F.2d 391, 399 (1967). Furthermore, “the prosecution history limits the interpretation of claim terms so as to exclude any interpretation that was disclaimed during prosecution.” Southwall Tech., Inc., 54 F.3d at 1576. Even when the written description would otherwise support a construction, the prosecution history, which is generated after-wards, can relinquish any coverage of that claimed embodiment. Rheox, Inc. v. Entact, 276 F.3d 1319, 1325-27 (Fed.Cir.2002). Prodigy’s claim construction arguments are primarily based on relinquishments allegedly made during the prosecution of the Sargent patent. 3. Means-Plus-Function A means-plus-function element under 35 U.S.C. § 112, ¶ 6 is one that refers to a “means” for performing a given function, without specifying in the claim the structure for performing that function. Chiuminatta Concrete Concepts, Inc. v. Cardinal Indus. Inc., 145 F.3d 1303, 1307-08 (Fed.Cir.1998). The applicant is presumed to have used the word ‘means’ in a claim to state a means-plus-function limitation under 35 U.S.C. § 112, ¶ 6. York Prods., Inc. v. Central Tractor Farm & Family Ctr. and Custom Form Mfg., Inc., 99 F.3d 1568, 1574 (Fed.Cir.1996). Means-plus-function elements have additional claim construction rules. 35 U.S.C. § 112, ¶ 6. In Lockheed Martin Corp. v. Space Systems/Loral, Inc., 249 F.3d 1314, 1324-25 (Fed.Cir.2001), the Federal Circuit set forth a three step process for construing the means-plus-function language. First, the court must identify the claimed function. Id. Once this function is identified, it must be construed using the ordinary principles of claim construction. Id. The function of a ‘means plus function’ claim must be construed to include the limitations contained in the claim language. Id. However, a claimed function may not be improperly narrowed or limited beyond the scope of the claim language. Id. Finally, the court must determine the corresponding structure disclosed in the patent specification for performing the function. Id.; see also Chiuminatta, 145 F.3d at 1307-08; Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 934 (Fed.Cir.1987) (en banc). Means-plus-functions limitations are construed to cover the corresponding structure described in the specification and any equivalents thereof. 35 U.S.C. § 112, ¶ 6. The structure includes any device that is identical or structurally equivalent to that structure described in the specification. Valmont Indus., Inc. v. Reinke Mfg. Co., 983 F.2d 1039, 1042-44 (Fed.Cir.1993). The structure disclosed in the patent specification must be clearly linked to the claimed function. B. Braun Medical Inc. v. Abbott Labs. and NP Medical, Inc., 124 F.3d 1419, 1424 (Fed.Cir.1997). 4. Means-Plus-Function Analysis In their briefing, the parties agreed that “central computer means” and “remote terminal means” were not means-plus-function elements, while “keypad means,” “modem means,” “display means,” “local memory means,” “further memory means,” “means coupled to said memory means and to said keypad means,” “means responsive to information stored in the further memory means,” and “logic means” were means-plus-function elements. The Court questioned how this could be so at the Mark-man hearing, and the parties analyzed the terms both ways. Claim 3 includes: a central computer means in which plural blocks of information are stored at respectively corresponding locations each of which locations is designated by a predetermined address therein by means of which a block can be selected, each of said blocks comprising a first portion containing information for display and a second portion containing information not for display but including the complete address for each of plural other blocks of information ... ’662 patent, col. 6,11. 15-24. The use of the word “means” in the claim (particularly as used in the phrase “means for”) raises a presumption that the means-plus^function limitation applies. York Prods., Inc., 99 F.3d at 1574; Greenberg v. Ethicon Endo-Surgery, Inc., 91 F.3d 1580, 1584 (Fed.Cir.1996). The means-plus-function presumption may be rebutted, however, if the claim uses the word “means” but specifies no corresponding function for the “means,” or if the claim recites a function but also includes a definite structure to perform entirely the recited function. Sage Prods., Inc. v. Devon Indus., Inc., 126 F.3d 1420, 1427-28 (Fed.Cir.1997); Cole v. Kimberly-Clark Corp., 102 F.3d 524, 531 (Fed.Cir.1996). The Court must determine, as a matter of law, whether to apply the means-plus-function analysis. Whether there is definite structure recited in the claim language may be evidenced by a lack of alternate structures disclosed in the specification. See Turbocare Division of Demag Delaval Turbomachinery Corp. v. General Electric Co., 264 F.3d 1111, 1120-21 (Fed.Cir.2001). In Turbocare, the Federal Circuit found that a claim including the term “compressed spring means” recited too much structure to be means-plus-fnnction. Id. Nothing in the specification disclosed anything other than a “spring” or a “compressed spring” to perform the function of the “compressed spring means.” Id. at 1121. This result differed from the court's prior decision in Unidynamics Corp. v. Automatic Prods. Int'l, Ltd., 157 F.3d 1311, 1319-22 (Fed.Cir.1988). In that case, the court found that the term “spring means” was written in the means-plus-function format. Id. The Federal Circuit decided that the use of the word “spring” did not preclude the means-plus-function limitation because the specification demonstrated that a “spring” was only one example of a “spring means.” Therefore, the Federal Circuit found that the phrase “spring means” was broader than a “spring” as generally recognized in the mechanical arts. See Turbocare, 264 F.3d at 1120 (distinguishing Unidynamics, 157 F.3d 1311). Accordingly, I find that the “central computer means” is not a means-plus-function claim. The functions of the central computer are stated in the claim language, however, the claim recites the entire structure necessary to perform the claimed function. Sage, 126 F.3d at 1427-28. That structure is a computer. The function of the central computer means as asserted in the claims is storing blocks of information. The computer also communicates with the remote terminals. The specification discloses a “computer” for performing these functions. The term “computer” is the only structure described in the specification, and there is no indication that the patentee wished the term “computer means” to be broader than a “computer.” If the term “computer” does not tell us what the computer is, then the claim would be indefinite. See S3 Inc. v. nVIDIA Corp., 259 F.3d 1364, 1367 (Fed.Cir.2001) (quoting In re Donaldson Co., 16 F.3d 1189, 1195 (Fed.Cir.1994) (“if an applicant fails to set forth an adequate disclosure, the applicant has in effect failed to particularly point out and distinctly claim the invention as required ... ”)). If possible, patents should be construed in order to preserve their validity. Modine Mfg. Co. v. United States Int’l Trade Comm’n, 75 F.3d 1545, 1557 (Fed.Cir.1996) (abrogated on other grounds). Therefore, I find that “central computer means” is not a means-plus-function. The same is true of the phrase “remote terminal means” found in the following claim language: plural remote terminal means, each including (a) modem means for effecting input/output digital data communications with said central computer means via the telephone lines of a telephone network, (b) local memory means for locally storing digital data representing at least the first portion of the selected block of information received via said modem means from the central computer and for processing' digital data, (c) display means for visually displaying such a locally stored first portion of a block of information and (d) keypad means connected to communicate data to at least said local memory means for manual entry of keyed digital data; and further memory means being provided as part of said local memory means at each of said remote terminal means for receiving and storing said second portion of the selected block of information in response to the selection of the block and when its respective first portion is transmitted thereto, said local memory means utilizing keyed digital data of less extent than any one of said complete addresses for. another block of information but nevertheless uniquely indicative of one of the complete addresses contained in said second portion of the block of information which contains the first portion then being displayed for selectively accessing said further memory means and for supplying data to be transmitted by said modem means and indicative of the complete address of the next block of information which is to be retrieved and utilized for display purposes. ’662 patent, col. 6, 11. 25-66. The claim language discloses the structure of the remote terminal means. It describes the component parts of a terminal. The phrase starts “plural remote terminal means, each including ...” —in other words, the remote terminals are comprised of the component parts that follow that language. The function of the remote terminal means, although it is not stated in the usual means-plus-function format, is to store, retrieve and display at a remote site digital information obtained from the computer means. The explanation of these components contains sufficient structure to perform this function. Therefore, the claim language overcomes the means-plus-function presumption. In Turbocare, the Federal Circuit found that “radial positioning means” in the following claim language was not a means-plus-function: a radial positioning means comprising a compressed spring means biased against said ring segments to forcibly cause said segments to move to said large clearance position, while working fluid which is freely admitted to the annular space between said casing and said ring segments toward said small clearance position, whereby at low speed and small turbine loads the spring forces will predominate, while at high flows and high working fluid pressure the pressure forces will predominate. 264 F.3d at 1119. The structures for performing the function of positioning the ring segments were the compressed spring means and the working fluid. Id. Similarly, in the case at hand, I find that the component parts listed in the claim language describing the remote terminal means state its structure. Unlike in Tur-bocare, I have decided that some of these component parts are means-plus-function terms. However, I do not find that this distinction makes the meaning of the remote terminal means a means-plus-function where radial positioning means was not. The structure of the component parts is present — it is just found in a different part of the patent, in the specification, rather than in the claim language. Hence, I find that the phrase “remote terminal means” is not a means-plus-function. For the same reason, I have also concluded that “modem means” is not means-plus-function terms. There is no structure disclosed in the specification for this claim term other than a “modem.” I do agree with the parties, however, that display means, keypad means, local memory means, further memory means, means coupled to said memory means and to said keypad means, means responsive to information stored in the further memory means, and logic means are all means-plus-function terms. CLAIM 3 A digital information storage, retrieval and display system comprising: a central computer means in which plural blocks of information are stored at respectively corresponding locations each of which locations is designated by a predetermined address therein by means of which a block can be selected, each of said blocks comprising a first portion containing information for display and a second portion containing information not for display but including the complete address for each of plural other blocks of information; plural remote terminal means, each including (a) modem means for effecting input/output digital data communications with said central computer means via the telephone lines of a telephone network, (b) local memory means for locally storing digital data representing at least the first portion of the selected block of information received via said modem means from the central computer and for processing digital data, (c) display means for visually displaying such a locally stored first portion of a block of information and (d) keypad means connected to communicate data to at least said local memory means for manual entry of keyed digital data; and further memory means being provided as part of said local memory means at each of said remote terminal means for receiving and storing said second portion of the selected block of information in response to the selection of the block and when its respective first portion is transmitted thereto, said local memory means utilizing keyed digital data of less extent than any one of said complete addresses for another block of information but nevertheless uniquely indicative of one of the complete addresses contained in said second portion of the block of information which contains the first portion then being displayed for selectively accessing said further memory means and for supplying data to be transmitted by said modem means and indicative of the complete address of the next block of information which is to be retrieved and utilized for display purposes. ’662 patent, col. 6,11. 13-56. A. Central Computer Means A computer is a device that receives, processes and presents data. In this patent, the computer is a single device, in one location. It is referred to as “central” because it is connected to numerous physically separate stations called, “remote terminals,” by the telephone lines of a telephone network. So there is one computer, connected to many remote terminals. The central computer means in this patent thus serves as the hub of a digital information storage, retrieval and display system — and all of the remote terminals connect to it. The central computer stores information. The central computer contains a “main store.” In the context of this patent, the main store is a mass information storage or memory device. An example of a main store is a magnetic disk, which is a rotating circular plate having a magnetizable surface on which information may be stored as a pattern of polarized spots on concentric recording tracks. Now, a magnetic disk is not the only thing that qualifies as a main store — that term also includes such things as a Cartridge Disc (which is a type of disk storage device consisting of a single disk encased in a compact container which can be inserted in and removed from the disk drive unit), a Magnetic Tape 9 track, and a paper tape recorder. But the main memory device does not include something called RAM — random access memory. RAM is a type of memory that is volatile, meaning that it loses its contents when the power is turned off. RAM cannot be used as the main store in the context of this patent. The central computer contains an information database, which is “centralized” in the sense that all of the remote users can access it by accessing the central computer. This data is stored as something the inventor called “blocks of information.” The central computer means communicates “via the telephone lines of a telephone network” with “plural remote terminal means.” The central computer means is the device “in which plural blocks of information are stored at respectively corresponding locations.” ’662 patent, col. 6,1. 15. The central computer means retrieves and sends at least a portion of the “block of information” associated with the requested “complete address” to the remote terminal from which the request originated. Id., 11. 26-28, 53-54. 1. The “central computer means” is a central computer in one location Throughout the specification, the “central computer means” is referred to as a computer, defined as “a device that receives, processes, and presents data.” Dictionary of Scientific and Technical Terms 342 (Sybil P. Parker ed., McGraw Hill 3d ed.1984). The word “central” modifies “computer” to describe the relationship between the device where the “blocks of information” are stored, and the “remote terminals” from which an operator may access the information. The term “central” therefore suggests that the computer is the hub of a “digital information storage, retrieval and display system.” This hub is in one central location, connected with many remote terminals. BT’s proposed definition (a computer system that stores and transmits blocks of information) ignores the juxtaposition emphasized by the description of a “central computer” connected via the telephone lines of a telephone network to “remote terminals.” (emphasis added). As Prodigy points out, “all the limitations of a claim must be considered meaningful,” Unique Concepts, Inc. v. Brown, 939 F.2d 1558, 1562 (Fed.Cir.1991), and no claim language may be interpreted as mere sur-plusage. Texas Instruments, Inc. v. United States Int’l Trade Comm’n, 988 F.2d 1165, 1171 (Fed.Cir.1993). BT’s definition does not make it clear that the computer means is a “central one,” and thus is incomplete. BT responds that the term “central” is conveyed by the claim language that says that the remote terminals are connected “via the telephone lines of a telephone network.” While the remote terminals are indeed connected to the central computer means via the telephone lines, this does not give meaning to the term “central” in the phrase “central computer means.” Prodigy’s definition, which clarifies that the central computer is in one location, does. According to the specification, “information is derived from a central computer at a remote point and transmitted via the public telephone network to terminal apparatus.” ’662 patent, col. 1, 11. 9-11. This indicates that there is one central computer at one point, or place. Throughout the specification, the “computer” is referred to as a singular device. The embodiments in the detailed description and diagramed by the figures are also consistent with this interpretation. While the inventor carefully describes how the computer and any remote terminal are connected (via telephone lines), the inventor never mentions connections between the parts of the “central computer means.” Therefore, I find that the specification confirms that the central computer is a single device, in one location. 2. The central computer contains a main store The “central computer means” must have a “store” for storing data. The parties dispute whether the applicant specified a particular kind of store during the patent prosecution. Several passages from the applicant’s appeal briefs discuss storage on the central computer means. The applicant’s communications with the patent office included references to a “store” (Jan. 26, 1983 Amend., Prodigy Br. Ex. 4, at 6-7), “a multi-address store” (Id. at 7), a “mass storage device” (Jan. 24, 1986 Appeal Br. at 1-2), a “central main ‘store’ or mass memory device such as a magnetic disk,” (Id. at 2), a “main store (e.g. a disk)” (Id. at 3; Jan. 5, 1987 Appeal Br., at 3), and a “main data storage device” (Jan. 24, 1986 Appeal Br. at 9). While the applicant did mention many kinds of “stores” during the course of the patent prosecution, the most compelling citation is located in two of the applicant’s appeal briefs where the applicant stated: Ordinarily one would be inclined to astutely avoid storage of the address-linking data on the disk store — where data access times are relatively long and where there necessarily must be competition for data accesses to obtain the display data itself. One typically seeks to reduce required accesses to the disk store. Nevertheless, applicant teaches: (a) Dividing up the total address linkage data array into sub-portions associated only with the possible next screen selections to be made on a given screen; (b) co-storing such sub-portions on the main store (e.g. a disk) contiguous with the said “given” screen data; and (c) only temporarily stripping off and storing in RAM those sub-portions which are associated with the screen and then actively being accessed and viewed within the system. In this manner, no extra disk access cycles are required (because the relevant co-stored address linkages are fetched at the same time a given “screen” of data is fetched)' — and yet— the majority of the massive address linkage data is, at any given time, actually stored on the mass store (e.g. the disk)! The necessary size of RAM can be maintained within reasonable limits — and yet — the relevant portion of the address linkage array is always readily at hand for substantially immediate access in RAM. (Jan. 24, 1986 Appeal Br., p. 3; Jan. 5, 1987 Appeal Br., p. 3 (italics added, underlining in original).) This reference is highly significant because it: (1) describes what the invention “teaches;” (2) distinguishes the invention over prior art with respect to the type of storage used; and (3) distinguishes between the “main store” (hard disk storage) and RAM. BT argues that this citation to the prosecution history merely discusses the advantages of the technology of the Sargent patent, rather than distinguishes prior art. BT further argues that the file wrapper describes a number of different “stores,” and Prodigy improperly attempts to narrow the claim to only one of those descriptions. However, BT is incorrect. “Teaches” is a term of art in the patent world — what the patent “teaches” is the invention. Therefore, the explanations in this passage relating to the way data is stored in the system are of particular significance. In this passage, the applicant notes that the manner of storing information is the distinction between his invention and prior art. The parties are particularly concerned about whether this passage disclaims the use of RAM as a “main store.” This quote, found in two of the applicant’s appeal briefs, supports Prodigy’s contention that RAM has been disclaimed. The briefs open by describing the prior art in the world of “data base storage and retrieval system[s].” (Jan. 24, 1986 Appeal Br. at 1; Jan. 5,1987 Appeal Br. at 2.) The applicant acknowledges that the usefulness of “abbreviated keyed-in selection data is recognized in the prior art.” (Jan. 24, 1986 Appeal Br. at 2; Jan. 6,1987 Appeal Br. at 2.) In such systems (i.e., abbreviated keyed-in selection data systems), “Then one might store the necessary full address linkage data in RAM where it is readily accessible for use in translating a user’s keyed-in single digit ... into the full disk-store address of the next desired screen.” (Jan. 24,1986 Appeal Br. at 2; Jan. 5,1987 Appeal Br. at 2.) However, this “scheme” has its disadvantages “as more voluminous and complex data bases are considered.” (Jan. 24, 1986 Appeal Br. at 2; Jan. 5, 1987 Appeal Br. at 2.) These drawbacks, as stated by the applicant, are that more RAM must be used for this function, proper updating may become complicated, and inefficient use of RAM and disk storage may result. The applicant explains that his invention flies in the face of the conventional wisdom regarding storage of the address linkage data. (Jan. 24, 1986 Appeal Br. at 3; Jan. 5, 1987 Appeal Br. at 2.) The accepted wisdom was to avoid storage on the disk store where data access times are too long. Applicant’s appeal brief argues that his invention instead creates a system where address information would indeed be stored on the disk store, but divided up in such a way that it could be quickly accessed by the user. (Jan. 24, 1986 Appeal Br. at 3; Jan. 5, 1987 Appeal Br. at 3.) The applicant also taught that the address linkage data was to be divided into sub-portions associated only with the possible next screen selections to be made. These sub-portions of data were stored on the main store and only temporarily stripped off and stored in RAM when actively accessed and viewed within the system. The applicant thus explained the genius of his invention- — -that the information is stored on the main store in the central computer means and moved to RAM only when called up by the user. In the parlance of this patent, local memory means and further memory means may be RAM, but the main store may not be. Indeed, it is integral to the invention that the main store in the central computer not be RAM. BT cannot now claim that the store on the “central computer means” includes RAM, because the applicant argued during the prosecution of the patent that his invention taught against using this storage device. The applicant states that a disk is an example of the main store. A disk is “a rotating circular plate having a magnetizable surface on which information may be stored as a pattern of polarized spots on concentric recording tracks.” Dictionary of Scientific and Technical Terms 471 (Sybil P. Parker ed., McGraw Hill 3d ed.1984). BT asserts that other examples of stores that the applicant suggested in the file wrapper are a 64KB Store Unit, Cartridge Disc (according to the technical dictionary, a type of disk storage device consisting of a single disk encased in a compact container which can be inserted in and removed from the disk drive unit, Dictionary of Scientific and Technical Terms 256 (Sybil P. Parker ed., McGraw Hill 3d ed.1984)), Magnetic Tape 9 track, and a paper tape recorder. These are all examples of nonvolatile storage, defined by the technical dictionary as “a computer storage medium that retains information in the absence of power, such as a magnetic tape, drum, or core.” Dictionary of Scientific and Technical Terms 1093 (Sybil P. Parker ed., McGraw Hill 3d ed.1984). Given that the applicant used the term “e.g.,” the Court certainly will not limit the main store to a magnetic disk and nothing else. But the fact that all of the examples listed by the applicant are types of nonvolatile storage confirms my conclusion that volatile storage, like RAM, was not within the scope of the “main store” as envisioned by the pat-entee. 3. The central computer contains a centralized information database Similarly, the applicant made several references during the patent prosecution to the “centralized informational data base,” (Mar. 28, 1985 Amend., Prodigy Br., Ex. 5 at 4-5), “centralized stored data file,” (Id.; Jan. 24, 1986 Appeal Br. at 8-9; Jan. 5, 1987 Appeal Br. at 14-15), and “large mass publicly accessed informational data base[].” (Jan. 24, 1986 Appeal Br. at 9.) These references were used to describe the “digital information storage, retrieval system the applicant was attempting to patent” — “where the sole purpose of the remote [terminals] is to provide a great number of users substantially simultaneous access to a centralized stored data file” (See e.g., Jan. 24, 1986 Appeal Br. at 8) or the “centralized informational data base.” (Id.) Therefore, BT cannot now claim that the “central computer means” does not contain a centralized information database. B. Blocks of Information Now, the central computer stores information in something called “blocks.” There are many of these blocks of information stored in the central computer. Each block has a first portion and a second portion. These portions are separable, contiguous and co-stored sub-units. That means that the portions are stored together, and they are stored next to each other, yet they can be separated from each other. A block of information may contain very limited programming information, the purpose of which is to reduce the complexity of keying required to communicate with the central computer. The two parts of a block of information are the first portion and the second portion. The first portion of a block of information is intended for visual display on a remote terminal. The second portion is information not intended for display. The second portion contains the complete address for each of the other blocks of information referenced in the first portion. So if a block of information is referenced in the first portion, then the complete address for that block of information will be in the second portion. The second portion may also contain other information as well, such as information to influence the display or to reduce the complexity of keying required to communicate with the central computer. But it never contains information intended for display. The blocks of information are stored in “respectively corresponding locations.” These are simply places on the central computer’s main store where blocks of information are stored. Each of these locations has a predetermined address — that is, an address that was determined, or set, before the data is accessed. The complete address is the entire number or name that uniquely identifies, without reference to other information, a location on the central computer’s main store where a block of data will be found. 1. Block of Information Everyone agrees that a block of information is a unit of data containing two subunits, which the inventor denominated “first portion” and “second portion.” Both parties agree that the two sub-units of data are “co-stored” — which I take to mean they are stored in conjunction with one another — although that word does not appear anywhere in the claim. And while BT does not include the word “separable” in its construction, it can have no quarrel with that concept, since the patent plainly teaches that the two portions within a data block are to be separated and stored in two different memories after they are retrieved from the central computer means. The hotly contested issue in connection with the term “block of information” concerns the concept of contiguity, to wit: whether the two portions must be stored contiguously in order to fall within the ambit of the invention. The plain language of the claim does not compel, or even suggest, such a limitation. Neither does the language of the specification. And I would not read this limitation onto the claim from the visual configuration of Fig. 2 in the specification, or from the use of the word “page” in connection with that figure. If such a limitation is to be imposed, it must follow from concessions made during patent prosecution. The prosecution history is replete with references to the contiguity between the two portions of a data block. It is seen most clearly in connection with Sargent’s two appeal briefs, which contain the following statements: Nevertheless, applicant teaches: (a) dividing up the total address linkage data array into subportions associated only with the possible next screen selections to be made from a given screen; (b) co-storing such sub-portions on the main store (e.g., a disk) contiguous with the said “given” screen data; (Jan. 24,1986 Appeal Br. at 3; Jan. 5,1987 Appeal Br. at 3. (emphasis added)) By asserting that his patent “teaches” a system that stores the hidden portions of the data block portions contiguously with the display data, applicant limits himself to contiguous storage. This conclusion is reinforced by other references in the prosecution history to contiguous storage, such as its claim amendment of June 10, 1986 (’662 File Wrapper, Tab 22 at 7), in the 1987 Appeal Brief (Jan. 5, 1987 Appeal Br. at 12-13), which states that none of the references being distinguished teaches “a system wherein each screen of displayed data is associated with its own segregated but yet contiguously located and co-stored and co-addressed index .... ” BT asserts that any notion of contiguity, as used in the prosecution history, can only be understood as referring to the data’s being “co-stored” (i.e. “stored together” or “stored in conjunction with each other”). Thus, BT asks me to read co-stored and contiguous as synonymous. However, the applicant’s filings with the Patent Office suggest otherwise. As noted above, Sargent refers to data that is “contiguously located. and co-stored and co-addressed.” (Jan. 5,1987 Appeal Br. at 12.) If contiguity and co-storing are one and the same, the connective used by Sargent would have been “or,” not “and.” I therefore find that the two sub-units of information contained in a block of data must be contiguously stored as well as co-stored (stored together). Prodigy asks me to incorporate the word “segregated” into the construction, relying on the same passage from the 1986 Amendment and the 1987 Appeal Brief, (Jan. 24,1986 Appeal Br. at 3; Jan. 5,1987 Appeal Br. at 3; File Wrapper Tab 22), to clarify that the portions may not be intermixed. While the word “segregated” does appear in the specification and the prosecution history, I am not aware of any rule of patent construction that requires me to incorporate each and every word ever used in conjunction with a patent claim in the claim construction. The parties have not suggested any meaning for “segregated” that makes it integral to the definition of the term “block of information.” The very idea of the block’s two discrete sub-parts— the first and second portions — incorporates the notion of segregation or separability, and I have already decided to include separability in the definition. It will unnecessarily confuse the jury to incorporate a second word that means much the same thing. Prodigy also asks the Court to insert a temporal limitation into the definition of block of information, namely, that the first and second portions of the block must be accessed and transferred to their respective memories simultaneously. This limitation is derived from and supported by the claim language of Claims 3 and 5, each of which provides that the second portion is to be received by and stored in the further memory means “when” the first portion is transmitted to the remote terminal for display. “When” has been defined by the Federal Circuit as “at the time of, and not some appreciable time thereafter.” Renishaw PLC v. Marposs Societa’ per Azioni, Maiyoss Corp., 158 F.3d 1243, 1252 (Fed.Cir.1998). Thus, the use of the word “when” in the claim language suggests simultaneous transfer — an inference bolstered by the prosecution history, which makes liberal use of the word “simultaneous” and its synonyms, including “jointly” and “at the same time.” (Aug. 29,1983 Amend., Prodigy Br., Ex. 6; Apr. 3, 1984 Amend., Prodigy Br., Ex. 8.) My problem is not with the limitation, but with where Prodigy seeks to place it. The temporal limitation is really part of the function for another aspect of the invention — the “further memory means.” As it fits logically into that context, and is more than a little strained as part of the definition of the block of information, I shall put it where it belongs. Finally, Prodigy asks that I decree that blocks of information as used in this patent do not encompass computer programs transmitted to the remote terminal. Prodigy does so on the basis of four virtually identical references in Applicant’s March 28, 1985 and April 3, 1986 Amendments and its January 24, 1986 and January 5, 1987 Appeal Briefs, which were inserted to distinguish the Tsuda patent. The applicant stated, for example, that: a very large amount of requested access traffic can be expected at the main computer site at any given time. Consequently, approaches like that of Tsuda et al where an entire program segment is downloaded on an ongoing basis simply would be unacceptable.... (March 28, 1985 Amend, at 7). BT responds by citing the specification, which includes that “the second part of a block of information may include software, that is programming information, for simplifying entries to be made by an operator on the basis of the information displayed to him by the terminal apparatus.” ’662, col. 2, 11. 21-24. Given that the specification states “a block of information may include software,” there must be strong proof in the file wrapper to exclude software from the “blocks of information.” See Vitronics, 90 F.3d at 1583. The prosecution history citation demonstrates that under the Sargent patent, downloading an entire program segment on an ongoing basis is not acceptable. Prodigy asks the court to construe that the second portion may never contain program information at all. Prodigy points to a March 28, 1985 amendment to the ’307 application as proof of its theory: it should be clearly recognized that the digital data being downloaded in Tsuda et al is a computer program and not mere key translation data containing the complete address for each of plural other blocks of “display” information— which can be independently and uniquely selected by the user’s keyed-in responses. (March 28, 1985 Amend, at 6.) The Tsuda invention is an educational tool that uses a computer program to respond to a user’s inputs to determine the next page to access. (BT Reply Br., Ex. L, col. 1, 1. 54— col. 2, 1.7.) Tsuda does not store together or download the linking information along with the information for display. The inputs in the Tsuda reference do not correspond to the complete address for other blocks of information — in fact, in that invention, what was called up on the screen depended on a number of factors, including the amount of time that it took for a student to answer the question. (Id.; see also March 28, 1985 Amend, at 6-7.) The kind of complicated computer program necessary in Tsuda cannot be used in the Sargent patent; the Sargent applicant limited himself to “mere key translation data.” This term suggests a simple operation, however in order to perform the translation, a limited amount of programming information may be necessary. In other words, the ’662 patent is limited to the kind of programming information disclosed in the specification — that which is used to “simplify! ] entries to be made by an operator on the basis of information displayed to him by the terminal apparatus.” ’662, col. 2, 11. 21-24; see also col. 4, 11. 25-37 (stating that one of the uses of the information in the second portion of the block of information could be “to reduce the complexity of keying required to communicate with the computer 1”). I therefore find that the block of information may only contain very limited programming information, the purpose of which is to reduce the complexity of keying required to communicate with the central computer. 2. First and Second Portions As to the first and second portions, both parties agree that these are the two subunits of a block of information; that the first portion is intended for visual display at the remote terminal; and that the second portion is not intended for visual display. They part company over Prodigy’s desire to incorporate additional limitations onto each portion’s definition. As to the first portion, I agree with BT that simpler is better; as to the second portion, I am constrained to conclude that Prodigy’s definition more accurately describes the claimed invention. Prodigy wants the definition of “first portion” to limit the form of the display at the remote terminal to “a plurality of parallel lines of alphanumeric and/or graphical data constituting a screen.” It contends that the phrase “first portion containing information for display” used in the claim has no plain English meaning, and thus must be defined by recourse to the preferred embodiment set forth in the specification. This is nonsense. The phrase “first portion containing information for display” can be readily understood by the lay reader (of which this Court is one). It is not a technical term; the simple English words contained in the phrase need no particular defining, and it can be understood without recourse to any other material. BT is correct when it asserts that, in this instance, Prodigy is attempting to limit the claims to the preferred embodiment, which is improper. Burke, Inc. v. Bruno Indep. Living Aids, Inc., 183 F.3d 1334, 1341 (Fed.Cir.1999). When it comes to defining the “second portion,” however, Prodigy is on the mark: the essential feature of the “second portion” of the block of information is that it contains the - complete address where each of the pages that are referenced in the data displayed on the remote terminal can be found. That is clear from the claim language itself: it states, without any ambiguity whatever, that the block of data includes “a second portion containing information not for display but including the complete address for each of plural other blocks of information.” ’662 patent, col. 6, 11. 21-24. I do, however, note something else. The clear claim language states that the second portion of information includes the complete address for other blocks of information. But the claim language does not state that this is all the second portion includes. Therefore, the second portion might contain other information, as well. The specification confirms that the second portion can include other information in addition to those complete addresses. In fact, it clearly states, “it will be appreciated that the second part of each block could have other uses, both for influencing the nature of the display produced and to reduce the complexity of keying required to communicate with the computer 1 .... ” Id., col. 4,11. 25-37. Therefore, I find that the second portion is not limited to complete addresses alone, but may contain other information, as well. 3. Complete Address The term “complete address” is not difficult to understand. An “address” is “the number or name that uniquely identifies a register, memory location, or storage device in a computer.” Dictionary of Scientific and Technical Terms 27 (Sybil P. Parker ed., McGraw Hill 3d ed.1984) (computer science usage). “Complete” means whole or entire or full. Thus, a block of data’s “complete address” is the entire number or name that uniquely identifies a register, memory location, or storage device in a computer where a block of information will be found. . Prodigy, as usual, wants me to add a number of limitations to this rather straightforward definition. Prodigy argues that the complete address is “a known, unique and unambiguous reference for each block of information, specifying without reference to other information the physical location on the central computer’s mass memory device of the next block of information to be retrieved.” It also asks that I construe the patent as limited to circumstances in which the “next block of information” can always be retrieved in “one memory device cycle.” My first problem with Prodigy’s “known, unique and unambiguous reference” language is that it is unnecessarily wordy. The definition of “address” incorporates the word “unique,” and much of the rest of their proposal is surplusage. The larger issue is whether the complete address is a physical address or whether it may be a virtual one. A virtual address is “a symbol that can be used as a valid address part but does not necessarily designate an actual location.” Dictionary of Scientific and Technical Terms 1732 (Sybil P. Parker ed., McGraw Hill 3d ed.1984) (computer science definition). Virtual addressing encompasses the concept of “pointers.” A pointer is “the part of an instruction which contains the address of the next record to be accessed.” Dictionary of Scientific and Technical Terms 1237 (Sybil P. Parker ed., McGraw Hill 3d ed.1984) (computer science definition). BT argues that the complete address covers virtual addressing because physical and virtual addressing were both known in the art at the time, and nothing in the Sargent patent or its prosecution precludes having a complete address point to another complete address, which ultimately points to the desired block of information. I disagree. Let me review here what the Sargent patent does. This invention stores linking data associated with a given display page together in one block in the main memory with that same display page. (Fedida, for example, differed from this invention by storing the linking information in its own separate location on the main memory disk. The problem with that system was that in order to identify the complete address of the next display page, the main disk store would have to be accessed again.) The point of the Sargent invention is that the linking data is moved to the further memory at the same time as the display page is moved to the remote terminal. This linking data “may subsequently be accessed upon the keying of an abbreviated code (e.g. a single digit) without the need to search through a more comprehensive collection of linking data that might be separately stored somewhere in the main memory disk files.” (Apr. 3, 1984 Amend, at 5-7.) In the Sargent invention, there is no need to go anywhere else other than the further memory in order to call up the next page of information to be displayed. This allows the Sargent invention to call up information quickly by avoiding “bottlenecks” at the main disk store. The Sargent invention “speed[s] up operations by avoiding the necessity for doing a possible further disk access when a user response is received.” (Id. at 7.) During the course of the patent prosecution, the applicant distinguished the NTZ article by stating that his simple addressing system allows the “abbreviated keyed-in data to directly read out the complete address of the next block to be fetched from the main store.” (Dec. 4, 1985 Amend., File Wrapper Tab 16 at 9-10.) In distinguishing the Sargent patent from Tsuda the applicant stated: Indeed, the execution of a “Judge Order” (col. 6, line 40 et seq.) [as described in Tsuda] involves a fairly complex algorithm to determine what next should be displayed. By contrast, the applicant’s novel arrangement permits one to merely directly read out from a ‘further’ memory the next complete address — as addressed by abbreviated input keyed-data. (Id. at 7.) I find the term “directly” in these phrases to mean just that — in a direct manner, rather than an indirect one which would point to an infinite number of other complete addresses before calling up the next block of information. A virtual address is simply not a complete address. In its decision to allow the claims, the Patent Board of Appeals stated that: We find no indication, however, that the ‘Request Order’ [taught by Tsuda] includes the complete address of the next block of information which is to be retrieved and utilized for display purposes as claimed. At most it would appear to us from a review of the [prior art] that the data included in the request order [taught by Tsuda] would be used by the computer [] for determining such an address. (Prodigy Br., Ex. 12, p. 4.) This passage lends the strongest support to Prodigy’s argument that the “complete address” does not reference another address, but rather, that the “complete address” is what is referenced. A complete address is therefore more than simply the address by which the central computer is able to retrieve a block of information. The complete address calls up the block of information directly, without reference to another address. The operating system software of the computer that Sargent referenced as implementing the Viewdata system may have included the capability of using pointers. (See Further Declaration of Graham David Turner, Ex. B, at § 3.2.) However, the applicant’s arguments to the Patent Board regarding his invention indicated that the complete address directly called up the blocks of information without referencing other information. I decline to include Prodigy’s additional language that the complete address enables retrieval of a block of information in one memory access cycle. Prodigy notes that, in a 1984 Amendment, applicant emphasized to the patent office that the Sargent invention constituted an improvement over the Fedida prior art reference because “the present application has described and claimed a novel system structure wherein linking data is stored together in the main memory with that same display page as a block of commonly accessed data such that it is jointly accessed in one access cycle.” (Apr. 3, 1984 Amend, at 6 (emphasis in original).) However, this passage only refers to the fact that the first and second portions (linking data and display page) can be accessed in a single memory cycle (which is a necessary accoutrement of their being stored as a block). Prodigy cites several similar references in support of their argument. (August 28, 1983 Amend, at 8-9; January 24, 1986 Appeal Br. at 3.) I find that these citations refer to the fact that the Sargent patent eliminates the need for multiple accesses to the main disk store, rather than to any suggestion that the block of information must be retrieved in one memory access cycle. The complete address must also be “predetermined.” Again, the parties complicate matters without need when they try to read too much into the “predetermined” nature of the address. An address is “predetermined” if it is determined prior to the block of data’s being selected by the operator at the remote terminal. Contrary to Prodigy’s assertion, it is not necessary to decide precisely when the predetermined address must be determined in order to construe the claim language — though as Prodigy points out, it may be necessary for anyone using the invention to predetermine addresses at some particular point in order for a product using the invention to work properly. 4. Respectively Corresponding Locations The next term that I must address is “respectively corresponding locations.” According to the technical dictionary, a location is “any place in which data may be stored.” Dictionary of Scientific and Technical Terms 932 (Sybil P. Parker ed., McGraw Hill 3d ed.1984) (computer science definition). Respectively corresponding locations are places on the central computer’s main store where blocks of information are stored. According to the claim language, each of these locations has a predetermined address that corresponds to the location. The main point of contention between the parties regarding this claim phrase is how the blocks of information are stored. BT argues that the locations need not be physical locations because the c