Opinion ID: 765349
Heading Depth: 3
Heading Rank: 1

Heading: A game apparatus, comprising:

Text: 18 a reel mounted for rotation about an axis through a predetermined number of radial positions; 19 means to start rotation of said reel about said axis; 20 indicia fixed to said reel to indicate the angular rotational position of said reel; 21 means for assigning a plurality of numbers representing said angular positions of said reel, said plurality of numbers exceeding said predetermined number of radial positions such that some rotational positions are represented by a plurality of numbers; 22 means for randomly selecting one of said plurality of assigned numbers; and means for stopping said reel at the angular position represented by said selected number. 23 Telnaes, col. 5, lines 38-53. 24 It is undisputed that the first three limitations of claim 1 read on the accused device, the WMS 400 slot machine. The parties' dispute involves the last three limitations, which are written in means-plus-function format, pursuant to 35 U.S.C. 112, 6 (1994). Under that provision, [a]n 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. We have stated that for a means-plus-function limitation to read [literally] on an accused device, the accused device must employ means identical to or the equivalent of the structures, material, or acts described in the patent specification. The accused device must also perform the identical function as specified in the claims. Valmont Indus., Inc. v. Reinke Mfg. Co., 983 F.2d 1039, 1042, 25 USPQ2d 1451, 1454 (Fed. Cir. 1993); see also Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 934, 4 USPQ2d 1737, 1739 (Fed. Cir. 1987) (en banc) (To determine whether a claim limitation is met literally, where expressed as a means for performing a stated function, the court must compare the accused structure with the disclosed structure, and must find equivalent structure as well as identity of claimed function for that structure.) (emphasis in original). Determining the claimed function and the corresponding structure for a claim limitation written in means-plus-function format are both matters of claim construction. They therefore present issues of law that we review de novo. See Chiuminatta Concrete Concepts, Inc. v. Cardinal Indus., Inc., 145 F.3d 1303, 1308, 46 USPQ2d 1752, 1755-56 (Fed. Cir. 1998). 25 Construing the Disputed Limitations of Claim 1 26 As far as claim construction is concerned, our task is to identify the claimed function and the corresponding structure of each of the three disputed limitations of claim 1. We begin with the first of the three disputed limitations: means for assigning a plurality of numbers representing said angular positions of said reel, said plurality of numbers exceeding said predetermined number of radial positions such that some rotational positions are represented by a plurality of numbers. This limitation contains the terms angular positions, radial positions, and rotational positions. The district court construed each of these terms to refer to stop positions of the reel. Neither party challenges that construction. 27 The claimed function of the means for assigning limitation is assigning a plurality of numbers representing said angular positions of said reel, said plurality of numbers exceeding said predetermined number of radial positions such that some rotational positions are represented by a plurality of numbers. In other words, the claimed function is assigning a plurality of numbers to stop positions, where the plurality of numbers exceeds the number of stop positions and some stop positions are represented by more than one number. 28 In regard to the disclosed corresponding structure of the means for assigning limitation, WMS and IGT stipulated--and the district court accepted the stipulation--that the Telnaes patent discloses a microprocessor, or computer, to control the operation of the slot machine, including the operation of the machine in the assignment of numbers to reel stop positions. 2 The algorithm that controls the assignment of numbers to stop positions is disclosed in Figure 6 of the Telnaes patent. Figure 6 illustrates an algorithm in which a plurality of single numbers are assigned to stop positions such that: 1) the range of single numbers exceeds the number of stop positions; 2) each single number is assigned to only one stop position; 3) each stop position is assigned at least one single number; and 4) at least one stop position is assigned more than one single number. The prosecution history reinforces the teachings of Figure 6. The prosecution history indicates that each number must correspond to a stop position, but that several numbers may correspond to the same stop position. In response to an Office Action, Telnaes stated, the applicant has disclosed a machine which utilizes a standard mechanism but on which the odds can be changed substantially infinitely. The only guidelines are that there must be a symbol for each symbol indicator in virtual memory but there can be many positions in the virtual memory for each symbol on the reel. 29 The district court construed the means for assigning limitation of claim 1 to cover any table, formula, or algorithm for determining correspondence between the [randomly selected] numbers and rotational positions of the reel. WMS argues that this construction was overly broad. It contends that the means for assigning limitation should have been defined by the corresponding structure, material, or acts described in the patent specification, or their equivalents, and should have been further limited by the prosecution history. IGT responds that the court properly construed the claim. 30 We agree with WMS that the district court's construction of the means for assigning limitation was overly broad. The written description of the Telnaes patent is almost completely devoid of any structure to support this limitation of the claim. The district court apparently took this lack of disclosure to indicate that the limitation reads on any means for performing the recited function. However, this construction is at odds with the requirements of 35 U.S.C. 112. See Valmont Indus., 983 F.2d at 1042, 25 USPQ2d at 1454 (holding that section 112, 6, permits the use of means-plus-function language in claims, but with the proviso that the claims are limited to the structure, material, or acts disclosed in the specification and their equivalents). 31 The district court determined that the structure disclosed in the specification to perform the claimed function was an algorithm executed by a computer. While this finding accurately reflected the parties' stipulation, the court erred by failing to limit the claim to the algorithm disclosed in the specification. The structure of a microprocessor programmed to carry out an algorithm is limited by the disclosed algorithm. A general purpose computer, or microprocessor, programmed to carry out an algorithm creates a new machine, because a general purpose computer in effect becomes a special purpose computer once it is programmed to perform particular functions pursuant to instructions from program software. In re Alappat, 33 F.3d 1526, 1545, 31 USPQ2d 1545, 1558 (Fed. Cir. 1994) (en banc); see In re Bernhart, 417 F.2d 1395, 1399-1400, 163 USPQ 611, 615-16 (CCPA 1969) ([I]f a machine is programmed in a certain new and unobvious way, it is physically different from the machine without that program; its memory elements are differently arranged.). The instructions of the software program that carry out the algorithm electrically change the general purpose computer by creating electrical paths within the device. These electrical paths create a special purpose machine for carrying out the particular algorithm. 3 32 In a means-plus-function claim in which the disclosed structure is a computer, or microprocessor, programmed to carry out an algorithm, the disclosed structure is not the general purpose computer, but rather the special purpose computer programmed to perform the disclosed algorithm. See Alappat, 33 F.3d at 1545, 31 USPQ2d at 1558. 4 Accordingly, the structure disclosed for the means for assigning limitation of claim 1 of the Telnaes patent is a microprocessor programmed to perform the algorithm illustrated in Figure 6. In other words, the disclosed structure is a microprocessor programmed to assign a plurality of single numbers to stop positions such that: 1) the number of single numbers exceeds the number of stop positions; 2) each single number is assigned to only one stop position; 3) each stop position is assigned at least one single number; and 4) at least one stop position is assigned more than one single number. 33 We turn next to the second disputed limitation of claim 1: means for randomly selecting one of said plurality of assigned numbers. As the language of the claim makes clear, the function of this limitation is randomly selecting one of said plurality of assigned numbers. In other words, the claimed function is randomly selecting one of the numbers that was assigned to reel stop positions by the means for assigning limitation just discussed. The district court concluded, and the parties agree, that the corresponding structure disclosed in the specification is a microprocessor programmed to perform random number generation. The random number generator randomly selects a single number from the range of numbers assigned by the means for assigning limitation. Telnaes, col. 3, lines 1-9. For the reasons indicated in footnote 2 above, we will not disturb the district court's claim construction. 34 Finally, we consider the third disputed limitation of claim 1: means for stopping said reel at the angular position represented by said selected number. 5 The claimed function is stopping the reel at the stop position that corresponds to the random number selected by the means for randomly selecting limitation. The disclosed structure is a brake. Neither of these points is in dispute. 35 As just seen, the functions of the three disputed limitations of claim 1 are: 1) assigning a plurality of numbers to stop positions, where the plurality of numbers exceeds the number of stop positions and at least one stop position is represented by more than one number; 2) randomly selecting one of the numbers assigned to stop positions; and 3) stopping the reel at the stop position that corresponds to the selected number. Referring to the means for selecting and means for stopping limitations, WMS argues that selecting one number and stopping the reel at the stop position represented by said selected number indicates that claim 1 is limited to assigning and selecting single numbers rather than combinations of numbers. The district court concluded, however, that: [t]here is nothing in the claim that limits the generated numbers to be a single number. WMS Gaming, slip op. at 26. We agree with WMS on this point. The plain meaning of selecting one of said . . . numbers is selecting a single number, not a combination of numbers. See Insituform Techs., Inc. v. Cat Contracting, Inc., 99 F.3d 1098, 1105, 40 USPQ2d 1602, 1607 (Fed. Cir. 1996) (determining that the claim term a cup suggests the use of only one cup). In addition, the last limitation of the claim refers to said selected number. This reference to number in the singular sense bolsters the interpretation that selecting one of said . . . numbers is limited to selecting a single number. Nothing in the written description, drawings, or prosecution history indicates that the phrases one of said . . . numbers or said selected number should be given anything other than their ordinary meaning. See York Prods., Inc. v. Central Tractor Farm & Family Ctr., 99 F.3d 1568, 1572, 40 USPQ2d 1619, 1622 (Fed. Cir. 1996) (Without an express intent to impart a novel meaning to claim terms, an inventor's claim terms take on their ordinary meaning.). Therefore, the term number(s), as used in claim 1, refers to single numbers, as opposed to combinations of numbers, and the recited function of claim 1 is limited to assigning and selecting single numbers. Literal Infringement of Claim 1 36 Having considered claim construction, we turn to the issue of infringement of claim 1. We address literal infringement first. To prove literal infringement, the patentee must show that the accused device contains every limitation in the asserted claims. If even one limitation is missing or not met as claimed, there is no literal infringement. Mas-Hamilton Group v. LaGard, Inc., 156 F.3d 1206, 1211, 48 USPQ2d 1010, 1014-15 (Fed. Cir. 1998) (citations omitted). As noted above, in order to establish literal infringement of a means-plus-function claim, the patentee must establish that the accused device employs structure identical or equivalent to the structure disclosed in the patent and that the accused device performs the identical function specified in the claim. See Valmont Indus., 983 F.2d at 1042, 25 USPQ2d at 1454; Pennwalt, 833 F.2d at 934, 4 USPQ2d at 1739. It is undisputed that the first three limitations of claim 1 are met in the accused device, the WMS 400 slot machine. The issue, then, is whether IGT carried its burden of establishing that, as properly construed, the last three limitations of claim 1 read on the WMS 400 slot machine. 37 As a preliminary matter, the WMS 400 slot machine does not contain structure identical to that disclosed in the Telnaes patent for the last three limitations of claim 1. The two structures are not identical because the microprocessor disclosed in the Telnaes patent is programmed differently from the microprocessor disclosed in the Durham patent. Put another way, the two disclosed machines are different, i.e., not identical. As discussed above, in the Telnaes patent the structure disclosed for the means for assigning limitation of claim 1 is a microprocessor programmed to assign a plurality of single numbers to stop positions such that: (1) the range of single numbers exceeds the number of stop positions; (2) each single number is assigned to only one stop position; (3) each stop position is assigned at least one single number; and (4) at least one stop position is assigned more than one single number. The WMS 400 slot machine is not programmed in an identical manner. This is made clear by the descriptions, in Part I of the BACKGROUND section of this opinion, of the slot machine disclosed in the Telnaes patent and the WMS 400 slot machine. Because the structures of the two machines are not identical, the issue of literal infringement of claim 1, as far as structural limitations are concerned, turns on whether the WMS 400 slot machine has structure equivalent to the means for assigning a plurality of numbers and the means for randomly selecting one of said plurality of assigned numbers limitations of the claim. 38 The proper test for determining whether the structure in an accused device is equivalent to the structure recited in a section 112, 6, claim is whether the differences between the structure in the accused device and any disclosed in the specification are insubstantial. See Chiuminatta, 145 F.3d at 1309, 46 USPQ2d at 1756; Alpex Computer Corp. v. Nintendo Co., 102 F.3d 1214, 1222, 40 USPQ2d 1667, 1673 (Fed. Cir. 1996). Because the structure recited in the Telnaes patent is limited by the disclosed algorithm, our analysis of structural equivalence necessarily discusses the disclosed algorithm, which includes functional-type elements. 39 As discussed above, the WMS 400 slot machine selects two random numbers (R1 and R2) and maps those numbers to two payoff multipliers (X and Y). The payoff amount (Z) is calculated by multiplying X times Y. A third random number (R3) selects a stop position for each reel based on the groups of reel stop positions that correspond to the payoff amount. In other words, the accused device assigns a combination of numbers to each stop position. 40 Thus, in this case the issue of equivalent structure turns on whether a machine that assigns combinations of numbers to reel stop positions, which is what the WMS 400 slot machine does, is equivalent to the structure disclosed in the Telnaes patent, which teaches a machine that assigns single numbers to reel stop positions. 41 Addressing the means for assigning limitation of claim 1, the district court found that: 42 one skilled in the art would consider it an insubstantial change to substitute combinations of numbers [for single numbers] . . . where necessary to conform to the algorithm selected or memory constraints. Therefore, at the very least, combinations of numbers or other sets of randomly selected elements would be equivalent to the plurality of numbers selected by the microprocessor. 43 WMS Gaming, slip op. at 26. As far as the means for randomly selecting limitation was concerned, the court found that using the random number generator algorithm several times to select a combination of numbers, as in the WMS 400 slot machine, was equivalent to selecting a single number, as in the Telnaes patent. Based upon its findings, the district court determined that the structure of the WMS 400 slot machine was equivalent to the structure disclosed for the two penultimate limitations of claim 1 of the Telnaes patent. In reaching this conclusion, the court apparently relied on the testimony of IGT's expert, Jonathan Fry, who testified that randomly assigning and selecting combinations of single numbers is a minor difference from assigning and selecting single numbers. 44 On appeal, WMS argues that there are no equivalents to the disclosed structure and that the district court applied the wrong standard by focusing on equivalent results rather than equivalent structure. Discerning no clear error in the district court's finding of equivalent structure, we reject these arguments. 45 In the claimed invention, each stop position on a reel is assigned one or more single numbers. In the accused device, each stop position on a reel is assigned one or more combinations of single numbers. For example, the first reel in the WMS 400 slot machine displays the first double-bar symbol if the payoff amount is 100 and the third iteration of the random number generator selects a number between one and four (memory positions A-D). Durham, Figure 8. Accordingly, the first reel displays the first double-bar symbol if R1 is 1, R2 is between 2 and 23, and R3 is between 1 and 4. Id., Figures 5, 6, and 8. The first double-bar symbol of the first reel therefore is effectively assigned the 88 combinations of numbers comprising the set [R1, R2, R3] of [1, 2-23, 1-4]. 46 In the WMS 400 slot machine, most combinations of numbers assigned to reel stop positions include three numbers, but some include only two numbers. As discussed above, the combination of numbers assigned to the first double-bar symbol includes R1, R2 and R3. If there is only one way to display a payoff amount, however, then the selection of R3 is not required and the combination of numbers assigned to the stop position that represents that payoff amount may only include two numbers. For example, there is only one 7 on each reel, and the group of symbols 7 7 7 is the only way to display a payoff amount of 1000. A payoff amount of 1000 corresponds only to R1 equal to one (X = 10) and R2 equal to one (Y = 100). Durham, Figures 5 and 6. Thus, the symbol 7 on each reel is assigned the combination of numbers [1,1]. Finally, the accused device includes a random number generator that randomly selects combinations of two or three numbers, as required by the means for selecting limitation, and a brake, as required by the means for stopping limitation. 47 In the case of both the machine disclosed in the Telnaes patent and the WMS 400 slot machine, each reel stop position is assigned a tag that uniquely identifies the stop position. In the case of the Telnaes patent, each tag is denoted by a single number selected from a plurality of numbers. In the case of the accused device, each tag is denoted by a combination of single numbers selected from a plurality of combinations of single numbers. Whether selecting a tag denoted by a single number is the structural equivalent of selecting a tag denoted by a combination of single numbers is a close question. In view of the fact that there is enough credible evidence in the record, in the form of the Durham patents and the testimony from IGT's expert, Jonathan Fry, that the difference between assigning and selecting single numbers and assigning and selecting combinations of single numbers is insubstantial, we are not prepared to hold that the district court clearly erred in finding equivalent structure. 48 Turning now to the issue of identity of function, the functional limitations of the three disputed limitations of claim 1 do not literally read on the accused device. The two penultimate limitations of claim 1 are the means for assigning and the means for selecting limitations. We have held, as a matter of claim construction, that the function of these limitations, taken together, is assigning and selecting single numbers. Because the WMS 400 slot machine assigns and selects combinations of numbers rather than single numbers, it does not perform a function identical to that of claim 1 of the Telnaes patent. Accordingly, although it has equivalent structure, the WMS 400 slot machine does not literally infringe the claim. 6 The district court's holding to that effect is therefore reversed. Infringement of Claim 1 Under the Doctrine of Equivalents 49 A claim that does not literally read on an accused device may nevertheless be infringed under the doctrine of equivalents if the differences between the claim and the accused device are insubstantial. See Hilton Davis Chem. Co. v. Warner-Jenkinson Co., 62 F.3d 1512, 1521-22, 35 USPQ2d 1641, 1648 (Fed. Cir. 1995) (en banc), rev'd on other grounds, Warner-Jenkinson Co. v. Hilton Davis Chem. Co., 520 U.S. 17, 41 USPQ2d 1865 (1997). As noted above, the district court found that the WMS 400 slot machine infringed claim 1 of the Telnaes patent under the doctrine of equivalents. 7 The court stated: WMS Gaming's device's use of multiple random numbers instead of one, in a multi-step process, instead of the more direct, straightforward selection of stopping positions claimed in the [Telnaes] patent, is an insubstantial difference to a person skilled in the art. WMS Gaming, slip op. at 20. 50 Recently, in Chiuminatta Concrete Concepts, Inc. v. Cardinal Industries, Inc., we stated: 51 Both 112, 6, and the doctrine of equivalents protect the substance of a patentee's right to exclude by preventing mere colorable differences or slight improvements from escaping infringement, the former, by incorporating equivalents of disclosed structures into the literal scope of a functional claim limitation, and the latter, by holding as infringements equivalents that are beyond the literal scope of the claim. They do so by applying similar analyses of insubstantiality of the differences. 52 145 F.3d at 1310, 46 USPQ2d at 1758. We went on to point out in Chiuminatta that a lack of equivalent structure under a means-plus-function limitation may preclude a finding of equivalence under the doctrine of equivalents. Id. We stated that such would be the case unless a variant that was accused of infringement--but that did not literally infringe a means-plus-function limitation--was due to technological advances developed after the patent was granted and constitute[d] so insubstantial a change from what [was] claimed in the patent that it should be held to be an infringement. Id. 53 As just seen, our holding that the WMS 400 slot machine does not literally infringe claim 1 of the Telnaes patent is not based on a finding that the accused device lacks structure equivalent to that disclosed in the patent. On the contrary, we have sustained the district court's finding that the WMS 400 slot machine has equivalent structure. However, we have reversed the district court's holding of literal infringement based on a lack of identity of function. Consequently, unlike Chiuminatta, the accused device in this case may still infringe under the doctrine of equivalents. See Al-Site Corp. v. VSI Int'l, Inc., 174 F.3d 1308, 1320-21, 50 USPQ2d 1161, 1167-68 (Fed. Cir. 1999) (an accused device can infringe under the doctrine of equivalents without infringing literally under 35 U.S.C. 112, 6 because the doctrine only requires substantially the same function, not identicality of function as in section 112, 6). 54 The question before us, then, is whether the district court clearly erred in finding that the differences between the WMS 400 slot machine and the claimed invention are insubstantial. In challenging the district court's finding, WMS argues that the district court failed to analyze equivalency on a limitation-by-limitation basis. It also contends that the accused device functions in a different way from the claimed invention, in that it does not assign numbers to stop positions to determine a result, but rather, determines a result before stop positions are selected. 55 We reject WMS's arguments. We discern no clear error in the district court's finding of insubstantial differences between the claimed invention and the accused device. As far as the first argument is concerned, examination of the district court's opinion makes it clear that, in the course of addressing the issue of literal infringement of claim 1 (which involved a determination of the substantiality of the differences between the structure of the claimed invention and the accused device and in which equivalent structure was found), the court properly conducted an element-by-element analysis. See WMS Gaming, slip op. at 10-12, 17-19. 56 WMS's second argument, that the accused device does not assign numbers to stop positions, also fails. While the WMS 400 slot machine performs the step of calculating the payoff amount before selecting the stop positions, this unclaimed extra step does not change the basic character of the device. In the WMS 400 slot machine, each stop position corresponds to at least one combination of numbers and is selected by iteratively choosing a plurality of numbers using a random number generator. Choosing two random numbers, performing mathematical operations to determine the payoff amount, and then choosing a third random number does not change the fact that each stop position is identified by a combination of numbers. The accused device therefore assigns numbers to stop positions as required by claim 1 of the Telnaes patent. 57 In sum, we reverse the district court's holding of literal infringement of claim 1, but affirm its holding of infringement of that claim under the doctrine of equivalents. We therefore reverse the court's holding of literal infringement of claims 2, 4, 5, 6, and 8, but affirm its holding of infringement of those claims under the doctrine of equivalents. We affirm the court's holding of infringement of claims 9 and 10 under the doctrine of equivalents.