The opinion of the court was delivered by: Jed S. Rakoff, U.S.D.J.
In this patent infringement action, plaintiff Fifth Generation Computer Corporation ("Fifth Generation"), the current owner of U.S. Patents 4,860,201 ("the '201 Patent") and 6,000,024 ("the '024 Patent") alleges that defendant International Business Machines Corporation ("IBM") infringed one or both of those patents. Following briefing, the Court held a "Markman" hearing on August 20, 2009 to hear testimony as to the meaning of the disputed terms of the patents here in issue. See Markman v. Westview Instruments, Inc., 517 U.S. 370 (1996). On August 31, 2009, the Court issued a "bottom-line" Order that construed the disputed terms. This Opinion and Order provides the reasons for those constructions.
Familiarity with the parties' submissions and the testimony presented at the Markman hearing is here assumed. Generally speaking, the patents at issue relate to the means by which computers process data and are designed to increase the speed with which certain computational tasks are completed. In these patents, increases in speed are accomplished through parallel processing, whereby tasks are divided into smaller tasks that are performed simultaneously. Markman Tutorial at 2.*fn1 The parallel processing is achieved through the use of one type of parallel computer: the "binary tree" computer. Id. In a binary tree computer, each processor (or node) is connected to one or more "child" or "leaf" processors (or nodes) to form communication "trees." Id. at 3.
In particular, the '201 patent (issued on August 22, 1989 to Salvatore J. Stolfo and Daniel P. Miranker) seeks to improve upon previous systems that suffered "propagation delays" (i.e., delays from computing and communicating the data up and down a tree) that resulted from the processors' handling both computing and communicating functions. '201 Patent at 3:29-32. The '201 patent arranges for a separate input/output device to accompany each processing element to handle the broadcast and reporting of information up and down the "binary tree" (a disputed term), thus dedicating the processing elements to other tasks. Id. at 4:64-5:2.
The '024 patent (issued on December 7, 1999 to James L. Maddox) describes a binary tree computer system that attempts to improve on the '201 patent. Here, a series of "bus controllers" (a disputed term) control information flow in the system and are arranged in a binary tree configuration. '024 Patent at 1:48-49. Processors are attached to these bus controllers to form a binary tree of processing elements. Id. at 54-55. In contrast with the '201 patent, in which each processor has its own I/O device, in the '024 patent the bus controllers are themselves arranged in a binary tree configuration. At the extremes, the bus controllers are connected to a set of leaf processing elements -- that is, the bus controllers at the extremes have more than one processing element connected to them. The bus controllers "act collectively as a bucket brigade," '024 Patent at 5:38-39, to transfer information throughout the computer system.
With this background in mind, the Court turns first to the disputed terms of the '201 patent.
The first term in dispute is "binary tree," which appears in every claim in the '201 Patent, including the four here relevant: Claims 1, 4, 7, and 8. (Claim 1 is an independent claim, and 4, 7, and 8 are dependent.) Claim 1 reads in relevant part: "A parallel processor array comprising . . . means for interconnecting said processing elements in a binary tree in which each processing element except those at the extremities of the binary tree is connected to one parent processing element and at least first and second child processing elements." '201 Patent at 69:60, 67-69; 70:59-60.
Plaintiff's proposed construction is "a tree where a node has a parent node (except for the root node) and zero, one or two children." Fifth Generation's Rebuttal Markman Brief ("Pl. Reply") at 3. In contrast, defendant reads the term as "an arrangement of nodes where each node has a single parent and two children nodes, except the root node, which has no parent, and the leaf nodes, which have no children." IBM's Opening Markman Brief ("Def. Br.") at 9.
In Phillips v. AWH Corp., 415 F.3d 1303 (Fed Cir. 2005) (en banc), the Federal Circuit explained that "the words of a claim are generally given their ordinary and customary meaning" and that "the ordinary and customary meaning of a claim term is the meaning that the term would have to a person of ordinary skill in the art in question at the time of the invention, i.e., as of the effective filing date of the patent application." Id. at 1312-13. Here, plaintiff asserts that its construction reflects the "ordinary meaning" of the term "binary tree," Pl. Reply at 3; see also tr. 08/20/09 at 48, and cites both to the dictionary of the National Institute of Standards and Technology ("NIST"), in which "binary tree" is defined as "a tree with at most two children for each node," and to IBM's own website, on which appears a similar definition. See E-Pass Technologies, Inc. v. 3Com Corp., 343 F.3d 1364, 1367 (Fed. Cir. 2003) ("We resort initially to the relevant dictionary definitions to determine the ordinary meaning of the [disputed] term . . . .").
However, since the '201 patent was filed in 1986, see '201 Patent at 1, the relevant meaning is the meaning at the time of the invention, see Phillips, 415 F.3d at 1313; PC Connector Solutions LLC v. SmartDisk Corp., 406 F.3d 1359, 1363 (Fed. Cir. 2005) ("A claim cannot have different meanings at different times; its meaning must be interpreted as of its effective filing date."), and there is no evidence before the Court that establishes what the dictionary definition of "binary tree" was in 1986. Indeed, it appears on this record that there was no entry for "binary tree" in either the 1986 version of the NIST dictionary nor in the contemporaneous version of IBM's Dictionary of Computing published in March 1987. See Def. Letter, 09/27/09. Given the huge changes in computer data processing, and accompanying jargon, between 1986 and the present, resort to NIST and IBM dictionaries from the present does not resolve the issue of the term's ordinary meaning.
The Court must therefore look to the usage of the claim term in the context of the particular claim and in the context of the entire patent as submitted in 1986. See Phillips, 415 F.3d at 1313 ("[T]he person of ordinary skill in the art is deemed to read the claim term not only in the context of the particular claim in which the disputed term appears but in the context of the entire patent, including the specification.").
The parties agree that the structure of Claim 1, the means-plus function language of "means for interconnecting," requires that the binary tree contemplated by Claim 1 have two children for each processing element except for those at the extremities. See tr., 08/20/09, at 44. Yet, plaintiff's proposed construction contradicts the language of Claim 1 and flies in the face of this structure. Taking plaintiff's construction on its face, a node with a single parent could have a single child, and that child could, in turn, have another single child, thus creating a straight line from one node to another, and this structure would still be a "binary tree" even though there is nothing binary about it. See tr., 08/20/09, at 46. Indeed, plaintiff's construction would eliminate what plaintiff itself takes to be the preferred embodiment and therefore cannot be the proper construction. See Primos Inc. v. Hunter's Specialties, Inc., 451 F.3d 841, 848 (Fed. Cir. 2006) ("While we are mindful that we cannot import limitations from the preferred embodiments into the claim, we also should not normally interpret a claim term to exclude a preferred embodiment.").
Moreover, plaintiff can point to only one sentence in the patent specification that remotely provides support for its construction: "Since the subtree that is computing the resolve need not be a complete binary tree, the value bits from the children may not arrive in the same clock cycle." '201 Patent at 21:46-49. Plaintiff asserts that this phrase from the patent specification indicates that the term "binary tree" permits a tree with zero, one or two children. Pl. Reply at 4. Yet this phrase does not define the binary tree qua structure --- it only indicates that some tasks may rely on longer legs of a subtree, and thus the report and resolve functions would not be completed simultaneously. See tr., 08/20/09, at 55.
IBM's construction does not suffer from these difficulties; but plaintiff contends that IBM's construction improperly imports limitations from the preferred embodiment, see Phillips, 415 F.3d at 1323, because the preferred embodiment in no way offers a "clear disavowal" of embodiments of the binary tree computing system having less than two child nodes. Pl. Reply at 4. By way of support, plaintiff underscores the fact that the patent identifies Figure 2 as "the general configuration of a preferred embodiment of the invention comprising a binary tree of 1023 processing elements." '201 Patent at 8:11-13. In actuality, however, defendant's proposed construction does not import a limitation from the specification, but, rather, it relies on the fact that "the specification is the single best guide to the meaning of a disputed term," Phillips, 415 F.3d at 1320 (internal quotation marks omitted). Here, in fact, the specification is more properly read as dictating the correct scope of the claim, and in this respect, the "the inventor's intention, as expressed in the specification, is regarded as dispositive." Id. at 1316. In this regard, defendant has pointed not only to the claim language itself but numerous instances throughout the specification that confirm that the binary tree contemplated by the patent requires each processing element, except for the root node and the extremities, to have two children. The patent abstract describes the patent as "a plurality of parallel processing elements [. . .] connected in a binary tree configuration, with each processing element except those at the highest and lowest levels being in communication with a single parent processing element as well as the first and second (or left and right) child processing elements." '201 Patent Abstract. The same information is repeated in the section of the patent devoted to the background of the invention, as well as the summary of the invention. Id. at 1:62-65; 4:56-62; see also Modine Mfg. Co. v. U.S. Int'l Trade Comm'n, 75 F.3d 1545, 1551 (Fed. Cir. 1996) ("[W]hen the preferred embodiment is described in the specification as the invention itself, the claims are not necessarily entitled to a scope broader than that embodiment.").
Nor is the holding of E-Pass, upon which plaintiff relies heavily, see tr. 08/20/09 at 25, 29, to the contrary. There, the Federal Circuit overturned the district court's construction of "electronic multi-function card" as "[a] device having the width and outer dimensions of a standard credit card with an embedded electronic circuit." E-Pass, 343 F.3d at 1366. The Federal Circuit found that the district court had taken the preferred embodiment to impose a particular size on the term "card," ignoring language elsewhere in the patent that suggested that the patent was not based on the standardized size of a credit card. Id. at 1370. Here, in contrast, the binary tree that appears in Figure 2 may be a preferred embodiment, but Figure 2 does not suggest that the requirement of two children except at the extremities is a limitation derived from that preferred embodiment. Indeed, the patent elsewhere states directly: "In a binary tree computer, a large number of processors are connected so that each processor except those at the root and leaves of the tree has a single parent processor and two children processors." '201 Patent at 1:62-65. This statement provides critical support for the idea that the definition given to the term "binary tree" by the patentee differs from plaintiff's proposed construction and conforms more closely with defendant's proposed construction. See Phillips, 415 F.3d at 1316 (emphasizing the role of the inventor as "lexicographer").
Based on the foregoing, the Court construes "binary tree" to mean an arrangement of nodes where each node has a single parent and two children nodes, except the root node, which has no parent, and the leaf nodes, which have no children.
The term "subtree" likewise appears in every claim. Claim 1 explains that the input/output provides a "means for broadcasting received from a parent processing element to said child processing elements, such that common information is distributed to each processing element of the binary tree or a subtree thereof . . . ." '201 Patent at 70:62-66.
Plaintiff construes "subtree" to mean "a partitionable portion of a tree that is less than the entire tree created by arbitrarily denoting a node to be the root node in a tree," Fifth Generation's Opening Markman Brief on Claim Construction ("Pl. Br.") at 13, asserting that this construction is consistent with ordinary meaning "in the art of computing."*fn2 Id. Defendant construes the term as "a subset of the binary tree such that each node has a single parent and two children nodes, except the root node, which has no parent, and the leaf nodes, which have no children." Def. Br. at 10.
The parties essentially agree that a subtree is a subdivision of the main binary tree and that a subtree is itself a binary tree with the full functionality of the main binary tree of which it is a subpart. Pl. Br. at 13; Def. Br. at 10-11; Pl. Reply at 7. U.S. Patent No. 4,843,540 ("the '540 Patent") is incorporated by reference into the '201 Patent, and the '540 Patent establishes that "one of the characteristics of the binary tree" is that "it includes sub-sets which are also binary trees." '540 Patent at 3:49-51.
To support its construction, plaintiff cites as extrinsic evidence IBM's Terminology webpage, which defines "subtree" as "a tree structure created by arbitrarily denoting a node to be the root node in a tree." Pl. Br. at 13; Pl. Reply at 6. The '201 patent, according to plaintiff, is consistent with this definition, which describes a binary tree as capable of being "partitioned into any number of subtrees, which maintain the functionality of the tree." Pl. Br. at 13. Yet this extrinsic evidence is insufficient to support this construction, especially in light of the intrinsic evidence, as well as this Court's determination of the proper construction of "binary tree." See Vitronics Corp. v. Conceptronic, 90 F.3d 1576, 1583 (Fed. Cir. 1996) ("In most situations, an analysis of the intrinsic evidence alone will resolve any ambiguity in a disputed claim term. In such circumstances, it is improper to rely on extrinsic evidence."). Not only does the definition upon which plaintiff relies not reflect the meaning of the patent at the time of filing in 1986, see Phillips, 415 F.3d at 1313, but it impermissibly permits any node, including a node with zero children, such as one of the extremities, to be designated a root node, despite the fact that plaintiff concedes that the subtree must also be a binary tree. See Nystrom v. Trex, Co., 424 F.3d 1136, 1145 (Fed. Cir. 2005) ("In the absence of something in the written description and/or prosecution history to provide explicit or implicit notice to the public -- i.e., those of ordinary skill in the art -- that the inventor intended a disputed term to cover more than the ordinary and customary meaning revealed by the context of the intrinsic record, it is improper to read the term to encompass a broader definition simply because it may be found in a dictionary, treatise, or other extrinsic source."). Moreover, since the Court has rejected plaintiff's construction of binary tree, which would have permitted a parent node with zero children, so too must it reject plaintiff's similar construction of "subtree."
Plaintiff objects to defendant's construction on the ground that it requires that the "root node" have no parent node. Pl. Reply at 7. The '201 and '540 Patents both establish clearly that subtrees, as partitions, remain connected to higher level nodes in a larger tree. See '540 Patent at 15:61-64. Yet plaintiff concedes that defendant's construction is accurate if it is understood that a subtree's lack of a parent node does not mean that the subtree is not connected to a higher level node, but rather that the higher level node is itself not considered part of the subtree. Pl. Reply at 8 n. 2; see also tr., 08/20/09, at 55. The Court agrees that this is the proper understanding of that construction.
Nor does defendant improperly rely on the functionality of the subtree to dictate its structure, as plaintiff suggests. See Pl. Reply at 7. As it did in the context of a binary tree, plaintiff cites to a single statement in the '201 Patent for the idea that a subtree need not have the same structure: "Since the subtree that is computing the resolve need not be a complete binary tree, the value bits from the children may not arrive in the same clock cycle." '201 Patent at 21:46-49. Yet, as noted previously, this establishes only that the report and resolve functions would not happen simultaneously if a longer leg of the subtree were handling a particular task. See tr., 08/20/09, at 55. It does not, contrary to plaintiff's position, permit a subtree to have a different structure than a binary tree, namely, a parent with one or zero children. Indeed, plaintiff concedes that the subtree must have the same structure as the larger tree. See Pl. Reply at 8 n.3.
The Court thus confirms its construction that "subtree" means a subset of the binary tree such that each node has a single parent and two children nodes, except the root node, which has no parent, and the leaf nodes, which have no children. The Court's construction should be understood to mean that the parent node nevertheless remains connected to a higher level node in the main ...