       NOTE: This disposition is nonprecedential.

  United States Court of Appeals
      for the Federal Circuit
              __________________________

         FIFTH GENERATION COMPUTER
                CORPORATION,
                Plaintiff-Appellant,
                           v.
     INTERNATIONAL BUSINESS MACHINES
              CORPORATION,
              Defendant-Appellee.
              __________________________

                      2010-1201
              __________________________

   Appeal from the United States District Court for the
Southern District of New York in Case No. 09-CV-2439,
Judge Jed S. Rakoff.
             ____________________________

              Decided: January 26, 2011
             ____________________________

    DAVID B. TULCHIN, Sullivan & Cromwell LLP, of New
York, New York, argued for plaintiff-appellant. With him
on the brief was JAMES T. WILLIAMS.

    JOHN M. DESMARAIS, Desmarais LLP, of New York,
New York, argued for defendant-appellee. With him on
the brief was ALAN K. KELLMAN. Of counsel on the brief
FIFTH GENERATION   v. INTL BUSINESS                      2


were STEVEN C. CHERNY, Kirkland & Ellis LLP, of New
York, New York and JOHN C. O’QUINN, of Washington,
DC.

               __________________________

   Before RADER, Chief Judge, and LOURIE and MOORE,
                    Circuit Judges.
LOURIE, Circuit Judge.
    Fifth Generation Computer Corporation (“Fifth Gen-
eration”) appeals from the dismissal by the District Court
for the Southern District of New York of its suit against
International Business Machines Corporation (“IBM”) for
infringement of U.S. Patent 6,000,024 (the “’024 patent”).
Following the court’s claim construction, Fifth Generation
Computer Corp. v. Int’l Business Machines Corp., 678 F.
Supp. 2d 184 (S.D.N.Y. 2010), the parties stipulated to
noninfringement of the asserted patent claims by IBM’s
accused computer system. The district court entered
judgment of noninfringement in favor of IBM. Because
we construe at least one of the disputed terms in the same
manner as the district court did, we affirm its judgment of
noninfringement.
                       BACKGROUND
    Fifth Generation owns the ’024 patent directed to a
binary tree parallel computing system and issued to
James Maddox, Fifth Generation’s chief engineer. Paral-
lel computing systems seek to increase their speed and
processing power by employing multiple computer proces-
sors that operate simultaneously. The system divides
computing tasks among the several processors, thus
increasing the number of computations that can be per-
formed in a given period of time. The parallel processing
system claimed in the ’024 patent is one configured as a
3                        FIFTH GENERATION   v. INTL BUSINESS


“binary tree” system. ’024 patent, Abstract. Figure 1
from the ’024 patent depicts an embodiment of the pat-
ented system:




    In the patented computer system, a number of Proces-
sor Elements (“PE”), each comprising a processor, associ-
ated random access memory, and an input/output device,
are connected with each other and with a host computer
(13) over a “binary tree-bus” consisting of bus control
nodes such BC1 (15), BC2 (17) and BC3 (19). ’024 patent,
col.2 ll.28-36. As can be seen in Figure 1 of the ’024
patent, each node is connected to its own PE and, depend-
ing upon the location of the node, to either two “child bus
control nodes” or two “leaf PEs.” Id., col.2 ll.43-49 (“The
nodes BC2 and BC3 are each connected to their own PE’s,
PE2 and PE3 respectively, and to left and right child PEs,
PE4 and PE5, and PE6 and PE7, respectively. . . . referred
to as the leaf PE’s since they have no other children.”).
One of the bus control nodes, a “root node” (15), attaches
FIFTH GENERATION   v. INTL BUSINESS                       4


the tree to the host through a driver (14) and a PCI bus
(16). ’024 patent, col.2 ll.50-53. The root node can receive
a problem to be solved from the host computer and dis-
tribute a portion of the problem to each PE in the tree.
The PEs then execute the system’s instructions, i.e.,
perform the necessary calculations, and pass their solu-
tions back up the tree toward the root node, which deter-
mines the overall solution to the problem it received from
the host computer. The input/output device in each PE
functions to transmit data up and down the tree levels.
Claim 1 is representative of the patented parallel comput-
ing system:
       1. A binary tree computer system for connec-
   tion to and control by a host computer, comprising:
       N bus controllers connected in a binary
       tree configuration in which each bus con-
       troller, except those at the extremes of the
       tree, are connected to left and right child
       bus controllers, where N is an integer
       greater than 2, one of said bus controllers
       being a root bus controller for connecting
       said binary tree connected bus controllers
       to said host computer;
       N processing elements, one attached to
       each of said bus controllers;
       N+1 leaf processing elements connected,
       two each, as right and left children to the
       bus controllers at the extremes of said bi-
       nary tree;
       each of said processing elements including
       a microprocessor and a memory;
       each of said bus controllers including, for
       each    processing   element     connected
5                        FIFTH GENERATION   v. INTL BUSINESS


       thereto, a buffered interface connecting
       said processing element to said bus con-
       troller for transmitting instructions and
       data between the bus controller and the
       connected processing element, and means
       for writing information into the memory of
       the connected processing element without
       involving the microprocessor of said con-
       nected processing element.
’024 patent, claim 1 (emphases added).
    The only other independent claim of the ’024 patent,
claim 7, recites a similar system. The ’024 patent cites as
prior art and incorporates by reference two other patents
that are also assigned to Fifth Generation, U.S. Patents
4,843,540 and 4,860,201 to Salvatore Stolfo and Daniel
Miranker (the “’540 and ’201 patents” or the “Stolfo pat-
ents”). Those patents also claim a binary tree computer
system as depicted by Figure 2 in the ’201 patent:
FIFTH GENERATION   v. INTL BUSINESS                      6




    The ’201 patent specification explains that the binary
tree processing system is partitionable “into a number of
subtrees which maintain the full functionality of the
ordinal tree.” ’201 patent, col.10 ll.53-55.     The ’540
patent similarly illustrates the concept of a binary tree
being comprised of sub-binary trees. ’540 patent, col.6 ll.
8-15 (“When functioning independent of its parent ele-
ment the data processing element can act as a root ele-
ment for a sub-binary tree formed by the lower order data
processing elements connected below it.”).
    In October 2008, Fifth Generation brought suit
against IBM in the United States District Court for the
Eastern District of Texas, alleging infringement of the
’240, ’540 and ’201 patents by IBM’s BlueGene supercom-
puter, which is a large-scale parallel computing system.
In March 2009, the case was transferred to the Southern
District of New York, following which Fifth Generation,
7                        FIFTH GENERATION   v. INTL BUSINESS


by joint motion, dropped claims of infringement of the
’540 patent. The court construed claims of the ’240 and
’201 patents in August 2009, as a result of which Fifth
Generation conceded that it could not prove infringement
of the asserted claims by IBM’s system under the district
court’s construction of at least one claim limitation, the
“root bus controller.”
    On January 6, 2010, the court issued a detailed claim
construction opinion, Fifth Generation, 678 F. Supp. 2d
184, and subsequently entered final judgment of nonin-
fringement against Fifth Generation. J.A.1. The court
held that the “root bus controller,” as used in the ’024
claims, connects the binary tree of bus controllers to the
host computer. Fifth Generation, 678 F. Supp. 2d at 201.
The court read the claims to mean that the root bus
controller is necessarily the link between the binary tree
of bus controllers and the host computer. Id. at 202. The
court reasoned that, as such, the root bus controller is the
highest order bus controller and can have no parent bus
controllers. Id. Thus, the court construed the term to
mean “the bus controller at the highest order position of
the binary tree computer system that connects the binary
tree to the host computer and which has no parent bus
controller.” Id. In so holding, the court rejected Fifth
Generation’s argument that any bus controller in the
system can be a root bus controller and that the “binary
tree computer system” of the ’024 patent should be con-
strued broadly to read upon partitionable portions of the
binary tree, such as “subtrees” similar to those disclosed
in the ’201 and ’540 patents. Id.
    Fifth Generation timely appealed the district court’s
final judgment, focusing on the claim construction of that
limitation as well as two other limitations of the ’024
patent claims: “host computer” and “binary tree computer
FIFTH GENERATION   v. INTL BUSINESS                       8


system.”       We have         jurisdiction   pursuant    to
28 U.S.C. § 1295(a)(1).
                        DISCUSSION
                              I.
    We begin with the district court’s construction of the
claim term “root bus controller.” Claim construction is an
issue of law, Markman v. Westview Instruments, Inc., 52
F.3d 967, 977-78 (Fed. Cir. 1995) (en banc), which we
review de novo, Cybor Corp. v. FAS Techs., Inc., 138 F.3d
1448, 1454-55 (Fed. Cir. 1998) (en banc). The words of a
claim are generally given their ordinary and customary
meaning as understood by a person of ordinary skill in the
relevant art at the time of the invention. Phillips v. AWH
Corp., 415 F.3d 1303, 1312-13 (Fed. Cir. 2005) (en banc).
     Fifth Generation argues that the district court erred
in construing “root bus controller” to refer to a controller
at the highest order position of the binary tree computer
system when the specification allows the claims to cover a
system that is partitionable into subsets that are them-
selves binary tree computer systems. Fifth Generation
argues that the ’024 patent specification discloses the
concepts of subtrees and partitionability because it incor-
porates the ’201 and ’540 patents by reference, and those
patents clearly disclose those concepts. According to Fifth
Generation, the district court’s construction violates this
court’s black letter law by requiring that the ’024 patent
specification repeat and expressly describe those concepts
in order for the ’024 patent claims to include them within
their scope. Fifth Generation argues that in light of the
incorporated references, “root bus controller” should
properly be construed to refer to “any bus controller that
is the highest level bus controller in the tree or subtree.”
9                         FIFTH GENERATION   v. INTL BUSINESS


    IBM responds that nothing in the ’024 patent claims
or specification suggests that the concept of partitionabil-
ity disclosed in the earlier patents should be imported
into the ’024 patent claims. IBM points out that the ’024
patent claims never mention the word subtree. On the
contrary, IBM argues, the ’024 patent claims expressly
require that the binary tree system be connected to a host
computer and such a connection would not be possible if
the claims were to be read to apply merely to portions of a
binary tree. Moreover, according to IBM, the ’024 patent
specifically distinguishes itself from the Stolfo patents,
suggesting that architectural concepts from the earlier
patents should not be imported into the ’024 patent
claims.
     We agree with IBM. Patent claims function to deline-
ate the precise scope of a claimed invention and to give
notice to the public, including potential competitors, of the
patentee’s right to exclude. Bicon, Inc. v. Straumann Co.,
441 F.3d 945, 950 (Fed. Cir. 2006); see also Interactive Gift
Express, Inc. v. Compuserve, Inc., 256 F.3d 1323, 1331
(Fed. Cir. 2001) (“In construing claims, the analytical
focus must begin and remain centered on the language of
the claims themselves, for it is that language that the
patentee chose to use to particularly point out and dis-
tinctly claim the subject matter which the patentee re-
gards as his invention.”) (quotation and alterations
omitted). This notice function would be undermined,
however, if courts construed claims so as to render char-
acteristics specifically described in those claims superflu-
ous. Bicon, 441 F.3d at 950. As such, we construe claims
to give effect to all of their terms. Id. Claims 1 and 7 of
the ’024 patent clearly state that the root bus controller is
“for connecting said binary tree connected bus controllers
to said host computer.” In order for the root bus control-
ler to serve as this claimed link between the binary tree of
FIFTH GENERATION   v. INTL BUSINESS                      10


bus controllers and the host computer, it has to be the
highest order bus controller. If the root bus controller
were construed to be capable of having a parent bus
controller, this claim limitation would simply lose its
plain meaning.
    Fifth Generation proposes that the root bus controller
is merely the highest level bus controller of a subtree that
could possibly connect to a parent bus controller as part of
a larger tree. But a plain reading of claims 1 and 7 man-
dates a rejection of that argument. The claims are toward
“[a] binary tree computer system for connection to and
control by a host computer.” ’024 patent, claims 1, 7.
Further, in claiming the bus controllers, the claim lan-
guage specifically requires “one of said bus controllers” to
be the root bus controller. Id. (emphasis added). We are
therefore not persuaded by Fifth Generation’s argument
that requires not only that the root bus controller not
provide the claimed link to the host computer, but also
invalidates the claim requirement that only one of the bus
controllers in the entire claimed system be the root bus
controller.
    Fifth Generation points out that the ’024 patent speci-
fication shows that the root bus controller is connected to
the host computer through the driver and the PCI bus.
See ’024 patent col.2 ll.41-42. Therefore, it argues, the
claims do not require a direct connection between the root
bus controller and the host computer. We reject that
argument as well. The driver and the PCI bus merely
provide the necessary interface that makes the connection
to the host computer possible. Id. at 2:41-42. (“the root
node . . . attaches the tree to the host 13 through a driver
14 an [sic] interface, such as PCI bus 16.”). The presence
of those elements does not in any way suggest that the
inventors envisioned or claimed a system wherein a root
bus controller connected to the host computer through
11                       FIFTH GENERATION   v. INTL BUSINESS


other bus controllers of the binary tree system. On the
contrary, the specification repeatedly suggests a “direct”
connection and supports the plain reading of the claims.
Id. at 2:51-53 (“Each node BCx is connected upstream to a
parent node, except for the root node BC1, which is con-
nected to the host.”); id. at Abstract (“One of the bus
controllers is a root bus controller that connects the
binary tree to the host computer.”); id. at 1:52-53 (“one of
the bus controllers being a root bus controller for connect-
ing the tree to the host computer”). Under Fifth Genera-
tion’s construction, the ’024 claims could potentially read
on any randomly networked group of computer nodes as
long as one bus controller was eventually connected to a
host computer somewhere. We find no basis for that
position.
    Fifth Generation’s proposed broader construction of
the disputed terms relies heavily on its argument that the
’024 patent incorporated the ’201 and ’540 patents by
reference and that a disclosure of subtrees in those earlier
patents supports such a construction. Whether, and to
what extent, material has been incorporated by reference
into a host document, is a question of law that we review
de novo. Adv. Display Sys., Inc. v. Kent State Univ., 212
F.3d 1272, 1283 (Fed. Cir. 2000). We agree with Fifth
Generation that the ’024 patent specification does not
need to expressly recite concepts disclosed in the earlier
Stolfo patents in order to incorporate them into the later
patent specification. The clear incorporation by reference
suffices to serve that purpose here. See Zenon Envtl., Inc.
v. U.S. Filter Corp., 506 F.3d 1370, 1378 (Fed. Cir. 2007)
(“Incorporation by reference provides a method for inte-
grating material from various documents into a host
document . . . by citing such material in a manner that
makes clear that the material is effectively part of the
host document as if it were explicitly contained therein.”)
FIFTH GENERATION   v. INTL BUSINESS                     12


(quotation omitted). To the extent the district court
imposed a contrary requirement by holding that the Stolfo
patents were not incorporated by reference because of the
’024 patent’s criticism of those earlier inventions, Fifth
Generation, 678 F. Supp. 2d at 197, we conclude that it
erred. However, we do not agree with Fifth Generation
that every concept of the prior inventions is necessarily
imported into every claim of the later patent. See Modine
Mfg. Co. v. U.S. Int’l Trade Comm’n, 75 F.3d 1545, 1553
(Fed. Cir. 1996) (“[I]ncorporation by reference does not
convert the invention of the incorporated patent into the
invention of the host patent.”), overruled on other grounds
by Festo Corp. v. Shoketsu Kinzoku Kabushiki Co., Ltd.,
234 F.3d 558 (Fed. Cir. 2000). Here, the ’024 patent
claims are clear in claiming a complete computer system,
including specific functionality of the single root bus
controller within that computer system. In light of such
clear claim language, it is inappropriate to look to the
incorporated references to arrive at a stretched reading of
those claim limitations. Interactive Gift Express, 256 F.3d
at 1331 (“If the claim language is clear on its face, then
our consideration of the rest of the intrinsic evidence is
restricted to determining if a deviation from the clear
language of the claims is specified.”); see also Unique
Concepts, Inc. v. Brown, 939 F.2d 1558, 1563 (Fed. Cir.
1991) (“When the language of a claim is clear, as here,
and a different interpretation would render meaningless
express claim limitations, we do not resort to speculative
interpretation based on claims not granted.”).
    Moreover, the Stolfo patents do not disclose or claim
subtrees that are independently connected to a host
computer in the manner that Fifth Generation would like
the ’024 patent claims to be construed. What is disclosed
and claimed in those patents are subtrees that comprise a
subset of a larger binary tree computer system that, in its
13                        FIFTH GENERATION   v. INTL BUSINESS


entirety, connects to the host computer. The ’201 patent
disclosure relied upon by Fifth Generation as relating to
subtrees recites a plurality of subtrees working together
as part of a larger binary tree system. See, e.g., ’201
patent, claim 9 (“at least two of the sub-trees execute
identical programs on identical data and the results of
such program execution are compared to detect faults in
the sub-trees”). Likewise, the ’540 patent only describes
subtrees that function together in parallel as an integral
part of a larger computer system. See ’540 patent, col.3
ll.49-60 (“It may be noted that one of the characteristics of
the binary tree 20 as illustrated in FIG. 1 is that it in-
cludes sub-sets which are also binary trees. . . . the sub-
binary trees of binary tree may act separately as separate
processing systems acting in parallel.”) (emphases added).
    We also agree with IBM that the Stolfo patents in fact
show that Fifth Generation’s inventor did not claim
independent subtree systems in the ’024 patent in the
manner now proposed by Fifth Generation. Fifth Genera-
tion asserts that the invention claimed in the ’024 patent
was merely an enhancement of the inventions claimed in
the earlier patents assigned to Fifth Generation. There-
fore, under Fifth Generation’s own assertion, at the time
of the filing of the ’024 patent, its inventors had claimed
subtrees, at least as part of a larger binary tree computer
system, in the earlier patents, and yet the ’024 patent
inventor, employed by the same company, did not do so in
the later patent, thereby demonstrating that such sys-
tems are not within the ’024 patent claims’ scope. See
Kara Tech. Inc. v. Stamps.com Inc., 582 F.3d 1341, 1347
(Fed. Cir. 2009) (citing Phillips, 415 F.3d at 1314) (hold-
ing that the claims at issue did not require the use of a
“key” where the inventor had omitted the requirement in
those claims while explicitly reciting it in other claims,
thereby demonstrating an intent to claim a different
FIFTH GENERATION   v. INTL BUSINESS                        14


scope); see also Abbott Labs. v. Sandoz, Inc., 566 F.3d
1282, 1297 (Fed. Cir. 2009) (holding that a chemical
formulation that the applicants could have claimed given
that it appeared in their priority application, but chose
not to, falls outside the scope, literal or equivalent, of the
claim).
    Thus, we conclude that the district court’s construc-
tion of the term “root bus controller” requiring that it be
the highest order bus controller of the binary tree system
was correct. In light of that disposition and the parties’
stipulation below, we do not reach the claim construction
of other disputed claim terms.
                        CONCLUSION
    We have considered Fifth Generation’s remaining ar-
guments and do not find them persuasive. Accordingly,
the judgment of the district court is
                       AFFIRMED.
