       NOTE: This disposition is nonprecedential.


  United States Court of Appeals
      for the Federal Circuit
                ______________________

  SECURE WEB CONFERENCE CORPORATION,
             Plaintiff-Appellant

                           v.

           MICROSOFT CORPORATION,
               Defendant-Appellee

                  LOGITECH INC.,
                      Defendant
                ______________________

                      2015-1321
                ______________________

   Appeal from the United States District Court for the
Eastern District of New York in No. 2:13-cv-02642-JG-
AKT, Judge John Gleeson.
                ______________________

              Decided: February 17, 2016
               ______________________

    WAYNE MICHAEL HELGE, Davidson Berquist Jackson
& Gowdey, LLP, McLean, VA, argued for plaintiff-
appellant. Also represented by JAMES DANIEL BERQUIST,
Arlington, VA; JONATHAN TAD SUDER, Friedman, Suder &
Cooke, Fort Worth, TX.
2         SECURE WEB CONFERENCE CORP.     v. MICROSOFT CORP.



    CHAD J. PETERMAN, Patterson Belknap Webb & Tyler
LLP, New York, NY, argued for defendant-appellee. Also
represented by WILLIAM F. CAVANAUGH, JR.
                ______________________

    Before LOURIE, BRYSON, and STOLL, Circuit Judges.
STOLL, Circuit Judge.
    Secure Web Conference Corporation (“Secure Web”)
appeals the district court’s construction of several patent
claim terms in a patent infringement lawsuit it initiated
against Microsoft Corporation (“Microsoft”). Secure Web
argues that the district court improperly imported limita-
tions from specific embodiments into the challenged
constructions. Because the district court correctly con-
strued the terms at issue by considering the language of
the claims themselves and by looking to the patent speci-
fication for guidance on claim term meaning, we affirm.
                        BACKGROUND
     Secure Web owns U.S. Patent Nos. 6,856,686 (“ ’686
patent”) and 6,856,687 (“ ’687 patent”), which are both
directed to providing a method and system for enabling
encryption of data in a manner that provides increased
security. ’686 patent, col. 1, ll. 50–51; ’687 patent, col. 1
ll. 34–41. The patents differ little. The ’686 patent,
issued on February 15, 2005, describes a method for
securing communications between two microprocessor
devices, such as between two telephones, fax machines,
and/or computers. The patent describes achieving se-
cured communications through the use of a “security
device,” which has encryption and decryption capabilities
and interfaces with each of the microprocessor devices.
Figure 1 depicts the system at a high level.
SECURE WEB CONFERENCE CORP.   v. MICROSOFT CORP.            3




    Exemplary claim 1, with the term at issue in this ap-
peal italicized, recites:
    1. A method for exchanging data between a plu-
    rality of microprocessor based devices over a com-
    puter network so as to frustrate unauthorized
    access to said data, said method comprising:
       providing a plurality of security devices each
    being associated with at least one of said plurality
    of microprocessor based devices;
       establishing a point-to-point electronic com-
    munications session between a first of said securi-
    ty devices being associated with a first of said
    microprocessor based devices and a second of said
    security devices being associated with a second of
    said microprocessor based devices;
       exchanging security data between said first
    and second security devices using said point-to-
    point communications session;
        encrypting data to be transmitted using said
    first security device and said security data; and,
4           SECURE WEB CONFERENCE CORP.   v. MICROSOFT CORP.



        transmitting said encrypted data from said
    first microprocessor based device to said second
    microprocessor based device over said computer
    network.
’686 patent col. 14 ll. 40–61.
    The ’687 patent issued on February 15, 2005 as a con-
tinuation-in-part of the application that became the ’686
patent. The ’687 patent further claims a security device
operable on both wired and wireless networks and with
varying network bandwidths. Claim 29, with the terms at
issue in this appeal italicized, is the only asserted claim
from the ’687 patent:
    29. A device for providing secure communications
    over a network comprising:
          a communication port for transfer of audio da-
    ta;
        a plurality of communication ports for transfer
    of digital data;
          a keypad;
          an encoding/decoding device;
       a conversion device operable to convert be-
    tween audio and digital data;
       a processor, in communication with a memory,
    said keypad and said encoding/decoding device,
    operable to execute code for:
        selecting a configuration of a transmission and
    a reception port from among said communication
    ports dependent upon the presence of a network
    communication device and an input/output device
    in communication with said selected ports;
SECURE WEB CONFERENCE CORP.       v. MICROSOFT CORP.       5



        providing data received from said selected re-
    ception port to said encryption/decryption device
    for encrypting; and
       providing said encrypted data to said selected
    transmission port.
’668 patent col. 10 l. 58 – col. 12 l. 6.
     Secure Web sued Microsoft in the United States Dis-
trict Court for the Eastern District of New York, accusing
Microsoft’s Skype and Lync products of infringing the
asserted claims of the ’686 and ’687 patents. The district
court entered a claim construction order largely in Mi-
crosoft’s favor, at which point the parties stipulated to a
judgment of noninfringement. The stipulation provides
that, for each patent, each of the appealed claim construc-
tions constitutes a separate and independent ground for
noninfringement, both literally and under the doctrine of
equivalents.
    Secure Web timely appealed, and we have jurisdiction
to review under 28 U.S.C. § 1295(a)(1).
                          DISCUSSION
    The “ultimate interpretation” of a claim term, as well
as interpretations of “evidence intrinsic to the patent (the
patent claims and specifications, along with the patent’s
prosecution history),” are legal conclusions, which this
court reviews de novo. Teva Pharm. USA, Inc. v. Sandoz,
Inc., 135 S. Ct. 831, 841 (2015). Where a district court
“make[s] factual findings about . . . extrinsic evidence[,
however,] th[e] subsidiary factfinding must be reviewed
for clear error on appeal.” Id. Because the district court
relied only on intrinsic evidence in this case, our review is
de novo.
                         I. ’686 Patent
    The district court construed the claim term “security
device” as “a stand-alone telecommunications device,
6         SECURE WEB CONFERENCE CORP.    v. MICROSOFT CORP.



external to and separate from the associated microproces-
sor based or electronic device, capable of encrypting and
decrypting data.” Secure Web Conference Corp. v. Mi-
crosoft Corp., No. 13-CV-2642, 2014 WL 4954644, at *2–5
(E.D.N.Y. Oct. 2, 2014) (Dist. Ct. Op.) (emphases added).
Secure Web disputes that a person of ordinary skill in the
art, having considered the intrinsic record, would under-
stand that a security device is limited to “stand-alone”
devices that are “external to and separate from” the
underlying microprocessor based device(s).
    Claim construction seeks to ascribe the “ordinary and
customary meaning” to claim terms as they would be
understood to a person of ordinary skill in the art at the
time of invention. Phillips v. AWH Corp., 415 F.3d 1303,
1312–14 (Fed. Cir. 2005) (en banc) (citing Vitronics Corp.
v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)).
“[T]he claims themselves provide substantial guidance as
to the meaning of particular claim terms,” id. at 1314, and
therefore “the context of the surrounding words of the
claim also must be considered in determining the ordi-
nary and customary meaning of those terms,” ACTV, Inc.
v. Walt Disney Co., 346 F.3d 1082, 1088 (Fed. Cir. 2003).
But “the person of ordinary skill in the art is deemed to
read the claim term not only in the context of the particu-
lar claim in which the disputed term appears, but in the
context of the entire patent, including the specification.”
Phillips, 415 F.3d at 1313. Indeed, the specification is
“the single best guide to the meaning of a disputed term”
and “[u]sually, it is dispositive.” Id. Thus, “claims ‘must
be read in view of the specification, of which they are a
part.’” Id. at 1315 (quoting Markman v. Westview In-
struments, Inc., 52 F.3d 967, 979 (Fed. Cir. 1995) (en
banc), aff’d, 517 U.S. 370 (1996)).
    Applying those principles here, we conclude that one
of ordinary skill in the art reading the specification would
have understood a security device to be a stand-alone
device that is separate from and external to the associated
SECURE WEB CONFERENCE CORP.     v. MICROSOFT CORP.           7



microprocessor device(s). All descriptions of the security
device in the intrinsic record are limited to a stand-alone
device. Nothing in the intrinsic record suggests that the
patentee intended a broader notion of a security device.
Significantly, at no point does the specification contem-
plate a security device embedded within a microprocessor-
based device. To the contrary, the specification touts the
separate and stand-alone nature of the security device as
an advantage.
     First, the Background of the Invention section charac-
terizes the security device as an add-on component to
existing microprocessor-based devices, explaining that “as
many users already possess telephones, facsimile ma-
chines and computers, it is desirable to provide a security
device capable of performing [security] functions in con-
nection with these existing devices.” ’686 patent col. 1
ll. 43–48. The remainder of the specification reinforces
that using a stand-alone security device is not mere
happenstance.
     For example, in an embodiment where the micropro-
cessor-based device is a computer, the specification ex-
plains that separating the security device from the
microprocessor-based device advantageously allows a user
to secure data residing in the microprocessor-based device
in the event it is lost or stolen. Explaining how the sepa-
rate security device will store a decryption key needed to
decipher messages, the specification notes that “separa-
tion of the [security] device 10 from the computer 40 acts
as a means of securing data residing in the computer 40.”
Id. col. 10 l. 67 – col. 11 l. 2. Continuing, the specification
explains that a user “could instruct computer 40 to
transmit a file to the [security] device 10 for encryption
with the permanent key” and the “encrypted file would
then be re-transmitted back to the computer.” Id. col. 11
ll. 4–6. “In this way, even if the computer 40 becomes lost
or stolen, unauthorized access to the encrypted file could
still be frustrated by adequately safeguarding device 10.”
8         SECURE WEB CONFERENCE CORP.     v. MICROSOFT CORP.



Id. col. 11 ll. 12–15. This benefit is derived directly from
the separation of the security device and the computer.
    Not only does the specification describe specific ad-
vantages gained from separating the security device from
the microprocessor-based device, but also it never once
suggests embedding the security device within the micro-
processor-based device. Figure 1 of the ’686 patent illus-
trates the system described by the patent and clearly
depicts the security device separate from and external to
the microprocessor-based devices connecting to it. Fig-
ure 2 provides a detailed view of the security device itself.
Figure 2 shows, and the associated text describes, several
sets of input/output ports on the security device so that
various microprocessor-based devices may become “cou-
pled” to it. Id. Fig. 2 and col. 3 ll. 8–34. Figure 2 and its
associated text also indicate that the security device has
its own microcontroller. Id. The existence of ports for
interfacing with other devices and the use of an independ-
ent microcontroller exhibit the level of self-sufficiency
expected of a stand-alone device.
    We are mindful not to limit claims to preferred em-
bodiments, but in this case, the district court did not err
in concluding that Figures 1 and 2 depict the essence of
the claimed invention rather than a preferred embodi-
ment. Particularly, the specification describes Figure 1 as
depicting “a communication system according to the
present invention” and Figure 2 as depicting “a telecom-
munications security device according to the instant
invention.” Id. col. 2 ll. 16–19. While the specification
later describes Figure 2 as “a block diagram of a preferred
form of the security device according to the instant inven-
tion” (Id. col. 3 ll. 7–9), this statement does not change the
understanding of “security device” at least because the
specification repeatedly notes the importance of using an
external security device, reinforcing that the security
device of the invention is limited to stand-alone security
devices. See Toro Co. v. White Consol. Indus., 199 F.3d
SECURE WEB CONFERENCE CORP.    v. MICROSOFT CORP.           9



1295, 1300–01 (Fed. Cir. 1999) (construing claim to re-
quire a particular configuration where specification
described the importance of the configuration and did not
disclose others).
    Microsoft presented the district court with dictionary
definitions of the word “device.” Secure Web argues these
definitions led the district court astray, despite recogniz-
ing that “the district court did not expressly cite to or rely
on Microsoft’s dictionary definitions in its Order.” Appel-
lant Br. 25. This argument is unpersuasive, as the intrin-
sic record alone wholly supports the district court’s
construction. Therefore, we, like the district court, do not
rely on dictionary definitions to reach our construction.
See Phillips, 415 F.3d 1303, 1318 (Fed. Cir. 2005) (citing
Markman, 52 F.3d at 980) (indicating that use of extrinsic
evidence in claim construction is permissive, not manda-
tory); Virnetx, Inc. v. Cisco Sys., Inc., 767 F.3d 1308, 1316
(Fed. Cir. 2014) (“Although courts are permitted to con-
sider extrinsic evidence like expert testimony, dictionar-
ies, and treatises, such evidence is generally of less
significance than the intrinsic record.”).
    Even were we to rely on dictionaries in this case, we
would not likely find the definition of “device” useful
because our construction does not hinge on the word
“device” used in isolation. See IGT v. Bally Gaming Int’l,
Inc., 659 F.3d 1109, 1117 (Fed. Cir. 2011) (“Extracting a
single word from a claim divorced from the surrounding
limitations can lead construction astray. Claim language
must be construed in the claim in which it appears.”). For
this same reason, we are also unconvinced by Secure
Web’s argument that because Figure 2 depicts an “encryp-
tion/decryption device” embedded within the security
device, an inference can be drawn that the patentee used
the term “device” throughout the patent to mean a com-
ponent capable of being embedded. This attenuated
argument does not overcome the specification’s consistent
10        SECURE WEB CONFERENCE CORP.   v. MICROSOFT CORP.



treatment of the actual term-in-dispute—“security de-
vice”—as a separate, stand-alone device.
    In sum, a person of ordinary skill in the art having
considered the intrinsic record would have understood the
term security device to describe a stand-alone, external
device that is separate from the underlying microproces-
sor device(s). Therefore, the district court did not err in
construing “security device.”
    The parties stipulated to a final judgment of nonin-
fringement of the ’686 patent under the construction of
“security device” adopted by the district court. Because
we adopt the district court’s construction of “security
device,” we do not address the construction underlying the
alternative stipulated ground for noninfringement as we
need not decide more than is necessary to dispose of the
case regarding to the ’686 patent. See Network Com-
merce, Inc. v. Microsoft Corp., 422 F.3d 1353, 1357 n.3
(Fed. Cir. 2005) (declining to construe claim term when
noninfringement judgment is affirmed on other claim
construction ground).
                     II. ’687 Patent
    The claim construction dispute for the related ’687 pa-
tent concerns not the security device, but the network
communication and input/output devices, which are the
devices with which the security device interfaces. Never-
theless, the heart of the dispute remains the same:
whether the security device and the interfacing devices
must be separate from and external to one another.
    The district court determined that the devices needed
to be separate and external, construing the ’687 claim
term “network communications device” as “a separate,
external device, connected via a communications port on
the ‘device for providing secure communications over a
network,’ that allows for communications over the net-
work” and the term “input/output device” as “a separate,
SECURE WEB CONFERENCE CORP.    v. MICROSOFT CORP.         11



external device, connected via a communications port on
the ‘device for providing secure communications over a
network,’ that inputs data into and receives data from the
device.” Dist. Ct. Op., 2014 WL 4954644, at *7–8 (empha-
ses added). Similar to its argument for the “security
device” term in the ’686 patent, Secure Web disputes that
a person of ordinary skill in the art would recognize a
“separate, external” limitation for these devices.
     The constructions the district court reached for the
terms “network communication device” and “input/output
device” have considerable support, particularly from the
language of the ’687 patent’s sole asserted claim, claim 29.
As noted, “the claims themselves provide substantial
guidance as to the meaning of particular claim terms. . . .
the context in which a term is used in the asserted claim
can be highly instructive.” Phillips, 415 F.3d at 1314
(citing Vitronics, 90 F.3d at 1582; ACTV, 346 F.3d at
1088). Here, asserted claim 29 recites that the security
device contains “a plurality of communication ports for
the transfer of digital data.” ’687 patent col. 10 ll. 61–62.
The security device also contains a processor used for
“selecting a configuration of a transmission and a recep-
tion port from among said communication ports dependent
upon the presence of a network communication device and
an input/output device in communication with said
selected ports.” Id. col. 11 ll. 4–8 (emphases added).
Thus, the claim is drawn to a security device that differ-
ent devices can be connected to or disconnected from,
resulting in a configuration change of the security device.
    If the network communication device and in-
put/output device were not separate from the security
device, this capability would be unnecessary; the security
device would not need to determine whether a network
communication device or input/output device was present
because they always would be. Instead, the claim lan-
guage makes clear that the network configuration device
and input/output device are, as the district court ex-
12        SECURE WEB CONFERENCE CORP.     v. MICROSOFT CORP.



plained, “only contingently present.” Dist. Ct. Op., 2014
WL 4954644, at *13. This is to say that the devices are
separate from and external to one another. We are not
convinced by Secure Web’s argument that the “in commu-
nication with selected ports” limitation somehow cuts
against this inference.
     Beyond support from claim 29, the ’687 patent specifi-
cation provides additional support for the district court’s
construction, similar to that found for the security device
construction in the ’686 patent. For example, the specifi-
cation describes that the security device is “portable,”
which is made possible by use of a battery. ’687 patent
col. 4 ll. 59–63; see also id. col. 1 ll. 37, 55. The logical
import of this description is that the security device and
the devices with which it interfaces must be separate so
that the security device remains portable. And, as with
the ’686 patent, the ’687 patent figures and associated
descriptions consistently depict and describe the security
device as separate from and external to the network
communication device and the input/output device.
    Based on the intrinsic evidence, we conclude that the
district court correctly construed “network communica-
tions device” and “input/output device.” Per the stipulat-
ed final judgment entered by the parties, each of these
constructions is a ground for noninfringement of the ’687
patent for Microsoft.
                       CONCLUSION
    For the foregoing reasons, we affirm the district
court’s entry of stipulated judgment of noninfringement.
                       AFFIRMED
