  United States Court of Appeals
      for the Federal Circuit
              __________________________

             TOSHIBA CORPORATION,
                Plaintiff-Appellant,
                           v.
   IMATION CORP., MOSER BAER INDIA LTD.,
           GLYPHICS MEDIA, INC.,
    CMC MAGNETICS CORP., HOTAN CORP.,
           KHYPERMEDIA CORP.,
   RITEK CORP., AND ADVANCED MEDIA, INC.,
             Defendants-Appellees.
              __________________________

                      2011-1204
              __________________________

   Appeal from the United States District Court for the
Western District of Wisconsin in case no. 09-CV-0305,
Magistrate Judge Stephen L. Crocker.
             ___________________________

                Decided: June 11, 2012
             ___________________________

    DEANNE E. MAYNARD, Morrison & Foerster LLP, of
Washington, DC, argued for plaintiff-appellant. With her
on the brief were G. BRIAN BUSEY, BRIAN R. MATSUI, MARC
A. HEARRON and ADAM A. ELTOUKHY; and KARL J.
KRAMER, of Palo Alto, California.
TOSHIBA CORP   v. IMATION CORP                            2


   ALAN D. SMITH, Fish & Richardson P.C., of Boston,
Massachusetts, argued for defendants-appellees. With
him on the brief were CHRISTOPHER DILLON, STEPHEN A.
MARSHALL, SAMUEL SHERRY and MAUREEN M. BRENNER.
              __________________________

    Before DYK, SCHALL, and MOORE, Circuit Judges.
  Opinion for the court filed by Circuit Judge MOORE.
Opinion concurring-in-part and dissenting-in-part filed by
                  Circuit Judge DYK.
MOORE, Circuit Judge.
    Toshiba Corporation accused Imation Corporation et
al. (collectively, Appellees) of infringing claims of U.S.
Patent nos. 5,892,751 (’751 patent) and 5,831,966 (’966
patent) relating to optical disc technology. The district
court granted summary judgment of non-infringement for
the asserted claims under both patents except for a de
minimis claim of direct infringement that was later
dismissed. For the reasons set forth below, we affirm-in-
part and vacate-in-part the grant of summary judgment of
non-infringement and remand.
                        BACKGROUND
    DVDs are optical discs used to store data or digital
content such as movies. DVDs are made in several for-
mats, which are governed by technical standards that
allow for compatibility among DVD players and recorders.
Appellees manufacture or sell recordable blank DVDs
that comply with these standards. The DVD standards
generally organize a disc into three areas: a “lead-in area”
which contains information about the DVD’s structure
and properties; a “data area” where data is recorded and
stored; and a “lead-out area” which indicates the func-
tional end of the data area. E.g., J.A. 2356.
3                             TOSHIBA CORP   v. IMATION CORP


    There are two methods to record data onto DVDs:
disc-at-once mode and multisession mode. The disc-at-
once mode writes all of the data to the disc in a single
session, including the lead-in area containing a test
pattern and the lead-out area. Multisession mode allows
a user to record some data in one session and then later
record additional data to the DVD in another session.
Once a user records all of the data on the DVD, the user
may choose to “finalize” the DVD, which writes the test
pattern in the lead-in area and writes the lead-out area.
Prior to finalization, the DVD does not contain the test
pattern or the lead-out area. The district court identified
as an undisputed fact that a recordable DVD “can be
played in the drive in which it was recorded without
finalization, but not on other recorders or conventional
DVD players.” Toshiba Corp. v. Imation Corp., No. 09-cv-
305-slc, slip op. at 13 (W.D. Wis. Dec. 28, 2010). A final-
ized DVD, however, can be played on any standardized
DVD player or drive.
    Toshiba accused Appellees of infringing claims of the
’751 and ’966 patents. Appellees moved for summary
judgment that they did not indirectly infringe the ’751
patent. The district court granted the motion, concluding
that the use of unfinalized DVDs was a substantial non-
infringing use. The court held that “[b]oth theories of
‘indirect infringement’ – that is, contributory and induc-
ing infringement – fail if there are any ‘substantial’ non-
infringing uses.” Toshiba Corp., No. 09-cv-305-slc, slip op.
at 25-26 (citing Dynacore Holdings Corp. v. U.S. Phillips
Corp., 363 F.3d 1263, 1275 (Fed. Cir. 2004)).
    Appellees also moved for summary judgment that
they did not infringe the ’966 patent. Asserted claim 1 of
the ’966 patent requires that the lead-in area contain
information identifying the structure of the recording
medium. The district court construed terms of claim 1 to
TOSHIBA CORP   v. IMATION CORP                           4


require that such information have the purpose of identi-
fying information for the entire recording medium. To-
shiba Corp., No. 09-cv-305-slc, slip op. at 22. Because the
district court held that the identifying information on the
accused DVDs did not have the purpose of providing
information for the entire recording medium, the court
granted summary judgment of non-infringement as to the
’966 patent. Id. at *22, 24.
    The parties stipulated to dismissal of the remaining
de minimis claim of direct infringement. J.A. 22246.
Toshiba appeals from the district court’s grant of sum-
mary judgment of non-infringement for both patents and
its construction of certain ’966 patent claim terms. We
have jurisdiction under 28 U.S.C. § 1295(a)(1).
                            DISCUSSION
    We review a district court’s grant of summary judg-
ment de novo. Fujitsu Ltd. v. Netgear Inc., 620 F.3d 1321,
1325 (Fed. Cir. 2010). Summary judgment is appropriate
when, drawing all justifiable inferences in the non-
movant’s favor, there exists no genuine issue of material
fact and the movant is entitled to judgment as a matter of
law. Fed. R. Civ. P. 56; Anderson v. Liberty Lobby, Inc.,
477 U.S. 242, 255 (1986). A dispute about a material fact
is genuine “if the evidence is such that a reasonable jury
could return a verdict for the nonmoving party.” Ander-
son, 477 U.S. at 248.
                       I.    ’751 Patent
    The ’751 patent is directed to how data is written onto
DVDs. The claims of the ’751 patent, like the DVD stan-
dards, require a lead-in area, data area, and lead-out
area. E.g., ’751 patent cl.1. The asserted claims also
require that the optical discs (e.g., DVDs) have a test
pattern included in the lead-in area. Id. DVD players
5                             TOSHIBA CORP   v. IMATION CORP


may use the test pattern to ensure data is read properly
from the DVD, and to make adjustments if not. Id. ab-
stract & col.2 ll.34-44. The test pattern and the lead-out
area are only written when the disc is recorded in disc-at-
once mode or finalized; unfinalized DVDs do not contain
the test pattern or the lead-out area. Toshiba does not
dispute that unfinalized DVDs do not infringe the ’751
patent. See Appellant’s Br. 10.
    The district court concluded “the evidence establishes
that recording DVDs without finalizing them is a non-
infringing use, and there is no evidence that this use is
not substantial.” Toshiba Corp., No. 09-cv-305-slc, slip op.
at 26. The district court noted that there is evidence of a
“commonsensical and efficient” reason not to finalize a
disc: a user may continue recording new material on the
disc, and as long as the user keeps the disc in the same
machine, the user can read all of the recorded material
without finalizing the disc. Id. at *27. The court also
noted that although manuals and other marketing mate-
rials recommended finalizing DVDs, they do not suggest
that finalization is the only proper way to use DVDs or
that use of unfinalized DVDs is “aberrant” or “occasional.”
Id. at *28. The materials, according to the district court,
simply explain that finalization is required for using
DVDs in a different recorder or player. Id. Finally, the
court noted that Toshiba failed to introduce evidence
showing that playback in other recorders or players is a
use preferred over playback in the same DVD recorder,
which does not require finalization. Id. The district court
thus held that Toshiba failed to introduce any evidence to
create a genuine issue of material fact that using unfinal-
ized DVDs is not a substantial non-infringing use. Id. at
*29.
    The court granted summary judgment of non-
infringement for Toshiba’s contributory and induced
TOSHIBA CORP   v. IMATION CORP                             6


infringement allegations, holding that both infringement
theories “fail if there are any ‘substantial’ non-infringing
uses.” Id. at *26, 30. Toshiba appeals the ruling that
there is a substantial non-infringing use and that a
substantial non-infringing use precludes liability for
induced infringement.
               A. Contributory Infringement

     To establish contributory infringement liability, the
patent owner must show, among other things, that there
are no substantial non-infringing uses.          35 U.S.C.
§ 271(c). “[N]on-infringing uses are substantial when
they are not unusual, far-fetched, illusory, impractical,
occasional, aberrant, or experimental.” Vita-Mix Corp. v.
Basic Holding, Inc., 581 F.3d 1317, 1327 (Fed. Cir. 2009).
In assessing whether a use is substantial, the fact-finder
may consider “the use’s frequency, . . . the use’s practical-
ity, the invention’s intended purpose, and the intended
market.” i4i Ltd. P’ship v. Microsoft Corp., 598 F.3d 831,
851 (Fed. Cir. 2010).
     Toshiba argues that the intended use of DVDs is the
long-term storage of data that may be accessed on any
industry-standard DVD player or recorder, and that
Appellees instruct their users that finalization is neces-
sary to accomplish this. Appellant’s Br. 29, 31-33. For
example, the accused DVDs are advertised as compliant
with industry standards, which, according to Toshiba,
require that the DVDs be finalized. Id. at 30-31. Toshiba
contends that unfinalized DVDs recorded in multisession
mode are merely an interim step in the process of re-
cording data, and that finalization is necessary to achieve
the intended result. Id. at 35. Toshiba argues that the
use of unfinalized DVDs is “unintended” and “impracti-
cal,” and thus not substantial.
7                             TOSHIBA CORP   v. IMATION CORP


    Appellees contend there is no evidence that the re-
cording and playing of unfinalized DVDs is not a substan-
tial non-infringing use. Appellees’ Br. 41. Appellees
argue that the evidence shows that users choose not to
finalize the DVDs so that they can continue recording
data to the disc and that the standards support the use of
unfinalized DVDs. Id. at 42-43. Appellees also argue
there are good reasons not to finalize: finalization pre-
vents users from adding more data; it takes time; and it is
not necessary in order to use the DVD in the device in
which it was recorded. Id. at 43. Appellees claim that
even if it were true that they recommended finalizing
DVDs, recommending an infringing use (finalizing) is not
evidence that the non-infringing use is not substantial.
Id. at 44. Appellees note that Toshiba has no admissible
expert testimony regarding unfinalized DVDs, no end
user testimony regarding the use of unfinalized DVDs,
and no documents or other evidence showing that the use
of unfinalized DVDs is unusual, far-fetched, illusory,
impractical, occasional, aberrant, or experimental. Id. at
43-44. Appellees thus argue Toshiba failed to create a
genuine issue of fact whether the use of unfinalized DVDs
constitutes a substantial non-infringing use.
    We agree with Appellees that Toshiba failed to proffer
evidence that creates a genuine issue of material fact.
Because Toshiba had the burden to prove the lack of
substantial non-infringing uses, Toshiba was required to
put forth evidence showing that the use of unfinalized
DVDs was not substantial. See Golden Blount, Inc. v.
Robert H. Peterson Co., 438 F.3d 1354, 1363 (Fed. Cir.
2006). There is, however, insufficient evidence in the
record to create a genuine issue of fact. Toshiba does not
contest that unfinalized DVDs do not infringe. Toshiba
admits that users may record data on the accused DVDs
without ever finalizing the DVDs, and that such DVDs
TOSHIBA CORP   v. IMATION CORP                            8


may be read in the recorder in which the data was writ-
ten. Appellant’s Br. 10. Toshiba presented no survey,
expert, or other evidence showing how frequently users
choose not to finalize DVDs. Toshiba did not introduce
evidence showing that using unfinalized DVDs is “un-
usual, far-fetched, illusory, impractical, occasional, aber-
rant, or experimental.” See Vita-Mix, 581 F.3d at 1327.
Toshiba cites the DVD standards, which it claims require
finalization, but even the DVD standards recognize that
users may record to DVDs without finalization. See, e.g.,
Ecma Int’l, Standard ECMA-359, at 75 (1st ed. 2004) (J.A.
2378) (identifying disc status bits indicating the disc was
recorded in multisession mode and is unfinalized). To-
shiba did not introduce evidence showing how often users
will later finalize the DVDs, thereby making the use of
unfinalized DVDs an interim step. The evidence Toshiba
cites merely shows that it is recommended that users
finalize their DVDs. Recommending one use over another
does not mean the non-recommended use is not substan-
tial. Moreover, even Toshiba’s own user manual provides
evidence that users may also choose not to finalize DVDs
because it is a laborious process. See Toshiba, DVD Video
Recorder DR430KU: Owner’s Manual, at 8 (2010) (J.A.
12979). Toshiba had the burden of proof, but failed to
introduce evidence sufficient to create a genuine issue of
material fact as to whether using unfinalized DVDs was
not a substantial non-infringing use. Therefore, the
district court did not err in granting summary judgment
of no contributory infringement.
                 B. Induced Infringement

    “Whoever actively induces infringement of a patent
shall be liable as an infringer.” 35 U.S.C. § 271(b). To
prove induced infringement, the patentee “must show
direct infringement, and that the alleged infringer ‘know-
9                              TOSHIBA CORP   v. IMATION CORP


ingly induced infringement and possessed specific intent
to encourage another’s infringement.’” i4i, 598 F.3d at
851 (quoting MEMC Elec. Materials, Inc. v. Mitsubishi
Materials Silicon Corp., 420 F.3d 1369, 1378 (Fed. Cir.
2005)).
     The district court held that the existence of a substan-
tial non-infringing use precludes a finding of induced
infringement. See Toshiba Corp., No. 09-cv-305-slc, slip
op. at 26. The court stated that “[b]oth theories of ‘indi-
rect infringement’ – that is, contributory and inducing
infringement – fail if there are any ‘substantial’ non-
infringing uses.” Id. The district court erred as a matter
of law. The existence of a substantial non-infringing use
does not preclude a finding of inducement. Erbe Elek-
tromedizin GmbH v. Canaday Tech. LLC, 629 F.3d 1278,
1284 (Fed. Cir. 2010). Appellees attempt to recast the
district court’s error by suggesting it was “directed at the
theory Toshiba advanced in this case, and is not a general
statement of the law of inducement.” Appellees’ Br. 36.
The district court’s opinion, however, is clear on its face
and contains no language suggesting its statement was
anything other than a general statement of the law.
Toshiba Corp., No. 09-cv-305-slc, slip op. at 26.
    Appellees alternatively argue that we should affirm
the grant of summary judgment of no inducement because
Toshiba introduced no evidence of direct infringement.
Appellees’ Br. 34. Direct infringement is a required
element to establish induced infringement. i4i, 598 F.3d
at 851. Appellees argue that Toshiba failed to create a
genuine issue of material fact as to whether users directly
infringed the ’751 patent. See id. To satisfy the direct
infringement requirement, the patentee “must either
point to specific instances of direct infringement or show
that the accused device necessarily infringes the patent in
suit.” ACCO Brands, Inc. v. ABA Locks Mfr. Co., 501 F.3d
TOSHIBA CORP   v. IMATION CORP                          10


1307, 1313 (Fed. Cir. 2007) (citing Dynacore, 363 F.3d at
1275-76). Appellees argue that because users must
choose either to use the disc-at-once mode or to finalize
the disc in order to infringe, Toshiba must come forward
with evidence of specific instances of infringement. See
Appellees’ Br. 34. Appellees contend that the record
shows that the “only person who ever finalized a disc was
Toshiba’s expert.” Id. at 35.
    We conclude that it would not be correct to affirm on
this alternative basis. There is sufficient evidence to
create a genuine issue of material fact. “Direct infringe-
ment can be proven by circumstantial evidence.” Vita-
Mix, 581 F.3d at 1326 (citing Moleculon Research Corp. v.
CBS, Inc., 793 F.2d 1261, 1272 (Fed. Cir. 1986)); see also
Alco Standard Corp v. Tenn. Valley Auth., 808 F.2d 1490,
1503 (Fed. Cir. 1986) (“Although the evidence of in-
fringement is circumstantial, that does not make it any
less credible or persuasive.”). Circumstantial evidence
must show that at least one person directly infringed an
asserted claim during the relevant time period. See
Lucent Techs., Inc. v. Gateway, Inc., 580 F.3d 1301, 1317
(Fed. Cir. 2009) (“[A] finding of infringement can rest on
as little as one instance of the claimed method being
performed during the pertinent time period.”).
    The claims at issue require discs to have a lead-in
area, data area, and lead-out area, wherein the lead-in
area includes a test pattern. E.g., ’751 patent cl.1. Users
may record data onto DVDs using either the disc-at-once
mode or multisession mode. Every time a user selects the
disc-at-once mode to record data, the DVD infringes
because the disc-at-once mode automatically writes the
lead-in area with the test pattern, the data area, and the
lead-out area. The disc-at-once mode does not contain a
separate finalization option. Thus, when the disc-at-once
mode is used, the DVD necessarily infringes. Users
11                             TOSHIBA CORP   v. IMATION CORP


alternatively may record DVDs in multisession mode. In
multisession mode, users have the option to record some
data but not finalize the DVD, in which case the recorder
does not write the test pattern or the lead-out area. If a
user chooses not to finalize a DVD, however, only the
recorder that wrote the DVD will be able to play or read
from the DVD. To ensure the DVD is readable by other
recorders or players, a user must finalize the DVD.
    Although some users may use multisession mode and
choose not to finalize, such use is contrary to Appellees’
instructions to users that they must finalize the DVDs to
ensure compatibility. E.g., J.A. 12850 (“Discs must be
finalized for playback in DVD players.”). Some materials
even recommended against using multisession mode –
which allows a user not to finalize the DVD – stating,
“For the best compatibility with Data [DVDs], do not use
the multisession option.” J.A. 12805, 13164. Appellees
also designed the DVDs to comply with the standards,
which provide that a DVD “shall” be divided into three
areas: a lead-in area, a data area, and a lead-out area.
E.g., Ecma Int’l, Standard ECMA-359, at 53 (J.A. 2356).
The lead-out area is only written when the disc is final-
ized or written in the disc-at-once mode. The purpose of
the DVD standards is to provide compatibility among
various disc drives, which requires using the disc-at-once
mode or finalizing the DVDs. See, e.g., J.A. 3696. In light
of all of the evidence in the record regarding why someone
would finalize or use the disc-at-once mode, we hold there
is enough to preclude summary judgment of non-
infringement.
    This is not the first time we have concluded that
where an alleged infringer designs a product for use in an
infringing way and instructs users to use the product in
an infringing way, there is sufficient evidence for a jury to
find direct infringement. For example in Lucent, like in
TOSHIBA CORP   v. IMATION CORP                            12


this case, the accused infringer designed its products to
practice the claimed invention and instructed its custom-
ers to use the accused product in an infringing way. 580
F.3d at 1318. We held that this was sufficient to support
the jury’s verdict that someone other than Lucent’s expert
used the product in an infringing way. Id. Similar to
Lucent, Appellees designed the DVDs to be used in an
infringing way and instructed users to use them in the
infringing way by finalizing the DVDs or using the disc-
at-once mode. This is sufficient to preclude summary
judgment.
    Appellees contend this case is more like Fujitsu and
ACCO. Argument at 17:05-17:55, 20:00-20:25, Toshiba
Corp. v. Imation Corp., No. 2011-1204, available at
http://oralarguments.cafc.uscourts.gov/default.aspx?fl=20
11-1204.mp3; Appellees’ Br. 34. In Fujitsu, the accused
products would infringe only when a user chose an option
in the accused software. 620 F.3d at 1328. Unlike this
case, however, the infringing option in Fujitsu was dis-
abled by default, and the relevant standard and user
manuals simply described how to use the product in an
infringing manner. Id. We held that the evidence in
Fujitsu showed that the device was “capable of” infringing
but did not suggest that users actually used it in an
infringing way. Id. at 1329. In the present case, however,
recording DVDs in disc-at-once mode or multisession
mode with finalization is not disabled by default, and
Appellees go beyond describing the infringing mode; they
recommended that customers use the infringing mode.
Further, the DVD standards require a lead-out area,
which is only written when the disc is finalized or written
using the disc-at-once mode. Thus, the evidence in this
case goes beyond showing that the accused DVDs are
“capable of” infringing; the evidence is sufficient to create
13                            TOSHIBA CORP   v. IMATION CORP


a genuine issue of material fact, thus precluding summary
judgment.
    ACCO also involved an accused product that was “ca-
pable of” infringing. 501 F.3d at 1313-14. In ACCO, there
were instructions describing the infringing use and differ-
ent instructions describing the non-infringing use. Id. at
1312-13. The products in ACCO, however, were sold only
with instructions describing the non-infringing use. Id. at
1313. The only other evidence relied on by the patentee
in ACCO was its expert testimony that the infringing
mode was the “natural and intuitive way” to operate the
device. Id. ACCO’s expert, however, “had no opinion” on
whether others used the device in an infringing mode. Id.
Unlike the situation in ACCO, Appellees recommended
that their users use the DVDs in the infringing mode.
Some materials even recommended against using the non-
infringing mode. Toshiba also presented evidence con-
cerning industry standards, and expert evidence that
compliance with such standards is “a commercial neces-
sity.” See J.A. 5034-35 (“It is necessary, and expected by
the marketplace, that the discs within a particular format
comply with the standards so that they can be used
interchangeably.”); see also Appellant’s Br. 30-31. Again,
the evidence in this case shows more than the fact that
the accused DVDs are merely “capable of” infringing.
    We hold there is sufficient evidence such that a “jury
in the present case could . . . reasonably conclude[] that,
sometime during the relevant period . . . more likely than
not one person somewhere in the United States” finalized
DVDs or used the disc-at-once mode. See Lucent, 580
F.3d at 1318. Appellees designed their DVDs to comply
with the DVD standards, instructed users to use them in
an infringing manner, and some recommended against
using the DVDs in a non-infringing manner. Appellees
also advertised their DVDs as compliant with the indus-
TOSHIBA CORP   v. IMATION CORP                          14


try standards. To satisfy the purpose of the standards
(compatibility), the DVDs must be finalized or written
using the disc-at-once mode. This is sufficient evidence to
create a triable issue of fact of whether users finalized
DVDs or used the disc-at-once mode.
    On appeal, Appellees ask us to reach additional issues
not addressed by the district court. We leave it to the
district court to reach those issues in the first instance.
                       II. ’966 Patent
    Toshiba appeals the district court’s grant of summary
judgment of non-infringement and its construction of two
terms in claim 1 of the ’966 patent. We review claim
construction de novo. Cybor Corp. v. FAS Techs., Inc., 138
F.3d 1448, 1455-56 (Fed. Cir. 1998) (en banc). The words
of a claim are generally given their ordinary and custom-
ary meaning as understood by a person of ordinary skill
in the art when read in the context of the specification
and prosecution history. Phillips v. AWH Corp., 415 F.3d
1303, 1313 (Fed. Cir. 2005) (en banc).
    The ’966 patent describes a recording medium (e.g., a
DVD) containing a “management region” with informa-
tion about the structure of the medium. ’966 patent at
[57]. DVDs may be one-sided or two-sided, meaning data
can be recorded on only one side or on both sides. A DVD
may also have one or more layers on a single side for
recording data. The DVD standards require the lead-in
area of DVDs to include data that indicate the number of
layers on the current side of the disc (via bits b5 and b6)
and identify the current layer (via bit b24). E.g., J.A.
3707, 3712. Claim 1 requires that the disc provide identi-
fying information for the medium:
       A recording medium comprising:
15                            TOSHIBA CORP   v. IMATION CORP


     at least one recording plane, wherein each re-
        cording plane on which data is recorded in-
        cludes:
        a data region in which data is recorded; and
        a management region including number-of-
          recording planes identifying information
          that represents the number of recording
          planes of the recording medium and re-
          cording-plane identifying information that
          uniquely identifies that recording plane.
’966 patent cl.1 (emphasis added). The district court
construed the “number-of-recording planes identifying
information” to mean “information whose purpose is to
identify the number of recording planes on the recording
medium.” Toshiba Corp., No. 09-cv-305-slc, slip op. at 22.
The court construed the “recording-plane identifying
information that uniquely identifies that recording plane”
as “information whose purpose is to identify the recording
plane being reproduced.” Id.
    Toshiba accused only single-sided DVDs of infringing
the ’966 patent. In single sided DVDs, there are recording
planes on only one side of the disc. As a result, the num-
ber of planes on the single side is also the number of
planes on the medium as a whole. The accused DVDs
comply with the standards by providing the identifying
information via bits b5, b6, and b24. Toshiba alleged that
bits b5 and b6 meet the “number-of-recording planes”
limitation because they identify the number of layers on
the medium (since they are single-sided discs), and that
bit b24 meets the “recording-plane identifying informa-
tion.”
    Because the purpose of the bits (b5, b6, and b24) on
the accused devices was to identify information for only
TOSHIBA CORP   v. IMATION CORP                             16


one side of the disc, the district court held that they do not
serve the purpose of identifying information for the disc
as a whole, and thus do not infringe. Id. at *24. The
court recognized that the bits on the accused discs provide
identifying information as to the entire medium, but
reasoned that “the purpose of the bits on the accused
products is merely to identify the number of planes and
the recording plane on a given side of a disc,” not the
entire medium. Id. at *23-24. The court stated, “[t]he
fact that the bits on the accused discs happen to have the
same information as they would if the standards properly
distinguished two-sided discs does not establish that
these bits satisfy the required claim elements.” Id.
    Toshiba appeals the district court’s construction, ar-
guing that the court improperly read a “purpose” re-
quirement into claim 1. Appellant’s Br. 37. Toshiba
contends that each limitation should have been given its
plain and ordinary meaning, as recited in the claim itself.
Id. at 38. The plain meaning, according to Toshiba,
simply requires that the identifying information represent
the number of (or identity of) the planes on the medium
regardless of any particular purpose or intent. Id. at 39.
Toshiba also argues that the district court’s construction
improperly imported a limitation from the specification
into the claim. Id. at 43. Toshiba contends that depend-
ent claims 3 and 5 captured the disc side requirements
discussed in the specification and prosecution history. Id.
at 43-46. Toshiba notes that “planes,” as recited in claim
1, are not the same as “sides.” Id. at 48. Toshiba thus
argues the district court erred in granting summary
judgment of non-infringement based on an erroneous
construction.
    Appellees argue that the district court properly con-
strued the terms and that the court’s inclusion of the word
“purpose” did not read a limitation into the claim. Appel-
17                            TOSHIBA CORP   v. IMATION CORP


lees’ Br. 53, 58. Appellees contend that it was inserted to
resolve a dispute as to whether the claim requires that
the information be intended to convey the number of (or
identity of) the recording planes on the medium, or
whether it is sufficient that the information “coinciden-
tally” corresponds to the number of (or identity of) the
planes on the medium. Id. at 58. Appellees argue that
the language of the claims, the specification, and the
prosecution history explain that the purpose of the limita-
tions is to identify information as to the entire medium.
Id. at 53-56. Because the identifying information on the
accused single-sided discs does not have the purpose of
providing information as to the entire medium, Appellees
contend they do not infringe. Id. at 59-63.
    We agree with Toshiba that the district court improp-
erly read a “purpose” requirement into claim 1. The plain
language of the claim requires that the number-of-
recording planes identifying information “represents the
number of recording planes of the recording medium.”
’966 patent cl.1 (emphasis added). Similarly, the claim
requires that the recording-plane identifying information
“uniquely identifies that recording plane.” Id. The lan-
guage of the claim only requires that the information
“represents” the number of recording planes or “uniquely
identifies” the recording plane. These are structural
limitations. There is no dispute that the accused single-
sided, single-layer DVDs have these structural elements.
The district court expressly acknowledged that the ac-
cused devices did have these structural elements. To-
shiba Corp., No. 09-cv-305-slc, slip op. at 24 (“The fact
that the bits on the accused discs happen to have the
same information as they would if the standards properly
distinguished two-sided discs does not establish that
these bits satisfy the required claim elements.”); see also
id. at *22-23 (“Plaintiff continues to contend that defen-
TOSHIBA CORP   v. IMATION CORP                            18


dants’ single-sided, single layer discs meet the claim
language because these discs indicate the total number of
planes on the disc (one) and which plane is reproduced
(the only one). However, as defendants point out, even
though this may be literally true, it is only because plain-
tiff has carefully circumscribed the accused products to
those where a single side of the disc is the entire disc.”).
Bits b5 and b6 on the accused DVDs accurately represent
that the DVDs have one recording plane. Bit b24 on these
DVDs uniquely identifies that the recording plane is the
DVD’s single recording plane. Appellees do not dispute
the fact that these bits accurately reflect that the accused
single-sided, single-layer DVDs contain one recording
plane. See Appellees’ Br. 57-58.
     Appellees argue that these facts are insufficient be-
cause the patent contemplates two-sided discs. For
example, Appellees cite to figure 2 in the specification and
to the prosecution history, both of which refer to multi-
sided discs. Appellees’ Br. 54-56. Figure 2 describes a
“number-of-disc-sides identifier” and a “disc side identi-
fier.” ’966 patent fig.2. The number-of-disc-sides identi-
fier “represents whether the disc is a double-sided disc or
a single-sided disc,” and the disc side identifier indicates
which side of a double-sided disc is being reproduced.
’966 patent col.6 ll.25-28. The prosecution history also
refers to the number-of-disc-sides identifying information.
J.A. 761-62 (“It is clear that this information must be
provided on each side of the disc – i.e., each recording
plane – in order for the disc side identifier 3 to serve its
purpose of identifying which side is being re-
corded/reproduced.” (emphasis added)).
    Claim 1, however, is not limited to multi-sided discs,
but instead is written more broadly. The number-of-disc-
sides identifier and disc side identifier are not limitations
in claim 1. The plain language of claim 1, which is writ-
19                             TOSHIBA CORP   v. IMATION CORP


ten in terms of “planes,” is distinct and different from the
number of (or identity of) the disc sides disclosed in the
specification. This is especially clear in light of dependent
claim 5, which adds an additional requirement of indicat-
ing the number of disc sides. Claim 5 recites:
     The recording medium as in claim 1, wherein: the
     number-of-recording-planes identifying informa-
     tion indicates that the recording medium is one of
     a single-sided disc and a double-sided disc.
’966 patent cl.5. Claim 1 is not so limited. Appellees
cannot overcome the plain meaning of claim 1 by pointing
to an embodiment disclosed in the specification or prose-
cution history. CCS Fitness, Inc. v. Brunswick Corp., 288
F.3d 1359, 1366 (Fed. Cir. 2002) (An accused infringer
cannot overcome the plain meaning of a claim term “sim-
ply by pointing to the preferred embodiment or other
structures or steps disclosed in the specification or prose-
cution history.”). It is “not enough that the only embodi-
ments, or all of the embodiments, contain a particular
limitation.” Thorner v. Sony Computer Entm’t Am. LLC,
669 F.3d 1362, 1366 (Fed. Cir. 2012); see also CCS Fit-
ness, 288 F.3d at 1366 (“[O]ur case law makes clear that a
patentee need not ‘describe in the specification every
conceivable and possible future embodiment of his inven-
tion.’” (citation omitted)). We do not read limitations from
the specification into claims.
    Appellees do not argue that there was a disclaimer
limiting the scope of claim 1. Appellees also do not argue
that the patentee acted as its own lexicographer. Absent
disclaimer or lexicography, the plain meaning of the claim
controls. Thorner, 669 F.3d at 1365 (There are “two
exceptions” to the general rule that the plain meaning of
the claim controls: “1) when a patentee sets out a defini-
tion and acts as his own lexicographer, or 2) when the
TOSHIBA CORP   v. IMATION CORP                          20


patentee disavows the full scope of a claim term either in
the specification or during prosecution.” (citing Vitronics
Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1580 (Fed. Cir.
1996))). This is not a case where the number of recording
planes necessarily pre-supposes two-sided discs. The
claim is broad enough to read on both single-sided and
double-sided discs.
     Toshiba accused only single-sided, single-layer DVDs
of infringing claim 1. The identifying information in an
accused single-sided, single-layer DVD “represents” and
“uniquely identifies” information as to the entire disc.
“[A]pparatus claims cover what a device is, not what a
device does.” Paragon Solutions, LLC v. Timex Corp., 566
F.3d 1075, 1090 (Fed. Cir. 2009) (quoting Hewlett-
Packard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1468
(Fed. Cir. 1990)). We thus reject Appellees’ arguments
that the accused DVDs do not infringe because the identi-
fying information in the DVDs do not have the “purpose”
of identifying information as to the entire medium.
    The dissent suggests that the majority’s construction,
Appellant’s construction, Appellees’ construction, and the
district court’s construction are all in error, and instead
argues for a completely different construction of its own.
The dissent argues that the “number-of-recording planes”
limitation in claim 1 requires identifying both the number
of disc sides and the number of layers per side. Dissent
Op. at 2. The Appellant’s and Appellees’ dispute concerns
whether the limitations must have the “purpose” of identi-
fying information as to the entire medium. Both parties
reject the notion that claim 1 requires differentiation
between one-sided and two-sided discs. Appellant’s Br.
43; Appellees’ Br. 65-67. Appellees, who defend the
district court’s construction on appeal, specifically argue
that the district court’s construction does not contain any
such requirement, stating: “nowhere in the [district
21                             TOSHIBA CORP   v. IMATION CORP


court’s] claim construction order is there a statement or
even a suggestion that the terms in claim 1 require identi-
fying whether the recording medium is single-sided or
double-sided.” Appellees’ Br. 65; see also Appellees’ Br. 65
(“Nothing in these constructions relates to the sides of the
medium.”); Appellees’ Br. 66 (“[T]here is nothing in the
court’s decision that limits Claim 1 to sides. The court’s
orders simply state that the identifiers have to account for
all recording planes on the medium.”); Appellees’ Br. 66
(arguing that the district court’s summary judgment
decision clarifies that “the ‘purpose’ of the bits is to iden-
tify the number of recording planes on the medium – and
not to differentiate between single-sided and double-sided
discs”); Appellees’ Br. 67 (“The [district] court did not
construe Claim 1 as requiring differentiation between
single-sided and double-sided discs.”). Neither party has
ever argued for the dissent’s construction.
     The dissent makes three main arguments in support
of its construction: 1) that the references to disc sides in
the specification and prosecution history show that an
ordinary artisan would interpret “number-of-recording
planes identifying information” to require identifying both
the number of recording layers and the number of disc
sides, 2) that the applicant equated a “recording plane” to
“a side of the disc” to overcome a 35 U.S.C. § 112 rejection
during prosecution, and 3) that the principles of claim
differentiation do not support a different result because
dependent claim 5 narrows claim 1 by covering only
embodiments with one layer per side. Dissent Op. at 2-5.
We address each argument in turn.
    First, as explained above, the number-of-recording
planes limitation in claim 1 only requires “information
that represents the number of recording planes of the
recording medium.” ’966 patent cl.1. Identifying the
number of planes on a recording medium does not require
TOSHIBA CORP   v. IMATION CORP                              22


identifying the number of disc sides. It is not enough that
the only embodiment in the specification describes identi-
fying disc sides. See Thorner, 669 F.3d at 1366. Claim 1
recites “planes,” not “disc sides.” The dissent’s proposed
construction improperly reads in a limitation from the
specification. Dependent claim 5 captures the additional
number-of-disc-sides identifier limitation. ’966 patent
cl.5. Claim 1, the only asserted claim, does not require
indicating the number of disc sides.
   With regard to the dissent’s second argument, to over-
come a 35 U.S.C. § 112 rejection during prosecution, the
applicant explained:
   As illustrated in FIG. 2 and described in the
   Specification at 12-13 a number-of-disc-sides iden-
   tifier 2 and a disc side identifier 3 are recorded in
   . . . the disc. It is clear that this information must
   be provided on each side of the disc – i.e., each re-
   cording plane – in order for the disc side identifier
   3 to serve its purpose of identifying which side is
   being recorded/reproduced.
J.A. 761-62 (citations omitted). A statement in the prose-
cution history can only amount to disclaimer if the appli-
cant “clearly and unambiguously” disavowed claim scope.
3M Innovative Props. Co. v. Avery Dennison Corp., 350
F.3d 1365, 1370-71 (Fed. Cir. 2003) (citations omitted).
This language is not a clear and unambiguous disavowal
of claim scope. When the applicant stated “each side of
the disc – i.e., each recording plane,” the applicant was
merely explaining that in the example in figure 2, a side
of the disc constitutes a recording plane. It does not
follow that a recording plane is to be equated with a disc
side in all instances or that a number of recording planes
identifier must also indicate the number of disc sides. In
fact, two weeks after the applicant made this statement,
23                              TOSHIBA CORP   v. IMATION CORP


the examiner’s statement of reasons for allowance shows
that the examiner did not interpret this statement as
limiting recording planes to disc sides. The examiner
stated:
     [N]one of the cited prior art shows . . . a disk hav-
     ing at least one recording plane . . . and a man-
     agement region including the number of recording
     planes identifying the number of recording planes
     on the disk and a separate recording plane identi-
     fying information that uniquely identify that re-
     cording plane (such as side A or side B or upper
     surface or lower surface).
J.A. 756 (emphasis added). The dissent claims that this
shows that the examiner viewed the “number-of-recording
planes identifying information” to require identification of
the number of sides as well as the number of surfaces (i.e.,
layers) on each side. Dissent Op. at 4. The dissent,
however, mischaracterizes the examiner’s statement. The
examiner stated that recording plane identifying informa-
tion may indicate “side A or side B or upper surface or
lower surface.” J.A. 756 (emphasis added). Had the
examiner understood that identifying both were required,
the examiner would have used “and” rather than “or.”
Instead, this language shows that the examiner under-
stood that recording plane identifying information is not
limited to identifying disc sides.
    Finally, the dissent argues that claim differentiation
does not support a different result. The dissent incor-
rectly concludes that claim 5 narrows claim 1 by covering
only embodiments with one layer per side. Dissent Op. at
5. In our view, this construction is at odds with the plain
language of claim 5. In addition, it has not been advo-
cated by any party. Claim 5 recites:
TOSHIBA CORP   v. IMATION CORP                           24


   The recording medium as in claim 1, wherein: the
   number-of-recording-planes identifying informa-
   tion indicates that the recording medium is one of
   a single-sided disc and a double-sided disc.
’966 patent cl.5. Claim 5 narrows claim 1 by additionally
requiring identification of the number of disc sides. Claim
5 thus covers discs with identifying information that
indicates both the number of planes on the medium and
the number of sides. The prosecution history shows that
the applicant added claim 5 “in order to claim further
aspects of the invention,” namely to add a limitation
“indicating whether the recording medium is a single-
sided or a double-sided disc.” J.A. 1380; see also J.A. 1380
(“The ability to determine which side of the disc that a
recording layer is on facilitates reproduction because, for
example, if a recording plane on side A of a double-sided
disc is to be reproduced, the apparatus can determine
which side of the disc is side A.”). This limitation is not
present in claim 1.
    In sum, claim 1 does not require identifying the num-
ber of disc sides nor does it require that the identifying
information have the purpose of providing information for
the whole disc. We thus hold that the district court erred
in its construction of both claim terms and in granting
summary judgment of non-infringement.
                        CONCLUSION
    The district court correctly granted summary judg-
ment of non-infringement as to contributory infringement
of the asserted claims of the ’751 patent. However, the
court erred in granting summary judgment of non-
infringement as to induced infringement of the asserted
claims of the ’751 patent and in granting summary judg-
ment of non-infringement of claim 1 of the ’966 patent
based on an erroneous claim construction. We therefore
25                              TOSHIBA CORP   v. IMATION CORP


affirm-in-part, vacate-in-part, and remand to the district
court for further proceedings consistent with this opinion.
     AFFIRMED-IN-PART, VACATED-IN-PART, and
                  REMANDED
                           COSTS
     Costs to Plaintiff-Appellant.
  United States Court of Appeals
      for the Federal Circuit
               __________________________

              TOSHIBA CORPORATION,
                 Plaintiff-Appellant,
                            v.
   IMATION CORP., MOSER BAER INDIA LTD.,
           GLYPHICS MEDIA, INC.,
    CMC MAGNETICS CORP., HOTAN CORP.,
           KHYPERMEDIA CORP.,
   RITEK CORP., AND ADVANCED MEDIA, INC.,
             Defendants-Appellees.
               __________________________

                       2011-1204
               __________________________

   Appeal from the United States District Court for the
Western District of Wisconsin in case no. 09-CV-0305,
Magistrate Judge Stephen L. Crocker.
              __________________________

DYK, Circuit Judge, concurring in part and dissenting in
part.
    Although I join the majority opinion on the issues of
contributory and induced infringement with respect to the
’751 patent, I respectfully dissent as to the claim con-
struction and infringement analysis for claim 1 of the ’966
patent.
   Claim 1 of the ’966 patent covers:
   1. A recording medium comprising:
TOSHIBA CORP   v. IMATION CORP                            2


       at least one recording plane, wherein each
       recording plane on which data is recorded
       includes:
       a data region in which data is recorded; and
       a management region including number-
       of-recording-planes identifying informa-
       tion that represents the number of re-
       cording planes of the recording medium
       and recording-plane identifying informa-
       tion that uniquely identifies that re-
       cording plane.
’966 patent col.1 ll.21-29 (filed Sept. 5, 1996) (emphasis
added). As I discuss below, the specification and the
prosecution history of the ’966 patent make clear that the
central objective of the patent was to identify whether an
optical disc was a one-sided disc or a two-sided disc.
While claim 1 is broadly written so that it requires both a
number-of-sides identifier and a number-of-layers per side
identifier (i.e., whether the disc has one or two layers per
side), the accused product here does not have a number of
sides identifier and thus does not infringe.
    First, repeated and consistent references to disc sides
in the specification and the prosecution history clearly
show that “number-of-recording-planes identifying infor-
mation” requires the identification of disc sides.
    When describing the shortcomings of the prior art, the
specification stated that “conventional management
information does not include information that distin-
guishes” between “single-sided discs” and “double-sided
discs.” ’966 patent col.1 ll.22-27. Improving upon the
prior art, an “object of the present invention [wa]s to
provide a recording medium and a reproducing apparatus
thereof that determine the number of recording sides and
3                              TOSHIBA CORP   v. IMATION CORP


a recording surface thereof.” ’966 patent col.2 ll.11-14.
“Thus, according to the present invention, different types
of recording mediums that are for example single-sided
type and double-sided type can be handled.” ’966 patent
col.3 ll.1-3.
     The embodiment illustrated in Figure 2 refers to a
“number-of-disc-sides identifier” and a “disc side identi-
fier.” ’966 patent fig.2. As shown in Figure 2, “[t]he
number-of-disc-sides identifier 2 represents whether the
disc is a double-sided disc or a single-sided disc.” ’966
patent col.6 ll.25-26. Figure 2 and its accompanying text
are the only references in the specification for the terms
“number-of-recording-planes identifying information” and
“recording-plane identifying information,” and thus
inform the meaning that an ordinary artisan would attach
to those terms. There is no relevant embodiment in the
specification that does not have a number-of-disc-sides
identifier, nor any description of such an embodiment.
    Any doubt left by the specification as to the proper
construction of the disputed terms is resolved by the
prosecution history. In addition to prior art rejections
under 35 U.S.C. § 102, the examiner also rejected all
pending claims under § 112 in the last office action prior
to allowance. The examiner stated, among other things,
that “[t]he specification as originally filed does not provide
support for the limitation ‘each recording plane . . . num-
ber of recording plane . . . planes identifying information.’”
J.A. 761 (second and third alterations in original). In
response to the § 112 rejection, Toshiba showed support
for the claimed “number-of-recording planes identifying
information” by equating a “recording plane” to a “side of
the disc”:
    As illustrated in FIG. 2 and as described in the
    Specification . . . a number-of-disc-sides identifier
TOSHIBA CORP   v. IMATION CORP                              4


    2 and a disc side identifier 3 . . . must be provided
    on each side of the disc—i.e., each recording
    plane—in order for the disc side identifier 3 to
    serve its purpose of identifying which side is being
    recorded/reproduced.
J.A. 761-62 (emphasis added). The examiner subse-
quently allowed the claims. In the reasons for allowance,
the examiner stated that:
    [N]one of the cited prior art shows . . . a disk hav-
    ing at least one recording plane . . . and a man-
    agement region including the number of recording
    planes identifying the number of recording planes
    on the disk and a separate recording plane identi-
    fying information that uniquely identify that re-
    cording plane (such as side A or side B or upper
    surface or lower surface)
J.A. 756. Given the examiner’s withdrawal of the § 112
rejection and the stated reasons for allowance, it is clear
that the examiner viewed “number-of-recording-planes
identifying information” as including both a number of
sides identifier and a number of layers per side identifier.
The majority suggests that the examiner’s use of “or” in
the parenthetical shows that identification of disc sides is
not necessarily required. But Toshiba’s representation is
explicit that the number of recording planes identifying
information must identify the number of sides and the
number of layers on a side. The examiner’s statement as
to the recording plane identifying information does noth-
ing to alter that meaning.
    Given the repeated references in the specification to
disc sides and the prosecution history, including the
examiner’s finding that the identification of recording
planes “such as side A or side B or upper surface or lower
surface” is what distinguishes the prior art, it is clear that
5                             TOSHIBA CORP   v. IMATION CORP


“number-of-recording-planes identifying information”
requires the identification of the number of sides as well
as the number of surfaces (i.e., layers) on each side. Thus,
it is not sufficient that the “number-of-recording-planes
identifying information” only identify the number of
layers on a disc just because the disc happens to be a one-
sided disc.     Rather, the “number-of-recording-planes
identifying information” has to identify whether the disc
is a one-sided disc or a two-sided disc.
    The principles of claim differentiation do not support
a different result. The majority appears to suggest that, if
a side identifier is required by claim 1, then claim 5 is
adding something that is already within claim 1, and that
the claims would then have the same scope. However, the
majority fails to recognize that claim 5 narrows claim 1 by
covering only embodiments with one layer per side. Here,
claim 5 recites:
    5. The recording medium as in claim 1, wherein:
       the number-of-recording-planes identifying in-
       formation indicates that the recording me-
       dium is one of a single-sided disc and a
       double-sided disc.
’966 patent col.16 ll.59-62. Whereas claim 1 can cover
embodiments with any number of layers on a side, de-
pendent claim 5 appears to cover only embodiments with
one layer per side. In such embodiments, the identifica-
tion of the number of sides necessarily identifies the
number of recording planes on a disc. In any event, “the
doctrine of claim differentiation does not allow unre-
strained expansion of claims beyond the description of the
invention in the specification, and explanations and
representations made to the PTO in order to obtain al-
lowance of the claims.” Tandon Corp. v. U.S. Int’l Trade
Comm’n, 831 F.2d 1017, 1028 (Fed. Cir. 1987).
TOSHIBA CORP   v. IMATION CORP                           6


    While I agree that appellees’ argument in this case
regarding the correct claim construction is confusing, this
court is not bound by the parties’ views of the proper
claim construction. Exxon Chem. Patents Inc. v. Lubrizol
Corp., 64 F.3d 1553, 1556 (Fed. Cir. 1995). As described
above, the specification and the prosecution history, as
well as the language of claim 1 itself, clearly establish
that claim 1 requires that an accused DVD be able to
identify whether the DVD has one recording side or two
recording sides.
    For these reasons, I would affirm the district court’s
grant of summary judgment of non-infringement of the
’966 patent.
