        NOTE: This disposition is nonprecedential

  United States Court of Appeals
      for the Federal Circuit
              __________________________

               MICROTHIN.COM, INC.,
                  Plaintiff-Appellant,
                           v.
             SILICONEZONE USA, LLC,
                    Defendant.
              __________________________

                      2010-1079
              __________________________

   Appeal from the United States District Court for the
Northern District of Illinois in case No. 06-CV-1522,
Judge Virginia M. Kendall.
              ___________________________

                 Decided: May 20, 2010
              ___________________________

   JOHN S. LETCHINGER, Wildman, Harrold, Allen &
Dixon LLP, of Chicago, Illinois, for plaintiff-appellant.
With him on the brief was GREGORY M. SMITH.
              __________________________

  Before BRYSON, GAJARSA, and MOORE, Circuit Judges.
MICROTHIN.COM   v. SILICONEZONE USA                        2

PER CURIAM.
    Microthin.com, Inc. (Microthin) sued SiliconeZone
USA, LLC (SiliconeZone) in the United States District
Court for the Northern District of Illinois for infringement
of claims of U.S. Patent No. 5,942,311 (the ’311 patent)
and U.S. Patent No. 5,997,995 (the ’995 patent). The
district court ruled, on summary judgment, that the
claims were invalid as anticipated by U.S. Patent No.
5,738,325 (the Brown patent). Microthin.com, Inc. v.
SiliconeZone USA, LLC, No. 06-CV-1522, 2009 U.S. Dist.
LEXIS 38100 (N.D. Ill. May 6, 2009) (Opinion). The
district court found that Microthin had not asserted
infringement of any other claims, denied Microthin’s
motion to amend its complaint, and dismissed the case.
For the following reasons, we affirm.
                       BACKGROUND
    The ’311 patent claims a thin, non-slip mat or pad
made of plastic. The ’995 patent, a divisional of the ’311
patent, claims a method for making such a mat or pad.
Each patent has one independent claim and several
dependent claims. In the Background Facts section of the
complaint, Microthin stated that “SiliconeZone’s
‘KITCHENZONE’ Cutting Boards are one of Silicone-
Zone’s products which infringe at least Claim 1 of the ’311
patent and the ’995 patent.” J.A. 157. SiliconeZone filed
an answer and counterclaims, including counterclaims for
invalidity and unenforceability of the ’311 and ’995 pat-
ents.
     At the close of fact discovery, SiliconeZone filed a mo-
tion for summary judgment of invalidity of claim 1 of the
’311 and ’995 patents. The district court asked the parties
to file a joint claim construction chart. In the joint claim
construction chart, Microthin offered constructions for all
the claims in both the ’311 and ’995 patents, asserting
that all the claims of the patents had been at issue
3                        MICROTHIN.COM   v. SILICONEZONE USA

throughout the pendency of the case. J.A. 253-66. Sili-
coneZone stated in the chart that Microthin had not
alleged infringement of any dependent claims, and there-
fore SiliconeZone did not offer constructions of any claims
except for claim 1 of each patent. J.A. 253, 261.
    On May 6, 2009, the district court issued a Memoran-
dum Opinion and Order construing disputed terms of
claim 1 of both patents-in-suit. The court then analyzed
claim 1 of each patent in light of the Brown patent and
concluded that in light of its claim construction, there was
no genuine issue of material fact in dispute. Opinion at
15, 17. The district court granted summary judgment of
invalidity of claim 1 of each patent.
    After the district court granted summary judgment of
invalidity in favor of SiliconeZone, the district court asked
the parties to submit position papers to determine if any
asserted claims remained in the case. SiliconeZone’s
position was that Microthin only asserted claim 1 of each
patent and therefore the grant of summary judgment
resolved the case. Microthin argued that the dependent
claims had always been asserted and were still at issue.
The district court determined that Microthin had only
asserted claim 1 of each patent throughout the litigation,
and had not placed any other claims at issue. Because
the dependent claims were not at issue, the district court
construed Microthin’s position paper as a motion for leave
to amend its complaint, which the district court denied.
The district court reasoned that because the parties had
already conducted discovery and prepared dispositive
motions, justice would not be served by permitting Mi-
crothin to amend its complaint.
    Microthin appeals the district court’s grant of sum-
mary judgment of invalidity, arguing that the district
court incorrectly construed the term “non-slip” in claim 1
of both patents. Microthin also appeals the district court’s
MICROTHIN.COM   v. SILICONEZONE USA                         4

denial of its motion to amend its complaint.        We have
jurisdiction pursuant to 35 U.S.C. § 1295(a)(1).
                        DISCUSSION
                              I
    We review a district court’s grant of summary judg-
ment de novo. Revolution Eyewear, Inc. v. Aspex Eyewear,
Inc., 563 F.3d 1358, 1365 (Fed. Cir. 2009). Summary
judgment is appropriate when there is no genuine issue as
to any material fact and the moving party is entitled to
judgment as a matter of law. Fed. R. Civ. P. 56(c). When
determining whether a genuine issue of material fact
exists, we view the evidence in the light most favorable to
the nonmoving party and resolve all doubts in its favor.
Eli Lilly & Co. v. Barr Labs., Inc., 251 F.3d 955, 962-63
(Fed. Cir. 2001). Claim construction is a question of law
that this court reviews de novo. See Cybor Corp. v. FAS
Techs., Inc., 138 F.3d 1448, 1456 (Fed. Cir. 1998) (en
banc). We give claim terms their ordinary and accus-
tomed meaning as understood by one of ordinary skill in
the art. Hockerson-Halberstadt, Inc. v. Avia Group Int’l,
Inc., 222 F.3d 951, 955 (Fed. Cir. 2000). “It is well-settled
that, in interpreting an asserted claim, the court should
look first to the intrinsic evidence of record, i.e., the
patent itself, including the claims, the specification and, if
in evidence, the prosecution history . . . . Such intrinsic
evidence is the most significant source of the legally
operative meaning of disputed claim language.” Vitronics
Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir.
1996).
    Claim 1 of the ’311 patent states:
    A non-slip mat or pad consisting of a transparent
    plastic sheet having an upper surface and a lower
    surface, a coating of one or more inks forming a
    design on the lower surface and adapted to show
5                        MICROTHIN.COM   v. SILICONEZONE USA

    through the plastic sheet to be seen through the
    top surface, and a non-slip coating adhering to the
    lower surface and inked coatings to form a mat or
    pad having a thickness in the range of 1.0 to 30.0
    mils.
’311 patent col.4 l.64-col.5 l.3 (emphasis added). Claim 1
of the ’995 patent states:
    A method for manufacturing a non-slip mat or
    pad, including the steps of providing a mat or pad
    formed of a plastic material, printing a design or
    logo to show on the upper surface of the mat, and
    applying a non-slip surface to the underside of the
    mat or pad with the total thickness of the mat or
    pad in the range of 1.0 to 30.0 mils.
’995 patent col.5 ll.4-9 (emphasis added).
    The district court construed “non-slip” to mean “re-
duces or prevents smooth sliding motion.” Opinion at 7,
12. Microthin challenges the district court’s interpreta-
tion, arguing that “non-slip” means “to reduce or prevent
smooth sliding motion without being sticky to the touch.”
To support its proposed construction, Microthin points to
two places in the specifications where the patents discuss
a non-slip surface that is not sticky to the touch. See ’311
patent col.1 ll.6-10, col.3 ll.3-5; ’995 patent col.1 ll.7-11,
col.3 ll.7-11.
    We agree with the district court that the plain and or-
dinary meaning of “non-slip” is “reduces or prevents
smooth sliding motion” and does not distinguish between
sticky and non-sticky characteristics. Claim 1 in each
patent does not include any limitation suggesting that the
non-slip surface must not be sticky to the touch. More-
over, dependent claim 8 of the ’311 patent adds a single
limitation to claim 1, “wherein the non-slip surface is not
sticky to the touch.” ’311 patent col.6 ll.4-5 (emphasis
added). “[T]he presence of a dependent claim that adds a
MICROTHIN.COM   v. SILICONEZONE USA                         6

particular limitation gives rise to a presumption that the
limitation in question is not present in the independent
claim.” Phillips v. AWH Corp., 415 F.3d 1303, 1315 (Fed.
Cir. 2005) (en banc). In cases such as this, “where the
limitation that is sought to be ‘read into’ an independent
claim already appears in a dependent claim, the doctrine
of claim differentiation is at its strongest.” Liebel-
Flarsheim Co. v. Medrad, Inc., 358 F.3d 898, 910 (Fed.
Cir. 2004). Hence, the claim language fully supports the
district court’s construction.
    Microthin also cites the specification as indicating
that the non-slip surface is not sticky. These statements
do not, however, justify interpreting the term non-slip
different from its plain and ordinary meaning. The
patentee did not, in this case, act as his own lexicographer
defining “non-slip” contrary to its plain and ordinary
meaning. To be his own lexicographer, a patentee must
use a “special definition of the term [that] is clearly stated
in the patent specification or file history.” Vitronics Corp.
v. Conceptronic, Inc., 90 F.3d 1576, 1580 (Fed. Cir. 1996);
see also CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d
1359, 1366 (“[T]he claim term will not receive its ordinary
meaning if the patentee acted as his own lexicographer
and clearly set forth a definition of the disputed claim
term in either the specification or prosecution history.”).
Here, the specification contains no such clear definition of
“non-slip.” The preferred embodiment does indicate that
the non-slip surface is not sticky to the touch. See ’311
patent col.3 ll.1-5; ’995 patent col.3 ll.7-11. Additionally,
in the Technical Field of the patent there is also a men-
tion of the non-slip surface not being sticky. See ’311
patent col.1 ll.4-8 (“The invention disclosed . . . provides
the required frictional characteristics to prevent slipping
upon substantially any surface without being sticky to the
touch.”); ’995 patent col.1 ll.7-11 (same). These refer-
7                       MICROTHIN.COM   v. SILICONEZONE USA

ences, however, do not amount to a clear definition of non-
slip.
      Likewise, the specification and prosecution history do
not present a clear disclaimer such as the patents in
SciMed Life Systems, Inc. v. Advanced Cardiovascular
Systems, 242 F.3d 1337 (Fed. Cir. 2001). We have stated
that “claim terms take on their ordinary and accustomed
meanings unless the patentee demonstrated an intent to
deviate from the ordinary and accustomed meaning of a
claim term by redefining the term or by characterizing the
invention in the intrinsic record using words or expres-
sions of manifest exclusion or restriction, representing a
clear disavowal of claim scope.” Teleflex, Inc. v. Ficosa N.
Am. Corp., 299 F.3d 1313, 1327 (Fed. Cir. 2002). In
SciMed, the patents at issue related to balloon dilatation
catheters containing passageways, or lumens. 242 F.3d at
1339. Only two types of lumen arrangements, dual (or
adjacent) and annular (or coaxial), were known and
practiced in the prior art. Id. Although the asserted
claims did not claim a particular lumen arrangement, see
id. at 1340, we determined that the common specification
of the patents “lead[s] to the inescapable conclusion that
. . . the asserted claims read only on catheters having
coaxial lumens.” Id. at 1342. For example, the abstract
identified the lumen as annular, the written description
distinguished the prior art by discussing the disadvan-
tages of dual lumen configurations, the “Summary of the
Invention” described the invention numerous times as
having an annular lumen, and a section describing pre-
ferred embodiments stated that “all embodiments of the
present invention contemplated and disclosed herein” had
an annular lumen arrangement. Id. at 1342-43. We
stated that “[t]he words ‘all embodiments of the present
invention’ are broad and unequivocal,” and that they
“cannot reasonably be interpreted as limited to the pre-
ferred invention.” Id. at 1344.
MICROTHIN.COM   v. SILICONEZONE USA                       8

     In contrast, in Liebel-Flarsheim, we reversed the dis-
trict court’s construction of claims related to powered
injectors used in medical applications. 358 F.3d at 900.
Although none of the asserted claims expressly referred to
a pressure jacket—a jacket that surrounds a syringe and
prevents it from breaking under pressure from the injec-
tion fluid—the district court concluded that “the specifica-
tion makes clear that the injector includes a pressure
jacket.” Id. at 901 (citation omitted). The Appellee made
several arguments as to why the district court’s construc-
tion was correct: (1) all the embodiments described in the
specification featured pressure jackets, id. at 905; (2) the
abstract described the invention as including a pressure
jacket, id. at 908; (3) the Summary of the Invention
described two objectives of the invention in terms of use
with pressure jackets, id.; and (4) the Summary of the
Invention also described a “principle[] of the present
invention” in terms of use with pressure jackets, id.
Although all the embodiments contained pressure jackets,
we nonetheless determined that “the written description
does not contain a clear disavowal of embodiments lacking
a pressure jacket.” Id. With respect to the language in
the abstract, we stated that it “does not suggest that a
pressure jacket is an essential component of the inven-
tion, nor is there any language in that passage, or else-
where in the specification, that disclaims the use of the
invention in absence of a pressure jacket.” Id.
     The language in the specifications of the ’311 and ’995
patents does not constitute a clear disclaimer of sticky
non-slip surfaces. Here, two statements in the specifica-
tion mention that the non-slip surface is not sticky to the
touch—one in the Technical Field and one in the descrip-
tion of the preferred embodiment. The remainder of the
disclosure describes the non-slip surface as “tacky.” See,
e.g., Abstract, col.2 ll.63-66, col.4 ll.54-60. The term
“tacky” is commonly understood as “sticky to the touch.”
9                        MICROTHIN.COM   v. SILICONEZONE USA

Opinion at 12 (citing Merriam-Webster’s Collegiate Dic-
tionary 1199 (10th ed. 1996)). Nowhere in the specifica-
tion does it suggest that a non-sticky surface is “an
essential component of the invention,” nor does it clearly
disclaim the use of a sticky surface. See Liebel-Flarsheim,
358 F.3d at 908. We conclude that the district court
correctly construed the non-slip limitation by giving it the
plain and ordinary meaning.
    Although anticipation is a question of fact, it may be
decided on summary judgment if there is no genuine
dispute of material fact. Leggett & Platt, Inc. v. VUTEk,
Inc., 537 F.3d 1349, 1352 (Fed. Cir. 2008). Because
Microthin’s appeal of anticipation hinged entirely on our
adoption of its claim construction of non-slip, we affirm
the district court’s grant of summary judgment; claim 1 of
each patent is invalid.
                             II
     The final issue appealed by Microthin is the district
court’s denial of Microthin’s motion to amend its com-
plaint, a procedural issue. “To review a purely procedural
question not pertaining to patent law, . . . this court again
applies the rule of the regional circuit.” Phonometrics,
Inc. v. Hospitality Franchise Sys., 203 F.3d 790, 793 (Fed.
Cir. 2000). The Seventh Circuit reviews a district court’s
denial of a request for leave to amend for abuse of discre-
tion. See Foster v. DeLuca, 545 F.3d 582, 583 (7th Cir.
2008). Under Seventh Circuit law, a district court abuses
its discretion in the denial of a motion for leave to amend
only if the district court “refus[es] to grant the leave
without any justifying reason.” Brunt v. Seiu, 284 F.3d
715, 720 (7th Cir. 2002).
    Microthin argues that even if the independent claims
of the patents are invalid, the district court improperly
terminated the case because all claims of the patents are
at issue. To support its assertion that the dependent
MICROTHIN.COM   v. SILICONEZONE USA                       10

claims are at issue, Microthin points to several places in
its complaint and other documents where it alleged that
SiliconeZone was infringing “the ’995 Patent” or “the ’311
Patent,” as well as statements that SiliconeZone was
infringing “at least” the independent claims. Microthin
also points to its interrogatory answers, where it asserted
that SiliconeZone may have products that infringe other
claims and that Microthin reserved the right to supple-
ment its answer pending further discovery.
      The district court concluded that Microthin never as-
serted dependent claims of the patents during the course
of the case, despite several opportunities to do so. We see
no clear error in the district court’s conclusion. Microthin
identified one allegedly infringing product in its com-
plaint—SiliconeZone’s KitchenZone cutting boards—and
two asserted claims. J.A. 157, 159-60. The addition of the
language “at least” did not constitute the assertion of
additional claims. In SiliconeZone’s first set of interroga-
tories, Microthin was requested to identify “how each
element of each relevant claims [sic] is met by Silicone-
Zone’s product,” and also to “[i]dentify, by specific claim
language, any and all limitations in the claims of the ’311
patent and the ’995 patent, that Microthin asserts Sili-
coneZone’s product falls within.” J.A. 286. Microthin
responded that “SiliconeZone Kitchenzone Cutting Boards
. . . infringe at least Claim 1 of the patents in suit as set
forth below,” and provided a claim chart comparing the
identified cutting boards with claim 1 of the ’311 patent.
J.A. 283. Microthin further stated that “SiliconeZone’s
products are made by the patented process of at least
Claim 1 of the ’995 patent . . . . Discovery is ongoing and
Microthin reserves the right to supplement its answer
pending further discovery.” Id. Although Microthin
reserved the right to supplement its response, it never
did.
11                      MICROTHIN.COM   v. SILICONEZONE USA

    In response to SiliconeZone’s second amended motion
for summary judgment, Microthin stated that “defen-
dant’s products infringe at least claim 1 of each of the
patents-in-suit and may infringe additional dependent
claims, which will be determined at a later date based on
discovery, which has currently been stayed by the Court.”
J.A. 270-71. Similarly, in a reply brief to the court on its
motion to resume discovery, Microthin stated that “De-
fendant’s yet to be discovered products and processes may
very well infringe [the dependent] claims as well. How-
ever, Defendant has not provided the relevant discovery
for Microthin to be able to make this determination.” J.A.
234. At no point did Microthin make any particular
assertions of infringement of any claims other than claim
1. Even on appeal, Microthin does not identify any Sili-
coneZone products that it alleges to infringe any of the
dependent claims of the patents.
    The district court did not abuse its discretion by deny-
ing Microthin leave to amend its complaint in order to
remedy its failure to identify other asserted claims. The
district court determined that because discovery was
complete at the time of Microthin’s motion and dispositive
motions had been prepared, justice would not be served by
granting Microthin’s motion. Further, as discussed above,
the district court noted that Microthin had failed to
previously amend its complaint despite prior opportuni-
ties to do so.
    Microthin disputes that discovery was closed in the
case, citing to the district court’s striking of the case
schedule on December 7, 2006. The district court had
ordered that fact discovery be closed by December 6, 2006.
Hence, at the time the district court struck the case
schedule, fact discovery had in fact concluded. In a hear-
ing on April 10, 2007, the district court decided to reopen
discovery only as it related to invalidity, not to infringe-
ment. We see no abuse of discretion in the district court’s
MICROTHIN.COM   v. SILICONEZONE USA                    12

decision not to extend discovery to allow Microthin to
attempt to find evidence to possibly support additional
allegations of infringement.
                       CONCLUSION
    For the foregoing reasons, we affirm the issues on ap-
peal.
                       AFFIRMED
