  United States Court of Appeals
      for the Federal Circuit
                ______________________

  POLARA ENGINEERING INC, A CALIFORNIA
              CORPORATION,
           Plaintiff-Cross-Appellant

                           v.

        CAMPBELL COMPANY, AN IDAHO
               CORPORATION,
              Defendant-Appellant
             ______________________

                 2017-1974, 2017-2033
                ______________________

   Appeals from the United States District Court for the
Central District of California in No. 8:13-cv-00007-DFM,
Magistrate Judge Douglas F. McCormick.
                 ______________________

                Decided: July 10, 2018
                ______________________

   NATHANIEL L. DILGER, One LLP, Newport Beach, CA,
argued for plaintiff-cross-appellant.

    CHRISTOPHER T. HOLLAND, Holland Law LLP, San
Francisco, CA, argued for defendant-appellant. Also
represented by LORI HOLLAND.
                ______________________

   Before LOURIE, DYK, and HUGHES, Circuit Judges.
2            POLARA ENGINEERING INC   v. CAMPBELL COMPANY



LOURIE, Circuit Judge.
     Campbell Company (“Campbell”) appeals from the fi-
nal judgment of the United States District Court for the
Central District of California entering judgment in favor
of Polara Engineering Inc. (“Polara”) on its claim for
infringement of claims 1–4 (“the asserted claims”) of U.S.
Patent 7,145,476 (“the ’476 patent”) and its decision,
following a jury trial, denying Campbell’s post-trial mo-
tions for judgment as a matter of law of invalidity and no
willfulness, and granting Polara’s motion to enhance the
damages award. See Polara Eng’g, Inc. v. Campbell Co.,
237 F. Supp. 3d 956 (C.D. Cal. 2017) (“Post-trial Motions
Opinion”); Judgment, Polara Eng’g, Inc. v. Campbell Co.,
No. SACV-13-00007 (C.D. Cal. Mar. 31, 2017), ECF No.
499 (J.A. 83–84). For the following reasons, we affirm in
part, vacate in part, and remand. 1
                      BACKGROUND
                            I
    Polara, a manufacturer of accessible pedestrian signal
systems (“APS”) and pedestrian push buttons, owns the
’476 patent. Polara originally entered the APS market
with an eight-wire system called the Navigator. Because
many intersections only have two wires, installation of
eight-wire systems like the Navigator could be difficult
and labor-intensive. In about late 2000 or early 2001,
Polara engineers Leslie Beckwith and Randy Cruz, the
named inventors listed on the ’476 patent, began design-
ing a two-wire version of the Navigator. Their work led to
the ’476 patent.


    1   Although Polara noticed a cross-appeal from cer-
tain determinations of the district court, it has not pur-
sued those issues in its briefing before this court.
Accordingly, Polara has not properly raised any issue on
cross-appeal, and we need not address the cross-appeal.
POLARA ENGINEERING INC    v. CAMPBELL COMPANY                  3



     The ’476 patent relates to a two-wire control system
for push-button crosswalk stations for a traffic-light-
controlled intersection with visual, audible, and tactile
accessible signals. These signals “enable both sighted and
visually impaired pedestrians to receive information
concerning the status of the intersection to be crossed
once vehicular traffic has been halted.” ’476 patent col. 2
ll. 21–24. The patent discloses using a DC signal to
provide both power and digital data over two wires to
control the system. Id. col. 2 l. 44–col. 3 l. 11, col. 4 ll. 43–
63, Fig. 3. The patent explains the benefits of using “the
existing underground wire pairs to transmit power and
data signals in order to generate the accessible signal
functions for both sighted and visually impaired pedestri-
ans.” Id. col. 2 ll. 1–9.
    Claim 1 of the ’476 patent is representative and reads
as follows:
    A control system by which vibro-tactile messages
    are provided to alert pedestrians when to cross a
    traffic light controlled intersection, said control
    system comprising:
        at least one push button station located at
        the traffic light controlled intersection to
        be crossed by pedestrians, said push but-
        ton station including a push button head
        that is depressed by the pedestrians and
        message generating means adapted to
        cause said push button head to vibrate to
        provide a tactile indication to a visually
        impaired pedestrian when to cross the in-
        tersection; and
        a control unit that is responsive to the de-
        pression of the push button head of said
        push button station to transmit to the
        push button station both power and digital
        data signals over a single pair of wires by
4             POLARA ENGINEERING INC    v. CAMPBELL COMPANY



        which to power and control the operation
        of said message generating means.
Id. col. 9 l. 56–col. 10 l. 4 (emphasis added).
   Polara filed the application that led to the ’476 patent
on August 5, 2004. The critical date for purposes of pre-
AIA 35 U.S.C. § 102(b) (2006) 2 is thus August 5, 2003. In
September 2003, Polara began selling the Navigator-2, a
two-wire APS system that practices the asserted claims.
                              II
     Prior to the critical date, Polara tested prototypes that
satisfied the limitations of the asserted claims. Polara
first developed a prototype that it tested in its laboratory.
In January 2002, it tested the prototype in its parking lot.
It also sent a letter to the traffic engineer for the City of
Fullerton, California requesting permission to install a
prototype system at the intersection of Gilbert Street and
Commonwealth Avenue. The letter explained that the
intersection was “close to [Polara’s] plant” so they could
“monitor it daily during the test phase.” J.A. 3728. The
letter also stated that Polara “would take full responsibil-
ity for installing, maintaining and deinstalling [sic] the
equipment,” and that the City of Fullerton “would need to
provide a responsible representative to open the intersec-
tion cabinet for installation and deinstallation [sic] of the
system” and maybe a few other times during the test
period. Id.
    Following the city’s agreement, in March 2002, Polara
installed a prototype in Fullerton at the intersection of
Gilbert Street and Commonwealth Avenue (“First Instal-



    2  Because the ’476 patent issued before the enact-
ment of the Leahy–Smith America Invents Act (“AIA”),
Pub. L. No. 112–29, 125 Stat. 284 (2011), we apply the
pre-AIA version of 35 U.S.C. §§ 102, 103.
POLARA ENGINEERING INC   v. CAMPBELL COMPANY               5



lation”).   Because that prototype immediately failed,
Polara ran tests and uninstalled it. Polara determined
that the problem was with electrical noise impacting the
digital data signal. Based on this determination, Polara
modified the transmitting and receiving circuitry of the
prototype and then reinstalled it at the same intersection.
The modification process took a few months. Following
reinstallation, Polara monitored the operation of the First
Installation for a couple of months and then uninstalled
it.
     Polara subsequently installed a prototype in Fullerton
at the intersection of Nutwood Avenue and College Boule-
vard (“Second Installation”), a larger intersection with a
different configuration than at the location of the First
Installation. The Second Installation initially experi-
enced intermittent problems with the digital data signal
communication resulting in Polara modifying the proto-
type’s circuitry. The Second Installation was in use from
fall 2002 to fall 2003. Polara’s president testified that
they “continued to monitor it and consider it a test inter-
section . . . until the official release of the [Navigator-2]
device at the August 24[, 2003] trade show.” J.A. 3000–
01; see also J.A. 2517–18 (inventor testimony regarding
testing and monitoring of the Second Installation).
    Polara did not enter into a confidentiality agreement
with the City of Fullerton with respect to the First and
Second Installations. Polara witnesses testified that they
did not tell anyone from the city how the prototype
worked and that a person could not determine how the
device worked once it was installed merely by looking at
it. According to the terms of the January 2002 letter,
Polara employees installed, uninstalled, and performed
testing of the prototypes at the First and Second Installa-
tions.
   In January 2003, Polara had a prototype installed in
Burnaby, Canada. Polara entered into an agreement with
6            POLARA ENGINEERING INC   v. CAMPBELL COMPANY



the City of Burnaby to test the prototype and keep the
information concerning the prototype and its testing
confidential. J.A. 3745–46. The City of Burnaby ar-
ranged for Cobra Electric to install and monitor the test
system and Polara also had Cobra sign a confidentiality
agreement. J.A. 3748. Polara selected Burnaby as a test
location because of the different environmental condi-
tions, e.g., heavy rain and snowfall, than in Fullerton.
                            III
     In or around 2008, Campbell, a manufacturer of traf-
fic-industry products, began collaborating with Dr. Rich-
ard Wall of the University of Idaho to develop an APS.
That collaboration led to the development of Campbell’s
Advisor Advanced Accessible Pedestrian Station
(“AAPS”), a two-wire APS.
     In May 2008, Dr. Wall and Campbell personnel corre-
sponded regarding the system under development and the
’476 patent and discussed the possibility of developing a
three-wire APS. Dr. Wall identified what he termed
“significant differences” and “similarities” between the
’476 patent and proposed APS. J.A. 3362. The “similari-
ties” included “two wire communications over power line.”
Id. Dr. Wall subsequently sent an email to Phil Tate,
Campbell’s president, stating “I have my design team on
it – we may have a 3 wire solution.” J.A. 3829. Mr. Tate
testified that one reason he wanted to consider a three-
wire solution was that “[i]t would make it much cleaner”
in light of the ’476 patent. J.A. 2571.
    Dr. Wall also discussed the ’476 patent with a tech-
nology transfer attorney employed by the University of
Idaho, Michael Jones, and reported his conversation to
Mr. Tate. Mr. Jones identified “areas of potential conflict”
with the APS being developed and third-party patent
rights, including the ’476 patent. J.A. 2572–73, 2575. As
of May 2008, Mr. Jones had not given a two-wire APS “a
clean bill of health.” J.A. 2574.
POLARA ENGINEERING INC   v. CAMPBELL COMPANY              7



    Around the same time period, Mr. Tate also discussed
the ’476 patent with an attorney named Bob Shaver, and
received a written analysis of the patent from his law
firm. The document begins by stating that “[a]ll but one
claim in the [’476] patent [is] limit[ed] to the 2-wire
configuration as previously discussed. Claim 11 does not
have this limitation.” J.A. 3832. The remainder of the
document focuses on claim 11, and does not provide an
analysis of the validity of the asserted claims or any
infringement analysis. This was the only written com-
munication Campbell received from a law firm that opines
on the ’476 patent.
                            IV
    On January 2, 2013, Polara filed this patent in-
fringement suit against Campbell. The district court
subsequently granted Polara’s motion for partial sum-
mary judgment that Campbell’s AAPS infringes claims 1–
4 of the ’476 patent. See Polara Eng’g, Inc. v. Campbell
Co., No. SACV-13-00007, slip op. (C.D. Cal. June 10,
2014) (J.A. 1–15). The AAPS transmits both AC power
and data via Ethernet over Powerline (“EoP”) packets
using orthogonal frequency division modulation (“OFDM”)
to the pushbuttons over a single pair of wires. J.A. 5, 12.
The court held that the AAPS “satisfies the ‘digital data
signals’ limitation” because it “sends EoP data packets to
pushbuttons using OFDM technology to encode digital
data onto electrical waveforms.” J.A. 13. The court
subsequently denied Campbell’s motion for reconsidera-
tion of the grant of summary judgment of infringement.
See Polara Eng’g, Inc. v. Campbell Co., No. SACV-13-
00007, 2015 WL 12914379 (C.D. Cal. May 26, 2015).
    Although the district court expressly construed cer-
tain claim language in its summary judgment opinion, it
did not expressly construe “transmit[ting] . . . both power
and digital data signals . . . by which to power and control
the operation of said messages generating means”
8             POLARA ENGINEERING INC   v. CAMPBELL COMPANY



(“transmitting limitation”) or “digital data signals.” ’476
patent col. 9 l. 56–col. 10 l. 4. At trial, Polara argued that
the jury should be instructed that the transmitting limi-
tation means “transmitting a power signal and a separate
digital data signal encoded/embedded onto the power
signal, wherein the power signal powers the message
generating means and the digital data signal controls the
operation of the message generating means” based on
what the court had stated in its summary judgment order.
J.A. 334–41.
    Campbell objected to Polara’s proposal, and advocated
for a plain and ordinary meaning instruction to be given
for terms not expressly construed in the summary judg-
ment opinion, including “digital data signals.” J.A. 358–
59, 3167–68; see also J.A. 354–58. In the alternative,
Campbell argued that the jury should receive a claim
construction instruction using the “exact language” used
by the district court in its summary judgment opinion.
J.A. 358–59. The district court instructed the jury to give
the non-expressly construed words, including “digital data
signals,” “their ordinary and customary meaning.” J.A.
3214.
    At the conclusion of the trial, the jury returned a spe-
cial verdict finding, inter alia, that Campbell willfully
infringed the asserted claims and that the asserted claims
were not proven invalid under 35 U.S.C. §§ 102, 103. The
district court had previously denied the parties’ relevant
pre-verdict JMOL motions. 3
   Following post-trial briefing, the district court denied
Campbell’s renewed motions for JMOL that the infringe-



    3   The court granted Polara’s motion for JMOL that
the claims were not shown to be invalid under the on-sale
bar of pre-AIA § 102. Campbell has not appealed this
determination.
POLARA ENGINEERING INC   v. CAMPBELL COMPANY              9



ment was not willful and the claims were invalid pursu-
ant to 35 U.S.C. §§ 102, 103. The court upheld the jury’s
verdict that the invention was not in public use for more
than a year before the filing of the application that led to
the ’476 patent. The court held that substantial evidence
supported the jury’s finding that Polara’s installation of
prototypes in Fullerton was experimental use necessary
to ensure that the invention would work for its intended
purpose.
     The district court determined that Campbell had
failed to prove that the asserted claims would have been
obvious over the cited prior art. Campbell’s arguments
focused on two-wire prior art APSs sold starting in the
late 1990s, i.e., its Enlightened, a combination DC/AC-
based system, and the third-party Tassimco PIU 500, a
DC-based system, and U.S. Patent 4,851,836 (“Wil-
kinson”), which teaches a two-wire AC-based system. The
court held that substantial evidence supported the jury’s
implicit finding that Tassimco, Enlightened, and Wil-
kinson did not disclose the claimed digital-data-over-
power limitation and that objective indicia of commercial
success, long-felt need, and copying support a conclusion
of nonobviousness.
    The district court also upheld the jury’s willfulness
finding and, applying the factors listed in Read Corp. v.
Portec, Inc., 970 F.2d 816, 826–27 (Fed. Cir. 1992), en-
hanced damages by two-and-a-half times. The district
court determined that five of the nine Read factors fa-
vored an award of enhanced damages, two of the factors
weighed against enhancement, and two of the factors
were neutral.
                       DISCUSSION
    We review the denial of a motion for JMOL under the
law of the regional circuit. ClearValue, Inc. v. Pearl River
Polymers, Inc., 668 F.3d 1340, 1343 (Fed. Cir. 2012). In
the Ninth Circuit, the denial of a motion for JMOL is
10            POLARA ENGINEERING INC   v. CAMPBELL COMPANY



reviewed de novo. Pavao v. Pagay, 307 F.3d 915, 918 (9th
Cir. 2002). “A jury’s verdict must be upheld if it is sup-
ported by substantial evidence, which is evidence ade-
quate to support the jury’s conclusion, even if it is also
possible to draw a contrary conclusion.” Id. “While the
court must review the entire evidentiary record, it must
view all evidence in the light most favorable to the non-
moving party, draw all reasonable inferences in the favor
of the non-mover, and disregard all evidence favorable to
the moving party that the jury is not required to believe.”
Harper v. City of Los Angeles, 533 F.3d 1010, 1021 (9th
Cir. 2008).
    Campbell argues that the district court erred by not
granting JMOL of invalidity and that the infringement
was not willful. Campbell further contends that the
district court abused its discretion in enhancing the
damages award. Polara responds that the jury’s verdict
was supported by substantial evidence, and that the court
did not abuse its discretion. We address each of these
arguments in turn.
                         I. Validity
    Campbell argues that the asserted claims are invalid
both for prior public use and over the prior art. Patents
are presumed valid. 35 U.S.C. § 282. At trial, the party
challenging validity must prove that the claims are inva-
lid by clear and convincing evidence. Microsoft Corp. v.
i4i Ltd., 564 U.S. 91, 95 (2011).
                       A. Public Use
    Under pre-AIA 35 U.S.C. § 102(b): “A person shall be
entitled a patent unless . . . the invention was . . . in
public use . . . in this country, more than one year prior to
the date of the application for patent in the United
POLARA ENGINEERING INC   v. CAMPBELL COMPANY              11



States.” 4 “Although the determination of whether a
patent is invalid for public use is a question of law that
we review de novo, the disputed facts found to support
that determination are reviewed for substantial evi-
dence.” Lisle Corp. v. A.J. Mfg. Co., 398 F.3d 1306, 1313
(Fed. Cir. 2005). We treat the jury’s verdict of no invali-
dating public use “as a resolution of all genuinely disput-
ed underlying factual issues in favor of the verdict
winner.” Id. at 1312.
     The public use bar is triggered “where, before the crit-
ical date, the invention is in public use and ready for
patenting.” Invitrogen Corp. v. Biocrest Mfg., L.P., 424
F.3d 1374, 1379 (Fed. Cir. 2005). Proof of reduction to
practice before the critical date demonstrates that the
invention is ready for patenting. Pfaff v. Wells Elecs.,
Inc., 525 U.S. 55, 67 (1998). “Reduction to practice occurs
if ‘the claimant had possession of the subject matter of the
[claim] and . . . it was shown or known to work for its
intended purpose.’” Helsinn Healthcare S.A. v. Teva
Pharm. USA, Inc., 855 F.3d 1356, 1372 (Fed. Cir. 2017)
(first alteration in original) (quoting Streck, Inc. v. Re-
search & Diagnostic Sys., Inc., 659 F.3d 1186, 1193 (Fed.
Cir. 2011)), cert. granted, No. 17-1229, 2018 WL 1142984
(U.S. June 25, 2018).
    However, “an inventor who seeks to perfect his dis-
covery may conduct extensive testing without losing his
right to obtain a patent for his invention—even if such
testing occurs in the public eye.” Pfaff, 525 U.S. at 64.
Proof of experimental use serves “as a negation of the
statutory bars.” EZ Dock v. Schafer Sys., Inc., 276 F.3d
1347, 1352 (Fed. Cir. 2002). A use may be experimental if
its purpose is: “(1) [to] test claimed features of the inven-


    4   Because pre-AIA § 102(b) applies to this case, the
testing in Canada cannot constitute an invalidating prior
public use.
12            POLARA ENGINEERING INC   v. CAMPBELL COMPANY



tion or (2) to determine whether an invention will work
for its intended purpose—itself a requirement of patenta-
bility.” Clock Spring, L.P. v. Wrapmaster, Inc., 560 F.3d
1317, 1327 (Fed. Cir. 2009).
    We have identified a number of factors that may be
relevant to determining whether a use is experimental:
     (1) the necessity for public testing, (2) the amount
     of control over the experiment retained by the in-
     ventor, (3) the nature of the invention, (4) the
     length of the test period, (5) whether payment was
     made, (6) whether there was a secrecy obligation,
     (7) whether records of the experiment were kept,
     (8) who conducted the experiment, (9) the degree
     of commercial exploitation during testing, (10)
     whether the invention reasonably requires evalu-
     ation under actual conditions of use, (11) whether
     testing was systematically performed, (12) wheth-
     er the inventor continually monitored the inven-
     tion during testing, and (13) the nature of contacts
     made with potential customers.
Id. (internal quotation marks and citations omitted).
    Campbell argues that the district court erred in deny-
ing its motion for JMOL that the asserted claims are
invalid for prior public use before the critical date.
Campbell contends that substantial evidence does not
support the jury’s finding of experimental use with re-
spect to the testing done in Fullerton. Rather, Campbell
asserts, the evidence established that the inventors
reduced the invention to practice as early as January
2002 and no later than March 2002. Campbell further
argues that the evidence established that Polara’s public
uses were to test non-claimed features and were not
undertaken for the purposes of filing a patent application.
   Polara responds that the jury’s finding of experi-
mental use was supported by substantial evidence.
POLARA ENGINEERING INC   v. CAMPBELL COMPANY             13



Polara contends that it was testing claimed features, i.e.,
the “digital data signals” limitation. Polara argues that
testing to ensure that the invention would work for its
intended purpose and in its intended environment consti-
tutes experimental use.
    We agree with Polara that substantial evidence sup-
ports the jury’s finding of experimental use that negates
application of the public use bar. The jury heard testimo-
ny that Polara needed to test the claimed invention at
actual crosswalks of different sizes and configurations and
where the prototype would experience different weather
conditions to ensure that the invention would work for its
intended purpose. The jury also heard testimony under-
scoring the importance of such testing of the invention as
“a life safety device,” J.A. 2233, that the testing was
“imperative,” J.A. 2243, and that “public safety is [Po-
lara’s] primary focus. The last thing [Polara] would want
to do is rush a product out and get it out there and have it
not work and work incorrectly and put somebody out into
an unsafe condition,” id.; accord J.A. 2999–3000.
    We reject Campbell’s contention that this testimony is
insufficient to support the jury’s finding of experimental
use. The jury could have properly based its finding of
experimental use on the need for testing to ensure the
durability and safety of the claimed APS. In City of
Elizabeth v. American Nicholson Pavement Co., the Su-
preme Court held that testing an inventive pavement for
“usefulness and durability” for six years on a public
roadway constituted experimental use. 97 U.S. 126, 133–
34 (1877). We have similarly recognized as sufficient to
negate the statutory bar experimental use testing per-
formed “to perfect features inherent to the claimed inven-
tion,” such as “durability.” Electromotive Div. of Gen.
Motors Corp. v. Transp. Sys. Div. of Gen. Elec. Co., 417
F.3d 1203, 1211–12 (Fed. Cir. 2005) (collecting cases);
accord Manville Sales Corp. v. Paramount Sys., Inc., 917
F.2d 544, 551 (Fed. Cir. 1990) (“When durability in an
14            POLARA ENGINEERING INC   v. CAMPBELL COMPANY



outdoor environment is inherent to the purpose of an
invention, then further testing to determine the inven-
tion’s ability to serve that purpose will not subject the
invention to a section 102(b) bar.”). Moreover, the safety
and durability testing Polara conducted at the First and
Second Installations related to claimed features, most
particularly the claimed transmission of digital data
signals over a single pair of wires.
     In City of Elizabeth, the Supreme Court explained:
     [The inventor] wished to experiment on his pave-
     ment. He believed it to be a good thing, but he
     was not sure; and the only mode in which he could
     test it was to place a specimen of it in a public
     roadway. He did this at his own expense, and
     with the consent of the owners of the road. Dura-
     bility was one of the qualities to be attained. He
     wanted to know whether his pavement would
     stand, and whether it would resist decay. Its
     character for durability could not be ascertained
     without its being subjected to use for a considera-
     ble time. He subjected it to such use, in good
     faith, for the simple purpose of ascertaining
     whether it was what he claimed it to be. . . . The
     public had the incidental use of the pavement, it
     is true; but was the invention in public use, within
     the meaning of the statute? We think not. The
     proprietors of the road alone used the invention,
     and used it at [the inventor’s] request, by way of
     experiment. The only way in which they could use
     it was by allowing the public to pass over the
     pavement.
97 U.S. at 136.
    The factual situation here bears a striking similarity
to the situation in City of Elizabeth. Given that the
invention relates to public safety in crossing the street,
the inventors could reasonably believe that they needed to
POLARA ENGINEERING INC   v. CAMPBELL COMPANY             15



ensure the invention’s durability and safety before being
certain that it would work for its intended purpose. The
trial testimony showed that durability and safety of the
system could not be ascertained without it being subjected
to use for a considerable period of time under different
actual use conditions, e.g., different crosswalk sizes and
configurations and different environments. Experiment-
ing under actual use conditions necessitated that the
testing occur at public intersections. Polara conducted
this testing at its own expense and the jury heard testi-
mony that supported finding that Polara was not com-
mercially exploiting the invention during the Fullerton
testing.
    We reject Campbell’s argument that the Clock Spring
factors compel a finding of a lack of experimental use in
this case. As discussed above, the jury heard testimony
from which it could have determined that many of the
factors, including the necessity of public testing, the
nature of the invention, the lack of payment for the inven-
tion, the experiments being conducted by Polara, and the
invention reasonably requiring evaluation under actual
use conditions, favored finding experimental use. See
Post-trial Motions Opinion, 237 F. Supp. 3d at 970. That
Campbell points to evidence that could have supported a
contrary finding does not mean that the jury reached an
impermissible verdict. See Pavao, 307 F.3d at 918 (“A
jury’s verdict must be upheld if it is supported by sub-
stantial evidence, which is evidence adequate to support
the jury’s conclusion, even if it is also possible to draw a
contrary conclusion.”).
    For example, although it is undisputed that Polara
did not enter into a confidentiality agreement with Fuller-
ton, Polara introduced evidence that it maintained the
secrecy of the invention in other ways. The jury heard
testimony that Polara installed, uninstalled, and tested
the prototypes itself and did not explain to the Fullerton
employees how the invention operated. The functionality
16           POLARA ENGINEERING INC   v. CAMPBELL COMPANY



of the system was also not apparent to pedestrians using
the system.
     Similarly, while Polara tested the prototypes at public
intersections for numerous months without making
additional changes, Polara introduced testimony support-
ing the necessity of this period of testing to ensure safety
and durability. The jury also heard testimony that the
prototypes initially failed at the First and Second Instal-
lations, and that Polara had to make changes to the
prototypes for the system to work properly. Mr. Beckwith
testified that these changes were related to the claimed
transmission of digital data signals. Additionally, alt-
hough a lack of contemporaneous records of the experi-
ments is a factor that may support finding the use non-
experimental, a lack of such records does not compel such
a finding.
    Finally, while Campbell elicited some testimony that
could support finding that the Fullerton testing was to
test commercial features, the jury also heard testimony
that supported finding that Polara was not commercially
exploiting its invention during the test periods and that
the testing was necessary for patentability to ensure that
the invention would work for its intended purpose. Alt-
hough the public use issue is close, given this mixed
factual record, we cannot say that the jury’s finding of
experimental use lacked substantial evidentiary support.
To the extent Campbell invites us to reweigh the evi-
dence, we decline the invitation. See Harper, 533 F.3d at
1021 (explaining on JMOL “the court must not weigh the
evidence, but should simply ask whether the plaintiff has
presented sufficient evidence to support the jury’s conclu-
sion”).
                       B. Prior Art
    Anticipation is a question of fact reviewed for sub-
stantial evidence following a jury verdict. TI Grp. Auto.
Sys. (N. Am.), Inc. v. VDO N. Am., L.L.C., 375 F.3d 1126,
POLARA ENGINEERING INC   v. CAMPBELL COMPANY             17



1133 (Fed. Cir. 2004). Obviousness is a question of law
with underlying factual issues. Graham v. John Deere Co.
of Kansas City, 383 U.S. 1, 17 (1966). Following a jury
verdict on obviousness, “we first presume that the jury
resolved the underlying factual disputes in favor of the
verdict and leave those presumed findings undisturbed if
they are supported by substantial evidence.” Kinetic
Concepts, Inc. v. Smith & Nephew, Inc., 688 F.3d 1342,
1356–57 (Fed. Cir. 2012) (internal quotation marks and
alterations omitted). We then “examine the ultimate
legal conclusion of obviousness de novo to see whether it
is correct in light of the presumed jury fact findings.” Id.
at 1357 (internal quotation marks and alterations omit-
ted).
    Campbell argues that the district court erred by not
granting JMOL of anticipation based on Wilkinson, or
obviousness based on Wilkinson, Tassimco, and/or En-
lightened. According to Campbell, the district court’s
failure to instruct the jury regarding the court’s implicit
prior construction of “digital data signals” to “mean both
DC and AC signals” resulted in the jury applying a differ-
ent claim construction to reject the invalidity challenges
from the one the court applied to find infringement at
summary judgment. Appellant Br. 41–42. Campbell
further argues that the court erred by not resolving the
parties’ dispute regarding the construction of “digital data
signals” as required by O2 Micro International Ltd. v.
Beyond Innovation Technology Co., 521 F.3d 1351 (Fed.
Cir. 2008).
    Polara responds that the district court did not err in
its claim construction instructions to the jury and that
substantial evidence supports the jury’s findings. Polara
contends that Campbell is estopped from arguing that the
district court erred in its claim construction instruction
because the court adopted Campbell’s proposed construc-
tion of “digital data signals.” According to Polara, Wil-
kinson, Tassimco, and Enlightened are simple analog
18            POLARA ENGINEERING INC   v. CAMPBELL COMPANY



devices that do not disclose the “digital data signals”
limitation. Polara also contends that Campbell waived its
argument that Wilkinson anticipates the asserted claims
by not raising it in its Rule 50(b) motion.
    We agree with Polara that the district court did not
commit reversible error in instructing the jury on claim
construction. While Campbell is correct “that claims are
construed the same way for both invalidity and infringe-
ment,” Amgen Inc. v. Hoechst Marion Roussel, Inc., 314
F.3d 1313, 1330 (Fed. Cir. 2003), it has failed to show that
the court’s instructions permitted the jury to apply a
different claim construction at trial from the one that the
court applied on summary judgment.
     As an initial matter, we find disingenuous Campbell’s
assertion that it “did not assert [to the district court] that
. . . ‘digital data signals’ should be given [its] ‘plain and
ordinary meaning.’” Reply Br. 13. Campbell urged the
district court to adopt an instruction using the “exact
language” used by the district court in its summary
judgment opinion or “the [p]lain and [o]rdinary
[m]eaning” for all terms not expressly construed in the
summary judgment opinion, including “digital data sig-
nals.” J.A. 358–59. Campbell has pointed us to no por-
tion of the record where it withdrew its suggestion that
the district court adopt a plain and ordinary meaning
instruction, or told the court that an instruction with the
“exact language” of the summary judgment opinion was
its preferred instruction. Accordingly, “we look with
extreme disfavor” on Campbell’s assertion that the dis-
trict court erred by adopting a claim construction position
it advocated at trial. Key Pharm. v. Hercon Labs. Corp.,
161 F.3d 709, 715 (Fed. Cir. 1998). Indeed, we have
recognized that “a party will be judicially estopped from
asserting a position on appeal that is inconsistent with a
position it advocated at trial and persuaded the trial court
POLARA ENGINEERING INC   v. CAMPBELL COMPANY             19



to adopt.” Interactive Gift Exp., Inc. v. Compuserve Inc.,
256 F.3d 1323, 1346 (Fed. Cir. 2001). 5
     Even if Campbell were not judicially estopped, Camp-
bell’s argument appears to be based on the unsupported
assertion that the jury could only have found that Wil-
kinson, Tassimco, and Enlightened did not teach the
“digital data signals” limitation by applying a claim
construction excluding AC signals from “digital data
signals.” Campbell has pointed to no evidence that Polara
made such an argument at trial. The viability of Camp-
bell’s contention is further foreclosed by Campbell’s
admission that “Tassimco is a DC-based system,” Appel-
lant Br. 20, and failure to cite any evidence that Wil-
kinson, Tassimco, and/or Enlightened send the alleged
“digital data signals” in the same way as the district court
stated the AAPS does, i.e., via “EoP data packets to
pushbuttons using OFDM technology to encode digital
data onto electrical waveforms,” J.A. 13.
   We also agree with Polara that the jury’s findings that
Wilkinson, Tassimco, and Enlightened do not teach or
suggest the “digital data signals” limitation are supported




   5     Given this record, the district court also did not
commit reversible error by not resolving a claim construc-
tion dispute between the parties. The court resolved the
only dispute presented to it by adopting Campbell’s
proposal to instruct the jury on plain and ordinary mean-
ing. See O2 Micro, 521 F.3d at 1362 (recognizing that
“district courts are not (and should not be) required to
construe every limitation present in a patent’s asserted
claims” and explaining “[w]hen the parties present a
fundamental dispute regarding the scope of a claim term,
it is the court’s duty to resolve it”).
20            POLARA ENGINEERING INC   v. CAMPBELL COMPANY



by substantial evidence. 6 We note that Campbell advo-
cates for an incorrect standard on appeal. The question is
not whether Campbell’s “losing position was also support-
ed by substantial evidence,” but rather “whether substan-
tial evidence supports [the jury’s] implied fact finding.”
Apple Inc. v. Samsung Elecs. Co., 839 F.3d 1034, 1052
(Fed. Cir. 2016) (en banc), cert. denied, 138 S. Ct. 420
(2017). Polara presented substantial evidence from which
the jury could have found that the prior art did not teach
or suggest the “digital data signals” limitation. The fact
that Campbell presented competing evidence to support
its invalidity contentions does not compel a different
outcome. See id. Additionally, we reject Campbell’s
arguments predicated on the “combining of well-known
prior art ‘digital data signals’” with Wilkinson, Tassimco,
and Enlightened, Appellant Br. 51, for a failure of proof
on motivation to combine. See Post-trial Motions Opinion,
237 F. Supp. 3d at 973; see also Apple, 839 F.3d at 1051–
52.
                  II. Enhanced Damages
    Under 35 U.S.C. § 284 “the court may increase the
damages up to three times the amount found or assessed.”
The Supreme Court has described § 284 “as providing
that punitive or increased damages could be recovered in
a case of willful or bad-faith infringement.” Halo Elecs.,
Inc. v. Pulse Elecs., Inc., 136 S. Ct. 1923, 1930 (2016)
(internal quotation marks omitted). The Court has thus
instructed that enhanced damages “are not to be meted
out in a typical infringement case, but are instead de-
signed as a ‘punitive’ or ‘vindictive’ sanction for egregious
infringement behavior,” and explained that “[t]he sort of
conduct warranting enhanced damages has been various-


     6 Given our resolution of this issue, we need not,
and do not, address whether Campbell waived its argu-
ment for JMOL based on anticipation by Wilkinson.
POLARA ENGINEERING INC   v. CAMPBELL COMPANY               21



ly described in our cases as willful, wanton, malicious,
bad-faith, deliberate, consciously wrongful, flagrant, or—
indeed—characteristic of a pirate.” Id. at 1932. We
review a district court’s ultimate decision whether to
enhance damages for abuse of discretion. Id. at 1934.
     Willful infringement is a question of fact reviewed for
substantial evidence following a jury trial. WBIP, LLC v.
Kohler Co., 829 F.3d 1317, 1341–42 (Fed. Cir. 2016). A
finding of willful infringement does not require the dis-
trict court to award enhanced damages. Halo, 136 S. Ct.
at 1933. The district court thus retains “the discretion to
decide whether the case is sufficiently egregious to war-
rant enhancing damages and to decide the amount of
enhancement that is warranted (up to the statutory limit
of treble damages).” WBIP, 829 F.3d at 1342.
    Campbell argues that, applying the Halo standard,
the jury’s willfulness verdict lacked substantial evidence
and the court abused its discretion in awarding enhanced
damages. Campbell also contends that it “was not al-
lowed to present its pre-litigation non-infringement
defenses to the jury to refute willfulness,” and that the
district court “erred in not requiring the jury to assess
Campbell’s alleged willfulness throughout the period of
alleged infringement.” Appellant Br. 53–54. Campbell
further argues that the district court erred by failing to
consider that Polara never sought a preliminary injunc-
tion and thus “should not be allowed to accrue enhanced
damages based solely on the infringer’s post-filing con-
duct.” Appellant Br. 55 (quoting In re Seagate Tech., LLC,
497 F.3d 1360, 1374 (Fed. Cir. 2007)).
    Polara responds that substantial evidence supports
the jury’s willfulness verdict, and the district court did not
abuse its discretion in enhancing damages. Polara con-
tends that Campbell was not prohibited from presenting
its pre-litigation noninfringement defenses to the jury,
and did in fact argue noninfringement to the jury. Polara
22           POLARA ENGINEERING INC   v. CAMPBELL COMPANY



argues that Campbell waived its other alleged errors by
failing to timely raise them to the district court.
    We agree with Polara that substantial evidence sup-
ports the jury’s finding of willful infringement. Based on
the evidence adduced at trial, the jury reasonably could
have found that Campbell intentionally copied the ’476
patent despite a significant known risk that its two-wire
AAPS would infringe the ’476 patent. It is undisputed
that Campbell was aware of the ’476 patent prior to
developing its AAPS. Campbell’s president testified that
Campbell developed its AAPS to compete with Polara’s
Navigator-2, and that Campbell did not have a product
that could compete with the Navigator-2 when Polara
launched it in 2003. The jury also heard evidence that
Campbell adopted a two-wire design for its AAPS despite
being advised by University of Idaho counsel and its lead
developer of “areas of potential conflict,” J.A. 2572–73,
2575, and “similarities,” J.A. 3362, with the ’476 patent.
    Campbell asserts that its reliance on competent opin-
ion of counsel demonstrates its good faith belief that the
’476 patent was invalid or not infringed. Campbell has
not pointed to any documentary or third-party evidence
showing it received an opinion of counsel that the assert-
ed claims of the ’476 patent are invalid and/or would not
be infringed by its AAPS. To the extent Campbell relies
on the testimony of its president that Campbell allegedly
eventually received “a clean bill of health” from the Uni-
versity of Idaho and “got the go” from his own “IP attor-
neys,” J.A. 2574, the jury was entitled not to credit this
testimony, see Harper, 533 F.3d at 1021 (“While the court
must review the entire evidentiary record, it must . . .
disregard all evidence favorable to the moving party that
the jury is not required to believe.”).
    The only written opinion of counsel Campbell received
that it alleges shows its good faith only substantively
discusses claim 11, which is not at issue in this case. The
POLARA ENGINEERING INC   v. CAMPBELL COMPANY              23



document begins by stating “[a]ll but one claim in the
[’476] patent [is] limit[ed] to the 2-wire configuration
previously discussed. Claim 11 does not have this limita-
tion.” J.A. 3832. We agree with the district court that a
“fair reading” of this document “is that [the author] as-
sumed that Campbell did not intend to adopt a two-wire
device.” Post-trial Motions Opinion, 237 F. Supp. 3d at
981. We thus must assume that the jury adopted this
view of the document. See Harper, 533 F.3d at 1021 (on
JMOL the court “must view all evidence in the light most
favorable to the nonmoving party[ and] draw all reasona-
ble inferences in the favor of the non-mover”). According-
ly, it offers little, if any, support for the contention that
Campbell acted in good faith or had a reasonable basis to
believe that the asserted claims are invalid or would not
be infringed.
     Moreover, Campbell’s contention that it “was not al-
lowed to present its pre-litigation non-infringement
defenses to the jury to refute willfulness,” Appellant Br.
53–54, is belied by the record. Campbell provides no
record citation to support this contention, and portions of
the record cited by Polara and the district court refute it.
We thus agree with the district court that “nothing pre-
vented Campbell from vigorously and steadfastly main-
taining that it reasonably believed that it had a defense to
Polara’s charges of infringement. As Polara points out,
Campbell did just that, arguing that Tate believed that
Campbell’s products did not infringe and that the ’476
Patent was invalid.” Post-trial Motions Opinion, 237 F.
Supp. 3d at 979 (citing J.A. 3323–24).
     Additionally, Campbell waived its argument that the
district court erred by presenting the jury with a verdict
form that required a simple “yes” or “no” answer on the
question of willfulness, rather than requiring the jury to
specify the time period during which Campbell’s conduct
was willful. While Campbell is correct that “culpability is
generally measured against the knowledge of the actor at
24           POLARA ENGINEERING INC   v. CAMPBELL COMPANY



the time of the challenged conduct,” Halo, 136 S. Ct. at
1933, Campbell did not object to the district court’s pro-
posed verdict form on this basis, see Post-trial Motions
Opinion, 237 F. Supp. 3d at 979. By not timely informing
the district court that failing to adopt Campbell’s pro-
posed verdict form would be “an error of law or abuse of
discretion,” Campbell waived its objection to the verdict
form. United States v. Parson Corp., 1 F.3d 944, 945 (9th
Cir. 1993).
    Similarly, Campbell waived its Seagate-based argu-
ment that the district court should have considered that
Polara did not seek a preliminary injunction in its analy-
sis by failing to raise it to the district court. As the Su-
preme Court has observed, as a “general rule . . . a federal
appellate court does not consider an issue not passed
upon below.” Singleton v. Wulff, 428 U.S. 106, 120 (1976).
Although we have discretion to decide when to deviate
from this general rule, see id. at 121, Campbell has not
articulated a basis for us to reach this issue for the first
time on appeal and we discern none, see HTC Corp. v.
IPCom GmbH & Co., KG, 667 F.3d 1270, 1282–83 (Fed.
Cir. 2012); In re Cybernetic Serv., Inc., 252 F.3d 1039,
1045 n.3 (9th Cir. 2001). Moreover, the relied-upon
language does not even apply to this situation because the
jury’s finding of willful infringement was not “based solely
on the infringer’s post-filing conduct.” Seagate, 497 F.3d
at 1374.
    We next turn to the district court’s decision to en-
hance the damages award by two-and-a-half times.
Although “the district court is not required to discuss the
Read factors,” Presidio Components, Inc. v. Am. Tech.
Ceramics Corp., 875 F.3d 1369, 1382 (Fed. Cir. 2017), it
“is obligated to explain the basis for the [enhanced dam-
ages] award, particularly where the maximum amount is
imposed,” Read, 970 F.2d at 828. In exercising its discre-
tion, the district court must “take into account the partic-
ular circumstances of each case,” Halo, 136 S. Ct. at 1933,
POLARA ENGINEERING INC   v. CAMPBELL COMPANY             25



and “consider all relevant factors in determining whether
to award enhanced damages,” WesternGeco L.L.C. v. ION
Geophysical Corp., 837 F.3d 1358, 1363 (Fed. Cir. 2016),
rev’d on other grounds sub nom. WesternGeco LLC v. ION
Geophysical Corp., No. 16-1011, 2018 WL 3073503 (U.S.
June 22, 2018). After Halo and under Read, the “close-
ness of the case” remains a relevant consideration for
determining the appropriateness of enhancement. Here,
the district court awarded almost the maximum amount
of enhanced damages, but did not adequately explain its
basis for doing so, and failed to even mention Campbell’s
public use defense, which presented a close question in
this case.
     The district court referred to Campbell’s invalidity
theories generally in the closeness of the case Read factor.
In determining that this factor was “neutral,” the district
court merely observed that “obviousness was a close call”
and that the “other invalidity theories were weaker.”
Post-trial Motions Opinion, 237 F. Supp. 3d at 993. This
explanation is insufficient for us to determine why the
court viewed this factor as “neutral.” The court’s use of
the relative term “weaker” provides little insight because
it did not explain its reasons for viewing the other defens-
es, especially public use, as comparatively “weaker.” We
view the public use defense, which the court did not
explicitly address, as a closer call than obviousness.
Thus, to the extent the district court determined that the
public use defense was weak in this case, the court clearly
erred.
    Accordingly, we vacate the award of enhanced damag-
es and remand. See, e.g., Whitserve, LLC v. Comput.
Packages, Inc., 694 F.3d 10, 37 (Fed. Cir. 2012) (remand-
ing “for a determination of whether enhanced damages
are warranted and an explanation of the grounds for that
determination”); S.C. Johnson & Son, Inc. v. Carter-
Wallace, Inc., 781 F.2d 198, 202 (Fed. Cir. 1986) (“va-
cat[ing] the decision refusing [enhanced] damages under
26             POLARA ENGINEERING INC   v. CAMPBELL COMPANY



35 U.S.C. § 284, and remand[ing] for clarification by the
district court”). On remand, we instruct the district court
to provide a more complete explanation, including a
discussion of the public use defense, in exercising its
discretion. We express no view on whether damages
should be enhanced or, if so, by what amount.
    We have considered the parties’ remaining arguments
but find them to be unpersuasive.
                         CONCLUSION
    For the foregoing reasons, we affirm the district
court’s denial of judgment as a matter of law of invalidity
and no willful infringement, vacate the court’s enhanced
damages award, and remand for proceedings consistent
with this opinion.
     AFFIRMED IN PART, VACATED IN PART, AND
                   REMANDED
                           COSTS
      Costs to Polara.
