  United States Court of Appeals
      for the Federal Circuit
                 ______________________

                 ABT SYSTEMS, LLC,
                  Plaintiff-Appellant

THE UNIVERSITY OF CENTRAL FLORIDA BOARD
OF TRUSTEES, on behalf of the University of Cen-
                tral Florida,
                  Plaintiff

                            v.

              EMERSON ELECTRIC CO.,
               Defendant-Cross-Appellant
                ______________________

                  2014-1618, 2014-1700
                 ______________________

   Appeals from the United States District Court for the
Eastern District of Missouri in No. 4:11-cv-00374-AGF,
Judge Audrey G. Fleissig.
                ______________________

                Decided: August 19, 2015
                ______________________

    MICHAEL P. MAZZA, Michael P. Mazza, LLC, Glen
Ellyn, IL, argued for plaintiff-appellant. Also represented
by DANA D. ALVARADO.

    LINDA E.B. HANSEN, Foley & Lardner LLP, Milwau-
kee, WI, argued for defendant-cross-appellant.   Also
represented by JEFFREY COSTAKOS, KADIE M. JELENCHICK.
2                 ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.



                 ______________________

    Before PROST, Chief Judge, CLEVENGER, and SCHALL,
                    Circuit Judges.
SCHALL, Circuit Judge.
    This is a patent case. The University of Central Flor-
ida (“University”) is the assignee of U.S. Patent No.
5,547,017 (“the ’017 patent”), titled “Air Distribution Fan
Recycling Control.” The patent is licensed to ABT Sys-
tems, LLC (“ABT”). ABT and the University sued Emer-
son Electric Co. (“Emerson”) and three other defendants
in the United States District Court for the Northern
District of Illinois for infringement of claims 1–5 of the
’017 patent. Eventually, the case was transferred to the
United States District Court for the Eastern District of
Missouri and proceeded to trial before a jury against
Emerson alone after its three co-defendants settled.
Following trial, the jury found the asserted claims not
invalid by reason of obviousness and infringed by Emer-
son’s “Big Blue” thermostats. Based on a royalty rate of
$2.25 per unit, the jury awarded damages in the amount
of $311,379 on sales of 138,891 thermostats. ABT Sys.,
LLC v. Emerson Elec. Co., No. 4:11-cv-00374-AGF, 2013
WL 5567713, at *2 (E.D. Mo. Oct. 9, 2013).
     ABT appeals three rulings of the district court relat-
ing to damages. It contends these rulings were erroneous
and impacted its damages award. For its part, Emerson
cross-appeals the district court’s denial of its motion for
judgment as a matter of law (“JMOL”) that claims 1–5 of
the ’017 patent are invalid by reason of obviousness. See
id. at *3.
     For the reasons set forth below, we hold that the dis-
trict court erred in denying Emerson’s motion for JMOL of
invalidity. We therefore reverse the judgment of non-
invalidity, vacate the judgment of infringement, and
remand the case to the district court for dismissal of the
ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.                 3



complaint. In view of this disposition, it is not necessary
for us to address ABT’s appeal, which is rendered moot.
                         BACKGROUND
                              I.
    Armin Rudd is the sole inventor named on the ’017
patent. He assigned the patent to the University, his
employer at the time of the invention. The University
then licensed the patent to ABT. The technology involved
in the ’017 patent relates to heating, ventilation, and air
conditioning (“HVAC”) systems.
     The ’017 patent explains that prior art thermostats
for forced-air HVAC systems typically have two modes of
operation for the system fan. The first is for operating the
fan only when there is a call for heating or cooling from
the thermostat. This is necessary in order to distribute
air from the heating or cooling elements to the space to be
conditioned. Often, this is referred to as a thermostat’s
“auto” mode. The patent also explains that some prior art
thermostats include settings for continuous system fan
operation (i.e., “constant fan mode”), causing the fan to
run irrespective of a call for heating or cooling.
    The ’017 patent claims an apparatus for running an
HVAC system fan intermittently during periods when
there is no call for heating or cooling. In particular, the
’017 patent claims a forced central air system with a
“recycle control” for periodic fan operation when the
system is not heating or cooling. The periodic fan opera-
tion begins “a preselected time period” after the fan stops
at the end of a heating or cooling cycle, or after the termi-
nation of “constant fan mode” operation. Claim 1 is the
only independent claim at issue. It reads as follows:
    1. A fan recycling control apparatus for a central
    air conditioning (CAC) system comprising:
    a circulating fan;
4                 ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.



    a central air conditioning system with ducts to
    distribute cooled and heated conditioned air
    throughout a building;
    a thermostat for activating and deactivating both
    the central air conditioning system and the circu-
    lating fan;
    said activating causing a continuous fan opera-
    tion, said deactivating causing no fan operation,
    said thermostat further having a selectable con-
    stant fan mode, and
    a recycle control for periodically activating and
    deactivating only the circulating fan after a prese-
    lected time period, since the central air condition-
    ing system has been deactivated, or the circulating
    fan has been deactivated from the selectable con-
    stant fan mode.
’017 patent claim 1 (emphases added). Dependent claims
2–5 set forth limitations directed to specific types of
HVAC system heating and cooling modes. They also set
forth limitations relating to various types of heat sources
for the system.
    The specification of the ’017 patent touts the benefits
of running the fan periodically after a preselected time
from heating or cooling deactivation based on fan “recycle
control.” Those benefits include reduced air stagnation,
dilution of point sources of indoor air pollution, and
improved air cleaning. At the same time, periodic “recycle
control” is said to reduce energy consumption in compari-
son to the “constant fan mode” operation of prior art
thermostats.
                            II.
    Emerson manufactures various products, including
thermostats for use in HVAC systems. One of Emerson’s
products is the Big Blue thermostat, so named because of
ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.                 5



its blue user interface screen. In 2009, ABT and the
University sued Emerson for patent infringement, alleg-
ing that the so-called Comfort Circulating Fan Feature
(“CFF”) of the Big Blue thermostat infringed claims 1–5 of
the ’017 patent. As noted, following trial, the jury found
the asserted claims not invalid as obvious and infringed
and awarded ABT damages.

    At trial, in support of its invalidity defense, Emerson
relied primarily on four prior art references in the field of
HVAC systems and thermostats. Specifically, it argued
that the asserted claims of the ’017 patent would have
been obvious in view of U.S. Patent No. 2,013,136, to
Frank Cornelius (“Cornelius”); U.S. Patent No. 4,838,482,
to John Vogelzang (“Vogelzang”); U.S. Patent No.
2,953,908, to Dan Petrone et al. (“Petrone”); and/or U.S.
Patent No. 5,020,332, to Eiji Nakatsuno et al. (“Nakatsu-
no”). After the jury found the ’017 patent not invalid and
infringed, Emerson filed a motion for JMOL to set aside
the verdict.

    The district court denied Emerson’s motion. ABT
Sys., 2013 WL 5567713, at *1, *3. The court reasoned
that “[t]he jury could have reasonably found, based upon
the evidence, that the prior art relied upon by Defendant
did not disclose ‘periodic’ fan operation that was depend-
ent upon the deactivation of the heating or cooling func-
tion of the system, and further that was adaptable to
modern air conditioning systems.” Id. at *3. The court
stated: “The jury could have also found from the evidence
that there was a long-felt need for a periodic fan recycle
control as disclosed in the Rudd Patent.” Id. The court
continued that it could not “say as a matter of law that
the claimed invention is not more than the predictable
use of prior art elements according to their established
functions.”    Id. (internal quotation marks omitted).
Emerson timely cross-appealed the district court’s denial
6                  ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.



of its motion. We have jurisdiction pursuant to 28 U.S.C.
§ 1295(a)(1).
                        DISCUSSION
                             I.
    The standard for reviewing the grant or denial of
JMOL is not unique to patent law; the law of the regional
circuit therefore applies. Finisar Corp. v. DirecTV Grp.,
Inc., 523 F.3d 1323, 1328 (Fed. Cir. 2008). The Eighth
Circuit has instructed that decisions on motions for JMOL
are to be reviewed de novo, using the same standard that
the trial court applied. Penford Corp. v. Nat’l Union Fire
Ins. Co., 662 F.3d 497, 503 (8th Cir. 2011). JMOL against
a party on an issue is appropriate if “the court finds that a
reasonable jury would not have a legally sufficient eviden-
tiary basis to find for the party on that issue.” Fed. R.
Civ. P. 50(a). In deciding a JMOL motion, “all reasonable
inferences [are to be drawn] in favor of the nonmoving
party without making credibility assessments or weighing
the evidence.” Penford, 662 F.3d at 503 (quoting Phillips
v. Collings, 256 F.3d 843, 847 (8th Cir. 2001)).
     The standard for determining the validity of patent
claims is governed by our precedent. We have held that
invalidity must be established by clear and convincing
evidence. Transocean Offshore Deepwater Drilling, Inc. v.
Maersk Drilling USA, Inc., 699 F.3d 1340, 1347 (Fed. Cir.
2012); see also Commil USA, LLC v. Cisco Sys., Inc., 135
S. Ct. 1920, 1929 (2015) (noting that Congress is pre-
sumed to have chosen a “clear and convincing standard”
to overcome the presumption of validity of an issued
patent). A patent claim is invalid for obviousness if the
“differences between the subject matter sought to be
patented and the prior art are such that the subject
matter as a whole would have been obvious at the time
the invention was made to a person having ordinary skill
in the art to which said subject matter pertains.” 35
U.S.C. § 103(a) (2006). Obviousness under 35 U.S.C.
ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.                7



§ 103 is a mixed question of fact and law. Transocean,
699 F.3d at 1347. On appeal from a jury verdict on the
issue of obviousness, “we review all of the jury’s explicit
and implicit factual findings for substantial evidence. We
then examine the legal conclusion [on the issue] de novo
to determine whether it is correct in light of the factual
findings that we find adequately supported.” Kinetic
Concepts, Inc. v. Smith & Nephew, Inc., 688 F.3d 1342,
1360 (Fed. Cir. 2012).
                              II.
                              A.
    Emerson asks us to vacate the district court’s denial
of JMOL and to hold claims 1–5 of the ’017 patent obvious
in view of the Cornelius, Vogelzang, Petrone, and/or
Nakatsuno prior art references.
    Cornelius describes a furnace system with a circula-
tion fan that cycles on and off when there is no call for
heat from the thermostat. It teaches the ability “to in-
termittently start and stop” the fan when there is no call
for heat in order to “circulate air within the house.”
Cornelius col. 9 ll. 23–42. Cornelius discloses a “timing
device” for “operating the [circulation fan] motor at prede-
termined intervals,” so as to keep the room condition
maintained “from the standpoint of temperature, air
motion and cleanliness.” Id. Cornelius does not expressly
teach the timer being tied to the deactivation of the
heating elements, as required by claim 1 of the ’017
patent.
     Vogelzang discloses an HVAC system that provides
for movement of air and prevents stagnation through a
“cycle position” option on a thermostat. Vogelzang col. 2
ll. 36–46 (“A conventional fan cycler 35 is connected to
energize the fan relay 33 periodically such as several
times an hour to maintain periodic air flow through the
air cleaner 30 and to move the air about in the space 10.”).
8                  ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.



Vogelzang explains that the “invention is concerned with
a means for cycling the operation of the fan during peri-
ods when there is no operation of the heating apparatus
or cooling apparatus.” Id. col. 1 ll. 31–40. Like Cornelius,
Vogelzang discloses periodic fan operation when there is
no call for heating or cooling. Also like Cornelius, Vogel-
zang does not explicitly teach running the fan periodically
as a direct function of when the heating or cooling ele-
ments are deactivated. It instead relies on a timer that is
energized when a user places the thermostat in the “cycle
position.” Id. col. 2 ll. 46–48.
    The Petrone patent describes a control for a fan in a
forced-air cooling system. The fan of Petrone stops when
the call for cooling ends, at which point there is a delay
before the fan begins to operate independent of a call for
cooling. Petrone col. 6 ll. 64–71, col. 7 ll. 7–15 (“fan motor
will be stopped and at a predetermined time delay there-
after . . . the time delay switch will cause reenergization
of the fan motor”). The delay in Petrone is described as
permitting sufficient time for water to drain from the
cooling coils so as not to allow moisture to be blown into
the area to be cooled. Id. col. 4 ll. 18–22. Petrone does
not disclose periodic circulation of air after deactivation of
the cooling elements, but, instead, just a “single-shot” fan
operation for purposes of coil drainage.
    Similar to Petrone, Nakatsuno discloses a system
wherein the system fan “may be operated for a length of
time Δt2 a predetermined time Δt1 after the stop of the
compressor.” Nakatsuno col. 10 ll. 7–15 (“the drive and
stop of the indoor fan may be operatively associated with
the drive and stop of the compressor”); see also id. at Fig.
11(a). Unlike Petrone, however, Nakatsuno suggests that
the fan may also be “intermittently driven . . . to im-
prove . . . comfortableness and also to minimize . . . energy
consumption” during periods when there is no call for
heating or cooling from the system. Id. col. 9 l. 67 to col.
10 l. 6.
ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.                  9



                              B.
    Citing KSR International Co. v. Teleflex Inc., 550 U.S.
398, 416–17 (2007), Emerson argues that claims 1–5 of
the ’017 patent would have been obvious because they
represent a “combination of familiar elements according
to known methods” that does no more than “yield predict-
able results.” As it did in the district court, Emerson
focuses on the “recycle control” limitation in the last
paragraph of claim 1, since the parties agree that the
other limitations of claim 1, as well as the added limita-
tions of claims 2–5, were known in the prior art. In that
regard, Emerson contends that Mr. Rudd admitted at
trial that the motivation for “recycle control,” as well as
the means for implementing “recycle control,” were known
in the art. Emerson states that Mr. Rudd admitted that a
pause immediately following the end of a cooling cycle is
necessary to prevent moisture from blowing back into the
system. Emerson also states that Mr. Rudd conceded that
having a fan run periodically after the end of a cooling
cycle would necessarily save energy when compared to
running a fan continuously in a “constant fan mode.”
    Emerson contends that Cornelius, Vogelzang, and
Nakatsuno all disclose a periodic fan used to circulate air
to keep the air uniform in the air conditioned space, just
as in claim 1 of the ’017 patent. Specifically, it states that
Cornelius teaches a timer used to operate the system fan
at predetermined intervals to maintain a desirable tem-
perature; that Vogelzang indicates that periodically
cycling the fan when there is no call for heating or cooling
can move air throughout the space to prevent stagnation;
and that Nakatsuno discloses a fan that can be run in-
termittently to improve comfort and conserve energy.
Emerson points out that its expert, Dr. Sherman, testified
that those three references all address the same air
stagnation problem set forth in the ’017 patent.
10                ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.



     Emerson further urges that a person of ordinary skill
would have been motivated to combine the prior art
periodic fans of Cornelius, Nakatsuno, and Vogelzang
with prior art timers to begin air circulation after an
initial pause or delay. It reasons that if a person of ordi-
nary skill had been assembling a thermostat in conjunc-
tion with the prior art periodic fan of Cornelius or
Vogelzang, he or she would naturally have caused the fan
to operate intermittently after the call for heating or
cooling ended. Emerson contends that, since there would
have been no need for the fan to circulate air immediately
after the call for heating or cooling ended, as a matter of
common sense, one of skill in the art would have inserted
a pause before additional circulation was initiated.
Moreover, in Emerson’s view, Petrone and Nakatsuno
both teach a delay or pause in fan operation following the
end of a heating or cooling cycle as being dependent on
the time at which the heating or cooling cycle ends.
Emerson therefore argues that under a proper application
of KSR no reasonable jury could have found the asserted
claims of the ’017 patent not obvious, and the district
court thus erred in denying its motion for JMOL.
    In response, ABT first states that Emerson’s appeal is
an attempt to retry credibility and factual determinations
made by the jury. It argues that, in view of its verdict,
the jury necessarily found ABT’s witnesses, Mr. Rudd and
Dr. Siegel, more credible than Emerson’s technical expert,
Dr. Sherman, and its prior art expert, Mr. Vogelzang. It
contends also that the jury implicitly found that second-
ary considerations of obviousness, such as long-felt need,
weighed in its favor. ABT asserts that the jury’s decision
to credit its witnesses and to find secondary indicia of
nonobviousness is supported by substantial evidence.
     Rather than mounting a strong challenge to the mer-
its of Emerson’s theory of obviousness based on the disclo-
sures of the prior art references, ABT takes the position
that Emerson’s argument is flawed because the references
ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.                 11



upon which it relies are either non-enabled or teach away.
ABT first contends that Nakatsuno and Cornelius are
non-enabling and, therefore, cannot be fully factored into
the obviousness analysis. Nakatsuno, it argues, only
teaches “single-shot” fan operation after a cooling system
compressor deactivates. It states that Nakatsuno does
not enable multiple, periodic fan cycles because only a
single fan cycle is disclosed in the specification. Continu-
ing, ABT argues that, like Nakatsuno, Cornelius is non-
enabling because it does not disclose any electrical con-
nection between the thermostat that controls the call for
fan activation and the timer used to create periodic cycles
based on the end of heating. It states that the timer of
Cornelius is not synced with the deactivation of the heat-
ing device, since the “timing device” operates “inde-
pendently of temperature conditions.” Cornelius col. 1 ll.
46–50. Relatedly, ABT states that Vogelzang fails to
disclose the periodic fan cycle being dependent on the last
heating or cooling cycle. Finally, it urges that Nakatsuno
and Petrone—the so-called “single-shot” fan operation
references—teach away because they are for a purpose
(i.e., coil drainage) “unrelated” to the benefits described in
the ’017 patent. Because ABT believes that Cornelius,
Nakatsuno, Vogelzang, and Petrone are non-enabled or
teach away, it argues that a person of skill in the art
would have had no reason to combine their teachings.
                             III.
    Having considered the parties’ arguments and the ev-
idence of record, we hold, as a matter of law, that the
district court erred in denying Emerson’s motion for
JMOL that claims 1–5 of the ’017 patent are invalid as
obvious.
                              A.
    Recognizing that nonobviousness was determined by a
jury, we assign due deference to the jury’s verdict. In
analyzing the jury’s decision, “[w]e first presume that the
12                 ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.



jury resolved the underlying factual disputes in favor of
the verdict [] and leave those presumed findings undis-
turbed if they are supported by substantial evidence.”
Kinetic Concepts, 688 F.3d at 1356–57 (quoting Jurgens v.
McKasy, 927 F.2d 1552, 1557 (Fed. Cir. 1991)). Next, we
“examine the [ultimate] legal conclusion [of nonobvious-
ness] de novo to see whether it is correct in light of the
presumed jury fact findings.”        Id. at 1357 (quoting
Jurgens, 927 F.2d at 1557) (second alteration added). In
recreating the facts as they may have been found by the
jury, and in applying the Graham factors, “we assess the
record evidence in the light most favorable to the verdict
winner.” Richardson-Vicks, Inc. v. Upjohn Co., 122 F.3d
1476, 1479 (Fed. Cir. 1997). The Graham factors are: (1)
the scope and content of the prior art; (2) the differences
between the prior art and the claims at issue; (3) the level
of ordinary skill in the art at the time of the invention;
and (4) objective evidence of nonobviousness. Graham v.
John Deere Co., 383 U.S. 1, 17–18 (1966). In this case,
there are few, if any, relevant differences between the
parties’ understanding of the scope and content of the
prior art, the differences between the prior art and the
claims, and the level of ordinary skill in the art.
    As seen, the issue of nonobviousness revolves around
the “recycle control” limitation of claim 1. That limitation
reads as follows:
     [A] recycle control for periodically activating and
     deactivating only the circulating fan after a prese-
     lected time period, since the central air condition-
     ing system has been deactivated, or the circulating
     fan has been deactivated from the selectable con-
     stant fan mode.
’017 patent claim 1 (emphases added).
    Both ABT’s expert, Dr. Siegel, and Emerson’s expert,
Dr. Sherman, agreed that Nakatsuno discusses intermit-
tent or periodic cycling, but only directly teaches a “single-
ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.                13



shot” fan cycle after a predetermined delay following
deactivation of the central air system. Dr. Siegel, ex-
plained that “[s]o that is to say there is not a periodic
recycling of the fan [disclosed in Nakatsuno]. There is a
single time after the air conditioning has finished its job
of cooling, satisfied the thermostat, where the fan shuts
off one time to allow the coil to drain.” Trial Tr. at
107:18–22, ABT Sys., No. 4:11-cv-00374-AGF (E.D. Mo.
Feb. 20, 2013), ECF No. 486. Nakatsuno, according to Dr.
Siegel, addresses the problem of draining the coils after a
cooling cycle. Dr. Siegel acknowledged, however, that
Nakatsuno discusses “intermittent fan operation.” Id. at
155:4–21. Dr. Siegel testified similarly with respect to the
Petrone reference—and Dr. Sherman did not disagree:
that it only discloses a “single-shot” fan for purposes of
coiling drainage. Dr. Siegel’s testimony is supported by
the record; we must therefore presume that the jury
resolved any factual disputes about Nakatsuno’s and
Petrone’s “single-shot” fan operation in ABT’s favor.
Thus, a reasonable juror could have found that, while
technology for activating a fan after a predetermined time
period following the end of a heating or cooling cycle
existed in the prior art, it may have been implemented as
a single event at the end of a cooling cycle for purposes of
draining cooling coils.
    The experts also were in general agreement with re-
gard to the prior art teaching periodic fan cycling during a
period where there is no call for heating or cooling. Dr.
Siegel testified that the timers of Cornelius and Vogel-
zang are not described as being directly associated with,
or linked to, the end of a heating or cooling cycle. Fur-
ther, both Dr. Siegel and Dr. Sherman agreed that the
timer of Cornelius is not explicitly reset after the end of a
heating or cooling cycle. In that regard, Dr. Siegel ex-
plained that Cornelius’s timer “could make the fan go on
and off on a predetermined cycle but it couldn’t control
that -- couldn’t link that to the operation of the thermo-
14                ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.



stat or the rest of the system.” Id. at 112:17–20. In other
words, according to Dr. Siegel, Cornelius does not teach
“activating and deactivating only the circulating fan after
a preselected time period, since the central air condition-
ing system has been deactivated,” as set forth in claim 1.
Vogelzang likewise does not teach a periodic fan that
operates as a function of when a heating or cooling cycle
ends. Like Cornelius, Vogelzang discloses a timer that
may be unassociated with the deactivation of the heating
and cooling cycles.
                            B.
     In view of the undisputed facts, as well as those that
are presumed to have been resolved by the jury in ABT’s
favor, the issue of obviousness thus turns on whether, at
the time of the Rudd invention, a person of ordinary skill
would have combined elements from the several prior art
references. Specifically, the question is whether a person
of skill would have combined references that disclose
“single-shot” fan operation as a function of the time when
heating or cooling cycles end with references that teach
periodic fan cycles during periods of time when there is no
call for heating or cooling.
    Dr. Siegel testified that there would have been no mo-
tivation to combine elements of Cornelius and/or Vogel-
zang with Petrone and/or Nakatsuno to create a periodic
fan cycle that was dependent on the end of a cooling or
heating cycle. In his view, the references do not explain
how a person of skill might “plug[]” the “single-shot” fan
references into the periodic cycle references, and he stated
that there would be logistical and enablement issues in
making a “single-shot” system work with “heating, con-
stant fan and cooling” modes. Id. at 116:20–118:22. Dr.
Siegel also testified that the prior art references do not
show the control logic required by the claims of the ’017
patent. In response, Dr. Sherman took the position that it
would have been a logical and ordinary step for a person
ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.                   15



of skill in the art to use the prior art to create a periodic
fan that is dependent on the end of a heating or cooling
cycle.
    The parties agree that Vogelzang sets forth every lim-
itation of asserted claim 1 except tying periodic fan cycles
directly to the deactivation of the heating or cooling
elements or to the end of “constant mode” operation.
Indeed, Vogelzang addresses the same problem identified
by the ’017 patent (i.e., air stagnation during periods
without heating or cooling) in a nearly identical manner.
Vogelzang discloses a “cycle position” option for a thermo-
stat having a “conventional fan cycler . . . connected to
energize the fan relay” so that it can “maintain periodic
air flow through the air cleaner 30 and . . . move the air
about in the space.” Vogelzang col. 2 ll. 36–42. Vogelzang
also describes energizing the relay for a “predetermined
number of times each hour to cycle fan relay 33 such as[]
6 short operations each hour.” Id. col. 2 ll. 43–46. The
reason for this, the patent explains, is to cycle the fan
“during periods when there is no operation of the heating
apparatus or cooling apparatus” in order to “provide for
the treatment of the air through by [sic] the air cleaner.”
Id. col. 1 ll. 32–38. Vogelzang, though, does not necessari-
ly start the periodic cycle based on the deactivation of the
heating and cooling elements.
    For its part, Cornelius discloses elements similar to
Vogelzang. It teaches a furnace that works in conjunction
with a thermostat and a timing device “to intermittently
start and stop the [circulation fan] motor 14 for ventilat-
ing a room or rooms when the room thermostat 110 does
not call for heat.” Cornelius col. 9 ll. 23–26. As in Vogel-
zang and the ’017 patent, the stated purpose of the inven-
tion is to address stagnation, temperature, and
cleanliness. Id. col. 9 ll. 40–42; see also id. col. 9 ll. 26–34
(“In particular this scheme is adapted for the ventilation
of sleeping rooms where the windows remain closed
during the night and when the room thermostat is manu-
16                  ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.



ally or automatically lowered to produce a temperature of,
say, 55° F. There are many nights when the furnace
would not operate as the house would not cool to this
temperature.”). Cornelius does not, however, disclose a
“constant fan mode,” as required by claim 1. And, it does
not teach necessarily setting the timing device as a func-
tion of the end of a heating cycle.
    Nakatsuno, however, does disclose operation of a sys-
tem fan at a predetermined time following the deactiva-
tion of an air conditioning compressor. Nakatsuno states,
in relevant part:
     As far as the intermittent operation of the indoor
     fan is concerned, the drive and stop of the indoor
     fan may be operatively associated with the drive
     and stop of the compressor as shown in FIG. 11(a)
     and, alternatively, the indoor fan may be operated
     for a length of time Δt2 a predetermined time Δt1
     after the stop of the compressor as shown in FIG.
     11(b).
Nakatsuno col. 10 ll. 7–15 (emphases added); see also id.
at Figs. 11(a), (b). Nakatsuno thus discloses using the
end of a cooling cycle as part of the function for turning on
the system fan during periods where there is no call for
heating or cooling. Additionally, even presuming that
Nakatsuno fails to disclose periodic fan cycles by only
specifically describing a “single-shot” fan, it plainly sug-
gests such cycles:
     [An] indoor fan can be intermittently driven at the
     predetermined number of revolution [sic] regard-
     less of whether the compressor is being operated
     or held still, so that the difference between respec-
     tive temperatures in top and bottom regions in the
     space to be air-conditioned can be minimized by
     the circulation effect thereby to improve the com-
     fortableness and also to minimize the energy con-
     sumption.
ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.                17



Id. col. 9 l. 67 to col. 10 l. 6 (emphasis added). 1
    In KSR, the Supreme Court instructed that “when a
patent claims a structure already known in the prior art
that is altered by the mere substitution of one element for
another known in the field, the combination must do more
than yield a predictable result.” 550 U.S. at 416. The
Court stated that “[i]f a person of ordinary skill can
implement a predictable variation [of a prior art reference
with other prior art components], § 103 likely bars its
patentability.” Id. at 417. Here, the timer of Vogelzang
or Cornelius, modified by the predetermined and com-
pressor-dependent interval of Nakatsuno or Petrone,
would have yielded a predictable result: the system fan
would activate periodically following the end of a heating
or cooling cycle—the invention claimed in the ’017 pa-
tent. 2



    1    Petrone teaches a fan that stops when the call for
cooling ends and restarts after a predetermined interval.
However, it does not teach such operation for the purpose
of alleviating air stagnation. Rather, it teaches a delay
for purposes of allowing the cooling coils to drain conden-
sation. Petrone col. 4 ll. 18–22, col. 7 ll. 7–15.
     2   The cited references do not “teach away,” as ABT
argues, because it is clear that none come near to “‘criti-
ciz[ing], discredit[ing], or otherwise discourag[ing]’ inves-
tigation into the invention claimed.” DePuy Spine, Inc. v.
Medtronic Sofamor Danek, Inc., 567 F.3d 1314, 1327 (Fed.
Cir. 2009) (quoting In re Fulton, 391 F.3d 1195, 1201
(Fed. Cir. 2004)). Additionally, ABT’s suggestion that
Cornelius and Nakatsuno are non-enabled is misplaced,
since even “[a] non-enabling reference may qualify as
prior art for the purpose of determining obviousness,”
Symbol Tech., Inc. v. Opticon, Inc., 935 F.2d 1569, 1578
(Fed. Cir. 1991), and even “an inoperative device . . . is
prior art for all that it teaches,” Beckman Instruments,
18                 ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.



    It is well settled that, even where references do not
explicitly convey a motivation to combine, “any need or
problem known in the field of endeavor at the time of
invention and addressed by the patent can provide a
reason for combining the elements in the manner
claimed.” Id. at 420. We have made clear that “a
court . . . may find a motivation to combine prior art
references in the nature of the problem to be solved.”
Ruiz v. A.B. Chance Co., 357 F.3d 1270, 1276 (Fed. Cir.
2004). As pertinent here, “this form of motivation to
combine evidence is particularly relevant with simpler
mechanical technologies.” Id.; see also Pro-Mold & Tool
Co., Inc. v. Great Lakes Plastics, Inc., 75 F.3d 1568, 1573
(Fed. Cir. 1996).
    In our view, if, at the time of the invention claimed in
the ’017 patent, a person of ordinary skill had looked at
Vogelzang, he or she would have found it nearly obvious
from that disclosure itself to set the periodic fan to run as
a function of when the heating or cooling cycle ended.
That is because the nature of the problem to be solved in
both the ’017 patent and Vogelzang (as well as Cornelius
and Nakatsuno) is to alleviate air stagnation during
periods of no heating or cooling. As Dr. Sherman testi-
fied, “a person of ordinary skill would realize that the
easiest and best thing to do would be to start with an off
period, a delay before doing this cycling since the purpose
is to mix the air and the air has just been mixed.” Trial
Tr. at 69:20–25, ABT Sys., No. 4:11-cv-00374-AGF (E.D.
Mo. Feb. 19, 2013), ECF No. 485. Thus, setting a delay
timer or control based on the end of the heating or cooling
cycle, similar to the concept in Nakatsuno or Petrone,
would have been naturally implemented by a person
skilled in the art. In other words, it would have been



Inc. v. LKB Produkter AB, 892 F.2d 1547, 1551 (Fed. Cir.
1989).
ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.                19



obvious to set the timer of Vogelzang or Cornelius based
on the end of a heating or cooling cycle, as disclosed in
Nakatsuno (or Petrone), regardless of for how long the
time interval was to be set.
                              C.
    The fourth Graham factor, objective evidence of non-
obviousness, includes factors such as “commercial success,
long-felt but unresolved need, failure of others, copying,
and unexpected results.” Ruiz v. A.B. Chance Co., 234
F.3d 654, 663 (Fed. Cir. 2000); see also id. at 667 (explain-
ing that “secondary considerations, when present, must be
considered in determining obviousness”). As noted, in
arguing in support of the district court’s denial of Emer-
son’s JMOL motion, ABT relies on the considerations of
commercial success and long-felt need, the latter of which
was cited by the district court in its opinion. ABT Sys.,
2013 WL 5567713, at *3. We are not persuaded by ABT’s
argument.
    ABT’s reliance on commercial success is undermined
as a matter of law by ABT’s failure to introduce evidence
related to the nexus between periodic fan operation and
the commercial success of products embodying the inven-
tion claimed in the ’017 patent. See Demaco Corp. v. F.
Von Langsdorff Licensing Ltd., 851 F.2d 1387, 1391 (Fed.
Cir. 1988) (explaining that “nexus” is used to “designate a
legally and factually sufficient connection between the
proven success and the patented invention”). The items
that ABT presented as evidence in support of its commer-
cial success argument were, in large part, advertisements
and press releases for Mr. Rudd’s products, not market
share information or industry praise or recognition for the
novelty of the fan recycler feature claimed in the ’017
patent. See In re Huang, 100 F.3d 135, 140 (Fed. Cir.
1996) (“This court has noted in the past that evidence
related solely to the number of units sold provides a very
weak showing of commercial success, if any.”); Demaco,
20                ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.



851 F.2d at 1392 (“When the thing that is commercially
successful is not coextensive with the patented inven-
tion . . . the patentee must show prima facie a legally
sufficient relationship between that which is patented
and that which is sold.”). Also, there is no evidence in the
record that Emerson’s products were sold as a result of
the Big Blue’s CFF recycler feature. The record is thus
lacking evidence that the alleged success of Emerson’s
product in the market was driven by any novel aspect of
the claimed invention. J.T. Eaton & Co. v. Atl. Paste &
Glue Co., 106 F.3d 1563, 1571 (Fed. Cir. 1997)
(“[C]ommercial success of the product must be due to the
merits of the claimed invention beyond what was readily
available in the prior art.”).
    We are also not persuaded by ABT’s argument that
commercial success is demonstrated by the number of
licenses taken under the ’017 patent. While licenses can
sometimes tilt in favor of validity in close cases, they
cannot by themselves overcome a convincing case of
invalidity without showing a clear nexus to the claimed
invention. Iron Grip Barbell Co. v. USA Sports, Inc., 392
F.3d 1317, 1324 (Fed. Cir. 2004) (“Our cases specifically
require affirmative evidence of nexus where the evidence
of commercial success presented is a license, because it is
often ‘cheaper to take licenses than to defend infringe-
ment suits.’”); SIBIA Neurosciences, Inc. v. Cadus Pharm.
Corp., 225 F.3d 1349, 1358 (Fed. Cir. 2000) (“[T]he mere
existence of these licenses is insufficient to overcome the
conclusion of obviousness, as based on the express teach-
ings in the prior art that would have motivated one of
ordinary skill to modify [other prior art].”). Here, ABT
points to no evidence that the licenses it cites were taken
based on the merits of the invention claimed in the ’017
patent. See Iron Grip, 392 F.3d at 1324.
    ABT’s argument that there was a long-felt need for
the invention embodied in the claims of the ’017 patent
likewise does not lead us to a different result. The disclo-
ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.                 21



sures of the prior art references—and especially Vogel-
zang’s “cycle position” option for running a system fan
“during periods when there is no operation of the heating
apparatus or cooling apparatus” to help mix air—
eliminate any serious contention that there was a long-
felt need for the invention claimed in the ’017 patent. See
Ormco Corp. v. Align Tech., Inc., 463 F.3d 1299, 1311–12
(Fed. Cir. 2006) (“[I]f the feature that creates the commer-
cial success was known in the prior art, the success is not
pertinent.”). ABT’s argument of a long-felt need ignores
the scope of claim 1, which does not set forth limits on
how long or how often periodic fan operation is to be
performed. In addition, claim 1 does not limit in any way
the control logic for implementing such periodic operation.
                              D.
    In sum, even assuming that the jury correctly re-
solved pertinent factual disputes in favor of ABT, the
prior art still renders the claims of the ’017 patent obvious
as a matter of law. See Boston Sci. Scimed, Inc. v. Cordis
Corp., 554 F.3d 982, 990 (Fed. Cir. 2009) (“When we
consider that, even in light of a jury’s findings of fact, the
references demonstrate an invention to have been obvi-
ous, we may reverse its obviousness determination.”);
Richardson-Vicks, 122 F.3d at 1479 (a jury verdict “does
not mean that we are free to abdicate our role as the
ultimate decision maker on the question of obviousness.
That decision remains within our province”). Here, all of
the claimed limitations are expressly found in the cited
prior art references. At the same time, the motivation or
rationale for combining those references can be found in
the nature of the problem addressed, if not directly from
the disclosures of the references themselves. Finally,
ABT’s argument based upon secondary considerations of
nonobviousness is not supported by the record. Thus, we
hold that claims 1–5 of the ’017 patent are invalid as a
matter of law by reason of obviousness.
22                 ABT SYSTEMS, LLC   v. EMERSON ELECTRIC CO.



                        CONCLUSION
    For the foregoing reasons, we vacate the district
court’s denial of Emerson’s JMOL motion and reverse the
judgment that claims 1–5 of the ’017 patent are not
invalid as obvious. We also vacate the judgment of in-
fringement. The case is remanded to the district court for
entry of judgment in favor of Emerson and dismissal of
ABT’s complaint.
     REVERSED-IN-PART, VACATED-IN-PART, and
                  REMANDED
                           COSTS
     Each party shall bear its own costs.
