Court Opinion

ID: 9556728
Source: CourtListenerOpinion
Date Created: 2023-08-18 14:01:29.090247+00
Date Added: 2024-06-11T09:01:10.773426
License: Public Domain

Case: 21-1992   Document: 43     Page: 1   Filed: 08/18/2023

        NOTE: This disposition is nonprecedential.

   United States Court of Appeals
       for the Federal Circuit
                 ______________________

          UNIVERSAL ELECTRONICS, INC.,
                    Appellant

                            v.

                      ROKU, INC.,
                        Appellee
                 ______________________

             2021-1992, 2021-1993, 2021-1994
                 ______________________

     Appeals from the United States Patent and Trademark
 Office, Patent Trial and Appeal Board in Nos. IPR2019-
 01612, IPR2019-01613, IPR2019-01614.
                  ______________________

                Decided: August 18, 2023
                 ______________________

     MICHAEL ANTHONY NICODEMA, Greenberg Traurig
 LLP, West Palm Beach, FL, argued for appellant. Also rep-
 resented by BENJAMIN GILFORD, JAMES J. LUKAS, JR., Chi-
 cago, IL.

    JON WRIGHT, Sterne Kessler Goldstein & Fox, PLLC,
 Washington, DC, argued for appellee. Also represented by
 RICHARD CRUDO, LESTIN KENTON; JONATHAN DANIEL
 BAKER, Dickinson Wright PLLC, Mountain View, CA;
 MICHAEL DAVID SAUNDERS, Austin, TX.
Case: 21-1992    Document: 43      Page: 2    Filed: 08/18/2023

 2                  UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.

                  ______________________

     Before NEWMAN, REYNA, and STOLL, Circuit Judges.
 NEWMAN, Circuit Judge.
     This is a consolidated appeal of three Inter Partes Re-
 view (“IPR”) petitions filed by Roku, Inc., for three patents
 derived from the same parent application and owned by
 Universal Electronics, Inc. (“UEI”). The Patent Trial and
 Appeal Board (“Board”) held that claims 1–4, 6, 8, 9, and
 22–25 of U.S. Patent No. 7,589,642 (“the ’642 patent”);
 claims 2–5, 7–13, and 15 of U.S. Patent No. 8,004,389 (“the
 ’389 patent”); and claims 1–5 of U.S. Patent No. 9,911,325
 (“the ’325 patent”) are unpatentable on the ground of obvi-
 ousness. 1 The Board upheld challenged claim 14 of the ’389
 and claim 7 of the ’325 patent; Roku does not cross-appeal
 those rulings.
     For the reasons we discuss, we affirm the Board’s deci-
 sions in all three IPRs.
                        BACKGROUND
                The Patented Inventions
     The three UEI patents are entitled “Relaying Key Code
 Signals Through a Remote Control Device,” and state that
 they relate “generally to remote control devices and, more
 specifically, to relaying key code signals through a remote
 control device to operate an electronic consumer device . . .

     1   Roku, Inc. v. Universal Elecs., Inc., No. IPR2019-
 01612, 2021 WL 1192127 (P.T.A.B. Mar. 29, 2021); No.
 IPR2019-01613, 2021 WL 1192128 (P.T.A.B. Mar. 29,
 2021); No. IPR2019-01614, 2021 WL 1395255 (P.T.A.B.
 Apr. 13, 2021). The Board issued analogous opinions for all
 three reviews. Citations to “Board Op.” are to IPR2019-
 01612 unless otherwise noted.
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 UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.                    3

 such as televisions, stereo radios, digital video disk players,
 video cassette recorders, set-top cable television boxes and
 set-top satellite boxes.” ’642 patent, col. 1, ll. 6–16. 2
     The patents discuss problems accompanying the provi-
 sion and use of electronic remote control technology:
     A remote control device typically controls a selected
     electronic consumer device by transmitting infra-
     red key code signals to the selected electronic con-
     sumer device. The infrared signals contain key
     codes of a codeset associated with the selected elec-
     tronic consumer device. Each key code corresponds
     to a function of the selected electronic device, such
     as power on, power off, volume up, volume down,
     play, stop, select, channel up, channel down, etc. In
     order to avoid the situation where a remote control
     device unintentionally operates an electronic con-
     sumer device that is associated with a different re-
     mote control device, manufacturers sometimes use
     distinct codesets for the communication between
     various electronic consumer devices and their asso-
     ciated remote control devices.
 Id., col. 1, ll. 21–34. The patents’ written descriptions elab-
 orate on these problems and describe a method to relay a
 key code through a “remote control device to control a se-
 lected one of multiple different electronic consumer devices
 without requiring the codeset associated with the selected
 electronic consumer device to be stored on the remote con-
 trol device.” Id., col. 1, ll. 51–55.
     The representative claim for each patent is as follows:

     2   The ’325 patent is a continuation of the ’389 patent,
 which is a continuation of the ’642 patent. The specifica-
 tions are the same. Unless otherwise noted the citations
 are to the ’642 patent.
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 4                UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.

     [’642 patent] Claim 1. A method comprising:
        (a) receiving a keystroke indicator signal from
             a remote control device, wherein the key-
             stroke indicator signal indicates a key on
             said remote control device that a user has
             selected;
        (b) generating a key code within a key code gen-
             erator device using the keystroke indictor
             signal;
        (c) modulating said key code onto a carrier sig-
            nal, thereby generating a key code signal;
            and
        (d) transmitting said key code signal from said
             key code generator device to said remote
             control device.
     [’389 patent] Claim 2. A method comprising:
        (a) receiving a keystroke indicator signal from
             a remote control device, wherein the key-
             stroke indicator signal indicates a key on
             said remote control device that a user has
             selected;
        (b) generating a key code within a key code gen-
             erator device using the keystroke indicator
             signal, wherein said key code is part of a
             codeset that controls an electronic con-
             sumer device;
        (c) modulating said key code onto a carrier sig-
            nal, thereby generating a key code signal;
        (d) transmitting said key code signal from said
             key code generator device; and
        (e) identifying said codeset using input from a
             user of said remote control device, wherein
             said codeset is identified when said user
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 UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.                   5

            stops pressing a key on said remote control
            device.
    [’325 patent] Claim 1. A first device for transmit-
    ting a command to control a functional operation
    of a second device, the first device comprising:
        a receiver;
        a transmitter;
        a processing device coupled to the receiver and
            the transmitter; and
        a memory storing instructions executable by
           the processing device, the instructions
           causing the processing device to:
        generate a key code using a keystroke indicator
           received from a third device in communica-
           tion with first device via use of the receiver,
           the keystroke indicator having data that
           indicates an input element of the third de-
           vice that has been activated;
        format the key code for transmission to the sec-
            ond device; and
        transmit the formatted key code to the second
            device in a key code signal via use of the
            transmitter;
        wherein the generated key code comprises a
           one of a plurality of key code data stored in
           a codeset, wherein the one of the plurality
           of key code data is selected from the codeset
           as a function of the keystroke indicator re-
           ceived from the third device, wherein each
           of the plurality of key code data stored in
           the codeset comprises a series of digital
           ones and/or digital zeros, and wherein the
           codeset further comprises time information
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 6                 UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.

            that describes how a digital one and/or a
            digital zero within the selected one of the
            plurality of key code data is to be repre-
            sented in the key code signal to be trans-
            mitted to the second device.
     UEI appeals as to all the invalidated claims, arguing
 that the Board erred in holding that a skilled artisan would
 have been motivated to combine known wireless transmis-
 sion technology with known modulation techniques.
                  The Cited References
     Roku filed separate petitions for IPR of the three pa-
 tents, citing Mishra, Rye, and Caris as primary references
 for relevant wireless transmission technology, combined
 with Dubil and Skerlos as references regarding relevant
 modulation techniques. UEI argues that the Board misun-
 derstood and misconstrued the references, that the Board
 erred in finding a motivation to combine the references,
 and that the combination of references does not teach the
 inventions claimed in the UEI patents.
                              A
           Wireless transmission of key codes
     The Mishra, Rye, and Caris references relate to the
 wireless transmission of key codes:
        Mishra, U.S. Patent Pub. No. 2001/0005197
     The Mishra reference is titled, “Remotely Controlling
 Electronic Devices,” and describes “a way to program a re-
 mote control unit to handle a variety of electronic devices
 in a fashion which is easy and quick for the user.” Id. at ¶
 5. The Mishra Abstract summarizes:
     A control system enables telephone calls to be an-
     swered remotely using a remote control unit also
     adapted to remotely control an electronic device
     such as VCR. A processor based station may
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 UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.                   7

     communicate with a remote control unit using both
     infrared and radio frequency protocols to enable re-
     mote telephone communications and remote con-
     trol of electronic devices.
        Rye, U.S. Patent Pub. No. US2004/0080428
     The Rye reference is titled, “RF Audiovisual Compo-
 nent Remote Control System,” and states that the object is
 “to provide a remote control system for use in controlling
 the operation of a multi-brand audiovisual component sys-
 tem that is cost effective and reliable.” Id. at ¶ 12. Its Ab-
 stract summarizes:
     A handheld remote control unit transmits binary
     coded rf address and control signals to an address-
     able transceiver where those signals are detected,
     decoded and processed to derive binary coded con-
     trol signals that are coded in accordance with the
     brands or manufacturers of the audiovisual compo-
     nents that are to be controlled along with the func-
     tion that is to be thus controlled for the addressed
     components.
          Caris, U.S. Patent No. 7,562,128 B1
      The Caris reference is titled, “STB Connects Remote to
 Web Site for Customized Code Downloads,” and “addresses
 perceived disadvantages in conventional programming of a
 remote control to be used with consumer electronics equip-
 ment.” Board Op. at *13. Caris discusses the need for sim-
 plifying the process of configuring a remote for use with
 different pieces of equipment. ’128 patent, col. 3, ll. 37–42.
 The Abstract summarizes:
     A set top box (STB) is marketed together with a
     programmable remote. The remote has a dedicated
     button to connect the STB to a specific server on
     the Internet. The consumer can notify the server
     of his/her other CE equipment, which he/she de-
     sires to be controllable through the same remote as
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 8                 UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.

     the one that came with the STB. The server down-
     loads to the STB data representative of the rele-
     vant control codes. The STB is provided with
     means to program the remote with these codes. In
     return the server has obtained detailed and accu-
     rate information about this consumer’s equipment.
     A reliable customer base can thus be built for
     streamlining Help Desk operations.
                              B
                 Modulation techniques
     Dubil and Skerlos describe the transmission of control
 codes using known modulation techniques.
            Dubil, U.S. Patent No. 8,132,105 B1
     The Dubil reference is titled, “Control Codes for Pro-
 grammable Remote Supplied in XML Format” and “relates
 to remote control devices and to a service for enabling the
 programming of remote controls to be used with consumer
 electronics (“CE”) equipment.” Id., col. 1, ll. 6–8. The Ab-
 stract describes the subject matter:
     An Internet service makes available control codes
     for use on a programmable universal remote. The
     remote controls CE equipment through IR or RF
     commands. A server supplies the control codes as
     XML data that gets processed at the receiver’s set
     top box or PC, or the remote itself, for being
     properly installed on the remote.
     The Board found that Dubil teaches “different modula-
 tion schemes that may be used in transmitting control
 codes having different bit patterns, including frequency-
 shift keying (“FSK”), binary phase-shift keying (“BPSK”),
 and pulse-width modulation (“PWM”).” Board Op. at *13.
 Dubil states that “[t]he invention covers both the usage of
 XML for IR or RF codes and for the GUI. The codes can be
 described using a number of parameters defined by XML
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 UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.                    9

 tags. Examples have been mentioned above: carrier fre-
 quency, duty cycle, protocol type (FSK, biphase, PWM,
 etc.), repetition time, on/off[.]” Dubil, col. 4, ll. 33–37.
             Skerlos, U.S. Patent No. 4,426,662
      The Skerlos reference is titled, “IR Remote Control De-
 tector/Decoder,” and “relates to remote control receivers
 and more specifically is directed to an infrared (IR) remote
 control detector/decoder providing improved noise immun-
 ity particularly adapted for use with a television receiver.”
 Id., col. 1, ll. 5–9. The Abstract describes the subject mat-
 ter:
     A pulse code modulated (PCM) infrared (IR) remote
     control detector/decoder with improved noise im-
     munity particularly adapted for use with a televi-
     sion receiver is disclosed. The IR pulses are
     modulated by means of a high frequency dock sig-
     nal in translating the transmitted signal to a
     higher frequency, more noise immune portion of
     the IR spectrum. After receipt of the transmitted
     signal by a signal detector, the high frequency mod-
     ulation is removed from the pulses which are then
     decoded. Under the control of a microcomputer, the
     decoder looks for the start data bit and, if received,
     the subsequent control instructions. When the
     data transmission has been decoded, the microcom-
     puter activates the appropriate control outputs to
     the television receiver’s tuner system to achieve
     the desired control function.
 Skerlos explains that “[t]he present invention is utilized
 with a remote control system in which pulse code modu-
 lated (PCM) output signals are generated in response to
 user operated controls.” Id., col. 2, l. 67–col. 3, l. 2.
                         DISCUSSION
     Obviousness is a question of law, based on underlying
 factual findings. In re NTP, Inc., 654 F.3d 1279, 1297 (Fed.
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 10                 UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.

 Cir. 2011). On appeal from the Board, we review factual
 findings for support by substantial evidence and review le-
 gal conclusions de novo. Gen. Elec. Co. v. Raytheon Techs.
 Corp., 983 F.3d 1334, 1345 (Fed. Cir. 2020). Substantial
 evidence is “such relevant evidence as a reasonable mind
 might accept as adequate to support a conclusion.” Consol.
 Edison Co. v. NLRB, 305 U.S. 197, 229 (1938).
     Patent claim construction is a question of law that the
 court reviews de novo. Trs. Of Columbia Univ. v. Symantec
 Corp., 811 F.3d 1359, 1362 (Fed. Cir. 2016) (citing Teva
 Pharm. USA, Inc. v. Sandoz, Inc., 574 U.S. 318 (2015))
 (“The construction of claim terms based on the claim lan-
 guage, the specification, and the prosecution history are le-
 gal determinations.”). When claim construction involves
 underlying factual findings, these findings are reviewed for
 support by substantial evidence. Knowles Elecs. LLC v.
 Cirrus Logic, Inc., 883 F.3d 1358, 1361–62, 1364 (Fed. Cir.
 2018).
                   Claim Construction
      The Board invalidated various claims based on its con-
 struction of certain claim terms. UEI argues that the
 Board erred in construing and applying four terms: (A) the
 “generating” term relating to the key code of the ’642 pa-
 tent and the ’389 patent (“generating a key code within a
 key code generator device using the keystroke indicator
 signal”); (B) the “means” term in the ’389 patent (“means
 for receiving a key code from said RF receiver and for send-
 ing said key code to said IR transmitter such that said key
 code is modulated onto an IR carrier signal”); (C) the “pro-
 cessing device” term in the ’325 patent (“causing the pro-
 cessing device to: generate a key code . . . format the key
 code . . . and transmit the formatted key code”); and (D) the
 “timing information” term in the ’642 and ’325 patents
 (“codeset further comprises time information”).
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 UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.                 11

                              A
            The term “generating a key code”
     The Board held claims 1–4, 6, 8, 9, and 22–25 of the
 ’642 patent and claims 2–3 of the ’389 patent obvious over
 Mishra or Rye in combination with Dubil. UEI states that
 the Board erroneously construed “generating a key code
 within a key code generator device using the keystroke in-
 dicator signal” and that the Board’s construction is incon-
 sistent with the plain language of the claims and with the
 undisputed construction of the “key code generator device.”
 UEI Br. 2–3.
     UEI argues that the specifications and prosecution his-
 tories of the ’642 and ’389 patents state the correct con-
 struction and that “[t]he Board’s finding that Mishra and
 Rye disclose ‘generating a key code within a key code gen-
 erator device using the keystroke indicator signal’ is based
 on a construction of that limitation that includes ‘receiving
 an appliance control code and merely translating or con-
 verting the code into another format, such as an infrared
 signal.’” Id. at 44.
      UEI argues that under the correct construction “[n]ei-
 ther Mishra nor Rye discloses ’generating a key code within
 a key code generator device using the keystroke indicator
 signal.’” Id. at 50. UEI states that the Board found that
 “Mishra and Rye disclose merely ‘translating’ or ‘convert-
 ing’ a received key code into another format.” Id. UEI em-
 phasizes that “the correct construction of the limitation
 ‘generating a key code within a key code generator device
 using the keystroke indicator signal’ excludes ‘translating’
 or ‘converting’ a received key code into another format.” Id.
     Roku responds that the “generating” limitation as con-
 strued by the Board does not exclude translating or con-
 verting a key code into another format, and that “[t]he
 Board properly construed this limitation consistent with its
 plain and ordinary meaning to encompass scenarios where
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 12                  UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.

 the set-top box (1) translates a keystroke indicator signal
 received from a remote control into a format appropriate
 for controlling a consumer device, as disclosed in Mishra;
 and (2) uses the received keystroke indicator signal to ob-
 tain the corresponding key code from a look-up table and
 converts the signal to the appropriate code, as disclosed in
 Rye and Caris.” Roku Br. 38–39. We discern no error in
 the Board’s statement:
      We are not persuaded that there is sufficient basis
      for construing the “generating” limitation so
      broadly as to capture the identification of a key
      code from a codeset while simultaneously excluding
      translation of a received code. By forgoing a
      straightforward recitation of “identifying” in the
      claims in favor of a broader recitation of “generat-
      ing,” the patentee clearly meant for the term not to
      be limited to mere identification of a key code but
      also to include other forms of generation of the key
      code.
 Board Op. at *11.
     Substantial evidence supports the Board’s finding that
 each of Mishra, Rye, and Caris discloses the “generating”
 limitation under the Board’s construction. Mishra gener-
 ates a key code signal by translating a command signal re-
 ceived from the remote control into a format suitable for
 controlling a device. The Board explained for claim 1 of the
 ’642 patent:
      Independent claim 1 recites “generating a key code
      within a key code generator device using the key-
      stroke indicator signal.” Petitioner contends that
      this limitation is disclosed by Mishra’s determina-
      tion of a corresponding control code through trans-
      lation of the command signal received from the
      RCU into a format appropriate for controlling an
      appliance . . . . In accordance with our adopted con-
      struction of the limitation, we agree that such
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 UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.                   13

     translation qualifies as “generating a key code,”
     and that Mishra therefore meets the limitation.
 Board Op. at *15 (internal citations omitted).
     Rye describes converting an input control signal to be
 compatible with the operating binary code for the selected
 audiovisual component. The Board applied Rye to claim 2
 of the ’642 patent:
     Like independent claim l, independent claim 2 re-
     cites “generating a key code within a key code gen-
     erator device using the keystroke indicator signal.”
     Petitioner contends that this limitation is disclosed
     by Rye’s procedure of “convert[ing] the input con-
     trol signal so that it is compatible with the operat-
     ing binary code for the selected audiovisual
     component whose IR remote control code is ob-
     tained from the look-up table 46.”
 Board Op. at *21 (internal citations omitted).
     UEI argued to the Board that “Rye’s converting of a re-
 ceived control code was expressly disclaimed from ‘gener-
 ating a key code’ during prosecution.” Id. (quoting UEI
 Board Br. 40) The Board stated that “we disagree that
 there was an effective prosecution history disclaimer that
 limits the scope of the ‘generating’ limitation as Patent
 Owner proposes.” Id. Roku states that “UEI makes a sim-
 ilar argument on appeal. While UEI tries to disguise its
 true argument by not using the word ‘disclaimer’ in its
 brief, its invitation for the Court to depart from the ordi-
 nary meaning of ‘generating’ is obviously premised on a
 disclaimer theory.” Roku Br. 43. However, we are not di-
 rected to a disclaimer, and none is cited. A disclaimer of a
 legal right should be clear and explicit. See Trivascular,
 Inc. v. Samuels, 812 F.3d 1056, 1063–64 (Fed. Cir. 2016)
 (“The party seeking to invoke prosecution history dis-
 claimer bears the burden of proving the existence of a ‘clear
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 14                 UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.

 and unmistakable’ disclaimer that would have been evi-
 dent to one skilled in the art.”).
     The Board found that both Mishra and Rye disclose the
 “generating” limitation, Board Op. at *15, *21, and that
 Caris generates a key code signal by identifying the corre-
 sponding code from a look-up table, id. at *27. Substantial
 evidence supports the Board’s findings that Mishra, Rye,
 and Caris disclose generating a key code by converting or
 translating a received signal, as the term is used in claims
 1–4, 6, 8, 9, and 22–25 of the ’642 patent and claims 2 and
 3 of the ’389 patent. We conclude that the Board correctly
 applied these references to the claim term “generating a
 key code.”
                              B
       The term “means for receiving a key code”
     The “means” limitation, “means for receiving a key
 code from said RF receiver and for sending said key code to
 said IR transmitter such that said key code is modulated
 onto an IR carrier signal,” appears in claims 12–15 of the
 ’389 patent. UEI argues that the Board erred in holding
 these claims obvious based on Mishra in combination with
 Dubil, and also based on Caris in combination with Skerlos
 and Yazolino (U.S. Patent No. 5,329,370). UEI Br. 3–4.
     UEI states that the Board’s construction of the “means”
 limitation is legally erroneous, and that Roku’s combina-
 tions of references does not disclose this limitation under
 the proper construction. Id.
     The means-plus-function provision of Title 35 (previ-
 ously § 112(6)) states:
      § 112(f) Element in Claim for a Combina-
      tion.—
      An element in a claim for a combination may be ex-
      pressed as a means or step for performing a speci-
      fied function without the recital of structure,
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     material, or acts in support thereof, and such claim
     shall be construed to cover the corresponding struc-
     ture, material, or acts described in the specification
     and equivalents thereof.
 This provision “allows a patentee to recite a function to be
 performed as a claim limitation rather than reciting struc-
 ture or materials for performing that function.” Omega
 Eng’g, Inc. v. Raytek Corp., 334 F.3d 1314, 1321 (Fed. Cir.
 2003). Analysis of a means-plus-function limitation follows
 an established protocol:
     The construction of a means-plus-function limita-
     tion follows a two-step approach. First, we must
     identify the claimed function, staying true to the
     claim language and the limitations expressly re-
     cited by the claims. Once the functions performed
     by the claimed means are identified, we must then
     ascertain the corresponding structures in the writ-
     ten description that perform those functions. A dis-
     closed structure is corresponding “only if the
     specification or the prosecution history clearly
     links or associates that structure to the function re-
     cited in the claim.” In other words, the structure
     must be necessary to perform the claimed function.
 Id. (internal citations omitted).
     The parties agree that the claimed function is “receiv-
 ing a key code from said RF receiver and for sending said
 key code to said IR transmitter such that said key code is
 modulated onto an IR carrier signal.” Board Op. (’389 pa-
 tent) at *12. Construing the recited means, the Board
 adopted Roku’s proposed construction: “a microcontroller
 that performs the algorithm of receiving a key code from an
 RF receiver that has received a first key code signal and
 translating the key code so that the key code is modulated
 onto an infrared carrier signal resulting in a second key
 code signal.” Id. at *14. This construction is consistent
 with the specification’s description of the remote control
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 16                  UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.

 that performs the receiving and sending functions. As §
 112(f) provides, the claim scope is limited to the structure
 in the specification and its equivalents. See Aristocrat
 Techs. Austl. Pty v. Int’l Game Tech., 521 F.3d 1328, 1333
 (Fed. Cir. 2008).
      The Board determined that the ’389 patent describes
 the algorithm for the claimed sending and receiving func-
 tions, stating that “Petitioner’s proposed structure goes be-
 yond a mere restatement of the function by including
 specific reference to key code signals and translation of the
 key code. Petitioner supports its proposal by citing to col-
 umn 5, lines 45–59, of the ’389 patent, which makes specific
 reference to the first and second key code signals, as well
 as to ‘translating the communicated key code.’” Board Op.
 (’389 patent) at *13. The specification of the ’389 patent
 illustrates:
              Next (step 104), an RF transmitter 20 of
      key code generator device 12 transmits first key
      code signal 19 in the form of an RF transmission to
      an RF receiver 21 on remote control device 11.
              Next (step 105), remote control device 11
      receives first key code signal 19 and relays the key
      code communicated by first key code signal 19 to
      VCR 13 in the form of a second key code signal 22.
      Remote control device 11 is a slave to key code gen-
      erator device 12. Remote control device 11 relays
      the key code by receiving first key code signal 19 in
      RF form and translating the communicated key
      code so that the key code is modulated onto a sec-
      ond carrier signal resulting in second key code sig-
      nal 22. In this example, the second carrier signal
      is an infrared signal with a frequency in the range
      between three hundred gigahertz and three hun-
      dred terahertz.
 ’389 patent, col. 5, ll. 45–59. The Board correctly concluded
 that the algorithm for performing the claimed “receiving”
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 UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.                  17

 and “sending” functions is disclosed, for this passage de-
 scribes the claimed means by which the remote control mi-
 crocontroller carries out the function of receiving a key code
 from the RF receiver and sending the code to the IR trans-
 mitter.
     Roku correctly states that “the Board’s articulation of
 the claimed structure, which includes only the particular
 algorithm required to perform the claimed function, is
 faithful to the specification’s own description and con-
 sistent with the extrinsic evidence of record.” Roku Br. 55.
 See Univ. of Pitt. of Commonwealth Sys. Of Higher Educ.
 v. Varian Med. Sys., Inc., 561 F. App’x 934, 941 (Fed. Cir.
 2014) (“The district court properly located the disclosure of
 an algorithm that covered what was necessary to perform
 the claimed function . . . and nothing more . . . . The algo-
 rithm need only include what is necessary to perform the
 claimed function.”).
     UEI argues that “[t]he Board’s finding that Mishra in
 combination with Dubil and Caris in combination with
 Skerlos and Yazolino disclose the Means Limitation should
 also be reversed because it is based on a legally erroneous
 construction of the structure of the Means Limitation as ‘a
 microcontroller that performs the algorithm of receiving a
 key code from an RF receiver that has received a first key
 code signal and translating the key code so that the key
 code is modulated onto an infrared carrier signal resulting
 in a second key code signal.’” UEI Br. 58.
     The Board found that the microcontroller of Mishra
 controls reception of a key code from an RF transceiver and
 transmits the key code with an IR transmitter. And, in
 light of Dubil’s modulating key code techniques, the Board
 concluded that Misha thus teaches the “means for receiv-
 ing a key code.” See Board Op. (’389 patent) at *27 (“For the
 ‘means for receiving a key code,’ Petitioner identifies the
 microcontroller, discussed above in connection with de-
 pendent claim 10, which controls reception of a key code
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 18                  UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.

 from an RF transceiver, and transmits the key code with
 an IR transmitter. Because this identification is sufficient
 under our adopted construction of the ‘means for receiving
 a key code,’ and because Petitioner makes explicit refer-
 ence to its analysis of modulating key codes in light of Du-
 bil, we conclude that Petitioner makes a sufficient
 showing.” (internal citations omitted)).
     The Board made a similar finding regarding the micro-
 controller of the means limitations for Caris in combination
 with Skerlos and Yazolino, stating:
      In addition to Caris and Skerlos, Petitioner relies
      on Yazolino in addressing limitations of claims that
      recite a “microcontroller” in some form . . . . [Roku’s
      expert] testifies that, in Petitioner’s proposed com-
      bination of Caris and Skerlos, the modulation de-
      scribed in Skerlos “would be performed by a
      microcontroller in the remote control,” but that
      “Caris does not explicitly describe these opera-
      tional details.” Petitioner accordingly reasons that
      a person of ordinary skill in the art “would have
      known to look to references, such as Yazolino,
      which explicitly describes the circuitry of a remote
      control such as the one disclosed by Caris.” In light
      of Petitioner’s evidence, we find this reasoning,
      which is supported by rational underpinning, suffi-
      cient to effect the combination of those teachings
      with those of Caris and Skerlos.
 Board Op. (’389 patent) at *31 (internal citations omitted).
     These findings are supported by substantial evidence,
 particularly the disclosures in the cited references as dis-
 cussed above. These findings support the Board’s construc-
 tion. On this construction, UEI does not dispute that
 Mishra in combination with Dubil, and Caris in combina-
 tion with Skerlos and Yazolino, disclose the “means” limi-
 tation. We affirm the Board’s determinations regarding
 this term.
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 UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.                   19

                              C
                The term “processing device”
     The Board found that it would have been obvious to a
 skilled artisan that Caris’ set top box (STB) would include
 a processing device as recited in the processing device lim-
 itation in claims 1–5 of the ’325 patent. Board Op. (’325
 patent) at *20. UEI states that the Board erred. UEI ar-
 gues that “Claim 1 of the ’325 patent recites a ‘processing
 device’ that performs the steps or functions of ‘generat[ing]
 a key code,’ ‘format[ting] the key code,’ and ‘transmit[ting]
 the formatted key code.’” UEI Br. 62. UEI states that
 “Roku conceded that Caris does not disclose that its set-top
 box (“STB”) has a ‘processing device.’” Id.
     UEI states that the Board offered no reasoning to sup-
 port its conclusion that it would have been obvious to mod-
 ify Caris to include a processing device that performs the
 functions of generating, formatting, and transmitting. Id.
 at 62–63. Roku responds with the testimony of its expert,
 Dr. Russ, that “set-top boxes containing such devices for
 processing received commands and transmitting key codes
 were well-known in the art.” Roku Br. 65. Dr. Russ stated:
         Caris describes the functionality of an STB as
     well as a receiver and a transmitter but does not
     explicitly illustrate the processing device of the
     STB that is used for generating a key code and
     transmitting the key code as will be further de-
     scribed below. However, in view of the STB func-
     tionality described in Caris, a POSA would have
     found it obvious that this functionality would have
     been performed using a processing device coupled
     to the receiver and the transmitter. STBs typically
     included processing devices such as processors or
     microcontrollers that controlled the functionality of
     the STBs.
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 20                  UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.

                              ***
          A POSA would have understood that STBs
      would receive a command from a remote control
      and use a processing device to interpret the com-
      mand and identify a corresponding key code. The
      STBs would also identify potential parameters,
      such as modulation and timing parameters, used to
      transmit the key code to another device. A pro-
      cessing device would be used to access memory and
      retrieve the corresponding key code as well as per-
      form the modulation of the key code for transmis-
      sion. Thus, a POSA would have understood that
      Caris’ STB would include a processing device in or-
      der to perform the functions described in Caris.
 Russ Decl. ¶¶ 173, 176 (Appx2334, 2336) (internal citations
 omitted). Dr. Russ provided U.S. Patent No. 6,909,471
 (Bayley), as a reference, and stated: “As illustrated in Bay-
 ley, processing devices in STBs were well-known prior to
 the ’325 patent and executed instructions in memory to re-
 ceive commands and transmit corresponding control
 codes.” Id. at ¶¶ 174–75 (Appx2334–36). The Board stated:
          We credit Dr. Russ’ testimony and are per-
      suaded by Petitioner’s argument and the cited evi-
      dence that, in view of what was well-known to
      ordinarily skilled artisans, it would have been ob-
      vious to a person of ordinary skill in the art that
      Caris’s STB would include a processing device that
      performs the claimed functions, including the func-
      tions to “generate a key code,” “format the key
      code,” and “transmit the formatted key code” and
      that for Caris to perform the claimed functions, the
      STB would include memory storing instructions ex-
      ecuted by the processing device.
 Board Op. at *20.
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 UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.                 21

      We conclude that substantial evidence, including ex-
 pert testimony and the cited references, supports the
 Board’s findings, and that the Board correctly construed
 the processing device limitation.
                                D
              The term “timing information”
     The parties also debate the “timing information” limi-
 tation wherein key code/codeset comprises timing/time in-
 formation. This term is present in claims 4, 9, 23, and 25
 of the ’642 patent and claims 1–5 of the ’325 patent.
     UEI states that substantial evidence does not support
 the Board’s findings that: “(i) Mishra or Rye in combination
 with Dubil and Caris in combination with Skerlos disclose
 the limitation ‘wherein said key code . . . comprises timing
 information’ in challenged claims 4 and 23 of the 642 pa-
 tent; (ii) that Mishra or Rye in combination with Dubil dis-
 closes the limitation ‘wherein said codeset comprises
 timing information’ in challenged claims 9 and 25 of the
 642 patent; and (iii) Caris in combination with Dubil dis-
 closes the limitation ‘wherein the codeset further comprises
 time information’ in challenged claim 1 of the [’]325 pa-
 tent.” UEI Br. 51.
     Claim 4 of the ’642 patent is representative:
     4. The method of claim 1, wherein said key code
     comprises a binary number and timing infor-
     mation, and wherein said timing information de-
     fines how said binary number is modulated in (c)
     onto said carrier signal.
 ’642 patent, col. 10, ll. 36–39.
      UEI argues that the Board simply “adopted Roku’s po-
 sition that Dubil and Skerlos disclose ‘wherein said key
 code comprises . . . timing information’ because the alleged
 timing information in Dubil and Skerlos would purportedly
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 22                  UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.

 be ‘used to modulate a binary number onto a carrier fre-
 quency.’” UEI Br. 51. UEI states that:
      Even if it is true that the timing information in Du-
      bil and Skerlos is used to modulate a key code or
      binary number onto a carrier frequency, this has no
      bearing on whether the key code or codeset com-
      prises timing information, as claimed. Indeed, the
      claims of the Challenged Patents expressly distin-
      guish between a key code or codeset that “com-
      prises timing information,” and using timing
      information to modulate a key code or binary num-
      ber onto a carrier frequency.
 UEI Br. 52–53 (emphases original).
     The Board found that Dubil discloses timing parame-
 ters such as “duty cycle,” “repetition time,” and “on/off
 times of the signal.” Board Op. at *25. Roku’s expert ex-
 plained that Dubil’s “on/off times” define timing for the bi-
 nary numbers of the key codes, wherein “the amount of
 ‘on/off’ time used for each digital one or digital zero would
 describe timing information . . . to define how the binary
 key code would be modulated onto a carrier signal.” Russ
 Decl. ¶ 137 (Appx1091).
     The Board found that a skilled artisan would have con-
 sidered Dubil’s and Skerlos’ teaching of timing information
 “as part of considering the teachings for wireless transmis-
 sion of key codes.” Board Op. at *19, *29. This conclusion
 was supported by the expert testimony that “[i]f a POSA
 did not already understand the formatting of a key code, a
 POSA would look to references” such as Dubil and Skerlos,
 which “describ[e] the format as well as how to transmit the
 key codes using a carrier signal.” Russ Decl. ¶ 139
 (Appx1092). Dr. Russ declared:
      A POSA would understand that the Skerlos
      teaches a key code comprising the timing infor-
      mation because Skerlos uses this the timing
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 UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.                   23

     information described in Skerlos to modulate the
     “bits of coded information” onto a carrier signal. As
     previously explained . . ., this type of modulation
     was well-known and the inclusion of timing infor-
     mation in a key code to modulate the key code onto
     a carrier signal was well-known.
 Id. at ¶230 (Appx1150).
     We conclude that the Board correctly construed the
 “timing information” limitation to conform with existing
 knowledge such as is shown in the Dubil and Skerlos refer-
 ences, which describe the format and transmission of key
 codes using a carrier signal.
                               E
                The combination of references
     The Board found that Mishra, Rye, and Caris describe
 wirelessly transmitting a key code signal from a set-top box
 to a remote control. The Board found that a person of ordi-
 nary skill in this field would have been motivated to com-
 bine known modulation techniques with known wireless
 transmission, for the references are in closely related fields
 of endeavor, and the Board’s conclusion was supported by
 expert testimony and citations to relevant references.
     The parties repeat the debate on this appeal. We con-
 clude that substantial evidence supports the Board’s find-
 ings concerning the combination of references, in turn
 supporting the Board’s conclusion that it would have been
 obvious to a skilled artisan to combine Dubil’s and Skerlos’
 modulation and timing information with the wireless key
 code transmission of Mishra, Rye, and Caris. This conclu-
 sion is founded on the content of the references and the ex-
 pert testimony, and is in accordance with law. We affirm
 the Board’s holding that it would have been obvious to mod-
 ulate the Mishra/Rye/Caris codes as in Dubil and Skerlos.
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 24                UNIVERSAL ELECTRONICS, INC. v. ROKU, INC.

                        CONCLUSION
     We have considered all the arguments concerning
 these three patents and affirm the Board’s decisions of in-
 validity of the claims at issue.
                       AFFIRMED