Case: 19-1169 Document: 52 Page: 1 Filed: 02/04/2020
`
`United States Court of Appeals
`for the Federal Circuit
`______________________
`
`SAMSUNG ELECTRONICS AMERICA, INC.,
`Appellant
`
`v.
`
`PRISUA ENGINEERING CORP.,
`Cross-Appellant
`______________________
`
`2019-1169, 2019-1260
`______________________
`
`Appeals from the United States Patent and Trademark
`Office, Patent Trial and Appeal Board in No. IPR2017-
`01188.
`
`______________________
`
`Decided: February 4, 2020
`______________________
`
`RICHARD L. RAINEY, Covington & Burling LLP, Wash-
`ington, DC, argued for appellant. Also represented by
`KRISTIN COBB, ROBERT JASON FOWLER.
`
` JOHN C. CAREY, Carey, Rodriguez, Greenberg & Paul,
`LLP, Miami, FL, argued for cross-appellant.
` ______________________
`
`Before PROST, Chief Judge, NEWMAN and BRYSON, Circuit
`Judges.
`
`
`
`
`
`

`

`Case: 19-1169 Document: 52 Page: 2 Filed: 02/04/2020
`
`2
`
`SAMSUNG ELECTRONICS AMERICA v. PRISUA ENGINEERING
`CORP.
`
`BRYSON, Circuit Judge.
`Samsung Electronics America, Inc., appeals from a de-
`cision of the Patent Trial and Appeal Board in an inter
`partes review proceeding. Samsung petitioned the Board
`to rule that certain claims of U.S. Patent No. 8,650,591
`(“the ’591 patent”), owned by cross-appellant Prisua Engi-
`neering Corp. (“Prisua”), were unpatentable. At the con-
`clusion of the proceeding, the Board held that claim 11 of
`the ’591 patent was unpatentable based on obviousness.
`However, the Board declined to analyze whether claims 1–
`4 and 8 were unpatentable as anticipated or obvious, be-
`cause it concluded that those claims were indefinite.
`On appeal, Samsung contends that the Board should
`have canceled claims 1–4 and 8 for indefiniteness. In the
`alternative, Samsung argues that even if the Board was
`not statutorily authorized to cancel those claims for indefi-
`niteness, it should have assessed whether they would have
`been anticipated or obvious in view of the cited prior art.
`Prisua cross-appeals from the Board’s ruling that claim 11
`was unpatentable for obviousness. We affirm in part, re-
`verse in part, and remand.
`
`I
`A
`Congress has long permitted parties accused of patent
`infringement in federal court to challenge the validity of
`the asserted patent claims on any ground specified in part
`II of the Patent Act as a condition for patentability and for
`failure to comply with any requirement of 35 U.S.C. § 112.
`See 35 U.S.C. § 282(b)(2)–(3). Over the last few decades,
`Congress has supplemented federal court litigation by cre-
`ating several administrative processes that authorize the
`Patent and Trademark Office (“PTO”) to reconsider and
`cancel wrongly issued claims in some circumstances.
`In 1980, Congress established a regime known as “ex
`parte reexamination.” See Act to Amend the Patent and
`
`

`

`Case: 19-1169 Document: 52 Page: 3 Filed: 02/04/2020
`
`SAMSUNG ELECTRONICS AMERICA v. PRISUA ENGINEERING
`CORP.
`
`3
`
`Trademark Laws, Pub. L. No. 96-517, 94 Stat. 3015 (1980),
`codified at 35 U.S.C. § 301 et seq. Ex parte reexamination
`gives “[a]ny person at any time” the right to “file a request
`for reexamination” based on certain prior art “bearing on
`the patentability” of an already-issued patent. 35 U.S.C.
`§§ 301(a)(1), 302. After institution, an ex parte reexamina-
`tion follows essentially the same back and forth process be-
`tween the patent owner and the examiner as in the initial
`PTO examination. 35 U.S.C. § 305.
`Congress subsequently created a procedure known as
`“inter partes reexamination.” See Optional Inter Partes
`Reexamination Procedure Act of 1999, Pub. L. No. 106-113,
`113 Stat. 1501A-567, codified at 35 U.S.C. § 311 et seq.
`(2006 ed.) (superseded). Inter partes reexamination gave
`third parties greater opportunities to participate in the
`reexamination process, but otherwise proceeded much like
`an ex parte reexamination.
`The Leahy-Smith America Invents Act (“AIA”), Pub. L.
`No. 112-29, 125 Stat. 284 (2011), replaced inter partes
`reexamination with “inter partes review,” the procedure at
`issue in this case. See 35 U.S.C. §§ 311–19. Inter partes
`review, commonly referred to as IPR, provides patent chal-
`lengers with even broader rights to participate in the pro-
`cess of re-evaluating patents, but it also sets limits on the
`process. A petition for inter partes review, for example, can
`request cancellation of claims “only on a ground that could
`be raised under section 102 or 103 [of the Patent Act] and
`only on the basis of prior art consisting of patents or
`printed publications.” 35 U.S.C. § 311(b).
`The AIA also created another administrative process
`called “post-grant review.” See 35 U.S.C. §§ 321–29. Un-
`like a petition for inter partes review, a petition for post-
`grant review can request cancellation of patent claims “on
`any ground that could be raised under paragraph (2) or (3)
`of section 282(b) [of the Patent Act] (relating to invalidity
`of the patent or any claim),” the same invalidity defenses
`
`

`

`Case: 19-1169 Document: 52 Page: 4 Filed: 02/04/2020
`
`4
`
`SAMSUNG ELECTRONICS AMERICA v. PRISUA ENGINEERING
`CORP.
`
`long available to defendants accused of patent infringe-
`ment in federal district court. 35 U.S.C. § 321(b).
`Although a petition for inter partes review is limited to
`a narrow set of grounds, it can be requested at any time
`during a patent’s enforceability period, with certain re-
`strictions. 35 U.S.C. §§ 311(c), 315(b). By contrast, the
`broad range of grounds that may be raised in a post-grant
`review petition are available only for a limited time after
`the patent is issued. 35 U.S.C. § 321(c).
`B
`In 2010, Dr. Yolanda Prieto applied for a patent aimed
`at providing a “new and unique form of enhancing” a user’s
`multimedia entertainment experience. ’591 patent, Ab-
`stract. The PTO granted the application in 2014. The is-
`sued patent, entitled “Video Enabled Digital Devices for
`Embedding User Data in Interactive Applications,” is di-
`rected to “generating an edited video data stream from an
`original video stream” by “substituting at least one object
`. . . in said original video stream by at least a different ob-
`ject.” ’591 patent, col. 1, ll. 43–47. Figure 3 illustrates the
`operation of the video image substitution according to one
`embodiment:
`
`

`

`Case: 19-1169 Document: 52 Page: 5 Filed: 02/04/2020
`
`SAMSUNG ELECTRONICS AMERICA v. PRISUA ENGINEERING
`CORP.
`
`5
`
`As illustrated, a user can insert a selected image, such as
`a face of the user’s choosing, in place of the face of the figure
`in the original video. Id. at col. 3, line 66, through col. 4,
`line 2.
`
`

`

`Case: 19-1169 Document: 52 Page: 6 Filed: 02/04/2020
`
`6
`
`SAMSUNG ELECTRONICS AMERICA v. PRISUA ENGINEERING
`CORP.
`
`Claims 1–4, 8, and 11 of the ’591 patent are at issue in
`this appeal. The claims are directed to methods and appa-
`ratuses for “generating a displayable edited video data
`stream from an original video data stream.” ’591 patent,
`col. 7, ll. 14–16; id. at col. 8, ll. 28–29. Independent claim
`1 reads in full as follows:
`1. An interactive media apparatus for generat-
`ing a displayable edited video data stream from an
`original video data stream, wherein at least one
`pixel in a frame of said original video data stream
`is digitally extracted to form a first image, said first
`image then replaced by a second image resulting
`from a digital extraction of at least one pixel in a
`frame of a user input video data stream, said appa-
`ratus comprising:
`an image capture device capturing the user input
`video data stream;
`an image display device displaying the original
`video stream;
`a data entry device, operably coupled with the im-
`age capture device and the image display device,
`operated by a user to select the at least one pixel in
`the frame of the user input video data stream to use
`as the second image, and further operated by the
`user to select the at least one pixel to use as the
`first image;
`wherein said data entry device is selected from a
`group of devices consisting of: a keyboard, a dis-
`play, a wireless communication capability device,
`and an external memory device;
`a digital processing unit operably coupled with the
`data entry device, said digital processing unit per-
`forming:
`
`

`

`Case: 19-1169 Document: 52 Page: 7 Filed: 02/04/2020
`
`SAMSUNG ELECTRONICS AMERICA v. PRISUA ENGINEERING
`CORP.
`
`7
`
`identifying the selected at least one pixel in the
`frame of the user input video data stream;
`extracting the identified at least one pixel as the
`second image;
`storing the second image in a memory device oper-
`ably coupled with the interactive media apparatus;
`receiving a selection of the first image from the
`original video data stream;
`extracting the first image;
`spatially matching an area of the second image to
`an area of the first image in the original video data
`stream, wherein spatially matching the areas re-
`sults in equal spatial lengths and widths between
`said two spatially matched areas; and
`performing a substitution of the spatially matched
`first image with the spatially matched second im-
`age to generate the displayable edited video data
`stream from the original video data stream.
`’591 patent, cl. 1. Claims 2–4 and 8 depend from claim 1
`and add several limitations that are not pertinent to the
`resolution of this appeal. Independent claim 11 is a method
`claim that tracks the limitations of apparatus claim 1, with
`some minor differences. In particular, claim 11 does not
`have a limitation corresponding to claim 1’s requirement of
`“an image display device displaying the original video
`stream.” Id. On the other hand, claim 11 adds limitations
`that require the computation of “motion vectors associated
`with the first image” and the application of those motion
`vectors “to the second image, wherein the generated dis-
`playable edited video data stream resulting from the sub-
`stitution maintains an overall motion of the original video
`data stream.” Id.
`
`

`

`Case: 19-1169 Document: 52 Page: 8 Filed: 02/04/2020
`
`8
`
`SAMSUNG ELECTRONICS AMERICA v. PRISUA ENGINEERING
`CORP.
`
`C
`After the ’591 patent issued, Dr. Prieto formed Prisua
`to commercialize the invention claimed in the patent. In
`2016, Prisua sued Samsung Electronics America, Inc., and
`several other Samsung entities for patent infringement.
`Prisua alleged that the “Best Face” feature on several Sam-
`sung devices, including cell phones, infringed claims 1, 3,
`4, and 8 of the ’591 patent. The “Best Face” feature, ac-
`cording to Prisua, allowed the accused devices to capture a
`burst of images and then replace unwanted facial images,
`such as images captured when someone was blinking, with
`better images from other frames in the same burst.1
`After being sued, Samsung petitioned for inter partes
`review of claims 1–4, 8, and 11 of the ’591 patent on four
`separate grounds. The Board initially determined that it
`would review only whether a U.S. patent application pub-
`lication known as Sitrick rendered claim 11 obvious. The
`Board declined to institute review of claims 1–4 and 8 on
`any ground, because it concluded that it could not deter-
`mine the scope of those claims.
`The Board concluded that there were two impediments
`to determining the scope of claim 1. First, the Board found
`that it was “unclear whether claim 1 covers, for example,
`an apparatus that includes a data entry device capable of
`being operated by a user to select the at least one pixel, or
`covers only the user actually operating the data entry de-
`vice to select the at least one pixel.” Samsung Elecs. Am.,
`Inc. v. Prisua Eng’g Corp., No. IPR2017-01188, 2017 WL
`
`
`1 After a trial in the United States District Court for
`the Southern District of Florida, the jury found that Sam-
`sung willfully infringed the asserted claims and awarded
`Prisua $4.3 million in damages. That action has been
`stayed pending this proceeding; the verdict in that case is
`not at issue in this appeal.
`
`

`

`Case: 19-1169 Document: 52 Page: 9 Filed: 02/04/2020
`
`SAMSUNG ELECTRONICS AMERICA v. PRISUA ENGINEERING
`CORP.
`
`9
`
`4570373, at *5 (P.T.A.B. Oct. 11, 2017) (“Institution Deci-
`sion”) (emphasis in original). For that reason, the Board
`concluded that claim 1 was indefinite under this court’s de-
`cision in IPXL Holdings, LLC v. Amazon.com, Inc., 430
`F.3d 1377, 1384 (Fed. Cir. 2005). Institution Decision, 2017
`WL 4570373, at *5-6. The Board also concluded that the
`“digital processing unit” limitation in claim 1 “invoke[d]
`§ 112, sixth paragraph” and that the petition failed to iden-
`tify any corresponding structure, as required by section 112
`and the pertinent PTO regulation, 37 C.F.R. § 42.104(b)(3).
`Institution Decision, 2017 WL 4570373 at *6 (citing Wil-
`liamson v. Citrix Online, LLC, 792 F.3d 1339, 1348 (Fed.
`Cir. 2015) (en banc)). The Board found that claims 2–4 and
`8, which depend from claim 1, were indefinite for the same
`reasons. Because the Board determined that it was unable
`to construe claim 1 or dependent claims 2–4 and 8, it con-
`cluded that the petitioner had not “established a reasona-
`ble likelihood of prevailing in showing that claims 1–4, and
`8 are unpatentable under any of the asserted grounds.” Id.
`As the IPR briefing was drawing to a close, the Su-
`preme Court decided SAS Institute, Inc. v. Iancu, 138 S. Ct.
`1348 (2018), in which the Court held that when the Board
`institutes an IPR, it may not pick and choose which claims
`it will address, but must address the patentability of every
`claim challenged by the petitioner. Accordingly, the Board
`modified its institution decision to include all the chal-
`lenged claims and all the grounds presented in the petition.
`The Board also allowed the parties to file supplemental
`briefs and evidence, but only to address the newly added
`claims and grounds.
`In its supplemental briefing, Prisua stated that it did
`not agree with the Board’s indefiniteness determinations.
`Despite that, Prisua argued that because Samsung had
`failed to prove the claims were definite, the Board should
`not apply the prior art to the claims. Prisua also contended
`that the Board did not have the statutory authority to can-
`cel claims for indefiniteness during an IPR.
`
`

`

`Case: 19-1169 Document: 52 Page: 10 Filed: 02/04/2020
`
`10
`
`SAMSUNG ELECTRONICS AMERICA v. PRISUA ENGINEERING
`CORP.
`
`In response, Samsung urged the Board to cancel claims
`1–4 and 8 based on the Board’s determination that those
`claims were indefinite under this court’s analysis in IPXL.
`In the alternative, Samsung argued that even if the Board
`could not cancel the claims for indefiniteness, it could still
`apply the prior art to the claims despite the IPXL issue. In
`support of that contention, Samsung argued that because
`the uncertainty regarding claim scope resulted from the
`combination of two statutory classes of invention, a manu-
`facturer or seller of the claimed device would not know
`when infringement occurred. But that, according to Sam-
`sung, would not pose an obstacle to determining whether
`those claims could be measured against the prior art. Sam-
`sung also argued that the term “digital processing unit”
`constituted a sufficient recitation of structure and did not
`invoke means-plus-function analysis under 35 U.S.C. § 112
`¶ 6.
`In its final written decision, the Board repeated its con-
`clusion that claims 1–4 and 8 were indefinite under IPXL.
`Samsung Elecs. Am., Inc. v. Prisua Eng’g Corp., No.
`IPR2017-01188, 2018 WL 5274000, at *7–8 (P.T.A.B. Oct.
`2, 2018) (“Final Written Decision”). In addition, the Board
`again held that claim 1 and its dependent claims invoked
`section 112, paragraph 6, for the “digital processing unit”
`element, and that because there was no corresponding
`structure in the specification, the Board could not apply the
`prior art to the claims. Id. at *9. The Board therefore held
`that Samsung had not established that claims 1–4 and 8
`were unpatentable under any of the asserted grounds. Id.
`With respect to claim 11, the Board analyzed whether
`that claim would have been obvious in view of Sitrick, the
`sole originally instituted ground of review. After reviewing
`various record materials, including competing expert testi-
`mony, the Board found that all of the limitations of claim
`11 would have been obvious in light of Sitrick, including
`the “digital processing unit” limitation. Id. at *11-19. The
`Board therefore held claim 11 to be unpatentable.
`
`

`

`Case: 19-1169 Document: 52 Page: 11 Filed: 02/04/2020
`
`SAMSUNG ELECTRONICS AMERICA v. PRISUA ENGINEERING
`CORP.
`
`11
`
`II
`On appeal, Samsung challenges the Board’s decision
`not to cancel the claims it found indefinite. In the alterna-
`tive, Samsung contends that the Board should have ap-
`plied the cited prior art to those claims.
`A
`We reject Samsung’s contention that the IPR statute
`authorizes the Board to cancel challenged claims for indef-
`initeness. In Cuozzo Speed Techs., LLC v. Lee, the Su-
`preme Court said the Patent Office would be acting
`“outside its statutory limits” by “canceling a patent claim
`for ‘indefiniteness under § 112’ in inter partes review.” 136
`S. Ct. 2131, 2141–42 (2016). This court subsequently ech-
`oed that view, stating—albeit in a non-precedential opin-
`ion—that “[i]n an IPR, the Board cannot declare claims
`indefinite.” Google LLC v. Network-1 Techs., Inc., 726 F.
`App’x 779, 782 n.3 (Fed. Cir. 2018) (citing 35 U.S.C.
`§ 311(b)); see also Neptune Generics, LLC v. Eli Lilly & Co.,
`921 F.3d 1372, 1378 (Fed Cir. 2019) (holding that the Board
`is not authorized to address challenges to patent eligibility
`under 35 U.S.C. §101 in an IPR proceeding: “Congress ex-
`pressly limited the scope of inter parties review to a subset
`of grounds that can be raised under 35 U.S.C. §§ 102 &
`103.”).
`Samsung asks us to reject those statements as dicta
`and to hold that even though the Board may not institute
`inter partes review based on a claim’s indefiniteness, it
`may cancel such a claim on indefiniteness grounds once it
`has instituted review on statutorily authorized grounds.
`We are not persuaded by Samsung’s arguments; we hold
`that the Board may not cancel claims for indefiniteness in
`an IPR proceeding.
`The statutory provisions governing the inter partes re-
`view process do not permit the Board to institute inter
`partes review of claims for indefiniteness. Section 311(b),
`
`

`

`Case: 19-1169 Document: 52 Page: 12 Filed: 02/04/2020
`
`12
`
`SAMSUNG ELECTRONICS AMERICA v. PRISUA ENGINEERING
`CORP.
`
`entitled “Scope,” states that “[a] petitioner in an inter
`partes review may request to cancel as unpatentable 1 or
`more claims of a patent only on a ground that could be
`raised under section 102 or 103 and only on the basis of
`prior art consisting of patents or printed publications.” 35
`U.S.C. § 311(b). Samsung, the petitioner in the IPR pro-
`ceeding below, was thus not permitted to request that the
`Board cancel claims 1–4 and 8 on the ground that they were
`indefinite.
`Nor could the Board cancel those claims as indefinite
`on its own accord. As the Supreme Court explained in SAS,
`Congress “chose to structure a process in which it’s the pe-
`titioner, not the Director, who gets to define the contours”
`of an IPR proceeding. 138 S. Ct. at 1355. “[T]he statute
`envisions that a petitioner will seek an inter partes review
`of a particular kind—one guided by a petition describing
`‘each claim challenged’ and ‘the grounds on which the chal-
`lenge to each claim is based.’” Id. (quoting 35 U.S.C.
`§ 312(a)(3)). After analyzing the IPR statute and its prede-
`cessors, the Supreme Court concluded that it was clear that
`“the petitioner’s contentions, not the Director’s discretion,
`define the scope of the litigation all the way from institu-
`tion through to conclusion.” Id. at 1357. The petition, that
`is, defines the scope of an IPR proceeding, and nothing in
`the IPR statute permits the Board to expand that scope in
`its final written decision.
`
`1
`Notwithstanding the foregoing authority, Samsung
`points to several provisions in the IPR statute in an effort
`to show that Congress authorized the Board to cancel
`claims for indefiniteness after an IPR has been instituted.
`None of those provisions, however, supports Samsung’s ar-
`gument.
`First, while section 311(b) limits the scope of an IPR
`petition to certain grounds that could be raised under sec-
`tions 102 and 103, Samsung argues that section 318(a),
`
`

`

`Case: 19-1169 Document: 52 Page: 13 Filed: 02/04/2020
`
`SAMSUNG ELECTRONICS AMERICA v. PRISUA ENGINEERING
`CORP.
`
`13
`
`which relates to the Board’s final written decision, is not so
`limited. Section 318(a) directs the Board to “issue a final
`written decision with respect to the patentability of any pa-
`tent claim challenged by the petitioner and any new claim
`added under section 316(d).” 35 U.S.C. § 318(a). Samsung
`contends that the word “patentability” in section 318(a) is
`broader than the phrase “a ground that could be raised un-
`der section 102 or 103” in section 311(b). The difference,
`according to Samsung, indicates that the permissible scope
`of the Board’s final written decision is broader than the
`permissible scope of the petition and the institution deci-
`sion.
`The problem with that argument is that it divorces the
`final written decision provision, section 318(a), from the
`rest of the inter partes review statute. Section 311(b) says
`that a petitioner may ask the Board “to cancel [challenged
`claims] as unpatentable” on certain 102 and 103 grounds.
`In context, it is clear that section 318(a)’s directive to the
`Board to issue a final written decision on the “patentabil-
`ity” of a challenged claim refers back to the grounds on
`which, under section 311(b), the petitioner may request the
`Board to “cancel as unpatentable” claims of the challenged
`patent, i.e., the designated section 102 and 103 grounds.2
`Second, Samsung notes that the word “patentability”
`in section 318(a) modifies both “challenged” claims and
`“new” claims that are proposed during the inter partes pro-
`ceeding. For that reason, Samsung suggests, the scope of
`the Board’s review must be the same for both. And because
`
`2 The Director’s certificate under section 318(b) “con-
`firming any claim of the patent determined to be patenta-
`ble” does not indicate that the Board has analyzed and
`confirmed the patentability of the subject claims against
`any possible ground of invalidity, as Samsung suggests.
`The certificate is merely a reflection of the analysis that
`the Board performed in response to the petition.
`
`

`

`Case: 19-1169 Document: 52 Page: 14 Filed: 02/04/2020
`
`14
`
`SAMSUNG ELECTRONICS AMERICA v. PRISUA ENGINEERING
`CORP.
`
`it is undisputed that the Board may review newly added
`claims for compliance with section 112, Samsung argues
`that the Board must likewise be authorized to review chal-
`lenged claims for unpatentability on section 112 grounds,
`including indefiniteness.
`That argument overlooks the distinction the inter
`partes review statute draws between challenged claims
`and new claims that are added in the IPR proceeding. Sec-
`tion 316(d) allows patent owners to move to amend a patent
`during an IPR proceeding by substituting new or amended
`claims. Unlike section 311(b), section 316(d) does not limit
`the grounds for considering the unpatentability of those
`new claims under provisions other than sections 102 and
`103.
`Because the Board is charged with the responsibility
`under section 318(b) of “incorporating in the patent by op-
`eration of the certificate any new or amended claim deter-
`mined to be patentable,” the Board’s authority with respect
`to new and amended claims necessarily extends to other
`possible grounds of unpatentability, in particular, a failure
`to comply with section 112. Because the statutory provi-
`sions governing challenged claims in an IPR differ im-
`portantly from those governing substitute claims, the term
`“unpatentability” necessarily has a different scope as to
`each.
`Samsung next points to the post-grant review statute
`to support its argument that claims can be cancelled as in-
`definite at the conclusion of an IPR proceeding. Unlike a
`petition for inter partes review, a petition for post-grant re-
`view may be based on “any ground that could be raised un-
`der paragraph (2) or (3) of section 282(b) (relating to
`invalidity of the patent or any claim).” 35 U.S.C. § 321.
`Despite the difference in scope regarding what may be re-
`quested in post-grant review as opposed to inter partes re-
`view, the final written decision provision of the post-grant
`review statute mirrors the final written decision provision
`
`

`

`Case: 19-1169 Document: 52 Page: 15 Filed: 02/04/2020
`
`SAMSUNG ELECTRONICS AMERICA v. PRISUA ENGINEERING
`CORP.
`
`15
`
`of the inter partes review statute. See 35 U.S.C. § 328
`(“[T]he Patent Trial and Appeal Board shall issue a final
`written decision with respect to the patentability of any pa-
`tent claim challenged by the petitioner and any new claim
`added under section 326(d).”) (emphasis added). Because
`there can be no dispute that review of “patentability” in the
`post-grant review statute encompasses indefiniteness,
`Samsung contends that when Congress used the same
`word in the inter partes review statute, it must have meant
`to authorize the Board to consider grounds of unpatenta-
`bility other than those raised in the petition, such as indef-
`initeness.
`To the contrary, the term “patentability” takes its
`meaning in each of the two statutory provisions from its
`particular context. Congress laid out the scope of inter
`partes review in section 311(b), at the beginning of Chapter
`31 of Title 35. It laid out the scope of post-grant review in
`section 321(b), at the beginning of Chapter 32. Congress’s
`use of the word “patentability” in the final written decision
`provision of each chapter—in sections 318(a) and 328(a),
`respectively—most naturally refers to the previously de-
`fined scope of the particular review in question. Patenta-
`bility for purposes of section 318(a) thus refers to the
`limited grounds of unpatentability described in section
`311(b), and patentability for purposes of section 328(a) re-
`fers to the broader grounds of unpatentability described in
`section 321(b).
`
`2
`We also do not agree with Samsung’s contention that
`the Board’s inherent authority to perform claim construc-
`tion during an inter partes review means that the Board
`can cancel the claims as indefinite. Although “indefinite-
`ness analysis involves general claim construction princi-
`ples,” Sonix Tech. Co. v. Publications Int’l, Ltd., 844 F.3d
`1370, 1378 (Fed. Cir. 2017), it does not follow that the
`Board may exceed its statutorily limited authority simply
`
`

`

`Case: 19-1169 Document: 52 Page: 16 Filed: 02/04/2020
`
`16
`
`SAMSUNG ELECTRONICS AMERICA v. PRISUA ENGINEERING
`CORP.
`
`because an indefiniteness issue arises during claim con-
`struction. Instead, as discussed above, Congress viewed a
`challenge based on indefiniteness to be distinct from a chal-
`lenge based on sections 102 and 103. As such, the proper
`course for the Board to follow, if it cannot ascertain the
`scope of a claim with reasonable certainty for purposes of
`assessing patentability, is to decline to institute the IPR or,
`if the indefiniteness issue affects only certain claims, to
`conclude that it could not reach a decision on the merits
`with respect to whether petitioner had established the un-
`patentability of those claims under sections 102 or103.3 It
`would not be proper for the Board to cancel claims on a
`ground that is unavailable in an IPR.
`3
`In essence, Samsung’s argument is that there is no
`limit to the Board’s authority to make unpatentability de-
`terminations at the conclusion of an IPR proceeding. That
`position is at odds with both the statutory language and
`the case law, and we reject it.
`B
`Having rejected Samsung’s argument that the Board
`may cancel challenged claims for indefiniteness during an
`IPR, we next address Samsung’s secondary argument that
`the Board should have assessed the patentability of claims
`1 and 4–8 under sections 102 or 103.
`As noted, even though neither party raised the issue of
`indefiniteness below, the Board raised two indefiniteness
`
`
`3 To be clear, in cases in which the Board cannot
`reach a final decision as to the patentability of certain
`claims because it cannot ascertain the scope of those claims
`with reasonable certainty, the petitioner would not be es-
`topped by 35 U.S.C. § 315(e) from challenging those claims
`under sections 102 or 103 in other proceedings.
`
`

`

`Case: 19-1169 Document: 52 Page: 17 Filed: 02/04/2020
`
`SAMSUNG ELECTRONICS AMERICA v. PRISUA ENGINEERING
`CORP.
`
`17
`
`concerns sua sponte. First, the Board concluded that claim
`1 was indefinite under IPXL, because the claim recited
`both an apparatus and a method of using that apparatus.
`Final Written Decision, 2018 WL 5274000 at *6. Second,
`the Board concluded that the “digital processing unit” lim-
`itation of claim 1 invoked “means-plus-function” claiming
`under 35 U.S.C. § 112, ¶ 6, and that because Samsung did
`not identify any corresponding structure in the specifica-
`tion, the Board could not apply the prior art to claim 1 or
`its dependent claims. Id. Samsung contends that the
`Board’s analysis of the “digital processing unit” limitation
`was incorrect and that the IPXL issue did not prevent the
`Board from assessing the patentability of claims 1 and 4–8
`under sections 102 or 103.
`
`1
`We agree with Samsung that the term “digital pro-
`cessing unit” is not a “means-plus-function” limitation sub-
`ject to analysis under section 112, paragraph 6. Because
`the reference to the digital processing unit does not contain
`the words “means for,” there is a rebuttable presumption
`that section 112, paragraph 6, does not apply to that limi-
`tation. Williamson, 792 F.3d at 1348. That presumption
`can be overcome, but only “if the challenger demonstrates
`that the claim term fails to ‘recite sufficiently definite
`structure’ or else recites ‘function without reciting suffi-
`cient structure for performing that function.’” Id. at 1349.
`The question whether the term “digital processing
`unit” invokes section 112, paragraph 6, depends on
`whether persons skilled in the art would understand the
`claim language to refer to structure, assessed in light of the
`presumption that flows from the drafter’s choice not to em-
`ploy the word “means.” The Board pointed to no evidence
`that a person skilled in the relevant art would regard the
`term “digital processing unit” as purely functional. In fact,
`Prisua argued to the Board, based on testimony from its
`expert (the inventor), that the digital processing unit
`
`

`

`Case: 19-1169 Document: 52 Page: 18 Filed: 02/04/2020
`
`18
`
`SAMSUNG ELECTRONICS AMERICA v. PRISUA ENGINEERING
`CORP.
`
`recited in the claims is “an image processing device that
`people in the art are generally familiar with.” J.A. 896.
`As used in the claims of the ’591 patent, the term “dig-
`ital processing unit” clearly serves as a stand-in for a “gen-
`eral purpose computer” or a “central processing unit,” each
`of which would be understood as a reference to structure in
`this case, not simply any device that can perform a partic-
`ular function. See, e.g., LG Elecs., Inc. v. Bizcom Elecs.,
`Inc., 453 F.3d 1364, 1372 (Fed. Cir. 2006), rev’d on other
`grounds, Quanta Computer, Inc. v. LG Elecs., Inc., 553 U.S.
`617 (2008); Inventio AG v. ThyssenKrupp Elevator Ams.
`Corp., 649 F.3d 1350, 1359 (Fed. Cir. 2011).
`Significantly, that is what the Board found with re-
`spect to the use of the term “digital processing unit” in
`claim 11. Final Written Decision, 2018 WL 5274000, at *14
`(“As a result, we are not persuaded by Patent Owner’s con-
`tention that ‘digital processing unit’ has a narrower defini-
`tion than CPU. Sitrick discloses a general purpose
`computer with a CPU that is capable of performing all of
`the functions recited in claim 11. As a result, we are per-
`suaded that Sitrick’s CPU teaches the recited ‘digital pro-
`cessing unit.’”). Moreover, claim 1 requires that the
`“digital processing unit” be operably connected to a “data
`entry device” such as a keyboard, which in t