Kioxia Corporation, Kioxia America, Inc. v. Viasat, Inc.

NOTE: This disposition is nonprecedential.
United States Court of Appeals
for the Federal Circuit
______________________
KIOXIA CORPORATION, KIOXIA AMERICA, INC.,
Appellants
v.
VIASAT, INC.,
Appellee
______________________
2024-1384
______________________
Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. IPR2022-
01067.
______________________
Decided: December 19, 2025
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MICHAEL HAWES, Baker Botts LLP, Houston, TX, ar-
gued for appellants.
MEG E. FASULO, Bartlit Beck LLP, Chicago, IL, argued
for appellee. Also represented by MATTHEW R. FORD, NEVIN
M. GEWERTZ, JOHN SCOTT MCBRIDE, RAVI SHAH; NOSSON
KNOBLOCH, Denver, CO; DAVID ZIMMER, Zimmer, Citron &
Clarke LLP, Cambridge, MA.
______________________
Case: 24-1384 Document: 45 Page: 1 Filed: 12/19/2025

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KIOXIA CORPORATION v. VIASAT, INC. 2
Before CHEN, BRYSON, and CUNNINGHAM, Circuit Judges.
CHEN, Circuit Judge.
Kioxia Corporation and Kioxia America, Inc. (Kioxia)
appeal the final written decision of the Patent Trial and
Appeal Board (Board) in an inter partes review (IPR) up-
holding claims 1–4, 8, 10–19, and 23–25 of Viasat, Inc.’s
(Viasat’s) U.S. Patent No. 8,615,700 (’700 patent) as not
unpatentable. Kioxia Corp. v. Viasat, Inc., No. IPR2022-
01067, 2023 WL 8039801 (P.T.A.B. Nov. 20, 2023) (Deci-
sion). This appeal is now moot as to claims 1, 4, 8, 15, 17,
and 19, which were cancelled after being found unpatenta-
ble in a separate IPR proceeding. As to the remaining chal-
lenged claims 2, 10–14, 16, and 23–25,1 we affirm.
BACKGROUND
The ’700 patent discloses methods, systems, and de-
vices for forward error correction in flash memory. Claims
1 and 15 illustrate the limitations at issue in this appeal.
Claim 1 requires “a decoding module configured to . . . de-
code the received encoded data to generate a plurality of
partially decoded data streams,” and claim 15 similarly re-
cites “a decoder . . . configured to[] retrieve the encoded
data from flash memory to generate a plurality of data
streams.” ’700 patent at claims 1, 15 (emphases added).
Kioxia filed an IPR petition challenging claims 1–4, 8,
10–19, and 23–25 of the ’700 patent as unpatentable under
35 U.S.C. §§ 102–03. In its final written decision, the
Board found that the challenged claims were not unpatent-
able, in part because Lee2 did not disclose the required “de-
code” or “decoder” limitations of claims 1 and 15.
1 Kioxia does not appeal the Board’s rejection of its
unpatentability contentions of claims 3 and 18. See Kioxia
Op. Br. 4.
2 U.S. Patent No. 7,865,809 (Lee).
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KIOXIA CORPORATION v. VIASAT, INC. 3
A separate IPR proceeding found claims 1, 4, 8, 15, 17,
and 19 to be unpatentable, and the ’700 patent was subse-
quently amended to cancel those claims. This appeal is
therefore moot as to the cancelled claims. See XY, LLC v.
Trans Ova Genetics, L.C., 890 F.3d 1282, 1294 (Fed. Cir.
2018). The remaining claims on appeal (claims 2, 10–14,
16, and 23–25) all depend from cancelled independent
claims 1, 15, or 17.
Because Kioxia’s appeal arguments as to the remain-
ing, challenged dependent claims focus only on limitations
found in those independent claims, our analysis need only
address those claims. We have jurisdiction pursuant to 28
U.S.C. § 1295(a)(4)(A).
DISCUSSION
Regarding claim 1, Kioxia argues on appeal that the
Board erred by construing “decode the encoded data” to
mean “distinguish error correction bits from information
bits in the received encoded data,” such that “buffering” is
excluded from “decoding.” We are not persuaded.
“A claim term should be given its ordinary meaning in
the pertinent context, unless the patentee has made clear
its adoption of a different definition or otherwise dis-
claimed that meaning.” Ancora Techs., Inc. v. Apple, Inc.,
744 F.3d 732, 734 (Fed. Cir. 2014). Applying that principle,
the Board properly construed “decode” to mean the oppo-
site of “encode,” i.e., “distinguish error correction bits from
information bits in the received encoded data.” Decision,
2023 WL 8039801, at *6–7. In support, the Board relied on
the ’700 patent’s description of “encoding” as “adding parity
information,” such as error correction bits, to information
to be stored in flash memory. Id. at *6 (citing ’700 patent,
col. 3 ll. 46–48). The Board further explained that the par-
ties did not dispute that the established meaning in the art
for “decoding” is the opposite of “encoding” and that the un-
disputed meaning was supported by expert testimony and
dictionary definitions. Id.
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KIOXIA CORPORATION v. VIASAT, INC. 4
The Board further explained that mere buffering—
“us[ing] a region of memory to hold data that is waiting to
be transferred”—“would not undo or reverse any previous
encoding and would not be sufficient, by itself, to constitute
decoding.” Id. This conclusion was confirmed by Kioxia’s
expert, who acknowledged that “[d]ecoding might include
buffering, but buffering by itself would not be considered
decoding to a person of ordinary skill.” Id.3
Kioxia contends that “buffering” can constitute “decod-
ing” in the context of the ’700 patent, relying primarily on
a sentence from the patent specification: “[i]n one embodi-
ment, the decoder module processor may buffer, de-inter-
leave, or perform certain aspects of the decoding process,
an [sic] thereby generate decoded (or partially decoded)
data streams.” ’700 patent col. 6 ll. 9–14 (emphases added).
This passage, however, describes “buffer[ing]” as one oper-
ation that a “decoder module processor” may perform, not
that buffering alone constitutes decoding. Moreover, this
passage does not make clear that the patentee intended to
depart from the plain and ordinary meaning of “decode,”
which excludes buffering alone. See Ancora Techs., 744
3 On appeal, Kioxia argues that it does not contend
that “mere buffering” amounts to decoding. Kioxia Op. Br.
21. But Kioxia’s proposed construction does exactly that by
listing buffering as a type of decoding: “buffer the received
encoded data, de-interleave the received encoded data, or
distinguish error correction from information bits in the re-
ceived encoded data.” Id. (emphases added). Kioxia’s at-
tempt to avoid this result by tying buffering to
“generat[ing] a plurality of data streams” conflates “de-
code” with a separate claim element that the Board never
construed. See Decision, 2023 WL 8039801, at *7. Under
Kioxia’s proposed construction, mere buffering alone would
constitute decoding.
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KIOXIA CORPORATION v. VIASAT, INC. 5
F.3d at 734. Accordingly, the Board did not err in its con-
struction of “decode” for claim 1.
Kioxia also argues that the Board erred by applying its
claim 1 analysis to claim 15’s “decoder,” which, unlike
claim 1’s “decoding module,” need not perform the function
of “decoding.” See Kioxia Reply Br. 5; Oral Arg. at 8:09–
13:59 (available at https://www.cafc.uscourts.gov/oral-ar-
guments/24-1384_11052025.mp3) (Oral Arg.). Because Ki-
oxia did not raise this argument in its opening brief, it is
forfeited. See Quanergy Sys., Inc. v. Velodyne Lidar USA,
Inc., 24 F.4th 1406, 1415 n.6 (Fed. Cir. 2022) (party’s fail-
ure to challenge Board’s findings in opening brief consti-
tuted forfeiture); SmithKline Beecham Corp. v. Apotex
Corp., 439 F.3d 1312, 1319 (Fed. Cir. 2006).
On top of that, Kioxia’s late-raised argument conflicts
with what it told the Board: the Board relied on its claim
1 analysis to reject Kioxia’s claim 15 argument because Ki-
oxia itself expressly linked the two analyses in the Petition.
See J.A. 116 (For claim 15[c]: “As explained supra
§§VIII.A.1.b-c [claim 1 analysis], Lee discloses a de-
coder . . . ”). Indeed, in its opening brief, Kioxia again re-
peatedly linked “decode” from claim 1 to “decoder” from
claim 15 and relied on that linkage to argue that the
Board’s alleged error in its claim 1 analysis carried over to
claim 15. See, e.g., Kioxia Op. Br. 2, 3, 15–16, 18, 27. Yet,
in its reply brief, Kioxia reversed course, contending that
the Board independently erred by relying on its claim 1
analysis for claim 15—a position directly at odds with its
opening brief. Compare Kioxia Reply Br. 5, with Kioxia Op.
Br. 27. That argument is therefore forfeited in light of how
Kioxia has chosen to litigate the issue. Because buffering
alone cannot satisfy claim 15’s “decoder” limitation, we re-
ject Kioxia’s opening brief argument that relies on Lee’s
page buffer 504 for performing a decoding function. See
Kioxia Op. Br. 27.
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KIOXIA CORPORATION v. VIASAT, INC. 6
Finally, Kioxia challenges the Board’s interpretation of
claims 15 and 17, which require “retriev[ing] the encoded
data from flash memory” and “receiving encoded data from
a flash memory comprising a plurality of data streams,” re-
spectively. ’700 patent at claims 15, 17. Kioxia argues that
the Board improperly interpreted these limitations to add
a limitation not supported by the intrinsic record—namely,
that the decoder directly receives encoded data from flash
memory. Kioxia Reply Br. 7–9, 14–15.4 However, this ar-
gument is also forfeited because Kioxia did not sufficiently
develop it in its opening brief. See Rodriguez v. Dep’t of
Veterans Affs., 8 F.4th 1290, 1305 (Fed. Cir. 2021) (argu-
ments that are merely alluded to and not developed in a
party’s brief are generally not considered on appeal);
SmithKline, 439 F.3d at 1319.
We have considered Kioxia’s remaining arguments and
find them unpersuasive. For the foregoing reasons, we af-
firm.
AFFIRMED
4 Kioxia’s argument that Lee’s page buffer 504 is
part of claim 15’s “decoder” when combined with Lee’s de-
coder 530 is forfeited because Kioxia did not raise it in its
opening brief. Compare Kioxia Op. Br. 27, with Kioxia Re-
ply Br. 5–6.
Case: 24-1384 Document: 45 Page: 6 Filed: 12/19/2025

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