Puradigm, LLC v. Dbg Group Investments LLC, Ap Sciences Group, LLC, Fka Activepure Technologies, LLC,…

N OTE: This disposition is nonprecedential.
United States Court of Appeals
for the Federal Circuit
______________________
PURADIGM, LLC,
Plaintiff-Appellant
v.
DBG GROUP INVESTMENTS LLC, AP SCIENCES
GROUP, LLC, FKA ACTIVEPURE
TECHNOLOGIES, LLC, ACTIVEPURE MEDICAL
LLC, AERUS LLC, AERUS FRANCHISING LLC,
ARS HOME SOLUTIONS LLC, AERUS
ENTERPRISE LLC, VOLLARA LLC, VOLLARA
CONCEPTS LLC,
Defendants-Appellees
______________________
2024-2299
______________________
Appeal from the United States District Court for the
Northern District of Texas in No. 3:23-cv-00216-B, Judge
Jane J. Boyle.
______________________
Decided: April 1, 2026
______________________
S COTT P. MCBRIDE, McAndrews, Held & Malloy, Ltd.,
Chicago, IL, argued for plaintiff-appellant. Also repre-
sented by CHRISTOPHER V. CARANI, CHRISTIAN H AVEL
HALLERUD, ANDREW B. K ARP , G REGORY SCHODDE.
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PURADIGM , LLC v. DBG GROUP INVESTMENTS LLC 2
CHAD EDWARD N YDEGGER, Workman Nydegger, Salt
Lake City, UT, argued for defendants-appellees. Also rep-
resented by RYAN C. MORRIS .
______________________
Before P ROST , T ARANTO, and STOLL , Circuit Judges.
P ROST , Circuit Judge.
Puradigm, LLC (“Puradigm”) sued defendants-appel-
les, including DBG Group Investments LLC (“DBG”), in the
U.S. District Court for the Northern District of Texas for
infringing U.S. Patent No. 8,585,979 (“the ’979 patent”).
The district court found the scope of the ’979 patent to be
limited by prosecution history disclaimer and granted sum-
mary judgment of noninfringement. Puradigm, LLC
v. DBG Grp. Invs., LLC, No. 3:23-cv-216, 2024 WL
3997489, at *10 (N.D. Tex. Aug. 29, 2024). For the follow-
ing reasons, we affirm.
BACKGROUND
I
The ’979 patent relates to photo-catalytic cells used for
air purification. ’979 patent Abstract. The patent consists
of two sheets of drawings and a two-page written descrip-
tion. It explains that in typical photo-catalytic cells, ultra-
violet (“UV”) light from an emitter strikes a catalyst-coated
target, producing ions that can eliminate contaminants in
the air. Id. at col. 1 ll. 12–28. The ’979 patent aims to en-
hance such cells so that “a higher proportion of UV energy
. . . can be caused to impinge upon the [target].” Id. at col. 1
ll. 34–36. This is done by adding “reflective surfaces” hav-
ing “unique reflective specifications.” Id. at col. 1 ll. 48–51.
As explained, not just any reflective surface will do:
[I]t is important that reflecting surfaces of the UV
reflector 22 produce surface specular reflection.
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PURADIGM , LLC v. DBG GROUP INVESTMENTS LLC 3
(Specular reflection being a “mirror-like reflection”
of light—in which a single incoming light ray is re-
flected into a single outgoing direction[.]) Specular
reflection is distinct from “diffuse” reflection where
an incoming light ray is reflected into a broad range
of directions. Diffuse reflection may diminish per-
formance enhancement of the photo-catalytic cell
10.
Id. at col. 3 ll. 36–44. The ’979 patent also explains that, to
achieve the above-quoted specification, “it may be neces-
sary to ‘micro-polish or buff’ a selected material[’]s reflec-
tive surface.” Id. at col. 3 ll. 27–30.
II
During prosecution, the examiner rejected the claims
on the basis that Bigelow1 disclosed the claimed “specular
UV reflector.” J.A. 2444–45. The applicant (who later as-
signed the ’979 patent to Puradigm) disagreed, stating
“[n]owhere in Bigelow is anything regarding a specular re-
flector disclosed—either expressly or inherently.”
J.A. 2527.
The examiner was unconvinced, however, and contin-
ued to reject the claims reciting a “specular UV reflector”
based on Bigelow. See J.A. 2548–49. The examiner re-
marked that Bigelow’s “polished aluminum reflector is a
reflector that produces a mirror[-]like reflection” and there-
fore, “Bigelow discloses a specular UV reflector.” J.A. 2556.
The applicant then amended the claims to recite additional
features, but it did not remove the “specular UV reflector”
limitation and said nothing more about it in its response.
J.A. 2576–96. The applicant also stated that, with respect
to the examiner’s statements that Bigelow discloses a
1 U.S. Patent No. 6,500,387 (“Bigelow”).
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PURADIGM , LLC v. DBG GROUP INVESTMENTS LLC 4
specular UV reflector, the applicant “neither agrees nor
disagrees with such statements.” J.A. 2594.
After further amendments, the examiner ultimately al-
lowed the claims because they included “a first specular UV
reflector . . . and a second specular UV reflector,” both being
“configured to reflect UV energy . . . directly to the photo-
catalytic coating” of the first and second targets.
J.A. 2735–36 (emphasis added).
Claim 1 of the ’979 patent recites in relevant part:
1. An apparatus for ionizing air, the apparatus
comprising: . . .
a first reflector arranged on the top portion of the
chamber and configured to:
reflect UV energy emitted along a dimen-
sion towards the first target from a UV
emitter located within the chamber directly
to the photo-catalytic coating of the first
target, wherein the first reflector is a spec-
ular UV reflector, and
reflect UV energy emitted along a dimen-
sion towards the second target from the UV
emitter directly to the photo-catalytic coat-
ing of the second target;
a second reflector arranged on the bottom portion
of the chamber and configured to:
reflect UV energy emitted along a dimen-
sion towards the first target from the UV
emitter located within the chamber directly
to the photo-catalytic coating of the first
target, wherein the second reflector is a
specular UV reflector, and
reflect UV energy emitted along a dimen-
sion towards the second target from the UV
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PURADIGM , LLC v. DBG GROUP INVESTMENTS LLC 5
emitter directly to the photo-catalytic coat-
ing of the second target; . . . .
’979 patent claim 1.
III
Puradigm asserted the ’979 patent against DBG, accus-
ing certain DBG air-purification products of infringement.
DBG sought, and was granted, leave to file an early sum-
mary judgment motion arguing that the ’979 patent is ei-
ther not infringed or is invalid. Puradigm also sought, and
was granted, leave to amend its complaint to modify its list
of accused products. The district court denied without prej-
udice DBG’s summary-judgment motion as moot in light of
the amended complaint. Thereafter, DBG filed a renewed
summary-judgment motion. Puradigm, 2024 WL 3997489,
at *2. The court granted the motion as to noninfringement,
finding that “[t]he prosecution history contains a clear dis-
claimer of polished aluminum because it is not sufficiently
‘specular,’ or ‘mirror-like’” to meet the claimed specular UV
reflector. Id. at *9–10. “As a result, DBG’s unpolished alu-
minum reflectors are also disclaimed from the scope of
‘specular UV reflector’ in [c]laim 1.” Id. at *10. Thus, the
court concluded that no genuine dispute of material fact
precluded granting summary judgment of noninfringement
for DBG.
Puradigm timely appealed. We have jurisdiction under
28 U.S.C. § 1295(a)(1).
D ISCUSSION
On appeal, Puradigm makes two arguments: (1) there
was no prosecution history disclaimer; and (2) the district
court did not properly construe “specular UV reflector.” We
address each in turn.
I
“Whether prosecution history disclaimer applies is a le-
gal question” that we review de novo. Ecolab, Inc. v. FMC
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PURADIGM , LLC v. DBG GROUP INVESTMENTS LLC 6
Corp., 569 F.3d 1335, 1342 (Fed. Cir. 2009). A “clear and
unmistakable surrender of subject matter” is needed to
trigger disclaimer. Id. (quoting Bayer AG v. Elan
Pharm. Rsch. Corp., 212 F.3d 1241, 1251 (Fed. Cir. 2000)).
As discussed below, we conclude that prosecution history
disclaimer applies.
A
We agree with DBG and the district court that the ap-
plicant made a clear and unmistakable disclaimer during
prosecution. The examiner rejected the applicant’s claims
reciting a “specular UV reflector” as anticipated by Bige-
low, which discloses its reflective surfaces (baffles and
chamber walls) being made from polished aluminum to en-
hance UV irradiation. Facing this rejection, the applicant
argued that “[n]owhere in Bigelow is anything regarding a
specular reflector disclosed—either expressly or inher-
ently.” J.A. 2527 (emphasis added). The applicant’s posi-
tion was clear: Bigelow does not explicitly describe its
materials being specular UV reflectors (i.e., expressly), nor
do the materials themselves possess the properties neces-
sary for them to be considered specular UV reflectors (i.e.,
inherently); thus “[n]owhere in Bigelow” is a specular UV
reflector disclosed. Id.
When read in the context of the ’979 patent and its en-
tire prosecution history, the scope and significance of the
applicant’s disclaimer statements come into even sharper
focus. The ’979 patent seeks to enhance the performance
of photo-catalytic cells by capturing and using UV energy
that might be lost because it never reaches the intended
target. ’979 patent col. 1 ll. 34–37. Nearly the entirety of
the limited disclosure of the ’979 patent focuses on the pur-
ported ability of its reflectors to do so. See, e.g., id. at col. 2
ll. 21–25 (The invention can “increase a proportion of emit-
ted UV energy that strikes [the target].”); id. at col. 3
ll. 6–11 (The “presence of the reflectors 22-3 may result in
avoidance of loss of UV energy that might otherwise be
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PURADIGM , LLC v. DBG GROUP INVESTMENTS LLC 7
absorbed or diffused by walls of the chamber 18.”). To
achieve the performance enhancement sought, the patent
emphasizes the importance of its “unique” specular UV re-
flectors exhibiting “mirror-like” reflection as opposed to
“diffuse” reflection. Id. at col. 3 ll. 37–43. As “[d]iffuse re-
flection may diminish performance enhancement of the
photo-catalytic cell 10,” a reflector that does not produce
sufficient specular reflection (and instead produces too
much diffuse reflection) would be antithetical to the ’979
patent. Id. at col. 3 ll. 43–44.
Indeed, the claims of the ’979 patent were only allowed
once they were amended to recite both: (1) the first and sec-
ond reflectors are “specular UV reflectors”; and (2) the first
and second reflectors are each configured to “reflect UV en-
ergy . . . directly to the photo-catalytic coating” of the first
and second targets. Id. at claim 1 (emphasis added). In
combination with the “specular” nature of the reflectors,
this directional relationship further confirms that a crucial
aspect of the claimed invention is the specular UV reflec-
tors producing mirror-like reflection of light, as opposed to
diffuse reflection, so that a higher proportion of light
reaches the targets.
Diffuse reflection, in the applicant’s own words, dimin-
ishes performance because light rays are distributed in a
“broad range of directions,” rather than a single outgoing
direction. Id. at col. 3 ll. 37–44. Due to their indiscriminate
scattering, diffuse reflectors would hinder the directing of
light to the intended target. This point is driven home by
the applicant’s attempt to distinguish Bigelow for lacking
specular UV reflectors. Although Bigelow’s reflectors un-
doubtedly reflect some UV light, they do not, according to
the applicant, possess the inherent properties necessary to
be considered specular UV reflectors. J.A. 2527. One of
ordinary skill in the art, reviewing this prosecution history,
would thus conclude that the applicant considered Bige-
low’s reflectors to produce too much diffuse reflection to be
specular UV reflectors.
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PURADIGM , LLC v. DBG GROUP INVESTMENTS LLC 8
B
Puradigm first argues that because the examiner re-
jected the applicant’s attempt to distinguish Bigelow, there
was no disclaimer. This argument is unpersuasive.
“An applicant’s argument made during prosecution
may lead to a disavowal of claim scope even if the
[e]xaminer did not rely on the argument.” Seachange Int’l,
Inc. v. C-COR, Inc., 413 F.3d 1361, 1374 (Fed. Cir. 2005).
Thus, even if the examiner rejected the applicant’s initial
attempt to distinguish Bigelow, it does not necessarily fol-
low that we must disregard the applicant’s statements. As
discussed above, considering the ’979 patent and its prose-
cution history as a whole, the applicant made a clear and
unmistakable disclaimer with respect to Bigelow. Indeed,
“the interested public has the right to rely on the inventor’s
statements made during prosecution, without attempting
to decipher whether the examiner relied on them, or how
much weight they were given.” Fenner Invs., Ltd. v. Cellco
P’ship, 778 F.3d 1320, 1325 (Fed. Cir. 2015).
Puradigm argues that it would be inequitable to apply
prosecution history disclaimer because the examiner re-
jected the applicant’s urging for a narrower construction of
“specular UV reflector.” Appellant’s Br. 13–14 (citing
Power Integrations, Inc. v. ON Semiconductor Corp., 396
F. Supp. 3d 851 (N.D. Cal. 2019)). Not only does Power In-
tegrations not bind us, but it also presents different facts.
Here, the examiner’s basis for allowance of the claims was
not completely independent from the applicant’s earlier ar-
gument. See Power Integrations, 396 F. Supp. 3d at 865–66
(distinguishing cases where the examiner “reli[ed] on some
alternative argument made by the patentee”). Instead, the
examiner allowed the claims because they recited first and
second reflectors being “specular UV reflector[s]” and that
both are configured to reflect UV energy “directly to the
photo-catalytic coating” of the first and second targets.
J.A. 2735–36. As explained above, the ability of the
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PURADIGM , LLC v. DBG GROUP INVESTMENTS LLC 9
claimed reflectors to reflect UV energy “directly to” their
intended target necessarily depends on their specular na-
ture, a quality the applicant insisted was lacking in Bige-
low. We cannot be sure from this record that the
applicant’s disclaimer statements regarding Bigelow had
no effect on the examiner.
What is clear, however, is that the applicant’s state-
ments in distinguishing its specular UV reflectors from the
polished aluminum reflectors of Bigelow were deliberate
and definitive: “[n]owhere in Bigelow is anything regarding
a specular reflector disclosed—either expressly or inher-
ently.” J.A. 2527. “It is well settled . . . that it is the appli-
cant, not the examiner, who must give up or disclaim
subject matter that would otherwise fall within the scope
of the claims.” Innova/Pure Water, Inc. v. Safari Water
Filtration Sys., Inc., 381 F.3d 1111, 1124 (Fed. Cir. 2004).
Focusing on the applicant’s conduct, we hold that the ap-
plicant made a clear and unmistakable disclaimer during
prosecution.
C
Next, Puradigm argues that the applicant acquiesced
to the examiner’s position that Bigelow discloses specular
UV reflectors, thus negating any disclaimer made in dis-
tinguishing Bigelow. That argument, too, is unpersuasive.
Analyzing the prosecution history as a whole, we may
consider whether the applicant “retracted any of his state-
ments distinguishing [the prior art]” or whether he “acqui-
esced in the examiner’s comments.” Springs Window
Fashions LP v. Novo Indus., L.P., 323 F.3d 989, 995
(Fed. Cir. 2003). Here, the applicant did neither.
After stating that “[n]owhere in Bigelow is anything re-
garding a specular reflector disclosed—either expressly or
inherently,” the applicant never retracted this statement.
See J.A. 2527–2750. Nor did the applicant acquiesce to the
examiner’s position—that Bigelow’s polished aluminum
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PURADIGM , LLC v. DBG GROUP INVESTMENTS LLC 10
meets the claimed specular UV reflector—simply by pursu-
ing its original argument no further. Instead, the applicant
responded that it “neither agrees nor disagrees with such
statements and explicitly reserves the right to challenge
such statements in the future should the need arise.”
J.A. 2594. Thus, the applicant explicitly chose not to agree
with the examiner. In later rounds of prosecution, the ap-
plicant went on to distinguish other prior art and make fur-
ther amendments relating to the claimed reflectors but
never revisited this point. Such conduct cannot constitute
acquiescence.
Puradigm argues this case is like Malvern Panalytical
Inc. v. TA Instruments-Waters LLC, 85 F.4th 1365
(Fed. Cir. 2023), and Ecolab, 569 F.3d 1335. But those
cases are distinguishable. In the circumstances of Mal-
vern, “where an applicant abandon[ed] its unsuccessful ar-
gument” in the prosecution of an unrelated (but commonly
assigned) application and overcame the rejection on other
grounds, we concluded that “the prosecution history
lack[ed] the clarity necessary to establish prosecution dis-
claimer.” 85 F.4th at 1376. And in Ecolab, we held that
the prosecution history was not clear and unmistakable
enough to invoke disclaimer because a reasonable reader of
the prosecution history could conclude the applicant’s ini-
tial statements were in error, the examiner corrected them,
and the applicant later recognized the error. 569 F.3d at
1343. Unlike those cases, our review of the prosecution his-
tory as a whole in this case yields the conclusion that the
applicant clearly and unmistakably disclaimed Bigelow’s
polished aluminum reflectors from the scope of its claimed
specular UV reflectors. There is no indication in this rec-
ord that the applicant recognized its characterization of Bi-
gelow’s polished aluminum as not being specular UV
reflectors was somehow in error. The fact that prosecution
may have shifted to a different but related concept of the
claimed specular UV reflectors reflecting UV energy “di-
rectly to” the photo-catalytic coating of the first and second
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PURADIGM , LLC v. DBG GROUP INVESTMENTS LLC 11
targets does not blunt the impact of the applicant’s earlier
remarks. See Springs Window, 323 F.3d at 995.
II
Finally, Puradigm argues that the district court erred
by providing only a partial construction of “specular UV re-
flector” and declining to adopt Puradigm’s construction.
Puradigm is effectively disputing the scope of the dis-
claimer found by the district court, i.e., that “DBG’s unpol-
ished aluminum reflectors are also disclaimed from the
scope of ‘specular UV reflector.’” Puradigm, 2024 WL
3997489, at *10. The district court applied this scope in
making its summary judgment ruling. Id. We see no error
in the district court’s analysis, which was sufficient to re-
solve the dispute before it.
Puradigm acknowledged that “for summary judgment,
it was not disputed[] that the accused device has a reflector
made of unpolished aluminum.” Appellant’s Br. 7 (footnote
omitted). Because the applicant for the ’979 patent dis-
claimed Bigelow’s polished aluminum reflectors, as ex-
plained above, the only remaining question is whether as a
matter of law this disclaimer covers unpolished variants of
the same material—aluminum. We hold that it does.
The ’979 patent and prosecution history make clear
that the property of specular UV reflectors enabling them
to send UV energy “directly to” the photo-catalytic coating
of the first and second targets is that they produce mirror-
like reflection, as opposed to diffuse reflection “where an
incoming light ray is reflected into a broad range of direc-
tions.” ’979 patent col. 3 ll. 37–44. One way to achieve this
is “to ‘micro-polish or buff’ a selected material[’]s reflective
surface.” Id. at col. 3 ll. 27–30.
The undisputed evidence of record establishes that a
less polished or unpolished surface would produce more dif-
fuse reflection and less specular reflection than a polished
one. Even Puradigm’s expert acknowledges that a given
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PURADIGM , LLC v. DBG GROUP INVESTMENTS LLC 12
material’s surface roughness “can lead to scattering and
diffuse reflection of radiation.” J.A. 2913 (Milster declara-
tion). Puradigm cannot reasonably dispute that unpol-
ished aluminum (as in the accused products) is rougher
than polished aluminum (as in Bigelow). The rougher the
surface, the more diffuse (and less specular) reflection
would be produced. Thus, the applicant’s disclaimer of Bi-
gelow’s polished aluminum reflectors logically extends to
unpolished reflectors of the same material. In these cir-
cumstances, no reasonable juror could find the accused
products to be encompassed by the claims.
CONCLUSION
We have considered Puradigm’s remaining arguments
and find them unpersuasive. For the foregoing reasons, we
affirm.
AFFIRMED
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