Sigray, Inc. v. Carl Zeiss X-Ray Microscopy, Inc.

United States Court of Appeals
for the Federal Circuit
______________________
SIGRAY, INC.,
Appellant
v.
CARL ZEISS X-RAY MICROSCOPY, INC.,
Appellee
______________________
2023-2211
______________________
Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. IPR2022-
00218.
______________________
Decided: May 23, 2025
______________________
ALAN G RAYSON L AQUER, Knobbe, Martens, Olson &
Bear, LLP, Irvine, CA, argued for appellant. Also repre-
sented by CRAIG S. SUMMERS , J AMES YOUNGBLOOD.
K URT L OUIS G LITZENSTEIN, Fish & Richardson P.C., Bos-
ton, MA, argued for appellee. Also represented by RYAN
P ATRICK O'C ONNOR, J OHN C. P HILLIPS , San Diego, CA;
CHARLES N EVILLE REESE , J R., Atlanta, GA.
______________________
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SIGRAY , INC. v. CARL ZEISS X - RAY MICROSCOPY , INC. 2
Before D YK and P ROST , Circuit Judges, and G OLDBERG,
Chief District Judge.1
G OLDBERG, Chief District Judge.
Appellee Carl Zeiss X-Ray Microscopy, Inc. (“Zeiss”)
owns U.S. Patent No. 7,400,704 (the “’704 patent”), which
claims X-ray imaging systems that incorporate projection
magnification. Appellant Sigray, Inc. (“Sigray”) filed a pe-
tition with the Patent and Trademark Office requesting in-
ter partes review of all claims of that patent. The Board
granted Sigray’s petition, finding that it demonstrated a
reasonable likelihood that at least one of the challenged
claims was unpatentable. In its final written decision, the
Board declined to hold any of the asserted claims unpatent-
able. Sigray, Inc., v. Carl Zeiss X-Ray Microscopy, Inc.,
No. IPR2022-00218, 2023 WL 5065239 (P.T.A.B. May 22,
2023) (“Decision”). Sigray appeals the Board’s decision only
as to whether claims 1–6 were unpatentable based on the
prior art reference Jorgensen.2 Specifically, Sigray chal-
lenges the Board’s determination that claims 1, 3, and 4
were not anticipated by Jorgensen and that claims 1–6
would not have been obvious over Jorgensen, either in com-
bination with other references or under a single reference
theory. We reverse as to the lack of anticipation of claims
1, 3, and 4 and remand for the Board to determine if claims
2, 5, and 6 would have been obvious in light of this opinion.
1 Honorable Mitchell S. Goldberg, Chief Judge,
United States District Court for the Eastern District of
Pennsylvania, sitting by designation.
2 S. Jorgensen, et al., Three-Dimensional Imaging of
Vasculature and Parenchyma in Intact Rodent Organs
with X-ray Micro-CT, Am. J. Physiology (Sept. 1998)
(“Jorgensen”).
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SIGRAY , INC. v. CARL ZEISS X - RAY MICROSCOPY , INC. 3
BACKGROUND
X-ray technology has long been utilized to generate vis-
ual images of internal structures otherwise invisible to the
naked eye. The typical X-ray process entails: (1) an X-ray
source generating an X-ray beam, (2) that beam penetrat-
ing a sample, and (3) a detector receiving the transmitted
beam. The information received by the detector is used to
generate an image.
The patent at issue incorporates into this process a
mechanism known as projection magnification, which en-
larges the generated image. ’704 patent, col. 2 ll. 47–49.
Claim 1, of which all other disputed claims depend, recites:
An x ray imaging system, comprising:
a projection x ray stage including:
an x ray source generating a di-
verging x ray beam; and
a scintillator for converting the x
ray beam, after interacting with a
sample, into an optical signal;
an optical stage including:
a detector; and
a magnification lens for imaging
the optical signal of the scintillator
onto the detector;
wherein a magnification of the pro-
jection x ray stage is between 1 and
10 times and a magnification of the
optical stage is 5 or greater.
Id. at col. 9 l. 62–col. 10 l. 7 (emphasis added).
Projection magnification, also known as geometric
magnification, utilizes diverging rays that spread out as
they travel. The distance between the rays increases after
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SIGRAY , INC. v. CARL ZEISS X - RAY MICROSCOPY , INC. 4
interacting with the sample but before being received by
the detector. As a result, the generated image is larger than
the sample itself. The level of magnification depends on the
relative distances between the source, sample, and detec-
tor. Id. at col. 1 ll. 43–51. A larger distance between the
source and the sample or a smaller distance between the
sample and the detector will result in less magnification,
and vise-versa.3
STANDARD OF REVIEW
We review the Board’s legal conclusions de novo and its
factual findings for substantial evidence. ACCO Brands
Corp. v. Fellowes, Inc., 813 F.3d 1361, 1365 (Fed. Cir.
2016). Anticipation is a question of fact reviewed for sub-
stantial evidence, In re Rambus Inc., 694 F.3d 42, 46
(Fed. Cir. 2012), as is the question of whether a claim lim-
itation is inherent in a prior art reference. Monsanto Tech.
LLC v. E.I. DuPont de Nemours & Co., 878 F.3d 1336, 1342
(Fed. Cir. 2018) (citing Telemac Cellular Corp. v. Topp Tel-
ecom, Inc., 247 F.3d 1316, 1328 (Fed. Cir. 2001)). Substan-
tial evidence “means such relevant evidence as a
reasonable mind might accept as adequate to support a
conclusion.” In re Gartside, 203 F.3d 1305, 1312 (Fed. Cir.
2000) (quoting Consol. Edison Co. of New York v. N.L.R.B.,
305 U.S. 197, 229 (1938)).
“Claim construction is ultimately a question of law, de-
cided de novo on review, as are the intrinsic-evidence
3 This is expressed as M = (L s + Ld)/L s, where M is
the level of magnification, L s is the distance between the
source and the sample, and L d is the distance between the
sample and the detector. ’704 patent, col. 1 ll. 43–51. When
M = 1, the size of the sample is equal to the size of the gen-
erated image, i.e., there is no magnification. This formula
is applicable only if the rays are diverging, as completely
parallel rays result in no magnification.
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SIGRAY , INC. v. CARL ZEISS X - RAY MICROSCOPY , INC. 5
aspects of a claim-construction analysis.” Intel Corp. v.
Qualcomm Inc., 21 F.4th 801, 808 (Fed. Cir. 2021).
D ISCUSSION
Before the Board, Sigray asserted that claim 1 was an-
ticipated by Jorgensen. A claim is anticipated only when
every claim limitation is disclosed within a single refer-
ence. Biogen MA Inc. v. EMD Serono, Inc., 976 F.3d 1326,
1331–32 (Fed. Cir. 2020). “Moreover, a prior art reference
may anticipate without disclosing a feature of the claimed
invention if that missing characteristic is necessarily pre-
sent, or inherent, in the single anticipating reference.”
SmithKline Beecham Corp. v. Apotex Corp., 403 F.3d 1331,
1343 (Fed. Cir. 2005) (quoting Schering Corp. v. Geneva
Pharms., Inc., 339 F.3d 1373, 1377 (Fed. Cir. 2003)). A lim-
itation is inherently disclosed “when the reference discloses
prior art that must necessarily include the unstated limita-
tion.” Transclean Corp. v. Bridgewood Servs., Inc.,
290 F.3d 1364, 1373 (Fed. Cir. 2002). Inherent disclosure
does not require a person of ordinary skill to recognize the
presence of the limitation at the time the reference is gen-
erated. SmithKline, 403 F.3d at 1343. Any presence of the
limitation in the reference inherently discloses it for the
purposes of anticipation. See id. at 1345 (“Because the rec-
ord contains clear and convincing evidence that production
of PHC anhydrate in accordance with the ’196 patent in-
herently results in at least trace amounts of PHC hemihy-
drate, this court holds that the ’196 patent inherently
anticipates claim 1 of the ’723 patent under 35 U.S.C.
§ 102(b).”).
Jorgensen is a scientific paper that describes using an
X-ray beam to image rodent organs. It describes a system
that uses an X-ray source to generate an X-ray beam, which
then passes through a sample before being received by a
detector. J.A. 673. Jorgensen attempts to reduce concerns
related to projection magnification by providing a large dis-
tance between the sample and the source and a short
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SIGRAY , INC. v. CARL ZEISS X - RAY MICROSCOPY , INC. 6
distance between the sample and the detector. Id. Addi-
tionally, Jorgensen references a process known as collima-
tion, explaining that “[t]he collimated X-ray beam is
shielded by a lead-wrapped brass tube as the beam passes
from the source into the shielded cover of the scanner.” Id.
at 674.
There is no disagreement that Jorgensen explicitly dis-
closes all limitations of claim 1, except for the projection
magnification limitation, which, as set forth above, reads
“a magnification of the projection X ray stage . . . between
1 and 10 times.” ’704 patent, col. 10 ll. 5–6. The parties’ pri-
mary dispute is whether this limitation is inherently dis-
closed in Jorgensen.
The fact that projection magnification is the result of
diverging rays interacting with a sample is agreed upon. It
is also uncontested that Jorgensen’s source creates a di-
verging beam that passes through a collimator before
reaching the sample. Zeiss concedes that a beam that is di-
verging, even by an undetectable amount, will result in
some magnification4 but asserts that Jorgensen is not an-
ticipatory because its collimator eliminates divergence, re-
sulting in a parallel or non-diverging beam.
Sigray disagrees, arguing that Jorgensen’s collimator
cannot eliminate divergence but rather only reduces it.
Therefore, the question before the Board was whether
Jorgensen’s collimator eliminated X-ray divergence, thus
negating inherent disclosure.
The Board ultimately concluded that “viewing the rec-
ord as a whole, . . . [Sigray] has not shown persuasively
that Jorgensen inherently discloses projection magnifica-
tion within the claimed range.” Decision, 2023 WL
5065239, at *17. In finding no inherent disclosure, the
4 See Oral Arg. at 11:22–12:03, https://www.cafc.usc-
ourts.gov/home/oral-argument/listen-to-oral-arguments/.
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SIGRAY , INC. v. CARL ZEISS X - RAY MICROSCOPY , INC. 7
Board cited “a vigorous dispute about whether Jorgensen
teaches a diverging X-ray beam.” Id. Sigray argues that
these findings are flawed as they depend on an incorrect
understanding of the claimed range. Specifically, Sigray
asserts that the Board implicitly and incorrectly construed
the limitation “between 1 and 10” to exclude unspecified,
small divergence resulting in projection magnifications
only slightly greater than 1. Appellant’s Br. 1–2. According
to Sigray, this was error because the claim contains no such
exclusion. Zeiss disputes that any claim construction oc-
curred.
While the Board stated that it was not engaging in
claim construction, those statements are “not dispositive as
to whether claim construction occurred.” Google LLC v.
EcoFactor, Inc., 92 F.4th 1049, 1056 (Fed. Cir. 2024). In-
stead, in determining whether the Board construed a
claim, we look at the outcome of the Board’s analysis and
its reasoning. See id. at 1055. If the outcome of the Board’s
analysis establishes the scope and meaning of the claim,
then the Board has implicitly construed the claim. Id.
Here the Board’s analysis demonstrates that it con-
strued the disputed claim limitation. Most notably, the
Board stated that Sigray “fail[ed] to show that the . . . X-
ray beam in Jorgensen diverges enough to result in projec-
tion magnification ‘between 1 and 10 times’ . . . .” Decision,
2023 WL 5065239, at *11 (emphasis added). The Board’s
use of the word “enough” reflects that it considered a cer-
tain level of divergence as outside the claim. Narrowing the
claim scope in this way is in fact claim construction.
Zeiss posits that the Board’s single use of the word
“enough” is taken out of context and that the Board actu-
ally found that Jorgensen does not disclose a diverging
beam. We disagree. An examination of the Board’s analysis
demonstrates that (1) it applied the word “enough” in
reaching its conclusion and (2) that the evidence relied on
by the Board supports a finding of some divergence.
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SIGRAY , INC. v. CARL ZEISS X - RAY MICROSCOPY , INC. 8
First, the Board describes the term “collimated X-ray
beam” in a way that suggests that collimation reduces
without eliminating divergence. Id. at *10–12. The Board
relied on U.S. Patent No. 4,891,829 (the “’829 patent”) for
the assertion that “[d]ifferent collimation techniques can
be used to achieve [the required] degree of parallelism” and
reasoned that the ’829 patent “thus confirms that collima-
tion is [a] technique for minimizing beam divergence so as
to provide a nearly parallel X-ray beam.” Id. at *10 (first
and second alterations in original) (emphases added).
The Board further relied on the testimony of Zeiss’s ex-
pert Dr. Gonzalo Acre, who stated that a “collimated X-ray
beam is a beam where . . . no meaningful divergence is pre-
sent,” and “the X-rays that reach Jorgensen’s sample are
essentially parallel (i.e., not diverging) and there is no pro-
jection stage magnification.” Id. at *10–11 (emphases
added) (quoting J.A. 2779–81).
The above two examples discuss reduction in diver-
gence but expressly contemplate the continued existence of
some amount of divergence. The fact that the Board relied
on this evidence to find no inherent disclosure demon-
strates that the Board narrowed the disputed limitation to
exclude magnification generated by small amounts of di-
vergence, that would result in magnification “between 1
and 10 times.”
Second, the Board considered Jorgensen’s prefatory
clause, which identifies an “X-ray focal spot that subtends
≤0.8 mrad at the [detector].” Id. at *12. The Board relied on
Zeiss’s expert Dr. Julie Bentley’s explanation that 0.8
mrad is “a very small angle and is small enough to be con-
sidered [a] parallel source at infinity.” Id. at *11 (alteration
in original) (quoting J.A. 2207). Angles are created from in-
tersecting lines, and parallel lines do not intersect. The
mere presence of an angle demonstrates divergence, and
the Board’s consideration of degree of divergence again
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SIGRAY , INC. v. CARL ZEISS X - RAY MICROSCOPY , INC. 9
demonstrates its belief that small amounts of divergence,
and therefore magnification, are outside the claim.
Third, the Board relied on the testimony of Dr. Bentley,
who stated:
Jorgensen explains that when magnification of the
lens is set to 2x, the [sample] size is doubled by the
lens (such that a 12 μm on a side square at the sam-
ple corresponds to a 24 μm on a side pixel at the
detector). That can be true only if there is no addi-
tional magnification in the projection stage. . . .
[E]ven if the projection stage magnification were
only 1.1x, then a 24 μm pixel at the detector would
correspond to a 10.9 μm pixel referenced to the
sample, not 12 μm, as stated by Jorgensen.
Id. at *15 (emphasis in original) (internal quotation marks
omitted) (quoting J.A. 1181). However, had Dr. Bentley
performed the same calculation using a 1.001x magnifica-
tion and the same rounding principles, she would have
reached “12 μm,” which is what is represented in Jorgen-
sen. In other words, Dr. Bentley’s testimony highlights
that Jorgensen’s passage is too imprecise to capture very
small magnification and is relevant only if the Board con-
strued the claim to exclude small levels of magnification
that were nonetheless between 1 and 10. While this evi-
dence is unhelpful in determining if magnification is inher-
ently present, it reflects that the Board engaged in claim
construction.
Fourth, the Board considered Jorgensen’s explanation
that “[t]he geometry and intensity distribution of the X-ray
focal spot are of concern if the X-ray beam geometry is used
to achieve magnification, but in our system the long X-ray
focal spot-to-[sample] distance and the close proximity of
the [sample] to the [detector] greatly reduce this concern.”
Id. at *5 (quoting J.A. 673). The Board states that “greatly
reduc[ing] [the] concern” related to magnification shows
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SIGRAY , INC. v. CARL ZEISS X - RAY MICROSCOPY , INC. 10
that Jorgensen “does not use the X-ray beam geometry to
achieve magnification.” Id. at *10 (emphasis in original).
However, Jorgensen’s aspirational statements of pur-
pose that it is not attempting to achieve magnification does
not address whether magnification is inherently present.
See SmithKline, 403 F.3d at 1344 (finding inherent disclo-
sure of a compound that was unknown when the prior art
reference was created). “Reduce” does not mean eliminate.
As stated in the specification of the ’704 patent, elimina-
tion of magnification can only be achieved if the distance
between the sample and the detector is zero.5 The fact that
the Board was satisfied with Jorgensen’s reduction further
demonstrates that it considered small amounts of magnifi-
cation as not between 1 and 10 as required by the claim.
Additionally, the spacing of the components affect mag-
nification only in the presence of a diverging beam. Thus,
Jorgensen’s attempt to reduce magnification in this way in-
dicates the presence of a diverging beam.
Finally, the Board continuously relied on Zeiss’s ex-
perts for the assertion that Jorgensen did not contain a di-
verging beam. Decision, 2023 WL 5065239, at *17.
However, Dr. Bentley and Dr. Acre continuously stated
that collimation of the type found in Jorgensen reduces,
without eliminating, divergence. The Board cited to
Dr. Bentley’s testimony that the source was made to look
“like it’s far enough [a]way that those rays are essentially
parallel,” and Dr. Acre’s testimony that a “collimated X-ray
beam is a beam where the X-rays have been made to be
parallel such that no meaningful divergence is present.” Id.
at *10–13 (emphasis added) (citations omitted). These
statements, and others like them, support a finding that
some divergence was present and is consistent with the
5 M = 1 only when Ld = 0.
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SIGRAY , INC. v. CARL ZEISS X - RAY MICROSCOPY , INC. 11
Board’s analysis only under an alternative claim construc-
tion.
Viewing the Board’s reasoning, we conclude it con-
strued “between 1 and 10” to exclude small amounts of
magnification. This was error. At all times, the language of
the claims govern their scope and meaning, and unless the
intrinsic evidence compels a contrary conclusion, the claim
language carries the meaning accorded those words in the
usage of skilled artisans at the time of invention.
SmithKline, 403 F.3d at 1339. In SmithKline, this court
concluded that a claim to PHC hemihydrate was inherently
anticipated because “producing PHC anydrate according to
the [prior art] inevitably results in the production of at
least trace amounts of . . . PHC hemihydrate.” Id. at 1344.
We found that the district court erred in requiring a higher
standard of proof because it was “sufficient to show that
the natural result flowing from the operation as taught [in
the prior art] would result in” the claimed invention. Id.
at 1343 (alteration in original) (quoting In re Oelrich,
666 F.2d 578, 581 (CCPA 1981)). Here, it is undisputed
that Jorgenson’s X-ray beams are not completely parallel
and naturally must result in some magnification. That
miniscule amount of magnification disclosed by the prior
art definitionally achieves a magnification within the
claimed range of 1 to 10. This court “repeatedly and con-
sistently has recognized that courts may not redraft claims,
whether to make them operable or to sustain their valid-
ity.” Chef Am., Inc. v. Lamb-Weston, Inc., 358 F.3d 1371,
1374 (Fed. Cir. 2004). The plain meaning of “between 1 and
10” includes tiny, even undetectable, magnification, and
Zeiss has pointed to nothing compelling a contrary conclu-
sion.
As the Board applied an incorrect claim construction,
it never addressed anticipation under the correct construc-
tion. Reversal, rather than remand, is appropriate if “[o]n
the evidence and arguments presented to the Board, there
is only one possible evidence-supported finding: [that] the
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SIGRAY , INC. v. CARL ZEISS X - RAY MICROSCOPY , INC. 12
Board’s [determination] . . . when the correct construction
is employed, is not supported by substantial evidence.” Ow-
ens Corning v. Fast Felt Corp., 873 F.3d 896, 901–02
(Fed. Cir. 2017) (reversing, rather than remanding, when
“only one answer is supported by substantial evidence”).
As explained above, the evidence relied on by the Board
compels a singular conclusion—that Jorgensen inherently
contains projection magnification. Zeiss has recognized
“that absolute, theoretical parallelism cannot be achieved
as a practical matter,” J.A. 2465 n.3, and “if there is diver-
gence of the X-ray beams . . . at the point they pass through
the [sample], then . . . the consequence of that is that there
would be some geometric magnification in the projection.”
Oral Arg. at 11:45–11:56. The only evidence-supported con-
clusion is that Jorgensen contains a beam diverging at the
sample, which necessarily produces projection magnifica-
tion over 1. As such, claim 1 is anticipated by Jorgensen.
Finding that claim 1 is anticipated, we now turn to the
remaining disputed claims, all of which are dependent on
claim 1. “When a dependent claim and the independent
claim it incorporates are not separately argued, precedent
guides that absent some effort at distinction, the claims
rise or fall together.” Soverain Software LLC v. Newegg
Inc., 728 F.3d 1332, 1335 (Fed. Cir. 2013). Before the
Board, Sigray asserted that claims 3 and 4 were antici-
pated by Jorgensen, and Zeiss did not separately argue
these claims to the Board. We cannot discern for ourselves
any independent basis for why these claims, which recite
narrower versions of limitations found in claim 1, are not
unpatentable.
Sigray never asserted that claims 2, 5, and 6 were an-
ticipated and instead argued unpatentability under vari-
ous obviousness theories. J.A. 108. Even though Sigray
asserted that these claims would have been obvious based
on Jorgensen as a single reference, “it does not follow that
every technically anticipated invention would also have
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SIGRAY , INC. v. CARL ZEISS X - RAY MICROSCOPY , INC. 13
been obvious.” Cohesive Techs., Inc. v. Waters Corp.,
543 F.3d 1351, 1364 (Fed. Cir. 2008) (quoting In re Fra-
calossi, 681 F.2d 792, 796 (CCPA 1982) (Miller, J., concur-
ring)). We therefore remand to the Board to consider
whether claims 2, 5, and 6 would have been obvious.
CONCLUSION
The Board’s decision regarding claims 1, 3, and 4, is
reversed. The Board’s decision as to claims 2, 5, and 6, is
vacated. The matter is remanded for further proceedings
consistent with this opinion.
REVERSED-IN-PART, VACATED-IN-PART, AND
REMANDED
COSTS
Costs to Appellant.
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