Court Opinion

ID: 3187207
Source: CourtListenerOpinion
Date Created: 2016-03-21 15:05:22.104523+00
Date Added: 2024-06-11T14:35:47.499910
License: Public Domain

United States Court of Appeals
      for the Federal Circuit
                ______________________

                 IN RE: CREE, INC.,
                       Appellant
                ______________________

                      2015-1365
                ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. 90/010,940.
                  ______________________

               Decided: March 21, 2016
               ______________________

    WILLIAM F. LEE, Wilmer Cutler Pickering Hale and
Dorr LLP, Boston, MA, argued for appellant. Also repre-
sented by SYDENHAM B. ALEXANDER, III, PETER M.
DICHIARA, MARK CHRISTOPHER FLEMING, CYNTHIA D.
VREELAND; BRITTANY BLUEITT AMADI, HEATHER M.
PETRUZZI, Washington, DC.

    PHILIP J. WARRICK, Office of the Solicitor, United
States Patent and Trademark Office, Alexandria, VA,
argued for appellee Michelle K. Lee. Also represented by
THOMAS W. KRAUSE, STACY BETH MARGOLIES, ROBERT J.
MCMANUS.
                 ______________________

 Before CHEN, CLEVENGER, and BRYSON, Circuit Judges.
BRYSON, Circuit Judge.
2                                           IN RE: CREE, INC.

    This is an appeal from a decision of the Patent Trial
and Appeal Board in an ex parte reexamination proceed-
ing. The Board held various claims of a patent owned by
Cree, Inc., to be unpatentable as obvious. We affirm.
                             I
    The patent in suit, Cree’s U.S. Patent No. 6,600,175
(“the ’175 patent”), filed in 1996, is entitled “Solid State
White Light Emitter and Display Using Same.” The
claims at issue in this appeal are directed to the produc-
tion of white light through the “down-conversion” of blue
light from light-emitting diodes (“LEDs”).            Down-
conversion is the process in which high-energy (shorter
wavelength) light is absorbed by a material and then re-
emitted as lower energy (longer wavelength) light. By
choosing the particular absorbing material, light at a
desired wavelength (and thus a desired color) can be
produced.
    The examiner rejected six claims added during reex-
amination of the ’175 patent as obvious under multiple
combinations of prior art references, including the combi-
nation of U.S. Patent No. 3,691,482 (“Pinnow”), U.S.
Patent No. 3,819,974 (“Stevenson”), and U.S. Patent No.
5,578,839 (“Nakamura”). The Board upheld the rejection
based on that combination of references, among others.
    Claim 118, added during reexamination of the ’175
patent, is representative of the six rejected claims. It
recites:
    A light-emission device, comprising a single-die,
    two-lead gallium nitride based semiconductor blue
    light-emitting diode emitting radiation; and a re-
    cipient down-converting luminophoric medium for
    down-converting the radiation emitted by the
    light-emitting diode, to a polychromatic white
    light, wherein the luminophoric medium is dis-
    persed in a polymer that is on or about the single-
IN RE: CREE, INC.                                         3

    die, two lead gallium nitride based semiconductor
    blue light-emitting diode.
    The patent defines the term “luminophoric medium”
to mean “a material which in response to radiation emit-
ted by the solid state device emits light in the white
visible light spectrum by fluorescence and/or phosphores-
cence.” In the context of lamps and other lighting appli-
cations, luminophoric materials are called phosphors;
such phosphors emit light through either fluorescence or
phosphorescence. 1 Fluorescence and phosphorescence are
examples of down-conversion. In both cases, the essential
principle is that light of short wavelength, such as blue or
ultraviolet light, is absorbed by a phosphor and later re-
emitted in the form of light with a longer wavelength.
Different phosphors emit light of different colors, and
phosphors can be combined to produce a range of colors.
    Down-conversion has a long history as a source of
light of various colors, including white light. For example,
fluorescent lamps create white light by down-converting
the ultraviolet light emitted by excited mercury gas.
Fluorescent lamps are well known in the art and have
been commercially available since the 1930s.

    1   In both phosphorescence and fluorescence, the
luminescent material absorbs a photon that excites an
electron. In fluorescence, the electron quickly (on the
order of 10-9 seconds) returns to the ground state and
emits a photon having a wavelength equal to or longer
than that of the absorbed photon. Peter Pringsheim,
Fluorescence and Phosphorescence 2-5 (1949). In phos-
phorescence the process is much slower, and the light
emission can occur long after absorption. That property
accounts for glowing wristwatch hands and glow-in-the-
dark toys that can emit light in a dark room.
4                                          IN RE: CREE, INC.

    The ’175 patent recites the use of down-conversion to
create white light with an LED. In one embodiment
described in the ’175 patent, a blue LED commercially
available from Nichia Chemical Industries, Ltd., is used
with three commercially available phosphors—a blue
phosphor (Lumogen® F Violet 570), a green-yellow phos-
phor (Lumogen® F Yellow 083), and a red phosphor
(Lumogen® F Red 300). The combination of those colors
results in the production of light that is perceived as
white.
    The Pinnow patent, published in 1972, discloses a
display system that creates black and white images using
a combination of a blue laser and appropriate phosphors.
It also provides a detailed disclosure of the necessary
conditions to create white light through the process of
down-conversion.
    In particular, Pinnow teaches that a blue argon-ion
laser can produce white light by down-conversion of short
wavelength laser light to combinations of longer wave-
length light emitted by various phosphors. Pinnow ex-
plains that “a necessary condition for achieving a true
white is that the illuminating laser beam have a wave-
length of approximately 4,950 Å or shorter,” which is in
the blue to violet range of the visible spectrum.
     The Stevenson patent, published in 1974, discloses a
type of gallium nitride LED. Stevenson’s LED emits light
in the violet region of the spectrum and “may be converted
to lower frequencies (lower energy) with good conversion
efficiency using organic and inorganic phosphors.” Ste-
venson notes that with the “use of different phosphors, all
the primary colors may be developed from this same basic
device.”
    Finally, the Nakamura patent, which was published
in Japan in 1993, discloses a gallium nitride LED that
emits blue light. The Nakamura LED was much brighter
than other similar LEDs previously developed, and it was
IN RE: CREE, INC.                                         5

widely recognized as a major breakthrough, earning Dr.
Nakamura the 2014 Nobel Prize in Physics.
     Based on those references, the examiner found that
“[i]t would have been obvious to one of ordinary skill in
the art, at the time of the invention to substitute Steven-
son’s GaN-based LED with either the known UV light
emitting or blue light emitting GaN-based LED disclosed
in Nakamura.” The examiner further found that the
combination was a “simple substitution of one known
element (Nakamura’s GaN-based LED) for another
known element (Stevenson’s GaN-based LED) to obtain
predictable results.” The examiner explained that the
reason to combine the references was the “advantage or
expected beneficial result” that would result from replac-
ing Stevenson’s LED with the more powerful Nakamura
LED. The examiner concluded that, because Nakamura’s
LED “would provide more photons to be down-converted
by the phosphors and thereby provide brighter overall
light emission from the device,” the advantage of brighter
emission by the phosphors would be readily apparent to a
person of ordinary skill in the art.
    The Board upheld the examiner’s rejection in view of
the combination of Pinnow, Stevenson, and Nakamura.
The Board agreed with the examiner’s reasoning, incorpo-
rating 109 pages of the examiner’s answer into its own
opinion. 2 In summarizing the grounds for its decision, the
Board stated:

    2   Cree suggests that it was improper under the
Administrative Procedure Act for the Board to incorporate
substantial portions of the Examiner’s Answer into its
opinion. There is no force to that argument. It is com-
monplace in administrative law for a reviewing body
within an agency to adopt a fact-finding body’s findings.
On judicial review, the adopted material is treated as if it
6                                          IN RE: CREE, INC.

    (1) Stevenson and Nakamura teach a two-lead,
    GaN-based blue LED on a single die, (2) Steven-
    son and Pinnow teach a “down-conversion” via
    phosphors from LED light, including phosphors
    dispersed in a polymer located “about” the LED
    (Ans. 117-121) and, given the presumed
    knowledge by an artisan of ordinary skill regard-
    ing the relevant prior art at the time of Appel-
    lant’s invention, (3) the combined teachings of
    Stevenson, Pinnow, and Nakamura would have

were part of the reviewing body’s opinion. See, e.g., DHL
Express, Inc. v. NLRB, Nos. 12-1072, -1143, 2016 WL
278075, at *8 (D.C. Cir. Jan. 21, 2016); Sanchez-Robles v.
Lynch, 808 F.3d 688, 692 (6th Cir. 2015); Mike-Sell’s
Potato Chip Co. v. NLRB, 807 F.3d 318, 321 (D.C. Cir.
2015).
    This court does the same in the case of Board opinions
adopting patent examiners’ findings. See In re Brana, 51
F.3d 1560, 1564 n.13 (Fed. Cir. 1995) (“The Board’s deci-
sion did not expressly make any independent factual
determinations or legal conclusions. Rather, the Board
stated that it ‘agree[d] with the examiner’s well reasoned,
well stated and fully supported by citation of relevant
precedent position in every particular, and any further
comment which we might add would be redundant.’
Therefore, reference in this opinion to Board findings are
actually arguments made by the examiner which have
been expressly adopted by the Board.”) (internal citations
omitted).
    Contrary to Cree’s suggestion, this court in In re Lee,
277 F.3d 1338 (Fed. Cir. 2002), did not vacate the Board’s
decision on the ground that the Board adopted some
portions of the examiner’s answer as its own opinion.
Instead, we vacated the Board’s decision because “neither
the examiner nor the Board adequately supported” the
rejection.
IN RE: CREE, INC.                                         7

    suggested to an artisan of ordinary skill to use a
    blue LED on a single die to create white light via
    “down-conversion” because Nakamura’s blue LED
    is more powerful than Stevenson’s older, less-
    efficient LED in terms of power and brightness
    and, as such, is more suitable with a “down-
    conversion” process to produce white light.
    In the Board’s view the invention was “nothing more
than a new application of a high-power, high-brightness
blue LED developed by Dr. Nakamura in late 1993.” The
Board found that the new application was predictable in
view of the state of the art in LEDs, the market demand
for white light devices, the finite number of identified
means to convert light from LEDs into white light, and
the advantages of using the down-conversion approach.
                            II
                            A
    On appeal, Cree first argues that the Board erred by
assuming that it was known in the prior art to make
white light from a monochromatic LED through down-
conversion. In Cree’s view, “[t]he Board ruled that it was
obvious to use down-conversion to create white light from
LEDs because it was (according to the Board) not merely
obvious, but actually already known.” Cree bases this
argument on a passage from the Board’s opinion in which
the Board stated the following:
    Appellant’s experts, Drs. Stringfellow, Redwing,
    and Wetzel, acknowledge: (1) Stevenson’s seminal
    work on a violet/blue LED in early 1974, and (2)
    at the time of Appellant’s invention in early 1996,
    there were two known approaches to produce
    white light from LEDs. One was a direct-emission
    “triplet” approach in which individual LEDs that
    emit three primary colors—red, green, and blue
    (RGB)—are packaged together and then all the
8                                            IN RE: CREE, INC.

    primary (RGB) colors are mixed together to form
    white light. The other was a “down-conversion”
    approach in which a phosphor material is used to
    convert monochromatic light from a blue or ultra-
    violet (UV) LED to create white light, much in the
    same way a fluorescent light bulb works.
    Cree infers that the Board’s use of the word “known”
in that passage indicates that the Board erroneously
concluded that a single reference disclosed down-
conversion from blue LED light to white light. We do not
read the Board’s use of the term “known” in that fashion.
    The Board’s opinion makes clear that the Board fo-
cused on the general disclosure of the process of down-
conversion, rather than any disclosure of down-conversion
limited to a particular source, i.e., an LED. The Board
explained that Pinnow discloses “a ‘down-conversion’
approach to create white light,” and that nothing in
Pinnow suggests that the particular source of primary
radiation is important to the down-conversion process.
    The examiner noted that Pinnow discusses down-
conversion generally, not the specific down-conversion of
blue LED light to white light. The examiner character-
ized the source of the primary radiation as unimportant
“because it is the wavelength of the source that matters
not the source itself.” In the portion of his answer that
the Board adopted, the examiner stated that a person of
ordinary skill in the art “is not going to fail to appreciate
the other teachings in Pinnow simply because a laser is
used as the primary light source, because the phosphors
cannot tell from what light source a wavelength of light
comes. Rather, they can only absorb or not absorb a given
wavelength.” The examiner also stated that “it does not
matter that Pinnow uses a laser, it only enhances the
point that a [person having ordinary skill in the art] is
aware of a variety of UV to blue radiation sources that are
capable of being used to produce light of various colors,
IN RE: CREE, INC.                                           9

including white, by down-converting the primary radia-
tion to longer-wavelength visible light using a mixture of
phosphors in a single medium.”
    In context, it is clear that the Board was not using the
word “known” to mean “disclosed in a single reference.”
Instead, the Board’s statement that down-conversion was
a known approach for creating white light from an LED is
best understood to mean that persons of skill in the art
were aware that down-conversion could be used to make
white light out of blue light, regardless of the source of the
light.
    The Board found that Pinnow teaches a down-
conversion process for creating white light that would
work with blue light of any source, including the blue
LEDs disclosed in Nakamura. That was an entirely
reasonable conclusion to draw from Pinnow. Therefore
the Board was correct when it said that it was “known” to
create white light from LEDs using down-conversion, as
Pinnow teaches a down-conversion process that was
understood to be equally applicable when used with an
LED light source as with the laser source specifically used
in Pinnow.
                              B
     Cree next argues that the Board reached its conclu-
sion that down-conversion was “known” by misreading the
declarations of Cree’s experts, Drs. Stringfellow, Redwing,
and Wetzel. We agree with the Board that Cree’s experts
testified that down-conversion from blue LED to white
light was a known, but disfavored, option prior to the
availability of high intensity blue LEDs such as Nakamu-
ra’s. Dr. Wetzel stated that “[d]own conversion of LED
light had been considered, but was discredited due to the
loss of energy and light brightness during the down-
conversion process.” He then went on to explain why
persons in the art would prefer to generate white light by
mixing the output of three primary colored LEDs in a
10                                          IN RE: CREE, INC.

triplet format. In saying that down-conversion was a
discredited solution to the problem of generating white
light from LEDs, Dr. Wetzel in effect acknowledged that
down-conversion of LED light was at least known to those
in the art. Thus, Dr. Wetzel’s testimony cuts against
Cree’s contention that generating white light from blue
LEDs was unknown.
    Dr. Redwing stated in her declaration that “down
conversion of LED light was known and had been used in
very select and rare occasions.” She added, however, that
down-conversion would not be used as a practical source
of white light, because white light applications would
have “required a significant amount of power and bright-
ness,” and “[l]ow illumination, as might be the case for an
indicator light or a calculator, would clearly be insuffi-
cient for white light in these applications.”
    Dr. Redwing’s statement addressed the question
whether, before the Nakamura LED, a person of skill in
the art would reject the down-conversion approach for
practical applications. As in the case of Dr. Wetzel,
however, her discussion of the competing technologies
clearly reveals that down-conversion was a known method
of creating white light prior to the ’175 patent. We there-
fore reject Cree’s suggestion that it was error for the
Board to cite Dr. Redwing’s testimony as support for its
finding that down-conversion to create white light from
LEDs was a known option prior to the ’175 patent.
    Finally, Dr. Stringfellow stated that at the time of the
’175 patent, “the industry was focused on LEDs that
directly emitted the color of interest and there was no
focus on the use of down-conversion because (a) it would
waste energy; (b) it was no longer needed to create prima-
ry colors; and (c) it entailed increased cost and complexi-
ty.” Again, his testimony simply establishes that the use
of down-conversion was not a preferred option for practi-
cal reasons. It does not show that down-conversion from
IN RE: CREE, INC.                                       11

LEDs was unknown or could not have practical applica-
tions if a sufficiently powerful LED were available (such
as the one invented by Nakamura). Because it was rea-
sonable for the Board to draw the conclusion from Dr.
Stringfellow’s testimony that down-conversion was a
known solution for generating white light from a blue
LED, the Board’s decision is supported by substantial
evidence. See In re Jolley, 308 F.3d 1317, 1329 (Fed. Cir.
2002) (“[W]here two different, inconsistent conclusions
may reasonably be drawn from the evidence in record, an
agency’s decision to favor one conclusion over the other is
the epitome of a decision that must be sustained upon
review for substantial evidence.”).
                            C
    Cree next takes issue with the Board’s analysis of the
motivation to combine. In particular, Cree argues that
“neither the Examiner nor the Board articulated any
rational motivation for why a skilled artisan would have
combined the teachings of Pinnow—which discloses the
projection of a large, high-powered, gas laser beam
through a modulator and a deflector and onto a phosphor
screen to display a white image—with the teachings of
Stevenson and Nakamura, which disclose violet and blue
LEDs.”
    Contrary to Cree’s contention, the Board provided a
sufficient, non-hindsight reason to combine the refer-
ences. The Board found that a person of ordinary skill in
the art would realize that Nakamura (a brighter LED)
would be an upgrade over the LED of Stevenson for use
with down-conversion and that the Nakamura LED would
therefore be suitable to produce white light based on the
teachings of Pinnow. The availability of the high-powered
Nakamura LED thus provided the motivation to combine
Stevenson’s use of LEDs to create primary colors with
Pinnow’s use of a short-wavelength light source to create
white light.
12                                          IN RE: CREE, INC.

    Cree’s quarrels with the Board’s analysis of the moti-
vation to combine are without merit. Cree argues that
because a laser generates more output power than an
LED, a person of ordinary skill would fail to appreciate
that Pinnow’s teachings on down-conversion would be
applicable to LEDs as well. However, the examiner
pointed to ample evidence that Pinnow’s teachings are
applicable to LEDs. In a portion of the examiner’s answer
adopted by the Board, the examiner explained that “the
phosphors’ ability to convert the UV-to-blue light is predi-
cated only on whether or not it can absorb a given wave-
length of light, not on which kind of light source a
particular wavelength of light is emitted, laser, LED, or
otherwise, as a [person of ordinary skill in the art] would
readily appreciate.” In other words, a phosphor does not
care how an incident photon of light at a particular wave-
length was generated.
     Cree also argues that color mixing and phosphor se-
lection are more difficult when using a source with a
broader emission spectrum, such as an LED, than one
with a narrower emission spectrum, such as a laser. The
examiner (in a portion of his answer adopted by the
Board) also addressed that issue: He stated that “the
issue of phosphor selection for UV-to-blue radiation was
successfully addressed in the 1930’s. While the exact
same phosphor mixture as used in fluorescent bulbs
might not be used with a GaN-based LED of Stevenson or
Nakamura, it certainly is factual evidence that those of
skill in the art have sufficient understanding of the scien-
tific and engineering principles to choose phosphors for a
broadband, UV-to-blue primary radiation source.” The
examiner and the Board thus based the rejection on
IN RE: CREE, INC.                                        13

sufficient evidence that a person of ordinary skill in the
art would have had a reason to combine the references. 3
                            III
    Cree’s final argument is that the Board improperly re-
jected Cree’s proffered secondary evidence of non-
obviousness. Cree points to three categories of secondary
evidence that, according to Cree, the Board improperly
discounted: evidence of industry praise; evidence of licens-
ing; and evidence of the commercial success of white LED

    3   Cree argues that the Board’s rejection was based
on “impermissible hindsight.” That argument, however,
is essentially a repackaging of the argument that there
was insufficient evidence of a motivation to combine the
references. It is fully answered by the Board’s observa-
tion that “the weight of the evidence shows that the
proffered combination is merely a predictable use of prior
art elements according to their established functions.”
     Cree also asserts that the Board improperly shifted
the burden to Cree to show that the claims at issue would
not have been obvious. That argument, too, lacks merit.
The Board stated that the examiner had provided “a
reason showing motivation by a person of ordinary skill in
the art to achieve the claimed subject matter.” Immedi-
ately thereafter, in the passage quoted by Cree, the Board
stated that Cree “has not demonstrated why that reason
is erroneous or why a person of ordinary skill in the art
would not have reached the conclusions reached by the
Examiner” (emphasis in original). In context, it is clear
that the sentence quoted by Cree simply states that Cree
failed to show why the examiner’s finding was incorrect.
In short, the Board held that the examiner carried his
burden on the issue of obviousness, and Cree failed to
offer any convincing reason to find otherwise. That is not
burden-shifting. See Belden, Inc. v. Berk-Tek LLC, 610 F.
App’x 997, 1004-05 (Fed. Cir. 2015).
14                                          IN RE: CREE, INC.

products. The Board analyzed each of the claimed sec-
ondary considerations and concluded that the evidence of
secondary considerations “does not outweigh the strong
evidence of obviousness.”
                             A
    Cree first points to two press releases from the
Fraunhoffer Institute and contends that those press
releases support the inference of non-obviousness. The
press releases describe the down-conversion of blue LED
light to produce white light as a “breakthrough” and an
“innovative idea.” The Board, however, found the press
releases unpersuasive as secondary evidence, because the
praise was directed to the Fraunhoffer Institute’s own
work, not the work of the inventors of the ’175 patent.
     Cree faults the Board for discounting that evidence.
In Cree’s view, even though the press releases were
directed to the work of others, the praise for the concept
still had the requisite nexus to the claimed invention.
    We agree with the Board’s treatment of this evidence.
While “praise in the industry for a patented invention,
and specifically praise from a competitor tends to ‘indicate
that the invention was not obvious,’” self-serving state-
ments from researchers about their own work do not have
the same reliability. Power-One v. Artesyn Techs., Inc.,
599 F.3d 1343, 1352 (Fed. Cir. 2010) (quoting Allen Ar-
chery, Inc. v. Browning Mfg. Co., 819 F.2d 1087, 1092
(Fed. Cir. 1987)). The Board thus permissibly concluded
that the press releases were unpersuasive and, if any-
thing, showed that down-conversion was the logical next
step after the development of the Nakamura LED.
                             B
    Cree next points to evidence of licensing. During the
reexamination proceedings, Cree put forward declaration
testimony and press releases describing certain licensing
transactions. The Board found the evidence of licensing
IN RE: CREE, INC.                                            15

unpersuasive for failing to show a sufficient nexus to the
’175 patent.
    Our cases “specifically require affirmative evidence of
nexus where the evidence of commercial success present-
ed is a license, because it is often ‘cheaper to take licenses
than to defend infringement suits.’” Iron Grip Barbell Co.
v. USA Sports, Inc., 392 F.3d 1317, 1324 (Fed. Cir. 2004)
(quoting EWP Corp. v. Reliance Universal Inc., 755 F.2d
898, 908 (Fed. Cir. 1985)). When the specific licenses are
not in the record, it is difficult for the court to determine if
“the licensing program was successful either because of
the merits of the claimed invention or because they were
entered into as business decisions to avoid litigation,
because of prior business relationships, or for other eco-
nomic reasons.” In re Antor Media Corp., 689 F.3d 1282,
1294 (Fed. Cir. 2012). That is the situation here. Cree
has provided press releases evidencing that it has entered
into licensing transactions, but has not shown that the
licenses were based on the merits of the ’175 patent.
    Additionally, the press releases indicate that some of
the licenses were broad cross-licenses (such as the licens-
es to Nichia, Toyoda Gosei, Osram, and Phillips) or were
intended to resolve litigation (such as the license to
Nichia). Some of the press releases on which Cree relies
define the scope of the licensing transactions as “broad
and substantial,” “comprehensive [and] worldwide,” and
“cover[ing] patents from both parties in the fields of blue
LED chip technology, white LEDs and phosphors (includ-
ing remote phosphors), control systems, LED luminaries
and lamps as well as LED backlighting of liquid crystal
displays (LCDs) and patents in Phillips LED Luminaire
Licensing Program.” In light of the lack of specificity in
that evidence, it was reasonable for the Board to find that
the licenses were not shown to have a sufficient nexus to
the ’175 patent to require a finding of non-obviousness.
16                                         IN RE: CREE, INC.

                            C
    The final piece of secondary evidence on which Cree
relies is evidence of commercial success. Cree put forward
evidence in the form of a declaration by Dr. Brandes, who
presented sales figures showing the growth of the white
LED market and stated that in his opinion there is a
nexus between the sales figures and the ’175 patent. The
Board found that “Dr. Brandes’ declaration [did] not show
a correlation between the claimed invention and the sales
numbers,” and that his characterization of a nexus “is
nothing more than an allegation or a conclusory state-
ment.”
    When commercial success is cited as a basis for infer-
ring non-obviousness, a nexus must be shown between the
commercial success and the claimed features of the pa-
tent. In re Huang, 100 F.3d 135, 139-40 (Fed. Cir. 1996).
    We agree with the Board that Dr. Brandes’ declara-
tion merely repeats, in conclusory fashion, that there is a
nexus between the success of white LEDs and the claimed
invention. The Board found that the evidence showed
sales of white light products using LEDs with lumino-
phoric substances, such as consumer products incorporat-
ing white LED backlit LCD displays, but that there was
no sufficient showing of a nexus between those sales and
the invention.
    In a portion of the examiner’s answer that was adopt-
ed by the Board, the examiner found that the commercial
success of white LEDs “cannot be due to simply making a
single-die semiconductor LED that emits white light,”
because if that were so, “then the commercialization could
have started back in 1973.” Instead, the examiner found,
“it appears that Wetzel, Redwing, and Stringfellow all
acknowledge the invention of a GaN LED with sufficiently
high light output, somewhere in the UV to blue region of
the spectrum was the thing that made the down-
IN RE: CREE, INC.                                        17

converting device of Stevenson . . . commercial[ly] success-
ful.”
    Cree has failed to rebut the Board’s finding of a lack
of nexus between the invention and the commercial
success of white light LEDs. As the Board found, “the
record is completely silent on whether the commercial
success was caused by the subject matter of the ’175
patent as distinct from the prior art.” For that reason, we
sustain the Board’s conclusion that the evidence of com-
mercial success did not outweigh the strong prima facie
showing of obviousness.
    We therefore uphold the Board’s decision rejecting the
disputed claims of the ’175 patent.
                       AFFIRMED