818 F.3d 694 (Fed. Cir. 2016), 2015-1365, In re Cree, Inc.

Docket Nº:2015-1365
Citation:818 F.3d 694, 118 U.S.P.Q.2d 1253
Opinion Judge:Bryson, Circuit Judge.
Party Name:IN RE: CREE, INC., Appellant
Attorney:WILLIAM F. LEE, Wilmer Cutler Pickering Hale and Dorr LLP, Boston, MA, argued for appellant. Also represented 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 ...
Judge Panel:Before CHEN, CLEVENGER, and BRYSON, Circuit Judges.
Case Date:March 21, 2016
Court:United States Courts of Appeals, Court of Appeals for the Federal Circuit

Page 694

818 F.3d 694 (Fed. Cir. 2016)

118 U.S.P.Q.2d 1253

IN RE: CREE, INC., Appellant


United States Court of Appeals, Federal Circuit

March 21, 2016

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


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.


[ 118U.S.P.Q.2D 1254] Bryson, Circuit Judge.

This is an appeal from a decision of the Patent Trial and Appeal Board in an ex parte reexamination proceeding. The Board held various claims of a patent owned by Cree, Inc., to be unpatentable as obvious. We affirm.


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 production 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 reexamination of the '175 patent as obvious under multiple combinations of prior art references, including the combination 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 recipient 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 dispersed in a polymer that is on or about the single-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 emitted by the solid state device emits light in the white visible light spectrum by fluorescence and/or phosphorescence." In the context of lamps and other lighting applications, 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.

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 phosphor (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 [ 118U.S.P.Q.2D 1255] 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 wavelength light emitted by various phosphors. Pinnow explains that " a necessary condition for achieving a true white is that the illuminating laser beam have a wavelength 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." Stevenson 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 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 Stevenson'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 replacing 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...

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