`____________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`____________
`
`TCL MULTIMEDIA TECHNOLOGY HOLDINGS LIMITED AND
`TTE TECHNOLOGY, INC.,
`Petitioners
`v.
`NICHIA CORPORATION,
`Patent Owner
`____________
`U.S. Patent No. 7,915,631
`
`“Light Emitting Device and Display”
`____________
`Inter Partes Review No. 2017-02000
`____________
`
`DECLARATION OF DR. ERIC BRETSCHNEIDER
`IN SUPPORT OF PETITION FOR INTER PARTES REVIEW OF U.S.
`PATENT NO. 7,915,631
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`TCL 1003, Page 1
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`TABLE OF CONTENTS
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`I.
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`BACKGROUND AND QUALIFICATIONS ................................................... 1
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`II. ASSIGNMENT AND MATERIALS REVIEWED .......................................... 3
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`III. STATE OF THE ART ........................................................................................ 8
`A.
`The Principles of Color Mixing ............................................................ 8
`B. Measuring Color .................................................................................. 10
`C.
`In 1996, YAG Phosphors Were Well Known For Converting
`Blue Emissions To Yellow In Lighting Products ............................... 12
`Emergence of Commercially Viable Blue LEDs ................................ 21
`The Blue Plus Yellow Approach to Making A White LED was
`a Natural And Obvious Progression .................................................... 23
`LED Controllers .................................................................................. 25
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`D.
`E.
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`F.
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`IV. THE ‘631 PATENT .......................................................................................... 26
`A.
`The ‘631 Patent Specification ............................................................. 26
`B.
`The ‘631 Prosecution History ............................................................. 28
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`V.
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`CLAIMS OF THE ‘631 PATENT ................................................................... 28
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`VI. CLAIM CONSTRUCTION ............................................................................. 31
`A. General Legal Standards ..................................................................... 31
`B.
`Terms Requiring Construction ............................................................ 34
`1.
`“transparent material” ............................................................... 34
`2.
`“diffuses” .................................................................................. 35
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`VII. PATENTABILITY ANALYSIS ...................................................................... 36
`A.
`Legal Standards for Patentability ........................................................ 36
`B.
`The Cited Prior Art .............................................................................. 40
`1.
`Baretz ........................................................................................ 40
`2.
`Shimizu ..................................................................................... 40
`3. Matoba....................................................................................... 41
`4.
`Pinnow ...................................................................................... 42
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`E.
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`Nakamura .................................................................................. 43
`5.
`C. Ground 1: Baretz, Shimizu and Matoba Render Claims 1-2, 6,
`and 10-11 Obvious .............................................................................. 44
`b.
`Baretz Discloses Claim 2 .......................................................... 60
`c.
`Baretz Discloses Claim 6 .......................................................... 60
`d.
`Baretz Discloses Claim 10 ........................................................ 60
`e.
`Baretz Discloses Claim 11 ........................................................ 61
`D. Ground 2: Baretz, Shimizu, Matoba, and Pinnow Render
`Claims 4 and 7-8 Obvious ................................................................... 61
`1.
`Baretz, Shimizu, and Pinnow Disclose Claim 4 ....................... 62
`2.
`Pinnow Discloses Claim 7 ........................................................ 70
`3.
`Pinnow Discloses Claim 8 ........................................................ 71
`Ground 3: Baretz, Shimizu, Matoba, and Nakamura Render
`Claim 9 Obvious .................................................................................. 71
`a.
`Nakamura Discloses Claim 9 .................................................... 71
`b.
`A POSITA Would Have Been Motivated To
`Combine Baretz, Shimizu, Matoba, and Nakamura
`And Had a Reasonable Expectation of Success ....................... 72
`Ground 4: Matoba, Shimizu and Pinnow Render Claims 1, 4, 6-
`8, and 10-11 Obvious .......................................................................... 74
`a.
`Independent Claim 1 ................................................................. 75
`b. Matoba, Shimizu, and Pinnow Disclose Claim 4 ..................... 88
`c. Matoba, Shimizu, and Pinnow Disclose Claim 6 ..................... 89
`d. Matoba, Shimizu, and Pinnow Disclose Claim 7 ..................... 89
`e. Matoba, Shimizu, and Pinnow Disclose Claim 8 ..................... 89
`f. Matoba, Shimizu, and Pinnow Disclose Claim 10 ................... 90
`g. Matoba, Shimizu, and Pinnow Disclose Claim 11 ................... 90
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`F.
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`VIII. CONCLUSION ................................................................................................. 90
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`I, Eric Bretschneider, do hereby declare and state as follows:
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`I.
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`BACKGROUND AND QUALIFICATIONS
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`1.
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`I have over 25 years of experience with lighting and LEDs, including a
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`comprehensive background on the full range of LED production technologies,
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`including MOCVD hardware/process, fabrication, LED chip and package testing
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`and reliability, optical design, thermal management, color conversion, and SSL
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`fixture/lamp design, integration, and reliability.
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`2.
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`I am currently the Chief Technology Officer at EB Designs &
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`Technology. In that capacity, I am (among other things) responsible for the design
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`of solid-state lighting technologies for clients ranging from startups to Fortune 100
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`companies.
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`3.
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`I am also currently a member of the University of Florida Department
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`of Chemical Engineering Advisory Board. And I have been a Conference Chair for
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`LED Measurement and Standards. I am also a member of a number of professional
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`societies, including SPIE, Materials Research Society, Illuminating Engineering
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`Society (I am a member of the Science Advisory Panel as well as a member of
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`numerous committees, most notably the IES Test Procedures Committee where I
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`chair the Solid-State Lighting subcommittee).
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`4.
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`Prior to my position at EB Designs & Technology, I served as the
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`Director of Engineering at HeathCo, LLC. In that capacity, I was responsible for
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`advanced technology/product development related to solid state lighting, sensors,
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`notifications and control products.
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`5.
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`Prior to my position as Director of Engineering at HeathCo, I was
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`positioned at the Elec-Tech International Co., Ltd., where I held the positions of
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`Chief Engineer, ETi Lighting Research Institute and VP of Research and
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`Development, ETi Solid State Lighting. In that capacity, my responsibilities
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`included developing all technology and product roadmaps for markets in North
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`America, China, Europe, and Japan.
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`6.
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`Between 2008 and 2011, I was positioned at Lighting Science Group
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`Corp., first as a product development manager, and my responsibilities included
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`developing solid state lighting products, then as VP of Research, and my
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`responsibilities included developing advancedgdtgte LED models for product
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`development and production control.
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`7.
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`Between 2004 and 2008, I was positioned at Toyoda Gosei North
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`America, where I was a sales manager, and my responsibilities included managing
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`and developing LED die and package sales accounts form the eastern region of North
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`America.
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`8.
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`Between 2003 and 2004, I was positioned at Beeman Lighting, where I
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`was Director of Solid State Lighting Engineering, and my responsibilities included
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`leading development of solid state lighting systems and materials.
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`9.
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`I have also authored and presented more than a total of 30 publications,
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`presentations, and seminars, and I am a named inventor on 30 issued patents and
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`over 25 pending patents.
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`10.
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`I have held various other positions, in addition to pursuing my Ph.D
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`between 1989, when I earned my BSE in Chemical Engineering from Tulane
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`University in 1989, and 2003. I earned a Ph.D. in Chemical Engineering from the
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`University of Florida in 1999, where my graduate work focused on development of
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`optoelectronic devices, including novel silicon based visible LEDs and sulfide based
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`TFELD structures and zinc selenide blue LEDs.
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`11. Based on the above education and experience, I believe that I have a
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`detailed understanding of the state of the art during the relevant period, as well as a
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`sound basis for opining how persons of skill in the art at that time would understand
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`the technical issues in this case.
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`12.
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`I presently hold over 30 patents related to LED technology.
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`13. A copy of my curriculum vitae is attached hereto as Appendix A.
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`II. ASSIGNMENT AND MATERIALS REVIEWED
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`14.
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`I submit this declaration in support of the petition for Inter Partes
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`Review of U.S. Patent No. 7,915,631 (“the ‘631 patent”) submitted by TCL
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`Multimedia Technology Holdings Limited and TTE Technology, Inc. (collectively,
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`“TCL”).
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`15.
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`I am not an employee of TCL or of any affiliate or subsidiary thereof.
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`16.
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`I am being compensated for my time at the rate of $650 per hour.
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`17. My compensation is in no way dependent upon the substance of the
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`opinions I offer below, or upon the outcome of TCL’s petition for Inter Partes
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`review (or the outcome of the Inter Partes review, if trial is instituted).
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`18.
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`I have been asked to provide certain opinions relating to the
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`patentability of the ‘631 patent. Specifically, I have been asked to provide my
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`opinions regarding (i) the level of ordinary skill in the art to which the ‘631 patent
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`pertains, and (ii) whether claims 1-2, 4 and 6-11 of the ‘631 patent are anticipated
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`by or would have been obvious in view of the prior art.
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`19. The opinions expressed in this declaration are not exhaustive of my
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`opinions on the patentability of claims 1-2, 4 and 6-11 of the ‘631 patent. Therefore,
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`the fact that I do not address a particular point should not be understood to indicate
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`any opinion on my part that any claim otherwise complies with the patentability
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`requirements.
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`20.
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`In forming my opinions, I have reviewed the ‘631 patent and its
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`prosecution history, and the art cited during its prosecution history, as well as prior
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`art to the ‘631 patent including:
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`a) U.S. Patent No. 6,600,175 (“Baretz”) (Ex. 1005)
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`b) Japanese Examined Patent Application Publication No. H08-7614 (“Ex.
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`1006”)
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`c) Certified Translation of Japanese Examined Patent Application Publication
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`No. H08-7614 (“Shimuzu”) (“Ex. 1007”)
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`d) Japanese Unexamined Patent Application Publication No. H07-99345 (Ex.
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`1008)
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`e) Certified Translation of Japanese Unexamined Patent Application Publication
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`No. H07-99345 (“Matoba”) (Ex. 1009)
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`f) Japanese Laid Open Patent Application Publication No. H05-152609 (Ex.
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`1010)
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`g) Certified Translation of Japanese Laid Open Patent Application Publication
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`No. H05-152609 (“Tadatsu”) (Ex. 1011)
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`h) U.S. Patent No. 3,699,478 to Pinnow et al. (“Pinnow”) (Ex. 1012)
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`i) U.S. Patent No. 3,816,576 to Auzel (“Auzel”) (Ex. 1013)
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`j) U.S. Patent No. 5,796,376 to Banks (“Banks”) (Ex. 1014)
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`k) Nakamura et. al., “High-power InGaN single-quantum-well-structure blue
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`and violet light-emitting diodes,” Appl. Phys. Lett. 67 (13), 25 September
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`1995 (“Nakamura”) (Ex. 1015)
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`l) . Blasse et al., “Luminescent Materials,” Springer-Verlag (New York), 1994
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`(“Blasse”) (Ex. 1016)
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`m) W. O’Mara, “Liquid Crystal Flat Panel Displays,” Van Nostrand Reinhold,
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`New York (1993) (“O’Mara”) (Ex. 1017)
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`n) M. Hoffman, “Improved color rendition in high pressure mercury vapor
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`lamps,” Journal of the Illuminating Engineering Society, Vol. 6 No. 2, Jan.
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`1997 (“Hoffman”) (Ex. 1021)
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`o) U.S. Patent No. 3,691,482 to Pinnow et al. (Ex. 1022)
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`p) H. Rossotti, “Colour,” Princeton University Press, 1983 (Ex. 1023)
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`q) S. Nakamura et al., “Candela-class high brightness InGaN/AlGaN double-
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`heterostructure blue-light emitting diodes,” Applied Physics Letters, No. 64
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`No. 13 (Mar. 28, 1994) (Ex. 1024)
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`r) G. Blasse et al., “A New Phosphor for Flying-Spot Cathode-Ray Tubes for
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`Color Television: Yellow-Emitting Y3Al5O12-Ce3+, Applied Physics Letters,
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`Vol. 11 No. 2 (Jul. 15, 1967) (Ex. 1025)
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`s) G. Blasse et al, “Investigation of Some Ce3+-Activated Phosphors,” The
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`Journal of Chemical Physics, Vol. 47 No. 12 (Dec. 15, 1967) (Ex. 1026)
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`t) D.A. Pinnow et al., “Photoluminescent Conversion of Laser Light for Black
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`and White and Multicolor Displays,” Applied Optics (Jan. 1971) (Ex. 1027)
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`u) Herbert Maruska, Dissertation, Gallium Nitride Light-Emitting Diodes,
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`Chapter 1 (Nov. 1974) (“Maruska”) (Ex. 1028)
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`v) U.S. Patent No. 4,727,283 to van Kemenade et al. (“Phillips”) (Ex. 1026)
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`w) U.S. Patent No. 3,740,570 to Kaelin et al. (“Kaelin”) (Ex. 1030)
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`x) U.S. Patent No. 4,090,189 to Fisler (“Fisler”) (Ex. 1030)
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`y) U.S. Patent No. 3,819,974 to Stevenson et al. (“Stevenson”) (Ex. 1031)
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`21. Likewise, in forming my opinions, I have reviewed the materials listed
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`below:
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`a) German Patent Application No. DE 19638667 A1 to Schlotter et al. (Ex.
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`1018)
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`b) Certified Translation of German Patent Application No. DE 19638667 A1 to
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`Schlotter et al. (“Osram”) (Ex. 1019)
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`c) U.S. Patent No. 7,078,732 to Reeh et al. (Ex. 1020)
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`d) Class for Physics of the Royal Swedish Academy of Sciences, “Efficient Blue
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`Light-Emitting Diodes Leading to Bright and Energy-Saving White Light
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`Sources,” Kungl. Vetenskaps-Akademien (Oct. 7, 2014) (Ex. 1033)
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`e) In re Cree Re-examination Examiner Decision (Ex. 1034)
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`f) Trial Transcript in Everlight et al. v. Nichia Corp. et al., No. 12-cv-11758
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`(E.D.Mich. Apr. 17, 2015) (Ex. 1035)
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`g) U.S. Patent No. 7,531,960 to Shimizu et al (“’960 patent”) (Ex. 1036)
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`h) U.S. Patent No. 5,998,925 to Shimizu et al (“’925 patent”) (Ex. 1037)
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`i) BASF – The Chemical Company: Lumogen® F Yellow 083 Data Sheet (Ex.
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`1038)
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`j) BASF – The Chemical Company: Lumogen® F Orange 240 Data Sheet (Ex.
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`1039)
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`k) Sinloihi’s EL Color Conversion Pigment – FA-000 Series (Ex. 1040)
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`l) Institution Decision in IPR2017-00551 (Ex. 1041)
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`m) Institution Decision in IPR2017-00552 (Ex. 1042)
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`n) Institution Decision in IPR2017-00556 (Ex. 1043)
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`o) Institution Decision in IPR2017-00558 (Ex. 1044)
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`III. STATE OF THE ART
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`A. The Principles of Color Mixing
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`22. Persons of ordinary skill in the art working in lighting are generally
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`focused on three principles: efficiency, lifetime, and quality of light, including the
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`ability to render colors accurately. This has, essentially, been the focus of lighting
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`for over the hundred years, and it has been the particular focus of LED lighting since
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`the creation of the field.
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`23. More generally, individuals have understood for centuries that various
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`colors of light can be created by mixing light. These principles have been well-
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`known for over 300 years since, in 1704, since described by Isaac Newton in 1704;
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`for instance, Newton pointed out that “white” light could be produced by mixing
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`blue and yellow light or by mixing red, green, and blue light. Color is detected in
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`the human eye by cells in the retina that are sensitive to red, green, and blue light.
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`These are the only colors that the human eye is capable of perceiving; all other colors
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`are mixtures of red, green, and blue.
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`24. Different colors and mixes of colors correlate to different given
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`wavelengths, as shown in the following chart:
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`25. For example, as shown in the chart above, light having a wavelength of
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`between 560 and 590 is perceived as shades of yellow, even if the perceived
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`“yellow” light is generated by mixing green and red. Humans perceive white when
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`the red, green, and blue cones within the eye are stimulated roughly equally. This is
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`reflected by white appearing in the center of the color wheel, shown below:
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`26. As shown in the color wheel, white light can be generated in different
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`ways, such as by mixing roughly equal parts red, green, and blue; or by mixing blue
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`and yellow, which itself is a mixture of red and green. In Newton’s paper published
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`in 1704, he described this basic principle – how white can be made either by mixing
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`equal parts red, green, and blue or by combining blue and yellow.
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`B. Measuring Color
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`27. Color technology was developed and refined to the point that the first
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`chromaticity diagrams were developed in the 1920s and 1930s. See generally CIE
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`1931 2° Standard Observer (x-y coordinates). A chromaticity diagram reduces color
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`mixing from an art to a science—precision and reproducibility are possible on such
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`a diagram merely by setting out a set of x,y coordinates. Id. This precision relates
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`to measurement of the light produced by a light source and its interaction with an
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`object under the light source, but not necessarily to subjective human judgment
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`about the quality of a color. Id.
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`28.
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` In particular, in 1931, the International Commission for Illumination
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`(CIE) devised a chromaticity diagram. The CIE is the standards body that defines
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`the “standard observer” and the CIE chromaticity curve. This diagram quantifies
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`the relationship between physical pure colors (e.g., wavelengths) and the visible
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`spectrum, as perceived by the human eye. A line connecting any two primary colors
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`on the x and y axes will show the possible colors visible by combining those two
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`colors. In the below chart, for example, a line drawn between yellow light (550nm)
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`and blue light (450nm) shows that those two colors will combine to make a white
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`light. The “e” at the center of the diagram roughly correlates to a shade of white,
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`although the diagram does not provide a specific definition of any particular white
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`color. Adding more yellow to the blue-yellow combination will produce a more
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`yellowish colored white, while adding more blue will produce a more blueish-
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`colored white.
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`C.
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`In 1996, YAG Phosphors Were Well Known For Converting Blue
`Emissions To Yellow In Lighting Products
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`29. A phosphor absorbs light of one color and emits light of a different
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`color. Because of this unique property, phosphors have been commonly used since
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`at least the 1930s to mix colors. This color mixing is accomplished by placing a
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`phosphor over a light source where the phosphor converts a portion of the light
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`emitted by the light source to a different color and the remainder of light is emitted
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`unaltered. The overall effect is the emission of light of two different colors, which
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`will be perceived by the eye as a mixture of these two colors.
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`30. Color-conversion of LEDs using phosphors, in particular, has been
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`used since at least the 1960s. The first high-efficiency LEDs emitted in infrared,
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`and researchers used phosphors to convert infrared to visible light, including colors
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`like blue and green. Since that time, there has been a continual effort to improve the
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`efficiency of LEDs, find new phosphor materials, and improve the efficiency of
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`phosphor materials. This trend parallels the development of lighting sources and
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`phosphors for fluorescent light, where most efforts were focused on making “white”
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`light because of market expectations. Fluorescent light laid the foundation of
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`conversion from short to long wavelength light.
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`31. As part of the research on color-conversion of light from short to long
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`wavelengths, individual researchers developed materials commonly referred to as
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`“YAG” phosphors (among other rare-earth based phosphors) in the 1960s as one of
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`the finite number of design choices for particular types of conversions. At the time,
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`these researchers were exploring the use of YAG and other rare-earth based
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`phosphors for applications such as fluorescent tubes, incandescent lamps, and
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`displays. Below I set forth just some of the relevant disclosures from this work,
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`showing that YAG was known as proper substance for use in high-temperature
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`environments with high light output, and specifically was suited for use with light
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`of the range of wavelengths that would eventually be produced by GaN or InGaN
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`LEDs:
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` Blasse & Bril, 1967: “Y3Al5O12-Ce shows a bright yellow emission under
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`excitation with cathode rays as well as with blue radiation…. The emission
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`from Y3Al5O12-Ce under cr [cathode ray] excitation … lies almost entirely in
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`the visible with a broad band peaking at 550 nm…. Figure 2 shows that
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`Y3Al5O12-Ce is most efficiently excited by 460 nm radiation. Ex. 1025,53-
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`54. They explained that “YAG is most efficiently excited by 460 nm
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`radiation,” which means that YAG is excited by a blue light source. Id.,54.
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`Another key YAG characteristic was that it showed “a bright yellow
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`emission.” Id.,53.1
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`1 I am very familiar with the Blasse & Bril (June 1967) and Blasse & Bril
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`(December 1967) publications, and have previously reviewed them in a professional
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` Hoffman, 1977: “The YAG:Ce phosphor is not excited by 254 nanometers
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`and only weakly by 365 nanometers from the Hg arc. The excitation spectra
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`… shows the very strong dependence of the emission intensity on the 436-nm
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`Hg radiation.” “The emission of the phosphor is in a band peaking at about
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`540 nanometers at 25° C shifting to about 560 nanometers at 300° C…. This
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`is at the maximum eye sensitivity and close to the calculated peak of 590 nm
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`for good lumen output in the system.” Ex. 1021,89.
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` Pinnow, 1972: “From the compositional standpoint, a preferred embodiment
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`of the invention utilizes a screen coated with cerium-doped yttrium aluminum
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`garnet (YAG) energized by an argon-ion laser arranged so as to emit at 4,880
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`Ǻ. The cerium-activated phosphor emits over a broad range of wavelengths
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`centering about 5,500 Ǻ.”
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` Ex. 1012,1:43-46; see also id.,1:49-56
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`(“Variations include other laser sources, such as a cadmium-ion laser which
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`may emit at 4,416 Ǻ. as well as variations in the phosphor composition. All
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`such compositions are cerium-activated and utilize a host of the garnet
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`capacity prior to my involvement in this proceeding. Based on that review, I have
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`determined that Exhibits 1025 and 1026 are true and correct copies of the Blasse &
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`Bril publications, as were published in 1967. However, I do not rely on either Blasse
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`& Bril reference as prior art, but rather as background to explain the state of the art.
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`structure (i.e.[,] the structure of Y3Al5O12) since this is the only known
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`combination to produce reemission of the appropriate color and brightness.”).
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`• Pinnow et al., 1971: “In order to test some of the above concepts, a display
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`screen was fabricated by dusting YAG:Ce powder over a white cardboard
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`sheet that had been coated with a transparent glue. This screen was used in
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`conjunction with a real time test display system which used an argon ion laser
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`source (4880 Ǻ) and solid state, acoustoopic deflectors.” Ex. 1027,156-157
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`(“Similarly the combination of 4880-A light and converted light from a
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`YAG:Ce phosphor will produce a somewhat yellowish-white appearance
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`since the line connecting these primaries passes above illuminant C. To
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`achieve a truer white with this phosphor requires a shorter laser wavelength
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`such as the less intense 4579-A line of the argon laser or the 4416-A line of
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`the Cd-He laser.” Pinnow et al. (1971) also discloses YAG:Ce emission on a
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`CIE diagram at Figure 1:2
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`2 I am very familiar the Pinnow 1971 publication, and have previously reviewed it
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`in a professional capacity prior to my involvement in this proceeding. Based on that
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`review, I have determined that Exhibit 1027 is a true and correct copy of the Pinnow
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`1971 publication, as was published in 1967. However, I do not rely on Pinnow 1971
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`as prior art, but rather as background to explain the state of the art.
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`TCL 1003, Page 18
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`• Philips, 1988. Describing YAG as well known for its absorption range and
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`efficiency, and ability to reduce color temperature: “A low-pressure mercury
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`vapour discharge lamp of the kind described in the opening paragraph is
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`characterized according to the invention in that the lamp is provided with an
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`absorption layer comprising an aluminate activated by trivalent cerium and
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`having a garnet crystal structure…. The said garnet is a known luminescent
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`material…, which absorbs shortwave ultraviolet radiation, but especially
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`absorbs radiation having a wavelength between about 400 and 480 nm and
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`converts it into radiation in a wide emission band (half-value width of about
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`110 nm) with a maximum at about 560 nm. It has been found that the use of
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`such a luminescent garnet in an absorption layer for three-band fluorescent
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`TCL 1003, Page 19
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`lamps leads to a shift of the colour point of the radiation emitted by the lamp
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`and allows for a reduction of the colour temperature of the lamp…. A
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`reduction of the colour temperature in itself could be attained with any yellow
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`pigment absorbing blue radiation. However, a yellow pigment leads to a
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`reduction (unacceptable for this lamp type) of the relative luminous flux so
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`that it cannot be used. The use of the luminescent garnet in lamps according
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`to the invention has the advantage that the absorbed radiation is no lost, but is
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`converted with a high efficiency into visible radiation so that high relative
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`luminous fluxes are obtained.” Ex. 1029,2:43-60,2:61-3:2.
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`32.
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`In general, the goal was to use YAG and other rare-earth based
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`phosphors to make the light for a given application brighter, making it appropriate
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`for use with lamps, projection displays and other “white light” technology. By the
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`late sixties and early seventies, YAG and other rare-earth based phosphors were
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`standard industrial materials (YAG itself had an industry standard number—“P46”
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`(YAG with cerium) and "P53" (YAG with terbium), and, based on what was known
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`about their characteristics in lighting, they were a standard material to use with any
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`high-intensity blue light source because they allowed for broad emission and
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`potentially improved quality of light.
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`33.
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`Indeed, as described above, since its discovery in the 1960s, YAG
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`became the go-to phoshor to create white light from a blue light source. In 1969,
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`TCL 1003, Page 20
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`researchers were using YAG with, for instance, argon-ion laser beams which
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`produced blue light, and it was well understood that YAG-type phosphors would
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`work well with light within particular wavelength ranges, as described in the
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`references cited immediately above. Likewise, in the 1970s, GE applied YAG to
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`another commercially viable blue light source – mercury vapor lamps – as described
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`in Hoffman above. Mercury vapor lamps emit light in the blue color region, with
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`some lamps emitting too much blue. Similarly, Phillips taught the use of YAG
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`Phosphors with blue mercury vapor lamps to “emit white light at a given color
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`temperature.” Ex.1029,1:40-41, 3:9-18.
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`34. These earlier publications also taught that YAG withstands harsh
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`operating conditions. For instance, Hoffman taught that the temperature in mercury
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`vapor lamps was 300° C. Ex. 1021,p. 91. The Pinnow references disclose the use
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`of YAG with a laser that has anywhere from 50 to over 600 times the intensity of
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`sunlight. Ex. 1027,p. 154. Blasse and Bril taught the use of YAG with cathode ray
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`tubes, which would have been known to have a high radiation density. Ex. 1025,pp.
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`53-54.
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`35. Thus, by the early seventies, YAG and other rare-earth based phosphors
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`were standard industrial materials (YAG itself had an industry standard number—
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`“P46” (YAG with cerium) and "P53" (YAG with terbium), and, based on what was
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`known about their characteristics in lighting, they were a standard material to use
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`TCL 1003, Page 21
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`with any high-intensity blue light source because they allowed for broad emission
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`and potentially improved quality of light. YAG had been used by two of largest
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`lighting companies in the world (Philips and GE) and one of the leading research
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`laboratories in the U.S. (Bell Labs) to partially down-convert blue light emission
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`into yellow light in order to make white light.
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`36. At roughly the same time, researchers such as Stevenson and Maruska
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`were working to grow GaN materials structures for use in blue LEDs. See, e.g.,
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`Herbert Maruska, Dissertation, Gallium Nitride Light-Emitting Diodes, Chapter 1
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`(Nov. 1974) (Ex. 1028); U.S. Patent No. 3,819,974 (Ex. 1032) (June 25, 1974 (listing
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`inventors David A. Stevenson, Walden C. Rhines, and Herbert P Maruska)). By the
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`mid-1970s, individuals understood that LEDs will be the light source of the future,
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`given the potential efficiency, lifetime, and ability to create all colors of light by
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`color-conversion techniques such as the use of phosphors with the LEDs. Early
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`development in this field produced bright infrared LEDs (which were used with
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`upconverting phosphors), and then yellow and green LEDs. It was understood that,
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`charting out the development of the field, that what was needed was an efficient blue
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`LED light source, as that would allow for the creation of “white” light using standard
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`color-converting/color mixing
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`techniques,
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`including using standard down-
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`TCL 1003, Page 22
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`converting phosphors like YAG or other rare-earth phosphors.3 The researchers in
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`this field were generally a small group who were well aware of various developments
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`and work toward creating blue LEDs. Prior to the development of blue LEDs into
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`high intensity light sources, much progress was made getting existent LEDs to
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`produce brighter light by controlling starting materials and reducing impurity levels
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`in the materials.
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`37. To make blue LEDs, individuals worked with a variety of materials,
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`including zinc selenide, zinc sulfide, silicon carbide, and boron nitride. For instance,
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`within the zinc selenide line of development, Sumitomo eventually developed an
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`elegant solution to creating white light by using a zinc selenide chip and a phosphor
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`substrate. Additionally, researchers working with wide band-gap materials and
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`structures to create blue LEDs began to use down-converting phosphors to convert
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`the light.
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`38. What developed within the field was that every time a new LED light
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`source was developed, researchers suggested using a phosphor with that light source
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`3 Down-conversion” refers to converting a light emission to a lower frequency
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`emission and thus a higher wavelength, e.g., converting blue light at 450 nm
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`wavelength to yellow light at 570 nm. Partial down-conversions means that some
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`the original light (e.g., blue) is not converted.
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`TCL 1003, Page 23
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`that matched the light source's emission in order to make other colors. This is
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`straightforward, because the ability to make a variety of colors is what is useful in
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`the industry, and generally what will meet market expectations and trends.
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`Accordingly, it was entirely predictable that as researchers developed new LED light
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`sources, they would try, as a matter of course, those proven materials such as rare-
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`earth-type phosphors (including YAG) with them, and would have an expectation
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`that t