111111
`
`1111111111111111111111111111111111111111111111111111111111111
`US007531960B2
`
`c12) United States Patent
`Shimizu et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7,531,960 B2
`May 12,2009
`
`(54) LIGHT EMITTING DEVICE WITH BLUE
`LIGHT LED AND PHOSPHOR COMPONENTS
`
`(58) Field of Classification Search ......... 313/498-512;
`428/690; 257/103
`See application file for complete search history.
`
`(75)
`
`Inventors: Yoshinori Shimizu, Tokushima (JP);
`Kensho Sakano, Arran (JP); Yasunobu
`Noguchi, Tokushima (JP); Toshio
`Moriguchi, Arran (JP)
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`3,510,732 A
`
`5/1970 Amans
`
`(73) Assignee: Nichia Corporation, Anan-shi (JP)
`
`( *) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 233 days.
`
`(21) Appl. No.: 11/682,014
`
`(22) Filed:
`
`Mar. 5, 2007
`
`(65)
`
`Prior Publication Data
`
`US 2007/0159060Al
`
`Jul. 12, 2007
`
`Related U.S. Application Data
`
`(62) Division of application No. 10/609,402, filed on Jul. 1,
`2003, now Pat. No. 7,362,048, which is a division of
`application No. 09/458,024, filed on Dec. 10, 1999,
`now Pat. No. 6,614,179, which is a division of appli(cid:173)
`cationNo. 09/300,315, filedonApr. 28, 1999, now Pat.
`No. 6,069,440, which is a division of application No.
`08/902,725, filed on Jul. 29, 1997, now Pat. No. 5,998,
`925.
`
`(30)
`
`Foreign Application Priority Data
`
`Jul. 29, 1996
`Sep. 17, 1996
`Sep. 18, 1996
`Dec. 27, 1996
`Mar. 31, 1997
`
`(JP)
`(JP)
`(JP)
`(JP)
`(JP)
`
`.............................. P 08-198585
`.............................. P 08-244339
`.............................. P 08-245381
`.............................. P 08-359004
`.............................. P 09-081010
`
`(51)
`
`Int. Cl.
`HOSB 33100
`(2006.01)
`(52) U.S. Cl. ........................ 313/512; 257/103; 428/690
`
`(Continued)
`
`FOREIGN PATENT DOCUMENTS
`
`DE
`
`3804293 A1
`
`8/1989
`
`(Continued)
`
`OTHER PUBLICATIONS
`
`Branko et a!., Development and applications of highbright white
`LED lamps, Nov. 29, 1996, The 264th Proceedings of the Institute of
`Phosphor Society, pp. 4-16 of the English translation.
`
`(Continued)
`
`Primary Examiner-Joseph L Williams
`(74) Attorney, Agent, or Firm-Birch, Stewart, Kolasch &
`Birch, LLP
`
`(57)
`
`ABSTRACT
`
`A light emitting device includes a light emitting component;
`and a phosphor capable of absorbing a part oflight emitted by
`the light emitting component and emitting light of a wave(cid:173)
`length different from that of the absorbed light. A straight line
`connecting a point of chromaticity corresponding to a peak of
`the spectrum generated by the light emitting component and
`a point of chromaticity corresponding to a peak of the spec(cid:173)
`trum generated by the phosphor is disposed along with the
`black body radiation locus in the chromaticity diagram.
`
`23 Claims, 19 Drawing Sheets
`
`200
`
`203
`
`202
`
`201
`
`204
`
`205
`
`TCL 1036, Page 1
`
`

`

`U.S. PATENT DOCUMENTS
`
`3,652,956 A
`3,691,482 A
`3,699,478 A
`3,819,974 A
`3,875,456 A
`4,298,820 A
`4,314,910 A
`4,550,256 A
`4,644,223 A
`4,716,337 A
`4,727,283 A
`4,905,060 A
`5,006,908 A
`5,118,985 A
`5,202,777 A
`5,257,049 A
`5,369,289 A
`5,471,113 A
`5,550,657 A
`5,578,839 A
`5,602,418 A
`5,700,713 A
`5,798,537 A
`5,825,125 A
`5,847,507 A
`5,959,316 A
`6,004,001 A
`6,066,861 A
`6,538,371 Bl
`6,576,930 B2
`6,784,511 Bl
`6,812,500 B2
`200110030326 AI
`
`3/1972 Pinnow et al.
`9/1972 Pinnow et al.
`10/1972 Pinnow et al.
`6/1974 Stevenson et a!.
`4/1975 Kano eta!.
`1111981 Bongers et al.
`2/1982 Barnes
`10/1985 Berkstesser et a!.
`2/1987 de Hair et al.
`12/1987 Huiskes et al.
`2/1988 van Kemenade et al.
`2/1990 Chinone et a!.
`4/1991 Matsuoka et a!.
`6/1992 Patton eta!.
`4/1993 Sluzky et al.
`10/1993 Van Peteghem
`1111994 Tarnaki et al.
`1111995 De Backer et al.
`8/1996 Tanaka eta!.
`1111996 Nakamura et a!.
`2/1997 Imai et al.
`12/1997 Yamazaki et a!.
`8/1998 Nitta
`10/1998 Ligthart et a!.
`12/1998 Butterworth et a!.
`9/1999 Lowery
`12/1999 Noll
`5/2000 Hohn et al.
`3/2003 Duggal eta!.
`6/2003 Reeh eta!.
`8/2004 Kunihara et a!.
`1112004 Reeh eta!.
`10/2001 Reeh eta!.
`
`FOREIGN PATENT DOCUMENTS
`9013615 u
`0 209 942 Al
`0 383 215 A
`0 500 937 Al
`0 541 373 A2
`0 667 383 A2
`1305111
`2 000 173 A
`1589964
`4717684
`49106283
`5079379
`491221
`49112577
`49-122292
`5043913 Cl
`5245181
`53-7153
`5331584
`5472484
`5441660
`55-4898 A
`55-005533 A
`554898 A
`59-30107 u
`5950445
`60144381
`60-185457 A
`62189770
`61-158606
`62-20237 A
`62167387
`621673987
`62-232827 A
`291980
`
`111991
`111987
`8/1990
`9/1992
`1111992
`8/1995
`111973
`111979
`5/1981
`9/1972
`12/1972
`1111973
`111974
`10/1974
`1111974
`4/1975
`10/1977
`111978
`3/1978
`1111978
`12/1979
`111980
`111980
`111980
`2/1984
`4/1984
`7/1985
`9/1985
`2/1986
`7/1986
`111987
`7/1987
`7/1987
`10/1987
`9/1988
`
`DE
`EP
`EP
`EP
`EP
`EP
`GB
`GB
`GB
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`
`US 7,531,960 B2
`Page 2
`
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`wo
`wo
`
`01-189695 A
`01179471 A
`01-257993 A
`01-260707 A
`02-111922 A
`324692
`03-152898 A
`4-80286 A
`463162
`463163
`4-234481 A
`5-226676
`05-142424 A
`5152609 A
`05152609 A
`5183189 A
`05-63068 u
`563068
`06-027327 A
`06-82633 A
`6-115158
`06-139973 A
`0 599 224 Al
`06-160635 A
`06-177423 A
`06177423
`6208845
`06-231605 A
`06260680
`06268257
`7-99345 A
`07-114904 A
`07-120754 A
`7-32638 u
`7-42152 u
`742152
`07176794 A
`07-235207 A
`07-288341
`7-321407
`08007614 A
`8-78727 A
`863119
`8170077
`09-027642 A
`09027642 A
`10036835 A
`11-500584
`2000-512806
`2001-320094 A
`2002-270020 A
`97/50132 Al
`98/12757 Al
`
`7/1989
`7/1989
`10/1989
`10/1989
`4/1990
`3/1991
`6/1991
`3/1992
`5/1992
`5/1992
`8/1992
`3/1993
`6/1993
`6/1993
`6/1993
`7/1993
`8/1993
`8/1993
`2/1994
`3/1994
`4/1994
`5/1994
`6/1994
`6/1994
`6/1994
`6/1994
`7/1994
`8/1994
`9/1994
`9/1994
`4/1995
`5/1995
`5/1995
`6/1995
`7/1995
`7/1995
`7/1995
`9/1995
`10/1995
`12/1995
`111996
`3/1996
`3/1996
`7/1996
`111997
`111997
`2/1998
`111999
`9/2000
`1112001
`9/2002
`12/1997
`3/1998
`
`OTHER PUBLICATIONS
`
`Nikkei Sangyo Shin-bun ofSep. 13, 1996.
`S. Nakaura eta!., Japanese Journal of Applied Physics Part 2, vol. 31,
`No. lOB, 1992, pp. Ll457-Ll459.
`Mitsubishi Electric Company Technical Report, vol. 48, No.9, 1974,
`pp. 1121-1124.
`Proceedings of Illumination National Convention in 1983, p. 12.
`Phosphor Handbook, 1st Edition, 1987, pp. 233-240 and 275-277.
`Journal of the Television Society, vol. 47, No.5, 1993, pp. 753-764.
`R. W. G. Hunt, Color Research & Application, vol. 16, No.3, 1991,
`pp. 146-165.
`Y. Nayatani, Color Research &Application, vol. 20, No.3, Jun. 1995,
`pp. 143-155.
`M. Ikeda eta!., Color Research & Application, vol. 14, No.4, Aug.
`1989, pp. 198-206.
`M. Ikeda et al., Color Research & Application, vol. 16, No.2, Apr.
`1991, pp. 72-80.
`
`TCL 1036, Page 2
`
`

`

`US 7,531,960 B2
`Page 3
`
`H. Shinoda eta!., Color Research & Application, vol. 18, No.5, Oct.
`1993, pp. 326-333.
`M. Ikeda, Journal ofthe Illumination Society, vol. 71, No. 10, 1987,
`pp. 612-617 and English Abstract.
`P. Schlouer eta!. "Luminescence Conversion of Blue Light Emitting
`Diodes", Applied Physics Letter, vol. 46, p. 417-418, Feb. 1997.
`M.F. Yan eta!., Preparation ofY3Al5012-Based Phosphor Powders,
`J. Electrochem. Soc., vol. 134, No.2, Feb. 1987.
`"Proceedings of the Institute ofPhosphor Society", Translation ofpp.
`1, 5 to 14 of the 264th Proceedings of the Institute of Phosphor
`Society, Nov. 29, 1996.
`Shigeo Shionoya eta!. (editors), "Phosphor Handbook", pp. 505-508,
`CRC Press, 1999.
`E.F. Gibbons eta!., "Some Factors Influencing the Luminous Decay
`Characteristics ofY3Al5012:Ce3+", J. Electrochem. Soc., vol. 120,
`No.6, Jun. 1973.
`D.J. Robbins eta!., "Lattice Defects and Energy Transfer Phenomena
`in Y3Al5012:Ce3+", pp. 1004-1013, printed Jun. 19, 2001.
`"White LED lamp: Efficient light-emitting; Manufacture cost half',
`Nikkei Sangyo Shimbun, Sep. 13, 1996, Published by Nihon Keizai
`Shimbunsha.
`Shuji Nakamura, "InGaN/ AlGaNblue-light-emitting diodes", J. Vac.
`Sci. Techno!. A 13(3), May/Jun. 1995, pp. 705-710.
`Shuji Nakamura et a!., "Si-Doped InGaN Films Grown on GaN
`Films", Jpn. J. Appl. Phys. vol. 32 (1993), pp. Ll6-Ll9, Part 2, No.
`1A/B, Jan. 15, 1993.
`"P-GaN/N-InGaN/N-GaN Double(cid:173)
`Shuji Nakamura et a!.,
`Heterostructure Blue-Light-Emitting Diodes", Jpn. J. Appl. Phys.
`vol. 32 (1993), pp. L8-Ll1, Part 2, No. 1A/B, Jan. 15 1993.
`Shuji Nakamura, "Zn-doped InGaN growth and InGaN/AlGaN
`double-heterostructure blue-light-emitting diodes", Journal of Crys(cid:173)
`tal Growth, 145 (1994), pp. 911-917.
`Shuji Nakamura,
`InGaN/AlGaN Double(cid:173)
`"High-Power
`Heterostructure Blue-Light-Emitting Diodes", IEDM 94 (1994),
`IEEE, pp. 567-570.
`Kozo Osamura eta!., "Preparation and optical properties of Ga1-
`xlnxN thin films", Journal of Applied Physics, vol. 46, No. 8, Aug.
`1975, pp. 3432-3437.
`Takashi Matsuoka et a!., "Growth and Properties of a Wide-Gap
`Semiconductor InGaN", Optoelectronics-Devices and Technologies,
`vol. 5, No. 1, pp. 53-64, Jun. 1990.
`T. Nagatomo eta!., "Ga1-xlnxN Blue Light-Emitting Diodes", Proc.
`Electrochem. Soc., 1993, vol. 93-10, pp. 136-141.
`G. Blasse eta!., "Investigation of Some Ce3+-Activated Phosphors",
`Journal of Chemical Physics, vol. 47, No. 12, Dec. 15, 1967.
`
`et a!.,
`Jr.
`W.W. Holloway,
`"On The Fluorescence of
`Cerium-Activated Garnet Crystals", Physics Letters, vol. 25A, No.
`8, Oct. 23, 1967, pp. 614-615.
`E.F. Gibbons eta!., "Some Factors Influencing the Luminous Decay
`Characteristics ofY3Al5012:Ce3+", J. Electrochem. Soc., vol. 120,
`No.6.
`W.J. Miniscalco eta!., "Measurements of Excited-State Absorption
`in Ce3+:YAGa)", J. Appl. Phys. vol. 49, No. 12, Dec. 1978, pp.
`6109-6111.
`D.J. Robbins eta!., "Lattice Defects and Energy Transfer Phenomena
`in Y3Al5012:Ce3+", pp. 1004-1013.
`J.M. Robertson, et a!., "Colourshift of the Ce3+ Emission in
`Monocrystalline Epitaxially Grown Garnet Layers", 1981 Philips J.
`Res. 36, pp. 15-30.
`"Nichia Chemical starts the sample shipment of white light emitting
`diode", News Report, translation ofp. 15 of Nikkei Electronics Sep.
`23, 1996 (No. 671).
`Tadao Miura, Electronics Engineering, "High-intensity White
`Backlighting for LCD of Car Audios", Jul. 1996, vol. 38, No.7, pp.
`55-58.
`Shigeo Shionoya eta!. (editors), "Phosphor Handbook", pp. 505-508,
`CRC Press.
`M.F. Yan eta!., Preparation ofY3Al5012-Based Phosphor Powders,
`J. Electrochem. Soc., vol. 134, No.2.
`"Proceedings of the Institute ofPhosphor Society", Translation ofpp.
`1, 5 to 14 of the 264th Proceedings of the Institute of Phosphor
`Society.
`"A New Phosphor for Flying-Spot Cathode-Ray Tubes for Color
`Television: Yellow Emitting ... ", G. Blasse et al., App. Phys. Lett.
`vol. 11, No.2, pp. 53-55 (1967).
`Glasse et a!., Applied Physics Letters, vol. 11, No. 2, pp. 53-54
`(1967).
`Hoffman, Journal of les, pp. 89-91 ( 1977).
`Nakamura, SPIE, vol. 3002, pp. 26-35 (1997).
`"Simens SMT-TOPLED fur die Oberflachenmontage" Frank
`Mollmer eta!. Simens Components, 29 (1991) Hfet 4.
`"GaNpn Contact Blue/Ultraviolet light Emitting Diode", H. Amano
`eta!., Applied Physics, vol. 20, No.2, pp. 163-166 (1991).
`"Phosphors Based on Rare-Earths, A New Era in Fluorescent Light(cid:173)
`ing", B.M.J. Smets, Materials Chemistry and Physics, 16 pp. 283-299
`(1987).
`W.W. Holloway, Jr. eta!., "Optical Properties of Cerium-Activated
`Garnet Crystals", 1969 Journal of the Optical Society of America,
`vol. 59, No. 1, pp. 60-63.
`Wustlich Mikro-/Opto-Elektronik GMBH (1994/1995).
`Sato eta!., Japanese Journal of Applied Physics, vol. 35, Jul. 1, 1996,
`pp. L838-L839.
`
`TCL 1036, Page 3
`
`

`

`U.S. Patent
`
`May 12,2009
`
`Sheet 1 of 19
`
`US 7,531,960 B2
`
`Fig.1
`
`100
`
`103
`
`101
`
`104
`
`102
`
`105a} 105
`105b
`
`Fig.2
`200
`
`203
`
`201
`
`204
`
`205
`
`TCL 1036, Page 4
`
`

`

`U.S. Patent
`
`May 12,2009
`
`Sheet 2 of 19
`
`US 7,531,960 B2
`
`Fig.3A
`
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`TCL 1036, Page 5
`
`

`

`U.S. Patent
`US. Patent
`
`May 12,2009
`May 12, 2009
`
`Sheet 3 of 19
`Sheet 3 0f 19
`
`US 7,531,960 B2
`US 7,531,960 B2
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`

`U.S. Patent
`
`May 12,2009
`
`Sheet 4 of 19
`
`US 7,531,960 B2
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`TCL 1036, Page 7
`
`

`

`U.S. Patent
`
`May 12,2009
`
`Sheet 5 of 19
`
`US 7,531,960 B2
`
`Fig.6
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`
`

`

`U.S. Patent
`
`May 12,2009
`
`Sheet 6 of 19
`
`US 7,531,960 B2
`
`Fig.7
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`TCL 1036, Page 9
`
`

`

`U.S. Patent
`
`May 12,2009
`
`Sheet 7 of 19
`
`US 7,531,960 B2
`
`Fig.10
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`TCL 1036, Page 10
`
`

`

`U.S. Patent
`
`May 12, 2009
`
`Sheet 8 of 19
`
`US 7,531,960 B2
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`TCL 1036, Page 11
`
`

`

`U.S. Patent
`
`May 12,2009
`
`Sheet 9 of 19
`
`US 7,531,960 B2
`
`Fig.13A
`
`Life test
`lf=20mA Ta=25°C
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`120
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`TCL 1036, Page 12
`
`

`

`U.S. Patent
`
`May 12,2009
`
`Sheet 10 of 19
`
`US 7,531,960 B2
`
`Fig.14A
`
`Weathering test
`100 - - - - - - - - - - -
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`TCL 1036, Page 13
`
`

`

`U.S. Patent
`
`May 12,2009
`
`Sheet 11 of 19
`
`US 7,531,960 B2
`
`Fig.15A
`120
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`Reliability test
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`TCL 1036, Page 14
`
`

`

`U.S. Patent
`U.S. Patent
`
`May 12,2009
`May 12, 2009
`
`Sheet 12 of 19
`Sheet 12 0f 19
`
`US 7,531,960 B2
`US 7,531,960 B2
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`TCL 1036, Page 15
`
`

`

`U.S. Patent
`
`May 12,2009
`
`Sheet 13 of 19
`
`US 7,531,960 B2
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`

`

`U.S. Patent
`
`May 12,2009
`
`Sheet 14 of 19
`
`US 7,531,960 B2
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`TCL 1036, Page 17
`
`

`

`U.S. Patent
`
`May 12,2009
`
`Sheet 15 of 19
`
`US 7,531,960 B2
`
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`TCL 1036, Page 18
`
`

`

`U.S. Patent
`
`May 12,2009
`
`Sheet 16 of 19
`
`US 7,531,960 B2
`
`Fig.20A
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`TCL 1036, Page 19
`
`/
`
`

`

`U.S. Patent
`
`May 12,2009
`
`Sheet 17 of 19
`
`US 7,531,960 B2
`
`Fig.21A
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`TCL 1036, Page 20
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`

`

`U.S. Patent
`
`May 12,2009
`
`Sheet 18 of 19
`
`US 7,531,960 B2
`
`Fig.22A
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`TCL 1036, Page 21
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`
`

`

`U.S. Patent
`
`May 12,2009
`
`Sheet 19 of 19
`
`US 7,531,960 B2
`
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`TCL 1036, Page 22
`
`

`

`US 7,531,960 B2
`
`1
`LIGHT EMITTING DEVICE WITH BLUE
`LIGHT LED AND PHOSPHOR COMPONENTS
`
`This application is a 37 C.P.R. § 1.53(b) divisional of U.S.
`application No. 10/609,402, filed Jul. 1, 2003, now U.S. Pat.
`No. 7,362,048 which is a divisional of U.S. application Ser.
`No. 09/458,024, filed Dec. 10, 1999, now U.S. Pat. No. 6,614,
`179 which is a divisional ofU.S. application Ser. No. 09/300,
`315, filed on Apr. 28, 1999, now U.S. Pat. No. 6,069,440,
`which is a divisional ofU.S. application Ser. No. 08/902,725,
`filed on Jul. 29, 1997, now U.S. Pat. No. 5,998,925, the entire
`contents of which are hereby incorporated by reference.
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`The present invention relates to a light emitting diode used
`in LED display, back light source, traffic signal, trailway
`signal, illuminating switch, indicator, etc. More particularly,
`it relates to a light emitting device (LED) comprising a phos(cid:173)
`phor, which converts the wavelength of light emitted by a
`light emitting component and emits light, and a display
`device using the light emitting device.
`2. Description of Related Art
`A light emitting diode is compact and emits light of clear 25
`color with high efficiency. It is also free from such a trouble as
`bum-out and has good initial drive characteristic, high vibra(cid:173)
`tion resistance and durability to endure repetitive ON/OFF
`operations, because it is a semiconductor element. Thus it has
`been used widely in such applications as various indicators 30
`and various light sources. Recently light emitting diodes for
`RGB (red, green and blue) colors having ultra-high lumi(cid:173)
`nance and high efficiency have been developed, and large
`screen LED displays using these light emitting diodes have
`been put into use. The LED display can be operated with less 35
`power and has such good characteristics as light weight and
`long life, and is therefore expected to be more widely used in
`the future.
`Recently, various attempts have been made to make white
`light sources by using light emitting diodes. Because the light
`emitting diode has a favorable emission spectrum to generate
`monochromatic light, making a light source for white light
`requires it to arrange three light emitting components ofR, G
`and B closely to each other while diffusing and mixing the
`light emitted by them. When generating white light with such
`an arrangement, there has been such a problem that white
`light of the desired tone cannot be generated due to variations
`in the tone, luminance and other factors of the light emitting
`component. Also when the light emitting components are
`made of different materials, electric power required for driv- 50
`ing differs from one light emitting diode to another, making it
`necessary to apply different voltages different light emitting
`components, which leads to complex drive circuit. Moreover,
`because the light emitting components are semiconductor
`light emitting components, color tone is subject to variation 55
`due to the difference in temperature characteristics, chrono(cid:173)
`logical changes and operating enviroument, or unevenness in
`color may be caused due to failure in uniformly mixing the
`light emitted by the light emitting components. Thus light
`emitting diodes are effective as light emitting devices for 60
`generating individual colors, although a satisfactory light
`source capable of emitting white light by using light emitting
`components has not been obtained so far.
`In order to solve these problems, the present applicant
`previously developed light emitting diodes which convert the 65
`color oflight, which is emitted by light emitting components,
`by means of a fluorescent material disclosed in Japanese
`
`2
`PatentKokai Nos. 5-152609,7-99345,7-176794 and 8-7614.
`The light emitting diodes disclosed in these publications are
`such that, by using light emitting components of one kind, are
`capable of generating light of white and other colors, and are
`constituted as follows.
`The light emitting diode disclosed in the above gazettes are
`made by mounting a light emitting component, having a large
`energy band gap of light emitting layer, in a cup provided at
`the tip of a lead frame, and having a fluorescent material that
`10 absorbs light emitted by the light emitting component and
`emits light of a wavelength different from that of the absorbed
`light (wavelength conversion), contained in a resin mold
`which covers the light emitting component.
`The light emitting diode disclosed as described above
`15 capable of emitting white light by mixing the light of a plu(cid:173)
`rality of sources can be made by using a light emitting com(cid:173)
`ponent capable of emitting blue light and molding the light
`emitting component with a resin including a fluorescent
`material that absorbs the light emitted by the blue light emit-
`20 ting diode and emits yellowish light.
`However, conventional light emitting diodes have such
`problems as deterioration of the fluorescent material leading
`to color tone deviation and darkening of the fluorescent mate(cid:173)
`rial resulting in lowered efficiency of extracting light. Dark(cid:173)
`ening here refers to, in the case of using an inorganic fluores(cid:173)
`cent material such as (Cd, Zn)S fluorescent material, for
`example, part of metal elements constituting the fluorescent
`material precipitate or change their properties leading to col-
`oration, or, in the case of using an organic fluorescent mate(cid:173)
`rial, coloration due to breakage of double bond in the mol(cid:173)
`ecule. Especially when a light emitting component made of a
`semiconductor having a high energy band gap is used to
`improve the conversion efficiency of the fluorescent material
`(that is, energy of light emitted by the semiconductor is
`increased and number of photons having energies above a
`threshold which can be absorbed by the fluorescent material
`increases, resulting in more light being absorbed), or the
`quantity of fluorescent material consumption is decreased
`(that is, the fluorescent material is irradiated with relatively
`40 higher energy), light energy absorbed by the fluorescent
`material inevitably increases resulting in more significant
`degradation of the fluorescent material. Use of the light emit(cid:173)
`ting component with higher intensity oflight emission for an
`extended period of time causes further more significant deg-
`45 radation of the fluorescent material.
`Also the fluorescent material provided in the vicinity of the
`light emitting component may be exposed to a high tempera(cid:173)
`ture such as rising temperature of the light emitting compo(cid:173)
`nent and heat transmitted from the external environment (for
`example, sunlight in case the device is used outdoors).
`Further, some fluorescent materials are subject to acceler(cid:173)
`ated deterioration due to combination of moisture entered
`from the outside or introduced during the production process,
`the light and heat transmitted from the light emitting compo(cid:173)
`nent.
`When it comes to an organic dye of ionic property, direct
`current electric field in the vicinity of the chip may cause
`electrophoresis, resulting in a change in the color tone.
`
`SUMMARY OF THE INVENTION
`
`Thus, an object of the present invention is to solve the
`problems described above and provide a light emitting device
`which experiences only extremely low degrees of deteriora(cid:173)
`tion in emission light intensity, light emission efficiency and
`color shift over a long time of use with high luminance.
`TCL 1036, Page 23
`
`

`

`US 7,531,960 B2
`
`25
`
`3
`The present applicant completed the present invention
`through researches based on the assumption that a light emit(cid:173)
`ting device having a light emitting component and a fluores(cid:173)
`cent material must meet the following requirements to
`achieve the above-mentioned object.
`The light emitting component must be capable of emitting
`light of high luminance with light emitting characteristic
`which is stable over a long time of use.
`The fluorescent material being provided in the vicinity of
`the high-luminance light emitting component, must show 10
`excellent resistance against light and heat so that the proper(cid:173)
`ties thereof do not change even when used over an extended
`period of time while being exposed to light of high intensity
`emitted by the light emitting component (particularly the
`fluorescent material provided in the vicinity of the light emit- 15
`ting component is exposed to light of a radiation intensity as
`high as about 30 to 40 times that of sunlight according to our
`estimate, and is required to have more durability against light
`as light emitting component of higher luminance is used).
`With regard to the relationship with the light emitting com- 20
`ponent, the fluorescent material must be capable of absorbing
`with high efficiency the light of high monochromaticity emit(cid:173)
`ted by the light emitting component and emitting light of a
`wavelength different from that of the light emitted by the light
`emitting component.
`Thus the present invention provides a light emitting device,
`comprising a light emitting component and a phosphor
`capable of absorbing a part of light emitted by the light
`emitting component and emitting light of wavelength differ(cid:173)
`ent from that of the absorbed light;
`wherein said light emitting component comprises a nitride
`compound semiconductor represented by the formula: In,Ga1
`AI~ where 0~1, O~j, O~kand i+j+k=1) and said phosphor
`contains a garnet fluorescent material comprising at least one
`element selected from the group consisting ofY, Lu, Sc, La,
`Gd and Sm, and at least one element selected from the group
`consisting of AI, Ga and In, and being activated with cerium.
`The nitride compound semiconductor (generally repre(cid:173)
`sented by chemical formula In,Ga1Al~ where 0~1, O~j,
`O~k and i+j+k=1) mentioned above contains various mate(cid:173)
`rials including InGaN and GaN doped with various impuri(cid:173)
`ties.
`The phosphor mentioned above contains various materials
`defined as described above, including Y3Al5 0 12:Ce and 45
`Gd3In50 12:Ce.
`Because the light emitting device of the present invention
`uses the light emitting component made of a nitride com(cid:173)
`pound semiconductor capable of emitting light with high
`luminance, the light emitting device is capable of emitting
`light with high luminance. Also the phosphor used in the light
`emitting device has excellent resistance against light so that
`the fluorescent properties thereof experience less chang