LIGHT EMITTING DEVICE AND DISPLAY

• US 20110297990A1
• Filed: 08/15/2011
• Published: 12/08/2011
• Est. Priority Date: 07/29/1996
• Status: Active Grant

• Current Assignee: Kensho Sakano, Toshio Moriguchi, Yasunobu Noguchi, Yoshinori Shimizu
• Original Assignee: Kensho Sakano, Toshio Moriguchi, Yasunobu Noguchi, Yoshinori Shimizu
• Inventors: Shimizu, Yoshinori, Sakano, Kensho, Noguchi, Yasunobu, Moriguchi, Toshio
• Granted Patent: US 8,685,762 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: C09K 11/7767 Chalcogenides
• CPC Class Codes: C09K 11/7774 Aluminates
• CPC Class Codes: G02B 6/0023 provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
• CPC Class Codes: G02B 6/0025 Diffusing sheet or layer; Prismatic sheet or layer
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]
• CPC Class Codes: H01J 29/20 characterised by the luminescent material
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/45147 Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/45169 Platinum (Pt) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• CPC Class Codes: H01L 2924/01021 : Scandium [Sc]
• CPC Class Codes: H01L 2924/01067 : Holmium [Ho]
• CPC Class Codes: H01L 2924/01068 : Erbium [Er]
• CPC Class Codes: H01L 2924/12036 : PN diode
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/15747 : Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/20751 : larger or equal to 10 microns less than 20 microns
• CPC Class Codes: H01L 2924/20752 : larger or equal to 20 microns less than 30 microns
• CPC Class Codes: H01L 2924/20753 : larger or equal to 30 microns less than 40 microns
• CPC Class Codes: H01L 2924/20754 : larger or equal to 40 microns less than 50 microns
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H01L 2933/0091 : Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/50 : Wavelength conversion elements
• CPC Class Codes: H01L 33/501 : characterised by the materials, e.g. binder
• CPC Class Codes: H01L 33/502 : Wavelength conversion materials
• CPC Class Codes: H01L 33/504 : Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/56 : Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H05B 33/14 : characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source
• CPC Class Codes: Y02B 20/00 : Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A light emitting device comprises: an LED chip having a quantum well structure and a light emitting layer made of a gallium nitride compound semiconductor; a first transparent material covering the LED chip; a second transparent material for protecting the LED chip and the first transparent material; and a phosphor for absorbing a part of the light from the LED chip and emitting a light having a wavelength different from the light from the LED chip; wherein the phosphor is included in second transparent material, and the light from the LED chip and the light from said phosphor are mixed to make a white light.

Claims

1. A light emitting device, comprising a light emitting component based on a nitride compound semiconductor and a phosphor capable of absorbing a part of the light emitted by the light emitting component and emitting light of a wavelength different from that of the absorbed light,

wherein a white color light is obtained by mixing a blue light emitted by the light emitting component and the light generated by the phosphor,

the chromaticity point (x, y) of the light generated by the phosphor satisfies

0.45≦

x≦

0.49 and 0.51≦

y≦

0.53, and

a peak wavelength of the blue light from the light emitting component is from 420 nm to 490 nm.

2. The light emitting device according to claim 1, wherein a peak wavelength of the blue light from the light emitting component is from about 450 nm to 475 nm.

3. The light emitting device according to claim 1, wherein an active layer of the semiconductor light emitting component comprises InGaN.

4. The light emitting device according to claim 1, wherein said phosphor has a crystal structure.

5. The light emitting device according to claim 1, wherein said phosphor comprises a phosphor having a garnet structure.

6. The light emitting device according to claim 1, wherein said phosphor has at least two different compositions.

7. The light emitting device according to claim 1, wherein said phosphor emits light of at least two different colors.

8. The light emitting device according to claim 1, wherein said phosphor emits light of at least two different wavelengths.

9. The light emitting device according to claim 1, wherein an emission peak of the phosphor is set within the range from about 510 nm to 600 nm.

10. The light emitting device according to claim 1, wherein an emission peak of the phosphor is set within the range from about 530 nm to 570 nm

11. A light emitting device, comprising a light emitting component based on a nitride compound semiconductor and a phosphor capable of absorbing a part of the light emitted by the light emitting component and emitting light of a wavelength different from that of the absorbed light,

wherein a white color light is obtained by mixing a blue light emitted by the light emitting component and the light generated by the phosphor, and

wherein a chromaticity point of the white light is on a straight line connecting a chromaticity point corresponding to a spectrum generated by the light emitting component and a chromaticity point corresponding to a spectrum generated by the phosphor,

and the chromaticity point of the white light is on a black body radiation locus in a chromaticity diagram.

12. The light emitting device according to claim 11, wherein a peak wavelength of the blue light from the light emitting component is from about 420 nm to 490 nm.

13. The light emitting device according to claim 11, wherein a peak wavelength of the blue light from the light emitting component is from about 450 nm to 475 nm.

14. The light emitting device according to claim 11, wherein an active layer of the semiconductor light emitting component comprises InGaN.

15. The light emitting device according to claim 11, wherein said phosphor has a crystal structure.

16. The light emitting device according to claim 11, wherein said phosphor comprises a phosphor having a garnet structure.

17. The light emitting device according to claim 11, wherein said phosphor comprises two different phosphors having different compositions.

18. The light emitting device according to claim 11, wherein an emission peak of the phosphor is set within the range from about 510 nm to 600 nm.

19. The light emitting device according to claim 11, wherein an emission peak of the phosphor is set within the range from about 530 nm to 570 nm.

20. A light emitting device, comprising a light emitting component based on a nitride compound semiconductor and a phosphor capable of absorbing a part of the light emitted by the light emitting component and emitting light of a wavelength different from that of the absorbed light,

wherein a white color light is obtained by mixing a blue light emitted by the light emitting component and the light generated by the phosphor, and

wherein the chromaticity point of the white light is on a black body radiation locus in a chromaticity diagram.