Light emitting device and display

• US 8,679,866 B2
• Filed: 11/16/2010
• Issued: 03/25/2014
• Est. Priority Date: 07/29/1996
• Status: Expired due to Fees

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Shimizu, Yoshinori, Sakano, Kensho, Noguchi, Yasunobu, Moriguchi, Toshio
• Primary Examiner(s): Garber, Charles
• Assistant Examiner(s): MUSTAPHA, ABDULFATTAH B
• Application Number:
  US12/947,470
• Publication Number:
  US 20110062864A1
• Time in Patent Office: 1,225 Days
• Field of Search: 438 21- 27, 257/98, 257/99, 257/E33.044, 257/E33.059, 349 69-105
• US Class Current: 438/21
• 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:

an LED chip having a quantum well structure and a light emitting layer made of a gallium nitride compound semiconductor, said LED chip emitting a light having a peak wavelength in a range from 420 nm to 490 nm;

a first transparent material covering said LED chip;

a second transparent material for protecting said LED chip and said first transparent material; and

a phosphor for absorbing a part of the light from said LED chip and emitting a light having a wavelength different from the light from said LED chip;

wherein said phosphor comprises a phosphor having a garnet structure and including cerium as an emission center, and

wherein said phosphor is included in second transparent material, and the light from said LED chip and the light from said phosphor are mixed to make a white light.

2. The light emitting device according to claim 1, wherein said second transparent material contains a dispersant.

3. The light emitting device according to claim 2, wherein said dispersant is selected from the group consisting of barium titanate, titanium oxide, aluminum oxide and silicon dioxide.

4. The light emitting device according to claim 1, wherein said second transparent material has a structure of multiple layers being laminated.

5. The light emitting device according to claim 1, wherein said second transparent material is selected from the group consisting of epoxy resin, urea resin, silicone resin and glass.

6. The light emitting device according to claim 1, wherein said white light has an incandescent lamp color.

7. The light emitting device according to claim 1, wherein said phosphor containing at least one element selected from Y, Gd and Sm and at least one element selected from Al and Ga.

8. The light emitting device according to claim 1, wherein said phosphor comprises two or more kinds of fluorescent materials.

9. The light emitting device according to claim 1, wherein said phosphor comprises a phosphor capable of emitting green light.

10. The light emitting device according to claim 1, wherein said phosphor comprises a second phosphor capable of emitting red light.

11. The light emitting device according to claim 9, wherein said phosphor comprises a second phosphor capable of emitting red light.

12. A light emitting device comprising:

an LED chip having a quantum well structure and a light emitting layer made of a gallium nitride compound semiconductor, said LED chip emitting a light having a peak wavelength in a range from 420 nm to 490 nm; and

a phosphor for absorbing a part of the light from said LED chip and emitting a light having a wavelength different from the light from said LED chip;

wherein said phosphor comprises a phosphor having a garnet structure and including cerium as an emission center, and the light from said LED chip and the light from said phosphor are mixed to make a white light.

13. The light emitting device according to claim 12, wherein said phosphor is formed in a sheet shape.

14. The light emitting device according to claim 13, wherein said phosphor is formed in a sheet shape with a resin.

15. The light emitting device according to claim 12, wherein said white light has an incandescent lamp color.

16. The light emitting device according to claim 12, wherein said phosphor containing at least one element selected from Y, Gd and Sm and at least one element selected from Al and Ga.

17. The light emitting device according to claim 12, wherein said phosphor comprises two or more kinds of fluorescent materials.