Light emitting device with blue light led and phosphor components

• US 7,071,616 B2
• Filed: 07/01/2003
• Issued: 07/04/2006
• Est. Priority Date: 07/29/1996
• Status: Expired due to Fees

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Kagaku Kogyo Kabushiki Kaisha
• Inventors: Nakanishi, Eiji, Shimizu, Yoshinori, Moriguchi, Toshio, Sakano, Kensho, Noguchi, Yasunobu
• Primary Examiner(s): WILLIAMS, JOSEPH L
• Application Number:
  US10/609,503
• Publication Number:
  US 20040004437A1
• Time in Patent Office: 1,099 Days
• Field of Search: 313/504, 313/506, 313/512, 313/486, 313/489, 313/498, 313/501, 313/502, 313/503, 428/690
• US Class Current: 313/506
• 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 source having a planar main surface capable of emitting a white light includes a blue LED, an optical guide plate having a planar main surface and an edge face receiving injection of the light from the blue LED, and a coating material of transparent resin or glass containing fluorescent materials positioned between the blue LED and the optical guide plate. The fluorescent materials can be exited by absorption of a part of the blue light from the blue LED to emit fluorescent light and the fluorescent light can be mixed with a remaining part of the blue light to make white light in the optical guide plate.

Claims

1. A light source having a planar main surface capable of emitting a white light which comprises a blue LED, an optical guide plate having a planar main surface and an edge face getting injection of the light from said blue LED, and an coating material of transparent resin or glass containing fluorescent materials positioned between said blue LED and said optical guide plate, whereby the fluorescent materials can be excited by absorption of a part of the blue light from the blue LED to emit fluorescence light and the fluorescence light can be mixed with a remaining part of the blue light to make a white light in said optical guide plate.

2. A light source having a planar main surface of emitting a white light according to claim 1, wherein the coating material contains a fluorescent material capable of emitting a green fluorescence light and a fluorescent material capable of emitting a red fluorescence light.

3. A light source having a planar main surface of emitting a white light according to claim 1, wherein the coating material contains a fluorescent material capable of emitting a yellow fluorescence light.

4. A light source having a planar main surface of emitting a white light according to claim 1, wherein the coating material contains an inorganic fluorescent material.

5. A light source having a planar main surface of emitting a white light according to claim 1, wherein the transparent resin is selected from the group consisting of epoxy resin, urea resin and silicone.

6. A light source according to claim 1, wherein the light source is a back light source.

7. A light source according to claim 2, wherein the light source is a backlight source.

8. A light source according to claim 3, wherein the light source is a backlight source.

9. A light source according to claim 4, wherein the light source is a backlight source.

10. A light source according to claim 5, wherein the light source is a backlight source.

11. A liquid crystal display device arranged on a backlight source according to claim 6.

12. A light source having a planar main surface of emitting a white light according to claim 1, wherein the fluorescent material is a yellow body color which fluorescence light has complementary color relation with the light emitting from said blue LED.

13. A light source having a planar main surface of emitting a white light according to claim 1, wherein the fluorescent material comprises at least two different kinds of fluorescent materials.

14. A light source having a planar main surface of emitting a white light according to claim 13, wherein a first one of the fluorescent materials is capable of emitting a green fluorescence light and a second one of the fluorescent materials is capable of emitting a red fluorescence light.

15. A light source having a planar main surface of emitting a white light according to claim 1, wherein a dispersive sheet is arranged on said optical guide plate.