Illuminating device and display device including the same

• US 20060289880A1
• Filed: 05/24/2006
• Published: 12/28/2006
• Est. Priority Date: 06/28/2005
• Status: Active Grant

• Current Assignee: Hickory IP LLC (IP Edge LLC)
• Original Assignee: Seiko Instruments Incorporated (Seiko Group)
• Inventors: Kurihara, Makoto
• Granted Patent: US 7,476,016 B2
• Time in Patent Office: Days
• US Class Current: 257/89
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48464 the other connecting portion not on the bonding area also being a ball bond, i.e. ball-to-ball
• 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 2924/00014 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 33/501 characterised by the materials, e.g. binder
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/40 Details of LED load circuits

Abstract

Provided is a display device including: a light guide member for mixing light from a blue LED element coated with a translucent resin mixed with phosphor particles which converts blue light into green light with light from a red LED element to make white light exit from a light exit surface; and a non-self light emission display element provided on an irradiating surface side of the light guide member. Therefore, the display element is irradiated with white light whose sufficient wavelength region is 600 nm or more and whose intensity efficiency is high. When the display device further includes a circuit for separately controlling light emission intensities of the red LED element and a blue LED element, chromatic balance can be adjusted even after manufacturing and an intensity of the display device and color reproducibility thereof can be easily set in an optimum range even after assembly.

Claims

1. A display device comprising:

a blue-green light emitting diode package including a blue LED element to which a resin into which phosphor particles are dispersed is potted;

a red light emitting diode package including a red LED element;

a circuit board on which the red light emitting diode package and the blue-green light emitting diode package are separately arranged;

a light guide member opposed to the circuit board, for mixing blue-green light from the blue-green light emitting diode package with red light from the red light emitting diode package to make white light exit from a light exit surface of the light guide member; and

a display element of a non-self light emission type provided on a light exit surface side of the light guide member.

2. A display device according to claim 1, further comprising a circuit for controlling light emission intensities of the red LED element and the blue LED element.

3. A display device according to claim 2, wherein the display element comprises a liquid crystal panel including a color filter.

4. A display device according to claim 2, wherein:

the circuit for controlling the light emission intensities comprises a driver circuit for the red LED element and a driver circuit for the blue LED element;

the driver circuit for the red LED element includes a temperature-sensitive resistor; and

the driver circuit for the blue LED element includes a current detecting resistor.

5. A display device according to claim 2, wherein the display element comprises a liquid crystal panel including a color filter, and wherein the circuit controls light emission intensities of the red LED element and the blue LED element according to color balance of the color filter so that the display device can get preferable white balance.

6. A display device according to claim 4, wherein:

the blue LED element is made of a material of one of InGaN and GaN;

the red LED element is made of a material selected from the group consisting of GaP, GaAlAs, and AlGaInP; and

the phosphor particles comprise at least one selected from the group consisting of SrGa₂S₄;

Eu, Ca₃Sc₂Si₃O₁₂;

Ce, and Sr-SION;

Eu.

7. A display device according to claim 6, wherein the resin is a non-permeable material.

8. A display device according to claim 7, wherein the non-permeable material comprises at least one selected from the group consisting of silicon resin, cycloolefin resin, fluorine resin, and epoxy resin.

9. A display device comprising:

a blue LED element for emitting a blue light;

a phosphor for converting the blue light into a green light having a peek wavelength in a green spectral region;

a red LED element for emitting a red light;

a display element of a non-self light emission type having a color filter, the display element is illuminated by the blue light, the green light and the red light; and

a circuit for controlling light emission intensities of the red LED element and the blue LED element according to color balance of the color filter so that the display device can get preferable white balance.

10. An illuminating device comprising:

a blue-green light emitting- diode package including a blue LED element to which a resin into which phosphor particles are dispersed is potted;

a circuit board on which the red light emitting diode package including a red LED element and the blue-green light emitting diode package are separately arranged; and

a light guide member opposite and adjacent to the circuit board,

wherein blue-green light and red light are mixed in the light guide member to obtain white light.

11. An illuminating device according to claim 10, wherein the blue LED element is made of a material of one of InGaN and GaN.

12. An illuminating device according to claim 10, wherein the phosphor particles comprise at least one selected from the group consisting of SrGa₂S₄:

Eu, Ca₃Sc₂Si₃O₂;

Ce, and Sr-SION;

Eu.

13. An illuminating device according to claim 10, wherein the red LED element is made of a material selected from the group consisting of GaP, GaAlAs, and AlGaInP.

14. An illuminating device according to claim 10, wherein the resin comprises a non-permeable material.

15. An illuminating device according to claim 10, wherein the non-permeable material comprises at least one selected from the group consisting of silicon resin, cycloolefin resin, fluorine resin, and epoxy resin.