Light source device and display device

• US 8,770,773 B2
• Filed: 11/27/2008
• Issued: 07/08/2014
• Est. Priority Date: 12/07/2007
• Status: Active Grant

• Current Assignee: Sony Chemical & Information Device Corporation (Sony Group Corp.)
• Original Assignee: Dexerials Corporation
• Inventors: Yoshida, Tetsuyuki, Masuda, Shozo, Nada, Naoji, Ito, Yasushi, Tsukahara, Tsubasa
• Primary Examiner(s): Truong, Bao Q
• Application Number:
  US12/734,904
• Publication Number:
  US 20100315320A1
• Time in Patent Office: 2,049 Days
• Field of Search: 362/84, 362 971- 974, 362/230, 362/231, 362/235, 362/293, 362/330, 362/34, 362/311.02, 362/800
• US Class Current: 362/84
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses
• CPC Class Codes: G02F 1/133609 including means for improving the color mixing, e.g. white
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G02F 1/133617 Illumination with ultraviolet light; Luminescent elements or materials associated to the cell

Abstract

A light source device capable of suppressing generation of color unevenness, and a display device using the same are provided. The light source device 1 is provided with a plurality of excitation light sources 11 which are arranged at prescribed intervals D on a substrate 10 and emit blue light, and a phosphor layer 12 which converts part of the blue light emitted from the excitation light sources into red light and green light and arranged at a distance from the excitation light sources 11 to oppose the substrate 10. Fluctuation of intensity of each color light due to nonuniform application of the phosphor layer is difficult to occur as compared with a configuration in the past where the phosphor layer is formed adjacent to each excitation light source.

Claims

1. A light source device comprising:

a light emitting section to output color light in a first wavelength region;

a color conversion layer provided to be opposed to the light emitting section at a distance to convert a first part of the color light in the first wavelength region from the light emitting section into second color light in a second wavelength region, a wavelength of the second wavelength region being longer than that of the first wavelength region, and to output the second color light in the second wavelength region and to transmit a second part of the color light in the first wavelength region;

wherein the light emitting section has a plurality of point sources of light arranged at intervals on a substrate, and the color conversion layer extends over an entire region of the substrate where the plurality of point sources of light are arranged;

wherein the plurality of point sources of light are arranged on a plane, and the color conversion layer is arranged so as to be substantially parallel to the plane;

wherein a color conversion efficiency of the color conversion layer for exiting light with respect to incident light from the plurality of point sources of light is uniform independent of positions within a region corresponding to the plurality of point sources of light;

wherein an intensity of the first color light and the second color light output from the color conversion layer is uniform independent of an exit angle;

wherein a light path length within the color conversion layer of light passing through the color conversion layer is uniform independent of the exit angle; and

wherein a light exit surface of the color conversion layer in each region corresponding to each of the plurality of point sources of light is formed as a convex curved surface.

2. The light source device according to claim 1, wherein a light incident surface of the color conversion layer in each region corresponding to each of the plurality of point sources of light is formed as a concave curved surface, the convex curved surface, or a flat surface.

4. The light source device according to any one of claims 1 to 3, further comprising a transparent substrate which is in contact with the light incident surface of the color conversion layer to support the color conversion layer.

5. The light source device according to claim 1, further comprising a lens layer provided on a light incident surface side of the color conversion layer and refracting color light from each of the plurality of point sources of light to a direction in which the color lights are parallel one another.

6. The light source device according to claim 1, further comprising a lens layer,

wherein the light conversion layer in each region corresponding to each of the point sources of light has a curved surface shape which is concave on a light incident surface side and is formed to have a uniform thickness, and

the lens layer is provided on a light exit side of the color conversion layer along the curved surface shape of the color conversion layer and refracts the color light from each of the plurality of point sources of light in a direction in which the color lights are parallel one another.

7. The light source device according to claim 1, wherein the color conversion efficiency per unit-passage distance of light passing through the color conversion layer is different depending on positions within the region corresponding to the plurality of point sources of light.

8. The light source device according to claim 7, wherein concentration of a color conversion material in the color conversion layer is different depending on the positions within the region corresponding to each of the plurality of point sources of light.

9. The light source device according to claim 1, wherein

the light emitting section has a plurality of point sources of light arranged on a surface of a support, and

the color conversion layer is arranged along the surface of the support and is configured such that a central ray of light emitted from the plurality of point sources of light is incident vertically on a surface of the color conversion layer.

10. The light source device according to claim 9, wherein the plurality of point sources of light are arranged on a \ curved face, and

the color conversion layer is arranged along the curved face.

11. The light source device according to claim 9, wherein

the support has a rod-like shape, and

the color conversion layer is so arranged as to surround the light emitting section and has a tubular shape which is concentric to the support of the light emitting section.

12. The light source device according to claim 11, wherein a surface shape of the support and a surface shape of the color conversion layer are of a curved surface body.

13. The light source device according to claim 11, wherein a surface shape of the support and a surface shape of the color conversion layer are of a polyhedron.

14. The light source device according to claim 1, wherein the plurality of point sources of light comprise blue light emitting diodes emitting light in a blue (B:

Blue) wavelength region.

15. The light source device according to claim 14, wherein the color conversion layer converts the second part of the blue color light into a green color light in a green (G:

Green) wavelength region and into a red color light in a red (R;

Red) wavelength region, thereby to output a white light as a whole.

16. The light source device according to claim 1, wherein the color conversion layer comprises a phosphor material.

17. The light source device according to claim 1, further comprising a light diffusion layer provided on a light exit side of the color conversion layer.

3. A light source device comprising:

a light emitting section to output color light in a first wavelength region;

a color conversion layer provided to be opposed to the light emitting section at a distance to convert a first part of the color light in the first wavelength region from the light emitting section into second color light in a second wavelength region, a wavelength of the second wavelength region being longer than that of the first wavelength region, and to output the second color light in the second wavelength region and to transmit a second part of the color light in the first wavelength region;

wherein the light emitting section has a plurality of point sources of light arranged at intervals on a substrate, and the color conversion layer extends over an entire region of the substrate where the plurality of point sources of light are arranged;

wherein the plurality of point sources of light are arranged on a plane, and the color conversion layer is arranged so as to be substantially parallel to the plane;

wherein a color conversion efficiency of the color conversion layer for exiting light with respect to incident light from the plurality of point sources of light is uniform independent of positions within a region corresponding to the plurality of point sources of light;

wherein an intensity of the first color light and the second color light output from the color conversion layer is uniform independent of an exit angle;

wherein a light path length within the color conversion layer of light passing through the color conversion layer is uniform independent of the exit angle; and

wherein a light incident surface of the color conversion layer in each region corresponding to each of the point sources of light is formed as a convex curved surface.

21. The light source device according to claim 3, wherein the plurality of point sources of light comprise blue light emitting diodes emitting in a blue (B:

Blue) wavelength region.

22. The light source device according to claim 3, wherein the color conversion layer comprises a phosphor material.

23. The light source device according to claim 3, further comprising a light diffusion layer provided on a light exit side of the color conversion layer.

18. A display device comprising:

a display panel to be driven based on image data; and

a light source device to irradiate to irradiate light toward the display panel,

wherein the light source device includes;

a light emitting section to output color light in a first wavelength region; and

a color conversion layer provided to be opposed to the light emitting section at a distance, to convert a first part of the color light in the first wavelength region from the light emitting section into second color light in a second wavelength region, a wavelength of the second wavelength region being longer than that of the first wavelength region, and to output the second color light in the second wavelength region and to transmit a second part of the color light in the first wavelength region;

wherein the light emitting section has a plurality of point sources of light arranged at intervals on a substrate, and the color conversion layer extends over an entire region of the substrate where the plurality of point sources of light are arranged;

wherein the plurality of point sources of light are arranged on a plane, and the color conversion layer is arranged so as to be substantially parallel to the plane,

wherein a color conversion efficiency of the color conversion layer for exiting light with respect to incident light from the plurality of point sources of light is uniform independent of positions within a region corresponding to the plurality of point sources of light;

wherein an intensity of the first color light and the second color light output from the color conversion layer is uniform independent of an exit angle;

wherein a light path length within the color conversion layer of light passing through the color conversion layer is uniform independent of the exit angle; and

wherein a light exit surface of the color conversion layer in each region corresponding to each of the plurality of point sources of light is formed as convex curved surface.

19. The display device according to claim 18, wherein

the light emitting section has a plurality of point sources of light arranged on a plane, and

the color conversion layer is arranged so as to be substantially parallel to the plane.

20. The display device according to claim 19, wherein a color conversion efficiency of the color conversion layer for exiting light with respect to incident light from the point sources of light is uniform independent of positions within a region corresponding to the plurality of point sources of light.

24. A display device comprising:

a display panel to be driven based on image data; and

a light source device irradiating to irradiate light toward the display panel, wherein the light source device includes;

a light emitting section to output color light in a first wavelength region; and

a color conversion layer provided to be opposed to the light emitting section at a distance, to convert a first part of the color light in the first wavelength region from the light emitting section into second color light in a second wavelength region, a wavelength of the second wavelength region being longer than that of the first wavelength region, and to output the second color light in the second wavelength region and to transmit a second part of the color light in the first wavelength region,

wherein the light emitting section has a plurality of point sources of light arranged at intervals on a substrate, and the color conversion layer extends over an entire region of the substrate where the plurality of point sources of light are arranged,

wherein the plurality of point sources of light are arranged on a plane, and the color conversion layer is arranged so as to be substantially parallel to the plane,

wherein a color conversion efficiency of the color conversion layer for exiting light with respect to incident light from the plurality of point sources of light is uniform independent of positions within a region corresponding to the plurality of point sources of light,

wherein an intensity of the first color light and the second color light output from the color conversion layer is uniform independent of an exit angle,

wherein a light path length within the color conversion layer of light passing through the color conversion layer is uniform independent of the exit angle, and

wherein a light incident surface of the color conversion layer in each region corresponding to each of the point sources of light is formed as a convex curved surface.

25. The display device according to claim 24, wherein the light emitting section has a plurality of point sources of light arranged on a plane, and the color conversion layer is arranged so as to be substantially parallel to the plane.

26. The display device according to claim 25, wherein a color conversion efficiency of the color conversion layer for exiting light with respect to incident light from the point sources of light is uniform independent of positions within a region corresponding to the plurality of point sources of light.