Light source device including a planar light source having a single, substantially continuous light emission area and display device incorporating the light source device

• US 20050146652A1
• Filed: 03/07/2005
• Published: 07/07/2005
• Est. Priority Date: 06/05/1998
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Yokoyama, Osamu, Shimoda, Tatsuya, Miyashita, Satoru
• Granted Patent: US 7,126,652 B2
• Time in Patent Office: Days
• US Class Current: 349/61
• CPC Class Codes: G02B 27/1033 having a single light modulator for all colour channels
• CPC Class Codes: G02B 27/1053 having a single light modulator for all colour channels
• CPC Class Codes: G02B 27/1066 for enhancing image performance, like resolution, pixel numbers, dual magnifications or dynamic range, by tiling, slicing or overlapping fields of view
• CPC Class Codes: G02B 27/144 using partially transparent surfaces without spectral selectivity G02B27/147 takes precedence
• CPC Class Codes: G02B 27/149 using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes
• 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 1/133622 Colour sequential illumination
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources

Abstract

A red light source comprising an array of LEDs 102R that emit light of a red color, a green light source comprising an array of LEDs 102G that emit light of a green color, and a blue light source comprising an array of LEDs 102B that emit light of a blue color are deployed about the periphery of a dichroic prism 101. A liquid crystal display element is illuminated by a light source device configured such that the light from the respective light sources is synthesized into white light by the dichroic prism, and projection type liquid crystal display devices and the like are configured.

Claims

1. A light source device, comprising:

a first light source for emitting a first light;

a second light source for emitting a second light;

a third light source for emitting a third;

light;

a first polarization converter for obtaining a first polarized light from the first light, the first polarization converter including a first polarizer through which the first polarized light is obtained and utilizing a first reflection light reflected by the first polarizer so as to obtain the first polarized light;

a first reflector disposed at the first light source;

a second polarization converter for obtaining a second polarized light from the second light, the second polarization converter including a second polarizer through which the second polarized light is obtained and utilizing a second reflection light reflected by the second polarizer so as to obtain the second polarized light;

a second reflector disposed at the second light source;

a third polarization converter for obtaining a third polarized light from the third light, the third polarization converter including a third polarizer through which the third polarized light is obtained and utilizing a third reflection light reflected by the third polarizer so as to obtain the third polarized light;

a third reflector disposed at the third light source; and

a color synthesizing optical system for synthesizing the first polarized light, the second polarized light and the third polarized light.

2. The light source device according to claim 1, the first color being a color in a region from orange to red, the second color being a color in a region from green to yellow-green, and the third color being a color in a blue region.

3. The light source device according to claim 1, the first, second and third light sources being light emitting diodes.

4. The light source device according to claim 3, a plurality of the light emitting diodes being deployed two-dimensionally in the first, second and third light sources, respectively.

5. The light source device according to claim 4, further comprising lenses deployed between the first, second and third light sources and the color synthesizing optical system.

6. The light source device according to claim 4, further comprising lens array elements deployed between the first, second and third light sources and the color synthesizing optical system.

7. The light source device according to claim 1, each of the first, second and third light sources being a planar light source.

8. The light source device according to claim 1, the first, second and third light sources being flat-panel fluorescent tubes.

9. The light source device according to claim 1, the first, second and third polarization converters being reflecting polarizing plates.

10. The light source device according to claim 1, the first, second and third light sources being flat-panel electroluminescent elements.

11. The light source device according to claim 10, the electroluminescent elements being organic electroluminescent elements having organic thin films as a light emitting layer.

12. The light source device according to claim 11, the organic electroluminescent elements comprising optical resonators in light emitting layer structures thereof.

13. The light source device according to claim 1, the first, second and third polarization converters comprising quarter-wave films and reflecting polarizing plates, the quarter-wave films being deployed on sides toward the first, second and third light sources, and the reflecting polarizing plates being deployed on side towards the color synthesizing optical system.

14. The light source device according to claim 1, the first, second and third light sources being lit simultaneously.

15. The light source device according to claim 1, the first, second and third light sources repeatedly being lit in order.

16. A display device, comprising:

a light modulating element; and

the light source device according to claim 1, light from the light source device being modulated in the light modulating element and light so modulated being magnified by a projection lens and displayed.

17. The display device according to claim 16, the light modulating element comprising a transmissive type liquid crystal element and the light source device being deployed opposite one face of the liquid crystal element, and images formed on the liquid crystal element being magnified by the projection lens and displayed.

18. The display device according to claim 17, color filters being formed in pixels configuring the liquid crystal display element.

19. The display device according to claim 16, the light modulating element being a reflecting type light modulating element and the light source device being deployed opposite reflecting surface of the light modulating element.

20. A display device, comprising:

a light modulating element; and

the light source device according to claim 1,

light from the light source device being modulated in the light modulating element,

light so modulated being magnified by a projection lens and displayed as an image,

the light modulating element forming, with time division, a first color component image, a second color component image and a third color component image,

the first light source in the light source device being lit during a time interval, the first color component image being formed,

the second light source in the light source device being lit next during the time interval, the second color component image being formed, and

the third light source in the light source device being lit next during the time interval, the third color component image being formed, and

a color image being displayed by sequential display of the first, second and third color components in the light modulating element, and by sequential lighting of the first, second and third light sources corresponding to those sequential displays.