Light source control device, illuminaton device, and liquid crystal display device

• US 7,839,091 B2
• Filed: 02/03/2006
• Issued: 11/23/2010
• Est. Priority Date: 08/12/2005
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Fujine, Toshiyuki, Kohashikawa, Seiji
• Primary Examiner(s): Owens; Douglas W
• Assistant Examiner(s): Le; Tung X
• Application Number:
  US12/063,575
• Publication Number:
  US 20090140656A1
• Time in Patent Office: 1,754 Days
• Field of Search: 315/151, 315/291, 315300-302, 315307-308, 315/363, 315/155, 315/157, 362221-225, 362/276, 362/800, 345 82- 84, 345/102, 345/204
• US Class Current: 315/151
• CPC Class Codes: G01J 1/0271 Housings; Attachments or accessories for photometers
• CPC Class Codes: G01J 1/04 Optical or mechanical part supplementary adjustable parts
• CPC Class Codes: G01J 1/0407 Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings
• CPC Class Codes: G01J 1/0422 using light concentrators, collectors or condensers
• CPC Class Codes: G01J 1/32 adapted for automatic variation of the measured or reference value regulation of light intensity G05D25/00
• CPC Class Codes: G01J 1/4228 arrangements with two or more detectors, e.g. for sensitivity compensation
• CPC Class Codes: G01J 2003/1213 Filters in general, e.g. dichroic, band
• CPC Class Codes: G01J 3/14 using refracting elements, e.g. prisms G01J3/18, G01J3/26 take precedence prisms per se G02B5/04
• CPC Class Codes: G02B 6/0063 for extracting light out both the major surfaces of the light guide
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02F 1/13318 Circuits comprising a photodetector
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133609 including means for improving the color mixing, e.g. white
• CPC Class Codes: H05B 35/00 Electric light sources using a combination of different types of light generation
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/22 using optical feedback
• CPC Class Codes: H05B 45/40 Details of LED load circuits
• CPC Class Codes: H05B 47/19 via wireless transmission

Abstract

A light emission device capable of holding a uniform color in various environments is provided. A light source control device has a light detection device for detecting emission brightness of light sources that emit different colors and controlling emission brightness of at least one light source of the light sources based on the detection result of the light detection device. A through-hole is formed in a reflection member for reflecting light emitted from the light source, and the reflection is in a predetermined direction. The light detection device is provided across the reflection member from the light source, and the light propagation member is provided at the through-hole.

Claims

1. A light source control device which includes a light detection device for detecting emission brightness of a plurality of light sources emitting different colors of light, and which controls emission brightness of at least one of the plurality of light sources on the basis of a detection result of the light detection device, the light source control device comprising:

a through hole that extends through a reflective member that reflects light emitted from the light source in a predetermined direction and a chassis in which the reflective member is provided; and

a light propagation member attached to the chassis and the reflective member and being inserted in the through hole, the light propagation member being made of a transparent material, such that light from the light source is propagated through the through hole,

wherein the light source is disposed at a first side of the chassis, and the light detection device is disposed at a second side of the chassis opposite to the first side.

2. The light source control device according to claim 1, wherein the light propagation member includes a convex portion, and the convex portion is fitted to the through hole.

3. The light source control device according to claim 1, wherein the light propagation member has a height higher than the light source.

4. The light source control device according to claim 1, wherein the light detection device detects light having been separated by light separating means after passing through the through hole.

5. The light source control device according to claim 1, further comprising:

a housing room for housing the light detection device on the second side of the chassis,

wherein light emitted from the light source is prevented from passing through the housing room.

6. The light source control device according to claim 1, wherein the reflective member and the chassis include a plurality of through holes.

7. The light source control device according to claim 6, further comprising:

opening and closing means that individually controls whether or not to input light to the light detection means, for respective light beams passing through the plurality of through holes.

8. The light source control device according to claim 6, further comprising:

transmission-wavelength selecting means that selects a transmission wavelength of light entering the light detection means, for respective light beams passing through the plurality of through holes.

9. The light source control device according to claim 6, further comprising:

a back-surface light guiding means that guides light having passed through the plurality of through holes to the light detection means, the back-surface light guiding means being provided on the second side of the chassis.

10. The light source control device according to claim 6, further comprising:

a housing room for housing the light detection device, the housing room having a size that covers an arrangement area of the plurality of through holes, the housing room being provided on the second side of the chassis,

wherein light emitted from the light source is prevented from passing through the housing room.

11. The light source control device according to claim 6, further comprising:

a plurality of light detection devices.

12. The light source control device according to claim 11, wherein light having passed through the plurality of through holes is detected by the plurality of light detection devices.

13. The light source control device according to claim 11, further comprising:

a plurality of housing rooms for respectively housing the plurality of light detection devices, the plurality of housing rooms being provided on the second side of the chassis,

wherein light emitted from the light source is prevented from passing through each of the housing rooms.

14. The light source control device according to claim 1, wherein

the light source includes an LED and a fluorescent lamp, while the light propagation member includes a base substrate and a plurality of holding parts, and

a positional relationship of the fluorescent lamp is maintained at a predetermined spacing by the plurality of holding parts.

15. An illumination device, comprising:

the light source control device according to claim 1.

16. A liquid crystal display device, comprising:

the illumination device according to claim 15; and

a liquid crystal panel.

17. A light source control device, comprising:

a plurality of light sources emitting different colors of light;

a light detection device for detecting emission brightness of the plurality of light sources, and for controlling emission brightness of at least one of the plurality of light sources on the basis of a detection result of the light detection device, the light source control device;

a chassis accommodating the plurality of light sources therein, the chassis having a through hole;

a reflective member provided in the chassis for reflecting light emitted by the plurality of light sources; and

a light propagation member attached to the chassis and being inserted in the through hole, the light propagation member being made of a transparent material, such that light from the plurality of light sources is propagated through the through hole,

wherein the light detection device is disposed outside the chassis, such that the light has passed through the light propagation member is received by the light detection device.