Lighting device, and liquid crystal display device using same

• US 7,690,805 B2
• Filed: 05/13/2005
• Issued: 04/06/2010
• Est. Priority Date: 05/19/2004
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Okita, Hiroyuki, Kubota, Shigeo, Kawashima, Toshitaka, Osako, Junichi
• Primary Examiner(s): Negron; Ismael
• Application Number:
  US11/569,147
• Publication Number:
  US 20080170178A1
• Time in Patent Office: 1,789 Days
• Field of Search: 362/97.3, 362/231, 362/241, 362/247, 362/249.02, 362/293, 257/82, 257/89, 257/98
• US Class Current: 362/97.3
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133609 including means for improving the color mixing, e.g. white

Abstract

There is provided a lighting device that lights a liquid crystal panel, including a substrate (51) on which red, green and blue light separating plates (52R, 52G, 52B) are alternately disposed with a pitch of w in array. Red LEDs (53R) are disposed one at every other center between the green and blue light separating plates (52G, 52B), green LEDs 53G are disposed one at every other center between the blue and red light separating plates (52B, 52R), and blue LEDs (53B) are disposed one at every other center between the red and green light separating plates (52R, 52G).

Claims

1. A lighting device comprising:

light emitting diodes (LED); and

light separating means for reflecting a part of light emitted from the light emitting diodes while transmitting a part of the light,

the light separating means transmitting a part of the light emitted from the light emitting diode while reflecting a part of the light to form, in a position symmetrical with the light emitting diode with respect to the light separating means, a virtual image of the light emitting diode which is an apparent source of the light having been reflected by the light separating means.

2. The lighting device according to claim 1, wherein the light separating means has a transmittance and reflectance corresponding to the intensity of light emitted from the light emitting diode that emits light for incidence upon the light separating means.

3. The lighting device according to claim 1, wherein the light emitting diodes include red light emitting diodes to emit red light, green light emitting diodes to emit green light and blue light emitting diodes to emit blue light.

4. The lighting device according to claim 3, where the light separating means includes red light separating means for transmitting a part of the red light while reflecting a part of the light and transmitting the green and blue light, green light separating means for transmitting a part of the green light while reflecting a part of the light and transmitting the blue and red light, and blue light separating means for transmitting a part of the blue light while reflecting a part of the light and transmitting the red and green light.

5. The lighting device according to claim 3, wherein the light separating means is a primary-colors light separating means for transmitting a part of the red, green and blue while reflecting a part of the light.

6. A lighting device comprising:

a plurality of light emitting diodes (LED) each having a high directivity in a direction skewed from the optical axis thereof; and

a plurality of light separating means for reflecting a part of light emitted from the light emitting diode while transmitting a part of the light,

the light separating means being disposed with a predetermined pitch in array, and the light emitting diodes are disposed one in every other area between the light separating means; and

the light separating means transmitting a part of the light emitted from the light emitting diode while reflecting a part of the light to form, in an area between the light separating means and where no light emitting diode is provided, a virtual image of the light emitting diode which is an apparent source of the light having been reflected by the light separating means.

7. The lighting device according to claim 6, wherein the light separating means has a transmittance and reflectance corresponding to the intensity of light emitted from the light emitting diode that emits light for incidence upon the light separating means.

8. The lighting device according to claim 6, wherein the light emitting diodes include red light emitting diodes to emit red light, green light emitting diodes to emit green light and blue light emitting diodes to emit blue light.

9. The lighting device according to claim 8, where the light separating means includes a red light separating means for transmitting a part of the red light while reflecting a part of the light and transmitting the green and blue light, a green light separating means for transmitting a part of the green light while reflecting a part of the light and transmitting the blue and red light, and a blue light separating means for transmitting a part of the blue light while reflecting a part of the light and transmitting the red and green light.

10. The lighting device according to claim 8, wherein the light separating means is a primary-colors light separating means for transmitting a part of the red, green and blue while reflecting a part of the light.

11. A liquid crystal display device including a transmission-type liquid crystal panel and a lighting device to light the liquid crystal panel from one main side of the latter, the lighting device comprising:

light emitting diodes (LED); and

light separating means for reflecting a part of light emitted from the light emitting diodes while transmitting a part of the light,

the light separating means transmitting a part of the light emitted from the light emitting diode while reflecting a part of the light to form, in a position symmetrical with the light emitting diode with respect to the light separating means, a virtual image of the light emitting diode which is an apparent source of the light having been reflected by the light separating means.

12. The lighting device according to claim 11, wherein the light separating means has a transmittance and reflectance corresponding to the intensity of light emitted from the light emitting diode that emits light for incidence upon the light separating means.

13. The lighting device according to claim 11, wherein the light emitting diodes include red light emitting diodes to emit red light, green light emitting diodes to emit green light and blue light emitting diodes to emit blue light.

14. The lighting device according to claim 13, wherein the light separating means includes red light separating means for transmitting a part of the red light while reflecting a part of the light and transmitting the green and blue light;

green light separating means for transmitting a part of the green light while reflecting a part of the light and transmitting the blue and red light; and

blue light separating means for transmitting a part of the blue light while reflecting a part of the light and transmitting the red and green light.

15. The lighting device according to claim 13, wherein the light separating means is a primary-colors light separating means for transmitting a part of the red, green and blue while reflecting a part of the light.