Light source device and display having the same

• US 20040124764A1
• Filed: 10/22/2003
• Published: 07/01/2004
• Est. Priority Date: 10/25/2002
• Status: Abandoned Application

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Fujitsu Display Technologies Corporation (Fujitsu Limited)
• Inventors: Hayashi, Keiji, Suzuki, Toshihiro, Hamada, Tetsuya, Kobayashi, Tetsuya, Sugawara, Mari
• Application Number:
  US10/691,461
• Publication Number:
  US 20040124764A1
• Time in Patent Office: Days
• US Class Current: 313/498
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02B 6/0043 provided on the surface of the light guide
• CPC Class Codes: G02B 6/0046 Tapered light guide, e.g. wedge-shaped light guide
• CPC Class Codes: G02B 6/0048 with stepwise taper
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side

Abstract

The invention relates to a light source device utilizing an array of discrete light sources and a display having the same and provides a small and thin light source device capable of achieving high display quality and a display having the same. A planar light guide plate is employed which has point light sources that emit light, a first light-emitting region provided in an area other than the neighborhood of one of the point light sources and having a first lighting element for taking out light guided from the side of the point light source, and a second light-emitting region provided in an area other than the neighborhood of the other point light source and having a second lighting element for taking out light guided from the side of the point light source.

Claims

1. A light source device comprising:

first and second light sources which emit light; and

a planar light guide plate having a first light-emitting region which is provided in an area other than the neighborhood of the first light source and which has a first lighting element for taking out light guided from the side of the first light source and a second light-emitting region which is provided in an area other than the neighborhood of the second light source and which has a second lighting element for taking out light guided from the side of the second light source.

2. A light source device according to claim 1, wherein the first and second lighting elements include a prism-like feature formed on a surface of the planar light guide plate.

3. A light source device according to claim 1, wherein the first and second lighting elements include a light-scattering element formed on a surface of the planar light guide plate.

4. A light source device according to claim 1, wherein the planar light guide plate has light-reflecting elements for reflecting light on end faces thereof which are opposite to the first and second light sources, respectively.

5. A light source device according to claim 1, wherein each of the first and second light sources is a plurality of point light sources which are provided side by side.

6. A light source device according to claim 1, wherein the first light source is provided near the second light-emitting region and wherein the second light source is provided near the first light-emitting region.

7. A light source device according to claim 1, further comprising:

a first light guide region for guiding light from the side of the first light source to the first light-emitting region; and

a second light guide region for guiding light from the side of the second light source to the second light-emitting region;

wherein the first and second light guide regions are provided in the single planar light guide plate.

8. A light source device according to claim 1, further comprising:

a first light guide region for guiding light from the side of the first light source to the first light-emitting region; and

a second light guide region for guiding light from the side of the second light source to the second light-emitting region;

wherein the first and second light guide regions are provided in each of a couple of the planar light guide plates which are stacked one on the other.

9. A light source device according to claim 1, further comprising a light source driving circuit for causing the first and second light sources to emit light at a predetermined flashing frequency at predetermined timing which is different between the light sources.

10. A light source device according to claim 1, wherein the first and second light-emitting regions are divided into respective plural parts which are alternately arranged.

11. A light source device according to claim 1, wherein the first and second lighting elements include a wedge-like feature of the planar light guide plate.

12. A light source device according to claim 1, wherein a plurality of the planar light guide plates are provided such that they are optically independent of each other.

13. A display comprising:

a display panel having a display area including a plurality of pixels;

a driving circuit for supplying a predetermined drive signal to the display panel; and

a light source device for illuminating the display panel;

wherein the light source device is a light source device according to claim 1.

14. A display according to claim 13, wherein the display panel is a liquid crystal display panel having a pair of substrates and a liquid crystal sealed between the pair of substrates.

15. A display according to claim 13, wherein the first and second light-emitting regions are arranged in a direction in which the display area is scanned.

16. A display according to claim 13, wherein the flashing frequency is equal to a frame frequency of the display panel.

17. A display according to claim 13, wherein the driving circuit performs multi-scan by supplying the driving signal to the display panel in synchronism with said timing.