ILLUMINATING APPARATUS AND DISPLAY APPARATUS

• US 20120139445A1
• Filed: 03/15/2010
• Published: 06/07/2012
• Est. Priority Date: 08/31/2009
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: FUJIWARA, Kohji, MURAI, Takayuki, LEW, Kingfoong
• Granted Patent: US 9,122,094 B2
• Time in Patent Office: Days
• US Class Current: 315/294
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133613 characterized by the sequence of light sources

Abstract

Provided is a backlight unit (49) which includes a plurality of LEDs (11). The LEDs (11) are two-dimensionally disposed, thereby having the collection of light emitted from the LEDs (11) in a state of planar light. Furthermore, the backlight unit (49) has the planar light divided into a plurality of sections, and includes a luminance variable system (for instance, a system having disposition which a difference in the density of LEDs (11)), which can change luminance, corresponding to each section.

Claims

1. An illuminating apparatus including a plurality of point light sources, wherein

the plurality of point light sources are arranged two-dimensionally so that light therefrom gathers to form planar light,

the planar light is divided into a plurality of sections, and the illuminating apparatus includes a luminance-varying system that can vary luminance section by section.

2. The illuminating apparatus according to claim 1, wherein the luminance-varying system is an arrangement involving a difference in density of the point light sources.

3. The illuminating apparatus according to claim 2, wherein

when, of two intersecting directions, one is referred to as an X direction and another is referred to as a Y direction,

the illuminating apparatus includes point light sources arranged side by side along the X and Y directions, and

there are a plurality of kinds of intervals among intervals between the point light sources arranged side by side along at least one of the X and Y directions.

4. The illuminating apparatus according to claim 3, wherein

X-direction rows in which the point light sources are arranged at same positions with respect to the Y direction and side by side along the X direction are arranged side by side in the Y direction so that the plurality of point light sources are in a lattice-like planar arrangement.

5. The illuminating apparatus according to claim 4, wherein positions of the point light sources with respect to the X direction between adjacent X-direction rows are same from one X-direction row to the next.

6. The illuminating apparatus according to claim 4, wherein positions of the point light sources with respect to the X direction between adjacent X-direction rows differ from one X-direction row to the next.

7. The illuminating apparatus according to claim 5, wherein

when rows which are formed as a result of the X-direction rows being arranged side by side in the Y direction and in which the point light sources are arranged at same positions with respect to the X direction and side by side along the Y direction are referred to as Y-direction rows,

the illuminating apparatus further includes a point light source that is not along either the X-direction rows or the Y-direction rows.

8. The illuminating apparatus according to claim 3, wherein

one row of the point light sources arranged side by side along the X direction and one row of the point light sources arranged side by side along the Y direction emit light in different directions, and the light overlaps to form the planar light.

9. The illuminating apparatus according to claim 2, wherein

an interval at which a plurality of the point light sources that produce light near a planar center of the planar light are arranged is shorter than an interval at which a plurality of the point light sources that produce light at periphery elsewhere than near the planar center of the planar light are arranged.

10. The illuminating apparatus according to claim 2, wherein

an interval at which a plurality of the point light sources that produce light near a planar center of the planar light are arranged is longer than an interval at which a plurality of the point light sources that produce light at periphery elsewhere than near the planar center of the planar light are arranged.

11. The illuminating apparatus according to claim 2, wherein

the plurality of point light sources are in a planar arrangement, an arrangement surface of the planar arrangement includes a plurality of divided regions divided like a lattice, and

there are a plurality of kinds of numbers among numbers of point light sources located within the divided regions respectively.

12. The illuminating apparatus according to claim 11, wherein

when divided regions in which the point light sources that produce light near the planar center of the planar light are located are referred to as central divided regions, and

divided regions in which the point light sources that produce light at periphery elsewhere than near the planar center of the planar light are located are referred to as peripheral divided regions, then

a number of point light sources included in the central divided regions is greater than a number of point light sources included in the peripheral divided regions.

13. The illuminating apparatus according to claim 11, wherein

when divided regions in which the point light sources that produce light near the planar center of the planar light are located are referred to as central divided regions, and

divided regions in which the point light sources that produce light at periphery elsewhere than near the planar center of the planar light are located are referred to as peripheral divided regions, then

a number of point light sources included in the peripheral divided regions is greater than a number of point light sources included in the central divided regions.

14. The illuminating apparatus according to claim 2, wherein

a plurality of mounting boards on which the point light sources are mounted are arranged, and

whereas intervals at which the point light sources are arranged within each of the mounting boards are equal, the intervals at which the point light sources are arranged differ among the mounting boards.

15. The illuminating apparatus according to claim 2, wherein

a plane of the planar light is divided into a plurality of areas by an imaginary line lying on a planar center of the planar light, and an arrangement of a plurality of the point light sources that produce light of the planar light in one of the divided areas and an arrangement of a plurality of the point light sources that produce light of the planar light in another of the divided areas are line-symmetric about the imaginary line.

16. The illuminating apparatus according to claim 2, wherein

the illuminating apparatus includes a current controller that controls current values supplied to the point light sources, and

in a case where the point light sources are arranged some at a longer interval and other at a shorter interval,

the current controller makes different a current value supplied to the point light sources arranged at a longer interval and a current value supplied to the point light sources arranged at a shorter interval.

17. The illuminating apparatus according to claim 16, wherein current supplied to the point light sources arranged at a longer interval is higher than current supplied to the point light sources arranged at a shorter interval.

18. The illuminating apparatus according to claim 2, wherein

the point light sources are arranged some at a longer interval and other at a shorter interval, and

light emission efficiency of the point light sources differs between the point light sources arranged at a longer interval and the point light sources arranged at a shorter interval.

19. The illuminating apparatus according to claim 18, wherein

light emission efficiency of the point light sources arranged at a longer interval is higher than light emission efficiency of the point light sources arranged at a shorter interval.

20. The illuminating apparatus according to claim 1, wherein

the luminance-varying system is a current controller that varies the luminance by a difference in current values supplied to the point light sources.

21. The illuminating apparatus according to claim 1, wherein

to vary the luminance, the luminance-varying system has point light sources with different light emission efficiency included in the point light sources that produce the planar light.

22. A display apparatus comprising:

an illuminating apparatus according to claim 1; and

a display panel that receives light emanating from the illuminating apparatus.