ILLUMINATION DEVICE AND DISPLAY DEVICE INCLUDING THE SAME

• US 20130038212A1
• Filed: 08/09/2012
• Published: 02/14/2013
• Est. Priority Date: 08/11/2011
• 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: Yabuta, Junko
• Granted Patent: US 8,982,165 B2
• Time in Patent Office: Days
• US Class Current: 315/113
• CPC Class Codes: G02F 1/133601 for spatial active dimming
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133611 including means for improving the brightness uniformity
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/24 using electrical feedback from LEDs or from LED modules

Abstract

An illumination device includes a light source in which a plurality of light emitting elements are arranged, a luminous intensity controller configured to control luminous intensities of the plurality of light emitting elements separately in groups of one or more light emitting elements, and a predetermined correction table indicating temperature distribution characteristics corresponding to position information of the plurality of light emitting elements in the light source. The luminous intensity controller controls the luminous intensities of the plurality of light emitting elements corresponding to the position information based on the temperature distribution characteristics of the correction table.

Claims

1. An illumination device comprising:

a light source in which a plurality of light emitting elements are arranged;

a luminous intensity controller configured to control luminous intensities of the plurality of light emitting elements separately in groups of one or more light emitting elements; and

a predetermined correction table indicating temperature distribution characteristics corresponding to position information of the plurality of light emitting elements in the light source,

wherein

the luminous intensity controller controls the luminous intensities of the plurality of light emitting elements corresponding to the position information in accordance with the temperature distribution characteristics of the correction table.

2. The illumination device according to claim 1, further comprising:

an orientation detector configured to detect an orientation of the illumination device,

wherein

the correction table is previously provided for each of a plurality of predetermined orientations of the illumination device, and

the luminous intensity controller selects one of the correction tables provided for the plurality of orientations of the illumination device based on detection data from the orientation detector, and controls the light intensities of the plurality of light emitting elements corresponding to the position information based on the temperature distribution characteristics of the selected correction table.

3. The illumination device according to claim 2, wherein

the orientation detector includes an angle detector configured to detect a first rotation angle between an X axis extending along a horizontal direction of the illumination device and a Z axis extending along a vertical direction perpendicular to the horizontal direction, and a second rotation angle between a Y axis extending along a horizontal direction perpendicular to the X axis of the illumination device and the Z axis.

4. The illumination device according to claim 1, wherein

the light source is a planar light source, and

the correction table indicates the temperature distribution characteristics in the planar light source corresponding to the position information of the plurality of light emitting elements in the planar light source.

5. The illumination device according to claim 4, further comprising:

a heat dissipation member provided at a portion of a back surface opposite to a light emitting surface of the planar light source.

6. The illumination device according to claim 5, wherein

the heat dissipation member is a metal member.

7. The illumination device according to claim 5, wherein

the heat dissipation member is a supporting frame configured to support the planar light source.

8. The illumination device according to claim 4, further comprising:

a cooling device provided at a portion of a back surface opposite to a light emitting surface of the planar light source.

9. The illumination device according to claim 1, wherein

the luminous intensity controller controls the luminous intensities of the plurality of light emitting elements based on temperature differences between temperature settings at positions corresponding to the plurality of light emitting elements in the temperature distribution characteristics of the correction table, and a reference temperature which is used as a reference for a luminous intensity control of controlling the luminous intensity.

10. The illumination device according to claim 9, wherein

the luminous intensity controller decreases the luminous intensities of any one or more of the plurality of light emitting elements that have characteristics indicating a negative correlation between the temperature and the luminous intensity and have a lower temperature setting than the reference temperature, by an amount corresponding to the temperature difference.

11. The illumination device according to claim 9, wherein

the luminous intensity controller increases the luminous intensities of any one or more of the plurality of light emitting elements that have characteristics indicating a negative correlation between the temperature and the luminous intensity and have a higher temperature setting than the reference temperature, by an amount corresponding to the temperature difference.

12. The illumination device according to claim 10, wherein

the reference temperature is a highest temperature setting in the temperature distribution characteristics.

13. The illumination device according to claim 1, further comprising:

a plurality of light emitting element groups each including the plurality of light emitting elements,

wherein

the plurality of light emitting elements in the plurality of light emitting element groups emit light having colors that differ among the plurality of light emitting element groups,

the light source emits light having a predetermined color by combining light beams of the plurality of light emitting elements in the plurality of light emitting element groups, and

the luminous intensity controller controls the luminous intensities of the plurality of light emitting elements in each of the plurality of light emitting element groups, separately in groups of one or more light emitting elements.

14. A display device comprising the illumination device according to claim 1.

15. The display device according to claim 14, wherein

a display image of the display device is divided into sub-regions, and the luminous intensity controller controls the luminous intensities of any one or more of the plurality of light emitting elements that correspond to each of the sub-regions based on a lightness or darkness of the each of the sub-regions.