Illumination device and liquid crystal display device

• US 8,111,371 B2
• Filed: 07/02/2008
• Issued: 02/07/2012
• Est. Priority Date: 07/27/2007
• 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: Suminoe, Shinji, Yamamoto, Tomohiko, Tomiyoshi, Akira, Inoue, Naoto
• Primary Examiner(s): WONG, ERIC K
• Application Number:
  US12/599,837
• Publication Number:
  US 20100271565A1
• Time in Patent Office: 1,315 Days
• Field of Search: 349/151, 349/161, 349/61, 349/69, 362/612, 362/294, 345 80- 82, 250/553
• US Class Current: 349/161
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: H05B 45/28 using temperature feedback
• CPC Class Codes: H05B 45/40 Details of LED load circuits
• CPC Class Codes: H05B 45/48 having LEDs organised in strings and incorporating parallel shunting devices

Abstract

An illumination device includes an LED package, an LED driver including an FET, and a thermistor disposed on a substrate. A plurality of such LED packages are disposed on the substrate such that a first area and a second area, each determined by vertices corresponding to LED packages, are defined on the substrate. The thermistor is disposed in the first area, and the FET is disposed in the second area, which is outside of the first area. The thermistor detects a temperature in the first area. Such a configuration allows the thermistor to detect, in accordance with the temperature in the area, the temperature of heat transferred from the LED packages, without being affected by heat generated by the FET. This makes it possible to efficiently make temperature corrections to stabilize color temperature and luminance.

Claims

1. An illumination device comprising:

a substrate;

a plurality of luminous bodies disposed on the substrate;

a driving section arranged to drive the plurality of luminous bodies; and

a temperature detecting section disposed in an area surrounded by the plurality of luminous bodies;

wherein

a plurality of polygonal areas determined by vertices corresponding to the luminous bodies are located on the substrate, the driving section and the temperature detecting section are disposed in different ones of the polygonal areas, and the temperature detecting section is arranged to detect a temperature of the substrate in the polygonal area in which the temperature detecting section is disposed.

2. The illumination device according to claim 1, wherein the polygonal area in which the driving section is disposed and the polygonal area in which the temperature detecting section is disposed are adjacent to each other.

3. The illumination device according to claim 1, wherein the temperature detecting section is disposed near a circumcenter of the polygonal area.

4. The illumination device according to claim 1, wherein the driving section includes a control circuit and an electric current control transistor, the electric current control transistor being disposed in the polygonal area in which the driving section is disposed.

5. The illumination device according to claim 1, wherein:

the luminous bodies and the temperature detecting section are disposed on one surface of the substrate; and

the driving section is disposed on a surface of the substrate opposite to the surface on which the luminous bodies and the temperature detecting section are disposed.

6. The illumination device according to claim 1, wherein a heat dissipation material is provided on a surface of the substrate opposite to a surface of the substrate on which the luminous bodies are disposed so as to be on a backside of an area on the substrate in which the luminous bodies are disposed.

7. A liquid crystal display device comprising the illumination device according to claim 1 as a backlight.