Illumination device, display device, data generation method, non-transitory computer readable recording medium including data generation program for generating light amount adjustment data based on temperature

• US 9,324,279 B2
• Filed: 11/11/2010
• Issued: 04/26/2016
• Est. Priority Date: 02/24/2010
• 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
• Primary Examiner(s): Lubit, Ryan A
• Application Number:
  US13/576,665
• Publication Number:
  US 20120306942A1
• Time in Patent Office: 1,993 Days
• Field of Search: 345 82-107, 345/204, 345211-212, 345/214, 345690-691
• US Class Current: 1/1
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 2320/062 Adjustment of illumination source parameters
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/12 using optical feedback
• CPC Class Codes: H05B 45/18 using temperature feedback
• CPC Class Codes: H05B 45/20 Controlling the colour of the light

Abstract

A micon unit (11) performs, along at least one direction within the plane of planar light, brightness correction processing for adjusting brightness distribution of the planar light on light source color video signals (RSd, Gsd and BSd) so as to change them into light source color video signals (RSd′, GSd′ and BSd′), and the micon unit (11) further calculates the total light emission power of all LEDs (52) based on the light source color video signals (RSd′, GSd′ and BSd′), and performs, when the total light emission power exceeds an allowable light emission power, light emission power correction processing on the light source color video signals (RSd′, GSd′ and BSd′).

Claims

1. An illumination device comprising:

a plurality of light sources which are arranged in a plane and in a matrix arrangement and which emit light according to light amount adjustment data to form planar light;

a controller configured or programmed to perform correction processing on light source control data based on image data to generate the light amount adjustment data; and

a plurality of temperature sensors which measure a temperature of the plurality of light sources, each of the plurality of temperature sensors being arranged in a same horizontal plane as the plurality of light sources and at a center of a region surrounded by four of the plurality of light sources, the plurality of temperature sensors being evenly distributed among the matrix arrangement of the plurality of light sources such that each of the plurality of light sources is adjacent to only one of the plurality of temperature sensors, wherein

based on a measurement by the temperature measurement sensors, the controller is configured or programmed to correct variations in brightness of the plurality of light sources resulting from a temperature of the plurality of light sources on the light source control data,

the controller is configured or programmed to perform, along both an X axis direction and a Y axis direction within a plane of the planar light, brightness correction processing to adjust brightness distribution of the planar light on the light source control data on which the variations in brightness of the plurality of light sources resulting from the temperature of the plurality of light sources have been corrected so as to generate intermediate light source control data,

the controller further is configured or programmed to calculate a total light emission power of all the light sources based on the intermediate light source control data, and perform, when the total light emission power exceeds an allowable light emission power, light emission power correction processing to adjust the total light emission power within the allowable light emission power on the intermediate light source control data so as to generate the light amount adjustment data.

2. The illumination device of claim 1,

wherein, in the brightness correction processing, in each of the directions, a brightness around both ends in the direction is set lower than a brightness around a center.

3. The illumination device of claim 1,

wherein, in the brightness correction processing, brightness correction processing having a plurality of levels using different filters according to the measurement by the temperature sensors is set stepwise, and the controller is configured or programmed to perform the brightness correction processing in the set stepwise order.

4. The illumination device of claim 1,

wherein the controller is configured or programmed to calculate, for the total light emission power, a rate of limitation that is a scaling factor of the allowable light emission power, and multiply the intermediate light source control data on each of the light sources by the rate of limitation to generate the light amount adjustment data.

5. The illumination device of claim 1,

wherein the light emission power correction processing is a final type of processing among types of processing performed by the controller on the light source control data.

6. The illumination device of claim 1,

wherein the controller is configured or programmed to determine, based on a maximum value of the image data, the light source control data on each of the light sources.

7. The illumination device of claim 4,

wherein each of the light sources includes light emitting chips of a plurality of colors, and generates white light by mixture of light, and

when, in the light emission power correction processing, the controller is configured or programmed to:

calculate the total light emission power, calculate a light emission power for individual light emission colors, calculate the total light emission power from a total sum of the light emission power and multiply the light emission power for the individual light emission colors by the same rate of limitation to generate the light amount adjustment data.

8. The illumination device of claim 1,

wherein each of the light sources includes light emitting chips of a plurality of colors, and generates white light by mixture of light, and

the controller is configured or programmed to perform a different type of the brightness correction processing for each of the colors.

9. The illumination device of claim 1,

wherein the light sources are light sources of a single color, and

the controller is configured or programmed to perform the brightness correction processing corresponding to the signal color.

10. A display device comprising:

the backlight unit of claim 1; and

a liquid crystal display panel which displays an image according to the image data.

11. A data generation method of generating, in an illumination device, light amount adjustment data for controlling light emission of a plurality of light sources that are arranged in a plane and in a matrix arrangement to form planar light,

wherein, when correction processing is performed on light source control data based on image data to generate the light amount adjustment data,

variations in brightness of the plurality of light sources resulting from a temperature of the plurality of light sources are corrected on the light source control data, and along both an X axis direction and a Y axis direction within a plane of the planar light, brightness correction processing for adjusting brightness distribution of the planar light is performed on the light source control data on which the variations in brightness of the plurality of light sources resulting from the temperature of the plurality of light sources have been corrected so as to generate intermediate light source control data,

the temperature being measured by a plurality of temperature sensors, each of the plurality of temperature sensors being arranged in a same horizontal plane as the plurality of light sources and at a center of a region surrounded by four of the plurality of light sources, the plurality of temperature sensors being evenly distributed among the matrix arrangement of the plurality of light sources such that each of the plurality of light sources is adjacent to only one of the plurality of temperature sensors, and

based on the intermediate light source control data, a total light emission power of all the light sources is further calculated, and, when the total light emission power exceeds an allowable light emission power, light emission power correction processing for adjusting the total light emission power within the allowable light emission power is performed on the intermediate light source control data so as to generate the light amount adjustment data.

12. A non-transitory computer-readable recording medium including a data generation program for generating light amount adjustment data for use in an illumination device, wherein the illumination device includes a plurality of light sources which are arranged in a plane and in a matrix arrangement and which emit light according to the light amount adjustment data to form planar light and a controller configured or programmed to perform correction processing on light source control data based on image data to generate the light amount adjustment data, and

the data generation program instructs the controller to perform a method comprising:

correcting variations in brightness of the plurality of light sources resulting from a temperature of the plurality of light sources on light source control data, the temperature being measured by a plurality of temperature sensors, each of the plurality of temperature measurement sensors being arranged in a same horizontal plane as the plurality of light sources and at a center of a region surrounded by four of the plurality of light sources, the plurality of temperature sensors being evenly distributed among the matrix arrangement of the plurality of light sources such that each of the plurality of light sources is adjacent to only one of the plurality of temperature sensors,

performing, along both an X axis direction and a Y axis direction within a plane of the planar light, brightness correction processing for adjusting brightness distribution of the planar light on the light source control data on which the variations in brightness of the plurality of light sources resulting from the temperature of the plurality of light sources have been corrected so as to generate intermediate light source control data, and

calculating a total light emission power of all the light sources based on the intermediate light source control data, and performing, when the total light emission power exceeds an allowable light emission power, light emission power correction processing for adjusting the total light emission power within the allowable light emission power on the intermediate light source control data so as to generate the light amount adjustment data.