Lighting device, lighting control method, and display device

Patent metadata

Field	Value
Publication number	US-9734766-B2
Application number	US-201514804479-A
Country	US
Kind code	B2
Filing date	Jul 21, 2015
Priority date	Aug 28, 2014
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A lighting device includes a light source and a control section. The control section has a first mode and a second mode as luminance setting modes of the light source and sets, in order to exercise variable control of a reach time taken to change luminance of the light source to a determined value, the reach time on the basis of the first mode for a determined period at the time of switching from the first mode to the second mode.

First claim

What is claimed is:

1. A display device comprising:
a light source;
an image analysis section
which performs, at the time of calculating an expansion coefficient from a first image including signal values for a first subpixel, a second subpixel, and a third subpixel and at the time of generating a luminance control signal for controlling luminance of the light source in order to exercise variable control of a reach time taken to change the luminance of the light source to a determined value, a determined process on the expansion coefficient and the luminance control signal, and
which outputs the expansion coefficient and the luminance control signal;

an image signal generation section which generates a signal value for a fourth subpixel on the basis of the expansion coefficient after the determined process, which generates a second image including the signal values for the first subpixel, the second subpixel, the third subpixel, and the fourth subpixel, and which outputs the second image to a display side; and
a light source control section which generates, on the basis of the luminance control signal after the determined process, a drive signal for making the light source emit light and which supplies the drive signal to the light source,
wherein the image analysis section:
has a first mode and a second mode as luminance setting modes of the light source; and
sets, in order to exercise variable control of the reach time taken to change the luminance of the light source to the determined value, the reach time on the basis of the first mode for a determined period at the time of switching from the first mode to the second mode.

2. The display device according to claim 1 , wherein when a first reach time taken to change the luminance to the determined value is set in the first mode, the image analysis section sets the first reach time set in the first mode for the determined period at the time of switching from the first mode to the second mode.

3. The display device according to claim 1 , wherein the image analysis section:
sets the light source to a first luminance in the first mode; and
sets the light source to a second luminance lower than the first luminance in the second mode.

4. The display device according to claim 3 , wherein the image analysis section:
fixes the luminance of the light source in the first mode; and
changes the luminance of the light source on the basis of an image scene in the second mode.

5. The display device according to claim 1 , wherein the image analysis section sets plural reach times for the determined period by switching the plural reach times step-by-step.

6. A method of driving a display device comprising:
performing, by an image analysis section, at the time of calculating an expansion coefficient from a first image including signal values for a first subpixel, a second subpixel, and a third subpixel and at the time of generating a luminance control signal for controlling luminance of a light source in order to exercise variable control of a reach time taken to change the luminance of the light source to a determined value, a determined process on the expansion coefficient and the luminance control signal;
outputting, by the image analysis section, the expansion coefficient and the luminance control signal;
generating, by an image signal generation section, a signal value for a fourth subpixel on the basis of the expansion coefficient after the determined process, generating a second image including the signal values for the first subpixel, the second subpixel, the third subpixel, and the fourth subpixel, and outputting the second image to a display side; and
generating, by a light source control section, on the basis of the luminance control signal after the determined process, a drive signal for making the light source emit light and supplying the drive signal to the light source,
wherein the image analysis section:
has a first mode and a second mode as luminance setting modes of the light source; and
sets, in order to exercise variable control of the reach time taken to change the luminance of the light source to the determined value, the reach time on the basis of the first mode for a determined period at the time of switching from the first mode to the second mode.

7. A display device comprising:
a light source;
image analysis circuitry configured to perform, at the time of calculating an expansion coefficient from a first image including signal values for a first subpixel, a second subpixel, and a third subpixel and at the time of generating a luminance control signal for controlling luminance of the light source in order to exercise variable control of a reach time taken to change the luminance of the light source to a determined value, a determined process on the expansion coefficient and the luminance control signal, and configured to output the expansion coefficient and the luminance control signal;
image signal generation circuitry configured to generate a signal value for a fourth subpixel on the basis of the expansion coefficient after the determined process, configured to generate a second image including the signal values for the first subpixel, the second subpixel, the third subpixel, and the fourth subpixel, and configured to output the second image to a display side; and
light source control circuitry configured to generate, on the basis of the luminance control signal after the determined process, a drive signal for making the light source emit light and configured to supply the drive signal to the light source,
wherein the image analysis circuitry is configured to have a first mode and a second mode as luminance setting modes of the light source; and is configured to set, in order to exercise variable control of the reach time taken to change the luminance of the light source to the determined value, the reach time on the basis of the first mode for a determined period at the time of switching from the first mode to the second mode.

8. The display device according to claim 7 , wherein when a first reach time taken to change the luminance to the determined value is set in the first mode, the image analysis circuitry sets the first reach time set in the first mode for the determined period at the time of switching from the first mode to the second mode.

9. The display device according to claim 7 , wherein the image analysis circuitry is configured to set the light source to a first luminance in the first mode, and set the light source to a second luminance lower than the first luminance in the second mode.

10. The display device according to claim 9 , wherein the image analysis circuitry is configured to fix the luminance of the light source in the first mode, and change the luminance of the light source on the basis of an image scene in the second mode.

11. The display device according to claim 7 , wherein the image analysis circuitry is configured to set plural reach times for the determined period by switching the plural reach times step-by-step.

Assignees

• Japan Display Inc

Inventors

• Sakaigawa Akira
• Nagatsuma Toshiyuki

Classifications

• G09G2320/0653

  Controlling or limiting the speed of brightness adjustment of the illumination source · CPC title

• G09G3/3406 Primary

  Control of illumination source (illumination devices structurally associated with liquid crystal cells G02F1/1336) · CPC title

• G09G2320/02

  Improving the quality of display appearance · CPC title

• G09G2320/062

  Adjustment of illumination source parameters · CPC title