Method for driving liquid crystal display device

• US 9,280,937 B2
• Filed: 12/24/2014
• Issued: 03/08/2016
• Est. Priority Date: 12/19/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kimura, Hajime
• Primary Examiner(s): LEE, NICHOLAS J
• Application Number:
  US14/582,244
• Publication Number:
  US 20150154918A1
• Time in Patent Office: 440 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G02F 1/133608 including particular frames or supporting means
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2310/0229 De-interlacing
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 2320/062 Adjustment of illumination source parameters
• 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 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 2340/0435 Change or adaptation of the frame rate of the video stream
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: G09G 3/36 using liquid crystals
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3655 Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors
• CPC Class Codes: H04N 5/142 Edging; Contouring
• CPC Class Codes: H04N 7/0117 involving conversion of the spatial resolution of the incoming video signal for graphics images G09G2340/0407
• CPC Class Codes: H04N 7/0125 one of the standards being a high definition standard

Abstract

A low-resolution image is displayed at high resolution and power consumption is reduced. Resolution is made higher by super-resolution processing. Then, display is performed with the luminance of a backlight controlled by local dimming after the super-resolution processing. By controlling the luminance of the backlight, power consumption can be reduced. Further, by performing the local dimming after the super-resolution processing, accurate display can be performed.

Claims

1. An electronic device, comprising:

a backlight comprising a first light source, a second light source, a first light guide plate, a second light guide plate and a light diffusing plate;

a light modulation device; and

a circuit,

wherein the first light source is placed along with a first surface of the first light guide plate;

wherein the second light source is placed along with a first surface of the second light guide plate;

wherein a second surface of the first light guide plate is placed so as to face a first surface of the light diffusing plate;

wherein a second surface of the second light guide plate is placed so as to face the first surface of the light diffusing plate;

wherein a surface of the light modulation device is placed so as to face a second surface of the light diffusing plate,

wherein each light intensity of a first area where the light modulation device is overlapped with the second surface of the first light guide plate and a second area where the light modulation device is overlapped with the second surface of the second light guide plate is independently controllable,

wherein the circuit is configured to form signals for a local dimming processing and to provide the signals to the backlight and the light modulation device, and

wherein the backlight and the light modulation device is configured to perform the local dimming processing by using the signals.

2. The electronic device according to claim 1,

wherein the light modulation device comprises a pair of electrodes and liquid crystal therebetween.

3. The electronic device according to claim 1,

wherein the first light guide plate is a triangular prism comprising a first side surface, a second side surface and a third side surface,

wherein the first light source is placed along with the first side surface,

wherein the second side surface is placed so as to be parallel to the first surface of the light diffusing plate, and

wherein an area of the first side surface of the first light guide plate is the smallest among the first side surface, the second side surface and the third side surface.

4. The electronic device according to claim 1,

wherein the circuit is configured to form first signals by a super resolution processing from original image signals,

wherein the circuit is configured to form second signals by an edge enhancement processing from the first signals, and

wherein the circuit is configured to form the signals for the local dimming processing from the second signals.

5. The electronic device according to claim 1,

wherein the first light source comprises a point light source.

6. The electronic device according to claim 1,

wherein the first light source comprises of a plurality of point light sources arranged in a line.

7. An electronic device, comprising:

a backlight comprising a first light source, a second light source, a first light guide plate, a second light guide plate and a light diffusing plate;

a light modulation device; and

a circuit,

wherein the first light source is placed along with a first surface of the first light guide plate;

wherein the second light source is placed along with a first surface of the second light guide plate;

wherein a second surface of the first light guide plate is placed so as to face a first surface of the light diffusing plate;

wherein a second surface of the second light guide plate is placed so as to face the first surface of the light diffusing plate;

wherein a surface of the light modulation device is placed so as to face a second surface of the light diffusing plate,

wherein each light intensity of a first area where the light modulation device is overlapped with the second surface of the first light guide plate and a second area where the light modulation device is overlapped with the second surface of the second light guide plate is independently controllable,

wherein the circuit is configured to form signals for a local dimming processing and a second processing selected from the group consisting of a super resolution processing, an edge enhancement processing and a frame interpolation processing, and to provide the signals to the backlight and the light modulation device, and

wherein the backlight and the light modulation device is configured to perform the local dimming processing by using the signals.

8. The electronic device according to claim 7,

wherein the light modulation device comprises a pair of electrodes and liquid crystal therebetween.

9. The electronic device according to claim 7,

wherein the first light guide plate is a triangular prism comprising a first side surface, a second side surface and a third side surface,

wherein the first light source is placed along with the first side surface,

wherein the second side surface is placed so as to be parallel to the first surface of the light diffusing plate, and

wherein an area of the first side surface of the first light guide plate is the smallest among the first side surface, the second side surface and the third side surface.

10. The electronic device according to claim 7,

wherein the circuit is configured to form first signals by the super resolution processing from original image signals,

wherein the circuit is configured to form second signals by the edge enhancement processing from the first signals, and

wherein the circuit is configured to form the signals for the local dimming processing from the second signals.

11. The electronic device according to claim 7,

wherein the first light source comprises a point light source.

12. The electronic device according to claim 7,

wherein the first light source comprises of a plurality of point light sources arranged in a line.

13. An electronic device, comprising:

a backlight comprising a first light source, a second light source, a light guide plate, and a light diffusing plate;

a light modulation device; and

a circuit,

wherein the first light source is placed along with a first surface of the light guide plate;

wherein a second surface of the light guide plate is placed so as to face a first surface of the light diffusing plate;

wherein a surface of the light modulation device is placed so as to face a second surface of the light diffusing plate,

wherein each light intensity of the first light source and the second light source is independently controllable,

wherein the circuit is configured to form signals for a local dimming processing and to provide the signals to the backlight and the light modulation device, and

wherein the backlight and the light modulation device is configured to perform the local dimming processing by using the signals.

14. The electronic device according to claim 13,

wherein the light modulation device comprises a pair of electrodes and liquid crystal therebetween.

15. The electronic device according to claim 13,

wherein the light guide plate is a triangular prism comprising a first side surface, a second side surface and a third side surface,

wherein the first light source is placed along with the first side surface,

wherein the second side surface is placed so as to be parallel to the first surface of the light diffusing plate, and

wherein an area of the first side surface of the light guide plate is the smallest among the first side surface, the second side surface and the third side surface.

16. The electronic device according to claim 13,

wherein the circuit is configured to form first signals by a super resolution processing from original image signals,

wherein the circuit is configured to form second signals by an edge enhancement processing from the first signals, and

wherein the circuit is configured to form the signals for the local dimming processing from the second signals.

17. The electronic device according to claim 13,

wherein the first light source comprises a point light source.

18. The electronic device according to claim 13,

wherein the first light source comprises of a plurality of point light sources arranged in a line.

19. The electronic device according to claim 13,

wherein the circuit is configured to form signals for a second processing selected from the group consisting of a super resolution processing, an edge enhancement processing and a frame interpolation processing, and to provide the signals to the backlight and the light modulation device.