Liquid crystal display device, electronic device, and driving methods thereof

• US 20080284720A1
• Filed: 05/12/2008
• Published: 11/20/2008
• Est. Priority Date: 05/18/2007
• Status: Abandoned Application

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Fukutome, Takahiro
• Application Number:
  US12/149,978
• Publication Number:
  US 20080284720A1
• Time in Patent Office: Days
• US Class Current: 345/102
• CPC Class Codes: G02F 1/133351 Manufacturing of individual cells out of a plurality of cells, e.g. by dicing
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 2201/58 Arrangements comprising a monitoring photodetector
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336

Abstract

An object of the present invention is to provide a driving method by which excellent image quality and high video performance can be obtained as well as liquid crystal display devices and electronic devices with excellent image quality and high video performance. A pixel for monitor use is provided in a liquid crystal display device, and luminance of the pixel is detected using a light sensor. Herewith, because changes in luminance of a backlight with changes in the environment and the amount of time it takes for response of the liquid crystal become able to be calculated, control of the backlight in real time using the calculated information can be performed.

Claims

1. A liquid crystal display device comprising:

a light source for monitor use;

a liquid crystal layer;

a backlight for emitting light to the liquid crystal layer; and

a light sensor used to detect an intensity of light passing through the liquid crystal layer from the light source for monitor use.

2. The liquid crystal display device according to claim 1, further comprising:

a unit configured to calculate an amount of correction for a luminance of the backlight based on the intensity of light from the light source for monitor use that is detected by the light sensor; and

a unit configured to control the luminance of the backlight based on the amount of correction for the luminance of the backlight that is calculated.

3. The liquid crystal display device according to claim 1, further comprising:

a unit configured to calculate timing of the backlight being turned on and timing of the backlight being turned off based on the intensity of light from the light source for monitor use that is detected by the light sensor; and

a unit configured to control the backlight being turned on and the backlight being turned off based on the timing of the backlight being turned on and the timing of the backlight being turned off that are calculated.

4. The liquid crystal display device according to claim 1,

wherein the light source for monitor use and the backlight are each provided on one side of the liquid crystal layer.

5. The liquid crystal display device according to claim 1,

wherein the light source for monitor use is one part of the backlight.

6. The liquid crystal display device according to claim 1,

wherein the light source for monitor use is provided on one side of the liquid crystal layer and the backlight is provided on a side of the liquid crystal layer opposite from the side on which the light source for monitor use is provided.

7. The liquid crystal display device according to claim 1, further comprising a light sensor used to detect an intensity of external light.

8. An electronic device in which the liquid crystal display device according to claim 1 is used.

9. A liquid crystal display device comprising:

a liquid crystal layer;

a first polarizing plate and a second polarizing plate, the liquid crystal layer is sandwiched between the first polarizing plate and the second polarizing plate;

a light source for monitor use provided on a side of the first polarizing plate;

a backlight for emitting light to the liquid crystal layer; and

a light sensor provided on a side of the second polarizing plate,

wherein the light sensor is arranged so as to detect an intensity of light from the light source for monitor use.

10. The liquid crystal display device according to claim 9, further comprising:

a unit configured to calculate an amount of correction for a luminance of the backlight based on the intensity of light from the light source for monitor use that is detected by the light sensor; and

a unit configured to control the luminance of the backlight based on the amount of correction for the luminance of the backlight that is calculated.

11. The liquid crystal display device according to claim 9, further comprising:

a unit configured to calculate timing of the backlight being turned on and timing of the backlight being turned off based on the intensity of light from the light source for monitor use that is detected by the light sensor; and

a unit configured to control the backlight being turned on and the backlight being turned off based on the timing of the backlight being turned on and the timing of the backlight being turned off that are calculated.

12. The liquid crystal display device according to claim 9,

wherein the light source for monitor use and the backlight are each provided on one side of the liquid crystal layer.

13. The liquid crystal display device according to claim 9,

wherein the light source for monitor use is one part of the backlight.

14. The liquid crystal display device according to claim 9,

wherein the light source for monitor use is provided on one side of the liquid crystal layer and the backlight is provided on a side of the liquid crystal layer opposite from the side on which the light source for monitor use is provided.

15. The liquid crystal display device according to claim 9, further comprising a light sensor used to detect an intensity of external light.

16. An electronic device in which the liquid crystal display device according to claim 9 is used.

17. A driving method for a liquid crystal display device comprising:

detecting an intensity of light passing through a liquid crystal layer from a light source for monitor use; and

controlling a luminance of a backlight based on the intensity of light from the light source for monitor use that is detected.

18. The driving method for a liquid crystal display device according to claim 17,

wherein controlling the luminance of the backlight is performed based on an amount of correction for the luminance of the backlight, and

wherein the amount of correction for the luminance of the backlight is calculated based on the intensity of light from the light source for monitor use that is detected.

19. The driving method for a liquid crystal display device according to claim 17,

wherein controlling the luminance of the backlight is performed based on an amount of correction for the luminance of the backlight, and

wherein the amount of correction for the luminance of the backlight is calculated based on brightness of surroundings detected by a light sensor that is used to detect the intensity of external light.

20. A driving method for a liquid crystal display device comprising:

detecting an intensity of light passing through a liquid crystal layer from a light source for monitor use; and

controlling a backlight being turned on and the backlight being turned off based on the intensity of light from the light source for monitor use that is detected.

21. The driving method for a liquid crystal display device according to claim 20,

wherein controlling the backlight being turned on and the backlight being turned off is performed based on timing of the backlight being turned on and timing of the backlight being turned off, and

wherein the timing of the backlight being turned on and the timing of the backlight being turned off are calculated based on the intensity of light from the light source for monitor use that is detected.