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

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.

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.