Liquid crystal display device

Abstract

According to one embodiment, a display device includes a first substrate, a second substrate, a liquid crystal layer, a first alignment film, a pixel electrode, and a common electrode. The liquid crystal layer is disposed between the first substrate and the second substrate. The first alignment film is provided on the first substrate to be in contact with the liquid crystal layer. The pixel electrode is provided on the first substrate and covered with the first alignment film. The common electrode provided on the first substrate to form a lateral electric field. The liquid crystal layer is driven at a frequency of 40 Hz or less. A time constant of the liquid crystal layer is larger than a time constant of the first alignment film.

1 - 20 . (canceled) 
     
     
         21 : A display device comprising:
 a first substrate;   a second substrate opposed to the first substrate;   a liquid crystal layer disposed between the first substrate and the second substrate;   a first alignment film provided on the first substrate to be in contact with the liquid crystal layer;   a second alignment film provided on the second substrate to be in contact with the liquid crystal layer;   a pixel electrode provided on the first substrate and covered with the first alignment film; and   a common electrode provided on the first substrate to form a lateral electric field between the pixel electrode and the common electrode,   wherein   the liquid crystal layer is driven at a frame frequency of 40 Hz or less,   the pixel electrode is connected to a transistor comprising a silicon semiconductor,   a voltage variation rate of the liquid crystal layer is increased in one frame, and   the voltage variation rate is according to a formula:
   voltage variation rate=( Vf−Vi )/ Vi,    
   wherein Vi is a voltage of the liquid crystal layer at a start of the one flame, Vf is a voltage of the liquid crystal layer at an end of the one frame.   
     
     
         22 : The display device of  claim 21 , wherein
 the liquid crystal layer contains liquid crystal molecules having a negative dielectric anisotropy.   
     
     
         23 : The display device of  claim 21 , wherein
 the first alignment film is an optical alignment film.   
     
     
         24 : The display device of  claim 21 , wherein
 a time constant of the first alignment film is 1.0×10 10  sec or more and 2.0×10 13  sec or less, and a time constant of the liquid crystal layer is 8.0×10 13  sec or less.   
     
     
         25 : The display device of  claim 21 , wherein
 a resistivity of the first alignment film is 1.0×10 11  Ω·cm or more and 5.0×10 15  Ω·cm or less.   
     
     
         26 : The display device of  claim 21 , wherein
 a difference between a time constant of the first alignment film and a time constant of the liquid crystal layer is 4.0×10 3  sec or less.   
     
     
         27 : The display device of  claim 21 , wherein
 the liquid crystal layer is driven at a frequency of 20 Hz or more, and   a difference between a time constant of the first alignment film and a time constant of the liquid crystal layer is 4.0×10 2  sec or less.   
     
     
         28 : A display device comprising:
 a first substrate;   a second substrate opposed to the first substrate;   a liquid crystal layer disposed between the first substrate and the second substrate;   a first alignment film provided on the first substrate to be in contact with the liquid crystal layer;   a second alignment film provided on the second substrate to be in contact with the liquid crystal layer;   a pixel electrode provided on the first substrate and covered with the first alignment film; and   a common electrode provided on the first substrate to form a lateral electric field between the pixel electrode and the common electrode,   wherein   the liquid crystal layer is driven at a frame frequency of 40 Hz or less,   the pixel electrode is connected to a transistor comprising a silicon semiconductor,   a luminance of the display device is gradually increased from a start to an end of one frame.   
     
     
         29 : The display device of  claim 28 , wherein
 the liquid crystal layer contains liquid crystal molecules having a negative dielectric anisotropy.   
     
     
         30 : The display device of  claim 28 , wherein
 the first alignment film is an optical alignment film.   
     
     
         31 : The display device of  claim 28 , wherein
 a time constant of the first alignment film is 1.0×10 10  sec or more and 2.0×10 13  sec or less, and a time constant of the liquid crystal layer is 8.0×10 13  sec or less.   
     
     
         32 : The display device of  claim 28 , wherein
 a resistivity of the first alignment film is 1.0×10 11  Ω·cm or more and 5.0×10 15  Ω·cm or less.   
     
     
         33 : The display device of  claim 28 , wherein
 a difference between a time constant of the first alignment film and a time constant of the liquid crystal layer is 4.0×10 3  sec or less.   
     
     
         34 : The display device of  claim 28 , wherein
 the liquid crystal layer is driven at a frequency of 20 Hz or more, and   a difference between a time constant of the first alignment film and a time constant of the liquid crystal layer is 4.0×10 2  sec or less.