Liquid crystal display apparatus

Abstract

A liquid crystal display apparatus provided with liquid crystal compensation plates and λ/4 plates on both sides of a liquid crystal cell, in a sequence that the liquid crystal compensation plates, then the λ/4 plates. Further provided is Rth compensation film between the λ/4 plate and linear polarization film. Set substantially at zero is a retardation Rth 1 in a perpendicular direction in a range from the linear polarization films to the λ/4 plates, excluding the λ/4 plates. This gives a retardation (in a perpendicular direction) for optically compensating the liquid crystal cell a closer position to the liquid crystal cell. As a result, a broad angle of visibility can be maintained, without losing a balance between viewing angle characteristics from the above position (or the bottom position) and those from the right position (or the left position), while it is possible to prevent contrast ratio in a front direction from being lowered. Therefore, an LCD having good display quality can be realized.

1 . A liquid crystal display apparatus, comprising:
 a liquid crystal cell;   polarizers provided on both sides of said liquid crystal cell;   quarter wavelength layers, provided between said respective polarizers and said liquid crystal cell, each of said quarter wavelength layers having a retardation in an in-plane direction that is substantially set at a quarter wavelength of a wavelength of transmitted light;   a phase difference layer, provided between at least one of said quarter wavelength layers and said liquid crystal cell, which has a retardation in a perpendicular direction, and optically compensates said liquid crystal cell; and   a compensation layer provided at least between the polarizer and said quarter wavelength layer on the side of said phase difference layer,   wherein said compensation layer has a retardation in a perpendicular direction whose sign is reverse to a sum of the retardations in the perpendicular direction from said polarizer to said quarter wavelength layer, but excluding said compensation layer.   
   
   
       2 . (canceled) 
   
   
       3 . The liquid crystal display apparatus as set forth in  claim 1 , wherein:
 said liquid crystal cell includes a first substrate having a pixel electrode that corresponds to a pixel, a second substrate having an opposite electrode, and a liquid crystal layer that is provided between said first and second substrates; and   said liquid crystal layer is controlled so that liquid crystal molecules have alignment directions different from each other in the pixel, at least when a voltage between said pixel electrode and said opposite electrode is a predetermined voltage.   
   
   
       4 . The liquid crystal display apparatus as set forth in  claim 1 , wherein said phase difference layer has respective main refraction indexes nx 1  and ny 1  so as to satisfy nx 1 =ny 1 . 
   
   
       5 . The liquid crystal display apparatus as set forth in  claim 1 , wherein:
 said phase difference layers are provided between said respective quarter wavelength layers and The liquid crystal cell, have different main refraction indexes nx 1  and ny 1 , respectively; and   said nx 1  axes of said phase difference layers cross each other at a right angle, while said ny 1  axes of said phase difference layers cross each other at a right angle.   
   
   
       6 . The liquid crystal display apparatus as set forth in  claim 1 , wherein both said quarter wavelength layers have the retardation in the perpendicular direction identical with each other in terms of the sign. 
   
   
       7 - 107 . (canceled)