Liquid crystal display device comprising a picture element region including different electric field strength regions

Abstract

A first electrode 14 provided in a liquid crystal display device of a vertical alignment mode includes, for each picture element region, a lower conductive layer 11, a dielectric layer 12 covering the lower conductive layer 11, and an upper conductive layer 13 provided on one side of the dielectric layer 12 which is closer to a liquid crystal layer 30. The upper conductive layer 13 includes an upper layer opening 13 a, and the lower conductive layer 11 includes a lower layer opening 11 a, thus forming first, second and third regions (R 1, R 2, R 3 ) having gradually decreasing electric field strengths. Liquid crystal molecules 30 a of the liquid crystal layer 30 in an orientation-regulating region T 1 in which the first, second and third regions are arranged in this order in a predetermined direction change the orientation direction thereof so that they are inclined in a single direction in the presence of an applied voltage.

What is claimed is: 
     
       1. A liquid crystal display device, comprising:
 a first substrate, a second substrate and a liquid crystal layer interposed between the first substrate and the second substrate, wherein: 
 a picture element region comprises a first electrode provided on one side of the first substrate which is closer to the liquid crystal layer and a second electrode provided on the second substrate so as to oppose the first electrode via the liquid crystal layer; 
 the liquid crystal layer is a vertical alignment type liquid crystal layer containing a liquid crystal material having a negative dielectric anisotropy; and 
 the picture element region includes at least one orientation-regulating region, the orientation-regulating region including a first region in which an electric field applied across the liquid crystal layer by the first electrode and the second electrode has a first electric field strength, a second region in which the electric field has a second electric field strength which is smaller than the first electric field strength, and a third region in which the electric field has a third electric field strength which is smaller than the second electric field strength, wherein the first, second and third regions are arranged in this order in a predetermined direction; 
 wherein a boundary between the first region and the second region, and a boundary between the second region and the third region, are each oriented so as to each extend substantially only in a single direction which is perpendicular to the predetermined direction; 
 wherein the display includes a plurality of the picture element regions including respective ones of the first electrodes arranged in a matrix having row and column directions, and wherein both the predetermined direction and the single direction are angled relative to the column direction; 
 a third electrode in the pixel element region, the first electrode being provided on one side of the first substrate which is closer to the liquid crystal layer than said third electrode; 
 wherein in said second region the electric field is applied across the liquid crystal layer by said third electrode and the second electrode and has a second electric field strength which is smaller than the first electric field strength, and; 
 wherein in the third region the electric field applied across the liquid crystal layer by at least a slit and/or aperture region of the third electrode and the second electrode has a third electric field strength which is smaller than the second electric field strength; and 
 wherein voltages applied to the first electrodes are supplied independently for each pixel region. 
 
     
     
       2. A liquid crystal display device, comprising:
 a first substrate, a second substrate and a liquid crystal layer interposed between the first substrate and the second substrate, wherein:   a plurality of picture element regions are provided each of which is defined by a first electrode provided on one side of the first substrate which is closer to the liquid crystal layer and a second electrode provided on the second substrate so as to oppose the first electrode via the liquid crystal layer;   the liquid crystal layer is a vertical alignment type liquid crystal layer containing a liquid crystal material having a negative dielectric anisotropy;   the first electrode includes a lower conductive layer, a dielectric layer covering the lower conductive layer, and an upper conductive layer provided on one side of the dielectric layer which is closer to the liquid crystal layer; the upper conductive layer includes an upper layer opening for each of the plurality of picture element regions, and the lower conductive layer includes a lower layer opening for each of the plurality of picture element regions;   at least one of the plurality of picture element regions includes a first region in which the liquid crystal layer is arranged between the upper conductive layer of the first electrode and the second electrode, a second region in which the liquid crystal layer and the dielectric layer located within the upper layer opening are arranged between the lower conductive layer of the first electrode and the second electrode, and a third region in which the liquid crystal layer and the dielectric layer located within the upper layer opening are arranged between the lower layer opening of the first electrode and the second electrode;   wherein, in a plane of the at least one picture element region, the third region is substantially entirely enclosed inside the second region, and the second region is substantially entirely enclosed inside the first region, and under the application of a voltage between the first and second electrodes, an axially symmetrical orientation is formed around the lower layer opening; and   wherein voltages applied to the upper conductive layer are supplied independently for each pixel region.   
     
     
       3. The liquid crystal display device of claim 2, wherein a boundary between the first and the second regions includes four sides each of which is parallel to one of outer edges of the upper conductive layer. 
     
     
       4. The liquid crystal display device of claim 2, wherein the lower layer opening has a polygonal shape or a circle. 
     
     
       5. The liquid crystal display device of claim 2, wherein the lower layer opening does not have a convex polygonal shape. 
     
     
       6. The liquid crystal display device of claim 2, wherein the first electrode is a picture element electrode. 
     
     
       7. The liquid crystal display device of claim 2, wherein the second electrode is a common electrode. 
     
     
       8. The liquid crystal display device of claim 2, wherein a potential of the lower conductive layer (Va), a potential of the upper conductive layer (Vb), and a potential of the second electrode (Vc) satisfy a relationship where Vb≦Va<Vc or Vb≧Va>Vc.