Display device

Abstract

A display device including a display module, a light source module, a turning optical film, a first compensation film and a second compensation film is provided. The display module includes a first substrate, a second substrate and a display medium. The light source module generates directional light. The display module is disposed above the light source module. The second substrate is disposed opposite to the first substrate. The display medium is disposed between the first substrate and the second substrate and is optically isotropic. The turning optical film is disposed on the second substrate of the display module. The directional light enters the turning optical film and then exits the turning optical film to form an output light. The first compensation film is disposed on the first outer surface of the first substrate. The second compensation film is disposed between the second substrate and the turning optical film.

1 . A display device, comprising:
 a light source module generating a directional light;   a display module disposed above the light source module, the display module comprising:
 a first substrate having a first inner surface and a first outer surface; 
 a second substrate disposed opposite to the first substrate and having a second inner surface and a second outer surface; and 
 a display medium disposed between the first substrate and the second substrate and is optically isotropic, wherein the display medium is optically anisotropic when driven with an electric field, the directional light is not perpendicular to the first outer surface when the directional light enters the display module, and the directional light is not perpendicular to the second outer surface when the directional light exits the display module; 
   a turning optical film disposed on the second outer surface of the second substrate of the display module, the turning optical film having an incident surface and an output surface, the directional light entering the turning optical film from the incident surface and exiting the turning optical film from the output surface so as to form an output light, wherein an included angle is between the output light and the output surface;   a first compensation film disposed on the first outer surface of the first substrate; and   a second compensation film disposed between the second substrate and the turning optical film.   
     
     
         2 . The display device as claimed in  claim 1 , further comprising:
 a first optical film disposed on the first outer surface of the first substrate, the first optical film having a plurality of first optical structures allowing the directional light passing through the first optical structures without generating total reflection; and   a second optical film disposed on the second outer surface of the second substrate, wherein the second optical film has a plurality of second optical structures substantially allowing the directional light passing through the first optical structures without generating total reflection.   
     
     
         3 . The display device as claimed in  claim 2 , further comprising:
 a bottom polarizer disposed on the first outer surface of the first substrate; and   a top polarizer disposed on the second outer surface of the second substrate.   
     
     
         4 . The display device as claimed in  claim 3 , wherein the bottom polarizer is disposed between the first compensation film and the first optical film, the top polarizer is disposed between the second compensation film and the second optical film, and the second optical film is disposed between the turning optical film and the top polarizer. 
     
     
         5 . The display device as claimed in  claim 4 , wherein an orientation angle of the first compensation film is 20°˜50° and Nz is 0.35˜0.75; and an orientation angle of the second compensation film is −20°˜−50° and Nz is 0.35˜0.75. 
     
     
         6 . The display device as claimed in  claim 3 , further comprising:
 a third compensation film disposed between the first compensation film and the bottom polarizer; and   a fourth compensation film disposed between the second compensation film and the top polarizer; and   
     
     
         7 . The display device as claimed in  claim 6 , wherein the third compensation film and the fourth compensation film are respectively a biaxial compensation film. 
     
     
         8 . The display device as claimed in  claim 7 , wherein an orientation angle of the first compensation film is 20°˜40° and Nz is 0.25˜0.55; an orientation angle of the second compensation film is −20°˜−40° and Nz is 0.25˜0.55; an orientation angle of the third compensation film is 15°˜35° and Nz is 0.75˜0.95; and an orientation angle of the fourth compensation film is −15°˜−35° and Nz is 0.75˜0.95. 
     
     
         9 . The display device as claimed in  claim 6 , wherein the bottom polarizer is a wire-grid polarizer. 
     
     
         10 . The display device as claimed in  claim 9 , wherein an orientation angle of the first compensation film is 30°˜60° and Nz is 0.35˜0.65; an orientation angle of the second compensation film is −30°˜−60° and Nz is 0.35˜0.65; an orientation angle of the third compensation film is −10°˜10° and Nz is 0.71˜0.91; and an orientation angle of the fourth compensation film is 80°˜100° and Nz is 0.71˜0.91. 
     
     
         11 . The display device as claimed in  claim 3 , further comprising:
 a third compensation film disposed between the first compensation film and the first substrate; and   a fourth compensation film disposed between the second compensation film and the second substrate.   
     
     
         12 . The display device as claimed in  claim 11 , wherein the third compensation film and the fourth compensation film are respectively a biaxial compensation film. 
     
     
         13 . The display device as claimed in  claim 12 , wherein an orientation angle of the first compensation film is 25°˜55° and Nz is 0.45˜0.75; an orientation angle of the second compensation film is −25°˜−55° and Nz is 0.47˜0.67; an orientation angle of the third compensation film is 80°˜100° and Nz is 0.4˜0.6; and an orientation angle of the fourth compensation film is −10°˜10° and Nz is 0.4˜0.6. 
     
     
         14 . The display device as claimed in  claim 3 , wherein the first compensation film and the second compensation film are respectively a biaxial compensation film. 
     
     
         15 . The display device as claimed in  claim 14 , further comprising:
 a third compensation film disposed between the bottom polarizer and the first compensation film, and the first optical film is disposed between the third compensation film and the first compensation film; and   a fourth compensation film disposed between the second compensation film and the top polarizer, and the second optical film is disposed between the fourth compensation film and the top polarizer.   
     
     
         16 . The display device as claimed in  claim 15 , wherein the turning optical film is disposed between the second optical film and the top polarizer. 
     
     
         17 . The display device as claimed in  claim 16 , wherein the third compensation film is a biaxial compensation film, and the fourth compensation film comprises an A-plate compensation film and a C-plate compensation film. 
     
     
         18 . The display device as claimed in  claim 17 , wherein an orientation angle of the first compensation film is 100°˜125° and Nz is 0.55˜0.8; an orientation angle of the second compensation film is 10°˜35° and Nz is 0.8˜1.0; an orientation angle of the third compensation film is −10°˜10° and Nz is 0.6˜0.8; an orientation angle of the A-plate compensation film is −10°˜10°, n o  is 1.4˜1.6, and n e  is 1.4˜1.6; and n o  of the C-plate compensation film is 1.4˜1.6 and n e  is 1.4˜1.6. 
     
     
         19 . The display device as claimed in  claim 14 , further comprising:
 a third compensation film disposed between the bottom polarizer and the first compensation film, and the bottom polarizer is disposed between the first optical film and the third compensation film; and   a fourth compensation film disposed between the second compensation film and the top polarizer, and the second optical film is disposed between the fourth compensation film and the top polarizer.   
     
     
         20 . The display device as claimed in  claim 19 , wherein the turning optical film is disposed between the second optical film and the top polarizer. 
     
     
         21 . The display device as claimed in  claim 20 , wherein the third compensation film is a biaxial compensation film, and the fourth compensation film comprises an A-plate compensation film and a C-plate compensation film. 
     
     
         22 . The display device as claimed in  claim 21 , wherein an orientation angle of the first compensation film is −35°˜−55° and Nz is 0.4˜0.6; an orientation angle of the second compensation film is 35°˜55° and Nz is 0.4˜0.6; an orientation angle of the third compensation film is −10°˜10° and Nz is 0.45˜0.65; an orientation angle of the A-plate compensation film is −10°˜10°, n o  is 1.4˜1.6, and n e  is 1.4˜1.6; and n o  of the C-plate compensation film is 1.4˜1.6 and n e  is 1.4˜1.6. 
     
     
         23 . The display device as claimed in  claim 3 , wherein the bottom polarizer comprises an O-type polarizer, and the top polarizer comprises an E-type polarizer. 
     
     
         24 . The display device as claimed in  claim 23 , wherein an orientation angle of the first compensation film is −35°˜−55° and Nz is 0.4˜0.6; and an orientation angle of the second compensation film is 35°˜55° and Nz is 0.4˜0.6. 
     
     
         25 . The display device as claimed in  claim 1 , wherein the included angle is 60°˜120°. 
     
     
         26 . The display device as claimed in  claim 25 , wherein the included angle is 90°. 
     
     
         27 . The display device as claimed in  claim 1 , further comprising a diffusion film disposed on the turning optical film.