Half reflection type liquid crystal display device having matched phase of transmitted and reflected light

Abstract

A liquid crystal display device is constructed such that a liquid crystal layer is sandwiched between an upper substrate, which is provided with upper transparent electrodes for forming pixels, and a lower substrate, which is provided with lower transparent electrodes disposed so as to intersect with the upper transparent electrodes. The liquid crystal panel includes a half reflection layer having a reflection function and a transmission function which is formed on the inner surface of the lower substrate as a lower layer of the lower transparent electrodes; an upper retardation film, an upper polarizing plate, and a light diffusing plate which are laminated on the upper substrate; and a lower retardation film and a lower polarizing plate, which are laminated on the surface of the lower substrate. Due to such a construction, the half reflection type liquid crystal display device is capable of providing an image display of high brightness and high contrast.

1. A liquid crystal panel in which a liquid crystal layer is sandwiched between an upper substrate which is provided with upper transparent electrodes for forming pixels, and a lower substrate, which is provided with lower transparent electrodes disposed so as to intersect with said upper transparent electrodes, said liquid crystal panel comprising: a half reflection layer having a reflection function and a transmission function which is formed on the inner surface of said lower substrate as a lower layer of said lower transparent electrodes; an upper retardation film, an upper polarizing plate and a light diffusing plate, which are laminated on said upper substrate; and a lower retardation film and a lower polarizing plate, which are laminated on the surface of said lower substrate; and wherein the phase of said reflected light at said half reflecting layer and the phase of a transmitted light which passes through said half reflection layer from said lower substrate substantially agree with each other. 
     
     
       2. A liquid crystal display device according to  claim 1 , wherein the transmission factor of said half reflection layer is made uniform within a display range of said liquid crystal panel. 
     
     
       3. A liquid crystal display device according to  claim 1 , wherein a back lighting device is disposed at the back side of said liquid crystal panel. 
     
     
       4. A liquid crystal display device according to  claim 3 , wherein a touch panel is disposed at the front surface side of said liquid crystal panel. 
     
     
       5. A liquid crystal panel in which a liquid crystal layer is sandwiched between an upper substrate, which is provided with upper transparent electrodes for forming pixels and a lower substrate, which is provided with lower transparent electrodes disposed so as to intersect with said upper transparent electrodes, said liquid crystal panel comprising: a half reflection layer having a reflection function and a transmission function which is formed on the inner surface of said lower substrate as a lower layer of said lower transparent electrodes; an upper retardation film, an upper polarizing plate and a light diffusing plate, which are laminated on said upper substrate; and a lower retardation film and a lower polarizing plate, which are laminated on the surface of said lower substrate; said liquid crystal panel further including a color filter layer of a plurality of colors which is formed on the inner surface of said upper substrate as a lower layer of said upper transparent electrodes, and a passivation film formed between said color filter layer and said upper transparent electrodes, and the retardation Δnd of said lower retardation film being determined such that the phase of transmitted light which passes through said lower polarizing plate, said lower retardation film and said half reflection layer becomes equivalent to the phase of reflected light by said half reflection layer. 
     
     
       6. A liquid crystal display device according to  claim 5 , wherein the transmission factor of said half reflection layer is made uniform within a display range of said liquid crystal panel. 
     
     
       7. A liquid crystal display device according to  claim 5 , wherein a back lighting device is disposed at the back side of said liquid crystal panel. 
     
     
       8. A liquid crystal display device according to  claim 7 , wherein a touch panel is disposed at the front surface side of said liquid crystal panel. 
     
     
       9. A liquid crystal panel in which a liquid crystal layer is sandwiched between an upper substrate, which is provided with upper transparent electrodes for forming pixels, and a lower substrate, which is provided with lower transparent electrodes disposed so as to intersect with said upper transparent electrodes, said liquid crystal panel comprising: a half reflection layer having a reflection function and a transmission function which is formed on the inner surface of said lower substrate as a lower layer of said lower transparent electrodes; an upper retardation film, an upper polarizing plate and a light diffusing plate which are laminated on said upper substrate; and a lower retardation film and a lower polarizing plate, which are laminated on the surface, of said lower substrate, said liquid crystal panel further including a color filter layer of a plurality of colors which is formed on the inner surface of said upper substrate as a lower layer of said upper transparent electrodes, and a passivation layer formed between said color filter layer and said upper transparent electrodes, and wherein the phase difference between the phase of a transmitted light which passes through said lower polarizing plate, said lower retardation film and said half reflection layer and the phase of a reflected light at said half reflection layer is set within ±π/ 4 when a bright display is performed . 
     
     
       10. A liquid crystal display device according to  claim 9 , wherein the transmission factor of said half reflection layer is made uniform within a display range of said liquid crystal panel. 
     
     
       11. A liquid crystal display device according to  claim 9 , wherein a back lighting device is disposed at the back side of said liquid crystal panel. 
     
     
       12. A liquid crystal display device according to  claim 11 , wherein a touch panel is disposed at the front surface side of said liquid crystal panel. 
     
     
       13. A liquid crystal panel in which a liquid crystal layer is sandwiched between an upper substrate and a lower substrate, said liquid crystal panel comprising:
   a half reflection layer having a reflection function and a transmission function, said half reflection layer being disposed at an inner surface of said lower substrate;        an upper retardation film and an upper polarizing plate being laminated on a surface of said upper substrate; and        a lower retardation film and a lower polarizing plate being laminated on a surface of said lower substrate;        wherein a phase difference of a polarization condition of reflected light at said half reflection layer and a phase difference of a polarization condition of transmitted light which passes through said half reflection layer from said lower substrate substantially agree with each other.     
     
     
       14. A liquid crystal panel according to  claim 13 , wherein said polarization condition of said reflected light at said half reflection layer and said polarization condition of said transmitted light at said half reflection layer are circular polarization when a bright display is performed. 
     
     
       15. A liquid crystal panel according to  claim 13 , wherein said upper substrate has upper transparent electrodes for forming pixels, said lower substrate has lower transparent electrodes disposed so as to intersect with said upper transparent electrodes, and said half reflection layer is disposed between said lower transparent electrodes and said lower substrate. 
     
     
       16. A liquid crystal panel according to  claim 13 , wherein said liquid crystal panel is an active matrix type liquid crystal panel. 
     
     
       17. A liquid crystal panel according to  claim 13 , further comprising a color filter layer. 
     
     
       18. A liquid crystal panel according to  claim 13 , wherein a transmission factor of the transmission function of said half reflection layer is uniform within a display range of said liquid crystal panel. 
     
     
       19. A liquid crystal display device comprising said liquid crystal panel according to  claim 13 , and a back lighting device disposed at a back side of said liquid crystal panel. 
     
     
       20. A liquid crystal display device according to  claim 19 , further comprising a touch panel disposed at a front surface side of said liquid crystal panel. 
     
     
       21. A liquid crystal panel in which a liquid crystal layer is sandwiched between an upper substrate and a lower substrate, said liquid crystal panel comprising:
   a half reflection layer having a reflection function and a transmission function, said half reflection layer being disposed at an inner surface of said lower substrate;        an upper retardation film and an upper polarizing plate being laminated on said upper substrate; and        a lower retardation film and a lower polarizing plate being laminated on a surface of said lower substrate;        wherein a retardation Δnd of said lower retardation film is determined so that a phase difference of a polarization condition of transmitted light which passes through said lower polarizing plate, said lower retardation film and said half reflection layer becomes substantially equivalent to a phase difference of a polarization condition of reflected light by said half reflection layer.     
     
     
       22. A liquid crystal panel according to  claim 21 , wherein said polarization condition of said reflected light at said half reflection layer and said polarization condition of said transmitted light at said half reflection layer are circular polarization when a bright display is performed. 
     
     
       23. A liquid crystal panel according to  claim 21 , wherein said upper substrate has upper transparent electrodes for forming pixels, said lower substrate has lower transparent electrodes disposed so as to intersect with said upper transparent electrodes, and said half reflection layer is disposed between said lower transparent electrodes and said lower substrate. 
     
     
       24. A liquid crystal panel according to  claim 21 , wherein said liquid crystal panel is an active matrix type liquid crystal panel. 
     
     
       25. A liquid crystal panel according to  claim 21 , further comprising a color filter layer. 
     
     
       26. A liquid crystal panel according to  claim 21 , wherein a transmission factor of the transmission function of said half reflection layer is uniform within a display range of said liquid crystal panel. 
     
     
       27. A liquid crystal display device comprising said liquid crystal panel according to  claim 21 , and a back lighting device disposed at a back side of said liquid crystal panel. 
     
     
       28. A liquid crystal display device according to  claim 27 , further comprising a touch panel disposed at a front surface side of said liquid crystal panel. 
     
     
       29. A liquid crystal panel in which a liquid crystal layer is sandwiched between an upper substrate and a lower substrate, said liquid crystal panel comprising:
   a half reflection layer having a reflection function and a transmission function, said half reflection layer being disposed at an inner surface of said lower substrate;        an upper retardation film and an upper polarizing plate being laminated on said upper substrate; and        a lower retardation film and a lower polarizing plate being laminated on a surface of said lower substrate;        wherein a difference between a phase difference of a polarization condition of transmitted light which passes through said lower polarizing plate, said lower retardation film and said half reflection layer and a phase difference of a polarization condition of reflected light at said high reflection layer is set within ±π/ 4  when a bright display is performed.     
     
     
       30. A liquid crystal panel according to  claim 29 , wherein said polarization condition of said reflected light at said half reflection layer and said polarization condition of said transmitted light at said half reflection layer are circular polarization when a bright display is performed. 
     
     
       31. A liquid crystal panel according to  claim 29 , wherein said upper substrate has upper transparent electrodes for forming pixels, said lower substrate has lower transparent electrodes disposed so as to intersect with said upper transparent electrodes, and said half reflection layer is disposed between said lower transparent electrodes and said lower substrate. 
     
     
       32. A liquid crystal panel according to  claim 29 , wherein said liquid crystal panel is an active matrix type liquid crystal panel. 
     
     
       33. A liquid crystal panel according to  claim 29 , further comprising a color filter layer. 
     
     
       34. A liquid crystal panel according to  claim 29 , wherein the transmission factor of the transmission function of said half reflection layer is uniform within a display range of said liquid crystal panel. 
     
     
       35. A liquid crystal device comprising said liquid crystal panel according to  claim 29 , and a back lighting device disposed at a back side of said liquid crystal panel. 
     
     
       36. A liquid crystal display device according to  claim 35 , further comprising a touch panel disposed at a front surface of said liquid crystal panel. 
     
     
       37. A liquid crystal panel in which a liquid crystal layer is sandwiched between an upper substrate and a lower substrate, said liquid crystal panel comprising:
   a half reflection layer having a reflection function and a transmission function, said half reflection layer being disposed at an inner surface of said lower substrate;        an upper retardation film and an upper polarizing plate being laminated on a surface of said upper substrate; and        a lower retardation film and a lower polarizing plate being laminated on a surface of said lower substrate;        wherein a phase difference of a polarization condition of reflected light at said half reflection layer and a phase difference of a polarization condition of transmitted light which passes through said half reflection layer from said lower substrate substantially agree with each other when a bright display is performed.      
     
     
       38. A liquid crystal panel according to  claim 37 , wherein said upper substrate has upper transparent electrodes for forming pixels, said lower substrate has lower transparent electrodes disposed so as to intersect with said upper transparent electrodes, and said half reflection layer is disposed between said lower transparent electrodes and said lower substrate. 
     
     
       39. A liquid crystal panel according to  claim 37 , wherein said liquid crystal panel is an active matrix type liquid crystal panel. 
     
     
       40. A liquid crystal panel according to  claim 37 , further comprising a color filter layer. 
     
     
       41. A liquid crystal panel according to  claim 37 , wherein a transmission factor of the transmission function of said half reflection layer is uniform within a display range of said liquid crystal panel. 
     
     
       42. A liquid crystal device comprising said liquid crystal panel according to  claim 37 , and a back lighting device disposed at a back side of said liquid crystal panel. 
     
     
       43. A liquid crystal device according to  claim 42 , further comprising a touch panel disposed at a front surface of said liquid crystal panel. 
     
     
       44. A liquid crystal panel in which a liquid crystal layer is sandwiched between an upper substrate and a lower substrate, said liquid crystal panel comprising:
   a half reflection layer having a reflection function and a transmission function, said half reflection layer being disposed at an inner surface of said lower substrate;        an upper retardation film and an upper polarizing plate being laminated on said upper substrate; and        a lower retardation film and a lower polarizing plate being laminated on a surface of said lower substrate;        wherein a retardation Δnd of said lower retardation film is determined so that a phase difference of a polarization condition of transmitted light which passes through said lower polarizing plate, said lower retardation film and said half reflection layer becomes substantially equivalent to a phase difference of a polarization condition of reflected light by said half reflection layer when a bright display is performed.     
     
     
       45. A liquid crystal panel according to  claim 44 , wherein said upper substrate has upper transparent electrodes for forming pixels, said lower substrate has lower transparent electrodes disposed so as to intersect with said upper transparent electrodes, and said half reflection layer is disposed between said lower transparent electrodes and said lower substrate. 
     
     
       46. A liquid crystal panel according to  claim 44 , wherein said liquid crystal panel is an active matrix type liquid crystal panel. 
     
     
       47. A liquid crystal panel according to  claim 44 , further comprising a color filter layer. 
     
     
       48. A liquid crystal panel according to  claim 44 , wherein the transmission factor of the transmission function of said half reflection layer is uniform within a display range of said liquid crystal panel. 
     
     
       49. A liquid crystal device comprising the liquid crystal panel according to  claim 44 , and a back lighting device disposed at a back side of said liquid crystal panel. 
     
     
       50. A liquid crystal device according to  claim 49 , further comprising a touch panel disposed at a front surface of said liquid crystal panel.