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. 
     
     
       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 display device comprising a liquid crystal display panel having an upper substrate, a lower substrate and a liquid crystal layer sandwiched therebetween, wherein
   said upper substrate has an upper retardation film and an upper polarizing plate;        said lower substrate has a lower retardation film and a lower polarizing plate;        a first light which comes from said upper substrate is changed into a second light by being reflected by a surface at a predetermined height H as measured from said lower substrate, where said predetermined height H exists within a space defined between said upper substrate and said lower substrate;        a third light comes from said lower substrate, passes through said predetermined height H from said lower substrate and passes through said upper substrate;        a phase difference of a polarization condition of said third light at said predetermined height H from said lower substrate and a phase difference of a polarization condition of said second light at said predetermined height H from said lower substrate substantially agree with each other when a white display is performed.     
     
     
       14. A liquid crystal display device according to  claim 13 , wherein said polarization condition of said second light at said predetermined height H from said lower substrate and said polarization condition of said third light at said predetermined height H from said lower substrate are circular polarization when a white display is performed. 
     
     
       15. A liquid crystal display device 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. 
     
     
       16. A liquid crystal display device according to  claim 13 , wherein said liquid crystal display panel is an active matrix type liquid crystal display panel. 
     
     
       17. A liquid crystal display device according to  claim 13 , comprising a color filter layer. 
     
     
       18. A liquid crystal display device according to  claim 13 , comprising a back lighting device disposed at a back side of said lower substrate. 
     
     
       19. A liquid crystal display device according to  claim 13 , wherein said surface is a reflecting surface of a reflection layer provided within the space defined between said upper substrate and said lower substrate. 
     
     
       20. A liquid crystal display device comprising a liquid crystal display panel having an upper substrate, a lower substrate and a liquid crystal layer sandwiched therebetween, wherein
   said upper substrate has an upper retardation film and an upper polarizing plate;        said lower substrate has a lower retardation film and a lower polarizing plate;        a first light which comes from said upper substrate is changed into a second light by being reflected by a surface at a predetermined height H as measured from said lower substrate, where said predetermined height H exists within a space defined between said upper substrate and said lower substrate;        a third light comes from said lower substrate, passes through said predetermined height H from said lower substrate and passes through said upper substrate;        a retardation Δnd of said lower retardation film is determined so that a phase difference of a polarization condition of said third light at said predetermined height H from said lower substrate becomes substantially equivalent to a phase difference of a polarization condition of said second light at said predetermined height H from said lower substrate when a white display is performed.     
     
     
       21. A liquid crystal display device according to  claim 20 , wherein said polarization condition of said second light at said predetermined height H from said lower substrate and said polarization condition of said third light at said predetermined height H from said lower substrate are circular polarization when a white display is performed. 
     
     
       22. A liquid crystal display device according to  claim 20 , 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. 
     
     
       23. A liquid crystal display device according to  claim 20 , wherein said liquid crystal display panel is an active matrix type liquid crystal display panel. 
     
     
       24. A liquid crystal display device according to  claim 20 , comprising a color filter layer. 
     
     
       25. A liquid crystal display device according to  claim 20 , comprising a back lighting device disposed at a back side of said lower substrate. 
     
     
       26. A liquid crystal display device according to  claim 20 , wherein said surface is a reflecting surface of a reflection layer provided within the space defined between said upper substrate and said lower substrate. 
     
     
       27. A liquid crystal display device comprising a liquid crystal display panel having an upper substrate, a lower substrate and a liquid crystal layer sandwiched therebetween, wherein
   said upper substrate has an upper retardation film and an upper polarizing plate;        said lower substrate has a lower retardation film and a lower polarizing plate;        a first light which comes from said upper substrate is changed into a second light by being reflected by a surface at a predetermined height H as measured from said lower substrate, where said predetermined height H exists within a space defined between said upper substrate and said lower substrate;        a third light comes from said lower substrate, passes through said predetermined height H from said lower substrate and passes through said upper substrate;        a difference between a phase difference of a polarization condition of said second light at said predetermined height H from said lower substrate and a phase difference of a polarization condition of said third light at said predetermined height H from said lower substrate is set within ±π/ 4  when a white display is performed.     
     
     
       28. A liquid crystal display device according to  claim 27 , wherein said polarization condition of said second light at said predetermined height H from said lower substrate and said polarization condition of said third light at said predetermined height H from said lower substrate are circular polarization when a white display is performed. 
     
     
       29. A liquid crystal display device according to  claim 27 , 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. 
     
     
       30. A liquid crystal display device according to  claim 27 , wherein said liquid crystal display panel is an active matrix type liquid crystal display panel. 
     
     
       31. A liquid crystal display device according to  claim 27 , comprising a color filter layer. 
     
     
       32. A liquid crystal display device according to  claim 27 , comprising a back lighting device disposed at a back side of said lower substrate. 
     
     
       33. A liquid crystal display device according to  claim 27 , wherein said surface is a reflecting surface of a reflection layer provided within the space defined between said upper substrate and said lower substrate. 
     
     
       34. A liquid crystal display device comprising a liquid crystal display panel having an upper substrate, a lower substrate and a liquid crystal layer sandwiched therebetween, wherein
   said upper substrate has an upper retardation film and an upper polarizing plate;        said lower substrate has a lower retardation film and a lower polarizing plate;        a first light which comes from said upper substrate is changed into a second light by being reflected by a surface at a predetermined height H as measured from said lower substrate, where said predetermined height H exists within a space defined between said upper substrate and said lower substrate;        a third light comes from said lower substrate, passes through said predetermined height H from said lower substrate and passes through said upper substrate;        a phase difference of a polarization condition of said second light at said predetermined height H from said lower substrate and a phase difference of a polarization condition of said third light at said predetermined height H from said lower substrate substantially agree with each other.     
     
     
       35. A liquid crystal display device according to  claim 34 , wherein said polarization condition of said second light at said predetermined height H from said lower substrate and said polarization condition of said third light at said predetermined height H from said lower substrate are circular polarization when a white display is performed. 
     
     
       36. A liquid crystal display device according to  claim 34 , 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. 
     
     
       37. A liquid crystal display device according to  claim 34 , wherein said liquid crystal display panel is an active matrix type liquid crystal display panel. 
     
     
       38. A liquid crystal display device according to  claim 34 , comprising a color filter layer. 
     
     
       39. A liquid crystal display device according to  claim 34 , comprising a back lighting device disposed at a back side of said lower substrate. 
     
     
       40. A liquid crystal display device according to  claim 34 , wherein said surface is a reflecting surface of a reflection layer provided within the space defined between said upper substrate and said lower substrate. 
     
     
       41. A liquid crystal display device comprising a liquid crystal display panel having an upper substrate, a lower substrate and a liquid crystal layer sandwiched therebetween, wherein
   said upper substrate has an upper retardation film and an upper polarizing plate;        said lower substrate has a lower retardation film and a lower polarizing plate;        a first light which comes from said upper substrate is changed into a second light by being reflected by a surface at a predetermined height H as measured from said lower substrate, where said predetermined height H exists within a space defined between said upper substrate and said lower substrate;        a third light comes from said lower substrate, passes through said predetermined height H from said lower substrate and passes through said upper substrate;        a retardation Δnd of said lower retardation film is determined so that a phase difference of a polarization condition of said third light at said predetermined height H from said lower substrate becomes substantially equivalent to a phase difference of a polarization condition of said second light at said predetermined height H from said lower substrate.     
     
     
       42. A liquid crystal display device according to  claim 41 , wherein said polarization condition of said second light at said predetermined height H from said lower substrate and said polarization condition of said third light at said predetermined height H from said lower substrate are circular polarization when a white display is performed. 
     
     
       43. A liquid crystal display device according to  claim 41 , 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. 
     
     
       44. A liquid crystal display device according to  claim 41 , wherein said liquid crystal display panel is an active matrix type liquid crystal display panel. 
     
     
       45. A liquid crystal display device according to  claim 41 , comprising a color filter layer. 
     
     
       46. A liquid crystal display device according to  claim 41 , comprising
   a back lighting device disposed at a back side of said lower substrate.     
     
     
       47. A liquid crystal display device according to  claim 41 , wherein said surface is a reflecting surface of a reflection layer provided within the space defined between said upper substrate and said lower substrate.