Liquid crystal display apparatus

Abstract

A liquid crystal display apparatus is provided in which occurrence of a moiré pattern can be prevented without largely reducing front luminance. A liquid crystal display apparatus 1 includes a surface light source 4 , a liquid crystal display panel 2 , and first and second prism sheets 5 and 6 for condensing light emitted from the surface light source 4 and guiding the light toward the liquid crystal display panel. The first and second prism sheets 5 and 6 are disposed such that prism array directions thereof are orthogonal to each other. When a pixel pitch of the liquid crystal display panel 2 is defined as Pp [μm]; a prism array pitch of the first prism sheet 5 is defined as Px [μm]; and a prism array pitch of the second prism sheet 6 is defined as Py [μm], relationships of Px≤Pp/(14−0.045 Pp) and Py≤Pp/(11.5−0.032 Pp) are satisfied.

The invention claimed is: 
     
       1. A liquid crystal display apparatus comprising:
 a light source;   a liquid crystal display panel;   and condenser sheets for condensing light emitted from the light source and guiding the light toward the liquid crystal display panel,   the condenser sheets including:   a first condenser sheet in which ridges of a first corrugated structure having a first light-condensing characteristic are periodically arranged on one surface of the first condenser sheet in a longitudinal direction of the liquid crystal display panel; and   a second condenser sheet in which ridges of a second corrugated structure having a second light-condensing characteristic are periodically arranged on one surface of the second condenser sheet in a lateral direction of the liquid crystal display panel,   wherein, when a longitudinal, lateral, or sub-pixel pitch of the liquid crystal display panel is defined as Pp, an array pitch of the first corrugated structure is defined as Px, and an array pitch of the second corrugated structure is defined as Py, the following relationships are satisfied: Px is approximately equal to Pp/(14−0.045Pp) and Py is approximately equal to Pp/(11.5−0.032Pp) such that moiré patterns are not produced by the condenser sheets and the liquid crystal display panel, and the condenser sheets do not significantly reduce the luminance from the liquid crystal display.   
     
     
       2. The liquid crystal display apparatus according to  claim 1 , wherein each of the first and second corrugated structures is a prism structure having ridges of a triangular shape in cross section. 
     
     
       3. The liquid crystal display apparatus according to  claim 1 , wherein at least one of the ridges of the first corrugated structure or the ridges of the second corrugated structure have a shape of an aspheric lens. 
     
     
       4. The liquid crystal display apparatus according to  claim 1 , wherein Px≤50, Py≤50, and |Px−Py|<50 are satisfied when Pp≥222. 
     
     
       5. The liquid crystal display apparatus according to  claim 1 , wherein Px≤20, Py≤20, and |Px−Py|<20 are satisfied when 222>Pp≥144. 
     
     
       6. The liquid crystal display apparatus according to  claim 1 , wherein Px≤15, Py≤20, and −20<Px−Py<15 are satisfied when 114>Pp≥136.5. 
     
     
       7. The liquid crystal display apparatus according to  claim 1 , wherein Px is slightly less than or equal to Pp/(14−0.045Pp) and Py is slightly less than or equal to Pp/(11.5−0.032Pp). 
     
     
       8. A liquid crystal display apparatus comprising:
 a liquid crystal display panel; and   condenser sheets for condensing light emitted from a light source and guiding the light toward the liquid crystal display panel,   the condenser sheets including:   a first condenser sheet in which ridges of a first corrugated structure having a first light-condensing characteristic are periodically arranged on one surface of the first condenser sheet in a longitudinal direction of the liquid crystal display panel; and   a second condenser sheet in which ridges of a second corrugated structure having a second light-condensing characteristic are periodically arranged on one surface of the second condenser sheet in a lateral direction of the liquid crystal display panel,   wherein, when a longitudinal, lateral, or sub-pixel pitch of the liquid crystal display panel is defined as Pp, an array pitch of the first corrugated structure is defined as Px, and an array pitch of the second corrugated structure is defined as Py, the following relationships are satisfied: Px is approximately equal to Pp/(14−0.045Pp) and Py is approximately equal to Pp/(11.5−0.032Pp) such that moiré patterns are not produced by the condenser sheets and the liquid crystal display panel, and the condenser sheets do not significantly reduce the luminance from the liquid crystal display.   
     
     
       9. The liquid crystal display apparatus according to  claim 8  incorporated in a device selected from the following group: a mobile phone, a digital camera, a liquid crystal television. 
     
     
       10. The liquid crystal display apparatus according to  claim 8 , wherein each of the first and second corrugated structures is a prism structure having ridges of a triangular shape in cross section. 
     
     
       11. The liquid crystal display apparatus according to  claim 8 , wherein at least one of the ridges of the first corrugated structure or the ridges of the second corrugated structure have a shape of an aspheric lens. 
     
     
       12. The liquid crystal display apparatus according to  claim 8 , wherein Px≤50, Py≤50, and |Px−Py|<50 are satisfied when Pp≥222. 
     
     
       13. The liquid crystal display apparatus according to  claim 8 , wherein Px≤20, Py≤20, and |Px−Py|<20 are satisfied when 222>Pp≥144. 
     
     
       14. The liquid crystal display apparatus according to  claim 8 , Wherein Px≤15, Py≤20, and −20<Px−Py<15 are satisfied when 114>Pp≥136.5. 
     
     
       15. The liquid crystal display apparatus according to  claim 8 , wherein Px is slightly less than or equal to Pp/(14−0.045Pp) and Py is slightly less than or equal to Pp/(11.5−0.032Pp). 
     
     
       16. A liquid crystal display apparatus comprising:
 a light source;   a liquid crystal display panel;   and condenser sheets for condensing light emitted from the light source and guiding the light toward the liquid crystal display panel,   the condenser sheets including:   a first condenser sheet in which ridges of a first corrugated structure having a first light-condensing characteristic are periodically arranged on one surface of the first condenser sheet in a longitudinal direction of the liquid crystal display panel; and   a second condenser sheet in which ridges of a second corrugated structure having a second light-condensing characteristic are periodically arranged on one surface of the second condenser sheet in a lateral direction of the liquid crystal display panel,   wherein, when a pixel pitch of the liquid crystal display panel is defined as Pp, an array pitch of the first corrugated structure is defined as Px, and an array pitch of the second corrugated structure is defined as Py, the following relationships are satisfied: 10 μm≤Px≤Pp/(14−0.045Pp), and 10 μm≤Py≤Pp/(11.5−0.032Pp) such that moiré patterns are not produced by the condenser sheets and the liquid crystal display panel, and the condenser sheets do not significantly reduce the luminance from the liquid crystal display.   
     
     
       17. The liquid crystal display apparatus according to claim 16, wherein each of the first and second corrugated structures is a prism structure having ridges of a triangular shape in cross section. 
     
     
       18. The liquid crystal display apparatus according to claim 16, wherein at least one of the ridges of the first corrugated structure or the ridges of the second corrugated structure have a shape of an aspheric lens. 
     
     
       19. A liquid crystal display apparatus comprising:
 a liquid crystal display panel; and   condenser sheets for condensing light emitted from a light source and guiding the light toward the liquid crystal display panel,   the condenser sheets including:   a first condenser sheet in which ridges of a first corrugated structure having a first light-condensing characteristic are periodically arranged on one surface of the first condenser sheet in a longitudinal direction of the liquid crystal display panel; and   a second condenser sheet in which ridges of a second corrugated structure having a second light-condensing characteristic are periodically arranged on one surface of the second condenser sheet in a lateral direction of the liquid crystal display panel,   wherein, when a pixel pitch of the liquid crystal display panel is defined as Pp, an array pitch of the first corrugated structure is defined as Px, and an array pitch of the second corrugated structure is defined as Py, the following relationships are satisfied: 10 μm≤Px≤Pp/(14−0.045Pp), 10 μm≤Py≤Pp/(11.5−0.032Pp) such that moiré patterns are not produced by the condenser sheets and the liquid crystal display panel, and the condenser sheets do not significantly reduce the luminance from the liquid crystal display.   
     
     
       20. The liquid crystal display apparatus according to claim 19 incorporated in a device selected from the following group: a mobile phone, a digital camera, a liquid crystal television. 
     
     
       21. The liquid crystal display apparatus according to claim 19, wherein each of the first and second corrugated structures is a prism structure having ridges of a triangular shape in cross section. 
     
     
       22. The liquid crystal display apparatus according to claim 19, wherein at least one of the ridges of the first corrugated structure or the ridges of the second corrugated structure have a shape of an aspheric lens. 
     
     
       23. A liquid crystal display apparatus comprising:
 a light source;   a liquid crystal display panel; and   condenser sheets for condensing light emitted from the light source and guiding the light toward the liquid crystal display panel,   the condenser sheets including;   a first condenser sheet in which ridges of a first corrugated structure having a first light-condensing characteristic are periodically arranged on one surface of the first condenser sheet in a first direction of the liquid crystal display panel; and   a second condenser sheet in which ridges of a second corrugated structure having a second light-condensing characteristic are periodically arranged on one surface of the second condenser sheet in a second direction of the liquid crystal display panel, wherein the first direction and the second direction are crossed,   wherein, a pixel pitch of the liquid crystal display panel in micrometers is defined as Pp, an array pitch of the first corrugated structure in micrometers is defined as Px and has a value greater than or equal to 10 μm and less than or equal to Pp/(14−0.045Pp), and an array pitch of the second corrugated structure in micrometers is defined as Py and has a value greater than or equal to 10 μm and less than or equal to Pp/(11.5−0.032Pp).   
     
     
       24. The liquid crystal display apparatus according to claim 23, wherein the second direction is oriented orthogonally to the first direction. 
     
     
       25. The liquid crystal display apparatus according to claim 23, wherein the first direction is along a longitudinal direction of the liquid crystal display panel. 
     
     
       26. The liquid crystal display apparatus according to claim 23, wherein the second direction is along a lateral direction of the liquid crystal display panel. 
     
     
       27. The liquid crystal display apparatus according to claim 23, wherein each of the first and second corrugated structures is a prism structure having ridges of a triangular shape in cross section. 
     
     
       28. The liquid crystal display apparatus according to claim 23, wherein:
 each of the first and second corrugated structures is a prism structure having ridges of a triangular shape in cross section; and   the vertex angle of the prism structures having ridges of a triangular shape in cross section in the first corrugated structure are different from the vertex angle of the prism structures having ridges of a triangular shape in cross section in the second corrugated structure.   
     
     
       29. The liquid crystal display apparatus according to claim 23, wherein at least one of the ridges of the first corrugated structure or the ridges of the second corrugated structure have a shape of an aspheric lens. 
     
     
       30. The liquid crystal display apparatus according to claim 23, wherein at least one of the first corrugated structure and second corrugated structure is on a surface of a base film made of light-transmissive resin. 
     
     
       31. The liquid crystal display apparatus according to claim 23, wherein the base film is selected from polyethylene terephthalate (PET) or polycarbonate (PC). 
     
     
       32. The liquid crystal display apparatus according to claim 23, wherein the first condenser sheet and second condenser sheet are bonded together with an adhesive layer. 
     
     
       33. The liquid crystal display apparatus according to claim 23, wherein the adhesive layer is made of a material having a refractive index lower than the first condenser sheet and second condenser sheet. 
     
     
       34. The liquid crystal display apparatus according to claim 23, the adhesive layer is formed of an acrylic ultraviolet-curable resin having a refractive index of from 1.3 to 1.4. 
     
     
       35. The liquid crystal display apparatus according to claim 23, further comprising a diffusion plate. 
     
     
       36. The liquid crystal display apparatus according to claim 23, wherein the diffusion plate is arranged between the condenser sheet and the light source. 
     
     
       37. The liquid crystal display apparatus according to claim 23, wherein the diffusion plate is arranged between the condenser sheet and the liquid crystal display panel. 
     
     
       38. The liquid crystal display apparatus according to claim 23, wherein the array pitch of the first corrugated structure arranged in the longitudinal direction is set to one-third of the array pitch of the second corrugated structure arranged in the lateral direction. 
     
     
       39. The liquid crystal display apparatus according to claim 23, wherein the apparatus is further configured such that 50 μm≥Px≥14 μm, 50 μm≥Py≥14 μm, Px≤Pp/(14−0.045Pp) and Py≤Pp/(11.5−0.032Pp). 
     
     
       40. The liquid crystal display apparatus according to claim 23, wherein the apparatus is further configured such that 50 μm≥Py≥14 μm and Py≤Pp/(11.5−0.032Pp). 
     
     
       41. The liquid crystal display apparatus according to claim 23, wherein Pp=222 μm. 
     
     
       42. The liquid crystal display apparatus according to claim 23, wherein Pp=144 μm. 
     
     
       43. The liquid crystal display apparatus according to claim 23, wherein Pp=136.5 μm.