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 condenser sheet for condensing light emitted from a light source and guiding a light toward a liquid crystal display panel having a pitch defined as Pp in micrometers comprising ridges of a first corrugated structure having a first light-condensing characteristic that are periodically arranged on a first surface of the condenser sheet in a first direction of the liquid crystal display panel, wherein the first corrugated structure has an array pitch in micrometers defined as Px such that Px has a value greater than or equal to 10 microns and less than or equal to Pp/(14−0.045Pp). 
     
     
       17. The condenser sheet of claim 16, wherein the first corrugated structure is a prism structure having ridges of a triangular shape in cross section. 
     
     
       18. The condenser sheet of claim 16, wherein the first corrugated structure includes aspheric lens structures. 
     
     
       19. The condenser sheet of claim 16, wherein 10 microns≤Px≤50 microns and Pp≥222 microns. 
     
     
       20. The condenser sheet of claim 16, wherein 10 microns≤Px≤20 microns and Pp≥144 microns. 
     
     
       21. A condenser sheet for condensing light emitted from a light source and guiding a light toward a liquid crystal display panel having a pitch defined as Pp in micrometers comprising ridges of a second corrugated structure having a second light-condensing characteristic that are periodically arranged on a first surface of the condenser sheet in a second direction of the liquid crystal display panel, wherein the second corrugated structure has an array pitch in micrometers defined as Py such that Py has a value greater than or equal to 10 microns and less than or equal to Pp/(11.5−0.032Pp). 
     
     
       22. The condenser sheet of claim 21, wherein the second corrugated structure is a prism structure having ridges of a triangular shape in cross section. 
     
     
       23. The condenser sheet of claim 21, wherein the second corrugated structure includes aspheric lens structures. 
     
     
       24. The condenser sheet of claim 21, wherein 10 microns≤Py≤50 microns and Pp≥222 microns. 
     
     
       25. The condenser sheet of claim 21, wherein 10 microns≤Py≤20 microns and Pp≥144 microns.