PRISM SHEET AND LIQUID CRYSTAL DISPLAY DEVICE USING THE SAME

• US 20090046370A1
• Filed: 11/29/2007
• Published: 02/19/2009
• Est. Priority Date: 08/13/2007
• Status: Active Grant

• Current Assignee: Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hon Hai Precision Industry Co., Ltd.
• Inventors: CHANG, SHAO-HAN
• Granted Patent: US 7,695,152 B2
• Time in Patent Office: Days
• US Class Current: 359/625
• CPC Class Codes: G02B 5/0231 the surface having microprismatic or micropyramidal shape macroscopic prism arrays G02B5/045
• CPC Class Codes: G02B 5/0278 used in transmission
• CPC Class Codes: G02B 5/045 Prism arrays

Abstract

An exemplary prism sheet includes a light input surface, a light output surface opposite to the light input surface, and a plurality of triangular pyramidal micro-elements and a plurality of hexagonal pyramidal micro-elements. The triangular pyramidal micro-elements and the hexagonal pyramidal micro-elements are formed on the light output surface. Each triangular pyramidal micro-element surrounded by three adjacent hexagonal pyramidal micro-elements. Bottom surfaces of each hexagonal pyramidal micro-element and each triangular pyramidal micro-element are coplanar with the light output surface. A liquid crystal display device using the prism sheet is also provided.

Claims

1. A prism sheet, comprising:

a light input surface;

a light output surface opposite to the light input surface; and

a plurality of triangular pyramidal micro-elements and a plurality of hexagonal pyramidal micro-elements formed on the light output surface, wherein each triangular pyramidal micro-element is surrounded by three adjacent hexagonal pyramidal micro-elements, bottom surfaces of each hexagonal pyramidal micro-element and each triangular pyramidal micro-element are coplanar with the light output surface.

2. The prism sheet as claimed in claim 1, wherein at least one of the triangular pyramidal micro-elements and the hexagonal pyramidal micro-elements protrudes from the light output surface.

3. The prism sheet as claimed in claim 1, wherein at least one of the triangular pyramidal micro-elements and the hexagonal pyramidal micro-elements is a depression in the light output surface.

4. The prism sheet as claimed in claim 1, wherein the triangular pyramidal micro-elements are protrusions and the hexagonal pyramidal micro-elements are depressions.

5. The prism sheet as claimed in claim 1, wherein a pitch of adjacent centers of triangular pyramidal micro-elements is configured to be in a range from about 0.0125 millimeters to about 0.05 millimeters.

6. The prism sheet as claimed in claim 1, wherein a dihedral angle defined by opposite side surfaces of each hexagonal pyramidal micro-element is in a range from about 60 degrees to about 120 degrees.

7. The prism sheet as claimed in claim 1, wherein a material of the prism sheet is selected from the group consisting of polycarbonate, polymethyl methacrylate, polystyrene, copolymer of methylmethacrylate and styrene, and any suitable combination thereof.

8. The prism sheet as claimed in claim 1, wherein a thickness of the prism sheet is in a range from about 3 millimeters to about 5 millimeters.

9. A liquid crystal display device comprising:

at least one light source;

a light diffusion plate positioned above the at least one light source;

a prism sheet positioned above the light diffusion plate, the prism sheet comprising;

a light input surface;

a light output surface opposite to the light input surface; and

a plurality of triangular pyramidal micro-elements and hexagonal pyramidal micro-elements formed on the light output surface, wherein each triangular pyramidal micro-element is surrounded by three adjacent hexagonal pyramidal micro-elements, bottom surfaces of each hexagonal pyramidal micro-element and each triangular pyramidal micro-element are coplanar with the light output surface; and

a liquid crystal display panel positioned above the prism sheet.

10. The liquid crystal display device as claimed in claim 9, further comprising a housing, the light source being positioned in the housing.

11. The liquid crystal display device as claimed in claim 9, wherein at least one of the triangular pyramidal micro-elements and the hexagonal pyramidal micro-elements is protrusion protruding from the light output surface.

12. The liquid crystal display device as claimed in claim 9, wherein at least one of the triangular pyramidal micro-elements and the hexagonal pyramidal micro-elements is depression depressed inward from the light output surface.

13. The liquid crystal display device as claimed in claim 9, wherein the triangular pyramidal micro-elements are protrusions and the hexagonal pyramidal micro-elements are depressions.

14. The liquid crystal display device as claimed in claim 9, wherein a pitch of adjacent centers of adjacent triangular pyramidal micro-elements is in a range from about 0.0125 millimeters to about 0.05 millimeters.

15. The liquid crystal display device as claimed in claim 9, wherein a dihedral angle defined by opposite side surfaces of each hexagonal pyramidal micro-element is in a range from about 60 degrees to about 120 degrees.

16. The liquid crystal display device as claimed in claim 9, wherein a thickness of the prism sheet is in the range from about 3 millimeters to about 5 millimeters.