Prism sheet with curved surface and liquid crystal display device using same

• US 8,558,969 B2
• Filed: 08/04/2008
• Issued: 10/15/2013
• Est. Priority Date: 08/03/2007
• Status: Active Grant

• Current Assignee: InnoLux Corporation
• Original Assignee: Chi Mei Innolux Corporation (InnoLux Corporation), Innocom Technology (Shenzhen) Co., Ltd. (InnoLux Corporation)
• Inventors: Xu, Yi, Lin, Ching-Huang
• Primary Examiner(s): Robinson, Mark
• Assistant Examiner(s): BLEVINS, JERRY M
• Application Number:
  US12/221,631
• Publication Number:
  US 20090033831A1
• Time in Patent Office: 1,898 Days
• Field of Search: 349/57, 349 62- 65, 359/831, 362/608, 362/620, 362/626
• US Class Current: 349/64
• CPC Class Codes: G02B 5/0221 the surface having an irregular structure G02B5/0226 takes precedence
• 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 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02B 6/0043 provided on the surface of the light guide

Abstract

An exemplary prism sheet includes a base including an upper surface and a plurality of lenses disposed on the upper surface. The upper surface is a wavy surface. A liquid crystal display device using the prism sheet is also provided.

Claims

1. A prism sheet, comprising:

a base comprising an upper surface; and

a plurality of lenses disposed on the upper surface;

wherein in a cross-section of the prism sheet, the upper surface is a continuous curve having a plurality of wave crests in different sizes and a plurality of wave troughs in different sizes;

wherein the upper surface is wavy along a first direction and extends out linearly in a second direction, the first direction being perpendicular to the second direction;

wherein the plurality of lenses form a serrated surface along the first direction and extend out linearly in the second direction, and each of the plurality of lenses is a long straight column having a triangular cross-section being parallel to each other.

2. The prism sheet of claim 1, wherein a distance defined between the centers of each pair of adjacent lenses is different.

3. The prism sheet of claim 1, wherein the lenses are arranged according to the upper surface to form a corresponding wave surface along the first direction.

4. A liquid crystal display device, comprising:

a display panel; and

a backlight module opposite to the display panel, the backlight module comprising;

a prism sheet comprising a base and a plurality of lenses, the base comprising an upper surface, and the plurality of lenses are positioned on the upper surface;

wherein in a cross-section of the prism sheet, the upper surface is a continuous curve having a plurality of wave crests in different sizes and a plurality of wave troughs in different sizes, the upper surface is wavy along a first direction and extends out linearly in a second direction, the first direction being perpendicular to the second direction;

wherein the plurality of lenses form a serrated surface along the first direction and extend out linearly in the second direction, and each of the plurality of lenses is a long straight column having a triangular cross-section being parallel to each other.

5. The liquid crystal display device of claim 4, wherein the waviness along the first direction corresponding to the successive curve having the plurality of wave crests in different sizes and the plurality of wave troughs in different sizes.

6. The liquid crystal display device of claim 5, wherein the plurality of lenses are arranged according to the upper surface such that top edges of the lenses cooperatively define a wave surface along the first direction, the wave surface corresponding to the waviness of the upper surface along the first direction.

7. The liquid crystal display device of claim 6, wherein a distance defined between the centers of each pair of adjacent lenses is different.

8. The liquid crystal display device of claim 4, wherein the base further comprises a lower surface, the lower surface comprising a plurality of micro cavities.

9. The liquid crystal display device of claim 8, wherein the micro cavities are uniformly distributed.

10. The liquid crystal display device of claim 4, wherein pitches between adjacent wave crests are nonuniform.

11. A prism sheet, comprising:

a base comprising an upper surface; and

a plurality of lenses disposed on the upper surface;

wherein in a cross-section of the prism sheet, the upper surface is a continuous curve having a plurality of wave crests in different sizes and a plurality of wave troughs in different sizes, and heights of at least two of the wave troughs are different from each other;

wherein the upper surface is wavy along a first direction and extends out linearly in a second direction, the first direction being perpendicular to the second direction;

wherein the plurality of lenses form a serrated surface along the first direction and extend out linearly in the second direction, and each of the plurality of lenses is a long straight column having a triangular cross-section being parallel to each other.

12. A liquid crystal display device, comprising:

a display panel; and

a backlight module opposite to the display panel, the backlight module comprising;

a prism sheet comprising a base and a plurality of lenses, the base comprising an upper surface, and the plurality of lenses are positioned on the upper surface;

wherein in a cross-section of the prism sheet, the upper surface is a continuous curve having a plurality of wave crests in different sizes and a plurality of wave troughs in different sizes, the upper surface is wavy along a first direction, and the lenses form a serrated surface along the first direction;

wherein the base further comprises a lower surface, the lower surface comprising a plurality of uniformly distributed micro cavities;

wherein the upper surface is wavy along a first direction and extends out linearly in a second direction, the first direction being perpendicular to the second direction;

wherein the plurality of lenses form a serrated surface along the first direction and extend out linearly in the second direction, and each of the plurality of lenses is a long straight column having a triangular cross-section being parallel to each other.

13. A liquid crystal display device, comprising:

a display panel; and

a backlight module opposite to the display panel, the backlight module comprising;

a prism sheet comprising a base and a plurality of lenses, the base comprising an upper surface, and the lenses positioned on the upper surface;

wherein in a cross-section of the prism sheet, the upper surface is a continuous curve having a plurality of wave crests in different sizes and a plurality of wave troughs in different sizes, the upper surface is wavy along a first direction, and the lenses form a serrated surface along the first direction;

wherein heights as measured between tops of the wave crests and bottoms of the wave troughs are non-uniform;

wherein the upper surface is wavy along a first direction and extends out linearly in a second direction, the first direction being perpendicular to the second direction;

wherein the plurality of lenses form a serrated surface along the first direction and extend out linearly in the second direction, and each of the plurality of lenses is a long straight column having a triangular cross-section being parallel to each other.