Brightness enhancement film with protective layer and backlight module and liquid crystal display with same

• US 20070139776A1
• Filed: 12/14/2006
• Published: 06/21/2007
• Est. Priority Date: 12/16/2005
• Status: Active Grant

• Current Assignee: InnoLux Corporation
• Original Assignee: Innolux Display Corporation (InnoLux Corporation)
• Inventors: Meng, Kai, Mai, Che-Kuei
• Granted Patent: US 7,728,921 B2
• Time in Patent Office: Days
• US Class Current: 359/529
• CPC Class Codes: G02B 1/105 Protective coatings
• CPC Class Codes: G02B 1/14 Protective coatings, e.g. hard coatings
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer

Abstract

An exemplary brightness enhancement film (15) includes a main body (154), a plurality of first prism structures (152), a plurality of second prism structures (156), and first and second protective layers (150, 158). The main body includes a first side, and a second side opposite to the first side. The first prism structures are formed at the first side. The second prism structures are formed at the second surface. The first protective layer covers the plurality of first prism structures, and the second protective layer covers the plurality of second prism structures.

Claims

1. A brightness enhancement film comprising:

a main body comprising;

a first side; and

a second side opposite to the first side;

a plurality of first prism structures formed at the first side;

a plurality of second prism structures formed at the second side; and

at least one protective layer covering at least one of the plurality of first prism structures and the plurality of second prism structures.

2. The brightness enhancement film in claim 1, wherein the at least one protective layer is a first protective layer covering the plurality of first prism structures, and a second protective layer covering the plurality of second prism structures.

3. The brightness enhancement film in claim 2, wherein a refraction index of the first prism structures is substantially equal to a refraction index of the second prism structures.

4. The brightness enhancement film in claim 3, wherein a refraction index of the main body is substantially equal to a refraction index of the second prism structures.

5. The brightness enhancement film in claim 4, wherein a refraction index of the first protective layer is smaller than the refraction index of the first prism structures.

6. The brightness enhancement film in claim 5, wherein a refraction index of the second protective layer is greater than the refraction index of the second prism structures.

7. The brightness enhancement film in claim 1, wherein an orientation of the first prism structures is substantially perpendicular to an orientation of the second prism structures.

8. The brightness enhancement film in claim 1, wherein the first prism structures and the second prism structures each comprise a plurality of triangular prisms or generally triangular prisms with rounded apexes.

9. The brightness enhancement film in claim 1, further comprising a polarizing layer provided thereon.

10. The brightness enhancement film in claim 9, further comprising a protective film covering the polarizing layer.

11. The brightness enhancement film in claim 10, further comprising an adhesive layer provided thereon.

12. The brightness enhancement film in claim 1, further comprising a diffusing layer provided thereon.

13. A backlight module comprising:

a light guide plate comprising a light input surface and a light output surface;

a light source adjacent to the light input surface of the light guide plate; and

a brightness enhancement film facing the light output surface of the light guide plate, the brightness enhancement film comprising;

a main body comprising;

a first side; and

a second side opposite to the first side;

a plurality of first prism structures formed at the first side;

a plurality of second prism structures formed at the second side; and

at least one protective layer covering at least one of the plurality of first prism structures and the plurality of second prism structures.

15. The backlight module in claim 13, further comprising a polarizing layer provided thereon.

16. The backlight module in claim 15, further comprising a protective film covering the polarizing layer.

17. The backlight module in claim 16, further comprising an adhesive layer provided thereon.

18. The backlight module in claim 13, further comprising a diffusing layer provided thereon.

14. The backlight module in claim 14, wherein the at least one protective layer is a first protective layer covering the plurality of first prism structures, and a second protective layer covering the plurality of second prism structures.

19. A liquid crystal display comprising:

a liquid crystal panel; and

a backlight module located adjacent to the liquid crystal panel, the backlight module comprising;

a light guide plate comprising a light input surface and a light output surface;

a light source adjacent to the light input surface of the light guide plate; and

a brightness enhancement film facing the light output surface of the light guide plate, the brightness enhancement film comprising;

a main body comprising;

a first side; and

a second side opposite to the first side;

a plurality of first prism structures formed at the first side;

a plurality of second prism structures formed at the second side; and

at least one protective layer covering at least one of the plurality of first prism structures and the plurality of second prism structures.

20. The liquid crystal display in claim 19, wherein the at least one protective layer is a first protective layer covering the plurality of first prism structures, and a second protective layer covering the plurality of second prism structures.