Optical film assembly, as well as backlight module and LCD apparatus comprising the same

• US 7,688,395 B2
• Filed: 10/22/2007
• Issued: 03/30/2010
• Est. Priority Date: 02/09/2007
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Yang, Tun-Chun, Hu, Chih-Jen
• Primary Examiner(s): Font; Frank G
• Assistant Examiner(s): WONG, ERIC K
• Application Number:
  US11/876,253
• Publication Number:
  US 20080192502A1
• Time in Patent Office: 890 Days
• Field of Search: 349/65, 349/96, 349/57
• US Class Current: 349/57
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0056 for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses

Abstract

An optical film for use in backlight module is provided. The optical provides quality luminance of a liquid crystal display (LCD) apparatus. The optical film assembly comprises a substrate with a polarization direction, in which the substrate has a first surface and a second surface opposing thereto. A first prismatic structure is formed on the first surface. The polarization direction of the substrate defines the first angle θ₁ with respect to the configured direction of the first prismatic structure, in which 0°<θ₁<180°.

Claims

1. An optical film assembly, comprising:

a substrate with a polarization direction, which comprises a first surface and a second surface opposing thereto; and

a first prismatic structure which is formed on the first surface with a certain configured direction, wherein the configured direction of the first prismatic structure defines a first angle θ

₁ with respect to the polarization direction of the substrate, in which 0°

<

θ

₁<

180°

.

2. The optical film assembly of claim 1, wherein the first angle θ

₁ is between 5° and

175°

.

3. The optical film assembly of claim 1, further comprising a brightness enhancement film (BEF) which is deposited under the substrate and faces the second surface.

4. The optical film assembly of claim 3, further comprising a second prismatic structure which is formed on the brightness enhancement film (BEF), thereby the second prismatic structure facing the second surface.

5. The optical film assembly of claim 4, wherein the second prismatic structure is in a certain configured direction, which defines a second angle θ

₂ with respect to the polarization direction, in which 0°

<

θ

₁<

180°

.

6. The optical film assembly of claim 5, wherein the configured direction of the first prismatic structure and the configured direction of the second prismatic structure substantially form an included angle of 90°

.

7. The optical film assembly of claim 1, further comprising a second prismatic structure formed on the second surface.

8. The optical film assembly of claim 7, wherein the second prismatic structure is in a certain configured direction, which defines a second angle θ

₂ with respect to the polarization direction, in which 0°

<

θ

₁<

180°

.

9. The optical film assembly of claim 8, wherein the configured direction of the first prismatic structure and the configured direction of the second prismatic structure substantially form an included angle of 90°

.

10. The optical film assembly of claim 1, wherein the substrate comprises a material selected from a group consisting of:

polycarbonate, polysulfonate, polystyrene, polyvinyl chloride, polyvinyl alcohol, polyester, polyethylene terephthalate, polyethylene naphthalate, and a combination of any forgoing materials.

11. A backlight module, comprising:

an optical film assembly of any one of claims 1 to 10;

a diffusion layer deposited under the optical film assembly; and

a light guide plate (LGP) deposited under the diffusion layer.

12. A liquid crystal display (LCD) apparatus, comprising:

a liquid crystal display (LCD) panel;

an optical film assembly of any one of claims 1 to 10 deposited under the liquid crystal display (LCD) panel;

a diffusion layer deposited under the optical film assembly;

a light guide plate (LGP) deposited under the diffusion layer; and

a light source for providing light to the light guide plate (LGP).