Light-Transmitting Film, Method of Forming Light-Transmitting Film, and Liquid Crystal Display

• US 20080247192A1
• Filed: 09/14/2006
• Published: 10/09/2008
• Est. Priority Date: 09/15/2005
• Status: Active Grant

• Current Assignee: Saturn Licensing LLC (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Hoshi, Mitsunari, Horii, Akihiro, Mizuno, Hiroshi, Obata, Kei
• Granted Patent: US 7,712,908 B2
• Time in Patent Office: Days
• US Class Current: 362/627
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• 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 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one

Abstract

A light-transmitting film that has a predetermined polarization split function, in addition to a light-collecting function is provided. The index of refraction nx in a prism extension direction and the index of refraction in a prism alignment direction differ from each other. By generating a difference in the indices of refraction in the prism extension direction and the prism alignment direction orthogonal thereto, for the light incident on the light-transmitting film, the polarization component Lx oscillating in the prism extension direction and the polarization component Ly oscillating in the prism alignment direction can have different transmission characteristics. For example, by setting the index of refraction in the prism extension direction greater than the index of refraction in the prism alignment direction (nx>ny), among the light incident on the light-transmitting film, the amount of return light of the polarization component Lx oscillating in the prism extension direction is greater than that of the polarization component Ly oscillating in the prism alignment direction. In this way, not only a light-collecting function, but also a predetermined polarization split function is obtained.

Claims

1. :

A light-transmitting film comprising;

a three-dimensional structure continuously disposed on a first surface,

wherein the index of refraction in an extension direction of the three-dimensional structure and the index of refraction in an alignment direction of the three-dimensional structure differ.

2. :

The light-transmitting film according to claim 1, wherein the index of refraction in the extension direction is greater than the index of refraction in the alignment direction.

3. :

The light-transmitting film according to claim 1, wherein the index of refraction in the alignment direction is greater than the index of refraction in the extension direction.

4. :

The light-transmitting film according to claim 1, wherein the light-transmitting film comprises a resin film stretched in the extension direction of the three-dimensional structure.

5. :

The light-transmitting film according to claim 4, wherein the light-transmitting film comprises a material having a high index of refraction in the extension direction.

6. :

The light-transmitting film according to claim 4, wherein the light-transmitting film comprises a material having a low index of refraction in the extension direction.

7. :

The light-transmitting film according to claim 4, wherein the light-transmitting film comprises a co-polymer selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), a PET-PEN mixture, and a PET-PEN co-polymer.

8. :

The light-transmitting film according to claim 1, wherein the three-dimensional structure is a prism or a lenticular lens.

9. :

A method of forming a light-transmitting film having a three-dimensional structure continuously disposed on a first surface of said light-transmitting film, the method comprising;

forming a resin film having the three-dimensional structure on the first surface; and

stretching the resin film in an extension direction of the three-dimensional structure and generating a difference in the index of refraction in the extension direction of the three-dimensional structure and the index of refraction in an alignment direction of the three-dimensional structure.

10. :

The method of forming a light-transmitting film according to claim 9, wherein the resin film comprises a material having a high index of refraction in the extension direction.

11. :

The method of forming a light-transmitting film according to claim 9, wherein the resin film is constituted of material having a low index of refraction in the extension direction.

12. :

A liquid crystal display apparatus comprising;

a liquid crystal display panel;

a pair of polarizers formed on opposing surfaces of the liquid crystal display panel;

a light source illuminating the liquid crystal display panel; and

a light-transmitting film disposed between the liquid crystal display panel and the light source, the light-transmitting film having a three-dimensional structure disposed continuously on a surface on a light emission side,

wherein the light-transmitting film has different indices of refraction in an extension direction of the three-dimensional structure and in an alignment direction of the three-dimensional structure.

13. :

The liquid crystal display apparatus according to claim 12,

wherein the light-transmitting film is formed so that the index of refraction in the extension direction of the three-dimensional structure is greater than the index of refraction in the alignment direction of the three-dimensional structure, and

wherein the angle formed by the alignment direction of the three-dimensional structure and a light-transmission axis of the polarizer, among the pair of polarizers, disposed on the light incident side of the liquid crystal display panel ranges from 0°

to 45°

.

14. :

The liquid crystal display apparatus according to claim 12,

wherein the light-transmitting film is formed so that the index of refraction in the alignment direction of the three-dimensional structure is greater than the index of refraction in the extension direction of the three-dimensional structure, and

wherein the angle formed by the extension direction of the three-dimensional structure and a light-transmission axis of the polarizer, among the pair of polarizers, disposed on the light incident side of the liquid crystal display panel ranges from 0°

to 45°

.

15. :

The liquid crystal display apparatus according to claim 12, wherein the light-transmitting film comprises a co-polymer selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), a PET-PEN mixture, and a PET-PEN co-polymer.