OPTICAL SHEET AND DISPLAY DEVICE

• US 20080137346A1
• Filed: 12/03/2007
• Published: 06/12/2008
• Est. Priority Date: 12/06/2006
• Status: Active Grant

• Current Assignee: Saturn Licensing LLC (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ohta, Eiji, Yamakita, Shigehiro, Aoki, Makoto, Abiko, Toru
• Granted Patent: US 7,857,471 B2
• Time in Patent Office: Days
• US Class Current: 362/309
• CPC Class Codes: G02B 5/3016 involving passive liquid crystal elements optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528
• 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

An optical sheet and a display device including the optical sheet are disclosed. The optical sheet includes a first lens sheet having a plurality of first three-dimensional structures arrayed to extend to one surface thereof, and a reflective polarizer sheet for transmitting either one of p-polarization component and s-polarization component of incident light and reflecting the other of p-polarization component and s-polarization component of the incident light. Head portions of the first three-dimensional structures are bonded to the reflective polarizer sheet.

Claims

1. An optical sheet comprising:

a first lens sheet having a plurality of first three-dimensional structures arrayed to extend to one surface thereof; and

a reflective polarizer sheet for transmitting either one of p-polarization component and s-polarization component of incident light and reflecting the other of p-polarization component and s-polarization component of the incident light,

wherein head portions of the first three-dimensional structures are bonded to the reflective polarizer sheet.

2. The optical sheet as claimed in claim 1, wherein each of the first three-dimensional structures has a prismatic geometry.

3. The optical sheet as claimed in claim 1, wherein each of the first three-dimensional structures has a hyperbolic or aspherical curved surface in an array direction.

4. The optical sheet as claimed in claim 1, wherein each of the first three-dimensional structures has a plurality of convex portions in the extended or arrayed direction.

5. The optical sheet as claimed in claim 2, wherein each of the first three-dimensional structures in the arrayed direction has a width of not less than 110 μ

m and not more than 500 μ

m.

6. The optical sheet as claimed in claim 2, wherein each of the first three-dimensional structures in the arrayed direction has a width of not less than 110 μ

m and not more than 330 μ

m.

7. The optical sheet as claimed in claim 1, further comprising a bonding layer provided between the first lens sheet and the reflective polarizer sheet,

wherein head portions of the first lens sheet are bonded to the reflective polarizer sheet through the bonding layer.

8. The optical sheet as claimed in claim 1, wherein each of the first three-dimensional structures in the arrayed direction has a bonding width of not more than 20% of the width of the arrayed direction of the first three-dimensional structures.

9. The optical sheet as claimed in claim 1, wherein the reflective polarizer sheet has a stacked structure in which a multi-layered film having different refractive indices between adjacent films each other is held between diffuser films.

10. The optical sheet as claimed in claim 1, wherein the diffuser film has a haze value due to forward scattering different from a haze value due to back scattering.

11. The optical sheet as claimed in claim 10, wherein the diffuse film has the haze value due to the forward scattering which is larger than the haze value due to the back scattering.

12. The optical sheet as claimed in claim 10, further comprising a second lens sheet having a plurality of second three-dimensional structures arrayed to extend to one surface thereof and extend to a direction intersecting with the extended direction of the first three-dimensional structure,

wherein the other surface of the second lens sheet is bonded to an opposite surface of the surface bonded to the first lens sheet of the reflective polarizer sheet.

13. The optical sheet as claimed in claim 12, wherein each of the second three-dimensional structures has a hyperbolic or aspherical curved surface in the arrayed direction.

14. The optical sheet as claimed in claim 12, wherein each of the second three-dimensional structures in the arrayed direction has a width of not more than 50 μ

m.

15. A display device comprising:

a panel driven based on image signals;

a light source emitting light for illuminating the panel; and

an optical sheet provided between the panel and the light source,

wherein the optical sheet has a lens sheet having a plurality of three-dimensional structures arrayed to extend to one surface thereof, and a reflective polarizer sheet for transmitting either one of p-polarization component and s-polarization component of incident light and reflecting the other of p-polarization component and s-polarization component of the incident light, head portions of the three-dimensional structures being bonded to the reflective polarizer sheet.