LCD with hetero polar light guide

• US 7,379,130 B1
• Filed: 10/03/2007
• Issued: 05/27/2008
• Est. Priority Date: 10/03/2007
• Status: Active Grant

• Current Assignee: Viterra Incorporated (Glencore Plc)
• Original Assignee: Viterra Incorporated (Glencore Plc)
• Inventors: Bhalla, Jagmohan
• Primary Examiner(s): Nelms; David
• Assistant Examiner(s): Lawson; Matthew P
• Application Number:
  US11/866,846
• Time in Patent Office: 237 Days
• Field of Search: 349/15, 349/61, 349/62, 349/73
• US Class Current: 349/61
• 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 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one

Abstract

An electro-optical display includes a light source and a Polarization Separation Element (“PSE”) coupled to the light source. The PSE generates a first output having a first polarization state and a second output having a second polarization state. The display further includes a Hetero Polar Light Guide (“HPLG”) that includes a first region optically isolated from a second region and coupled to the PSE. The first output of the PSE is directed into the first region and the second output of the PSE is directed into the second region, and the first region and second region output light in substantially the same direction.

Claims

1. An electro-optical system comprising:

a light source;

a Hetero Polar Light Guide (HPLG) coupled to the light source and having a first region and a second region, wherein the first region outputs a first light substantially comprising a first polarization state, and the second region outputs a second light substantially comprising a second polarization state, wherein the first light and the second light is output in approximately the same direction and the first polarization state is different than the second polarization state; and

a polarization modifying light intensity modulation layer coupled to the hetero polar light guide having a third region and a fourth region;

wherein the third region accepts polarized light aligned in a first direction and the fourth region accepts polarized light aligned in a second direction; and

the third region is substantially aligned with and approximately the same shape and size as the first region, and said fourth region is substantially aligned with and approximately the same shape and size as the second region.

2. The electro-optical system of claim 1, further comprising:

a Polarization Separation Element (PSE) coupled to the light source, the PSE adapted to receive light from the light source and generate a first output substantially comprising the first polarization state and a second output substantially comprising the second polarization state;

wherein the first output is optically coupled to the first region of the HPLG, and the second output is optically coupled to the second region of the HPLG, and the first and second regions of the HPLG are optically isolated to substantially prevent light from traveling between the first and second regions.

3. The electro-optical system of claim 1, wherein the polarization modifying light intensity modulation layer comprises a Liquid Crystal layer.

4. The electro-optical system of claim 2, further comprising a collimator coupled to the light source and adapted to deliver collimated light to the PSE.

5. The electro-optical system of claim 4 wherein the collimator comprises a lens system.

6. The electro-optical system of claim 1, further comprising:

a heterogeneous front polarizer coupled to the light intensity modulation layer and having a fifth region and a sixth region;

wherein the fifth region is substantially aligned with and approximately the same size and shape as the first region and the sixth region is substantially aligned with and approximately the same size and shape as the second region.

7. The electro-optical system of claim 6, wherein the electro-optical system operates as a Hetero Polar Liquid Crystal Display (HPLCD).

8. The electro-optical system of claim 1, further comprising:

a heterogeneous rear polarizer coupled to the light intensity modulation layer and having a seventh region and an eighth region;

wherein the seventh region is substantially aligned with and approximately the same size and shape as the first region and the eighth region is substantially aligned with and approximately the same size and shape as the second region.

9. The electro-optical system of claim 8, wherein the heterogeneous rear polarizer is reflective and the seventh region transmits the first polarization state and reflects the second polarization state, and the eighth region transmits the second polarization state and reflects the first polarization state.

10. The electro-optical system of claim 6, further comprising:

a heterogeneous rear polarizer coupled to the light intensity modulation layer and having a ninth region and an tenth region;

wherein the ninth region is substantially aligned with and approximately the same size and shape as the first region, and the tenth region is substantially aligned with and approximately the same size and shape as the second region.

11. The electro-optical system of claim 10, wherein the heterogeneous rear polarizer is reflective and the ninth region transmits the first polarization state and reflects the second polarization state, and the tenth region transmits the second polarization state and reflects the first polarization state.

12. The electro-optical system of claim 10, wherein the electro-optical system operates as a Hetero Polar Liquid Crystal Display (HPLCD).

13. The electro-optical system of claim 1, wherein the first polarization state is orthogonal to the second polarization state and the first direction is orthogonal to the second direction.

14. The electro-optical system of claim 1, wherein the first region selectively extracts by out-coupling the first polarization state;

and

the second region selectively extracts by out-coupling the second polarization.

15. The electro-optical system of claim 14, wherein the polarization selective out-coupling comprises an anisotropic polymer dispersed liquid crystal (PDLC) layer.

16. A method of operating an electro-optical display device comprising:

generating light;

coupling the light to a Hetero Polar Light Guide (HPLG) having a first region and a second region, wherein the first and second regions of the HPLG are optically isolated to substantially prevent light from traveling between the regions;

enabling the first region to output light of substantially a first polarization state and the second region to output light of substantially a second polarization state that is different from the first polarization state, wherein light of both first and second polarization states is output in substantially a same direction; and

coupling the light from the HPLG to a Liquid Crystal (LC) light intensity modulation layer having a third region and a fourth region and liquid crystal molecules;

wherein the third region molecules are aligned in a first direction and the fourth region molecules are aligned in a second direction; and

the third region is substantially aligned with and approximately the same shape and size as the first region, and the fourth region is substantially aligned with and approximately the same shape and size as the second region; and

coupling an output from the LC light intensity modulation layer to a heterogeneous front polarizer having a fifth region and a sixth region, wherein the fifth region is substantially aligned with and approximately the same size and shape as the first region, and the sixth region is substantially aligned with and approximately the same size and shape as the second region.

17. The method of claim 16, further comprising:

coupling the light to a Polarization Separation Element (PSE) that produces a first output having the substantially first polarization state and a second output having the substantially second polarization state;

wherein the first output is optically coupled to the first region of the HPLG and the second output is optically coupled to the second region of the HPLG.

18. The method of claim 16, further comprising:

a heterogeneous rear polarizer having a ninth region and an tenth region;

wherein the ninth region is substantially aligned with and approximately the same size and shape as the first region; and

the tenth region is substantially aligned with and approximately the same size and shape as the second region; and

light from the HPLG is coupled to the heterogeneous rear polarizer, which outputs light to the LC light intensity modulation layer.

19. The method of claim 16, wherein the first region selectively out-couples the first polarization state light and the second region selectively out-couples the second polarization state light.

20. A liquid crystal display (LCD) comprising:

a light source;

a Polarization Separation Element (PSE) coupled to the light source and adapted to generate a first output having a first polarization state and a second output having a second polarization state; and

an Hetero Polar Light Guide (HPLG) coupled to the PSE and comprising a first region optically isolated from a second region;

wherein the first output is directed into the first region and the second output is directed into the second region, and the first region and second region output light in substantially the same direction.