ZScreen.RTM. modulator with wire grid polarizer for stereoscopic projection

• US 20080316375A1
• Filed: 06/20/2007
• Published: 12/25/2008
• Est. Priority Date: 06/20/2007
• Status: Active Grant

• Current Assignee: RealD Incorporated
• Original Assignee: Real D
• Inventors: Lipton, Lenny, Cowan, Matt
• Granted Patent: US 7,633,666 B2
• Time in Patent Office: Days
• US Class Current: 349/7
• CPC Class Codes: G02B 27/286 for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34
• CPC Class Codes: G02B 30/25 using polarisation techniques
• CPC Class Codes: G02B 5/3058 comprising electrically conductive elements, e.g. wire grids, conductive particles
• CPC Class Codes: G03B 35/26 using polarised or coloured light separating different viewpoint images

Abstract

A projection design configured for use with a projector having a projector lens is provided. The device includes at least one pi-cell or pi-cell electro-optical modulator in combination with a wire grid polarizer mounted proximate the pi-cell(s). The design may include a cleanup polarizer between the pi-cell(s) and the wire grid polarizer and optionally a protective window between the wire grid projector and projection lens. The device may be oriented at an angle substantially differing from the axis of the projector lens. The resultant device includes spacing for airflow and can offer improved performance, particularly in heating, over designs previously available.

Claims

1. A stereoscopic polarization modulator device configured for use with a projector having a projector lens, the device comprising:

at least one pi-cell; and

a wire grid polarizer mounted proximate at least one pi-cell.

2. The device of claim 1, wherein each pi-cell is proximate another pi cell, and the wire grid polarizer is positioned between one pi-cell and the projector lens.

3. The device of claim 2, further comprising a cleanup polarizer positioned between the at least one pi-cell and the wire grid polarizer.

4. The device of claim 2, wherein electrodes on the wire grid polarizer are positioned on a side of the wire grid polarizer closest to the projector lens.

5. The device of claim 3, further comprising a protective window between the wire grid polarizer and the projector lens.

6. The device of claim 3, wherein the at least one pi-cell, cleanup polarizer, and wire grid polarizer have substantially no space therebetween.

7. The device of claim 6, wherein the wire grid polarizer is spaced apart from the protective window and the protective window is spaced apart from the projector lens.

8. The device of claim 1, wherein the projector lens is oriented along a projection axis, and the at least one pi-cell and wire grid polarizer are oriented along a component axis substantially offset from the projection axis.

9. The device of claim 1, further comprising mounting hardware configured to maintain the at least one pi-cell and the wire grid polarizer in an orientation spaced apart from the projector lens.

10. A method of projecting stereoscopic images comprising:

projecting light energy through a projector lens;

receiving the light energy at a wire grid polarizer and transmitting polarized light energy; and

receiving the polarized light energy at least one pi-cell and transmitting resultant light energy.

11. The method of claim 10, wherein polarized light energy from the wire grid polarizer passes to a cleanup polarizer before being received at the at least one pi-cell.

12. The method of claim 10, wherein electrodes on the wire grid polarizer are positioned on a side of the wire grid polarizer closest to the projector lens.

13. The method of claim 11, wherein light energy from the projector lens passes to a protective window before being received by the wire grid polarizer.

14. The method of claim 13, wherein the at least one pi-cell, cleanup polarizer, and wire grid polarizer have substantially no space therebetween.

15. The method of claim 14, wherein the wire grid polarizer is spaced apart from the protective window and the protective window is spaced apart from the projector lens.

16. The method of claim 10, wherein the projector lens is oriented along a projection axis, and the at least one pi-cell and wire grid polarizer are oriented along a component axis substantially offset from the projection axis.

17. The method of claim 10, wherein the at least one pi-cell and the wire grid polarizer are maintained in an orientation spaced apart from the projector lens.

18. A polarization modulator device comprising:

a first pi-cell electro-optical modulator having a first rub direction;

a second pi-cell electro-optical modulator having a second rub direction differing from the first rub direction; and

a wire grid polarizer located proximate at least one of the first pi-cell electro-optical modulator and the second pi-cell electro-optical modulator and configured to receive light energy from a projector lens and transmit polarized light energy to the first pi-cell electro-optical modulator and the second pi-cell electro-optical modulator.

19. The polarization modulator device of claim 18, further comprising a cleanup polarizer positioned between at least one of:

the first pi-cell electro-optical modulator and the second pi-cell electro-optical modulator; and

the wire grid polarizer.

20. The polarization modulator device of claim 18, further comprising a protective window between the wire grid polarizer and the projector lens.