Differential interferometric light modulator and image display system

• US 7,277,216 B2
• Filed: 08/03/2005
• Issued: 10/02/2007
• Est. Priority Date: 11/26/2004
• Status: Active Grant

• Current Assignee: Mantis Vision, Ltd.
• Original Assignee: Alces Technology, Inc. (Mantis Vision, Ltd.)
• Inventors: Bloom, David M.
• Primary Examiner(s): Sugarman; Scott J.
• Application Number:
  US11/161,452
• Publication Number:
  US 20060114543A1
• Time in Patent Office: 790 Days
• Field of Search: 359/291, 359/276, 359/279
• US Class Current: 359/276
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G02B 26/06 for controlling the phase of light G02B26/08 takes precedence , measuring optical phase difference G01J9/00
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 27/281 used for attenuating light intensity, e.g. comprising rotatable polarising elements
• CPC Class Codes: G02F 1/21 by interference

Abstract

A differential interferometric light modulator and image display system comprises a polarizing beam splitter, a polarization displacement device and a linear array of MEMS optical phase shifting devices to modulate a line image. The polarizing beam splitter acts as both the polarizer and the analyzer in an interferometer. The polarization displacement device divides polarized light from a polarizer into orthogonal polarization components which propagate parallel to one another. The MEMS optical phase shifting device array imparts a relative phase shift onto the polarization components and returns them to the polarization displacement device where they are recombined and sent to the analyzer. The MEMS optical phase shifting devices are electronically controlled and convert electronic image data into actual light modulation.

Claims

1. An image display system comprising:

a polarizing beam splitter;

a polarization displacement device; and

, a MEMS optical phase shifting device;

wherein, polarized light is directed from the polarizing beam splitter to the polarization displacement device;

the polarization displacement device divides the light into parallel beams of orthogonal polarization; and

, the MEMS optical phase shifting device imparts a relative phase shift upon the parallel beams.

2. The system of claim 1 wherein the polarization displacement device comprises:

a birefringent prism that imparts angular separation on orthogonally polarized components of the polarized light; and

, a lens placed such that the polarized components travel parallel to each other between the lens and the MEMS optical phase shifting device.

3. The system of claim 2 wherein the polarization displacement device comprises:

a Wollaston, Rochon, or Senarmont prism; and

, a lens.

4. The system of claim 1 wherein the polarization displacement device comprises:

a walkoff crystal that imparts lateral displacement on orthogonally polarized components of the polarized light.

5. The system of claim 4 wherein the polarization displacement device comprises:

a Savart, or modified Savart, plate.

6. The system of claim 1 wherein the MEMS optical phase shifting device comprises:

a MEMS ribbon device.

7. The system of claim 1 wherein the MEMS optical phase shifting device comprises:

a MEMS cantilever device.

8. The system of claim 1 wherein the MEMS optical phase shifting device comprises:

a MEMS hinge device.

9. An image display system comprising:

two or more differential interferometric light modulators; and

, a color combining prism that combines light from each modulator to form a multicolor line image output.

10. The system of claim 9 further comprising a scanning mirror that scans the line image to form a two-dimensional image.

11. The system of claim 10 further comprising an eyepiece for direct viewing of the two-dimensional image.

12. The system of claim 9 further comprising an object scanned across the line image output.