DESPECKLING LASER-IMAGE-PROJECTION SYSTEM

• US 20110234985A1
• Filed: 03/26/2010
• Published: 09/29/2011
• Est. Priority Date: 03/26/2010
• Status: Abandoned Application

• Current Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Original Assignee: Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Inventors: Chen, Gang, Ryf, Roland
• Application Number:
  US12/732,504
• Publication Number:
  US 20110234985A1
• Time in Patent Office: Days
• US Class Current: 353/38
• CPC Class Codes: G02B 27/48 Laser speckle optics
• CPC Class Codes: G03B 21/14 Details
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light
• CPC Class Codes: H04N 9/3161 using laser light sources using laser beams scanning the display screen H04N9/3129

Abstract

An optical device for projecting an image is disclosed. In one embodiment, the optical device includes a configurable optical diffuser adapted to produce a diffuse optical beam having a temporally varying pattern of angular divergence. The optical device further includes a plurality of lenslet pairs to shape the diffuse optical beam and a spatial light modulator to spatially modulate the shaped optical beam to project an image.

Claims

1. An optical device for projecting an image, the optical device comprising:

a configurable optical diffuser adapted to produce a diffuse optical beam having a temporally varying pattern of angular divergence;

a fly'"'"'s eye (FE) integrator adapted to shape the diffuse optical beam; and

a spatial light modulator (SLM) adapted to spatially modulate a shaped optical beam produced by the FE integrator to project the image.

2. The invention of claim 1, wherein:

the FE integrator comprises a plurality of lenslet pairs arranged side by side with each other; and

the plurality of lenslet pairs include different lenslet pairs that produce, on the SLM, a superposition of corresponding illuminated regions that is substantially independent of temporal variations introduced by the configurable optical diffuser.

3. The invention of claim 2, wherein the focal lengths of the lenslets in a lenslet pair are substantially matched.

4. The invention of claim 1, wherein the FE integrator comprises one or more lenslet pairs in which opposing faces are parts of a single optical piece.

5. The invention of claim 1, further comprising a pair of crossed cylindrical lenses to produce an optical beam applied to the configurable optical diffuser.

6. The invention of claim 5, wherein the crossed cylindrical lenses of said pair have different focal lengths.

7. The invention of claim 1, wherein the configurable optical diffuser comprises a transmissive liquid-crystal structure adapted to display a dynamically changing light-scattering pattern.

8. The invention of claim 1, wherein the configurable optical diffuser is a transmissive plate adapted for movement with respect to the FE integrator.

9. The invention of claim 1, further comprising a polarization beam splitter (PBS) to couple light from the FE integrator to the spatial light modulator.

10. The invention of claim 1, further comprising an illumination source including one or more lasers adapted to generate light applied to the configurable optical diffuser.

11. The invention of claim 10, wherein the one or more lasers include a first laser adapted to generate light having different angular divergence along at least two different axes orthogonal to the emission axis of the first laser.

12. The invention of claim 1, wherein the configurable optical diffuser is to receive light from a time-division multiplexed source.

13. The invention of claim 1, further comprising a color combiner adapted to direct multicolored light toward the configurable optical diffuser.

14. An optical device for projecting an image, the optical device comprising:

a pair of crossed cylindrical lenses to provide collimated coherent light;

a moveable diffuser to receive the collimated coherent light to produce a diffuse optical beam having a temporally varying pattern of angular divergence; and

a plurality of lenslet pairs arranged side by side with each other and adapted to shape the diffuse optical beam.

15. The invention of claim 14, further comprising a spatial light modulator adapted to receive at least a portion of a shaped optical beam produced the by plurality of lenslet pairs.

16. The invention of claim 15, further comprising a polarization beam splitter adapted to direct at least a portion of the shaped optical beam toward the spatial light modulator.

17. The invention of claim 14, further comprising a light source including at least one coherent light emitter to be optically coupled to the pair of crossed cylindrical lenses.

18. The inventions of claim 14, wherein the plurality of lenslet pairs is configured as a fly'"'"'s eye integrator structure.

19. The invention of claim 14, further comprising a light combiner adapted to direct light to the pair of crossed cylindrical lenses.

20. The invention of claim 14, wherein the plurality of lenslet pairs include at least one pair in which both lenslets have a cylindrical shape.