Spatial light modulator array with heat minimization and image enhancement features

• US 7,170,669 B1
• Filed: 09/28/2005
• Issued: 01/30/2007
• Est. Priority Date: 09/28/2005
• Status: Active Grant

• Current Assignee: Anvik Corporation, National Technology & Engineering Solutions Of Sandia LLC (Honeywell International Inc.)
• Original Assignee: Anvik Corporation, Sandia Corporation (Martin Marietta Corporation)
• Inventors: Zemel, Marc, Jain, Kanti, Sweatt, William C.
• Primary Examiner(s): Thompson; Timothy
• Assistant Examiner(s): FANG, JERRY C
• Application Number:
  US11/237,382
• Time in Patent Office: 489 Days
• Field of Search: 359/290, 359/291, 359/223, 359/224, 359/295
• US Class Current: 359/291
• CPC Class Codes: G02B 26/0808 by means of one or more diffracting elements
• CPC Class Codes: G03F 7/70291 Addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid crystal display [LCD] patterning devices

Abstract

An enhanced spatial light modulator (ESLM) array, a microelectronics patterning system and a projection display system using such an ESLM for heat-minimization and resolution enhancement during imaging, and the method for fabricating such an ESLM array. The ESLM array includes, in each individual pixel element, a small pixel mirror (reflective region) and a much larger pixel surround. Each pixel surround includes diffraction-grating regions and resolution-enhancement regions. During imaging, a selected pixel mirror reflects a selected-pixel beamlet into the capture angle of a projection lens, while the diffraction grating of the pixel surround redirects heat-producing unused radiation away from the projection lens. The resolution-enhancement regions of selected pixels provide phase shifts that increase effective modulation-transfer function in imaging. All of the non-selected pixel surrounds redirect all radiation energy away from the projection lens. All elements of the ESLM are fabricated by deposition, patterning, etching and other microelectronic process technologies.

Claims

1. An enhanced spatial light modulator (SLM) array of a multitude of selectable pixel elements, each having physically-definable selected and non-selected modes, each pixel element comprising:

a) an active region having a characteristic physical condition, which, when the pixel is in selected mode, serves to redirect the radiation incident on it to a primary image position which is located to be effective in a primary use; and

b) a passive region having a different characteristic physical condition, which, when the pixel is in selected mode, serves as means to redirect the radiation incident on it to a location other than said primary image position.

2. The enhanced spatial light modulator array according to claim 1, wherein for a selected pixel element in selected mode, said active region is reflective along a primary axis;

and

said passive region for said selected pixel element in selected mode redirects said incident radiation in a secondary direction differing in alignment substantially from said primary axis.

3. The enhanced spatial light modulator array according to claim 2, wherein for each selected pixel element of said SLM array, the active region is small as contrasted to the passive region, and is reflective;

and

said passive region is diffractive, and diffracts a substantial portion of said incident radiation in said secondary direction.

4. The enhanced spatial light modulator array according to claim 1, each pixel element further comprising:

c) an enhancement region, located proximate to said active region, having a physical characteristic which serves to alter the optical characteristics of the radiation redirected from said active region when in selected mode.

5. The enhanced spatial light modulator array according to claim 1, wherein for each pixel element of said SLM array,

the active region is small as contrasted to the passive region, and is reflective;

and

said passive region is a diffraction grating, and diffracts a substantial portion of said incident radiation in said secondary direction.

6. The enhanced spatial light modulator array according to claim 5, wherein for each pixel element of said SLM array,

said passive region is a diffraction grating of the blazed type.

7. The enhanced spatial light modulator array according to claim 5, wherein for each pixel element of said SLM array,

said passive region is a diffraction grating of the surface relief type.

8. The enhanced spatial light modulator array according to claim 5, wherein for each pixel element of said SLM array,

said passive region is a diffraction grating of constant pitch.

9. The enhanced spatial light modulator array according to claim 5, wherein for each pixel element of said SLM array,

said passive region is a diffraction grating of variable pitch.

10. The enhanced spatial light modulator array according to claim 5, wherein for each pixel element of said SLM array,

said means to redirect the incident radiation to other than said primary image position is a diffraction grating with grooves so aligned that the plane of diffracted rays is parallel to the plane of reflection from said active region.

11. The enhanced spatial light modulator array according to claim 5, wherein for each pixel element of said SLM array,

said means to redirect the incident radiation to other than said primary image position is a diffraction grating with grooves so aligned that the plane of diffracted rays is orthogonal to the plane of reflection from said active region.

12. The enhanced spatial light modulator array according to claim 5, wherein for each pixel element of said SLM array,

said means to redirect the incident radiation to other than said primary image position is a diffraction grating with grooves so aligned that the plane of diffracted rays is different from the plane of reflection from said active region.

13. The enhanced spatial light modulator array according to claim 5, wherein:

said means to redirect the radiation incident on the passive region to a location other than said primary image position is a diffraction grating with grooves positioned with grating lines in different directions in differing regions.

14. The enhanced spatial light modulator array according to claim 5, wherein:

said means to redirect the radiation incident on the passive region to a location other than said primary image position is a diffraction grating with grooves so aligned that the plane of some diffracted rays is orthogonal to the plane of reflection from said active region, and with other grooves so aligned that the plane of some diffracted rays is parallel to the plane of reflection from said active region.

15. The enhanced spatial light modulator array of a multitude of selectable pixel elements, each having physically-definable selected and non-selected modes, according to claim 5, wherein:

said means to redirect the radiation incident on the passive region to a location other than said primary image position is a diffraction grating with grooves positioned for a duty cycle approximating 50%.

16. The enhanced spatial light modulator array according to claim 5, wherein:

said means to redirect the radiation incident on the passive region to a location other than said primary image position is a phase shift means so aligned as to, provide a 180 degree phase shift relative to reflected light from said active region.

17. The enhanced spatial light modulator array according to claim 1, wherein:

said SLM array is a micromirror device.

18. The enhanced spatial light modulator array according to claim 1, wherein:

said SLM array is a liquid crystal light modulator device.

19. The enhanced spatial light modulator array according to claim 1, wherein:

said SLM array is a grating light valve device.

20. The enhanced spatial light modulator array according to claim 5, wherein:

said SLM array operates by positionally-selected reflectivity.

21. The enhanced spatial light modulator array according to claim 5, wherein:

said SLM array operates by physically-selected reflectivity.