Microelectrical mechanical structure (MEMS) optical modulator and optical display system

• US 6,967,761 B2
• Filed: 06/21/2004
• Issued: 11/22/2005
• Est. Priority Date: 10/31/2000
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Sinclair, Michael J., Starkweather, Gary K.
• Primary Examiner(s): THOMPSON, TIMOTHY J
• Application Number:
  US10/873,070
• Publication Number:
  US 20040233498A1
• Time in Patent Office: 519 Days
• Field of Search: 359/291, 359/290, 359/292, 359/223, 359/224, 359/230, 359/288, 359/302, 359/621, 359/622, 359/623, 359/295
• US Class Current: 359/291
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• CPC Class Codes: G02B 6/353 the optical element being a shutter, baffle, beam dump or opaque element absorbers on light guide termination G02B6/243
• CPC Class Codes: G02B 6/3554 3D constellations, i.e. with switching elements and switched beams located in a volume
• CPC Class Codes: G02B 6/356 in an optical cross-connect device, e.g. routing and switching aspects of interconnecting different paths propagating different wavelengths to (re)configure the various input and output links switching polarized beams G02B6/3594; power equalizers G02B6/356 and G02B6/3594; path selecting means H04Q11/0001
• CPC Class Codes: G02B 6/3576 Temperature or heat actuation thermal forces controlling reflecting elements in general G02B26/0866; thermo-optic devices G02F1/0147
• CPC Class Codes: G02B 6/3584 constructional details of an associated actuator having a MEMS construction, i.e. constructed using semiconductor technology such as etching MEMS per se B81B, B81C
• CPC Class Codes: G02B 6/3594 Characterised by additional functional means, e.g. means for variably attenuating or branching or means for switching differently polarized beams
• CPC Class Codes: H04N 5/7408 Direct viewing projectors, e.g. an image displayed on a video CRT or LCD display being projected on a screen
• CPC Class Codes: H04N 5/7416 involving the use of a spatial light modulator, e.g. a light valve, controlled by a video signal

Abstract

A microelectrical mechanical out-of-plane thermal buckle-beam actuator is capable of providing transverse-plane movement of shutters. The actuator includes a pair of structural anchors secured to a substrate and one or more thermal buckle-beams secured at respective base ends to the anchors. Each buckle-beam extends substantially parallel to and spaced-apart from the substrate and is releasable from the substrate at points other than at the anchors. The thermal buckle-beam actuators are suitable for use in a microelectrical mechanical optical display system.

Claims

1. A microelectrical mechanical optical display system, comprising:

an illumination source that provides illumination light;

a collimating lens that receives the illumination light and forms from it collimated illumination light;

a converging microlens array having an array of plural lenslets that converge the collimated illumination light;

a microelectrical mechanical optical modulator including a planar substrate through which plural pixel apertures extend and plural microelectrical mechanical out-of-plane thermal buckle-beam actuators that support and selectively position plural microelectrical mechanical shutters over the apertures, the microelectrical mechanical optical modulator being positioned such that the pixel apertures receive the illumination light from the converging microlens array, the illumination light passing the microelectrical mechanical optical modulator selectively according to the selective positioning of the shutters;

a display screen that receives the illumination light passing the microelectrical mechanical optical modulator; and

a projection microlens array positioned between the microelectrical mechanical optical modulator and the display screen and having an array of plural lenslets that project the illumination light to the display screen.

2. The display system of claim 1 in which the microelectrical mechanical out-of-plane thermal buckle-beam actuators of the microelectrical mechanical optical modulator are thermal microelectrical mechanical actuators.

3. The display system of claim 1 in which the illumination source includes only one light source.

4. The display system of claim 1 in which the illumination source includes plural light sources of different colors.

5. The display system of claim 4 further comprising a field sequential controller that operates the plural light sources alternately and controlling the shutters in coordination with the light sources in a field sequential manner.

6. The display system of claim 1 in which the display screen is a transmissive display screen.

7. The display system of claim 1 further comprising a housing that contains the display system to form a display module that can fit together with or engage other such display modules.

8. The display system of claim 1 in which the illumination source is monochrome.

9. The display system of claim 1 in which the illumination source is polychromatic.

10. A microelectrical mechanical optical display system, comprising:

an illumination source that provides illumination light;

a collimating lens that receives the illumination light and forms from it collimated illumination light;

a converging microlens array having an array of plural lenslets that converge the collimated illumination light;

a microelectrical mechanical optical modulator including a planar substrate through which plural pixel apertures extend and plural microelectrical mechanical out-of-plane thermal buckle-beam actuators that support and selectively position plural microelectrical mechanical shutters over the apertures, the microelectrical mechanical optical modulator being positioned such that the pixel apertures receive the illumination light from the converging microlens array, the illumination light passing the microelectrical mechanical optical modulator selectively according to the selective positioning of the shutters; and

a display screen that receives the illumination light passing the microelectrical mechanical optical modulator;

wherein the microelectrical mechanical out-of-plane thermal buckle-beam actuators of the microelectrical mechanical optical modulator are thermal microelectrical mechanical actuators.

11. The display system of claim 10 in which the illumination source includes only one light source.

12. The display system of claim 10 in which the illumination source includes plural light sources of different colors.

13. The display system of claim 12 further comprising a field sequential controller that operates the plural light sources alternately and controlling the shutters in coordination with the light sources in a field sequential manner.

14. The display system of claim 12 in which the display screen is a transmissive display screen.

15. The display system of claim 10 further comprising a housing that contains the display system to form a display module that can fit together with or engage other such display modules.

16. The display system of claim 10 in which the illumination source is monochrome.

17. The display system of claim 10 in which the illumination source is polychromatic.