THERMO-MECHANICALLY ACTUATED REFLECTIVE STRUCTURE
One embodiment of an optical modulator includes a substrate, a reflective structure, and at least three thermally actuated supports that movably support said reflective structure on said substrate.
Optical devices, such as optical modulators, may include one or more movable members, such as one or more movable reflective plates, positioned on a substrate. The movable reflective plate may be moved between a first position and a second position such that light impinging thereon will be reflected from the plate in one of two predetermined directions. It may be desirable to move the plate into three or more positions so that light reflected from the plate may be directed to one of a variety of projection systems or light dump structures.
BRIEF DESCRIPTION OF THE DRAWINGS
Each of contact pads 24 may be operatively connected to a temperature modulating device, such as a heater 30, that operates to individually, selectively heat (or cool, as the case may be) each of supports 22 to a desired predetermined temperature. In one embodiment heater 30 is a complimentary metal oxide semiconductor (CMOS) that operates to heat each of supports 22 by applying a voltage across corresponding pad 24. In such an embodiment, heater 30 may be a voltage source. Each of supports 22 may be secured to substrate 18 only at contact pad 24 such that upon heating by heater 30 supports 22 moves, thereby moving plate 20 from an initial first position into a desired, predetermined second position. Each of supports 22 may be individually, selectively moved a unique amount such that plate 20 may be tilted into a number of different tilt positions with respect to the x, y, and z axes.
In another embodiment, support 22 may define a bent nominal orientation wherein subjecting the support to heat may move the support into a flat orientation. In still another embodiment, support 22 may define a first bent nominal orientation wherein subjecting the support to heat may move the support into a second bent orientation. In still other embodiments, support 22 may include more than two layers, such as three or four layers, and may include layers that extend only along a portion of length 34. Accordingly, any multi-layered arrangement of materials having coefficients of thermal expansion different from one another may be utilized in an embodiment of the present invention. Moreover, the arrangement, dimensions and other similar variables of the multilayered support 22 may be varied to suit a particular application.
In the example shown, two of supports 22 have moved upwardly through distance 40 such that first end 42 of plate 20 is moved upwardly with respect to substrate 18 and such that a second end 44 of plate 20 remains proximate with substrate 18. Accordingly, heating two of supports 22 to a substantially similar temperature over a substantially similar time period allows plate 20 to be tilted to a desired angle 46, such as an angle 46 in a range of greater than zero degrees and up to 180 degrees. In the embodiment shown, angle 46 is in the range of one to forty-five degrees. In another embodiment, supports 22 may be cooled such that the coefficient of thermal expansion may result in movement of plate 20 into a desired predetermined position. In such an embodiment, the temperature modulating device may act to cool one or more of supports 22.
Support 22, as shown in
In conclusion, while the present invention has been particularly shown and described with reference to the foregoing embodiments, those skilled in the art will understand that many variations may be made therein without departing from the spirit and scope of the invention as defined in the following claims. This description of the invention should be understood to include the novel and non-obvious combinations of elements described herein, and claims may be presented in this or a later application to any novel and non-obvious combination of these elements. The foregoing embodiments are illustrative, and no single feature or element is essential to all possible combinations that may be claimed in this or a later application. Where the claims recite “a” or “a first” element or the equivalent thereof, such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements.
Claims
1. An optical modulator, comprising:
- a substrate;
- a reflective structure; and
- at least four thermally actuated supports that movably support said reflective structure on said substrate.
2. The modulator according to claim 1 wherein said reflective structure comprises a mirror.
3. The modulator according to claim 1 wherein said at least four thermally actuated supports each comprise a first material having a first coefficient of thermal expansion and a second material having a second coefficient of thermal expansion different from said first coefficient of thermal expansion.
4. The modulator according to claim 3 wherein said first and second materials are each chosen from the group of plastic, metal, semiconductor material, ceramic, and silicon.
5. The modulator according to claim 3 wherein said first material comprises a first layer, and wherein said second material comprises a second layer positioned on and extending along said first layer.
6. (canceled)
7. The modulator according to claim 1 further comprising a temperature modulating structure coupled to each of said at least four thermally actuated supports to individually heat each of said supports to a predetermined temperature.
8. The modulator according to claim 7 wherein said temperature modulating structure comprises a complimentary metal oxide semiconductor.
9. An optical modulator, comprising:
- a substrate;
- a reflective structure; and
- at least three thermally actuated supports that movably support said reflective structure on said substrate wherein said at least three thermally actuated supports each comprise different materials from the other two supports.
10. The modulator according to claim 1 wherein thermally actuating said at least four thermally actuated supports moves said reflective structure, wherein said movement is chosen from at least one of tilting movement and rotational movement.
11. A method of moving a reflective structure of an optical modulator, comprising:
- supporting said reflective structure on a substrate with three supports, each of said three supports including at least two materials have different coefficients of thermal expansion; and
- heating one of said three supports to a predetermined temperature to move said reflective structure into a predetermined position wherein said predetermined temperature is different for each of said three supports.
12. (canceled)
13. A method of moving a reflective structure of an optical modulator, comprising:
- supporting said reflective structure on a substrate with three supports, each of said three supports including at least two materials have different coefficients of thermal expansion; and
- heating one of said three supports to a predetermined temperature to move said reflective structure into a predetermined position wherein said at least two materials of each of said three supports includes material different from the other two supports.
14. The method according to claim 11 wherein said first and second materials are each chosen from the group of plastic, metal, semiconductor material, ceramic, and silicon.
15. The method according to claim 11 wherein said first material comprises a first layer, and wherein said second material comprises a second layer positioned on and extending along said first layer.
16. A method of moving a reflective structure of an optical modulator, comprising:
- supporting said reflective structure on a substrate with three supports, each of said three supports including at least two materials have different coefficients of thermal expansion; and
- heating one of said three supports to a predetermined temperature to move said reflective structure into a predetermined position wherein said optical modulator comprises a plurality of reflective structures positioned on said substrate, each of said plurality of reflective structures supported on said substrate by three supports, and wherein said heating comprises heating one of said three supports of said plurality of reflective structures to a predetermined temperature to move one of said plurality of reflective structures into a corresponding predetermined position.
17. A method of moving a reflective structure of an optical modulator, comprising:
- supporting said reflective structure on a substrate with three supports, each of said three supports including at least two materials have different coefficients of thermal expansion; and
- heating one of said three supports to a predetermined temperature to move said reflective structure into a predetermined position wherein a complimentary metal oxide semiconductor structure is operatively connected to each of said three supports, and wherein said heating comprises applying a voltage to selected one of said complimentary metal oxide semiconductor structure to selectively heat one of said three supports.
18. The method according claim 11 wherein said supports are nominally positioned linearly and move to a bent position when heated.
19. A method of moving a reflective structure of an optical modulator, comprising:
- supporting said reflective structure on a substrate with three supports, each of said three supports including at least two materials have different coefficients of thermal expansion; and
- heating one of said three supports to a predetermined temperature to move said reflective structure into a predetermined position wherein said heating comprises increasing a temperature of said supports by a temperature change in a range of one to four hundred degrees Kelvin.
20. A method of moving a reflective structure of an optical modulator, comprising:
- supporting said reflective structure on a substrate with three supports, each of said three supports including at least two materials have different coefficients of thermal expansion; and
- heating one of said three supports to a predetermined temperature to move said reflective structure into a predetermined position wherein said heating comprises utilizing a 5×7 micrometer tungsten heater.
21. A method of moving a reflective structure of an optical modulator, comprising:
- supporting said reflective structure on a substrate with three supports, each of said three supports including at least two materials have different coefficients of thermal expansion; and
- heating one of said three supports to a predetermined temperature to move said reflective structure into a predetermined position wherein said heating comprises utilizing power in a range of 0.1 to 2.5 microwatts per degree Kelvin temperature raise.
22. A thermally actuated movable micro-mirror, comprising:
- a micro-mirror structure having four corners; and
- four movable bilayer supports operatively connected to a corner of said micro-mirror structure, said movable bilayer supports each including a first layer of material having a first coefficient of thermal expansion and a second layer of material having a second coefficient of thermal expansion different from said first coefficient of thermal expansion.
23. The mirror according to claim 22 wherein said bilayer supports are nominally positioned linearly and bend when heated, wherein an amount of said bend is proportional to a difference between said first and second coefficients of thermal expansion.
24. The mirror according to claim 22 wherein said bilayer supports are nominally positioned linearly and bend when heated, wherein an amount of said bend is proportional to a temperature to which each support is heated.
25. (canceled)
26. The mirror according to claim 22 wherein each of said bilayer supports comprises an elongate member connected at a first end to a substrate and connected at a second end to a corner of said micro-mirror structure.
27. A reflection device, comprising:
- means for reflecting light; and
- three thermally actuated means for supporting said means for reflecting wherein said means for reflecting light comprises an array of micromirrors.
28. The device according to claim 27 wherein each of said thermally actuated means for supporting comprise an elongate member including a first layer and a second layer both extending along a length of said elongate member, said first and second layers defining a coefficient of thermal expansion mismatch therebetween.
29. The device according to claim 28 wherein each of said three elongate members are secured at a first end to said means for reflecting light and secured at a second end to a support.
30. The device according to claim 29 wherein each of said three elongate members are operatively connected to a heater at their second end.
31. A reflection device, comprising:
- means for reflecting light; and
- three thermally actuated means for supporting said means for reflecting, wherein each of said three thermally actuated means for supporting comprise an elongate member including a first layer and a second layer both extending alone a length of said elongate member, said first and second layers defining a coefficient of thermal expansion mismatch therebetween and wherein each of said three elongate members are secured at a first end to said means for reflecting light and secured at a second end to a support and wherein each elongate members are operatively connected to a tungsten resistive pathway at their second end.
32. The device according to claim 30 wherein each of said three elongate members bend along their length with respect to a nominal position when heated.
33. (canceled)
34. A thermally actuated mirror system, comprising:
- a mirror; and
- at least three supports positioned around and movably supporting said mirror, said at least three supports being thermally actuated to position said mirror in a variety of predetermined x, y and z orientations.
35. The mirror according to claim 34 wherein said at least three supports each comprise a multi-material member including a first material that expands by a first expansion amount when heated and a second material that expands by a second expansion amount when heated, said second expansion amount different from said first expansion amount.
36. The mirror according to claim 34 further comprising a fourth support, said four supports equally positioned around a perimeter of said mirror.
37. The mirror according to claim 35 wherein said first material comprises a first layer of said member and said second material comprises a second layer of said member, said first and second layers both extending along a length of said member.
38. The mirror according to claim 34 wherein said mirror is angularly positioned with respect to an initial position at a first angle in a range of one to forty-five degrees with respect to an x axis, at a second angle in a range of one to forty-five degrees with respect to a y axis, and at a third angle in a range of one to forty-five degrees with respect to a z axis.
39. The mirror according to claim 34 wherein said at least three supports are positioned within a perimeter of said mirror, and wherein said mirror system includes a plurality of mirrors positioned substantially directly adjacent one another.
Type: Application
Filed: Jan 27, 2005
Publication Date: Jul 27, 2006
Inventors: Alexander Govyadinov (Corvallis, OR), Curt Van Lydegraf (Boise, ID)
Application Number: 11/045,710
International Classification: G02F 1/01 (20060101);