Display methods and apparatus
The invention relates to light modulators for use in display apparatus. In particular, the invention relates to methods for supporting and support structures for light modulators to reduce unwanted motion.
1. A display apparatus, comprising:
a modulator for selectively interacting with light in an optical path to form an image on the display apparatus;
a controllable first electrostatic actuator providing a first mechanical support for the modulator, said first mechanical support providing a supportive connection from a first location on the modulator to a surface over which the modulator is supported; and
a second mechanical support providing a supportive connection from a second location on the modulator to the surface,
wherein the first electrostatic actuator drives the modulator in a plane substantially parallel to the surface.
2. The display apparatus of claim 1 , wherein the modulator comprises a shutter.
3. The display apparatus of claim 2 , wherein the shutter comprises a plurality of shutter apertures for allowing light to pass through the shutter.
4. The display apparatus of claim 2 , wherein the surface defines an aperture.
5. The display apparatus of claim of claim 1 , wherein the first and second mechanical supports are configured to reduce movement of the modulator out of the plane.
6. The display apparatus of claim of claim 1 , wherein the first electrostatic actuator is connected to the surface in at least two locations to reduce rotational movement of the modulator.
7. The display apparatus of claim of claim 1 , wherein the first electrostatic actuator is sufficiently stiff to reduce movement of the modulator out of the plane.
8. The display apparatus of claim of claim 1 , wherein the connection between the first electrostatic actuator and the modulator is sufficiently thick to reduce movement of the modulator out of the plane.
9. The display apparatus of claim 1 , wherein the first electrostatic actuator is coupled to the modulator at a first side of the modulator, and the second mechanical support is coupled to the modulator at a second side of the modulator.
10. The display apparatus of claim 9 , wherein the first side is substantially opposite the second side.
11. The display apparatus of claim 9 , wherein the first electrostatic actuator is coupled to about the middle of the first side and the second mechanical support is coupled to about the middle of the second side.
12. The display apparatus of claim 1 , wherein the modulator comprises a color filter.
13. The display apparatus of claim 1 , wherein the modulator comprises three color filters.
14. The display apparatus of claim 1 , wherein the first electrostatic actuator is controlled by a passive matrix array.
15. The display apparatus of claim 1 , wherein the first electrostatic actuator is controlled by an active matrix array.
16. The display apparatus of claim 1 , wherein at least one of the first electrostatic actuator and the second mechanical support is mechanically bi-stable.
17. The display apparatus of claim 1 , wherein the first electrostatic actuator and the second mechanical support are between about 0.5 μm and about 5 μm wide.
18. The display apparatus of claim 1 , wherein the first electrostatic actuator comprises a first compliant electrode.
19. The display apparatus of claim 18 , wherein the first electrostatic actuator compnses a second compliant electrode proximate to the first compliant electrode for attracting the first compliant electrode, thereby driving the modulator.
20. The display apparatus of claim 19 , wherein responsive to the first and second compliant electrodes being drawn together, the modulator is moved from a first position to a second position.
21. The display apparatus of claim 18 , wherein the first electrostatic actuator comprises a spring connecting the first compliant electrode to one of the modulator and an anchor connected to the surface.
22. The display apparatus of claim 18 , wherein the first compliant electrode has a first stiffness at a first position along the length of the first compliant member and a greater stiffness at a second position along the length of the first compliant member.
23. The display apparatus of claim 1 , comprising a working fluid having a dielectric constant of at least about 1.5 disposed between the modulator and the surface.
24. The display apparatus of claim 1 , wherein the first electrostatic actuator and a second actuator, the second actuator including the second mechanical support, drive the modulator into at least two mechanically stable positions.
25. The display apparatus of claim 1 , wherein the first electrostatic actuator and a second actuator, the second actuator including the second mechanical support, drive the modulator into at least three mechanically stable positions.