Bistable DMD addressing circuit and method
AssigneeTexas Instruments Incorporated
InventorLarry J. Hornbeck
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Abstract
Bidirectional operation of the bistable DMD is preferred over unidirectional operation because it eliminates contrast degradation caused by duty-factor effects and permits lower voltage operation. However, bidirectional addressing requires either two drain lines and two transistors per pixel or one drain line and three transistors per pixel. An addressing scheme for bidirectional operation is disclosed that requires only a single drain line and one transistor per pixel. For megapixel DMDs used for high-definition television applications, this addressing scheme dramatically lowers the transistor count, with expected improvements in chip yield and cost.
Claims18
A spatial light modulation device, said device comprising:
- a multilayered substrate, wherein an upper layer of said substrate contains a defined rotatable beam area;
- a first bias electrode positioned in proximity to said rotatable beam and operative for establishing voltage potential thereon;
- and
- circuitry for selectively establishing an address voltage potential on said beam, said voltage potential operative in conjunction with said voltage potential on said bias electrode for selectively enabling said beam to rotate, wherein said circuitry is in contact with at least one area of said beam.
An array of spatial with modulation devices, said array comprising:
- a multilayered substrate, wherein an upper layer of said substrate contains a plurality of defined controllably rotatable beam areas;
- bias electrodes positioned in proximity to said rotatable beams and operative for establishing different voltage on each said bias electrode;
- and
- circuitry for selectively establishing a voltage potential on said beams, said voltage potential operative in conjunction with said voltage potentials on said bias electrodes for selectively enabling said beams to rotate, wherein said circuitry is in contact with at least one area of each of said beams.
The method of establishing a spatial light modulation device having a defined controllably rotatable beam area, said method comprising the steps of:
- positioning a first bias electrode in proximity to said rotatable beam;
- establishing a voltage potential on said bias electrode;
- selectively establishing an address voltage potential on said beam, said voltage potential operative in conjunction with said established voltage potential on said bias electrode for rotating said beam, wherein said address voltage potential is established by addressing circuitry which is in contact with said beam.
Dependencies are inferred from the claim text.