System and apparatus for repairing micromirrors in spatial light modulators

• US 7,751,114 B2
• Filed: 07/06/2007
• Issued: 07/06/2010
• Est. Priority Date: 02/28/2005
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Richards, Peter, Combes, Michel, Dunphy, James, Patel, Satyadev
• Primary Examiner(s): Mack; Ricky L
• Assistant Examiner(s): Thomas; Brandi N
• Application Number:
  US11/774,533
• Publication Number:
  US 20070258129A1
• Time in Patent Office: 1,096 Days
• Field of Search: 359/256, 359/290, 359/291, 359/292, 359/295, 359/298, 359/237
• US Class Current: 359/292
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

Disclosed herein are a system and apparatus for operating a device that comprises an array of micromirrors. The system and apparatus are usable for repairing stuck micromirrors of the micromirror array during the operation. The reparation applies, at the ON state, two consecutive refresh voltages to the mirror plates of the micromirrors in the array with the pulses being separated in time longer than the characteristic oscillation time of the micromirrors. The reparation can be applied independently to the micromirrors. Alternatively, the reparation can be incorporated with a bias inversion process.

Claims

1. A projection system comprising:

a light source producing illumination light;

a spatial light modulator for modulating the illumination light, the spatial light modulator comprising an array of micromirrors, each micromirror comprising a deflectable mirror plate and an addressing electrode;

a controller in connection with the spatial light modulator, the controller comprising

first means for switching the micromirrors between ON and OFF states,

second means for applying a number of refresh voltage pulses to the mirror plates so as to repair a stuck micromirror, and

wherein a ratio of a number of the switching the micromirrors between the ON and OFF states to the number of refresh voltage pulses is greater than 1.

2. A projection system comprising:

a light source providing illumination light;

a spatial light modulator for modulating the illumination light, the spatial light modulator comprising an array of micromirrors, each micromirror comprising a deflectable mirror plate and an addressing electrode;

a controller in communication with the micromirrors comprising

first means for switching the micromirrors between ON and OFF states with a first bias voltage on the mirror plates and a set of voltages on the addressing electrodes, and

second means for applying first and second refresh voltage pulses to the micromirrors, wherein the first and second refresh voltage pulses are spaced in time longer than an intrinsic oscillation time of the micromirrors.