| 摘要 |
In accordance with the present invention, an array of individually addressable micromachined light reflecting ribbons provide a high speed light valve action by employing a method in accordance with which the ribbons flex about their longer axis under the action of an applied electrostatic field. The ribbons are mounted on pedestals such that the resulting micromechanical structures are substantially symmetrical with respect to a plane along their long axis through the centers of the pedestals and normal to the substrate. This micromechanical arrangement ensures a structure with a high natural frequency, thereby allowing high light valve switching speeds. The particular mode of deformation also ensures a robust structure. The method may be applied in either "bright field" or "dark field" (Schlieren) mode. The particular combination of materials employed allows the method to be used in higher incident power applications such as those encountered in the printing industry. The invention uses the fabrication methods developed for grating light valves to build a deformable mirror light valve combining the fabrication and speed advantages of the former with the simplicity of the latter. Since the ribbons flex about their long axes, the amplitude of tip deflection required to produce a given angular light deflection is much smaller than that required by prior art cantilever devices, which flex about their short axes. |
