| 摘要 |
<p>PROBLEM TO BE SOLVED: To detect a defective micromirror and to measure the reflectivity, etc., by monitoring operation state of each micromirror. SOLUTION: In a digital micromirror device 10, micromirrors are arranged in matrix. Each micromirror, according to mirror drive data, displaces itself into valid reflection state or invalid reflection state. When in valid reflection state, reflected spot light comes into an image forming light channel 32, and a photographic paper 34 is exposed to it. When in invalid reflection state, reflected spot light comes into a removal light path 27. The removal light path 27 is provided with a photodetective element 29 which measures spot light. By setting each micromirror to invalid reflection state one by one, and measuring the reflection light with the photodetecting element 29, presence of defect and reflectivity of the micromirror are examined. By setting all micromirrors to invalid reflection state at the same time, and examining the output of the photodetecting element, correctness of light quantity of the light source is examined.</p> |
