| 摘要 |
<p>Disclosed is a thin illumination optical system for use in a projector device. The disclosed illumination optical system in used in a projector device which guides light emitted from a light source to a TIR prism (20), optically modulates light which has been totally reflected on the total reflection surface of said prism (20) by reflecting said light with a DMD (23) having a rectangular surface, and projects said optically modulated light onto a screen. The TIR prism (20) of the illumination optical system is configured such that a projection line, formed by a normal line N normal to said total reflection surface being projected perpendicularly to the surface of the DMD (23), forms an angle other than 90° to a micromirror rotation axis (R) of said DMD (23); such that an emitted light projection line, formed by the principal ray of the light beam (Lout) emitted from the aforementioned total reflection surface being projected perpendicularly to the surface of the DMD (23), forms an angle of 90° with the micromirror rotation axis (R), and also such that an incident light projection line, formed by the principal light beam of a light bundle (Lin) incident to the aforementioned total reflection surface being projected perpendicularly to the surface of the DMD (23), is, all the way to the end point, on the same side as the emitted light projection line of a straight line (Q) extending parallel to the long side of the DMD (23).</p> |
