| 摘要 |
PURPOSE:To reduce speckles by providing a first diffusing plate in the optical path of the light from a pulse laser as a light source and forming the image of the light, which is diffused by this diffusing plate, near a second diffusing plate by a lens and a turning mirror. CONSTITUTION:The light emitted from a pulse laser 1a is scattered by the first diffusing plate 2 and is condensed into approximately parallel rays by a lens 3 and is reflected on a polygonal mirror 4 rotated at a high speed to form the image of the first diffusing plate on the second diffusing plate 6a by a lens 5. An axially symmetrical octagonal mirror is used as the polygonal mirror 4, and an air bearing is used as the bearing of the rotary shaft, and this mirror is rotated at about 1,000rps. Thus, speckles at the rear of the second diffusing plate 6a provided near this image are considerably reduced to form an illuminating device with speckles reduced. |
