| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a platemaking apparatus for a printing plate, the apparatus which varies a beam diameter at an extremely low cost. <P>SOLUTION: When a movable mirror 81 is placed at a deviation position, a laser beam exiting from a laser light source 14 toward an objective lens 46 and modulated by an AOM (acoustooptic modulator) 41, is reflected on a reflecting surface 81a of the movable mirror 81 to be deflected. After the laser beam is reflected on reflecting surfaces 82a, 82b of a fixed mirror 82, the beam is reflected on the reflecting surface 81b of the movable mirror 81 and again returns in the optical path from the laser light source 14 to the objective lens 46. On the other hand, when the movable mirror is placed at a retreating position, the laser beam exiting from the laser light source 14 toward the objective lens 46 and modulated by the AOM 41 directly, enters the objective lens 46. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
