| 摘要 |
PROBLEM TO BE SOLVED: To improve scanning speed with good stability without increasing the cost of an optical scanner so much. SOLUTION: In the optical scanner having a polygon mirror 2 having a plurality of reflection surfaces and scanning a surface to be scanned by deflecting a light beam 1 made incident on the mirror 2, the light beam is made incident on one reflection surface 21 of the mirror 2 so that the incident positions of the light beam 1 at the time of starting main scanning and at the time of finishing it may be the same on absolute coordinates, and a relay optical system 3 is provided to make the light beam 1 reflected by the reflection surface 21 incident on another reflection surface 22 of the mirror 2 again. The optical system 3 is constituted so that a position where the light beam 1 is made incident on the surface 21 and a position where the light beam 1 is made incident the surface 22 again at the time of starting the main scanning and at the time of finishing it are optically conjugate at least in a main scanning direction. COPYRIGHT: (C)2004,JPO |
