| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which secures a positional accuracy against the revolving polyhedron of a returning mirror in a usual-using environment without being affected by an irreversible deformation in the high- or low temperature environment of an optical housing wherein different species of components with different thermal expansion coefficients are mounted. <P>SOLUTION: The image forming apparatus is equipped: with an optical housing 12 for supporting the returning mirror 18 for reflecting a laser beam which is radiated inside from a laser beam emitter 14; and a mounting plate 13 composed of a different material having a thermal expansion coefficient different from that of the optical housing 12 and supporting the revolving polyhedron 19 for receiving the laser beam reflected by the returning mirror 18 while being fastened to the optical housing 12 at plural positions through fastening means 27. All the plural fastening means 27 are separated from the straight line for connecting the laser beam emitter 14 to the returning mirror 18 in the optical housing 12. <P>COPYRIGHT: (C)2008,JPO&INPIT |
