| 摘要 |
PROBLEM TO BE SOLVED: To solve the following problems regarding an image forming apparatus for superposing color images through the use of a plurality of image carriers, currently, plastic materials are largely used for an optical device for a scanning optical system, but the shape of the optical device is often deviated from the ideal one due to a molding condition and a temperature condition, etc., further, these errors including an attaching error of the optical element with a housing cause curving of a scanning line and positional deviation; thereby, color drift occurs, and image quality is remarkably reduced. SOLUTION: When the scanning line is tilted, the tilt of the scanning line can be corrected by using the oscillation of a return mirror M with one end thereof as an axis, the level of the correctable tilt is varied in accordance with the size of a deflection angle to reflect a light beam. That is, if the deflection angle is small, the tilt may not be sufficiently corrected even by increasing the oscillation amount. An image light beam having the highest brightness of color is assigned for the return mirror so as not to make the insufficient correction conspicuous. COPYRIGHT: (C)2009,JPO&INPIT |
