| 摘要 |
<P>PROBLEM TO BE SOLVED: To correct optical path displacement accurately even if optical path displacement is caused by a temperature change of a printing head. <P>SOLUTION: The image forming apparatus has a printing head 10Y incorporating an optical element group provided with at least a first scanning lens 102Y and a second scanning lens 104Y on an optical path. In the second scanning lens 104Y or an optical element disposed downstream of this, its both ends in a normal main scanning direction where a light beam is to be scanned as a polygon mirror 101 is rotated are supported by holders 126Y and 125Y, and temperature altering means for independently altering the temperatures of the support members of the holders 126Y and 125Y is provided. The print head 10Y is disposed in a further downstream of the optical path than the optical element group, and has optical sensors 106Y and 107Y for detecting an angle at which the scanning direction of an actual beam is inclined to the normal main scanning direction. An main body of the image forming apparatus has temperature control means for controlling the temperatures of holders 126Y and 125Y to decrease the inclination angle. <P>COPYRIGHT: (C)2012,JPO&INPIT |
