Patent ID: 8804149

Claim:
An image forming apparatus including a plurality of optical scanning devices arranged in correspondence with a plurality of photoconductors, configured to scan the corresponding photoconductors with laser light, comprising: an optical scanning device including a light source for emitting laser light, a rotational polygon mirror for reflecting the laser light output from the light source to scan the photoconductor, a motor for rotating the rotational polygon mirror, and a temperature detector for detecting temperature of the optical scanning device; a mode receiver for receiving selection of a single-color image forming mode for forming an image using only one of the plurality of optical scanning devices; a temperature condition judger for judging whether or not a largest temperature difference out of temperature differences between temperature detected by the temperature detector of the one optical scanning device used in the received single-color image forming mode and temperatures detected by the temperature detectors of unused other optical scanning devices satisfies a temperature condition of being larger than a predetermined first temperature difference; and a temperature adjuster for performing an image forming operation in the single-color image forming mode and executing a total motor driving process to drive the motors of the other optical scanning devices at a predetermined first rotation speed if the temperature condition is judged to be satisfied by the temperature condition judger and executing a speed switching process to drive the motors of the other optical scanning devices at a second rotation speed slower than the first rotation speed if the image forming operation in the single-color image forming mode is finished during the execution of the total motor driving process when the selection of the single-color image forming mode is received by the mode receiver.