Apparatus for and method of forming images with oscillation mirror

An image forming apparatus which generates a video signal corresponding to an image forming command based on a video clock signal, modulates a light beam according to the video signal, and scans the modulated light beam along a main scanning direction by means of an oscillation mirror which resonates based on a drive signal, so as to form a latent image in an effective image region of a latent image carrier, the apparatus comprising:

• a mirror driver which drives the oscillation mirror;
• a mirror drive controlling section which controls oscillation operation of the oscillation mirror by applying a drive signal, which is synchronized with the video clock signal, to the mirror driver;
• a detector which detects the light beam, which is scanned along the main scanning direction by means of the oscillation mirror in the region away from an effective scan region which corresponds to the effective image region, and outputs a detection signal;
• a write timing adjuster which adjusts a position at which the latent image is written over the latent image carrier by controlling an output timing of the video signal based on the detection signal which is output from the detector;
• a resonant frequency adjuster which adjust a resonant frequency of the oscillation mirror;
• and
• a frequency controlling section which controls the resonant frequency adjuster based on the detection signal which is output from the detector, thereby making the resonant frequency of the oscillation mirror almost coincide with a frequency of the drive signal, while driving the oscillation mirror with the drive signal.