Patent ID: 8125503

Claim:
An image forming apparatus comprising: a semiconductor laser that emits a laser beam, light power of the laser beam being controllable by a current applied to the semiconductor laser; a scanner unit that exposes a photosensitive element by scanning the photosensitive element using the laser beam; a light power detection unit that detects light power of the laser beam; a current control unit that controls the current applied to the semiconductor laser according to the light power of the laser beam; a home position detection unit that detects whether the laser beam is positioned at a scan home position; and a continuous illumination unit that computes a length of time during which illumination of the semiconductor laser is used to form an image, based on a timing at which the home position detection unit detects the laser beam; commences continuous illumination of the semiconductor laser after an elapse of the length of time which is computed; and terminates continuous illumination of the laser after an elapse of an amount of time taken for control to be performed by the current control unit.