APPARATUS FOR CONTROLLING LIGHT QUANTITY OF SEMICONDUCTOR LASER, IMAGE FORMING APPARATUS, AND METHOD OF CONTROLLING LIGHT QUANTITY OF THE SEMICONDUCTOR LASER

摘要

PROBLEM TO BE SOLVED: To provide a light quantity control apparatus for a semiconductor laser, an image forming apparatus and a method of controlling a light quantity of the semiconductor laser wherein an emission level of the semiconductor laser can be maintained at an adequate level even when a sudden change in a printing rate occurs. SOLUTION: The light quantity control apparatus for the semiconductor laser 1 controls a bias current by adding an additional bias current IBA to a bias current IBF in a driving current of the semiconductor laser 1 corresponding to a printing rate in a predetermined time period by a printing rate detecting section 11. A correction current IBR corresponding to a difference of the printing rate between the targeting predetermined time period and a time period before the targeting time period by one cycle is added to or subtracted from the bias current to which the additional bias current is added during the printing in the targeting time period.