JPH05289525

PURPOSE:To prevent first copying time from being made unnecessarily long by detecting a period of time from the drive of a motor in a developing tank on the depression of a print switch to the start of the formation of a latent image by means of a scanning illuminator and a scanning mirror and the temperature of developer, and properly controlling them. CONSTITUTION:A temperature sensor 30 is provided in the developing tank 20. The temperature of the developer and a period of time from the time when the drive of a pump in the developing tank 20 is started to the time when a sufficient amount of developer which does not cause missing of an image builds up between the surface of a first developing roller 91 and the surface of a photosensitive body 8 are determined by an experiment. Based on those and the output of the temperature sensor 30, an optical scanner motor for moving the scanning illuminator 2, etc., is controlled.