| 摘要 |
PURPOSE:To realize exposure after the temperature of the tube wall of a halogen lamp is set within a proper range by preliminarily turning on a light source at an exposure time, controlling the preliminary turning-on time according to the change of the exposure time and fixing the total turning-on time of the light source every time that a unit image is formed. CONSTITUTION:In the case that the forming magnification of the image is 100%, for example, the halogen lamp is preliminarily turned on (PL) when a scanner is moved to a waiting position W. Then, the halogen lamp is turned off (LO) in order to prevent one point from being concentratedly irradiated at the waiting time until the exposure is started. When a lens part and a movable mirror part arrive at a prescribed position according to an image forming condition and an exposure start feasible state is attained, the halogen lamp is turned on for the exposure (ML). Besides, even after the scanner is moved to a home position HP from the waiting position W and the exposure is finished, the halogen lamp is turned on and held (AL) at the home position HP in a prescribed time and the temperature of the tube wall is maintained. The total turning-on time of the halogen lamp is set by considering a halogen cycle. |
