| 摘要 |
PURPOSE:To appropriately correct the voltage of an exposure lamp and also to eliminate a drastic charge in image density before and after the voltage of the exposure lamp is corrected by reading the reflected light quantity from a reference pattern on a defocal position of an exposure optical system. CONSTITUTION:A reading means constituted of a sensor 37 for reading the reflected light quantity from a white pattern is positioned on the defocal position of a lens 20 among the exposure optical systems 17 to 20. When a scanner is placed on a home position and the white pattern is irradiated with the light of the lighted exposure lamp 16, the reflected light from the white pattern is received by the sensor 37 through the mirrors 17 and 18, and then, the light quantity is read by the sensor 37. Input signals from a control system and the sensor 37, etc., are fetched into a main control system, then, the command is given to an AC control system, and also, a high voltage system, a scanner motor and a developing motor for driving a developing device, etc., are controlled by the main control system, Besides, the main control system is also used as a correcting means for correcting the voltage of the exposure lamp 16 based on the output signal from the sensor 37, and the voltage of the exposure lamp 16 is increased by 1V if a correction flag is set after an image forming operation is started. |
