| 摘要 |
PURPOSE:To obtain images of high quality by using a standard reflecting plate and copying with the reduction of the optical sensor output to detect an accurate original density. CONSTITUTION:When a power source is turned on, a motor 31 is driven to move a light source 40 and an optical sensor 42 under a standard reflecting plate 43, and the quantity of the reflected light from the standard reflecting plate 43 is detected and is defined as a reference light quantity. When a copy start button is depressed, motors 21 and 31 are driven to move light shielding films 3 and 4, and motors 21 and 31 are stopped to detect the quantity of the reflected light from an original when optical sensors 41 and 42 detect the original. The reference light quantity is compared with this quantity of the reflected light from the original to discriminate the original density, and an applied voltage of an exposure lamp 6 is determined, and its signal is outputted to an exposure lamp voltage control circuit 48 to control the quantity of the emitted light of the exposure lamp, and the normal copying work is started. |
