| 摘要 |
PURPOSE:To image forming condition is always decided. CONSTITUTION:A photodiode 2 is used to decide the image forming condition by detecting image density. The detection signal of the photodiode 2 is amplified by gain in accordance with the variable resistance value of an electronic volume 5 by a non-reverse amplifier 4, and fetched in a microcomputer 7 through an A/D converter 6. The microcomputer 7 automatically adjusts the output level of the photodiode 2 by controlling the resistance value of the electronic volume 5 so that the input voltage value may be within a specified range. |
