| 摘要 |
PURPOSE:To control print density by varying the amount of toner sticking on an electrostatic latent image and to obtain invariably excellent prints by varying the rotating speed of a magnet motor and then varying the rotating speed of a magnet roller which supplies toner to the photosensitive surface of a photosensitive body. CONSTITUTION:A DC motor 61 which drives the magnet roller for supplying toner to a hotosensitive surface is driven at a constant rotating speed corresponding to a voltage inputted to the inverted input terminal of a voltage comparator 47, i.e. a reference voltage determined by a resistance 41 and a variable resistance 43. Then, the rotting speed is adjusted finely by varying the variable resistance 43 as long as the output state of an I/O port 25 is constant. Therefore, when the output terminal P1 of the I/O port 25 is at a level H, the roller 64 is rotated by the rotation of the rotation of the motor 61 so that toner is supplied by an amount corresponding to normal density. When an output terminal P2 of the I/O port 25 is at the level H, on the other hand, the roller is rotated by the motor 61 so that a thick density state is entered. Thus, the roller 64 is controlled by controlling the rotating speed of the motor 61 to adjust the print density finely among a thick, a normal, and a thin value, thereby obtaining images of good quality. |
