| 摘要 |
PURPOSE:To obtain a good-quality copy from any original, by changing the bias voltage applied to the grid of the secondary charging simultaneous exposure equipment to change the correlative curve between the secondary charging simultaneous exposure light quantity and the photosensitive material surface potential. CONSTITUTION:Primary charging equipment 5, secondary charging simultaneous exposure equipment 7 with grid 6, lamp 8 for exposure of all of the surface, potential sensor 9, and so on are arranged around drum-form photosensitive material 3. The bias voltage applied to the grid of the secondary charging simultaneous exposure equipment is changed to set correlative curves shown by the dotted line and the solid line for line drawing originals or gray originals and area picture originals, for example, high-density originals such as silver salt photographs respectively. The correlative curve shown by the solid line is used for copying of ordinary originals, and the correlative curve shown by the dotted line is used for copying of this gray and white originals, so that gray and white originals and black originals can be reproduced with a distinct variable densities. Thus, a good-quality copy can be obtained from any original. |
