| 摘要 |
PURPOSE:To increase the image density of image, by feeding the tip of a print wire in a toner layer on a donor in accordance with a print signal and selectively charging toner with friction charging. CONSTITUTION:When the surface of a donor roller 1 fitted with a toner 2 goes out of a hopper 7, electric charges are injected with a doctor blade electrode 3 and the toner layer can uniformly be charged. Based on a print signal, a print wire 4 is selectively fed from a print head 9 to the charged toner layer to form a charge pattern of opposite polarity according to the print signal in the toner layer precharged with the blade 3. The charge pattern is copied on a copying paper 5 fed between the roller 1 and the copying roller 6 to form a visual image. Thus, the discharge of a charging toner can be avoided in case of using multistylus electrodes and copying can be made while holding the charged potential sufficiently, allowing to increase the image density of picture. |
