| 摘要 |
PURPOSE:To prevent a fog phenomenon at background part in a selective transcription mode and simultaneously to eliminate an out-of-focus phenomenon at the periphery of a picture part, by removing selectively the toner of a low charge amount before the selective transcription process. CONSTITUTION:The tone 1 in a hopper 9 is attached evenly to the surface of a drum-shaped toner toll 2, and the electric charge is injected evenly to the toner 1 when the toner passes through a doctor plate 3 to which the bias voltage is applied for electrification. Then the voltage signals corresponding to the picture information are applied to a multi-needle electrode 4 having a contact with a toner layer is charged with the polarity opposite to its original polarity. Then the low charge toner is selectively removed by a sucking device 6 between the electrode 4 and a copy roll 8. Thus only the toner charged with the polarity of one side is recorded selectively on a recording paper 7 and fixed. Thus it is possible to prevent a fog phenomenon at a background part and also to eliminate an out-of-focus phenomenon at the periphery of a picture part. This improve the picture part. This improves the picture quality. |
