| 摘要 |
PURPOSE:To eliminate ground stains, enhance image density and increase recording speed by holding a fixed spacing between the developer carried on a counter electrode and a recording sheet and applying ultrasonic vibrations to the counter electrode. CONSTITUTION:The spacing between a recording electrode 5 and a counter electrode 6 is maintained at a value nearly equal to the paper thickness of a recording sheet S and the developer 7 carried to the counter electrode maintains a fixed spacing without making contact with the sheet S. A vibration energizing means is taken to the counter electrode 6 and is bonded with an ultrasonic wave vibrator 10. Excitation current is intermittently supplied to the vibrator 10 from an ultrasonic wave generating source 12 in synchronization with the recording operation. The ultrasonic wave vibrations cause the surfaces of the developer 7 to wave and the wave tops are torn off by the image signal and are directly deposited on the sheet S side, whereby toner images are formed. Since the developer does not contact the sheet, there are no ground stains and the recording speed may be increased. |
