| 摘要 |
PURPOSE:To prevent the function of the corona discharge for transcribing in reverse charge polarity to a non-image part and to secure the even potential on the surface of a photoreceptor, by increasing or decreasing the effective discharge region of a corona discharging means provided at a transcription part in accordance with the width of a carrier sheet to be transcribed. CONSTITUTION:A masking plate 6 is put at the edge of a discharge aperture part of a transcription charger 4 and slides within a guide groove 5 so as to cover a part of the aperture part. This plate 6 is made of a dielectric material like the synthetic resin, etc. to mask over the both sides of a paper feed mechanism based on a center part and to cover a single side of the said mechanism based on the end surface respectively. Thus the effective discharge region is reduced for the charger 4. Furthermore an end of the plate 6 is connected to a solenoid 7 via a ball crank 8 and driven by the solenoid 7 which works by the paper size signal obtained through control of the designation of the paper size, the designation of magnification or the detection of the paper size. Thus the aperture part is opened and closed. |
