| 摘要 |
PURPOSE:To provide a copying machine capable of preventing the pollution of a transfer roller by the toner of a reference toner image on a photoreceptor and prolonging the life of the transfer roller. CONSTITUTION:The separating means of a transfer roller 5 is controlled so that the transfer roller 5 is separated from a photoreceptor 1 before a reference toner image 6 reaches the facing position of a photoreceptor 1 and the transfer roller 5 and the transfer roller 5 is brought into contact with the photoreceptor 1 after the reference toner image 6 passes through the facing position. The separating means is constituted of an arm member 9 rotatably connected with the transfer roller 5 and supported on a spindle 10, a spring 11, and a solenoid 12. The separating means may be formed with a cam having a prescribed shape so that the transfer roller 5 is slowly brought into contact with the photoreceptor 1. An arm member for moving a P sensor 7 and a shutter for protecting the P sensor 7 are connected for the separating means, the P sensor 7 is moved to the detecting position only when the transfer roller 5 is separated, or the shutter may be moved from the detecting face of the P sensor 7. |
