| 摘要 |
PURPOSE:To prevent a potential sensor from receiving the effect of the potential of a transfer belt by turning off the transfer charger of a recorder on the upstream side of the carrying direction of the transfer belt at the timing that surface potential is detected. CONSTITUTION:A photosensitive body on the upstream side is regarded as 14Bk and an object whose potential is detected is regarded as a photosensitive body 14C. T1 shows a time that the body 14C is moved to the potential sensor SC from the transfer position of the transfer charger 17C, T2 shows a potential measuring allowable time and T3 shows a time that the transfer belt 21 is moved as much as an interval that an image is formed. Then, the transfer charger on the upstream side is turned off at the timing that the surface potential is detected. As for the part where the potential is measured, the actual potential at the time of forming the image is measured as well as conditions at the time of forming the image. Since the transfer charger on the upstream side of the carrying direction of the transfer belt is turned off when the surface potential is detected in such a way, the potential sensor detecting the surface potential does not receive the effect of the potential of the transfer belt and the potential is precisely detected. |
