| 摘要 |
PROBLEM TO BE SOLVED: To prevent potential by electrification from being changed even by increasing a transfer current at the power source device of an image forming device where a high voltage power source supplying an electrifying device and a transferring device with high voltage is made common. SOLUTION: A variable high voltage resistance 11 is serially inserted into between the electrifying device 2 and the high voltage power source 10, and a grid voltage controlling means 12 increasing and decreasing supplied voltage to the grid electrode 2a of the electrifying device 2 is provided, and a transfer mode changeover means 17 and a controller 16 are provided. Then, when the changeover means 17 instructs the increase of a transfer current to the controller 16, the controller 16 increases the output of the high voltage power source 10, and decreases grid voltage by using the grid voltage controlling means 12. Or, the resistance value of the variable high voltage resistance 11 is increased, so that the grid voltage is raised. |
