| 摘要 |
PROBLEM TO BE SOLVED: To obtain a fine image in consequence of excellent transfer by minimizing the irregularity of resistance in the rotary direction of a transfer roller, performing application of constant current bias on the transfer roller and detection of generating voltage without differential, in the short time less than once round of the transfer roller during the time of passing non-paper, and determining the appropriate bias. SOLUTION: The transfer roller is composed by forming an elastic layer with material such as polar polymer on a core bar on which the transfer bias is applied. The device is allowed to predetermine a transfer voltage for the first sheet by applying the constant current bias on the transfer roller at the time of pre-rotation prior paper passing, and detecting the generating voltage VT01 at the time, by the nest equation, VT1=VT01×(a)+(b), (provided that (a)=1.0, (b)=1.1 kV). On completing the image forming preparation of the image forming device, by letting paper to pass through the transfer nip part, and applying VT1 at the constant voltage on the transfer roller, transferring of the first sheet is performed. Between the paper after completion of transferring, the transfer voltage VT2 applying on the second sheet is predetermined, by applying the constant current bias, and detecting the generation voltage VT02. The device is allowed to repeat the above. |
