| 摘要 |
PROBLEM TO BE SOLVED: To maintain an optimum transfer condition and to enhance the printing quality by providing a printer with a current monitor circuit measuring a leakage current flowing because a high voltage for transfer is impressed on the transfer path of a medium, calculating the impedance of the medium by deducting the leakage current from a transfer current supplied immediately after the medium enters a transfer unit and deciding a power source voltage for transfer. SOLUTION: This printer is provided with a current monitor circuit 47 for measuring the leakage current at a paper supply mechanism part including a paper supply roller 46 and the like. The transfer voltage is impressed on the part of a transfer roller 16 from a high voltage power source circuit 18 for transfer and the current flowing in the direction to the transfer unit 45 is measured by the current monitor circuit 44. Only an example that the current monitor circuit 47 is used for the part of the roller 46 is shown here. However, the respective parts of the printer are provided with such a circuit so as to measure the leakage current as precisely as possible. The measured result is inputted to the power source circuit 18 and the real impedance of the medium 17 at the part of the transfer unit 45 is measured by the current obtained by deducting the leakage current. |
