| 摘要 |
PROBLEM TO BE SOLVED: To grasp the states of toner and recording paper and to attain excellent transfer by controlling a transfer condition according to the secular change of two environmental data on environment near a developing means and near a paper supply means. SOLUTION: The transfer condition is controlled cosidering a difference between the environment near paper supply cassettes 31 to 33 and the environment near developing devices 27 to 30 and the difference of the secular change of the characteristic of the recording paper and the toner. A CPU 14 controls output from a transfer charger HV power source 212 and a pretransfer charger HV power source 131 in accordance with the values of absolute humidity detected by an environment sensor 15 detecting the absolute humidity near the developing devices 27 to 30 and the absolute humidity detected by an environment sensor 18 detecting the absolute humidity near the cassettes 31 to 33. A current is always supplied to the sensors 15 and 18 separately from a main power source supplying power to the driving part, such as a motor, of a copying machine main body. Thus, the image with stable density is formed on the recording paper regardless of the states of the recording paper and the toner. |
