Patent ID: 7162173

Claim:
An image forming apparatus comprising: a rotatable latent image bearing member for bearing a latent image; charging means contacting with said latent image bearing member and being provided with a voltage applied thereto for charging said latent image bearing member; cleaning means contacting with said latent image bearing member and being adapted to clean said latent image bearing member; and alternate current detecting means capable, when a first AC voltage is applied to said charging means, of detecting an alternate current flowing between said charging means and said latent image bearing member, wherein a peak-to-peak voltage of a charging AC voltage, for charging an area constituting an image forming area on said latent image bearing member, applied to said charging means is selected based on an alternate current detected by said alternate current detecting means, and wherein when a print signal is supplied to said image forming apparatus, the first AC voltage, a second AC voltage and the charging AC voltage are applied to said charging means in order, the second AC voltage having a peak-to-peak voltage higher than that of the first voltage.