IMAGE FORMING APPARATUS

摘要

An image forming apparatus capable of suppressing deterioration of a charger although an amount of use of the charger is actually small is provided. For that purpose, the image forming apparatus executes simple control of discharge current control in which at least one charging bias smaller in number than number of kinds of test biases in full control of the discharge current control is applied to the charger after a power source is turned on and before an image formation start signal is inputted, and on the basis of a current detected by the detector when the charging bias is applied, selects one from a plurality of modes including a first mode in which a charging bias is set by executing the full control of the discharge current control and including a second member in which the charging bias determined by full control of discharge current control without executing the full control of the discharge current control.

主权项

1. An image forming apparatus comprising:
a photosensitive member; a charger for electrically charging said photosensitive member when an image is formed on said photosensitive member; a bias applying device for applying, to said charger, a charging bias including a DC voltage and an AC voltage which are superimposed; a detector for detecting a current passing through said charger; a regulator for regulating a peak-to-peak voltage of the charging bias on the basis of a current detected by said detector when a plurality of test biases different in peak-to-peak voltage from each other are applied in a test mode in which the plurality of test biases are applied to said charger; and a selector for selecting one from a plurality of modes including a first mode in which the charging bias is set by executing the test mode and including a second mode in which the charging bias regulated though a last test mode without executing the test mode is set, on the basis of the current detected by said detector when at least one check bias smaller in number than number of kinds of the test biases is applied in a check mode in which said check bias is applied after a power source of said image forming apparatus is turned on and before an image formation start signal is inputted.