Image formation apparatus provided with photoconductor and charging device

1. An image formation apparatus comprising:

a photoconductor;

a charging section that applies a bias voltage having an AC voltage superposed on a DC voltage to the photoconductor so as to charge the photoconductor;

a controller that controls at least one of the AC voltage and an AC current in response to a fluctuation amount of a DC current-flowing between the photoconductor and the charging section when an AC voltage is applied; and

a detector that detects the DC current.

2. The image formation apparatus according to claim 1 , wherein the controller controls the at least one of the AC voltage and the AC current so that the fluctuation amount of the DC current is within a range containing an inflection point when the fluctuation amount of the DC current changes in response to change of the at least one of the AC voltage and the AC current.

3. The image formation apparatus according to claim 1 , further comprising an environment detector that detects an environment, wherein the controller changes an initial value of control in response to a detection result of the environment detector.

4. The image formation apparatus according to claim 1 , wherein the photoconductor has an abrasion amount of 20 nm or less for 1,000 revolutions thereof.

5. The image formation apparatus according to claim 1 , wherein the photoconductor comprises a charge transport layer having a thickness of 25 μm or less.

6. The image formation apparatus according to claim 3 , wherein the environment detector detects at least one of a temperature value and a humidity value as the environment.