Conductive member evaluator and conductive member evaluation method

A conductive member evaluator, comprising:

• a cylindrical or spherical first electrode which has contact with an outer circumferential face of a roller-like conductive member rotating about a shaft center, and configured to rotate in a direction opposite the conductive member;
• a second electrode which is connected to the shaft center of the conductive member;
• a voltage applier configured to apply evaluation voltage including at least an AC component between the first electrode and the second electrode;
• a current value measuring device configured to measure a current value flowing between the first electrode and the second electrode when the evaluation voltage is applied by the voltage applier;
• an extreme value obtaining device configured to obtain at least one value amongst a maximum value and a minimum value in one cycle of the AC component included in the current value from the current value measured by the current value measuring device;
• and
• an evaluation device configured to evaluate the conductive member based on said at least one value obtained by the extreme value obtaining device,
• wherein the evaluation device is configured to calculate a variation of the obtained value, per unit time in a predetermined evaluation period, obtained by the extreme value obtaining device, and evaluate the conductive member based on a result in which the variation is compared to a previously defined standard variation value.

A conductive member evaluation method, comprising:

• a voltage applying step of applying evaluation voltage including at least an AC component between a cylindrical or spherical first electrode which has contact with an outer circumferential face of a roller-like conductive member rotating about a shaft center, and configured to rotate in a direction opposite the conductive member and a second electrode which is connected to the shaft center of the conductive member;
• a current value measuring step of measuring a current value flowing between the first electrode and the second electrode when the evaluation voltage is applied by the voltage applying step;
• an extreme value obtaining step of obtaining at least one value amongst a maximum value and a minimum value in one cycle of the AC component included in the current value from the current value measured by the current value measuring step;
• and
• an evaluation step of evaluating the conductive member based on said at least one value obtained by the extreme value obtaining step,
• wherein the evaluation step calculates a variation of the obtained value, per unit time in a predetermined evaluation period, obtained by the extreme value obtaining step, and evaluates the conductive member based on a result in which the variation is compared to a previously defined standard variation value.