Patent ID: 8107834
Filing Date: 2012-01-31
Classification: G03G

Abstract:
1. An image forming apparatus comprising: an image carrying member to carry a toner image; a transfer member to make contact with the image carrying member to transfer the toner image onto a sheet from the image carrying member; an opposite member facing the transfer member across the image carrying member; current applying means to apply a predetermined current to the transfer member or the opposite member when there is not the sheet at a transfer position; voltage detecting means for detecting a voltage generated at the transfer position when there is not the sheet at the transfer position by applying the predetermined current to the transfer member or the opposite member by the current applying means; first calculating means for calculating a transfer member correction voltage on the basis of the voltage detected by the voltage detecting means; sheet detecting means for detecting a kind of the sheet; humidity detecting means for detecting intra-apparatus humidity; second calculating means for calculating a sheet correction voltage on the basis of the detected sheet kind and the detected intra-apparatus humidity; transfer bias voltage deciding means for calculating a transfer bias voltage by adding the transfer member correction voltage calculated by the first calculating means and the sheet correction voltage calculated by the second calculating means; and transfer bias voltage applying means for applying the transfer bias voltage decided by the transfer bias voltage deciding means to either of the transfer member and the opposite member so as to transfer the toner image onto the sheet from the image carrying member.