| 摘要 |
PROBLEM TO BE SOLVED: To prevent a current from flowing reversely to cause malfunction and damage to a power supply board, when switching a transfer mode.SOLUTION: An image forming apparatus which can switch between a DC transfer mode for applying a transfer bias by a DC voltage to perform an image transfer and a superposing transfer mode for applying a transfer bias obtained by superposing an AC voltage on a DC voltage to perform the image transfer, comprises: a DC power supply 201 for applying a DC transfer bias, and an AC power supply 202 for applying a superposing transfer bias. When switching a transfer mode, the apparatus switches the transfer mode in a state in which the DC power supply and the AC power supply are turned off. |
