Patent ID: 9235165
Filing Date: 2016-01-12
CPC Classification: G03G

Claim Text:
1. An image forming apparatus comprising: an intermediary transfer belt; a transfer member configured to transfer a toner image from said intermediary transfer belt onto a transfer material at a transfer portion; a power supply configured to apply a transfer voltage to said transfer member; a first cleaning member configured to contact with a surface of said intermediary transfer belt at a first cleaning portion to collect toner passed through the transfer portion, a first voltage having an identical polarity to a toner charge polarity being applied to said first cleaning member; a second cleaning member configured to contact with the surface of said intermediary transfer belt at a second cleaning portion to collect the toner passed through the transfer portion, a second voltage having an opposite polarity to the toner charge polarity being applied to said second cleaning member; a first detecting member configured to detect a first current passing through said first cleaning member; a second detecting member configured to detect a second current passing through said second cleaning member; a memory configured to store information about detection results of said first detecting member and said second detecting member; and a control portion, capable of executing an adjusting mode, configured to detect the first current and the second current using said first and second detecting members, respectively, and configured to adjust the transfer voltage on the basis of detection results of said first and said second detecting members and the information from said memory stored in a previous adjusting mode, the transfer voltage being adjusted to a lower voltage in a case of a first decrease amount being greater than a second decrease amount, and the transfer voltage being adjusted to a higher voltage in a case of the second decrease amount being greater than the first decrease amount, the first decrease amount being a value obtained by subtracting an absolute value of the first current detected in the adjusting mode from an absolute value of the first current detected in the previous adjusting mode, the second decrease amount being a value obtained by subtracting an absolute value of the second current detected in the adjusting mode from an absolute value of the second current detected in the previous adjusting mode.