Dual mode image forming apparatus

An image forming apparatus comprising:

• an image bearing member for bearing a toner image;
• an intermediary transfer member;
• voltage application means for applying a voltage to said intermediary transfer member to electrostatically transfer the toner image from said image bearing member onto said intermediary transfer member at an image transfer position, the toner image transferred onto said intermediary transfer member being transferred onto a transfer material;
• wherein said apparatus is operable selectively in a first mode in which toner images of different colors are sequentially and superposedly transferred from said image bearing member onto said intermediary transfer member by said voltage application means, and are then transferred onto the transfer material, and in a second mode in which only a toner image of a first color of the different colors is transferred onto said intermediary transfer member from said image bearing member by said voltage application means, only the toner image of the first color being transferred onto the transfer material;
• wherein an absolute value of the voltage applied to said intermediary transfer member by said voltage application means is larger when said second mode is selected than when said first mode is selected, when the toner image of said first color is transferred from said image bearing member onto said intermediary transfer member.