Transfer member cleaning method and image forming apparatus

An image forming apparatus for forming an image by charging a surface of a photosensitive body being driven and then exposing the surface to light to form an electrostatic latent image, developing the electrostatic latent with toner having same polarity as a charge polarity of the surface of the photosensitive body to form a toner image, and transferring the toner image from the photosensitive body to a transfer material by driving the photosensitive body and a roller or belt-shaped transfer member while pressing the transfer material, comprising:

• a first voltage applying unit for applying a first voltage having same polarity as an electric potential to which the surface of the photosensitive body is charged and an absolute value larger than the electric potential to the transfer member for a first period of time when image formation is not performed;
• and
• a second voltage applying unit for applying a second voltage having an absolute value smaller than the absolute value of the electric potential to which the surface of the photosensitive body is charged to the transfer member for a second period of time, which is not shorter than the first period of time, when image formation is not performed,
• wherein the transfer member is cleaned by the first voltage applying unit and the second voltage applying unit.

An image forming apparatus comprising:

• a photosensitive body;
• a charging device for charging a surface of the photosensitive body being driven;
• an exposure device for exposing the surface of the photosensitive body to light to form an electrostatic latent image;
• a developer device for developing the electrostatic latent image with toner having same polarity as a charge polarity of the surface of the photosensitive body to form a toner image;
• a roller or belt-shaped transfer member for transferring the toner image from the photosensitive body to a transfer material by pressing the transfer material between the photosensitive body and the transfer member;
• a first voltage applying unit for applying a first voltage having same polarity as an electric potential to which the surface of the photosensitive body is charged and an absolute value larger than the electric potential to the transfer member for a first period of time when image formation is not performed;
• and
• a second voltage applying unit for applying a second voltage having an absolute value smaller than the absolute value of the electric potential to which the surface of the photosensitive body is charged to the transfer member for a second period of time, which is not shorter than the first period of time, when image formation is not performed.