Image forming apparatus provided with a photosensitive member having a photosensitive layer and a surface protection layer which is formed on the surface of the photosensitive layer and which has a hardness higher than that of the photosensitive layer

An image forming apparatus comprising:

• a photosensitive member having a photosensitive layer and a surface protection layer which is formed on a surface of the photosensitive layer and which has a hardness higher than a hardness of the photosensitive layer;
• a charging member which electrostatically charges the photosensitive member;
• an exposing device which forms an electrostatic latent image on a surface of the photosensitive member having been electrostatically charged by the charging member;
• a developing device having a toner carrying member which carries thereon toner containing polishing particles, the developing device feeding toner from the toner carrying member to the photosensitive member and thereby developing the electrostatic latent image into a toner image;
• a transfer member which transfers the toner image formed on the photosensitive member to a recording medium;
• a polishing member having an elastic layer on a circumferential surface thereof in contact with the photosensitive member, the polishing member polishing the surface of the photosensitive member while rotating in contact with the photosensitive member with a linear velocity difference from a linear velocity of the photosensitive member;
• a driving device which drives the polishing member to rotate;
• a voltage applying device which applies voltages to the charging member, the toner carrying member, and the transfer member respectively;
• a torque detector which detects a torque of the driving device observed when the polishing member is driven to rotate;
• and
• a control portion which estimates an attachment condition of discharge products to the surface of the photosensitive member based on the torque of the driving device detected by the torque detector, wherein
• when the torque of the driving device detected by the torque detector is equal to or higher than a predetermined value, the control portion performs an image degradation suppression process to prevent degradation of image quality resulting from the discharge products.