Image forming apparatus

An image forming apparatus capable of executing an image forming operation, comprising:

• a rotatable image bearing member on which an electrostatic latent image is formed;
• a developing device including a developing container configured to accommodate a developer containing toner and a carrier and including a developer carrying member configured to carry the developer for developing the electrostatic latent image, formed on the image bearing member, into a toner image;
• a transfer member onto which the toner image borne on the image bearing member is transferred;
• a carrier collecting device including a rotatable sleeve provided opposed to the image bearing member on a side, with respect to a rotational direction of the image bearing member, downstream of a developing position where the electrostatic latent image formed on the image bearing member is developed and upstream of a transfer position where the toner image borne on the image bearing member is transferred onto the transfer member, and including a magnet provided non-rotatably inside the sleeve, the carrier collecting device being configured to collect the carrier on the image bearing member;
• a voltage applying portion configured to apply a voltage to the sleeve;
• and
• a controller configured to control the voltage applying portion so that a carrier collecting bias such that a pulse portion where a DC voltage and an AC voltage are superposed with each other and a blank portion including only of the DC voltage are periodically repeated is applied to the sleeve when the image forming operation is executed.