IMAGE FORMING APPARATUS

An image forming apparatus includes a developing device including a developer carrying member, a developer supplying member and a regulating member; a first power source for the developer carrying member; a second power source for the regulating member; and a controller. In a period from a start of a developing operation to an end of the developing operation for a same recording material, the controller effects control of providing a potential difference between the developer carrying member and the developing blade so that a force for urging the developer from the regulating member toward the developer carrying member acts on the developer at a contact portion between the regulating member and the developer carrying member, the force acting on the developer being stronger at a time of the end of the developing operation than at a time of the start of the developing operation.