Patent ID: 8126371

Claim:
A developing device comprising: a developer receptacle for storing a developer containing a toner and a magnetic carrier; a developer conveying passage through which the developer is conveyed; a developer conveying member disposed inside the developer conveying passage to agitate and convey the developer in a predetermined direction; a developer supporting member which supports the developer in the developer conveying passage to supply the toner contained in the developer to a photoreceptor drum; a toner supply port for taking a supply of the toner into the developer conveying passage; and, an electromagnet provided at the outer periphery of the toner supply port, and wherein the toner supply port is formed over the developer conveying member, and the electromagnet intermittently attracts the developer residing under the toner supply port; and further including a developer receptacle cover provided on the top of the developer receptacle, wherein the toner supply port is formed in the developer receptacle cover, the developer receptacle cover includes a developer retreat that is projected upward to form a space capable of holding the developer inside the developer receptacle, the developer retreat is formed at the outer periphery of the toner supply port, and the electromagnet is arranged at such a position as to form a magnetic field in the space of the developer retreat.