Developer stirring device and developing device and image forming apparatus using the same

A developing device comprising:

• stirring paths disposed parallel to each other and communicating with each other through communicating ports at lengthwise opposite ends and intermediate portions remote from the opposite ends of said stirring paths;
• a toner supplier for supplying toner to one of said stirring paths;
• stirring screws respectively disposed in said stirring paths for stirring and conveying a developer from one of said stirring paths to the other through said communicating ports by rotation of said stirring screws;
• and
• a developing roller for receiving said developer during conveyance through the other of said stirring paths,
• wherein one of said stirring screws comprises delivering means for scooping and delivering said developer to the other said stirring screws by the rotation thereof, said delivering means facing said communicating port, at the intermediate portion, and
• the other of said stirring screws comprises distributing means for receiving said developer from said delivering means and distributing said developer toward the opposite ends by the rotation thereof, said distributing means facing said communicating port at the intermediate portion.

An image forming apparatus comprising:

• stirring paths disposed parallel to each other and communicating with each other through communicating ports at lengthwise opposite ends and intermediate portions remote from the opposite ends of said stirring paths;
• a toner supplier fox supplying toner to one of said stirring paths;
• stirring screws respectively disposed in said stirring paths for stirring and conveying a developer from one of said stirring paths to the other through said communicating ports by rotation of said stirring screws;
• a developing roller for receiving said developer during conveyance through the other of said stirring paths;
• and
• a photosensitive drum disposed so as to oppose said developing roller for visualizing an electrostatic latent image formed thereon by transferring said developer onto a surface thereof,
• wherein one of said stirring screws comprises delivering means for scooping and delivering said developer to the other of said stirring screws by the rotation thereof, said delivering means facing said communicating port at the intermediate portion, and
• the other of said stirring screws comprises distributing means for receiving said developer from said delivering means and distributing said developer toward the opposite ends by the rotation thereof, said distributing means facing said communicating pool at the intermediate portion.