Developing device for use in electrophotography

Claim 1

In an electrostatic latent image developing device having a pair of spaced magnet rolls for delivery of developer from a developer storage chamber to the latent image bearing surface of an electrostatic recording medium, and wherein each magnet roll is comprised of a fixed magnetic body having a plurality of magnetic poles and surrounded by a rotatable tube of nonmagnetic material, one of said magnet rolls being a developer magnet roll and positioned adjacent said electrostatic recording medium to deposit developer thereon, the improvement comprising: means for separating unused developer from the developer roll comprising a first magnetic pole on said developer roll spaced from the electrostatic recording medium in the direction of rotation of the rotatable tube associated with the developer roll, a second magnetic pole on the other side roll opposite in polarity to said first magnetic pole for attracting unused developer to said second magnetic pole, said other magnetic roll being in position to deliver the unused, separated developer to a housing compartment.