Patent ID: 6219513
Filing Date: 2001-04-17
Classification: G03G

Abstract:
A developing device for supplying a developing agent, formed of a mixture of a toner and a carrier, to an electrostatic latent image, formed on an outer peripheral surface of an image carrier, and visualizing said electrostatic latent image with said toner, the developing device comprising:a developing sleeve opposed to the outer peripheral surface of said image carrier and capable of rotating with said developing agent held on an outer peripheral surface thereof, thereby transporting said developing agent to said electrostatic latent image;a magnet roller located for rotation in the developing sleeve and having a plurality of magnetic poles for generating a given magnetic force on the outer peripheral surface of said developing sleeve, arranged in the rotating direction thereof; anddeveloping bias applying means for applying a given developing bias between said image carrier and the developing sleeve to supply the toner in the developing agent held on the outer peripheral surface of said developing sleeve to the electrostatic latent image formed on the outer peripheral surface of said image carrier,wherein A>280 is fulfilled where A is given by:A=.vertline.Rs.times..omega.m-Rd.times..omega.d.vertline..times.P.times.Vs. times.T/Vp,where Rs (mm) is the radius of said developing sleeve, .omega.m (rpm) is the rotational frequency of said magnet roller, Rd (mm) is the radius of said image carrier, .omega.d (rpm) is the rotational frequency of said image carrier, P is the number of magnetic poles of said magnet roller, Vs (mm/sec) is the peripheral speed of the outer peripheral surface of said developing sleeve, T is a magnetic flux density on the outer peripheral surface of said developing sleeve, and Vp (mm/sec) is the peripheral speed of the outer peripheral surface of said image carrier.