Patent ID: 6546222
Filing Date: 2003-04-08
Classification: G03G

Abstract:
A developing apparatus for an image forming apparatus includes means for forming an electrostatic latent image corresponding to an image information signal on an image bearing member, said developing apparatus comprising:a developer carrying member which bears and conveys a two-component developer containing a non-magnetic toner and a magnetic carrier for forming a toner image by developing the electrostatic latent image formed on the image bearing member, wherein convexities and concavities are formed on a surface of said developer carrying member, and an average peak-to-peak spacing (Sm) of the convexities and concavities is set at &frac13; to 6 times a weight-average particle diameter of the magnetic carrier (D) (D/3&lE;Sm &lE;6*D), wherein an average roughness at ten points (Rz) on the surface of said developer carrying member is set at {fraction (1/10)} to Â½ times the weight-average particle diameter of the magnetic carrier, wherein a number of concavities which are 1 &mgr;m to 10 &mgr;m wide and 0.2 &mgr;m or more deep is smaller than 10 within a spacing of 100 &mgr;m in a surface profile of said developer carrying member, and wherein the surface of said developer carrying member is a blasted surface prepared by blasting the surface of said developer carrying member with definite spherical particles having a weight-average diameter d and a weight-average particle diameter D of the magnetic carrier, according to the following relation: D&lE;d&lE;10D.