Developer carrying member, developing device unit

A developing device for developing an electrostatic image comprising a developer carrying member for carrying and feeding a developer and a developer layer thickness control member for controlling a layer thickness of the developer carried on the developer carrying member, said developer carrying member comprising a substrate and a coating film, wherein the surface of said substrate is covered with said coating film, and said coating film is formed by coating with a coating solution containing (a) separately dispersed therein (i) a graphite, a carbon black or a mixture thereof, and (ii) a spherical resin particle having a number average particle diameter of from 0.05 to 30.mu. and the ratio of major axis to minor axis of said spherical resin particle is from 1.0 to 1.5, and (b) a film-forming binder resin dissolved in said coating solution, said spherical resin particle providing a surface of said coating film with roughness.

A device unit comprising a developing means and a photosensitive member which are integrally held to form a unit that gives a single unit capable of being freely mounted on and detached from an apparatus main body, said developing means comprising a developer carrying member, and said developer carrying member comprising a substrate and a coating film, wherein the surface of said substrate is covered with said coating film, and said coating film is formed by coating with a coating solution containing (a) separately dispersed therein (i) a graphite, a carbon black or a mixture thereof, and (ii) a spherical resin particle having a number average particle diameter of from 0.05 to 30.mu. and the ratio of major axis to minor axis of said spherical resin particle is from 1.0 to 1.5, and (b) a film-forming binder resin dissolved in said coating solution, said spherical resin particle providing a surface of said coating film with roughness.