Patent ID: 6924076

Claim:
A process cartridge comprising: a latent-image-bearing member configured to hold thereon an electrostatic latent image; charging means for charging said latent-image-bearing member electrostatically; and a developing assembly configured and positioned to develop the electrostatic latent image formed on said latent-image-bearing member, by the use of a developer to form a developer image, said developing assembly and said latent-image-bearing member being set to be integral as one unit and being so constructed as to be detachably mountable to a main body of an image forming apparatus, said developer comprising: toner particles containing at least a binder resin and a colorant; and conductive fine particles, said toner particles having a Circularity a of less than 0.970 as found from the following expression: Circularity a=L 0 /L, where L 0 represents the circumferential length of a circle having the same projected area as a toner particle image, and L represents the circumferential length of a projected image of a toner particle, said developing assembly comprising at least: a developing container configured to hold therein the developer; a developer-carrying member configured and positioned to hold thereon the developer held in said developing container and to transport the developer to a developing zone, said developer-carrying member comprising at least: a substrate; and a resin coat layer formed on said substrate, said resin coat layer containing at least a coat layer binder resin and a positively chargeable material; and a developer layer thickness regulation member configured and positioned to regulate the layer thickness of the developer to be held on said developer-carrying member, wherein said developing assembly performs development of the electrostatic latent image formed on said latent-image-bearing member, by the use of the developer to render the electrostatic latent image visible as the developer image, and at the same time collects the developer having remained on said latent-image-bearing member after the developer image has been transferred to a recording medium transfer sheet, and wherein said charging means is kept in contact with said latent-image-bearing member at a contact part thereof, and charges said latent-image-bearing member electrostatically upon application of a voltage to the contact part in the state where said conductive fine particles of said developer are interposed between said charging means and said latent-image-bearing member at least at the contact part.