Patent ID: 6859633

Claim:
An integral-type process cartridge comprising: a latent-image-bearing member configured to hold thereon an electrostatic latent image; and developing means for rendering visible the electrostatic latent image held on said latent-image-bearing member, by means of a non-magnetic one-component developer to form a toner image, said developing means comprising: a developer container configured to hold therein said developer and including a bottom part having two concave portions, and an inner wall; a developer agitation and transport member configured and positioned to agitate said developer held in said developer container, said developer agitation and transport member comprising at least two rotary agitation and transport means for agitating and transporting said developer having rotating shafts and agitation blades; a developing member configured and positioned to perform development with the developer in pressure contact with said latent-image-bearing member; and a control member configured and positioned to control the quantity of said developer on said developing member, wherein said rotating shafts extend at right angles to a vertical cross section which bisects, in said process cartridge, the surface of said latent-image-bearing member with which said developing member is brought into pressure contact, wherein said agitation blades rub said inner wall of said developer container, wherein said two concave portions in said bottom part of said developer container are opposite to said rotating shafts, wherein the cross sectional area of said developer container at the vertical cross section is represented by S1, wherein the cross sectional area of the part of said developing means corresponding to a movable region of said two rotary agitation and transport means at the vertical cross section is represented by S2, and wherein the ratio S2/S1 is from 0.8 to 0.99, wherein a minimum-area circumparallelogram of area S1 has a long side Sa and a short side Sb, wherein the ratio Sa/Sb is from 1.5 to 3.0, and wherein said non-magnetic one-component developer contains at least a binder resin and a colorant and has a fluidity index of from 50 to 90 and a floodability index of from 45 to 96.