Disclosed in the present invention is a process
cartridge, comprising: a photoconductor drum, wherein an electrostatic
latent image can be formed on the photoconductor drum; a developer accommodating chamber for accommodating a developer therein; a rotatable developer roller, wherein the axial direction of the developer roller extends in the length direction, and the developer roller is configured to transfer the developer to the photoconductor drum to develop the electrostatic
latent image on the photoconductor drum; a rotatable toner supply roller, wherein the axial direction of the toner supply roller extends in the length direction, and the toner supply roller is in contact with the developer roller to supply the developer to the developer roller; a developing chamber, wherein the developer roller is located in the developing chamber, and when the process
cartridge is mounted to an
electronic imaging device, the developing chamber is located above the developer accommodating chamber; and a developing
coupling which receives a driving force to enable the developer roller and the toner supply roller to rotate, and when the developer roller and the toner supply roller are driven to rotate, the
peripheral speed of the surface of the toner supply roller is smaller than or equal to the
peripheral speed of the surface of the developer roller. The solution ensures stable driving of the developer roller, the toner supply roller, etc., in a developing unit.