Patent ID: 7024140
Filing Date: 2006-04-04
Classification: G03G

Abstract:
1. An electrophotographic image forming apparatus comprising: a photoreceptor; a charger configured to charge the photoreceptor; an irradiator configured to irradiate the photoreceptor with light to form an electrostatic latent image on the photoreceptor; an image developer configured to develop the electrostatic latent image with a developer comprising a toner comprising toner powders having an aggregation not greater than 20% and circularity not less than 0.93; and a toner feeder comprising a container configured to contain the toner prior to use in the developer, a pipe configured to transport the toner, and a pump configured to feed the toner from the container through the pipe, wherein the pump feeds the toner to the image developer through the pipe and comprises a screw pump having a female screw stator having a double-pitch spiral groove on an inner surface thereof, and a male rotor rotatably inserted into the female screw stator.