US 2003/0118374 A1 · Developing apparatus and method in image forming apparatus

Abstract

A developing apparatus in an image forming apparatus includes a retrieving/auxiliary developing roller being in contact with the circumference of the photosensitive drum to retrieve or collect toner remaining on a region other than an image region of the circumference of the photosensitive drum and to first develop the latent electrostatic image, a first toner layer control member uniformly re-distributing the remnant toner and electrifying toner on the circumference of the retrieving/auxiliary developing roller a a developing roller having a gap with the circumference of the photosensitive drum to secondly develop the firstly developed latent electrostatic image so as to completely visualize the latent electrostatic image, a supply roller supplying toner to the developing roller, and a second toner layer control member for regularly coating the toner, which is supplied by the supply roller, throughout the circumference of the developing roller and controlling the amount of the electrification of the toner of the developing roller. The toner remaining along the circumference of a photosensitive drum is retrieved and collected to be used in developing a latent electrostatic image.

Claims18

Dependent claims

A developing apparatus in an image forming apparatus having a photosensitive drum with a non-image region, on which a latent electrostatic image is not formed, and an image region, on which the latent electrostatic image is formed, the developing apparatus comprising:

a retrieving/auxiliary developing roller being in contact with a circumference of the photosensitive drum, retrieving toner remaining on the non-image region of the circumference of the photosensitive drum on which the latent electrostatic image is not formed, and first developing the image region of the latent electrostatic image;
a first toner layer control member uniformly re-distributing and electrifying the retrieved toner on a circumference of the retrieving/auxiliary developing roller;
a developing roller having a gap with the circumference of the photosensitive drum, secondly developing the firstly developed latent electrostatic image so as to completely visualize the latent electrostatic image;
a supply roller supplying new toner to the developing roller;
and
a second toner layer control member regularly coating the toner supplied by the supply roller throughout the circumference of the developing roller, and regulating the amount of electrification of the new toner coated on the developing roller.

3 more elements

A method of forming an image in a developing apparatus of an image forming apparatus, which includes a retrieving/auxiliary developing roller primarily developing a latent electrostatic image while retrieving toner remaining around the latent electrostatic image formed on a circumference of a photosensitive drum, a developing roller developing and visualizing the latent electrostatic image while keeping a predetermined gap with a circumference of the photosensitive drum, and a supply roller supplying toner to the developing roller, wherein the circumference of the photosensitive drum is charged with a first electric potential in response to an image forming initial signal, and then an image region of the circumference of the photosensitive drum is charged with a second electric potential to form the latent electrostatic image, and a third electric potential is applied on the circumference of the retrieving/auxiliary developing roller, and wherein the first through third electric potentials have a following relationship:

|second electric potential|<|third electric potential|<|first electric potential|.

Dependencies are inferred from the claim text.

Developing apparatus and method in image forming apparatus

Life of this patent

Developing apparatus and method in image forming apparatus

Life of this patent

Abstract

Claims18