Patent ID: 7412194
Filing Date: 2008-08-12
Classification: G03G

Abstract:
1. A developing apparatus, comprising: a rotatable development roller that supplies a two-component developer comprising a toner and a carrier to a rotatable electrostatic latent image bearing member having an electrostatic latent image formed on a surface, and converts the electrostatic latent image into a visible image; a stationary magnet roller that is provided in the development roller, comprises a development main pole and at least a pair of magnetic poles of the same polarity for detaching the developer, and has a midpoint between the magnetic poles of the same polarity on the development roller that is positioned above a rotation shaft of the development roller; a first developer transport path and a second developer transport path that extend in parallel to the development roller; a first developer transporter that is mounted for rotation in the first developer transport path, and transports the two-component developer along a first developer transport direction by rotation; and a second developer transporter that is disposed in the second developer transport path, has a rotation shaft positioned above the rotation shaft of the development roller, transports the two-component developer in a second developer transport direction which is opposite to the first developer transport direction by rotation, supplies the two-component developer to the development roller and detaches the two-component developer from the development roller, wherein a relationship is satisfied, where r (mm) denotes a rotational radius of the second developer transporter, R (mm) denotes a rotational radius of the development roller, and d (mm) denotes a center distance between the second developer transporter and the development roller, and a relationship is satisfied, where mg0 (g/mm v (mm/s) denotes a rotational peripheral velocity of the electrostatic latent image bearing member, l (mm) denotes a maximum printing width of the electrostatic latent image bearing member, and M0 (g/s) denotes an amount of the developer transported per unit time by the second developer transporter in the second developer transport direction.