Patent ID: 8831451
Filing Date: 2014-09-09
Classification: G03G

Abstract:
1. An image forming apparatus comprising: a developing device; an image carrier; and a density detection unit, wherein the developing device includes: a developer supporting rotator configured to magnetically support a two-component developer including at least a carrier and toner, on a surface of which a magnetic brush is formed by the carrier included in the two-component developer; a toner supporting rotator arranged opposite to the developer supporting rotator and configured to support the toner supplied from the developer supporting rotator and to form a toner layer by the magnetic brush; a voltage application unit configured to apply a first bias voltage to the developer supporting rotator and a second bias voltage to the toner supporting rotator in order to apply a developing bias voltage between the toner supporting rotator and the image carrier, such that the toner supported by the toner supporting rotator flies to an electrostatic latent image on a surface of the image carrier and develops the electrostatic latent image into a toner image; a voltage control unit configured to control a voltage difference between the first bias voltage and the second bias voltage applied by the voltage application unit; a toner layer formation control unit configured to instruct the voltage control unit to set the voltage difference to a first voltage difference at which the toner is bidirectionally movable between the developer supporting rotator and the toner supporting rotator and the toner layer is formed on a surface of the toner supporting rotator; and a stripping control unit configured to instruct the voltage control unit to set the voltage difference to a second voltage difference at which a substantially entire amount of toner composing the toner layer formed on the toner supporting rotator moves to the developer supporting rotator, in a toner layer stripping mode where the toner layer formed on the surface of the toner supporting rotator is stripped during rotation of the toner supporting rotator, wherein an electrostatic latent image is formed on a surface of the image carrier and a toner image is formed on the electrostatic latent image by the toner supplied from the toner layer of the developing device, wherein the density detection unit detects density of toner at any one of the surface of the image carrier, a transfer member onto which the toner image is primarily transferred from the image carrier, and a conveyance member that conveys a sheet of recording medium to which the toner image is transferred from the image carrier, and wherein the stripping control unit outputs an instruction for adjusting the second voltage difference to the voltage control unit, such that the toner flies to the surface of the image carrier and the density is decreased based on the density detected by the toner density detection unit, for a case where the toner remains on the surface of the toner supporting rotator in the toner layer stripping mode.