IMAGE FORMING APPARATUS AND METHOD WITH CONTROL OF ELECTROSTATIC TRANSFER USING CONSTANT CURRENT

摘要

An electrostatographic recording apparatus and method includes a primary charger that establishes a uniform electrostatic charge on the image recording member in accordance with a first operating parameter. A recording device that imagewise modulates the charge on the image recording member to form electrostatic images in accordance with a second operating parameter and additionally forms a developable process control patch. A development station develops the electrostatic images and the control patch on the image recording member with toner in accordance with a third operating parameter. A transfer station transfers developed images from the image recording member. The transfer station includes a transfer member and power supply providing to the transfer member a transfer current used for transferring developed images. In one embodiment a sensor senses density of the developed control patch. A controller in response to density of the control patch provides adjustments to the first, second and third operating parameters and controls the power supply to provide to the transfer member transfer current as a function of a parameter related to one of the first, second or third operating parameters. In other embodiments transfer current can be determined in response to other more direct measures of charge to mass ratio in the development station.