regulation of the development of the elektrografischen printer or kopierers and a development unit for such a system

摘要

A printer or copier has a developer station for a toner image wherein a photoconductive drum is provided with a latent charge image that is developed by applying a toner/air mixture to a developer drum that in turn applies the toner to the photoconductive drum. The toner is charged by a charging device as it is applied to the developer drum. A sensor senses the toner on the developer drum and a control varies the quantity of toner applied. The sensor is an optical sensor or a capacitive sensor, and the charge applied to the toner by the charging device is varied depending on the sensor output. A voltage applied to the developer drum may also be varied.