DEVELOPING ROLLER HAVING INSULATING AND CONDUCTIVE AREAS

摘要

A method and apparatus for developing a latent image electrostatically formed on an image carrier by a developer carried on a developer carrier in a developing region where the image carrier and the developer carrier are located face-to-face. A great number of electric fields are produced on the surface of the developer carrier. An electric field is produced by a voltage applying device in the developing region. The movement of the developer is controlled by an electric field determined by the relationship between a potential deposited on the image carrier, a potential deposited on the developer carrier, and the electric field produced by the voltage applying device. A large number of first and second areas are formed on the surface of the developer carrier such that the first areas are charged to a predetermined potential and the second areas as set at a potential which is lower than the predetermined potential of the first areas in order to generate different level electric fields in the first and second areas. With this arrangement, higher quality images having constant density are formed as a well-balanced charging/discharging condition is developed between the toner and the toner supply roller of the device.