Inventors:
Larry W. Speer - Hilton NY
International Classification:
G03G 1509
Abstract:
An improved magnetic brush development apparatus for applying developer material to a latent electrostatic image wherein measurement of toner level is facilitated. The apparatus includes a housing defining a sump portion adapted to contain a supply of developer material, and a magnetic brush located substantially within the housing in spaced relation to the sump portion for applying developer material to the latent image. A feed mechanism located within the housing between the sump portion and the magnetic brush transports developer material from the sump to the magnetic brush, and a mechanism located in the sump portion agitates developer material and transports developer material to the feed mechanism. Developer material in the sump portion is replenished by a device which includes a reservoir for replenishment material adjacent to the sump portion, a flow communication path between the reservoir and the sump portion, and a device for selectively controlling flow of replenishment material through the path. Measuring the level of replenishment material in the reservoir is facilitated by a material monitor located in the bottom of the reservoir immediately upstream of the flow communication path, the surface of the monitor being periodically swept to assure accurate measurement of replenishment material level.