Patent ID: 9031434
Filing Date: 2015-05-12
Classification: G03G

Abstract:
1. An image forming apparatus comprising: an image bearing member on which an electrostatic image is to be formed; a developer carrying member for carrying a developer including a toner and a carrier to develop the electrostatic image on said image bearing member; a first chamber for permitting feeding of the developer to said developer carrying member; a second chamber, provided at a position different in height from said first chamber, for forming a circulation path of the developer by communicating with said first chamber at end portions thereof, wherein said second chamber collects the developer from said developer carrying member at an opposing position to said developer carrying member; a first screw member for feeding the developer contained in said first chamber; a second screw member for feeding the developer contained in said second chamber; a supplying portion for supplying a developer including a toner and a carrier to compensate for the toner consumed by image formation; a discharging portion, provided in the circulation path, for causing an excessive developer to overflow; and a controller for for effecting control so that when a first drive time from a start of rotation of said first screw member to an end of an image forming operation of a final image in a print job is shorter than a predetermined time, compared with when the first drive time is longer than the predetermined time, a second drive time from the end of the image forming operation of the final image in the print job to a stop of the rotation of said first screw member is longer during the print job.