Electrostatic copying apparatus.

摘要

An electrostatic copying apparatus comprising a housing (2) having a rotary drum (12) mounted rotatably therewith which has a photosensitive member (70) on its peripheral surface. An original-support mechanism (4) is disposed on the top surface of the housing and includes a transparent plate for receiving an original document to be copied. A charging corona-discharge device (22) for applying corona discharge to the photosensitive member in a latent electrostatic image-forming zone is located along the peripheral surface of the rotary drum. An optical unit (32) is disposed above the rotary drum within the housing for projecting the image of the original document placed on the transparent plate onto the photosensitive member in the latent electrostatic image-forming zone. A copying paper transfer unit (46) transfers a copying paper through a transfer passage which extends from one end portion of the housing (2) to its other end in the lower portion of the housing through a transfer zone located below the rotary drum. A fixing mechanism (58) is disposed downstream of the transfer zone within the transfer passage and includes an electric heater (202). A partitioning wall (228) divides the interior of that part of the housing lying on the side of the rotary drum facing said other end of the housing into an upper portion containing the optical unit (32) and a lower portion containing the fixing mechanism (58). The upper portion of the housing also contains a first fan (230) which is drivingly connected to the main electric motor (232) which is itself also drivingly connected to the rotary drum (12). A second fan (240) is disposed so as to bridge said upper and lower portions of the housing and is drivingly connected to another, auxiliary motor (242). The second fan (240) is adapted to discharge air from the upper and lower housing portions through said other end of the housing. The arrangement is such that, when a main power control switch of the electrostatic copying apparatus is closed, an energising current is supplied to the electric heater of the fixing mechanism (58) and, simultaneously, an energising current is supplied to the auxiliary motor (242) to drive the second fan (240). An energising current for the main electric motor (232) is then initiated only upon subsequent initiation of an actual copying process.