摘要 |
<p>A process unit which can be removably mounted in a main assembly of an electrostatographic copying machine has a housing enclosing an imaging member and, optionally, other processing means such as a development device, a cleaner, and a charge corotron. The transfer corotron, for transferring a toner image from the photoreceptor to a copy sheet is preferably incorporated in the cassette housing. An aperture is present in the housing adjacent corotron so that a copy sheet can enter the unit to have an image transferred thereto from the photoreceptor. A simple resilient cover flap is provided over the aperture which protects the imaging member from contamination, physical damage, and light exposure when the cassette is removed from the main assembly of the copier. The flap is readily displaced as an entering copy sheet bears against it, thus enabling a copy sheet to pass. As the trail edge of the copy sheet leaves the aperture the resilient flap reverts to its former position in which it closes the aperture until the arrival of a subsequent copy sheet. Instead of a resilient flap the cover may be formed by a brush.</p> |