Patent ID: 7769313
Filing Date: 2010-08-03
Classification: G03G

Abstract:
1. A charging device comprising: a linear electrode; a cleaning member mounted so as to be in contact with the electrode; a rotatable screw gear positioned along a length of the electrode; a motor for rotating the screw gear in forward and reverse directions; a support for holding the cleaning member, the support being mounted unrotatably but reciprocably between a first end and a second end of the electrode; and a protruding member that extends perpendicular to the length of the electrode from the support, the protruding member having a projection that is elastically fitted into a thread groove of the screw gear along a radial direction of the screw gear, wherein the direction of twist of the threads of the screw gear is configured in such a manner that a distance between a starting point of elastic deformation of the protruding member and a contact point between the projection and a thread of the screw gear is smaller when the support is moved forward away from a home position than when the support is moved backward toward the home position, and wherein the protruding member is sufficiently flexible such that when the support is prevented from moving and the rotatable screw gear continues to rotate, the projection is allowed to ride over the top of the threads while the protruding member elastically flexes.