Patent ID: 9217984
Filing Date: 2015-12-22
Classification: G03G

Abstract:
1. An image carrier unit comprising: an image carrier on which a toner image is formed; a cleaning roller rotating while making contact with the image carrier to collect a residual toner remaining on a circumferential surface of the image carrier; a conveyance member receiving the residual toner collected by the cleaning roller, and conveying the residual toner towards a one-end part side in a rotation-axis direction of the cleaning roller; and an operating mechanism making the cleaning roller perform thrust operation in the rotation-axis direction of the cleaning roller, wherein the operating mechanism includes: a coupling gear engaging with a rotational driving gear providing a rotational driving force, and also being coupled to a rotating shaft of the cleaning roller in a manner such as to be capable of rotating together therewith; a pressing member pressing the coupling gear and the cleaning roller to the one-end part side of the cleaning roller in the rotation-axis direction; and a freely fitting gear being located closer to the one-end part side in the rotating-axis direction than the coupling gear, being freely fitted to the rotating shaft of the cleaning roller in a state in which a movement thereof in the rotation-axis direction at a position opposing the coupling gear is regulated, also engaging with the rotational driving gear, and rotating at a rotation speed different from a rotation speed of the coupling gear in a number of teeth different from a number of teeth of the coupling gear, and at each of opposing side surface parts on the coupling gear and the freely fitting gear arranged oppositely to each other, a bumpy shape formed of a convex part and a concave part whose height in the rotation-axis direction varies continuously is formed along a circumferential direction with the rotation-axis as a center.