Patent ID: 9092000
Filing Date: 2015-07-28
Classification: G03G

Abstract:
1. A cleaning unit comprising: a cleaning member eliminating a waste toner from an image forming face of an image carrier forming a toner image; a waste toner conveying body conveying the waste toner in a conveying channel arranged in a casing supporting the cleaning member to a waste toner case; a cylindrical shutter having an openable/closable ejecting port making the conveying channel and waste toner case communicate with each other and being able to contact with/separate from a seal preventing a leak of the waste toner from the ejecting port; a shutter moving mechanism moving the shutter between an opening position and a closing position, wherein, when the shutter is rotated in one direction around an axis, and simultaneously, moved in an axial direction so as to make an outer end face of the shutter contact with the seal, the shutter is located at the opening position and the ejecting port is opened, while, when the shutter is rotated in another direction around the axis, and simultaneously, moved in the axial direction so as to make the outer end face of the shutter separate from the seal, the shutter is located at the closing position and the ejecting port is closed; and a conveying body moving mechanism interlocking with the movement of the shutter by the shutter moving mechanism to move the waste toner conveying body in an axial direction in the same direction as the shutter, wherein the waste toner conveying body is a screw extending along the conveying channel, the casing has a case side bearing part rotatably supporting an upstream end part of the waste toner conveying body, an inside end face of the shutter has a shutter side bearing part rotatably supporting a downstream end part of the waste toner conveying body, the shutter moving mechanism includes: an oblique groove obliquely formed in a circumference wall of the shutter so as to move the shutter between the opening position and closing position; a protrusion formed in an outer circumference face of the casing so as to engage with the oblique groove; a torsion coil spring applying a biasing force to the shutter so as to move the shutter to the closing position; and a lever protruded in a radial direction from a circumference face of the shutter and manipulated so as to move the shutter to the opening position against the biasing force of the torsion coil spring, the conveying body moving mechanism includes: a drive gear driving and rotating the image carrier; and a following gear meshing with the drive gear and applying a thrust loading to the waste toner conveying body so as to move the shutter to the opening position when the drive gear is driven, the drive gear and following gear are composed of respective helical gears, in the inside end face of the shutter, a slope-like inclined part is formed to be inclined in the same direction and at the same angle as the oblique groove, and the inclined part is formed to come into contact with a downstream end face of the casing.