Trim bar entry geometry for a dual component development electrophotographic image forming device

摘要

A developer unit for a dual component development electrophotographic image forming device according to one example embodiment includes a housing having a reservoir for storing a developer mix that includes toner and magnetic carrier beads. An auger is positioned to convey developer mix in the reservoir toward the outer surface of a magnetic roll on a front of the housing. A ledge on an inner surface of the housing extends axially with respect to the magnetic roll along a front of the reservoir. The ledge is positioned upstream from a trim bar and downstream from a pickup pole of the magnetic roll with respect to the operative rotational direction of the magnetic roll. The ledge has a concave curved inner surface that is open to the reservoir and extends from near the trim bar to near a front side of the auger.

主权项

1. A developer unit for a dual component development electrophotographic image forming device, comprising:
a housing having a reservoir for storing a developer mix that includes toner and magnetic carrier beads; a magnetic roll on a front of the housing, the magnetic roll including a stationary core and a sleeve positioned around the core that is rotatable relative to the core about an axis of rotation, the stationary core includes at least one permanent magnet having a plurality of circumferentially spaced magnetic poles, the plurality of circumferentially spaced magnetic poles includes a pickup pole that is positioned to magnetically attract developer mix in the reservoir to the outer surface of the sleeve for carrying by the sleeve as the sleeve rotates; a trim bar positioned in close proximity to the outer surface of the sleeve downstream from the pickup pole relative to an operative rotational direction of the sleeve to trim the developer mix on the outer surface of the sleeve prior to carrying the developer mix to a photoconductive drum of the image forming device; an auger positioned to convey developer mix in the reservoir toward the outer surface of the sleeve for pickup by the outer surface of the sleeve; a ledge on an inner surface of the housing extending axially with respect to the magnetic roll along a front of the reservoir, the ledge positioned upstream from the trim bar and downstream from the pickup pole with respect to the operative rotational direction of the sleeve, the ledge has a concave curved inner surface that is open to the reservoir and extends from a top front edge of the ledge positioned near the trim bar to a bottom rear edge of the ledge positioned near a front side of the auger.