Patent ID: 7519312
Filing Date: 2009-04-14
Classification: G03G

Abstract:
1. A developing unit configured to supply toner to a photosensitive drum in an image forming device and is detachably mounted to a body of the image forming device, the developing unit comprising: a first developing roller that can be arranged in a position proximate to and parallel with the photosensitive drum in the interior of the image forming device body, and arranged in a position retracted from the photosensitive drum; a second developing roller that is arranged in a position proximate to the first developing roller and configured to supply toner to the first developing roller; and a roller contacting/retracting mechanism configured to move the first developing roller to a position proximate to the photosensitive drum in association with an operation that attaches the developing unit to the image forming device body, and move the first developing roller to a retracted position from the photosensitive drum in association with an operation that detaches the developing unit from the image forming device body, wherein the body of the image forming device comprises a mounting portion that is formed adjacent to the photosensitive drum to extend in the axial direction of the photosensitive drum, the mounting portion having a contact portion that is formed on the rear end in the axial direction, and the roller contacting/retracting mechanism including at least one arm member mounted thereon so as to rotate together with the second developing roller, a shaft member that is configured to extend and be movable in the axial direction, the shaft member comprising a first contact portion that can contact a contact portion of the image forming device body on a rear side end portion thereof in the axial direction, and configured to rotate the at least one arm member together with the second developing roller when moving in the axial direction, and at least one bearing member configured to support the rotation shafts of the first and second developing rollers.