Patent ID: 9268261
Filing Date: 2016-02-23
CPC Classification: G03G

Claim Text:
1. A developing device comprising: a frame; a developing roller rotatable about an axis that defines an axial direction, and having a peripheral surface on which a layer of developing agent is configured to be formed, the developing roller having axial end portions; a blade unit extending in the axial direction and in contact with the peripheral surface of the developing roller, the blade unit being configured to regulate a thickness of the layer of the developing agent on the peripheral surface of the developing roller, the blade unit having end portions in the axial direction; a first seal member configured to seal a boundary between the frame and the axial end portions, the first seal member having an inner edge in the axial direction; and a second seal member extending in the axial direction and configured to seal a boundary between the frame and the blade unit, wherein the frame comprises a fixing portion to which the end portions of the blade unit are fixed, the fixing portion having a support surface facing the developing roller, the support surface having a boss formed with a thread hole into which a screw for fixing the blade unit to the fixing portion is inserted, and the support surface having an outer edge and an inner edge in the axial direction, the outer edge of the support surface being positioned outward of the inner edge of the first seal member in the axial direction, and the inner edge of the support surface and at least a part of the boss being positioned inward of the inner edge of the first seal member in the axial direction, wherein the blade unit comprises: wherein the frame has an attachment surface to which the second seal member is attached, the attachment surface being positioned inward of the support surface in the axial direction, the support surface protruding closer to the developing roller than the attachment surface is to the developing roller, and wherein the inner edge of the support surface is positioned between the boss and the first seal member in a direction perpendicular to the axial direction and in parallel to the support surface, the inner edge of the support surface contacting the blade support section.