Developing unit

A developing unit comprising:

• a conveying shaft provided within the developing unit and rotates;
• a developing conveying portion that is spiral-shaped, formed at an outer periphery of the conveying shaft, and conveys the developer in an axial direction as the conveying shaft rotates;
• a discharge opening formed in an inner wall surface that opposes the conveying shaft, and discharging the developer from the inner wall surface;
• an accumulating chamber accumulating the developer discharged from the discharge opening;
• and
• an opening/closing member that is plate-shaped, and opens and closes the discharge opening due to its own weight as the rotating body rotates, and is in an open state at the developing position,
• a flow regulating portion, whose cross-section narrows in a direction opposing a conveying direction, being formed at a surface of an upstream side end portion of the opening/closing member in the conveying direction, the surface being opposite to the discharge opening,
• the developing unit being held at a rotating body, and successively being made to oppose a developing position of an image carrier due to rotation of the rotating body.

A developing unit comprising:

• a conveying shaft means provided within the developing unit and rotates;
• a developing conveying means for conveying a developer in an axial direction as the conveying shaft rotates, the developing conveying means being spiral-shaped, and formed at an outer periphery of the conveying shaft, and;
• a discharge opening means for discharging the developer from the inner wall surface, the discharge opening means being provided in an inner wall surface which opposes the conveying shaft, and;
• an accumulating chamber means for accumulating the developer discharged from the discharge opening;
• and
• an opening/closing means for opening and closing the discharge opening due to its own weight as the rotating body rotates, the opening/closing means being plate-shaped, and being in an open state at the developing position,
• the developing unit being held at a rotating body, and successively being made to oppose a developing position of an image carrier due to rotation of the rotating body,
• the opening/closing means having an opening/closing fulcrum at a lower end portion of the opening/closing means at the developing position.