Developing device and image forming apparatus using same

An image forming apparatus, comprising;

• at least a latent image carrier;
• charging means for charging a surface of the latent image carrier;
• latent image forming means for forming an electrostatic latent image on the latent image carrier;
• and
• developing means for developing the electrostatic latent image to form a toner image,
• wherein the developing means comprises:
• a developer carrier, which rotates while carrying a developer on a surface thereof, supplies a toner to a latent image on a surface of a latent image carrier at a section where the developer carrier faces the latent image carrier, and develops the latent image;
• developer replenishing means for replenishing the developer to the developing device;
• a supply conveyance path, which has a supply conveying member that conveys the developer in an axis line direction of the developer carrier while supplying the developer to the developer carrier;
• a circulation conveyance path, which has a circulation conveying member that conveys the developer reaching a downstream end in a conveyance direction of the supply conveyance path to an upstream end in the conveyance direction of the supply conveyance path;
• and
• developer discharge means for discharging part of the developer existing in the vicinity of the downstream end in the conveyance direction of the supply conveyance path, when the bulk of the developer existing in the vicinity of the downstream end in the conveyance direction of the supply conveyance path exceeds a predetermined height level.

A developing device, comprising:

• a developer carrier, which rotates while carrying a developer on a surface thereof, supplies a toner to a latent image on a surface of a latent image carrier at a section where the developer carrier faces the latent image carrier, and develops the latent image;
• developer replenishing means for replenishing the developer to the developing device;
• a supply conveyance path, which has a supply conveying member that conveys the developer in an axis line direction of the developer carrier while supplying the developer to the developer carrier;
• a circulation conveyance path, which has a circulation conveying member that conveys the developer reaching a downstream end in a conveyance direction of the supply conveyance path to an upstream end in the conveyance direction of the supply conveyance path;
• and
• developer conveyance amount regulating means for regulating the amount of the developer that passes through a developer discharge port for discharging part of the developer within the developer conveyance paths having the supply conveyance path and circulation conveyance path to the outside of the developer conveyance paths, and that through regulating positions within the developer conveyance paths,
• wherein the developer discharge port is disposed such that accumulated developer that is regulated by the developer conveyance amount regulating means is discharged from the developer discharge port when the amount of the accumulated developer exceeds a predetermined amount.