Development unit, process cartridge and image forming apparatus using same

An image forming apparatus, comprising:

• a latent image carrier configured to carry a latent image;
• and
• a development unit configured to develop the latent image carrier, the development unit comprising:
• a toner carrying device facing the latent image carrier and configured to have a first electrode and a second electrode arrayed with a given interval, the first electrode and the second electrode being supplied with a given voltage to set an electric field changing in a given time cycle between the first electrode and the second electrode, the electric field being used to hop toner particles on or over the toner carrying device to form a toner cloud for developing a latent image formed on the latent image carrier;
• a regulating member configured to regulate an amount of toner on the toner carrying device;
• and
• a toner leak protection member made from a conductive material and configured to prevent leakage of toner particles from the development unit, the toner leak protection member being disposed at a downstream side of the regulating member with respect to a direction of surface movement of the toner carrying device, the toner leak protection member being supplied with a bias voltage.

A process cartridge detachably mountable in an image forming apparatus employing electrophotography and having a latent image carrier for carrying a latent image, a charger, and a cleaning unit, comprising:

• a development unit, being integrated with at least any one of the latent image carrier, the charger, and the cleaning unit, configured to develop the latent image carrier, the development unit, comprising:
• a toner carrying device facing the latent image carrier and configured to have a first electrode and a second electrode arrayed with a given interval, the first electrode and the second electrode being supplied with a given voltage to set an electric field changing in a given time cycle between the first electrode and the second electrode, the electric field being used to hop toner particles on or over the toner carrying device to form a toner cloud for developing a latent image formed on the latent image carrier;
• a regulating member configured to regulate an amount of toner on the toner carrying device;
• and
• a toner leak protection member made from a conductive material and configured to prevent leakage of toner particles from the development unit, the toner leak protection member being disposed at a downstream side of the regulating member with respect to a direction of surface movement of the toner carrying device, the toner leak protection member being supplied with a bias voltage.