Ricoh Company, Ltd.

Natsumi Katoh

Junichi Matsumoto

Nobuo Iwata

Tomoyuki Ichikawa

Tomoya Ohmura

Hiroshi Kikuchi

Yasuo Takuma

A development device includes a developing section to visualize a latent image formed on a latent image carrier with developer including toner and carrier. The development device has a developer supply opening and a developer collection opening, a circulation unit to transport the developer collected from the developer collection opening of the developing section to the developer supply opening of the developing section and including a developer container to store the developer collected from the developing section disposed upstream from the development section in a direction in which the developer is circulated, and a developer cooler to cool the developer contained in the developer container.

Development device and image forming apparatus

The development device includes a development member and a circulation member. The development member develops an electrostatic latent image formed on a latent image carrier with a developer including toner and a carrier to make the electrostatic latent image visible. The circulation member receives the developer discharged from the development member and conveys the developer back to the development member. The circulation member includes a container provided upstream from the development member in a conveyance direction of the developer to store the developer. The container includes an agitator provided inside the container and agitates and mixes the developer and fresh toner supplied to the container. The agitator includes a rotatable agitation member in which one or more holes are formed through which the developer passes to mix the fresh toner and the developer to be agitated in the container.

A developing apparatus for an image forming apparatus. In order to suppress toner scattering that may occur after a development operation has been halted for a long time, the developer is transferred to a developer storage unit on the exterior of the developing machine when the development operation ends. A range in which an angle of a restricting member upstream side central angle &#x3b1;, which is a central angle of the surface of a developing roller on the upstream side of a restricting member opposing position opposing a developer amount restricting member in a surface motion direction of the developing roller, is not less than 0&#xb0; and not more than 60&#xb0; is set as a low magnetic flux density area &#x3b3; in which the maximum value of a normal direction magnetic flux density on the surface of the developing roller is not more than 30 mT.

Developing apparatus and image forming apparatus using same

A developing device includes a developing unit, a developer agitating unit, a developer conveying unit, and a toner supplementing unit. The developing unit develops an electrostatic latent image on an image carrier with a developer containing toner and carrier. The developer agitating unit agitates the developer. The developer conveying unit connects the developing unit and the developer agitating unit, and conveys the developer from the developing unit to the developer agitating unit. The toner supplementing unit is connected to the developer conveying unit, and supplements toner to the developer conveyed from the developing unit to the developer agitating unit.

Developing device and image forming apparatus

An image forming apparatus and method for developing a latent image on an image bearing member includes the image bearing member, an air flow generator, and an air intake device. The image bearing member is configured to bear the latent image on the surface thereof. The airflow generator is configured to generate airflow to transport a developer. The air intake device is configured to connect outside the image forming apparatus with the airflow generator to draw air from outside the image forming apparatus to supply the air to the airflow generator.

Image forming apparatus and image forming method including transporting developer using an airflow generator

A developing apparatus using a two-component developer constituted by a magnetic carrier and a toner, and an image forming apparatus comprising the developing apparatus. A developing unit and a stirring unit are provided, and in order to suppress toner scattering that may occur after a development operation has been halted for a long time, and thereby suppress contamination of the apparatus interior, the developer in a developing machine is transferred to a stirrer serving as a developer storage unit on the exterior of the developing machine when the development operation ends. Further, to extend the life of the developer, a range in which an angle of a restricting member upstream side central angle &#x3b1;, which is a central angle of the surface of a developing roller serving as a developer carrier on the upstream side of a restricting member opposing position opposing a doctor blade serving as a developer amount restricting member in a surface motion direction of the developing roller, is not less than 0[&#xb0;] and not more than 60[&#xb0;] is set as a low magnetic flux density area &#x3b3; in which the maximum value of a normal direction magnetic flux density on the surface of the developing roller is not more than 30 [mT].

A development agent circulation unit includes a development unit, an agitation unit, and a rotary feeder. The development unit develops a latent image on an image carrier using a developing agent. The agitation unit agitates developing agent recovered from the development unit. The rotary feeder receives the developing agent from the agitation unit and discharges the developing agent in predetermined discrete amounts. The discharged developing agent is transported to the development unit using a gas stream. The rotary feeder includes a rotor and a stator having a clearance 't' between the rotor and the stator. The clearance 't' satisfies a relation &#x201c;t&#x3c;2D&#x201d; where D denotes a developing agent particle diameter, and a toner particle diameter dt of a toner particle of the developing agent and a carrier particle diameter dc of a carrier particle of the developing agent satisfy a relation D=dc+2dt.

Developing agent circulation system and image forming apparatus using same

A developing system includes a developing unit, a mixing container, a rotary feeder, an air pump, and an airflow regulator. The developing unit is configured to convert a latent image into visible form using a developer. The mixing container is separated from the developing unit and is configured to hold and mix part of the developer after use. The rotary feeder is configured to dispense the developer from the mixing container to a delivery path. The air pump is configured to supply compressed air to deliver the dispensed developer to the developing unit through the delivery path. The airflow regulator is located where the rotary feeder connects to the delivery path, and is configured to prevent the compressed air from flowing toward the rotary feeder from the delivery path.

Developing system and image forming apparatus incorporating same

A development device includes a developer carrier, and a developer conveyance path. The developer carrier carries and conveys developer having a magnetic property. The developer carrier includes a plurality of magnetic poles provided inside the development carrier. The developer conveyance path is provided above the developer carrier and conveys the developer by a flow of air such that the developer is conveyed parallel to the developer carrier. The developer conveyance path is provided with a first developer outlet disposed above the developer carrier and open along a direction of conveyance of the developer to discharge the developer to the outside of the developer conveyance path to directly supply the developer to the developer carrier.

A developing device including a developing unit configured to develop an electrostatic latent image formed on a latent image bearing member with a developer comprising a toner and a carrier, and a circulation unit configured to collect the developer from the developing unit and return the developer to the developing unit. The circulation unit includes a container including a main body having an inverted cone shape, a supply opening provided in a top thereof, and a discharge opening provided in a bottom thereof, configured to hold a part of the developer and provided on an upstream side from the developing unit relative to a direction of circulation of the developer. The container includes a plurality of agitation members configured to agitate the developer collected from the developing unit and fresh toner so that a plurality of flows of the developer is produced in the container.

Developing device including a stirring mechanism for a two-component developer and image forming apparatus including same

A developing device that efficiently adjusts the amount of charge on the developing agent without being affected by external conditions, and that continuously supplies a developing agent with the appropriate toner concentration and amount of charge. An ionized air flow adjusts the amount of charge on the developing agent discharged from the developing unit to improve the dispersability of the replenished toner without applying unnecessary stress. The developing agent is raised upwards by a screw, downwards by an agitation member, and then gathered by a screw in a circulating flow. Consequently, the developing agent is uniformly mixed within the developing agent agitation unit. This circulating flow of the developing agent increases the probability of contact and reduces damage to the developing agent. When the ionized air flow reduces the amount of charge before agitation, the toner can be uniformly charged to the appropriate value.

Developing device using two-component developing agent and image forming apparatus provided with same

A developing device including a development part for developing latent images to toner images. The developing device also includes an agitation part that agitates developer, and a controller, which controls an agitation strength of an agitator in the agitation part. The developer circulates between the development part and the agitation part.

Developing device for developing latent images to toner images

An image forming apparatus includes a development device for supplying a developer containing toner and carrier to an electrostatic latent image carrying member for carrying thereon an electrostatic latent image, or a process cartridge for integrally storing the development device and the electrostatic latent image carrying member. The development device includes a conveyance path for charging and conveying the developer, and a developer carrying member for developing the electrostatic latent image into a toner image with the use of the developer conveyed through the conveyance path. The conveyance path includes a first conveyance member for receiving replenished toner and generating conveyance force for conveying the replenished toner and the developer in one direction, and a second conveyance member for generating conveyance force for conveying a portion of the developer conveyed by the first conveyance member in the opposite direction to the conveyance direction of the first conveyance member.

Growing community of inventors

Atsugi, Japan

Natsumi Katoh