Ricoh Company, Ltd.

Kazuyuki Sugihara

Tomoji Ishikawa

Katsuhiro Kosuge

Yoshiyuki Kimura

Kenji Maeda

Shinji Kato

Takayuki Maruta

Hideki Kimura

Kazuhisa Sudo

Katsumi Masuda

Kiyotaka Sakai

Hiroyuki Nagashima

Tsuyoshi Imamura

Chikara Imai

Nobuyuki Koinuma

Fumio Ogata

Yoshihide Kawamura

Yuji Sawai

Hiroshi Takashima

Yoshio Takamiya

Hideo Yoshizawa

Satoshi Hatori

Nobuo Takami

Noboru Sawayama

Junichi Terai

Takuzi Yoneda

Kazuo Nojima

Takuji Yoneda

Tetsuro Miura

Katsuji Watabe

Kaoru Yoshimatsu

An image forming apparatus includes an image forming mechanism and an image bearing member. The image forming mechanism is configured to form an image. The image bearing mechanism is detachably provided to the image forming apparatus. The image bearing mechanism includes an image bearing member configured to bear the image formed by the image forming mechanism, and a through shaft configured to support the image bearing member.

Image forming apparatus having a detachable cartridge including a photoconductive drum with axis shaft having a minimal rotational eccentricity, and a method of assembling the image forming apparatus

An image forming apparatus whereby it is possible to prevent unevenness in developing density caused by misalignment between the central axes of a driven side rotational coupling section for rotating a developer carrier and a drive side rotational coupling section for transmitting rotational drive force to the driven side rotational coupling section. The driven side rotational coupling section is fixed and the position thereof can be corrected slightly, by engaging the driven side rotational coupling section with a drive side rotational coupling section. A transmission gear is provided which meshes with the driven side rotational coupling section and transmits rotational drive force used to move the surface of the developer carrier. By means of an axle provided on at least one end of the transmission gear engaging with a positioning member on the main body of the image forming apparatus, the developer carrier is positioned in the main body of the image forming apparatus.

Image forming apparatus

A developing device includes a developer carrier and a developer regulating member including a developer regulating part opposing a surface of the developer carrier to regulate the developer carried and conveyed by the developer carrier. The developer regulating member is formed from a single metallic member and includes a space that faces an inner surface of the metallic member. The space extends in a direction perpendicular to a moving direction of the surface of the developer carrier. The developing device can include a cooling device that cools the developer regulating member from an inner surface side of the metallic member facing the space.

Developer regulating member, developing device, electrophotographic image forming process cartridge, and image forming apparatus including the developer regulating member

A developing device of the present invention includes a developing roller including a sleeve and a magnet roller accommodated in the sleeve. The surface of the sleeve s configured such that the center portion, including an image forming range corresponding to the image forming range of an image carrier, in the direction of width perpendicular to the direction of movement of the above has a higher developer conveying ability than opposite end portions outward of the center portion. Opposite ends of the magnetic pole of the magnet roller in the direction of width face the opposite end portions of the sleeve.

Developing device using a developer carrier formed with grooves and image forming apparatus including the same

Developing device and method for performing effective charging and mixing of developer and image forming apparatus using the developing device

A developing device for an image forming apparatus of the present invention includes a developing roller made up of a sleeve and a magnet roller and a doctor facing the surface of the sleeve. The edge of the doctor faces the sleeve at a particular position selected to stabilize the amount of a developer to be scooped up, protect the developer from deterioration, and allow an adequate amount of charge to deposit on the developer by friction.

Developing device and image forming apparatus using the same

An image forming apparatus includes a development mechanism using a two-component development agent and which includes a development roller and first and second transfer screws. The first transfer screw, arranged at a position approximately horizontal and in parallel to the development roller, includes a first number of screw spirals for transferring the development agent from a first end to a second end of the first transfer screw and conveying the development agent to the development roller. The second transfer screw, arranged approximately horizontal and in parallel to the first transfer screw, includes a second number of screw spirals for transferring the development agent from a first end to a second end of the second transfer screw and conveying the development agent from the second end of the second transfer screw to the first end of the first transfer screw. The first and second numbers of the screw spirals are different from each other.

Method and apparatus for image forming capable of performing an effective mixing of development agent

A developer container for use in an image forming apparatus including a supporting member rotating around a rotation shaft thereof. A plurality of developing devices are arranged on the supporting member, each developing device including a developer supplying device. A plurality of cylindrically-shaped developer containers containing developer are provided, each developer container having an opening and a guide, and each developer container being detachably mounted on the developer supplying device. A container rotating device rotates the developer container, in which the guide is arranged that when one of the developing devices needs to be filled with the developer, the container rotating device rotates the developer container to transfer the developer in the developer container to the opening in accordance with a rotating movement of the developer container.

Image forming apparatus having an improved developer-supplying mechanism and method thereof

An image forming apparatus of the present invention includes a revolver type developing unit rotatably mounted on an apparatus body and having a plurality of developing sections, and an intermediate image transfer body having an endless movable surface to which a toner image is transferred from an image carrier. While the intermediate image transfer body is caused to run idle, the apparatus allows a minimum of toner apt to contaminate the background of a recording medium to be transferred from the developing section located at a developing position to the image carrier. Particularly, the apparatus frees the recording medium from contamination in the form of a band extending in the widthwise direction of the medium.

Image forming apparatus with control over developing unit during an idle running of an intermediate image transfer body

An image forming apparatus including a development unit rotatably supported by a body of the apparatus and including a plurality of developing subunits and a plurality of replaceable developer containers each storing a developer to be replenished to a particular one of the developing subunits. Also included is a stepping motor configured to cause the developing unit to rotate in order to bring any one of the developing subunits to a developing position, a preventing mechanism configured to prevent the developing unit from rotating at a time of replacement of any one of the developer containers due to an unexpected change in a voltage or a current driving the stepping motor, and a locking portion included in either one of the developing unit and the body and an engaging portion included in the other of the developing unit and the body, in which the locking portion and the engaging portion selectively engaging with each other for preventing the developing unit from rotating. Further included is a door member opened when any one of the developer containers is to be removed from the apparatus or closed when development is under way. The locking portion and the engaging portion engaging with each other in mechanically interlocked relation to an opening movement of the door member. Also included is a moving device configured to cause the locking portion to engage with the engaging portion by mechanically interlocking the opening movement of the door member to a movement of the locking portion.

Image forming apparatus including a preventing mechanism for preventing

An image forming apparatus including a supporting member rotating around a rotation shaft thereof. A plurality of developing devices are arranged on the supporting member, each developing device including a developer supplying device. A plurality of cylindrically-shaped developer containers containing developer are provided, each developer container having an opening and a guide, and each developer container being detachably mounted on the developer supplying device. A container rotating device rotates the developer container, in which the guide is arranged that when one of the developing devices needs to be filled with the developer, the container rotating device rotates the developer container to transfer the developer in the developer container to the opening in accordance with a rotation movement of the developer container.

Image forming apparatus having an improved developer-supplying mechanism

A color image forming apparatus having a revolving type developing unit detachably installed therein. The revolving type developing unit includes a plurality of different color developing devices each having a developing roller therein. Each of the developing rollers is movably mounted on the developing device so that a gap between each of the developing rollers and a periphery of a photoconductive drum which is to be formed when the revolving type developing unit is set in the color image forming apparatus is enabled to be adjusted.

PC drum integrated revolving type developing unit with pull-out supporter

An image forming apparatus includes an image bearing member, a developing device to develop a latent image on a surface of the image bearing member, a developer bearing member including a magnet therein, which bears developer on a surface thereof by a magnetic force of the magnet and carries the developer towards a developing position facing the image bearing member by being rotated, a limiting member that is placed facing the developer bearing member so as to limit a thickness of a layer of the developer borne on the developer bearing member, and a developing device casing. The limiting member is provided with a magnetizable member having a protruding portion protruding toward the developer bearing member at a part that does not face the magnet and a recessed part at a part that faces the magnet, in which the magnetizable member is disposed upstream of the limiting member in a developer conveying direction of the developer bearing member and is placed such that the protruding portions are nearer to the surface of the developing roller than the limiting member and the recessed part is more distant from the surface of the developing roller than the limiting member. The limiting member is made of a non-magnetizable material.

Image forming apparatus having improved developer limiting member

A rotary developing device includes a developing unit having a plurality of developing chambers arranged around an axis of rotation of the developing unit and each having a developer agitating mechanism thereinside wherein the rotary developing device is rotatable about the axis to locate any one of the plurality of developing chambers at a developing position where an image carrier is located. The device includes a drive inputting device located in proximity with the axis of the rotation for inputting a driving force to the agitating mechanism of one of the plurality of developing chambers which is located at the developing position. A drive transmitting mechanism is provided which transmits at a developing units side, a driving force to at least one of the plurality of developing chambers not located at the developing position.

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Yokohama, Japan

Kazuyuki Sugihara