Ricoh Company, Ltd.

Junichi Sano

Takeyoshi Sekine

Toshio Koike

Masayuki Yamane

Hiroto Higuchi

Kunihiro Ohyama

Fumihiro Sasaki

Atsushi Sampe

Maiko Kondo

Tokuya Ohjimi

A two-component developing apparatus includes a developer carrier, a first regulating member, a developer container, and a toner container. The developer carrier is configured to carry and transfer the two-component developer including a magnetic carrier. The first regulating member is configured to regulate an amount of the two-component developer carried and transferred by the developer carrier. The developer container is configured to receive the developer removed by the first, regulating member. The toner container is configured to supply toner to the developer carrier. The developer stirring member is configured to carry and stir the developer between the first regulating member and the second regulating member. The second regulating member includes a support member on one end side of the second regulating member in its longitudinal direction to which greater amount of the developer is supplied than to another end side of the second regulating member.

Two component development apparatus and process cartridge

A developing device including a developer containing magnetic toner grains and includes a main pole for development disposed in a sleeve. Flux density generated by the magnetic pole in a direction normal to the surface of the sleeve outside of the surface has an attenuation ratio of 50% or above. The toner grains have a weight mean grain size of 6.0 &#x3bc;m to 8.0 &#x3bc;m while the toner grains having grain sizes of 5 &#x3bc;m and below occupy 40% to 80% of the entire developer. The toner grains have magnetization strength of 10 emu/g to 25 emu/g in a magnetic field of 5 kOe or magnetization strength of 7 emu/g to 20 emu/g in a magnetic field of 1 kOe. The toner grains reduce toner scattering and image defects despite that they are magnetic, thereby implementing ultrahigh resolution.

Developing device using a two-ingredient type developer and image forming apparatus including the same

A developing device developing a latent image on a latent image carrier with a developer, and including a casing having an opening facing the latent image carrier and a developer carrier. Also included is a magnetic field generating device including a first magnetic pole generating a magnetic field causing the developer to rise on the developer carrier in a form of a magnet brush in a developing region, and a second magnetic pole generating a magnetic field at a downstream side of the first magnetic pole in a rotating direction of the developer carrier. Further, a toner-scattering restraining device is provided on an end portion of the casing at the downstream side of the developing region, and a magnetic member provided on a side of the toner-scattering restraining device facing the latent image carrier. A peak of a magnetic flux density set by the second magnetic pole in its normal direction is located outside of the opening.

Developing device including magnetic member provided on toner-scattering restraining device and image forming apparatus including the developing device

A charger includes a charging member for charging a desired member. The charging member is made up of a conductive support and a film formed on the support and formed of a substance having negative electron affinity. The film affects electrostatic electron discharge at a low voltage and can therefore charge the desired member more efficiently than a substance having electron affinity. In addition, the charger does not affect discharge and therefore reduces ozone.

Growing community of inventors

Tokyo, Japan

Junichi Sano