Ricoh Company, Ltd.

Akemi Sugiyama

Hiroaki Matsuda

Hiroto Higuchi

Masanori Suzuki

Tsunemi Sugiyama

Hiroshi Nakai

Yasuaki Iwamoto

Fumihiro Sasaki

Kumi Hasegawa

Mitsuo Aoki

Shinichiro Yagi

Naohito Shimota

Kazuyuki Yazaki

An image formation method includes the steps of charging the surface of an electrophotographic photoconductor, exposing the charged photoconductor to a light image to form a latent electrostatic image on the photoconductor, developing the latent electrostatic image using a two-component developer containing a toner and a carrier to obtain a toner image, and transferring the toner image to an image receiving material directly or via an intermediate transfer member, with the photoconductor showing a surface friction coefficient of 0.40 or less, and the toner having toner particles with an average circularity of 0.930 or more.

Electrographic image formation method

A carrier for a two-component developer for developing a latent electrostatic image is composed of carrier particles, each of the carrier particles having a core particle and a coating layer provided on the surface of the core particle, with the coating layer containing an amino-group-containing modified silicone resin. A two-component developer is composed of a toner and the above-mentioned carrier.

Carrier for two-component developer for developing latent electrostatic images and developer using the carrier

A toner for developing electrostatic latent images contains a coloring agent, a release agent, a binder resin including a non-linear polyester resin with a hydroxyl number of 30 to 70 mgKOH/g, and a metallic compound of an aromatic oxycarboxylic acid with a central metal having a valence of 3 or more. The toner is used in combination with a carrier to prepare a two-component developer. The toner or two-component developer is held in a container. The present invention further provides an image forming apparatus equipped with the container that holds therein the above-mentioned toner or two-component developer.

Toner and two-component developer, container therefor, and image forming apparatus

Two-component developer, container filled with the two-component developer, and image formation apparatus

An electrophotographic image formation method for developing a latent electrostatic image formed on a latent image bearing member with toner to a toner image, using a two-component developer including a carrier and a toner. The zoner is held on a developer bearing member, with a gap between the facing surfaces of the latent image bearing member and the developer bearing member being set in a range of 0.1 mm to 0.5 mm. The carrier includes carrier particles, each carrier particle including a core material and a coating material which is coated on the surface of the core material The coating material includes a polysiloxane resin including at least an oxygen atom (O) and a silicon atom as constituent elements therefor, with an atomic ratio of the constituent elements, O/Si, being in a range of 2.1 to 4.0, and the carrier having a specific resistivity of 10 to 10 &OHgr;&middot;cm. A container holding therein the two-component developer, and an electrophotographic image formation apparatus with this container incorporated therein are disclosed.

ELECTROPHOTOGRAPHIC IMAGE FORMATION METHOD, CARRIER FOR TWO-COMPONENT DEVELOPER, TWO-COMPONENT DEVELOPER, CONTAINER HOLDING THEREIN THE TWO-COMPONENT DEVELOPER, AND ELECTROPHOTOGRAPHIC IMAGE FORMATION APPARATUS

An electrophotographic toner including at least a binder resin, a colorant, and a releasing agent, wherein the binder resin includes one or more components soluble in tetrahydrofuran, and wherein the one or more components has a molecular weight distribution such that at least one peak is present between 1,000 and 10,000, and the peak has a half width not greater than 15,000 when the molecular weight is measured by a gel permeation chromatography (GPC) method.

Electrophotographic toner and electrophotographic image forming method and apparatus using the toner

A two-component developer includes a toner containing toner particles with a volume diameter of 8 &mgr;m or less, and a carrier containing carrier particles, each carrier particle including at least one core particle and a carrier core coating layer, the carrier core coating layer being made of a silicone resin and a silicone oil, the carrier having a fluidity of 45 seconds or less.

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Shizuoka, Japan

Akemi Sugiyama