Abstract: A developing device of the present invention uses 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 &mgr;m to 8.0 &mgr;m while the toner grains having grain sizes of 5 &mgr;m and below occupy 40 number % to 80 number % 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, image reproducibility.

Abstract: 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.

Abstract: A toner including at least a binder resin; a colorant; a charge controlling agent; and a wax (B), in which the charge controlling agent comprises a compound selected from the group consisting of: an aromatic oxycarboxylic acids, derivatives of aromatic oxycarboxylic acid, salts of aromatic oxycarboxylic acids and salts of derivatives of aromatic oxycarboxylic acids; and a zirconium compound (A), and in which the zirconium compound (A) and the wax (B) have a weight ratio (A/B) satisfying the following relationship:

Abstract: A two component developer comprising a magnetic toner containing a binder resin and a magnetic particle, and a magnetic carrier containing a magnetic particle, wherein the magnetic toner has an average particle diameter of 4.0 to 10.0 &mgr;m, and contains 5 to 80 No. % of toner particles having particle diameter of 5 &mgr;m or less, and exhibits magnetization of 10 to 25 emu/g under magnetic field of 5 kiloersteds.

Abstract: A two-component developer comprises a toner which contains at least a resin and a colorant and to which an external additive is added, and a carrier. The toner has a number average molecular weight (Mn) not greater than 3,000 and contains particles having a molecular weight not greater than 1,000 in an amount not less than 40 number %. The carrier satisfies the relation 3,000,000≦&sgr;1000×Dc3≦20,000,00  (1) where &sgr;1000 represents a magnetization (emu/g) of the carrier at 1,000 oersted, and Dc represents a volume average particle diameter (&mgr;m) of the carrier.

Abstract: 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 109 to 1016 &OHgr;·cm.

Abstract: An image forming apparatus including a photoconductor, and a developing unit having a developing sleeve for carrying a developer and a developer regulating plate for regulating the amount of the developer carried on the sleeve, wherein the developer is composed of a carrier and a toner, wherein that portion of the toner which has a particle diameter of 2.0-4.0 &mgr;m accounts for 30-70% of a total number thereof, and wherein the developer regulating plate is grounded so that when the developing sleeve is applied with a bias voltage, an electric field is formed between the developer regulating plate and the developing sleeve, whereby toner deposits on the developing sleeve are transferred to the developer regulating plate.

Abstract: An image forming method and apparatus, wherein a surface of a photoconductor is charged with a contact-type charging roller having a surface roughness of 2-40 &mgr;m, and exposed imagewise to form an electrostatic latent image thereon, the latent image being developed with a toner, transferred to a transfer member and fixed, and wherein the toner comprises a colorant, and a binder resin containing a tetrahydrofuran-soluble component having such a molecular weight distribution that at least one peak having a half width not greater than 15,000 is present between 1,000 and 10,000 when measured by gel permeation chromatography.

Abstract: A two-component developer consists of a toner, which contains at least a resin and a colorant and to which an external additive is added, and a carrier. This two-component developer has the toner that has a number average molecular weight (Mn) of 3,000 or less and contains particles having a molecular weight of 1,000 or less at 40 number % or more, and also has the carrier that satisfies general formula (1) as follows: 3,000,000≦&sgr;1000×Dc3≦20,000,000  (1) where &sgr;1000 represents a magnetization (emu/g) of a carrier at 1,000 oersted, and Dc represents volume average particle diameter (&mgr;m) of the carrier.

Abstract: An image forming toner is provided, including at least:

Abstract: A two-component developer including at least a magnetic toner and a magnetic carrier having magnetic particles coated with carbon black. The magnetic toner adheres to the magnetic carrier due to the magnetic interaction.

Abstract: A toner including toner particles including a binder resin and a release agent, wherein when the toner is molded into a plate upon application of a pressure of 478 kg/cm2, the toner plate has a surface having a coefficient of static friction of from 0.20 to 0.40. An image forming apparatus including an image bearing member, an image developer to form a toner image on the image bearing member, an image transferer configured to transfer the toner image on a receiving material and a fixer configured to fix the toner image thereon, wherein the apparatus has a waiting time not longer than 15 seconds, and a maximum power consumption not greater than 1.5 KW and 30 W in an image forming state and in a standby state, respectively, wherein the toner is the toner mentioned above.

Abstract: 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.

Abstract: A two-component developer consists of a toner, which contains at least a resin and a colorant and to which an external additive is added, and a carrier.

Abstract: 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.

Abstract: 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.

Abstract: 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.