Abstract: A developing cartridge may include: a casing configured to accommodate developer therein, the casing extending in the first direction; a coupling rotatable about a first axis extending in the first direction, the coupling being positioned at one side of the casing in the first direction; a detection gear rotatable about a second axis extending in the first direction, the detection gear being positioned at another side of the casing in the first direction; and a storage medium including an electric contact surface, the electric contact surface being positioned at the one side of the casing in the first direction.

Abstract: The present invention provides a magnetic carrier that can stably impart charge to a toner on a long term basis and that exhibits an excellent toner separation property and thus exhibits an excellent developing performance. This magnetic carrier is a magnetic carrier in which a vinyl resin coats the surface of a resin-filled core in which a resin is filled in pores of a porous ferrite particle, wherein the resistivity, Mg content, and total content of Sr and Ca oxides of the porous ferrite particle exhibit prescribed values and the magnetic carrier has a total area—in the backscattered electron projection image obtained by observation using a scanning electron microscope at an acceleration voltage of 2.0 kV—for a region originating with the porous ferrite particle of from at least 0.2 area % to not more than 5.0 area % with reference to the projected area of the magnetic carrier.

Abstract: The developing method includes developing an electrostatic latent image on an image bearing member with a two-component developer including a toner and a carrier and born on at least one developer bearing member, whose surface moves at a linear speed of from 300 mm/sec to 2,000 mm/sec. The carrier includes a particulate core material; and a cover layer located on a surface of the core material and including a crosslinked material obtained by crosslinking a resin including a first unit having a specific tris(trialkylsiloxy) silyl group and a second unit having a specific alkoxysilyl group having a crosslinking ability. Each of the first unit and the second unit is included in the resin in a molar ratio of from 0.1 to 0.9 based on all the units included in the resin.

Abstract: A developer, including a toner including a binder resin comprising a crystalline resin; and a colorant, and a resin carrier comprising a resin; a magnetic particulate material having a magnetic anisotropy, dispersed in the resin, and having a saturated magnetization of from 16 to 30 emu/g, a coercive force of from 15 to 40 kA/m and an average particle diameter not less than 15 ?m and less than 100 ?m.

Abstract: An image forming method using a two component developing system is provided in which a print speed is not less than 300 mm/s, a peak-to-peak voltage of an AC component in a developing bias is not more than 1.3 kV, a sufficient image density can be ensured, and a recorded image having a small amount of magnetic carrier remaining on the image and having high image quality can be obtained. A magnetic carrier that forms a two component developer contains a magnetic core and a resin. The magnetic core is a ferrite containing Sr and Ca inside thereof at the same time, having a small crystal grain diameter, a high density crystal-grain boundary structure, and an extremely large capacitance of the grain boundary. Use of the ferrite can provide the above method.

Abstract: An object of the present invention is to provide a carrier containing core material particles having magnetism and a coating layer on the surfaces of the core material particles, wherein the core material particles have a magnetization at a magnetic field of 1,000 Oersted of 40 emu/g to 100 emu/g, and the carrier has a weight average particle diameter of 20 ?m to 45 ?m, a resistance (Log R) of 11 ?·cm to 17 ?·cm and a relaxation time ? of 150 seconds to 800 seconds.

Abstract: A contact developing method including supplying a two-component developer to an electrostatic latent image on a rotating image bearing member by rotating a developing sleeve and a rotatable magnet having multiple magnetic poles provided inside the developing sleeve, to develop the electrostatic latent image into a toner image. The developing sleeve and the image bearing member rotate in the same direction while facing each other. The two-component developer comprises a non-magnetic toner and a carrier. The carrier comprises a magnetic core particle and a resin layer covering the magnetic core particle. The resin layer comprises a conductive particle and a resin. The conductive particle comprises an alumina-based material and a conductive layer covering the alumina-based material. The resin is obtained by heating a copolymer comprising a monomer A unit and a monomer B unit.

Abstract: An image forming method using a two component developing system is provided in which a print speed is not less than 300 mm/s, a peak-to-peak voltage of an AC component in a developing bias is not more than 1.3 kV, a sufficient image density can be ensured, and a recorded image having a small amount of magnetic carrier remains on the image and having high image quality can be obtained. A magnetic carrier that forms a two component developer contains a magnetic core and a resin. The magnetic core is a ferrite containing Sr and Ca inside thereof at the same time, having a small crystal grain diameter, a high density crystal-grain boundary structure, and an extremely large capacitance of the grain boundary. Use of the ferrite can provide the above method.

Abstract: A carrier for developing an electrostatic latent image which includes a core material and a resin coating layer provided on the core material. The resin coating layer includes a resin and a particulate tin oxide, and the surface of the particulate tin oxide is coated with carbon.

Abstract: A two-component developer containing a yellow toner and a magnetic carrier, wherein the yellow toner has the characteristics: (i) when the concentration of the yellow toner in a solution of the yellow toner in chloroform is represented by Cy (mg/ml) and the absorbance of the solution at a wavelength of 422 nm is represented by A422, a relationship between Cy and A422 satisfies the relationship of 6.00<A422/Cy<14.40; (ii) the lightness L* and chroma C* of the yellow toner determined in a powder state satisfy the relationships of 85.0?L*?95.0 and 100.0?C*?115.0; and (iii) the absolute value for the triboelectric charge quantity of the yellow toner measured by a two-component method using the yellow toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.

Abstract: The purpose is to provide, in a development apparatus using a two-component developer, a compact development apparatus, image forming apparatus and development method that prevents carrier deterioration and that can carry out good image formation over a long time period. In a development apparatus using a developer in which are mixed a toner, a carrier, and opposite polarity particles that are charged to a polarity opposite to the charging polarity of the toner, the surface charge density of the opposite polarity particles should be in the range of 0.5 to 3.0 times the surface charge density of the carrier.

Abstract: A developing device uses a two-component developer including at least carriers and toners. The toners are supplied to an image bearing member bearing an electrostatic latent image so that a toner image is developed from the electrostatic latent image. The developing device has a developing roller arranged to oppose the image bearing member; and a magnetic roller arranged to oppose the developing roller. The magnetic roller retains the two-component developer to supply toners to the developing roller. The developing roller and the magnetic roller are rotationally driven in directions to be opposite from one another at an opposed position, and a magnetic pole of the magnetic roller and a magnetic pole of the developing roller have magnetic polarities different from one another at the opposed position. A surface roughness of the magnetic roller is greater than a surface roughness of the developing roller.

Abstract: A two-component developer containing a magenta toner and a magnetic carrier, wherein the magenta toner has the characteristics: (i) when the concentration of the magenta toner in a solution of the magenta toner in chloroform is represented by Cm (mg/ml) and the absorbance of the solution at a wavelength of 538 nm is represented by A538, a relationship between Cm and A538 satisfies the relationship of 2.00<A538/Cm<6.55; (ii) the lightness L* and chroma C* of the magenta toner determined in a powder state satisfy the relationships of 35?L*?45 and 60?C*?72; and (iii) the absolute value for the triboelectric charge quantity of the magenta toner measured by a two-component method using the magenta toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.

Abstract: A carrier contains a core; and a cover layer located overlying the core, wherein the cover layer comprises a binder resin, a first particulate material and a second particulate material, wherein the following relationships are satisfied: 1<(D1/h)<10, and 0.001<(D2/h)<1, wherein D1(?m) represents a volume average particle diameter of the first particulate material, D2(?m) represents a volume average particle diameter of the second particulate material, and h (?m) represents a thickness of the cover layer, and wherein the second particulate material has a volume resistivity of not greater than 1.0×1012 ?·cm.

Abstract: In a carrier comprising carrier particles; each carrier particle comprising a carrier core and a coat layer for coating the carrier core, the carrier core has a ferrite component containing i) a metal oxide having at least one of metallic elements Mg, Li and Ca, the total-sum content of which is 10 to 40 mole % based on the whole ferrite component, and ii) a metal oxide having at least one of metallic elements Mn, Cu, Cr and Zn, the total-sum content of which is 50 to 4,000 ppm based on the whole ferrite component. The carrier has a volume distribution based 50% particle diameter (D50) of from 15.0 to 55.0 ?m and a degree of surface unevenness of from 1.05 to 1.30, and the coat layer contains particles; the particles having a number-average primary particle diameter of from 10 to 500 nm.

Abstract: A carrier containing a core material and a resin coating layer located overlying the surface of the core material. The resin coating layer contains resin and electroconductive particles having an oil absorption amount of from 10 to 300 ml/100 g. The electroconductive particle contains a base material particle and an electroconductive coating layer located overlying the surface of the base material particle. The electroconductive coating layer contains an underlayer containing tin dioxide and an upper layer containing indium oxide and tin dioxide, located overlying the underlayer.

Abstract: A developer for developing an electrostatic latent image, including a carrier which includes core particles, and a surface layer surrounding each of the core particles and containing an acrylic resin binder; and a toner which includes toner particles and an external additive of inorganic or organic fine particles present on each of the toner particles. Each of the toner particles comprises a colorant, a matrix of a first resin, and a plurality of domains of a second resin dispersed in the matrix and containing a wax. The first resin is substantially free of tetrahydrofuran insoluble matters and has a weight average molecular weight of 3,000 to 90,000.

Abstract: A carrier is provided including a core and a resin layer located overlying the core, wherein the carrier has a weight average particle diameter (Dw) of from 22 to 50 ?m, a ratio (Dw/Dp) of the weight average particle diameter (Dw) to a number average particle diameter (Dp) of from 1 to 1.30, a shape factor SF-1 of from 100 to 120, and a shape factor SF-2 of from 100 to 120, and wherein the carrier comprises core particles satisfying the following relationship 0.52<(d/D)<1.0 in an amount of from 0 to 10,000 ppm by number: wherein D (?m) represents a diameter of a circle having the same area as that of a projected image of a core particle and d (?m) represents a diameter of a circle having the same area as that of a projected image of a maximum hollow present in the core particle.

Abstract: A carrier for use with a toner as a two-component type developer for developing an electrostatic image, comprising spherical magnetic core particles, and a resin layer covering each of said core particles and containing at least two resistance controlling materials having different specific resistances, wherein each of the resistance controlling materials is in the form of particles having a number average particle diameter of no more than 1/10 of a number average particle diameter of the toner.

Abstract: A method to form an image using a trickle developing system, wherein (a) the toner comprises colorant particles with a volume median diameter of 3 to 8 ?m having first inorganic particles on surfaces of the colorant particles to form toner particles; (b) the carrier comprises magnetic particles with a weight average particle diameter (D4) of 20 to 40 ?m having second inorganic particles on surfaces of the magnetic particles to form carrier particles; and (c) an area ratio of element (A) based on a total area of surfaces of the carrier particles is 0.5 to 3.0 area % determined by using an X-ray analysis, provided that element (A) represents one or more elements commonly contained in the first inorganic particles and in the second inorganic particles.