A carrier for a developer of an electrostatic latent image, the carrier including: core particles having magnetism; and a coating layer coating a surface of each of the core particles, wherein the coating layer includes two or more kinds of inorganic particles, at least one kind of inorganic particles among the two or more kinds of inorganic particles is inorganic particles A having conductivity and a peak particle diameter of from 300 nm through 1,000 nm, and surface roughness of the carrier calculated by Formula 1 below is from 1.10 m.sup.2/g through 1.90 m.sup.2/g,
CFFormula 1
where C is a BET specific surface area (m.sup.2/g) of the carrier and F is a BET specific surface area (m.sup.2/g) of the core particles.

Carrier particles each include a carrier core having recesses in a surface thereof, and first and second coat layers covering the surface of the carrier core. The first and second coat layers are in a multi-layer structure in which the first coat layer and the second coat layer cover the surface of the carrier core in the stated order. The first coat layer entirely covers the surface of the carrier core. The second coat layer selectively covers regions of a surface of the first coat layer that correspond to the recesses in the surface of the carrier core. The first coat layer contains a first resin. The second coat layer contains a second resin. The second coat layer has a lower electric resistance than the first coat layer.

A carrier including a resin layer including at least one kind of particles, wherein the at least one kind of the particles are particles of barium sulfate, wherein an amount of Ba detected is 0.3 atomic % or greater in a Ba analysis through X-ray photoelectron spectroscopy (XPS) of the carrier, and wherein circle-equivalent diameters of the particles of the barium sulfate are 400 nm or greater but 900 nm or smaller.

In a two-component developer, external additive particles of toner particles include resin particles containing a thermoplastic resin. Coat layers of carrier particles contain a coating resin and barium titanate particles. The coating resin includes a silicone resin. The barium titanate particles have a number average primary particle diameter of 100-500 nm. The barium titanate particles have a content of 4-45 parts by mass relative to 100 parts by mass of the coating resin. The rate of the mass of the coat layers to the mass of the carrier cores is 0.10-4.90% by mass. The average of coverage rates of the carrier cores is at least 80.0% and less than 100.0%.

An object of the present invention is to provide a ferrite carrier core material for an electrophotographic developer having desired resistance properties and charging properties with small environmental variation of resistivity and charge amount while maintaining the advantages of ferrite carriers, a ferrite carrier for an electrophotographic developer, an electrophotographic developer using the ferrite carrier, and a method for manufacturing the ferrite carrier core material for an electrophotographic developer. In order to solve the problem, a ferrite carrier core material comprising ferrite particles containing 15 mass % or more and 25 mass % or less of Mn, 0.5 mass % or more and 5.0 mass % or less of Mg, 0.05 mass % or more and 4.0 mass % of Sr, and 45 mass % or more and 55 mass % or less of Fe, with Zr localized in the surface thereof is used.

A two-component developer includes toner particles and carrier particles. The toner particles each include a toner mother particle and first resin particles. The carrier particles each include a carrier mother particle and second resin particles. An amount of the second resin particles is at least 0.010 parts by mass and no greater than 0.100 parts by mass relative to 100 parts by mass of the carrier mother particles. The first resin particles and the second resin particles have a number average primary particle diameter of at least 40 nm and no greater than 100 nm and a blocking rate (measurement temperature: 160 C.) of less than 30% by mass. A difference in blocking rate between the first resin particles and the second resin particles is no greater than 5% by mass, and a difference in number average primary particle diameter therebetween is no greater than 5 nm.

A developing device, including: a developer containing toner and carrier; and developer bearer configured to have surface thereof bear the developer and endlessly move, and to develop latent image over surface of latent image bearer by supplying toner in developer to latent image in developing region facing the latent image bearer, wherein carrier contains fine particles, value X in volume resistivity R (=10.sup.X) (?.Math.cm) of carrier is 11.5-16.0, developer bearer includes: magnetic field generating unit including a plurality of magnetic poles; and developing sleeve having a cylindrical shape enclosing magnetic field generating unit, and configured to bear developer over outer circumferential surface of cylindrical shape by magnetic force of the magnetic field generating unit and perform surface moving by rotating relative to developing device body, and developing device includes developing sleeve voltage applying unit configured to apply AC component-containing voltage to developing sleeve.

Provided is a carrier for a developer of an electrostatic latent image, the carrier including a core particle, and a resin layer covering the core particle, where the resin layer includes metal compound particles, wherein the metal compound particles include magnesium compound particles or barium compound particles, and an exposed amount B (atomic %) of the magnesium or the barium on a surface of the carrier particle satisfies a relationship below:

10.0B1.2.

The present invention provides a two-component developer for developing an electrostatic charge image, which includes a toner and a carrier, wherein the toner contains an amorphous resin and a crystalline resin as binder resins and an inorganic particle as external additive particle, and the carrier has a surface to which silica particles having a number average particle diameter of 10 to 30 nm are attached in an amount in the range of the following Equation (1): 5 at %S110 at %, wherein S1 represents a concentration of Si element as measured by XPS and indicates an amount of silica on the surface of the carrier.

A two-component developing agent contains a toner that contains a pulverized toner, the pulverized toner containing at least one type of polyester resin, a styrene-based resin or an aromatic petroleum resin, and Fisher-Tropsch wax, and a carrier that contains a silicone resin covering layer containing conductive fine powder.