An image forming apparatus includes a developer, a development device, and an image bearing member. The developer includes an initial developer containing an initial carrier and a replenishment developer containing a replenishment carrier. The initial carrier has a surface roughness Sa1 of at least 0.3 ?m and no greater than 1.0 ?m. A ratio Sa1/Sa2 of the surface roughness Sa1 of the initial carrier to a surface roughness Sa2 of the replenishment carrier is at least 1.2 and no greater than 3.4. The packing volume Vp calculated from equation (1)Vp=100?Y/(Z?DS) was at least 40% and no greater than 70%. In equation (1), Y represents an amount of the developer conveyed by a developer bearing member. Z represents an apparent density of the initial developer. DS represents a width of a space between the developer bearing member and the image bearing member.

Provided is a carrier for electrostatic charge image development which provides a two-component developer having a high electric charge amount, a suppressed variation in an electric charge amount caused by an environmental change, and excellent durability, even if a low temperature fixable toner is used. A carrier for electrostatic charge image development of the present invention includes: carrier particles in which a core particle surface is coated with a coating material containing a resin, wherein the coating material contains phosphorus element, and the resin contains structural units derived from an alicyclic (meth)acrylic acid ester compound.

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.

An electrostatic charge image developer includes: a toner that includes toner particles which contain a polyester resin and a styrene (meth)acrylic resin and form a sea-island structure which includes a sea portion containing the polyester resin and an island portion containing the styrene (meth)acrylic resin on a surface of the toner particle, and has an exposure rate of the styrene (meth)acrylic resin in a range of from about 5 atom % to about 20 atom %; and an external additive, and a carrier whose fluidity and bulk density under environment of a temperature of 25 C. and a humidity of 50% satisfy Expression: 65.0fluiditybulk density72.5.

In a two-component developer, external additive particles of toner particles include resin particles. The resin particles contain a crosslinked resin including a repeating unit derived from a crosslinking agent. Carrier particles each include a carrier core and a coat layer covering a surface of the carrier core. The coat layers 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 within a range of 100 nm to 500 nm. The barium titanate particles have a content within a range of 5 parts by mass to 45 parts by mass relative to 100 parts by mass of the coating resin. A rate of a mass of the coat layers to a mass of the carrier cores is greater than 0.0% by mass and no greater than 4.9% by mass. The carrier cores have a shape factor within a range of 34.0% to 85.0%.

In a two-component developer, external additive particles of toner particles include silica particles. The silica particles have a number average primary particle diameter of at least 30 nm and no greater than 120 nm. 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 at least 100 and no greater than 500 nm. The barium titanate particles have a content of at least 5 parts by mass and no greater than 45 parts by mass relative to 100 parts by mass of the coating resin. A rate of a mass of the coat layers to a mass of the carrier cores is at least 0.09% by mass and no greater than 4.90% by mass. A coverage rate of the carrier cores is at least 80.0% and less than 100.0%.

An image forming method is provided that includes: developing an electrostatic latent image formed on an image bearer, with use of a developer containing a carrier and toner, the carrier having a core material particle and a covering layer, the covering layer covering the core material particle and containing an antimony-containing particle; and supplying the carrier to the developer.

A two-component developer contains a carrier containing carrier particles and a toner containing toner particles. The carrier particles each include a carrier core and a coat layer covering the surface of the carrier core. The coat layers contain a silicone resin. The toner particles each include a toner mother particle and an external additive attached to the surface of the toner mother particle. The external additive contains specific resin particles. The specific resin particles contain a crosslinked resin. The specific resin particles have a number average primary particle diameter of at least 37 nm and no greater than 103 nm. The specific resin particles have a content of at least 0.6 parts by mass and no greater than 1.0 part by mass relative to 100 parts by mass of the toner mother particles.

A carrier contains a core material with a surface roughness Rz of from 2.0 to 3.0 ?m; and a coating layer to cover the core material, the coating layer comprising an antimony-containing particle.

A carrier is provided including a core particle and a resin layer coating the surface of the core particle. The resin layer includes fine metal particles, and a detected metal element amount A obtained by X-ray photoelectron spectrometry of the surface of the carrier is in a range of 4.0 atomic %A20.0 atomic % and an average major-axis length B of the fine metal particle exposing from the resin layer is in a range of 100 nmB800 nm.