Abstract: To provide a two-component developer which can maintain the triboelectrification property effectively and can inhibit the generation of fogging effectively even when image formation is performed continuously for a long time by inhibiting inorganic fine particles from burying into a covering resin layer of a carrier to control the degradation of the carrier, and to provide an image forming method and an image forming apparatus using the same. A two-component developer comprising toner particles, a carrier, inorganic fine particles and resin fine particles; and an image forming method and an image forming apparatus using the same are provided.

Abstract: An object of the present invention is to provide a two-component developer that suppresses burying of an external additive into toner particles and a change in charging performance of a toner with time, and secures stable development performance. To achieve this object, the two-component developer of the present invention including a toner containing resin microparticles and silica microparticles and a carrier containing resin coat layers is adjusted so that a rate of change ?A % in BET specific surface area A (m2/g) of the toner (=((A120?A1)/A1)×100) and a rate of change ?C % in charge quantity C (?C/g) of the carrier (=((C120?C1)/C1)×100) when a mixture of the toner and the carrier is stirred and mixed by a TURBULA shaker mixer are both within 10%.

Abstract: A magnetic toner contains, as a magnetic powder, magnetic iron oxide having an octahedral particle shape and an average particle diameter of 0.21 ?m or larger and containing 18% or more by weight of FeO. The magnetic toner is so prepared as to have a bulk density A (g/cm3) and a magnetic powder content B (% by weight) that fulfill the formulae 0.8?A/B×100?1.6 and 35?B?50. This alleviates the reddishness of images produced with the magnetic toner, and alleviates the disturbance of a thin toner layer on a developing sleeve and thus the fogging resulting therefrom.

Abstract: A magnetic toner contains, as a magnetic powder, magnetic iron oxide having an octahedral particle shape and an average particle diameter of 0.21 ?m or larger and containing 18% or more by weight of FeO. The magnetic toner is so prepared as to have a bulk density A (g/cm3) and a magnetic powder content B (% by weight) that fulfill the formulae 0.8?A/B×100?1.6 and 35?B?50. This alleviates the reddishness of images produced with the magnetic toner, and alleviates the disturbance of a thin toner layer on a developing sleeve and thus the fogging resulting therefrom.

Abstract: A magnetic toner contains, as a magnetic powder, magnetic iron oxide having an octahedral particle shape and an average particle diameter of 0.21 ?m or larger and containing 18% or more by weight of FeO. The magnetic toner is so prepared as to have a bulk density A (g/cm3) and a magnetic powder content B (% by weight) that fulfill the formulae 0.8?A/B×100?1.6 and 35?B?50. This alleviates the reddishness of images produced with the magnetic toner, and alleviates the disturbance of a thin toner layer on a developing sleeve and thus the fogging resulting therefrom.

Abstract: A developing apparatus has a developer supporting member 41 with a surface roughness RZ in the range from 3.0 to 5.5 &mgr;m and a one-component developer T with a bulk density in the range from 0.35 to 0.55 g/ml, and an image is developed by forming a layer of the developer T on the developer supporting member 41. This makes it possible to form a thin toner layer stably despite changes in ambient conditions, and to prevent low image density and fogging. The absolute value of the amount of electric charge with which the developer T is charged is preferably in the range from 3.0 to 10.0 &mgr;C/g. The developer supporting member 41 is made preferably of stainless steel.

Abstract: A magnetic toner contains, as a magnetic powder, magnetic iron oxide having an octahedral particle shape and an average particle diameter of 0.21 &mgr;m or larger and containing 18% or more by weight of FeO. The magnetic toner is so prepared as to have a bulk density A (g/cm3) and a magnetic powder content B (% by weight) that fulfill the formulae 0.8≦A/B×100≦1.6 and 35≦B≦50. This alleviates the reddishness of images produced with the magnetic toner, and alleviates the disturbance of a thin toner layer on a developing sleeve and thus the fogging resulting therefrom.

Abstract: A developing apparatus has a developer supporting member 41 with a surface roughness RZ in the range from 3.0 to 5.5 &mgr;m and a one-component developer T with a bulk density in the range from 0.35 to 0.55 g/ml, and an image is developed by forming a layer of the developer T on the developer supporting member 41. This makes it possible to form a thin toner layer stably despite changes in ambient conditions, and to prevent low image density and fogging. The absolute value of the amount of electric charge with which the developer T is charged is preferably in the range from 3.0 to 10.0 &mgr;C/g. The developer supporting member 41 is made preferably of stainless steel.

Abstract: In a magnetic one-component toner containing at least a binder resin, a charge control resin, and a magnetic powder, the charge control resin has a weight-average molecular weight of 1.5×104 or less, contains 8 to 15% by weight of functional groups, and is added in 5 to 20 parts by weight to 100 parts by weight of the binder resin. This makes the toner highly safe for humans and the environment and excellent in fixability and electric chargeability.