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 cleaner-less image forming method includes forming an electrostatic latent image on a electrostatic latent image carrying member; developing the electrostatic latent image with a developer comprising a toner and a carrier to form a toner image; and transferring the toner image. The carrier has a median of an arithmetic average height distribution of from 0.45 to 0.65 ?m, and the toner includes an external additive and has an average circularity of 0.975 or more.

Abstract: There are described an image forming method and apparatus, which enable to form an electrophotographic image having high image density and excellent color reproducibility. The method includes: applying a uniform surface potential to an organic photoreceptor; irradiating light, having a wavelength in a range of 350-500 nm, on the photoreceptor, to form a latent image on the photoreceptor; and contacting a developing blush, containing toner and carrier, with the organic photoreceptor so as to form a visible toner image. The developing sleeve bears developing agent including the toner and the carrier. An absolute value of an electric charge potential of non-exposed area on the organic photoreceptor is in a range of 250-450 Volts and the developing sleeve is rotated in a counter direction, being counter to a rotating direction of the organic photoreceptor.

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 developing method including forming a magnetic brush of a two component developer comprising a toner and a magnetic carrier; and developing an electrostatic latent image with the magnetic brush, wherein the ratio (Anc/At) of the area (Anc) of the carrier-noncontact portion to the area of the development portion in which the electrostatic latent image can be developed by the magnetic brush is from 0.30 to 0.70, and the ratio (Avc/vs) of the average moving velocity (Avc) of carrier particles contacting the image bearing member to the moving velocity (vs) of the surface of the developer bearing member is from 0.8 to 1.1. Alternatively, it is possible that the ratio (Anc/At) is not greater than 0.50 and the ratio (Avc/vs) is from 0.3 to 1.1.

Abstract: An image forming method, comprising the steps of: agitating a mixture of toner particles and carrier particles so as to electrically charge the toner particles; forming a charged toner layer on a toner conveying roller by extracting the charged toner particles from the mixture; forming an electrostatic latent image on an image carrying member; and conveying the charged toner layer by the toner conveying roller so as to develop the electrostatic latent image on the image carrying member with charged toner; wherein the carrier particles are carrier particles each formed by dispersing magnetic fine powder in a binder resin and have a shape coefficient SF-1 of 1.0 to 1.2, a shape coefficient SF-2 of 1.1 to 2.5, and a volume-based median size of 10 to 100 ?m.

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.