Abstract: A magnetic carrier is provided which uses a toner having high coloring power and enables development to be performed at low electric field intensity and can form high quality images while keeping gradation characteristics. The magnetic carrier includes magnetic carrier particles including at least porous magnetic core particles and a resin. The electric field intensity just before the break-down of the magnetic carrier is 1,300 V/cm or more and 5,000 V/cm or less.

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: A fixing method and a fixing device is provided in which an unfixed toner image formed on a recording medium is heat-pressure-fixed by using a fixing unit, wherein the unfixed toner image is fixed when the recording medium passes through at least two fixing units arranged in series in a conveying direction of the recording medium. Specific relations are satisfied between a maximum temperature on the recording medium when the recording medium passes through a first fixing unit, a maximum temperature on the recording medium when the recording medium passes through a second fixing unit, a minimum temperature on the recording medium during a time period commencing on ejection of the recording medium from the first fixing unit and ending on entry of the recording medium into the second fixing unit and properties of the toner.

Abstract: It is an object of the present invention to provide a toner having the transfer efficiency and the cleanability in combination, exhibiting excellent stress resistance, and ensuring the low-temperature fixing. A toner characterized in that the average circularity of the above-described toner is 0.960 or more, and 0.985 or less, where the average circularity is analyzed by dividing particles having a circle equivalent diameter of 1.98 ?m or more, and 200.00 ?m or less, the number A of toners having a circularity of 0.990 or more, and 1.000 or less is 25.0 percent by the number or less, and the percentage of the number of particles B having a circle equivalent diameter of 0.50 ?m or more, and 1.98 ?m or less relative to the total particles of 0.50 ?m or more, and 200.00 ?m or less is 10.0 percent by the number or less.

Abstract: In the formation of images by a two-component development system, provided is a magnetic carrier that can be used to output an image which has sufficient density, in which few white spots are present in a low-density portion located near the boundary between a high-density region and a low-density region, and in which the low-density portion has good graininess. The magnetic carrier contains magnetic carrier particles each of which has resin and a magnetic particle. The magnetic particle contains ferrite phases and phases comprising a perovskite-structured compound. The ferrite phases and phases comprising a perovskite-structured compound are combined.

Abstract: A magnetic carrier and a two-component developer are provided which have remedied blank areas, fog after leaving, carrier sticking during running, and image density variations before and after running. The magnetic carrier has magnetic carrier particles having at least porous magnetic core particles and a resin. The magnetic carrier particles satisfying the specific conditions (a), (b) and (c) where, in a reflected electron image of cross sections of the magnetic carrier particles as photographed with a scanning electron microscope, straight lines that divide a cross section of a magnetic carrier particle into 72 at intervals of 5° are drawn from a reference point of the cross section thereof toward the surface of the magnetic carrier particle; the magnetic carrier particles being contained in an amount of 60% by number or more.

Abstract: An object of the present invention is to provide a two-component developer which can achieve a high-definition image with a smaller toner laid-on level than a conventional one, provides a color gamut comparable to that of printing, can respond to an increase in printing speed, and allows an image with a stable tinge to be formed even in long-term use. The object can be achieved by a two-component developer containing a cyan toner and a magnetic carrier, the two-component developer being characterized in that the cyan toner has the following characteristics: (i) when the concentration of the cyan toner in a solution of the cyan toner in chloroform is represented by Cc (mg/ml) and the absorbance of the solution at a wavelength of 712 nm is represented by A712, a relationship between Cc and A712 satisfies the relationship of 2.00<A712/Cc<8.15; (ii) the lightness L* and chroma C* of the cyan toner determined in a powder state satisfy the relationships of 25.0?L*?40.0 and 50.0?C*?60.

Abstract: Provided is a magnetic carrier giving a high quality image free of density variation without the occurrence of fogging or carrier adhesion and having excellent dot reproducibility even during long-term use. The magnetic carrier has magnetic carrier particles produced by filling pores of porous magnetic core particles with a resin. The magnetic carrier contains 80% by number or more of the magnetic carrier particles satisfying the specific conditions (a) and (b) when 18 straight lines passing through a reference point of a cross section of the magnetic carrier particle are drawn at intervals of 10° in a reflected electron image of the cross section of the magnetic carrier particle photographed by a scanning electron microscope.

Abstract: An image forming apparatus, wherein the following formulae are satisfied: 0.22 ? ( M / S ) L ? 0.4 , ? ( Q M ) L = Vc ( Lt 2 ? ? 0 ? ? t + Ld ? 0 ? ? d ) × ( M S ) L ( Dt ? ? max - Dt 0.1 ) { ? × ( M S ) L - 0.1 } ? ( Lt 2 ? ? 0 ? ? t + Ld ? 0 ? ? d ) × ( M S ) L 500 ? ?? ? ( Dt ? ? max - Dt 0.1 ) { ? × ( M S ) L - 0.1 } ? ( Lt 2 ? ? 0 ? ? t + Ld ? 0 ? ? d ) × ( M S ) L 150 ?? ? ( Dt ? ? max - Dt 0.1 ) { ? × ( M S ) L - 0.

Abstract: A two-component developer containing a cyan toner and a magnetic carrier, wherein the cyan toner has the characteristics: (i) when the concentration of the cyan toner in a solution of the cyan toner in chloroform is represented by Cc (mg/ml) and the absorbance of the solution at a wavelength of 712 nm is represented by A712, a relationship between Cc and A712 satisfies the relationship of 2.00<A712/Cc<8.15; (ii) the lightness L* and chroma C* of the cyan toner determined in a powder state satisfy the relationships of 25.0?L*?40.0 and 50.0?C*?60.0; and (iii) the absolute value for the triboelectric charge quantity of the cyan toner measured by a two-component method using the cyan toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.

Abstract: When a surface of magnetic carrier core particles is coated with coating resin composition particles, the coating is conducted so that a surface of the magnetic carrier is free from cracks and chips and has fewer residual resin composition particles and a coating is uniform. In the method, a rotor having a plurality of stirring members on a surface thereof is rotated to coat the surface of magnetic carrier core particles with the resin composition particles. When the coating is conducted, while repeatedly conducting transportation in a direction of a driver and transportation in an anti-driver direction, the surface of the magnetic carrier core particles is coated with the resin composition. The resin composition particles has a 50% particle diameter (D50) based on volume of 0.2 ?m or more to 6.0 ?m or less and the proportion of particles of 10.0 ?m or more is 2.0% by volume or less.

Abstract: A magnetic carrier which has magnetic carrier particles each having at least porous magnetic core particles and a resin, in which, in a backscattered electron image of the magnetic carrier particles, photographed with a scanning electron microscope as taken at an accelerating voltage of 2.0 kV, magnetic carrier particles having area proportion S1 found from a specific expression (1) of from 0.5 area % or more to 8.0 area % or less are in a proportion of 8.0% by number or more in the magnetic carrier, an average proportion Av1 of the total area of portions having a high luminance which come from a metal oxide on the magnetic carrier particles to the total projected area of the magnetic carrier particles is from 0.5 area % or more to 8.0 area % or less, and an average proportion Av2 found from a specific expression (2) is 10.0 area % or less.

Abstract: Provided is a two-component developer containing: a magnetic carrier obtained by coating a magnetic core with a resin; and toner, in which: the magnetic core contains at least a ferrite component and at least one kind of an oxide selected from the group consisting of SiO2 and Al2O3; the content of the oxide is 4.0 mass % or more and 40.0 mass % or less with respect to the magnetic core; the magnetic core has a specific resistance of 5.0×104 ?·cm or more and 5.0×108 ?·cm or less at the time of the application of 1,000 V/cm; the magnetic carrier has an intensity of magnetization in 79.6 kA/m of 40.0 Am2/kg or more and 65.0 Am2/kg or less, and a residual magnetization after the application of an external magnetic field of 79.6 kA/m of 3.0 Am2/kg or less; and the toner has a weight-average particle diameter (D4) of 3.0 gin or more and 10.0 ?m or less and an average circularity of 0.940 or more and 0.990 or less.

Abstract: In a method for coating electrophotographic carrier core surfaces with a resin composition by rotating a rotator having a plurality of agitating blades on its surface in a casing; a coating treatment material that is introduced to a space defined between the rotator and the casing is in a packing of from 50% to 98% by volume; at the time of coating treatment, the electrophotographic carrier core surfaces are coat-treated with the resin composition while being put forward and put backward; and the electrophotographic carrier cores and the resin composition are, at the time of coating treatment, temperature-controlled at a specific temperature T (° C.) or below. This method enables the electrophotographic carrier core surfaces to be more uniformly coated with a coating resin.

Abstract: The present invention provides an image of high image quality by using a magnetic carrier coated with a novel coating resin composition. Further, the present invention stably provides a good image which is hardly influenced by environmental fluctuation and long-term use and has a superior stability of a charging amount when left to stand especially under high temperature and high humidity environments. The present invention also provides a magnetic carrier characterized in that a carrier core surface is coated with a copolymer containing at least, as copolymerization components, an acrylic monomer having a specific structure and an acrylic macromonomer having a specific structure.

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 cyan toner determined in a powder state satisfy the relationships of 35.0?L*?45.0 and 60.0?C*?72.0; 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 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: 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 magnetic carrier having magnetic carrier particles each containing at least a magnetic core particle and a resin; the magnetic carrier having a resistivity of from 1.0×106 ?·cm or more to 1.0×1010 ?·cm or less at an electric-field intensity of 1.0×103 V/cm as found by measuring dynamic impedance; electric-field intensity E(109) at which the resistivity of the magnetic carrier comes to 1.0×109 ?·cm being 2.0×104 V/cm or less, and electric-field intensity E(108) at which the resistivity of the magnetic carrier comes to 1.0×108 ?·cm being from 5.0×103 V/cm or more to 2.8×104 V/cm or less; and the electric-field intensity E(108) and the electric-field intensity E(109) being in a ratio, E(108)/E(109), of from 1.0 or more to 5.0 or less.

Abstract: A two-component developer containing a cyan toner and a magnetic carrier, wherein the cyan toner has the characteristics: (i) when the concentration of the cyan toner in a solution of the cyan toner in chloroform is represented by Cc (mg/ml) and the absorbance of the solution at a wavelength of 712 nm is represented by A712, a relationship between Cc and A712 satisfies the relationship of 2.00<A712/Cc<8.15; (ii) the lightness L* and chroma C* of the cyan toner determined in a powder state satisfy the relationships of 25.0?L*?40.0 and 50.0?C*?60.0; and (iii) the absolute value for the triboelectric charge quantity of the cyan toner measured by a two-component method using the cyan toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.