Abstract: An image forming apparatus provided with a photosensitive member, a charging device for charging the photosensitive member, a developing device for developing an electrostatic image formed on the photosensitive member by a developer, a cleaning blade for removing the developer residual on the photosensitive member, a rubbing member provided upstream of the cleaning blade in the direction of rotation of the photosensitive member for rubbing the photosensitive member to assist the cleaning blade in cleaning, and a controller for controlling the surface temperature of the photosensitive member, wherein the photosensitive member has the HU (universal hardness value) of 150 N/mm2 or greater and 220 N/mm2 or less, and the elastic deformation rate of 43% or greater and 65% or less.

Abstract: The invention is to provide an image forming method of a long service life, a high image quality and a low running cost, capable of maintaining a stable cleaning performance over a prolonged period without causing an image deletion phenomenon, even with a image bearing member such as a photosensitive member, of a high durability (high strength and high abrasion resistance). The invention provides an image forming method characterized in that the image bearing member has a universal surface hardness HU of 150 to 220 N/mm2 and an elastic deformation ratio We of 40 to 65%, and, for a crossing angle ? (°) between a rotary axis of the contact charging roller and a rotary axis of the image bearing member, for a ratio A (weight %) of the transfer residual toner and the abrasive particles and for a contact pressure B (g/cm) of the cleaning blade, HU, We, A, B and ? satisfy the following relations (I), (II) and (III): (1/6000)×HU×We?A×B ??(I) A/B?? ??(II) 10?B?50.

Abstract: An image forming apparatus provided with a photosensitive member, a charging device for charging the photosensitive member, a developing device for developing an electrostatic image formed on the photosensitive member by a developer, a cleaning blade for removing the developer residual on the photosensitive member, a rubbing member provided upstream of the cleaning blade in the direction of rotation of the photosensitive member for rubbing the photosensitive member to assist the cleaning blade in cleaning, and a controller for controlling the surface temperature of the photosensitive member, wherein the photosensitive member has the HU (universal hardness value) of 150 N/mm2 or greater and 220 N/mm2 or less, and the elastic deformation rate of 43% or greater and 65% or less.

Abstract: An image forming apparatus provided with a photosensitive member, a charging device for charging the photosensitive member, a developing device for developing an electrostatic image formed on the photosensitive member by a developer, a cleaning blade for removing the developer residual on the photosensitive member, a rubbing member provided upstream of the cleaning blade in the direction of rotation of the photosensitive member for rubbing the photosensitive member to assist the cleaning blade in cleaning, and a controller for controlling the surface temperature of the photosensitive member, wherein the photosensitive member has the HU (universal hardness value) of 150 N/mm2 or greater and 220 N/mm2 or less, and the elastic deformation rate of 43% or greater and 65% or less.

Abstract: In a toner having toner particles which have toner base particles having at least a colorant and a binder resin, and an inorganic fine powder; the inorganic fine powder has a primary-particle average particle diameter of from 30 nm to 300 nm, and has particles having at least one of a cubic particle shape, a cube-like particle shape, a rectangular particle shape and a rectangle-like particle shape and having perovskite type crystals; and the inorganic fine powder has particles and agglomerates both having particle diameters of 600 nm or more, in a content of 0% to 1% by number.

Abstract: The invention is to provide an image forming method of a long service life, a high image quality and a low running cost, capable of maintaining a stable cleaning performance over a prolonged period without causing an image deletion phenomenon, even with a image bearing member such as a photosensitive member, of a high durability (high strength and high abrasion resistance). The invention provides an image forming method characterized in that the image bearing member has a universal surface hardness HU of 150 to 220 N/mm2 and an elastic deformation ratio We of 40 to 65%, and, for a crossing angle ? (°) between a rotary axis of the contact charging roller and a rotary axis of the image bearing member, for a ratio A (weight %) of the transfer residual toner and the abrasive particles and for a contact pressure B (g/cm) of the cleaning blade, HU, We, A, B and ? satisfy the following relations (I), (II) and (III): (1/6000)×HU×We?A×B??(I) A/B????(II) 10?B?50??(III).

Abstract: An image forming apparatus provided with a photosensitive member, a charging device for charging the photosensitive member, a developing device for developing an electrostatic image formed on the photosensitive member by a developer, a cleaning blade for removing the developer residual on the photosensitive member, a rubbing member provided upstream of the cleaning blade in the direction of rotation of the photosensitive member for rubbing the photosensitive member to assist the cleaning blade in cleaning, and a controller for controlling the surface temperature of the photosensitive member, wherein the photosensitive member has the HU (universal hardness value) of 150 N/mm2 or greater and 220 N/mm2 or less, and the elastic deformation rate of 43% or greater and 65% or less.

Abstract: In a toner having toner particles which have toner base particles having at least a colorant and a binder resin, and an inorganic fine powder; the inorganic fine powder has a primary-particle average particle diameter of from 30 nm to 300 nm, and has particles having at least one of a cubic particle shape, a cube-like particle shape, a rectangular particle shape and a rectangle-like particle shape and having perovskite type crystals; and the inorganic fine powder has particles and agglomerates both having particle diameters of 600 nm or more, in a content of 0% to 1% by number.

Abstract: In a process cartridge having a latent-image-bearing member and a developing device having a developer-holding part and a developing member, at a vertical section which bisects in the process cartridge the surface of the latent-image-bearing member with which surface the developing member is brought into pressure contact, a developer agitation and transport member has at least two rotary agitation and transport members having rotating shafts falling at right angles with the vertical section. Where, at the vertical section, the area of the developer-holding part is represented by S1 and the area of the part corresponding to the movable region of the rotary agitation and transport member is represented by S2, the ratio of S2 to S1, S2/S1, is from 0.8 to 0.99; and the ratio of a long side Sa to a short side Sb, Sa/Sb, of a circumparallelogram having a minimum area in respect to the area S1 in the vertical section is from 1.5 to 3.0.

Abstract: In a process cartridge having a latent-image-bearing member and a developing means having a developer-holding part and a developing member, at a vertical section which bisects in the process cartridge the surface of the latent-image-bearing member with which surface the developing member is brought into pressure contact, a developer agitation and transport member has at least two rotary agitation and transport means having rotating shafts falling at right angles with the vertical section. Where, at the vertical section, the area of the developer-holding part is represented by S1 and the area of the part corresponding to the movable region of the rotary agitation and transport means is represented by S2, the ratio of S2 to S1, S2/S1, is from 0.8 to 0.99; and the ratio of a long side Sa to a short side Sb, Sa/Sb, of a circumparallelogram having a minimum area in respect to the area S1 in the vertical section is from 1.5 to 3.0.

Abstract: A toner having a good chargeability stable against an environmental change is formed of toner particles each comprising at least a binder resin, a colorant, a release agent and a sulfur-containing polymer, and an external additive. The toner particles contain 100 to 30,000 ppm by weight thereof of at least one stabilizer element selected from the group consisting of magnesium, calcium, barium, zinc, aluminum and phosphorus. The toner particles may preferably be produced by suspension polymerization of a monomer composition containing the sulfur-containing polymer in an aqueous medium containing a dispersion stabilizer having the stabilizer element.

Abstract: An image forming method using a dry toner and exhibiting good quick-start and power economization characteristics is provided. The image forming method includes a heat-pressure fixing step using a rotatable electromagnetic induction heat-generation type heating member. The toner used therein is characterized by a moisture content of at most 3.00 wt. %, and viscoelasticities as represented by a storage modulus at 110° C. of G′ (110° C.) and a storage modulus at 140° C. of G′ (140° C.) satisfying: G′ (110° C.)≦1.00×106 dN/m2, and G′ (140° C.)≧7.00×103 dN/m3.

Abstract: A toner for developing electrostatic images is comprised of a binder resin and a wax. The binder resin contains as a primary component a polyester resin having a soft segment. The wax has, in its endothermic peaks at the time of temperature rise and exothermic peaks at the time of temperature drop in the DSC curve measured using a differential scanning calorimeter; (i) an endothermic onset temperature within the range of from 50° C. to 110° C.; (ii) at least one endothermic peak P1 within the range of from 70° C. to 130° C. at the time of temperature rise; and (iii) a maximum exothermic peak at the time of temperature drop, within the range of plus-minus 9° C. of the endothermic peak P1.

Abstract: A process for producing a polymerization toner, which comprises preparing a polymerizable-monomer composition which contains at least a polymerizable monomer and a colorant and does not contain any polymerization initiator, i) introducing the polymerizable-monomer composition into an aqueous medium to effect granulation, adding a polymerization initiator to the aqueous medium in the course of the granulation or after the granulation has been completed, or ii) adding a polymerization initiator in an aqueous medium, introducing the polymerizable-monomer composition into the aqueous medium to effect granulation, and then polymerizing the polymerizable-monomer composition having been granulated, to produce toner particles. In the process, the polymerization initiator is added in a specific time and a specific manner.

Abstract: A process for producing a polymerization toner, which comprises preparing a polymerizable-monomer composition which contains at least a polymerizable monomer and a colorant and does not contain any polymerization initiator, i) introducing the polymerizable-monomer composition into an aqueous medium to effect granulation, adding a polymerization initiator to the aqueous medium in the course of the granulation or after the granulation has been completed, or ii) adding a polymerization initiator in an aqueous medium, introducing the polymerizable-monomer composition into the aqueous medium to effect granulation, and then polymerizing the polymerizable-monomer composition having been granulated, to produce toner particles.

Abstract: A toner having a good chargeability stable against an environmental change is formed of toner particles each comprising at least a binder resin, a colorant, a release agent and a sulfur-containing polymer, and an external additive. The toner particles contain 100 to 30,000 ppm by weight thereof of at least one stabilizer element selected from the group consisting of magnesium, calcium, barium, zinc, aluminum and phosphorus. The toner particles may preferably be produced by suspension polymerization of a monomer composition containing the sulfur-containing polymer in an aqueous medium containing a dispersion stabilizer having the stabilizer element.

Abstract: An image forming method using a dry toner and exhibiting good quick-start and power economization characteristics is provided. The image forming method includes a heat-pressure fixing step using a rotatable electromagnetic induction heat-generation type heating member. The toner used therein is characterized by a moisture content of at most 3.00 wt. %, and viscoelasticities as represented by a storage modulus at 110° C. of G′ (110° C.) and a storage modulus at 140° C. of G′ (140° C.) satisfying: G′ (110° C.)≦1.00×106 dN/m2, and G′ (140° C.)≧7.00×103 dN/m3.

Abstract: A toner has toner particles and an external additive. The toner particles have a weight-average particle diameter of from 4 &mgr;m to 9 &mgr;m. The external additive has (i) first, small-particle-diameter hydrophobic fine silica particles (A) having a BET specific surface area of from 100 m2/g to 350 m2/g, having been treated with a silane, (ii) second, large-particle-diameter hydrophobic fine silica particles (B) having a BET specific surface area of from 15 m2/g to 80 m2/g, having been treated with a silicone oil, and (iii) fine alumina particles (C) having a BET specific surface area of from 50 m2/g to 150 m2/g.

Abstract: A yellow toner suitable for electrophotography is formed by dispersing a yellow colorant mixture in a binder resin.

Abstract: An electrophotographic toner is formed of toner particles each comprising at least a binder resin, a colorant and a release agent, and a low-crystalline aromatic metal compound present at surfaces of the toner particles. The toner has an average circularity of at least 0.955, and the low-crystalline aromatic metal compound has an X-ray diffraction characteristic free from peaks exhibiting a measurement intensity of at least 10000 cps and a half-value half-width of at most 0.3 deg. in a range of measurement angles 2&thgr; of 6 to 40 deg. Because of the low crystallinity, the aromatic metal compound is uniformly applied onto the toner particle surfaces to stabilize the chargeability and transferability of the toner.