Abstract: Provided is a developing device which can prevent the occurrence of a phenomenon of an excessive increase of a developer quantity in a developer standby space, thereby acquiring a stable image. The developing device comprises a developer agitation-transfer unit, a developer roller, a developer feeding roller, a developer guide member and a space forming member. The developing device is characterized in that the developer feeding roller rotates to transfer the developer transferred by the agitation-transfer means, upward from the clearance between the developer feeding roller and the developer guide member, and in that, when the developer standby space formed in the device is filled with the developer transferred by the developer feeding roller, the developer feeding roller is rotated to carry the developer, which overflows from the developer standby space, and to move the same in the direction away from the developer roller, so that the developer is once discharged from the developer standby space.

Abstract: An electrostatic image developing toner contains toner particles containing a polyester resin having a repeating unit deriving from a dicarboxylic acid and a repeating unit deriving from a rosin diol, and an external additive containing silica particles, wherein a weight average molecular weight (Mw) of the soluble matter in tetrahydrofuran of the toner is from about 60,000 to about 200,000.

Abstract: To provide a toner, which contains a binder resin, a colorant, and a releasing agent, wherein the binder resin contains a low molecular weight resin component, where the low molecular weight resin component has a resin softening coefficient (A), represented by the following formula (1), satisfying A>0.165, and has storage elastic modulus (dyne/cm2) G?(Tfb) satisfying G?(Tfb)?1×104 where Tfb is a flow onset temperature (° C.) of the low molecular weight resin component as measured by a capillary rheometer: A=|[ln G?(r1)?ln G?(r2)]/(T1?T2)|??Formula (1) (where T1 is temperature (° C.) at which storage elastic modulus G?(r1) is 1×105 (dyne/cm2) and T2 is temperature (° C.) at which storage elastic modulus G?(r2) is 1×103 (dyne/cm2) as measured by means of a viscoelasticity measuring device with measuring frequency of 1 Hz, and measuring distortion of 1 deg; and ? represents an absolute value.

Abstract: A polyester resin for a toner including: a repeating unit derived from a dicarboxylic acid component; and a repeating unit derived from a diol component represented by Formula 1: wherein each of R1 and R2 independently represents a hydrogen atom or a methyl group, each of L1, L2 and L3 independently represents a divalent linking group selected from the group consisting of carbonyl groups, ester groups, ether groups, sulfonyl groups, substituted or unsubstituted chained alkylene groups, substituted or unsubstituted cyclic alkylene groups, substituted or unsubstituted arylene groups, and combinations thereof, L1 and L2 or L1 and L3 optionally forms a ring, and each of A1 and A2 independently represents a rosin ester group, wherein the solubility parameter (SP) value is from 9.1 to 9.7.

Abstract: An electrostatic image developing toner includes (A) an amorphous polyester resin containing at least a repeating unit derived from a dicarboxylic acid component and a repeating unit derived from a dialcohol component represented by the specific formula, and (B) an amorphous polyester resin differing in the weight average molecular weight from the amorphous polyester resin (A), wherein the difference (absolute value) in the weight average molecular weight between the amorphous polyester resin (A) and the amorphous polyester resin (B) is from about 30,000 to about 100,000.

Abstract: There is provided a polyester resin for a toner, including: a polycondensate of a polyvalent carboxylic acid component and a polyhydric alcoholic component, wherein the polyhydric alcoholic component contains a rosin diol represented by the following Formula (1) and a content of the rosin diol is 80 mole % to 100 mole % based on the total polyhydric alcoholic component. wherein, each of R1 and R2 independently represents a hydrogen atom or a methyl group; L1 represents a divalent linking group having the following Formula (I); each of L2 and L3 independently represents a divalent linking group selected from the group consisting of carbonyl groups, carboxyl groups, ether groups, sulfonyl groups, substituted or unsubstituted chained alkylene groups, substituted or unsubstituted cyclic alkylene groups, substituted or unsubstituted arylene groups, and combinations thereof; and each of A1 and A2 independently represents a rosin ester group.

Abstract: A toner set for electrophotography, including a black toner; a yellow toner; a magenta toner; a cyan toner; and a bright yellow toner, wherein the magenta toner includes a magenta colorant mainly including C.I. Pigment Red 122, the yellow toner has a hue angle of from 93 to 100° and the bright yellow toner has a hue angle of from 60 to 85° in L*a*b* color system.

Abstract: An electrostatic image developing carrier includes a ferrite particle that contains magnesium element in an amount of about 3.0 wt % or more and about 10.0 wt % or less and manganese element in an amount of about 0.2 wt % or more and less than about. 1.0 wt %; and a resin layer that covers the ferrite particle.

Abstract: Disclosed is a process for production of a decolorable toner, including: aggregating dispersed fine particles of a color material comprising at least a color-forming compound, a color-developing agent and a decoloring agent with dispersed fine particles comprising at least a binder resin comprising a polyester resin to form aggregates in an aqueous medium, adding a reactive polymer having an oxazoline group in to the aqueous medium, and fusing the aggregates in the aqueous medium. As a result, it becomes possible to produce a decolorable toner which suppresses the generation of fine powder due to the release of fine particles of an erasable color material from the toner.

Abstract: Disclosed is a toner obtained by coating surfaces of core particles including at least a binder resin having a carboxyl group and a coloring agent with successive coatings of a water-soluble crosslinking agent capable of crosslinking with a carboxyl group and a water-soluble polymer having a carboxyl group, which have been successively applied on the core particles and crosslinked with each other. The thus-formed toner is provided with a good harmony of favorable fixability represented by a low lowest fixable temperature and favorable storage stability represented by little aggregation after standing at 50° C. for 8 hours.

Abstract: Disclosed is a decolorable toner produced by aggregating dispersed fine particles of a color material containing at least a color-forming compound, a color-developing agent and a decoloring agent with dispersed fine particles containing at least a binder resin having a carboxyl group, then adding a compound having a carbodiimide group or an epoxy group reactive with the carboxyl group of the binder resin, and thereafter fusing the aggregate particles, respectively in an aqueous medium. The thus obtained decolorable toner can suppress the generation of fine powder by the release of erasable color material fine particles from the toner particles.

Abstract: A toner including: a base resin; and charge-controlling resin particles contained in the base resin, wherein the toner is in shape of particles, and the charge-controlling resin particles are present in a region of each toner particle which is 500 nm in depth from a surface of the toner particle and an average of amounts of the charge-controlling resin particles present in the regions of the toner particles is 20% by volume to 70% by volume, wherein an average of embedment rates of the charge-controlling resin particles in the toner particles is 90% or higher, where each embedment rate is an average of embedment rates of the charge-controlling resin particles in each toner particle, and wherein the charge-controlling resin particles have a charge amount of 60 ?C/m2 or more as measured by a blow-off method.

Abstract: According to one embodiment, a developing agent includes a toner core particle containing a binder resin having a carboxyl group and a coloring agent and a surface layer formed on the toner core particle. The surface layer is formed by crosslinking the toner core particle, a water-soluble polymeric crosslinking agent which crosslinks with a carboxyl group and a water-soluble polymer having a carboxyl group in an aqueous medium. The developing agent can be fixed by a fixing device having a release oil applied thereto.

Abstract: A method of preparing carrier for electrophotography, which includes a core material and a coating material layer formed on the surface of the core material, including coating a coating material of the coating material layer on the core material; and burning the coating material by an induction heater, wherein the induction heater applies an alternative current to parallely-located plural coil circuits including a conductive wire including the shape of a coil to generate a magnetic line changing its direction and intensity for inductively heating the core material to heat the coating material.

Abstract: A developing unit includable in a process cartridge and in an image forming apparatus includes a developer bearing member including a magnetic field generator and a nonmagnetic hollow member, a developer container, an agitation/conveyance member, and a developer regulating member. The magnetic field generator has first and second magnetic poles to generate respective magnetic forces for removing the developer from the developer bearing member after the developer passes the development region. A developer-releasing region releases the developer from the developer bearing member using a release force. The developer is disposed higher than a surface of the developer in the developer storing chamber. A component of a magnetic flux density of the magnetic field generated by the magnetic field generator in a direction normal to the developer-releasing region is directed to a same direction as the first and second magnetic poles across the developer-releasing region without forming a local maximum point.

Abstract: An electrostatic charge image development carrier includes magnetic core particles and a resin coating layer that contains titanium dioxide particles doped with niobium and coats each of the magnetic core particles.

Abstract: A resin for use in toner is provided. The resin comprises an oligomer segment and a soft segment. The oligomer segment comprises a polyhydroxycarboxylic skeleton and an aromatic diol skeleton.

Abstract: A toner set has toners used in an image forming method by forming a toner image with toners of several colors and fixing the toner image onto a recording medium. The toners include first and second toners of different colors. The first and second toners contain toner base particles including a binding resin, a colorant and a wax. The colorant of the first toner contains a quinacridone pigment. The wax includes a carnauba wax and a wax other than the carnauba wax. The base particles of the first toner have a mass % Wq1 of carnauba wax and Wo1 of the other wax and the base particles of the second toner have a mass % Wq2 of carnauba wax and Wo2 of the other wax. These mass % values are selected to satisfy the following: Wq1/(Wq1+Wq2)<Wo1/(Wo1+Wo2) 3?Wo1+Wo2<Wq1+Wq2?10.

Abstract: In accordance with some embodiments, a toner including a first binder resin, a release agent, a release agent dispersing resin, and a colorant is provided. The first binder resin includes an amorphous polyester resin (a) having a polyhydroxycarboxylic acid skeleton in its main chain. The polyhydroxycarboxylic acid skeleton comprises optically-active monomers having an optical purity X of 80% by mole or less. The optical purity X is represented by the following formula: X (% by mole)=|X(L-form)?X(D-form)| wherein X(L-form) and X(D-form) represent ratios (% by mole) of L-form and D-form optically-active monomers, respectively. The release agent includes an ester of a fatty acid having an average carbon number of 18 to 24 with glycerin or a polyglycerin having an average polymerization degree of 2 to 10. The ester has a melting point of 55 to 80° C.

Abstract: An electrostatic charge image developing toner including: toner particles including a binder resin and a colorant; polytetrafluoroethylene particles in which a content of perfluorooctanoic acid and a salt thereof is 0.5 ppm or less; and silica particles in which a content of water is from 0.1% by weight to 10% by weight at an ambient temperature of 20° C. and an ambient humidity of 20%.

Abstract: A developing apparatus includes: a housing which contains toner; a toner supporting roller; and a regulating blade, wherein bias voltage is applied to the regulating blade, the toner includes, an insulating external additive and an electrically-conductive external additive, satisfies any of the following first to third conditions, the first condition: a volume average grain diameter of the electrically-conductive external additive is larger than a volume average grain diameter of the insulating external additive, the second condition: a volume average grain diameter of the electrically-conductive external additive is larger than a volume average grain diameter of the insulating external additive in which coverage in the toner is higher than that of the electrically-conductive external additive, and the third condition: coverage of the electrically-conductive external additive in the toner is higher than coverage of the insulating external additive that is larger in volume average grain diameter than the elect

Abstract: An image forming apparatus includes plural developing units separately containing a toner A and a toner B that satisfy relationships (1) and (2) and have similar colors. The toner A and the toner B each contain a binder resin containing a polyester about 90 mass % or more of the binder resin, and about 90 mass % of the binder resin of the toner A and about 90 mass % of the binder resin of the toner B are the same resin. The polyester contains an amorphous polyester having an alkyl side chain and a crystalline polyester. The relationship (1) is Ta (toner A)>Tb (toner B) in terms of flow tester ½ effluent temperature. The relationship (2) is Aa (toner A)>Ab (toner B) in terms of an amount of an aluminum (with reference to net intensity) measured with fluorescent X-ray.

Abstract: An electrostatic charge image developing toner includes a binder resin that contains an amorphous polyester resin and a colorant. The toner satisfies the following expressions: 20 ?S/cm???150 ?S/cm, and 0.01<Cm/(Cc+Co)<0.1, where ? represents the conductivity of a supernatant solution when 0.1 g of the toner is dissolved in 30 ml of tetrahydrofuran, Cm represents the content (% by mass) of metal elements Al, Mg, and Fe, Cc represents the content (% by mass) of carbon, and Co represents the content by mass) of oxygen.

Abstract: A polyester resin for a toner containing: a repeating unit derived from a dicarboxylic acid component; and a repeating unit derived from a diol component represented by Formula (1): wherein each of R1 and R2 independently represents a hydrogen atom or a methyl group, each of L1, L2 and L3 independently represents a divalent linking group selected from the group consisting of carbonyl groups, ester groups, ether groups, sulfonyl groups, substituted or unsubstituted chained alkylene groups, substituted or unsubstituted cyclic alkylene groups, substituted or unsubstituted arylene groups, and combinations thereof, L1 and L2 or L1 and L3 optionally forms a ring, and each of A1 and A2 independently represents a rosin ester group.

Abstract: A method of preparing a carrier for electrophotography, including a core material and a coating material layer formed on the surface of the core material, including: coating the core material with the coating material; and burning the coating material with a high-frequency induction heater, wherein the core material has a saturated magnetization of from 40 to 95 Am2/kg.

Abstract: A developing apparatus including a developing container for containing developer, the developing container having an opening portion, a developer carrying member for carrying the developer at the opening portion, a detecting member for detecting a developer amount, the detecting member detecting a capacitance between the developer carrying member and the detecting member, and a force receiving portion for receiving a force and moving the developing container between a first position in which a developing operation is performed by the developer carrying member and a second position in which the developing operation is not performed, wherein the capacitance can be detected in the second position, and the detecting member is a rotatable developer supplying member for supplying the developer to the developer carrying member, the developer supplying member including a foam layer in which the developer can enter.

Abstract: There is provided a toner for electrophotography containing at least a binder resin, a colorant and a barium compound, and having a relaxation modulus G(t) of from about 2.0×102 Pa to about 3.0×103 Pa in a relaxation time of t=10×Dt (wherein Dt is the heating time taken during fixing) as determined by the measurement of dynamic viscoelasticity, and a barium content of from about 0.1% to about 0.5% with respect to the total amount of constituent atoms in the toner as determined by X-ray fluorescence.

Abstract: A toner for developing an electrostatic image, includes: colored particles containing a colorant and a binder resin, and two or more kinds of inorganic particles that are externally added to a surface of the colored particles, in which the two or more kinds of inorganic particles contain titanium-containing particles and silica-containing particles, an exposure ratio of the surface of the colored particles is about 25% or less, and a ratio of the silica-containing particles that are in contact with the colored particles is about 10% by number or less.

Abstract: An image forming method including forming an electrostatic latent image on an image bearing member; developing the electrostatic latent image using a color toner and a transparent toner to form a color toner image and a transparent toner image thereon; transferring the color toner image and the transparent toner image to a recording material; and fixing the color toner image and the transparent toner image on the recording material. The color toner includes a polyester resin and a colorant, and the loss tangent of the color toner has a maximum peak at a temperature of from 80° C. to 160° C., and is not greater than 3 at the maximum peak. The transparent toner includes a crystalline polyester resin, and the loss tangent of the transparent toner has a maximum peak at a temperature of from 80° C. to 160° C., and is not less than 3 at the maximum peak.

Abstract: A toner for developing an electrostatic image, includes: colored particles containing a colorant and a binder resin, and two or more kinds of inorganic particles that are externally added to a surface of the colored particles, in which the two or more kinds of inorganic particles contain titanium-containing particles and silica-containing particles, an exposure ratio of the surface of the colored particles is about 25% or less, and a ratio of the titanium-containing particles that are in contact with the colored particles is about 15% by number or less.

Abstract: A method for producing colored resin particles including: dissolving or dispersing at least binder resin and colorant in organic solvent to prepare oil phase; dissolving resin A and basic compound in aqueous medium to prepare aqueous phase, the resin A having solubility <2.0 g/100 g water having temperature 25° C. and pH 3.0 and solubility ?2.0 g/100 g water having temperature 25° C. and pH 10.0; dispersing the oil phase in the aqueous phase to prepare core particle dispersion liquid; dispersing resin particles in aqueous medium to prepare resin particle dispersion liquid, and adding the resin particle dispersion liquid to the core particle dispersion liquid so that the resin particles are attached onto the core particles, to prepare dispersion liquid containing particles each having the core particle and the resin particles attached thereonto; removing the organic solvent from the dispersion liquid; washing the particles; and drying the particles.

Abstract: A toner set for electrostatic image development includes a cyan toner, a magenta toner, and a yellow toner, wherein the Vicat softening temperatures of the toners are respectively in the range of from about 30° C. to about 60° C., and among the toners, the difference between the Vicat softening temperature of the toner having the highest Vicat softening temperature and the Vicat softening temperature of the toner having the lowest Vicat softening temperature is from about 1° C. to about 5° C.

Abstract: An electrostatic image developing toner including: a toner particle containing a coloring agent and a binder resin; and an external additive on the toner particle, wherein the external additive contains a silica particle, a primary particle of the silica particle has an average particle diameter of from 70 nm to 400 nm, a particle size distribution index of the primary particle of from 1.0 to 1.9, and an average circularity of from 0.5 to 0.9.

Abstract: An electrostatic image developing toner including: toner particles each containing binder resin and colorant; and an external additive supported on the toner particles, wherein the toner particles each have protrusions on surface thereof, average of lengths of long sides of the protrusions is 0.10 ?m or more but less than 0.50 ?m, standard deviation of the lengths of the long sides of the protrusions is 0.20 or less, coverage rate of the protrusions on the surface of each toner particle is 30% to 90%, the external additive includes at least two different particles including external additive (A) and one or more external additives (B), external additive (A) has longest average primary particle diameter among the external additives and charged to have the opposite polarity to the toner particles, and at least one of the external additives (B) is charged to have the same polarity as the toner particles.

Abstract: A toner is provided including a core particle comprising a binder resin, a colorant, and a release agent, and a shell layer comprising particles of a vinyl resin. The vinyl resin comprises 80% by weight or more of a unit of an aromatic compound having a vinyl-polymerizable functional group. A method of manufacturing the above toner is also provided, including steps of dissolving or dispersing the binder resin, the colorant, and the release agent in an organic solvent to prepare an oily liquid, dispersing the oily liquid in an aqueous medium to prepare the core particles, and adhering particles of a vinyl resin to the surfaces of the core particles to form shell layers.

Abstract: A toner set for electrostatic image development, includes: at least one kind of a colored toner that contains a coloring agent; and a transparent toner that does not substantially contain a coloring agent, wherein a proportion of particles having a shape factor of 0.94 or less in mother particles of the transparent toner is about 5% by number or less based on particles having a particle diameter of 7.5 to 15 ?m, and a reflectance of the mother particles of the transparent toner is about 90% or more for light at a wavelength of 700 nm.

Abstract: An electrostatic image developing toner including: a toner particle containing a coloring agent and a binder resin; and an external additive having a volume average particle diameter of from 70 nm to 400 nm, an average circularity of from 0.5 to 0.9 and a standard deviation of circularity of not more than 0.2.

Abstract: A particle producing method is provided including bringing a material into contact with a compressible fluid to prepare a melt of the material, and discharging the melt from a vibrated through hole to form particles of the melt. A particle producing apparatus is also provided including a discharger to discharge the melt. The discharger includes a storage to store the melt, at least one through hole disposed on the storage, and a vibrator to vibrate the through hole. The particle producing apparatus further includes a particle forming member defining a space within which the discharged melt is formed into particles and a pressure controller controlling a pressure difference between the space and an inside of the storage so that the discharged melt is formed into a columnar melt and the columnar melt is constricted and separated into particles.

Abstract: A toner including a binder resin, a colorant and protruding portions on a surface of the toner, wherein the average length of long sides of the protruding portions is 0.1 ?m or greater, but less than 0.5 ?m, wherein the standard deviation of the lengths of the long sides of the protruding portions is 0.2 or less, and wherein the protruding portions have a coverage of 30% to 90%.

Abstract: A toner, has a number mode diameter of 3 ?m or more and 6 ?m or lower and a particle size distribution of a toner including an externally-applied agent in the range of 0.6 ?m to 400 ?m in which the number frequency of a toner smaller than the number mode diameter is smaller than the number frequency of a toner equal to or larger than the number mode diameter.

Abstract: A method for determining a location on an image bearing surface of an image printing system where a toner image is to be printed is provided. The method comprises generating a first signal from a detector that is configured to detect a reference mark on the image bearing surface, and a second signal from a clock system that counts incremental movements of the image bearing surface, determining a first value that correlates the first signal and the second signal, where the first value corresponds to a value of the second signal at a start of characterization of the image bearing surface, and determining a second value using the first value, where the second value provides the location on the image bearing surface where the toner image is to be printed.

Abstract: A carrier for a two-component developer, includes: magnetic particles and a resin coating layer that is coated on the magnetic particles, the resin coating layer containing metal nitride particles having a volume average primary particle diameter of from about 300 to about 2,000 nm.

Abstract: A developing apparatus for developing a latent image formed on an image bearing member with a developer includes a first developer carrying member for carrying and feeding the developer by rotation thereof about a rotation axis which is at a fixed position; a second developer carrying member for carrying and feeding the developer by rotation thereof, the second developer carrying member having a rotation axis which is swingable relative to the first developer carrying member; a supporting member for supporting the second developer carrying member swingably about the first developer carrying member; a driving device for applying a driving force to the first developer carrying member; and a driving belt for transmitting the driving force applied to the first developer carrying member to the second developer carrying member.

Abstract: A toner for developing an electrostatic charge image includes a core layer including a first binder resin, a colorant and a releasing agent; and a shell layer coating the core layer and including a second binder resin. The first binder resin of the core layer includes a low molecular weight amorphous polyester resin having a weight-average molecular weight of about 6000 g/mol to about 20000 g/mol, a high molecular weight amorphous polyester resin having a weight-average molecular weight of about 25000 g/mol to about 100000 g/mol, and a crystalline polyester resin having a weight-average molecular weight of about 8000 g/mol to about 30000 g/mol. The second binder resin of the shell layer includes the low and high molecular weight amorphous polyester resins.

Abstract: A housing of a developing apparatus is provided with a conveying member in a developer supplying and recovering portion, and with two agitating members rotating from the below to the above in portions opposed to each other in a developer agitating portion. A guide is provided in an inner bottom surface of the housing between two agitating members. A braking portion suppressing a discharge of a developer is provided in a downstream side of the developer agitating portion in a developer conveying direction of the second agitating member, and a discharge portion is provided in a downstream side of a disc of the braking portion.

Abstract: A housing of a developing apparatus is provided with a conveying member in a developer supplying and recovering portion, and two agitating members rotating in the same direction respectively as viewing rotating shafts from a near side in an axial direction, in a developer agitating portion. A guide is provided in an inner bottom surface of the housing between two agitating members. A braking portion suppressing a discharge of a developer is provided in a downstream side of the developer agitating portion in a developer conveying direction of the second agitating member, and a discharge portion is provided in a downstream side of a disc of the braking portion.

Abstract: A housing of a developing apparatus is provided with a conveying member in a developer supplying and recovering portion, and two agitating members rotating in the same direction respectively as viewing rotating shafts from a near side in an axial direction, in a developer agitating portion. A guide is provided in an inner bottom surface of the housing between two agitating members. A braking portion suppressing a discharge of a developer is provided in a downstream side of the developer agitating portion in a developer conveying direction of the first agitating member, and a discharge portion is provided in a downstream side of a disc of the braking portion.

Abstract: The electrostatic charge image developing toner includes a colorant containing rutile type and anatase type titanium oxides, and a binder resin.

Abstract: Provided is a magenta toner containing toner particles that contain a colorant and a binder resin, wherein the colorant contains C.I. Pigment Red 57:1 and C.I. Pigment Yellow 180, a mass ratio between the C.I. Pigment Red 57:1 and the C.I. Pigment Yellow 180 being 99:1 to 10000:1, and wherein the binder resin contains a polyester resin that has a repeating unit derived from bisphenol A ethylene oxide represented by formula (1): wherein each of m and n independently represents an integer of 2 to 4.

Abstract: A magenta toner includes a binder resin containing a polyester resin having a dodecenylsuccinic acid structure as a constituent unit, and a solid solution of C.I. Pigment Violet 19 and C.I. Pigment Red 122, the magenta toner having an amount of the solid solution of from 2% by mass to 30% by mass based on the total mass of the toner.