An image forming apparatus includes a developing unit, a transferring unit, and a fixing unit. The developing unit performs an attachment process in which the developing unit attaches a luminescent toner to a latent image that is formed on a basis of image data. The transferring unit performs a transfer process in which the transferring unit transfers, onto a medium, the luminescent toner attached to the latent image. The fixing unit performs a fixing process in which the fixing unit fixes, to the medium, the luminescent toner transferred onto the medium. The attachment process performed by the developing unit and the transfer process performed by the transferring unit are each performed plural times for the medium, on the basis of the image data.

A reversibly allochroic toner contains a binder resin and a colorant. The colorant reversibly switches between first and second color states in response to temperature changes. The colorant exhibits a hysteresis in a temperature-color state curve thereof in which the following relationships are satisfied.

Tr<T.sub.L2<T.sub.L1<T.sub.H1<T.sub.H2<Tg

T.sub.H250 C.

20 C.Tr30 C. where, T.sub.H1 is a temperature at which the colorant starts to change from the first color state to the second color state, T.sub.H2 is a temperature at which the colorant completely changes to the second color state, T.sub.L1 is a temperature at which the colorant starts to change from the second color state to the first color state, T.sub.L2 is a temperature at which the colorant completely changes to the first color state, and Tg is a glass transition temperature of the binder resin.

A fluorescent green toner includes toner particles including a fluorescent yellow dye Sy, a peak wavelength of a spectral reflectance of the fluorescent yellow dye Sy being at 500 nm or more and 550 nm or less, a yellow pigment Py, and at least one pigment Pgc selected from the group consisting of a green pigment and a cyan pigment, wherein CSy/(CPy+CPgc) is 0.01 or more and 0.3 or less, and (CSy+CPy)/CPgc is 0.3 or more and 1.5 or less, where CSy, CPy, and CPgc represent contents of the fluorescent yellow dye Sy, the yellow pigment Py, and the pigment Pgc in the toner particles, respectively.

A method of producing an emissive toner composition including selecting a photoluminescent agent, a charge control agent, and one or more additives and combining the photoluminescent agent, charge control agent, and one or more additives to form an emissive toner composition that when printed to produce an image component on a substrate, the emission spectra of the image component for irradiation with a first excitation energy includes only dominant emission peaks corresponding to one or more dominant emission peaks of the photoluminescent agent. The photoluminescent agent is selected such that it emits light having one or more dominant emission peaks in a first emission spectral region when irradiated with the first excitation energy. The charge control agent and one or more additives are selected such that they do not emit light in the visible spectrum when irradiated with visible light and does not emit light in the first emission spectral region when irradiated with the first excitation energy.

A developer according to an embodiment includes a toner having a color erasable by heating and a carrier. The carrier includes a core portion and a coating portion covering at least 50% of the core portion. The coating portion includes a white-colored additive agent which suppresses an increase in electrification due to friction between the toner and the carrier, a mass of the additive agent being between 20% and 60% of a total mass of the coating portion.

A method for producing a developing agent including preparing a dispersion liquid containing first fine particles containing a binder resin and second fine particles containing a color developable compound, a color coupler, and a color eraser, and aggregating the first and second fine particles in the dispersion liquid to form aggregated particles.

Disclosed is a decolorizable electrophotographic toner, including: a binder resin; and a colorant which contains at least a color developable compound and a color developing agent and is covered with an outer shell so as to have a capsule structure, wherein the number ratio of particles having an equivalent circle diameter of 0.6 m or more and 2.5 m or less of the toner when measured using a flow particle image analyzer after the toner is dispersed in an aqueous medium at a ratio of 0.08% by weight and the resulting dispersion is subjected to a stirring treatment in which stirring is performed at 5000 rpm for 30 minutes using a homogenizer (T-25 digital ULTRA-TURRAX (manufactured by IKA Japan K.K., provided with a shaft generator S25N-10G)) is 30% by number or less.

A method of producing an emissive toner composition including selecting a photoluminescent agent, a charge control agent, and one or more additives and combining the photoluminescent agent, charge control agent, and one or more additives to form an emissive toner composition that when printed to produce an image component on a substrate, the emission spectra of the image component for irradiation with a first excitation energy includes only dominant emission peaks corresponding to one or more dominant emission peaks of the photoluminescent agent. The photoluminescent agent is selected such that it emits light having one or more dominant emission peaks in a first emission spectral region when irradiated with the first excitation energy. The charge control agent and one or more additives are selected such that they do not emit light in the visible spectrum when irradiated with visible light and does not emit light in the first emission spectral region when irradiated with the first excitation energy.

A method of producing an emissive toner composition including selecting a photoluminescent agent, a charge control agent, and one or more additives and combining the photoluminescent agent, charge control agent, and one or more additives to form an emissive toner composition that when printed to produce an image component on a substrate, the emission spectra of the image component for irradiation with a first excitation energy includes only dominant emission peaks corresponding to one or more dominant emission peaks of the photoluminescent agent. The photoluminescent agent is selected such that it emits light having one or more dominant emission peaks in a first emission spectral region when irradiated with the first excitation energy. The charge control agent and one or more additives are selected such that they do not emit light in the visible spectrum when irradiated with visible light and does not emit light in the first emission spectral region when irradiated with the first excitation energy.

A developer according to an embodiment includes a toner having a color erasable by heating and a carrier. The carrier includes a core portion and a coating portion covering at least 50% of the core portion. The coating portion includes a white-colored additive agent which suppresses an increase in electrification due to friction between the toner and the carrier, a mass of the additive agent being between 20% and 60% of a total mass of the coating portion.