An image forming apparatus includes a rotatable image carrier that carries an image; a charging unit that includes a rotatable charging member that charges the image carrier; a developing unit that supplies developer to the image carrier that is charged, the developer containing at least toner and a carrier, an external additive being added to the toner; a transfer unit that includes a transfer member that transfers the image formed on the image carrier to a transfer material; and a cleaning unit that cleans a surface of the image carrier. In the image forming apparatus, during image non-formation, the external additive is supplied to the image carrier that rotates, and the image carrier and at least the transfer member are separated from each other.

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.

Example implementations provide a method of controlling an ink developer used in electro-photography; the method comprising, following cessation of printing, varying a plurality of voltages associated with movement of ink within the ink developer at temporally disparate times.

Example implementations provide a method of controlling an ink developer used in electro-photography; the method comprising, following cessation of printing, varying a plurality of voltages associated with movement of ink within the ink developer at temporally disparate times.

An image forming apparatus includes a rotatable image carrier that carries an image; a charging unit that includes a rotatable charging member that charges the image carrier; a developing unit that supplies developer to the image carrier that is charged, the developer containing at least toner and a carrier, an external additive being added to the toner; a transfer unit that includes a transfer member that transfers the image formed on the image carrier to a transfer material; and a cleaning unit that cleans a surface of the image carrier. In the image forming apparatus, during image non-formation, the external additive is supplied to the image carrier that rotates, and the image carrier and at least the transfer member are separated from each other.

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 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.