Abstract: A makeup fluid is added to an ink liquid of an inkjet printer to reduce the viscosity of the ink liquid, the makeup fluid including a fluorescent color material in a solvent. An inkjet printer apparatus employing a makeup fluid is provided with a makeup fluid tank to which a light-emitting element and a light-receiving element are attached, and detects the presence or absence of the makeup fluid by irradiating ultraviolet light from the light-emitting element, causing visible light to be emitted from the fluorescent color material in the makeup fluid, and detecting the visible light with the light-receiving element.

Abstract: The present invention addresses the problem of enabling a charge control-type inkjet printer to enable real-time control during an operation and to maintain optimal printing conditions while operating. This charge control-type inkjet printer is provided with: a printing head including a nozzle unit for discharging ink; a pressure reduction valve for adjusting the pressure of the ink to be supplied to the nozzle unit of the printing head; and an ink container for accommodating the ink to be supplied to the nozzle unit of the printing head, wherein an imaging unit is further provided which images an image of ink that is discharged from the nozzle unit and is in a particulate state.

Abstract: A makeup fluid is added to an ink liquid of an inkjet printer to reduce the viscosity of the ink liquid, the makeup fluid including a fluorescent color material in a solvent. An inkjet printer apparatus employing a makeup fluid is provided with a makeup fluid tank to which a light-emitting element and a light-receiving element are attached, and detects the presence or absence of the makeup fluid by irradiating ultraviolet light from the light-emitting element, causing visible light to be emitted from the fluorescent color material in the makeup fluid, and detecting the visible light with the light-receiving element.

Abstract: The present invention addresses the problem of enabling a charge control-type inkjet printer to enable real-time control during an operation and to maintain optimal printing conditions while operating. This charge control-type inkjet printer is provided with: a printing head including a nozzle unit for discharging ink; a pressure reduction valve for adjusting the pressure of the ink to be supplied to the nozzle unit of the printing head; and an ink container for accommodating the ink to be supplied to the nozzle unit of the printing head, wherein an imaging unit is further provided which images an image of ink that is discharged from the nozzle unit and is in a particulate state.