The emission response of ultraviolet-excited ZnS to stimulating infrared radiation of 1.5 to 5.5 micron wavelengths was studied at 77 degrees Kelvin. An image of an infrared source converted to visible light by a ZnS phosphor plate was photographed. The emission spectrum of ZnS under infrared stimulation at 2.46 microns was also examined. An energy band model for ZnS based on the infrared response curve and the emission spectrum is proposed. The feasibility of using ZnS in an imaging infrared detector is further enhanced by this study.