Applications of the Pyroelectric Vidicon

Pyroelectric vidicons (PEV) are low-cost, infrared TV camera tubes which operate at room temperature. They image in any wavelength band within the 2-400 /.1M range. For the 8-14 band, the PEV has a typical Minimum Resolvable Temperature (MRT) of less than 1C at 250 TVL. When operated with increased pedestal current, the MRT can be reduced to 0.6C at 250 TVL. This paper reviews the significant parameters of the PEV, viz., electron-beam discharge lag, sensitivity, and thermal spread in the target, and some applications. These include fire location (specifically, forest fire mapping), security, industrial uses, and medical diagnostics. Forest fire mapping has been cooperatively done by Philips Laboratories and the Canadian Forestry Service. During that exercise, local sources of burning totally obscured by smoke were readily located by the PEV system. The unique ability of the PEV to detect motion lends itself to security applications. A chopping and storage mode of operation has been developed for industrial and medical applications. With this technique, the integrated signal from several frames can be displayed as a static image. Images of a circuit board show components operating at elevated temperatures. Veinal structures in various parts of the human body have been easily imaged with this system.