Characteristics of experimental CdSe vidicons

A high sensitivity vidicon using a CdSe photoconductive target was successfully developed. A new CdSe target with junction-type structure was employed to realize the improved characteristics as given below. The sensitivity is about 20 times higher than that of conventional vidicons, which makes it possible to operate the tube with low levels of faceplate illumination of 0.1-1 lx. A typical sensitivity is 200 nA/0.5 lx with scanning areas of 9.5 × 12.7 mm². The gamma of the light transfer characteristic is 0.9. The tube provides a wide spectral response over the whole range of visible wavelengths. The dark current is less than 1 nA. The lag is 10 percent for a 200-nA signal current. High resolution is achieved. Afterimage and burn-in are hardly observed under normal operational conditions. The life of the tube extends to more than 1000 hours. With these characteristics, the CdSe vidicon can produce suitable pictures with good quality both for industrial use and for broadcasting use. The detailed structure of the target is also discussed.