A Camera Tube with a Silicon Diode Array Target

Abstract

A variety of electronic cameras have been developed for television systems.1Among these the vidicon2and the Plumbicon3have the inherent advantages of high sensitivity, small size, and simple mechanical construction. The operating principles of the vidicon and the Plumbicon are quite similar since they both utilize a thin photoconductive layer to convert the optical image to a stored charge pattern which is periodically scanned and erased by an electron beam. Erasing the charge pattern creates the video signal. However, there is a distinct difference in overall device performance since the photoconducting target in the Plumbicon (PbO) is deposited in a manner to form a single, large area, graded p-n junction, each layer having high resistivity. In the vidicon, the evaporated layers of Sb2S3forming the target behave like a semi-insulating photoconductor.