Some aspects of vidicon performance

The performance of the 1-in. vidicon is discussed, particularly the effect of various operating conditions on transfer characteristics, lag, resolution and geometry. When target voltage and dark current are high, maximum sensitivity is obtained, but this is at the expense of the other parameters. In the E.M.I. vidicon, the optimum performance as regards ¿ and lag is obtained for signal currents of 0.2 to 0.3 ¿A and dark currents of 0.01 to 0.03 ¿A. Methods of measuring sensitivity, ¿ and lag are described and possibe sources of error indicated. The effect of bias illumination on ¿, lag and resolution is analysed. Improvements in geometry are described together with a method of improving resolution. Infrared and ultra-violet sensitive tubes are mentioned.