High-resolution MS-type Saticon pick-up tube with optimized electron optical properties

摘要

Abstract: In order to develop image pick-up tubes with high and uniform resolution over a large image size, the electron optical design consisting of magnetic focusing and electrostatic deflection (MS-type) was investigated and optimized by 3-dimensional numerical calculations. With optimal electromagnetic configuration, the calculated intensity distribution of the beam spot in the focal plane showed a circular shape of nearly constant width even for elongations of the beam far from the image axis, which promises negligible image aberrations. Test tubes of 1 in. format were built up using Saticon photoconductive layer and low output capacitance (LOC). The overall length of the pick-up tube is less than 125 mm. Experimental investigations resulted in a modulation depth (square wave response) of 60% and more at 1600 TVL using an image size of 19 mm diameter (interlaced system, 1249 lines). The uniformity of resolution at the whole image area was confirmed in agreement with theory. An analysis of image aberrations showed very small curvature of field, landing error, astigmatism and geometric distortion. In comparison to conventional all magnetic tubes (MM-type), the MS- type tube yields superior image quality especially at the corners, more flexibility for using different scanning modes and a reduction in power consumption of the tube and in total costs for the camera system.!