CRT with compensating focussing system - uses variable-power lens after accelerating electrode to keep focus constant despite beam energy changes (CS 30.4.79)

摘要

The c.r.t. has its focussing system provided with a variable lens(11) between the accelerating electrode(6) and the second focussing electrode(8) in order to ensure that the electron beam's focussing at the screen remains constant. This lens has a variable power to keep focussing constant despite changes in the beam's energy. The focussing system's two electrodes are connected together by a resistive material to generate a distributed electric field.