Deflection system for vidicon camera - has two focal points and focussing field one-and-half times longer than effective deflection field

摘要

The deflection system, for a vidicon camera tube, produces a first focal point inside the deflection field at a point where the electron beam has already experienced some considerable deflection, and there is a second focal point in the plane of the signal plates. The focussing field has an effective length that extends up to the signal plates and is somewhat longer than 1.5 times the effective length of the deflection field where effective length is taken to mean the length of a constant field that has the same effect on the electron beam. Both deflection and focussing fields are magnetic.