Electron source drive device employing an improvement of an electron source unit.

摘要

In an electron source drive device, a cathode support member arranged in contact with a cathode is constructed by a conductive member and an insulation member interposed between the conductive member and a contacting portion of the cathode, and the insulation member is made of a material having a resistivity and a specific dielectric constant such that the electric discharge time constant of electrons on the surface of the insulation member depending on the insulation resistance and the electrostatic capacity between the surface of the insulation member and the conductive member is set in a visually permissible range of not too much in excess of one cycle of emission of the cyclical electron from the cathode without bringing forth intermittent electron emission. <IMAGE>