PURPOSE: To check generation of an excessive pseudo-signal even when a return beam flows into a getter vacuum evaporation film by connecting a conductive getter vacuum evaporation film with a deflection electrode or a terminal to which the prescribed potential is to be given for being held in proper potential.
CONSTITUTION: One of four conductive films 4 for deflection electrodes is provided with the extended part 16 projecting toward a getter vaccum evaporation film 15 while forming the getter vacuum evaporation film 15 partly overlapping said extended part 16 by getter flash. And generally voltage of about 300±60V is impressed on the conductive film 4 for a deflection electrode so that the getter vacuum evaporation film 15 is held about in said potential. Thereby, the greater part of the return beam going to the side of the getter vacuum evaporation film 15 is absorbed by the getter vacuum evaporation film 15 while reducing a reflection beam and suppressing generation of a pseudo-signal.
KAMIMURA TAKEHIRO
FUJIWARA SHINYA
