Cup-shaped control electrode in CRT - has cathode mounted in insulating ring held by metal sleeve in control electrode cavity

摘要

The CRT has a cathode unit which has an annular insulator in whose hole the cathode element is placed. It is mounted by its periphery at one end of a metal sleeve. This sleeve is inserted into the hollow of the control electrode. Its other end is fastened to the control electrode open end. The control electrode (1) is made of a metal whose thermal coefficient of expansion is equal to or smaller than that of the metal sleeve (2). The heating element (6) is in the form of a coil.