Indirectly heated cathode for CRT - has insulating support carrying heating filament, surrounding sleeve and emitter

摘要

The indirectly heated cathode is supported by an insulating support and has a heating filament, partly surrounded by a sleeve, and an emitter. All these elements are independently mounted on the insulating support (1). The sleeve (2) surrounding the heating filament (5) has an aperture, through which the emitter (7) can be heated by radiation, being mounted in front of this aperture. Preferably the insulating part is disc-shaped and has protrusions and/or recesses for retention of the cathode parts. The heating filament surrounding sleeve may be in the form of a hollow cylinder whose one open end is secured to the insulating support, the emitter being mounted at a small distance from the other open end of the sleeve.