What is the primary function of the electron gun in a TV camera tube?

The primary function of the electron gun in a TV camera tube is to produce the electron beam. The electron gun generates a stream of electrons by heating a cathode, which then releases electrons through thermionic emission. This stream of electrons is crucial for creating the images captured by the TV camera, as it is these electrons that will eventually interact with phosphorescent materials to display the image on a screen.

The electron gun also plays a significant role in the initial formation of the beam, setting the stage for the subsequent processes of accelerating, deflecting, and focusing the beam to ensure that it accurately scans the image in a controlled manner. The production of the electron beam is fundamentally the first step in the operation of the TV camera tube, enabling all other functions to take place.