1. Image conversion and enhancement process:
(1) The input screen converts the received X-ray image into a visible light image and converts it into an electronic image from the photocathode of the input screen.
(2) Photoelectrons focus, accelerate, and impinge under the action of an electron lens formed by a cathode potential, a focus electrode potential, and an anode potential, and form an electronic image that is reduced, inverted, and enhanced (increased electron density) on the output screen.
(3) The electronic image is converted into a visible light image by the output screen. The higher the anode potential, the faster the movement speed of photoelectrons, the greater the kinetic energy when striking the output screen, the more electrons are excited, and the higher the brightness of the output screen.
2. Brightness Gain: The main purpose of the image intensifier tube is to increase the brightness of the image for camera photography. The ratio of the brightness of the output screen to the brightness of the input screen image is defined as the brightness gain of the image intensifier tube.