IMAGE INTENSIFYING DEVICE WHICH EXERCISE GATE FUNCTION

PURPOSE:To make it possible to exercise a high-speed gate function securely, by composing the system of an image intensifying tube, a power source device, a pair of semiconductor switches, and a signal applying means. CONSTITUTION:A common terminal of a bias shift switch 18 is connected to a terminal 18a. And the voltage VA of a photoelectric cathode 10 is -(V5 + V6). The voltage VB of the incident surface 12a of a microchannel plate is -(V4 + V5 + V6), and the voltage of the photoelectric cathode 10 is lower by the V4, being at an inverse bias. Then, a voltage V18 is applied to the base of an avalanche transistor (TR) 16 at the point of time T1, while a voltage V19 is applied to the base of a TR 17 at the point of time T2. The voltage VA of the cathode 10 when the TR 16 is ON, is -(V3 + V5 + V6 + V7). After that, the voltage V19 is applied to the base of the TR 17 at the point of time T2. The voltage VB of the incident surface 12a, when the TR 17 is ON, drops to -(V3 + V4 + V5 + V6 + V7). Therefore, in the period from the T1 to T2, VB-VA comes to be positive, and the gate of the image intensifying tube 1 is formed to be an opening condition for a short time.