Image intensifier with localised brightness regulation - has photocathode producing localised disturbance in potential when excess electrons are emitted

摘要

In the image intensifier, electronic images are generated from a beam, and localised brightness of the electronic images is regulated. The photocathode (14) is designed such that if the number of electrons emitted from any section is too high, it will produce localised disturbance in the potential. There is a focusing anode (16) and a filter for the electrons not properly focused. The cathode has a high enough resistance to disturb the potential in the proper manner. The filter consists of a screen with a small opening.