Abstract
This chapter deals with the physics and engineering aspects of both of the devices, which are at the heart of the many displays and display issues. The limitations to its applicability are controlled only by the density of detector elements on the retina and by its inherent aberrations. A portion of this limitation can be subdued with the assistance of instruments such as binoculars or a telescope by increasing the angular magnification but at the expense of the total viewing angle. Direct-view electronic image intensifiers can be used to rectify the problems that otherwise plague devices such as a binocular by accumulating a larger fraction of the available photons, using these more effectively. A single-stage image intensifier tube consists of an image sensor, an electron lens, a phosphor screen. The simplest version of an image tube is referred to as either biplanar or proximity focused. An objective lens collects the scene information and focuses onto the photo-cathode of the tube.