SOLID STATE IMAGE INTENSIFIERS PhaseⅡ Development of an Internal Trainer Optical System Image Intensifiers

摘要

The objective of the program was the development of photoconductor-electroluminescent (PC-EL) type solid state image intensifier panels for the visible light band (Phase l), and the building of an optical train (bench), incorporating the intensifier panels and the necessary power supplies (Phase 11). Regarding Phase I, the work was divided into two directions: (l) building a low resolution (40 lines per inch) image intensifier panel; (2) building a high resolution (1000 lines per inch) image intensifier panel.nThree different and new construction methods were developed in building the low resolution image intensifier panel: (l) Fotoform substrate construction; (2) grooved glass construction with wire electrodes; (3) sandwich construction. The easiest solution with the available materials was the Fotoform construction, but it had to be discontinued because of the limitation in resolution. The grooved glass construction presented many technological difficulties. The sandwich construction, after the difficulties had been solved, proved to be a superior solution because of its simplicity and inherent higher resolution. Image intensifier panels have been built in sizes up to 6" x 6", with maximum standard luminous gains (2870 K light source) of 100 ft-L per ft-c, with maximum output brightness of 30 ft-L, and with resolution higher than 100 lines per inch. For achieving the above results, a large effort was spent on the development of the PC and EL layers which offered the appropriate characteristics.nRegarding the high resolution image intensifier, a major effort has been spent in developing an evaporated EL film, indispensable for this construction. Working image intensifiers in this construction have not been built yet.nAlthough the developed sandwich type image intensifier panel could be considered as an important achievement, there are some characteristics, such as the speed and the gain (primarily for the shorter wavelengths) which should be improved for meeting the requirements. The limitations are connected mostly to the PC characteristics. Therefore, it is recommended to spend a major effort for the development of improved photoconductive materials. It is proposed further more to spend a moderate effort for the building of high resolution image intensifiers and toward protection of the panels from humidity and corrosive atmosphere.