1.06 Micron Mosaic Vidicon.
Final technical rept. 1 Dec 68-30 Nov 70,
HUGHES RESEARCH LABS MALIBU CA
Pagination or Media Count:
The feasibility of using a silicon phototransistor mosaic array as a vidicon target was established. An analysis of device operation indicated that although phototransistor signal gain can be obtained during both the read and write parts of elemental duty cycle, the maximum effective gain is secured by maximizing the read gain. Expressions for read and write gain in terms of the transistor parameters have been derived, and the effect of phototransistor operation on vidicon sensitivity, image persistance lag, and dynamic range have been considered. Several types of phototransistor arrays have been fabricated and tested. Initial efforts, aimed at the development of single window devices were abandoned when it became apparent that it was inherently difficult to get signal gain at low current levels in this structure. Subsequent efforts on more conventional planar phototransistor arrays resulted in the first successful demonstration of phototransistor signal gain under the usual conditions of vidicon operation. Signal gains of at least thirty were recorded. A passivated mesa phototransistor structure was then designed to increase the packing density of the array and the resolution of the camera tube. Arrays of 1000 phototransistorsin. were made using this approach. No low light level signal gain was measured for any of these arrays. Author
- Non-Radio Communications