Abstract

In Isocon scan of an image-orthicon type camera tube, the video signal is derived from those electrons in the scanning beam which are scattered at the storage target. Using suitable electron optics, these scattered electrons may be collected and amplified in the electron multiplier along with only a small fraction of unmodulated return beam electrons. In contrast, the output signal obtained with orthicon scan contains a large unmodulated current. Isocon scan introduces much less noise than orthicon scan and extends the useful range to lower illumination levels. The dynamic range of light levels in a single scene that may be handled by an Image Isocon may be an order of magnitude greater than with conventional image orthicons. A dual-mode camera tube capable of operation either with orthicon scan or with Isocon scan is described. A signal-to-noise analysis is presented for both types of scan. The results of the measured performance compare favorably with that predicted by the analysis.

© 1963 Optical Society of America

Image Orthicon Astronomy at the Dearborn Observatory

William T. Powers and Richard S. Aikens
Appl. Opt. 2(2) 157-163 (1963)

Astronomical Image-Integration System Using a Television Camera Tube

E. Luedicke, A. D. Cope, and L. E. Flory
Appl. Opt. 3(6) 677-688 (1964)

Problem of Infrared Television-Camera Tubes vs Infrared Scanners

J. A. Hall
Appl. Opt. 10(4) 838-844 (1971)

The Detectivity of Electron Beam Scanning Types of Image Tubes

S. Nudelman
Appl. Opt. 6(1) 149-157 (1967)

Low Light Level TV Techniques

J. Gildea
Appl. Opt. 9(10) 2230-2235 (1970)