Experimental Study of Slow-Scan High-Resolution Video Transmission at One-MegaHertz Bandwidth

It is often desirable to transmit graphic information such as a typewritten page or a detailed photograph over band-limited transmission media and to display it at the receiving end on a real-time basis. Since a narrow bandwidth is desirable for this, the video information must be transmitted at a low frame rate. At the receiving station a cathode-ray tube may be used to display the slow-scan information. To overcome flicker resulting from the low frame rate and/or inefficient long persistent phosphors a scan-conversion and frame-repeating technique is described in this paper. At the receiver the transmitted information displayed on a slow-scan cathode-ray tube is optically transferred through a lens to the target of a storage vidicon working at fast-scan rates. A long decay characteristic of stored charge in the photoconductor of the target makes it possible to regenerate the same frame of the video signal many times at the fast-scan rates without conspicuous fading during the slow-scan frame time. The regenerated information is displayed on a high-resolution wideband monitor.

Print ISSN

0361-4573

Published

1968-12

Content type

Original Research

DOI

10.5594/J10892