An Experimental Visual Communication System

Facilities for the transmission of visual material by facsimile have been offered to the public for over 30 years. Even so, facsimile has not become a very widely used service. In contrast, the post-war development of broadcast television has excited much interest in the use of television as a means for transmitting visual material. Industrial television equipment has been developed and sold for all sorts of applications. However, there is increasing awareness t h a t television may not be the most suitable and least expensive way of filling some of the needs for visual communication for which its use has been suggested. Television as a private visual communication means is attractive from many points of view. Much of the terminal equipment is similar or identical to t h a t developed for broadcast purposes. Consequently, the costs of terminal equipment can be kept low through the benefits of mass production for broadcasting. In m a n y installations the receiving terminal may be nothing more than a standard broadcast receiver. This has the added advantage t h a t little training is required for operation of the receiver. On the other hand, transmission of television signals produced under 141