ERIC Number: ED196427
Record Type: Non-Journal
Publication Date: 1978-May
Reference Count: N/A
Visual Systems for Teleconferencing: Telewriting, Televideo, and Facsimile.
Telewriting, televideo, and facsimile systems are new forms of teleconferencing which can transmit a variety of graphic and pictorial information on voice-grade telephone lines. All of the equipment employs solid-state circuitry to enhance performance and to exploit the limitations of a narrowband channel. Telewriters range from simple electro-mechanical pens through complex computer graphics systems. All forms generate graphic or written information. Slow scan televideo systems, which add the capacity to present pictorial information, transmit the picture over regular telephone lines or FM radio channels for display on a television monitor. The facsimile system, which can transmit documents over long distances within a few minutes, requires a transmitter and a receiver (or two transceivers) to convert the printed document into electrical signals to be sent over telephone lines. Such advancements in electronic technology as miniaturization of integrated circuitry for processors, dense memory chips capable of greater bit-packing, charge-coupled devices to increase storage capacity, and fast multiplier chips for more complex signal operations are chiefly responsible for improvements in these systems. As data compression becomes feasible, the total number of bits transmitted can be reduced to improve the image quality over a voice-grade telephone line. Tables and graphs are included. (BK)
Descriptors: Broadcast Reception Equipment, Comparative Analysis, Computer Graphics, Data Processing, Evaluation Criteria, Facsimile Transmission, Technological Advancement, Teleconferencing, Television
Center for Interactive Programs, University of Wisconsin-Extension, 975 Observatory Drive, Madison, WI 53706 ($15.00).
Publication Type: Information Analyses
Education Level: N/A
Authoring Institution: Wisconsin Univ., Madison. Univ. Extension.