High-speed, long-distance facsimile system

• Publisher: Elsevier Science
• Year: 1951
• Tongue: English
• Weight: 82 KB
• Volume: 251
• Category: Article
• ISSN: 0016-0032
• DOI: 10.1016/0016-0032(51)90505-4

✦ Synopsis

High-Speed, Long-Distance Facsimile System.--A test model of a new high-speed, long-distance facsimile system, developed by RCA Laboratories, Princeton, N. J., under contract with the Atomic Energy Commission, has been installed at the Oak Ridge National Laboratory for providing full reference library service to outlying research laboratories.

The new system incorporates several innovations in the field of facsimile reproduction. The reader-transmitter will scan printed copy or drawings on flat surfaces such as book pages and will make direct enlargements of material in small type by any ratio up to 4 to 1. The copy bed can handle individual sheets or books up to 3 in. thick. The signal is transmitted over an ordinary telephone line and the recorder will reproduce clear, highly legible black-on-white copy at a speed of 15 linear inches or 120 square inches per minute.

Operational tests to be started at Oak Ridge immediately will indicate to what extent existing library services at the Laboratory can be expanded without greatly increasing the outlay for new books and particularly scarce and expensive sets of bound scientific periodicals. The system will also prevent possible contamination of books and journals in laboratories using radioactive materials.

At the present time at Oak Ridge more than a score of separate research and production facilities scattered over a wide area require library services. If the new facsimile service proves useful, it may be possible to consolidate many of these library services into larger, more adequate units.

The transmitter is located at the central library at the X-10 site while the only operating recorder is located 8 miles away at the Y-12 site. On the initial test of the system a research chemist at Y-12 requested the complete text of a 2-page article to which he had found a reference in Chemical Abstracts. The bound periodical was located in the X-10 library stacks, placed in the transmitter, and a facsimile copy was delivered at Y-12 within 4½ min. after the request was made.

A cathode ray flying-spot scanner at the sending unit is the most important innovation. The 5-in. cathode ray tube directs a tiny spot of light through a focusing lens to "read" the copy in a thin line from left to right. The reflected light from the copy is picked up by a bank of four photomultiplier tubes which convert the varying light impulses into normal electrical facsimile signals.

The copy bed automatically moves the copy forward under the flying-spot cathode ray tube. The length of the scanning line on the copy can be adjusted from 2~-~ to 8½ in. by simply turning a knob. This automatically adjusts the lens to maintain the proper focus and the same adjustment changes the speed of the copy bed to maintain the correct scale.

The receiver, or recorder, also incorporates several new mechanical and chemical features to simplify operation and to supply a permanent print of the transmitted material. The electrolytic process used in recording eliminates photo developing and printing and avoids the mess, dogging and corrosion of previous electrolytic methods. The paper is moistened no more than is absolutely necessary, and as it passes out of the machine it is completely dried. Ultraviolet light fixes the chemicals so that neither the printing nor the background will fade. The clogging and corrosive action of the chemical solution is eliminated by keeping separate the two components of the solution until applied to the paper.