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Optical Engineering

Optical Digital Recording
Author(s): J. T. Russell; R. A. Walker
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Paper Abstract

An optical information storage system based on direct binary bit imaging is described. The recorded bit diameters are about one micron, and a density of about 5 x 107 bits/cm2 has been demonstrated. Color television program material has been encoded in a differential PCM format, recorded and played back in real time. The system uses a stationary rec-ord, and a scanned optical aperture that is smaller than usual for these bit densities. The present work has been directed toward a low cost video player/recorder for home use. Optical digital recording is a technique for high density storage of binary information. Each information bit is stored as a discrete, direct image in contrast to the more usual holo graphic transform images. By the use of short focal length lenses and a mechanical scanner a data density of 5 x 1 07 bits per square centimeter and data rates of 3 x 107 bits per second have been demonstrated. For comparison, the information on a typical reel of computer tape (2600 ft at 1600 BPI) could be stored in roughly one square inch on this optical record. This technology was developed for several applications. The first, consumer prerecorded TV, is reported here. This choice was made because a video record would require the highest densities and the simplest, lowest cost player of all the applications considered. In effect, the results of this work would help define those applications that are commercially feasible. Color TV material has been successfully re corded in real time and played back with basically no degredation of the signal. The luminance bandwidth is 3.5 MHz plus the .6 MHz color components. The playback device is simple and probably inexpensive in quantity. Holographic data storage techniques were not used for this work because the inherent advantages of holographic systems can be had with properly designed direct bit systems, while the playback equipment for direct systems appears less expensive. Scanner In contrast to much previous work, the record element is held stationary during re

Paper Details

Date Published: 1 February 1976
PDF: 4 pages
Opt. Eng. 15(1) 150120 doi: 10.1117/12.7971901
Published in: Optical Engineering Volume 15, Issue 1
Show Author Affiliations
J. T. Russell, Battelle Pacific Northwest Laboratories (United States)
R. A. Walker, Battelle Pacific Northwest Laboratories (United States)

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