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2 June 1988 Development Of The Drexler Optical-Card Reader/Writer System
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Proceedings Volume 0899, Optical Storage Technology and Applications; (1988)
Event: 1988 Los Angeles Symposium: O-E/LASE '88, 1988, Los Angeles, CA, United States
An optical-card reader/writer optical and electronic breadboard system, developed by SRI International under contract to Drexler Technology, is described. The optical card, which is the same size as a credit card, can contain more than 2 megabytes of digital user data, which may also include preformatted tracking information and preformatted data. The data layout on the card is similar to that on a floppy disk, with each track containing a header and clocking information. The design of this optical reader/writer system for optical cards is explained. Design of the optical card system entails a number of unique issues: To accommodate both laser-recorded and mass-duplicated information, the system must be compatible with preencoded information, which implies a larger-than-normal spot size (5 gm) and a detection system that can read both types of optical patterns. Cost-reduction considerations led to selection of a birefringent protection layer, which dictated a nonstandard optical system. The non-polarization-sensitive optics use an off-axis approach to detection. An LED illumination system makes it possible to read multiple tracks.
© (1988) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Gerald Apffel Pierce "Development Of The Drexler Optical-Card Reader/Writer System", Proc. SPIE 0899, Optical Storage Technology and Applications, (2 June 1988);


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