Dynamic information storage or retrieval – Specific detail of information handling portion of system – Radiation beam modification of or by storage medium
Patent
1991-09-05
1993-08-17
Dzierzynski, Paul M.
Dynamic information storage or retrieval
Specific detail of information handling portion of system
Radiation beam modification of or by storage medium
369124, G11B 720
Patent
active
052375595
ABSTRACT:
Audio information is recovered from a variable-area optical record, particularly motion picture film variable-area optical soundtracks. A scan signal is obtained by repetitively scanning the optical record substantially transverse to the bias line. The noise reduction effect is enhanced by a threshold detector which is provided with a transversely varying threshold level that varies according to the position of the scan across the width of the soundtrack. A threshold is provided for a bilateral soundtrack, the threshold having a minimum level at the bias line of the soundtrack and increasing progressively with distance from the bias line. Thus, one each scan, the threshold level is high when the scan is at the edge of each soundtrack, falls progressively to a minimum when the scan reaches the bias line, and then increases progressively back to its original high level when the scan is at the other edge of the soundtrack.
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Mosely, J. et al., "The Colortek Optical Stereophonic Sound Film Sytem," SMPTE Journal, vol. 87, pp. 222-232.
Murphy James B.
Richards Martin J.
Beyer Jim
Dolby Laboratories Licensing Corporation
Dzierzynski Paul M.
Gallagher Thomas A.
Lathrop David N.
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