Journal of the Society of Motion Picture Engineers ( Volume: 47, Issue: 6, December 1946)
[ACTIVE]
An Improved 200-Mil Push-Pull Density Modulator
Metadata
- Publisher
- SMPTE — White Plains, NY, USA
- Doc Type
- Journal Article
- Content Type
- Original Research
- Abbreviated Title
- J SMPE
- Volume
- 47, No. 6, pp. 494–518
- Abstract
- A completely new variable-density modulator utilizing a three ribbon push-pull valve is described. The entire valve is sealed by the force of the Alnico V permanent magnet on the Permendur pole pieces. Signal is applied to the center ribbon and noise-reduction currents are applied to the outer ribbons. True class A push-pull operation is obtained from the two component single ribbon valves by the use of an inverter prism which aligns the modulating and noise-reduction edges of each aperture. An anamorphote condenser lens is used to eliminate lamp filament striations at the valve ribbon plane. An anamorphote objective lens gives a 4:1 reduction of the valve aperture in the vertical plane at the film and a 2:1 reduction along the length of the sound track. A meter is supplied to measure exposure as well as setting up “bias.” A photocell monitor is supplied and a “blooping” light for indicating synchronous start marks. Mathematical analysis of the exposure produced by the modulating ribbon is appended as well as a similar analysis of the four ribbon push-pull valve which the new valve supersedes.
- Publication Date
- 1946-12-01
- DOI
10.5594/J12752- ISSN
- Print:
0097-5834 - Link
- https://doi.org/10.5594/J12752
- Author(s)
- J. G. FrayneT. B. CunninghamV. Pagliarulo
- Copyright
- © 1946 Society of Motion Picture and Television Engineers, Inc.
Bibliographic Reference(s)
- 1 Frayne J. G. Silent H. C. : “Push-Pull Recording with the Light Valve,” J. Soc. Mot. Pict. Eng. , XXXI , 1 (July 1938 ), p. 46 . EXTERNAL
- 2 Shea T. E. Herriott W. Goehner W. R. : “The Principles of the Light Valve,” J. Soc. Mot. Pict. Eng. , XVIII , 6 (June 1932 ), p. 697 . EXTERNAL
- 3 Frayne J. G. Scoville R. R. : “Analysis and Measurement of Distortion in Variable-Density Recording,” J. Soc. Mot. Pict. Eng. , XXXII , 6 (June 1939 ), p. 648 . EXTERNAL
- 4 Wente E. C. Biddulph R. : “A Light Valve for the Stereophonic Sound-Film System,” J. Soc. Mot. Pict. Eng. , XXXVII , 4 (Oct. 1941 ), p. 397 . EXTERNAL
- 5 Williams H. G. : “Predicting Spring Performance of Beryllium Copper Wire and Strip,” Iron Age , Reprint, July 8, 1943 . EXTERNAL
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J. G. Frayne, T. B. Cunningham, and V. Pagliarulo; An Improved 200-Mil Push-Pull Density Modulator, Journal of the Society of Motion Picture Engineers ( Volume: 47, Issue: 6, December 1946); SMPTE, 1946. Available at https://doi.org/10.5594/J12752
Snippet:
J. G. Frayne, T. B. Cunningham, and V. Pagliarulo; An Improved 200-Mil Push-Pull Density Modulator, Journal of the Society of Motion Picture Engineers ( Volume: 47, Issue: 6, December 1946); SMPTE, 1946. Available at https://doi.org/10.5594/J12752
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J. G. Frayne, T. B. Cunningham, and V. Pagliarulo; An Improved 200-Mil Push-Pull Density Modulator, Journal of the Society of Motion Picture Engineers ( Volume: 47, Issue: 6, December 1946); SMPTE, 1946. Available at https://doi.org/10.5594/J12752
Snippet:
<span class="citation">J. G. Frayne, T. B. Cunningham, and V. Pagliarulo; <cite>An Improved 200-Mil Push-Pull Density Modulator</cite>, Journal of the Society of Motion Picture Engineers ( Volume: 47, Issue: 6, December 1946); SMPTE, 1946. Available at <a href="https://doi.org/10.5594/J12752" target="_blank" rel="noopener">https://doi.org/10.5594/J12752</a></span>
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J. G. Frayne, T. B. Cunningham, and V. Pagliarulo; An Improved 200-Mil Push-Pull Density Modulator, Journal of the Society of Motion Picture Engineers ( Volume: 47, Issue: 6, December 1946); SMPTE, 1946
doi: 10.5594/J12752
url: https://doi.org/10.5594/J12752
doi: 10.5594/J12752
url: https://doi.org/10.5594/J12752
Snippet:
<li> J. G. Frayne, T. B. Cunningham, and V. Pagliarulo; <cite id="bib-10-5594-j12752">An Improved 200-Mil Push-Pull Density Modulator</cite>, Journal of the Society of Motion Picture Engineers ( Volume: 47, Issue: 6, December 1946); SMPTE, 1946 <span class="doi">10.5594/J12752</span> </li>
Referenced By
- A Versatile Photographic Recording System for Studio Use [Active]
- History of Sound Motion Pictures [Active]
- Variable-Area Recording with the Light Valve [Active]
- Variable-Area Light-Valve Modulator [Active]
- A Compatible Photographic Stereophonic Sound System [Active]
- Direct-Positive Variable-Area Recording with the Light Valve [Active]