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US4087651A Expired / Lapsed US ⏱️ 0.0 years remaining

Optical sound recording system with inversely polarized sound signals

Assignee: Japan Broadcasting Corp
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Filing: 1977-02-22
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Granted: 1978-05-02
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Expires: 1997-02-22
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Abstract

Abstract An optical sound recording system of modified variable area type, wherein a light beam, preferably a laser beam, is pulse-width modulated in response to sound signals and deflected at a high frequency beyond audible range and then recorded on a sound track of cinema film. The pulse-width modulation of the light beam is performed in such a manner that a carrier wave having the same frequency, phase, and wave form to those of the deflection of the light beam and being clipped on both sides of amplitude by a pair of sound signals polarized inversely with each other and biased positively and negatively is used for gating the light beam. Consequently a high quality optical sound recording system unrelated to the carrier waveform used for the pulse-width modulation can be realized.

Inventors

  • 👤 Teiichi Taneda
  • 👤 Yukio Sugiura
  • 👤 Toshio Motoki
  • 👤 Hiroyuki Miyatera
  • 👤 Goichi Oishi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 21:36
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/002; G11B7/003; G11B7/0032; G11B7/12; G11B7/14

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 261 words
An optical sound recording system, wherein a light beam gated in intermittent durations corresponding to momentary amplitudes of a sound signal at a high frequency beyond audible range is deflected in a direction crossing a transporting direction of a film transported continuously at said high frequency and is recorded on said film, comprising (1) a sound signal source, (2) a carrier wave signal source, (3) a deflection signal source for providing a deflection signal, a light source provided for generating said light beam, a first optical means provided for gating said light beam periodically, a second optical means provided for deflecting said light beam gated by said first optical means in said direction and at said high frequency under control of said deflection signal, a third optical means provided for reducing size of a light spot formed by said light beam gated by said first optical means and deflected by said second optical means in response to a width of a sound track formed on said film and for projecting said reduced light spot on said sound track, means coupled to said sound signal source for providing a pair of sound signals polarized oppositely to each other and respectively biased positively and negatively, a pair of comparators provided for comparing respectively sound signals of said pair with said carrier wave having the same frequency, phase and wave form to that of the deflection of said light beam, and an amplifier provided for amplifying and applying output signals derived from said pair of comparators to said first optical means as driving signals.
Claim 2
Dependent Claim 261 words
An optical sound recording system, wherein a light beam gated in intermittent durations corresponding to momentary amplitudes of a sound signal at a high frequency beyond audible range is deflected in a direction crossing a transporting direction of a film transported continuously at said high frequency and is recorded on said film, comprising (1) a sound signal source, (2) a carrier wave signal source, (3) a deflection signal source for providing a deflection signal, a light source provided for generating said light beam, a first optical means provided for gating said light beam periodically, a second optical means provided for deflecting said light beam gated by said first optical means in said direction and at said high frequency under control of said deflection signal, a third optical means provided for reducing size of a light spot formed by said light beam gated by said first optical means and deflected by said second optical means in response to a width of a sound track formed on said film and for projecting said reduced light spot on said sound track, means coupled to said sound signal source for providing a pair of sound signals polarized oppositely to each other and respectively biased positively and negatively, a pair of comparators provided for comparing respectively sound signals of said pair with said carrier wave having the same frequency, phase and wave form to that of the deflection of said light beam, and an amplifier provided for amplifying and applying output signals derived from said pair of comparators to said first optical means as driving signals.
Claim 3
Dependent Claim 20 words
An optical sound recording system as claimed in claim 1, wherein said light source consists of a laser beam source.
Claim 4
Dependent Claim 50 words
An optical sound recording system as claimed in claim 1, wherein said pair of comparators form respectively pulses polarized for blanking said light beam and having pulse durations corresponding to respective parts of said carrier wave extending beyond said positively biased sound signal and below said negatively biased sound signal.
Claim 5
Dependent Claim 35 words
An optical sound recording system as claimed in claim 3, wherein said pulses formed by said pair of comparators are mixed non-additively with blanking pulses corresponding to flyback of the deflection of said light beam.
Claim 6
Dependent Claim 38 words
An optical sound recording system as claimed in claim 1, wherein the deflection of said light beam is effected in a manner corresponding to anyone of the following: a triangular wave, a saw-tooth wave or a sinusoidal wave.
Claim 7
Dependent Claim 19 words
An optical recording system as claimed in claim 5, wherein said second optical means consists of an acoust-optic device.
Claim 8
Dependent Claim 28 words
An optical sound recording system as claimed in claim 5, wherein said second optical means consists of a galvanometer driven by a driving signal having sinusoidal wave form.
Claim 9
Dependent Claim 31 words
An optical sound recording system as claimed in claim 5, wherein said second optical means consists of a rotating polygonal mirror synchronized with a driving signal having a saw-tooth wave form.
Claim 10
Dependent Claim 25 words
An optical sound recording system as claimed in claim 1, wherein said first optical means consists of either an electro-optic device or an acoust-optic device.
Claim 11
Dependent Claim 292 words
An optical sound recording system, wherein a light beam gated in intermittent durations corresponding to momentary amplitudes of a sound signal at a high frequency beyond audible range is deflected in a direction crossing a transporting direction of a film transported continuously and is recorded on said film, comprising a sound signal source, a light source provided for generating said light beam, a first optical means provided for gating said light beam periodically, said high second optical means provided for deflecting said light beam gated by said first optical means in said direction and at said frequency, a third optical means provided for reducing size of a light spot formed by said light beam gated by said first optical means and deflected by said second optical means in response to width of a sound track formed on said film and for projecting said reduced light spot on said sound track, a pulse generator provided for generating a pulse train having said high frequency, a carrier wave generator provided for generating a carrier wave synchronized with said pulse train derived from said pulse generator and used for driving said first and second optical means, means coupled to said sound signal source for providing a pair of sound signals polarized oppositely to each other and respectively biased positively and negatively, a pair of comparators provided for comparing respectively sound signals of said pair with said carrier wave derived from said carrier wave generator, a first amplifier provided for amplifying and applying output signals derived from said pair of comparators to said first optical means as driving signals, and a second amplifier provided for amplifying and applying said carrier wave derived from said carrier wave generator to said second optical means as a driving signal.
Claim 12
Dependent Claim 292 words
An optical sound recording system, wherein a light beam gated in intermittent durations corresponding to momentary amplitudes of a sound signal at a high frequency beyond audible range is deflected in a direction crossing a transporting direction of a film transported continuously and is recorded on said film, comprising a sound signal source, a light source provided for generating said light beam, a first optical means provided for gating said light beam periodically, said high second optical means provided for deflecting said light beam gated by said first optical means in said direction and at said frequency, a third optical means provided for reducing size of a light spot formed by said light beam gated by said first optical means and deflected by said second optical means in response to width of a sound track formed on said film and for projecting said reduced light spot on said sound track, a pulse generator provided for generating a pulse train having said high frequency, a carrier wave generator provided for generating a carrier wave synchronized with said pulse train derived from said pulse generator and used for driving said first and second optical means, means coupled to said sound signal source for providing a pair of sound signals polarized oppositely to each other and respectively biased positively and negatively, a pair of comparators provided for comparing respectively sound signals of said pair with said carrier wave derived from said carrier wave generator, a first amplifier provided for amplifying and applying output signals derived from said pair of comparators to said first optical means as driving signals, and a second amplifier provided for amplifying and applying said carrier wave derived from said carrier wave generator to said second optical means as a driving signal.
Claim 13
Dependent Claim 20 words
An optical sound recording system as claimed in claim 10, wherein said light source consists of a laser beam source.
Claim 14
Dependent Claim 50 words
An optical sound recording system as claimed in claim 10, wherein said pair of comparators form respectively pulses polarized for blanking said light beam and having pulse durations corresponding to respective parts of said carrier wave extending beyond said positively biased sound signal and below said negatively biased sound signal.
Claim 15
Dependent Claim 35 words
An optical sound recording system as claimed in claim 12, wherein said pulses formed by said pair of comparators are mixed non-additively with blanking pulses corresponding to flyback of the deflection of said light beam.
Claim 16
Dependent Claim 38 words
An optical sound recording system as claimed in claim 10, wherein the deflection of said light beam is effected in a manner corresponding to anyone of the following: a triangular wave, a saw-tooth wave or a sinusoidal wave.
Claim 17
Dependent Claim 25 words
An optical sound recording system as claimed in claim 10, wherein said first optical means consists of either an electro-optic device or an acoust-optic device.
Claim 18
Dependent Claim 19 words
An optical recording system as claim in claim 10, wherein said second optical means consists of an acoust-optic device.
Claim 19
Dependent Claim 39 words
An optical sound recording system as claimed in claim 10, wherein said first and second optical means consist respectively of acoust-optic devices and are driven respectively by said carrier wave having either a triangular or a saw-tooth wave form.

References Cited (Backward Citations)

US3335219A Cited
US3819874A Cited
US3854005A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-05-01 1981-10-31 1982-05-02 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-05-01 1985-10-31 1986-05-02 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-05-01 1989-10-31 1990-05-02 $7700.00 Window Closed / Lapsed

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