Patent US3944748A successfully refreshed from Google Patents.
US3944748A
Expired / Lapsed
US
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Means and method of reducing interference in multi-channel reproduction of sounds
Assignee: ELAC Electroacustic GmbH
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Filing: 1973-10-31
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Granted: 1976-03-16
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Expires: 1993-10-31
Abstract
Abstract Means and method of reducing the distortion or channel separation due to interference voltages between the reproduction channels in multi-channel reproduction of acoustic sounds in systems having at least two different channels are described. The steps are deriving a control voltage from the low and high interference voltages which occurs in a channel which is proportional to the magnitude of the interference voltages, and using the control voltages as an adjustment to control the distortion or channel separation. The control voltages may be derived from a single channel. The control voltages may be combined to yield a single control signal. Both equal-phase distortion and phase-opposition distortion may be suppressed.
Inventors
- 👤 Hans-Robert Kuhn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:23
CPC Classifications
H; H04; H04S; H04S1/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
75 words
Method of suppressing interference voltages in multi-channel reproduction of acoustic sounds in systems having at least two different channels by reducing the channel separation, comprising the steps of, deriving control voltages from and proportional to low and high frequency interference voltages, respectively, which occur in one of said channels, and utilizing said control voltages to control the channel separation in both a phase-opposite sense and in an equal phase sense to thereby suppress the interference.
Claim 2
Dependent Claim
75 words
Method of suppressing interference voltages in multi-channel reproduction of acoustic sounds in systems having at least two different channels by reducing the channel separation, comprising the steps of, deriving control voltages from and proportional to low and high frequency interference voltages, respectively, which occur in one of said channels, and utilizing said control voltages to control the channel separation in both a phase-opposite sense and in an equal phase sense to thereby suppress the interference.
Claim 3
Independent Claim
82 words
A method of suppressing interference voltages in multi-channel reproduction of acoustic sounds in systems having at least two different channels by reducing the channel separation, comprising the steps of, separately deriving control voltages from and proportional to the low and high frequency interference voltages from a single one of said channels, combining the separately derived control voltages to produce a control signal, and utilizing said control signal to control the channel separation in a dual phase-opposite sense to thereby suppress the interference.
Claim 4
Independent Claim
82 words
A method of suppressing interference voltages in multi-channel reproduction of acoustic sounds in systems having at least two different channels by reducing the channel separation, comprising the steps of, separately deriving control voltages from and proportional to the low and high frequency interference voltages from a single one of said channels, combining the separately derived control voltages to produce a control signal, and utilizing said control signal to control the channel separation in a dual phase-opposite sense to thereby suppress the interference.
Claim 5
Dependent Claim
38 words
Method according to claim 2, including the step of deriving the control voltages that are proportional to the magnitude of the interference voltages, and simultaneously and continuously providing purely phase-opposed crosstalk between said channels by said control signal.
Claim 6
Independent Claim
92 words
A device for suppressing low and high frequency interference voltages in multi-channel reproduction systems of acoustic sounds having at least two different channels by reducing channel separation, comprising a low pass filter and a high pass filter for deriving control voltages respectively proportional to the low and high frequency interference voltages from a single one of said channels, means for combining the separately derived control voltages to produce a control signal, and control means responsive to said control signal for controlling the channel separation in said channels in a dual phase-opposite sense.
Claim 7
Independent Claim
92 words
A device for suppressing low and high frequency interference voltages in multi-channel reproduction systems of acoustic sounds having at least two different channels by reducing channel separation, comprising a low pass filter and a high pass filter for deriving control voltages respectively proportional to the low and high frequency interference voltages from a single one of said channels, means for combining the separately derived control voltages to produce a control signal, and control means responsive to said control signal for controlling the channel separation in said channels in a dual phase-opposite sense.
Claim 8
Independent Claim
81 words
A device for suppressing low and high frequency interference voltages in multi-channel reproduction systems of acoustic sounds having at least two different channels by reducing channel separation, comprising means for deriving control voltages, respectively, proportional to the low and high frequency interference voltages from the interference voltages which occur in one of said channels, and control means connected to the voltage deriving means to control the channel separation in said channels in both a phase-opposite sense and in an equal-phase sense.
Claim 9
Independent Claim
81 words
A device for suppressing low and high frequency interference voltages in multi-channel reproduction systems of acoustic sounds having at least two different channels by reducing channel separation, comprising means for deriving control voltages, respectively, proportional to the low and high frequency interference voltages from the interference voltages which occur in one of said channels, and control means connected to the voltage deriving means to control the channel separation in said channels in both a phase-opposite sense and in an equal-phase sense.
Claim 10
Dependent Claim
164 words
The device as in claim 5, wherein said channels each have at least first and second amplifiers, said control voltages being derived from one of said channels, and comprising low pass filter means and high pass filter means connected to receive said interference voltages from said one of said channels, limiter means connected to the output of said low pass and high pass filter means, control means connected to the output of said limiter means, first, second and third photo-resistor means optically connected to the output of said control means, the first photo-resistor means being connected to the inputs of the first amplifiers, the second photo-resistor means being connected to the output of said second amplifier in said one of said channels and to the output of the first amplifier in the other channel, the third photo-resistor being connected to the output of the first amplifier in said one of said channels and to the output of the second amplifier in said other channel.
Claim 11
Dependent Claim
47 words
The device as in claim 5, wherein said means for deriving control voltages comprises a low pass filter and a high pass filter connected to receive said interference voltages from the same channel, and means for interconnecting the outputs of said filters and feeding said control means.
Claim 12
Independent Claim
19 words
The device as in 7, further comprising means for adjusting the amplitude of the feed to said control means.
Claim 13
Independent Claim
19 words
The device as in 7, further comprising means for adjusting the amplitude of the feed to said control means.
References Cited (Backward Citations)
US3539729A
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US3673342A
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US3745254A
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US3753159A
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US3786193A
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US3823268A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-16 | 1979-09-15 | 1980-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-16 | 1983-09-15 | 1984-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-16 | 1987-09-15 | 1988-03-16 | $7700.00 | Window Closed / Lapsed |