US4184178A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drop-out compensator for sound reproducing apparatus during tape reversal
Assignee: BASF SE
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Filing: 1976-10-29
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Granted: 1980-01-15
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Expires: 1996-10-29
Abstract
Abstract The invention comprises a circuit arrangement for a sound-reproducing apparatus, particularly a video tape recorder having an audio channel, wherein upon the occurence of a sound signal drop-out interval within a continuous audio signal, for example within the track-switching period in multi-track sound recordings, an audio frequency signal is inserted in the drop-out interval so that the interval is rendered unnoticeable to the listener. The apparatus can be advantageously employed for recorders in which sound signals are recorded on the tracks of a magnetic tape or disc, or on grooved tracks in a disc. In one preferred embodiment of the invention the arrangement comprises circuitry for attenuating the noise burst which occurs during the track-switching period of a multi-track recorder using a frequency modulated audio signal, the degree to which the noise is attenuated being correlated to the level of the immediately preceding audio signal. Further embodiments of the invention comprise circuitry for inserting audio frequency noise signals of a predetermined level during the drop-out interval.
Inventors
- 👤 Gerhard Rotter
- 👤 Roland H. W. Roos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:37
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/79; H04N9/80; H04N9/802; G; G11; G11B; G11B20/00; G11B20/02; G11B20/025; G11B21/00; G11B21/02; G11B21/022; G11B5/00; H03; H03B; H03B29/00; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/34; H03G3/345; H04N5/00; H04N5/76; H04N5/91; H04N5/93; H04N5/94
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
188 words
In a sound system of the type in which audio information carried sequentially on multiple tracks of a magnetic recording tape is played back, via a playback path terminating in sound reproduction means, with the aid of a reversible tape drive including means for scanning said tape, an arrangement for minimizing the audible effect of dropouts in the reproduced audio information which occur incident to each tape reversal, said arrangement comprising: means for continuously storing a signal varying in dependence on the recorded audio information as it is scanned by said scanning means; means for generating a control signal indicating the occurrence of each said dropout; and switching means controlled by said control signal and in circuit connection with said playback path, said switching means normally supplying to said reproduction means a first audio signal derived from said scanning means, and said switching means operating in response to said control signal to supply to said sound reproduction means, for the duration of each said dropout, a second audio signal correlated to said varying signal as stored by said storing means a predetermined time prior to each said dropout.
Claim 2
Dependent Claim
188 words
In a sound system of the type in which audio information carried sequentially on multiple tracks of a magnetic recording tape is played back, via a playback path terminating in sound reproduction means, with the aid of a reversible tape drive including means for scanning said tape, an arrangement for minimizing the audible effect of dropouts in the reproduced audio information which occur incident to each tape reversal, said arrangement comprising: means for continuously storing a signal varying in dependence on the recorded audio information as it is scanned by said scanning means; means for generating a control signal indicating the occurrence of each said dropout; and switching means controlled by said control signal and in circuit connection with said playback path, said switching means normally supplying to said reproduction means a first audio signal derived from said scanning means, and said switching means operating in response to said control signal to supply to said sound reproduction means, for the duration of each said dropout, a second audio signal correlated to said varying signal as stored by said storing means a predetermined time prior to each said dropout.
Claim 3
Dependent Claim
41 words
The arrangement of claim 1, wherein said audio information is carried on said recording medium in frequency-modulated form, said arrangement further comprising, interposed between said scanning means and said reproduction means, means for demodulating the audio information from said scanning means.
Claim 4
Dependent Claim
79 words
The arrangement of claim 2 wherein the output of said frequency demodulator during each said dropout comprises an audio-frequency noise burst of substantially larger amplitude than said reproduced audio information, said switching means further including means for attentuating said noise burst to a level correlated to said stored signal and thereby producing said second audio signal, whereby the audible effect of said dropouts is reduced by attenuating the noise bursts which occur during the reproduction of said audio information.
Claim 5
Dependent Claim
38 words
The arrangement of claim 1 wherein said storing means comprises means for integrating said first audio signal for said predetermined time prior to each said dropout, said signal stored in the storing means being the integrated audio signal.
Claim 6
Dependent Claim
34 words
The arrangement of claim 1 wherein the amplitude of said second audio signal is between about 0 dB and 6 dB below the average amplitude over said predetermined time of said first audio signal.
Claim 7
Dependent Claim
84 words
The arrangement of claim 1 wherein said storing means comprises means for detecting the envelope of said first audio signal and means for passing with a time delay predetermined low frequency components of said envelope, said low frequency passing means having a time constant at least equal to the length of said dropout, the arrangement further including means for producing a noise signal and means for amplitude modulating said noise signal with said low frequency envelope components, thereby producing said second audio frequency signal.
Claim 8
Dependent Claim
15 words
The arrangement of claim 1 wherein said switching means comprises at least one semiconductor switch.
Claim 9
Dependent Claim
31 words
The arrangement of claim 1 further comprising means for generating an audio frequency signal having an amplitude determined by said stored signal, said second audio signal being said generated audio-frequency signal.
Claim 10
Dependent Claim
41 words
The arrangement of claim 8 wherein said generating means comprises a noise source and a controllable gate for passing the output signal from said noise source to said switching means at an amplitude proportional to the value of said stored signal.
Claim 11
Dependent Claim
58 words
The arrangement of claim 9 wherein said noise source comprises a resistor and a reverse-biased zener diode in series-connection, a capacitor connected to the junction of said series-connected resistor and diode, and a filter connected to said capacitor whereby selected audio frequency components of noise produced by said reverse-biased diode are passed through said capacitor and said filter.
Claim 12
Dependent Claim
55 words
The arrangement of claim 8 wherein said generating means comprises an oscillator connected for receiving an impulse from said storing means when a said dropout occurs and producing for the duration of the dropout an audio frequency oscillation related in amplitude to said stored signal, said produced audio frequency oscillation being said second audio signal.
Claim 13
Dependent Claim
190 words
In a sound system of the type in which audio information carried sequentially on multiple tracks of a magnetic recording tape is played back, via a playback path terminating in sound reproduction means, with the aid of a reversible tape drive including means for scanning said tape, an arrangement for minimizing the audible effect of dropouts in the reproduced audio information which occur incident to each tape reversal, said arrangement comprising: a delay line for continuously storing a signal varying in dependence on the recorded audio information as it is scanned by said scanning means; means for generating a control signal indicating the occurrence of each said dropout; and switching means controlled by said control signal and in circuit connection with said playback path, said switching means normally supplying to said reproduction means a substantially undelayed segment of the audio signal derived from said scanning means, and said switching means operating in response to said control signal to supply to said sound reproduction means, for the duration of each said dropout, the segment of said audio information stored in said delay line a predetermined time prior to each said dropout.
Claim 14
Dependent Claim
190 words
In a sound system of the type in which audio information carried sequentially on multiple tracks of a magnetic recording tape is played back, via a playback path terminating in sound reproduction means, with the aid of a reversible tape drive including means for scanning said tape, an arrangement for minimizing the audible effect of dropouts in the reproduced audio information which occur incident to each tape reversal, said arrangement comprising: a delay line for continuously storing a signal varying in dependence on the recorded audio information as it is scanned by said scanning means; means for generating a control signal indicating the occurrence of each said dropout; and switching means controlled by said control signal and in circuit connection with said playback path, said switching means normally supplying to said reproduction means a substantially undelayed segment of the audio signal derived from said scanning means, and said switching means operating in response to said control signal to supply to said sound reproduction means, for the duration of each said dropout, the segment of said audio information stored in said delay line a predetermined time prior to each said dropout.
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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) | 1983-01-14 | 1983-07-16 | 1984-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-14 | 1987-07-16 | 1988-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-14 | 1991-07-16 | 1992-01-15 | $7700.00 | Window Closed / Lapsed |