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US4644422A Expired / Lapsed US ⏱️ 0.0 years remaining

Anti-copy system

Assignee: TVI SYSTEMS Ltd
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Filing: 1983-06-24
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Granted: 1987-02-17
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Expires: 2003-06-24
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Abstract

Abstract An anti-copy system which prevents copying of tapes and records and other source material by placing a degrade signal on an analog source signal to be recorded on a recording device. One embodiment of the system includes a pulse width modulation (PWM) circuit that generates a pulsed signal in a frequency range from near the upper end to well above the range of hearing. The PWM pulsed signal is modulated by the source signal to be recorded. The PWM signal becomes the degrade signal. This degrade signal is keyed so that it is combined with the source signal only when the frequency of the source signal exceeds a desired threshold. The combined source signal and degrade signal are recorded on the original recording. This original recording can be played back without the presence of the degrade signal impacting the audible quality of the reproduced source signal. However, attempts to make taped copies of the original recordings cause the degrade signal to beat against the bias oscillator frequency of the tape recording head, thereby creating harmonic signals that result in distortion and noticeable alteration of the reproduced source signal that are unpleasant and objectionable to the listener. The anti-copy system may be used with stereophonic recordings, monophonic recordings, or even digital recordings of the type wherein an audible tone burst is used to represent desired digital data.

Inventors

  • 👤 John C. Bedini

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 04:52
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/00086; G11B20/00731; G11B20/00818; G11B20/00826

Claims Analysis

Total Claims: 51
Claim 1
Independent Claim 84 words
A system for preventing the copying of original recordings comprising: means for generating a source material signal; means for creating a degrade signal which will degrade any source material recorded from an original recording thereof, including a pair of oscillating means and mixing means connected to said oscillating means for mixing the outputs of said oscillating means; means for combining the degrade signal with the source material signal to produce a combined signal; and means for recording said combined signal on said original recording.
Claim 2
Independent Claim 84 words
A system for preventing the copying of original recordings comprising: means for generating a source material signal; means for creating a degrade signal which will degrade any source material recorded from an original recording thereof, including a pair of oscillating means and mixing means connected to said oscillating means for mixing the outputs of said oscillating means; means for combining the degrade signal with the source material signal to produce a combined signal; and means for recording said combined signal on said original recording.
Claim 3
Dependent Claim 20 words
The system according to claim 1 in which said pair of oscillating means comprises a pair of voltage controlled oscillators.
Claim 4
Dependent Claim 28 words
The system according to claim 1 in which one of said pair of oscillators generates a square wave and the other of said oscillators generates a triangular wave.
Claim 5
Dependent Claim 18 words
The system according to claim 1 in which the frequency of the degrade signal is above seventeen kilohertz.
Claim 6
Dependent Claim 18 words
The system according to claim 1 in which the frequency of the degrade signal is above fifty kilohertz.
Claim 7
Dependent Claim 21 words
The system according to claim 5 in which the frequency of the degrade signal is between fifty kilohertz and seventy-five kilohertz.
Claim 8
Dependent Claim 30 words
The system according to claim 1 in which the means for combining the degrade signal with the source material signal includes means for combining the degrade signal in two channels.
Claim 9
Dependent Claim 30 words
The system according to claim 7 in which said means for combining the degrade signal in two channels comprises: phase splitting means for splitting the degrade signal into two components.
Claim 10
Dependent Claim 29 words
The system according to claim 8 in which said pair of oscillating means comprises one oscillator for generating a square wave and another oscillator for generating a triangular wave.
Claim 11
Dependent Claim 19 words
The system according to claim 9 including means for varying the frequency output of said pair of oscillating means.
Claim 12
Dependent Claim 17 words
The system according to claim 9 including means for varying the output level of said mixing means.
Claim 13
Dependent Claim 49 words
The system according to claim 10 in which the means for varying the frequency includes: a plurality of parallel connected capacitors; and switching means for selectively switching said capacitors in and out of the circuit with said pair of oscillating means whereby the frequency output can be selectively varied.
Claim 14
Dependent Claim 18 words
The system according to claim 12 including a potentiometer for varying the frequency output around the preselected frequency.
Claim 15
Dependent Claim 32 words
The system according to claim 10 further including: feedback means, said feedback means being connected to control the output signal of said oscillators according to variations at the output of said oscillators.
Claim 16
Dependent Claim 19 words
The system according to claim 14 in which said feedback means includes means for summing a pair of outputs.
Claim 17
Dependent Claim 31 words
The system according to claim 15 in which said summed outputs are connected through transistor switching means to vary the bias on said pair of oscillators thereby varying the frequency output.
Claim 18
Dependent Claim 25 words
The system according to claim 14 including switch means for switching said feedback means in and out of the circuit to said pair of oscillators.
Claim 19
Independent Claim 86 words
A system for preventing the copying of original recordings comprising: means for generating a source material signal; means for creating a degrade signal which will degrade any source material recorded from an original recording thereof, including a pulse width modulation (PWM) oscillator circuit for generating a pulsed output signal having variable pulse widths in response to a modulation signal; means for combining the degrade signal with the source material signal to produce a combined signal; and means for recording said combined signal on said original recording.
Claim 20
Independent Claim 86 words
A system for preventing the copying of original recordings comprising: means for generating a source material signal; means for creating a degrade signal which will degrade any source material recorded from an original recording thereof, including a pulse width modulation (PWM) oscillator circuit for generating a pulsed output signal having variable pulse widths in response to a modulation signal; means for combining the degrade signal with the source material signal to produce a combined signal; and means for recording said combined signal on said original recording.
Claim 21
Dependent Claim 45 words
The system as defined in claim 18 wherein said means for creating a degrade signal further comprises: pulse amplifier means interposed between said PWM oscillator circuit and said combining means for conditioning said pulsed output signal prior to combining it with the source material signal.
Claim 22
Dependent Claim 85 words
The system as defined in claim 19 wherein said pulse amplifier means comprises: a pre-amplifier circuit for generating a trigger signal only when a desired performance parameter of said source material signal exceeds a specified threshold; and a trigger amplifier circuit responsive to said trigger signal for coupling said pulsed output signal of said PWM oscillator circuit to said combining means when said trigger signal is generated, and for decoupling said pulsed output signal from said combining means when said trigger signal is not generated.
Claim 23
Dependent Claim 20 words
The system as defined in claim 20 wherein said desired performance parameter of the source material signal is its frequency.
Claim 24
Dependent Claim 41 words
The system as defined in claim 20 wherein said pulse amplifier means further comprises photo coupler means interposed between said pre-amplifier circuit and said trigger amplifier circuit for coupling said trigger signal from said pre-amplifier circuit to said trigger amplifier circuit.
Claim 25
Dependent Claim 21 words
The system as defined in claim 18 wherein said modulation signal applied to said PWM circuit comprises said source material signal.
Claim 26
Dependent Claim 25 words
The system as defined in claim 18 wherein said combining means comprises a linear amplifier that sums said source material signal and said degrade signal.
Claim 27
Dependent Claim 16 words
The system as defined in claim 24 wherein said linear amplifier is realized with discrete components.
Claim 28
Dependent Claim 37 words
The sytem as defined in claim 24 wherein said linear amplifier further comprises means for selectively adjusting the signal level of the output signal generated by said linear amplifier prior to recording it on said original recording.
Claim 29
Dependent Claim 71 words
The system as defined in claim 18 wherein the frequency of said degrade signal is selected to fall within a range that will interact with a bias oscillator signal of a recording device used to record a copy of said original recording, said signal interaction causing harmonic signals to be generated that, when played back from the recorded copy, produce objectionable results that unacceptably degrade the quality of said recorded copy.
Claim 30
Dependent Claim 42 words
The system as defined in claim 27 wherein said original recording is recorded on a disc adapted to be rotated on a turntable, and wherein said source material is recorded thereon by selectively varying the shape of a spiraling V-groove cut thereinto.
Claim 31
Dependent Claim 54 words
The system as defined in claim 28 wherein said recording device used to make a copy of said original recording comprises a magnetic recording device, such as a cassette tape recorder, an eight track tape recorder, a reel-to-reel tape recorder, or a recorder circuit used to record the audio track of a video tape.
Claim 32
Dependent Claim 25 words
The system as defined in claim 27 wherein the low end of the selected frequency range of said degrade signal begins at about 17.0 KHz.
Claim 33
Dependent Claim 91 words
An anti-copy system comprising: means for generating a degrade signal; means for combining said degrade signal with a source signal to produce a combined signal; and means for recording said combined signal on an original recording; said degrade signal having one or more frequencies selected to mix with the oscillator signals associated with the recording circuits of magnetic media recording devices so as to generate harmonic or beat frequency signals, the presence of said harmonic signals causing the source signals recorded on the magnetic media to be unacceptably distorted and degraded.
Claim 34
Dependent Claim 91 words
An anti-copy system comprising: means for generating a degrade signal; means for combining said degrade signal with a source signal to produce a combined signal; and means for recording said combined signal on an original recording; said degrade signal having one or more frequencies selected to mix with the oscillator signals associated with the recording circuits of magnetic media recording devices so as to generate harmonic or beat frequency signals, the presence of said harmonic signals causing the source signals recorded on the magnetic media to be unacceptably distorted and degraded.
Claim 35
Dependent Claim 104 words
The anti-copy system as defined in claim 31 wherein said degrade signal generation means comprises: pulse modulation (PWM) circuit means for generating a pulsed output signal having pulse widths that vary in response to said source signal; and triggering means for selectively keying said pulsed output signal so that it is enabled or disabled depending upon whether a trigger signal is present or not; whereby said degrade signal comprises a series of signal bursts, each burst comprising a segment of said pulsed output signal from said PWM circuit, and each burst being separated in time from adjacent bursts as controlled by said trigger signal.
Claim 36
Dependent Claim 26 words
The anti-copy system as defined in claim 32 wherein said trigger signal is generated whenever a specified parameter of said source signal exceeds a specified threshold.
Claim 37
Dependent Claim 19 words
The anti-copy system as defined in claim 33 wherein said specified parameter is the frequency of said source signal.
Claim 38
Dependent Claim 57 words
An anti-copy device comprising: means for generating a degrade signal having one or more frequencies selected to mix with the oscillator signals associated with the recording circuits of magnetic media recording devices so as to generate harmonic or beat frequency signals; and means for combining said degrade signal with a source signal to produce a combined signal.
Claim 39
Dependent Claim 57 words
An anti-copy device comprising: means for generating a degrade signal having one or more frequencies selected to mix with the oscillator signals associated with the recording circuits of magnetic media recording devices so as to generate harmonic or beat frequency signals; and means for combining said degrade signal with a source signal to produce a combined signal.
Claim 40
Dependent Claim 105 words
The anti-copy device as defined in claim 35 wherein said degrade signal generation means comprises: pulse width modulation (PWM) circuit means for generating a pulsed output signal having pulse widths that vary in response to said source signal; and triggering means for selectively keying said pulsed output signal so that it is enabled or disabled depending upon whether a trigger signal is present or not; whereby said degrade signal comprises a series of signal bursts, each burst comprising a segment of said pulsed output signal from said PWM circuit, and each burst being separated in time from adjacent bursts as controlled by said trigger signal.
Claim 41
Dependent Claim 26 words
The anti-copy device as defined in claim 36 wherein said trigger signal is generated whenever a specified parameter of said source signal exceeds a specified threshold.
Claim 42
Dependent Claim 19 words
The anti-copy device as defined in claim 37 wherein said specified parameter is the frequency of said source signal.
Claim 43
Independent Claim 127 words
A method of making an original recording from which acceptable copies cannot be made using conventional recording devices, said method comprising the steps of: (a) generating a source signal representative of the original source material to be recorded; (b) generating a degrade signal having frequencies high enough to be substantially unnoticeable upon playback of said original recording; (c) combining said source signal with said degrade signal to form a combined signal; and (d) recording said combined signal on said original recording, one or more frequencies of said degrade signal having a value such that when mixed with a bias oscillator signal associated with a recording device used to copy said original recording, harmonic signals are generated that significantly and objectionably degrade the quality of the copied recording.
Claim 44
Independent Claim 127 words
A method of making an original recording from which acceptable copies cannot be made using conventional recording devices, said method comprising the steps of: (a) generating a source signal representative of the original source material to be recorded; (b) generating a degrade signal having frequencies high enough to be substantially unnoticeable upon playback of said original recording; (c) combining said source signal with said degrade signal to form a combined signal; and (d) recording said combined signal on said original recording, one or more frequencies of said degrade signal having a value such that when mixed with a bias oscillator signal associated with a recording device used to copy said original recording, harmonic signals are generated that significantly and objectionably degrade the quality of the copied recording.
Claim 45
Dependent Claim 102 words
The method of claim 39 wherein step (b) comprises: (1) generating a pulse width modulated (PWM) signal comprising a series of pulses having variable widths, said widths being a function of a modulation signal, and (2) keying said PWM signal off of a trigger signal such that said PWM signal is enabled when said trigger signal is present and disabled when said trigger signal is not present, whereby said degrade signal comprises a series of signal bursts, each burst comprising a segment of said PWM signal, and each burst being separated in time from adjacent bursts as determined by said trigger signal.
Claim 46
Dependent Claim 100 words
A record comprising a disc having a groove formed therein, each side of said groove representing one channel of a recorded source signal combined with a degrade signal, said degrade signal being of a high enough frequency to be substantially inaudible upon playback of said record, said degrade signal further having one or more frequencies that will interact with the bias oscillator signals of magnetic media recording devices used to copy said record, said interaction causing harmonic signals to be generated, at least one of said harmonic signals causing the source signal recorded on the magnetic media to be distorted.
Claim 47
Dependent Claim 100 words
A record comprising a disc having a groove formed therein, each side of said groove representing one channel of a recorded source signal combined with a degrade signal, said degrade signal being of a high enough frequency to be substantially inaudible upon playback of said record, said degrade signal further having one or more frequencies that will interact with the bias oscillator signals of magnetic media recording devices used to copy said record, said interaction causing harmonic signals to be generated, at least one of said harmonic signals causing the source signal recorded on the magnetic media to be distorted.
Claim 48
Dependent Claim 95 words
In a record having a continuous V-shaped groove formed therein, each side of the groove having modulations formed therein representative of one channel of a source signal, the improvement comprising modulations of said source signal combined with additional modulations representative of a degrade signal said degrade signal having a lowest frequency greater than about 17 KHz, and said degrade signal having at least one frequency that interacts with the bias oscillator signals of the magnetic recording heads so as to generate harmonic signals that are discernible when said magnetic recording is made and played back.
Claim 49
Dependent Claim 95 words
In a record having a continuous V-shaped groove formed therein, each side of the groove having modulations formed therein representative of one channel of a source signal, the improvement comprising modulations of said source signal combined with additional modulations representative of a degrade signal said degrade signal having a lowest frequency greater than about 17 KHz, and said degrade signal having at least one frequency that interacts with the bias oscillator signals of the magnetic recording heads so as to generate harmonic signals that are discernible when said magnetic recording is made and played back.
Claim 50
Dependent Claim 94 words
In a media for storing an audible source signal, the improvement comprising: a degrade signal mixed with said source signal, said degrade signal being of a high enough frequency to be substantially inaudible upon playback of said media, said degrade signal further having one or more frequencies that will interact with the bias oscillator signals of magnetic recording devices used to copy said media, said interaction causing harmonic signals to be generated, at least one of said harmonic signals causing the source signal recorded by the magnetic recording device to be distorted upon playback.
Claim 51
Dependent Claim 94 words
In a media for storing an audible source signal, the improvement comprising: a degrade signal mixed with said source signal, said degrade signal being of a high enough frequency to be substantially inaudible upon playback of said media, said degrade signal further having one or more frequencies that will interact with the bias oscillator signals of magnetic recording devices used to copy said media, said interaction causing harmonic signals to be generated, at least one of said harmonic signals causing the source signal recorded by the magnetic recording device to be distorted upon playback.

References Cited (Backward Citations)

US3004104A Cited
US3963865A Cited
US4040099A Cited
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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) 1990-02-16 1990-08-18 1991-02-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-02-16 1994-08-18 1995-02-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-02-16 1998-08-18 1999-02-17 $7700.00 Window Closed / Lapsed

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