Phase locked loop having automatic-input tuning and phase control circuits
First Claim
1. An automatic phase-controlled oscillator for producing an output clocking signal whose phase and frequency vary with those of an input information signal applied thereto, comprising;
- information signal input means for receiving said information signal;
control signal means for deriving a control signal representative of the frequency of said input information signal, but deriving said control signal independently from said information signal;
variable-frequency tuning circuit means for receiving said control signal and coupled to said input means for tuning on the basis of said control signal to pass said input information signal as a tuned signal; and
clocking signal generating circuit means for providing said output clocking signal in dependence upon the phase of said tuned signal.
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Accused Products
Abstract
An automatic phase-controlled oscillator circuit for producing an output clocking signal whose phase and frequency vary with those of an input information signal applied thereto comprises an input circuit for receiving the input information signal; a variable-frequency tuning circuit for receiving a control signal and coupled to the input circuit for tuning on the basis of the frequency of the control signal to pass the information signal as a tuned signal; and a clocking signal generator, such as a phase-locked loop circuit, for providing the output clocking signal in dependence upon the phase of the tuned signal. The invention is favorably applied to a digital video tape recorder (DVTR) wherein the information signal is a digital signal reproduced from a tape as a result of relative motion between the tape and the DVTR, and the control signal is also reproduced from the tape to represent such relative motion. The oscillator circuit also preferably includes a phase comparator providing an error signal representing the phase difference as between the input information signal and the output clocking signal, and a phase adjuster, such as a variable delay line, responsive to the error signal.
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Citations
17 Claims
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1. An automatic phase-controlled oscillator for producing an output clocking signal whose phase and frequency vary with those of an input information signal applied thereto, comprising;
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information signal input means for receiving said information signal; control signal means for deriving a control signal representative of the frequency of said input information signal, but deriving said control signal independently from said information signal; variable-frequency tuning circuit means for receiving said control signal and coupled to said input means for tuning on the basis of said control signal to pass said input information signal as a tuned signal; and clocking signal generating circuit means for providing said output clocking signal in dependence upon the phase of said tuned signal. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 17)
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2. An automatic phase-controlled oscillator circuit for producing an output clocking signal whose phase and frequency vary with those of an input information signal in the form of a signal reproduced from a tape by a tape reproducing device as a result of relative motion between said tape and said reproducing device, and wherein a control signal reproduced independently of said reproduced signal but representative of the frequency of said reproduced signal is generated to represent said relative motion;
- comprising;
input means for receiving said information signal; variable-frequency tuning circuit means for receiving said control signal and coupled to said input means for tuning on the basis of said control signal to pass said information signal as a tuned signal; and clocking signal generating circuit means for providing said output clocking signal in dependence upon the phase of said tuned signal. - View Dependent Claims (3)
- comprising;
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14. An automatic phase-controlled oscillator circuit for producing an output clocking signal whose phase and frequency vary with those of an input information signal applied thereto and employing a control signal representative of the frequency of said input information signal but derived independently therefrom;
- comprising;
input means for receiving said information signal; variable-frequency tuning circuit means for receiving said control signal and coupled to said input means for tuning on the basis of said control signal to pass said input information signal as a tuned signal, including variable tank circuit means arranged to receive and pass said information signal and having a tuning input, and integrator circuit means for providing to said tuning input said control signal as a voltage level that varies in accordance with the frequency of control pulses applied thereto, said integrator circuit being formed as a monostable multivibrator followed by a low pass filter; and clocking signal generating circuit means for providing said output clocking signal in dependence upon the phase of said tuned signal.
- comprising;
Specification