Frequency deviation compensation system

Claim 2

In apparatus for compensating an information signal for frequency deviations with the aid of a reference signal having corresponding frequency deviations from a predetermined frequency, the combination comprising means responsive to the information signal for producing a first train of signals at a first rate determined by the frequency of the information signal, means for producing a second train of signals at a fixed section rate determined by the said predetermined frequency, means responsive to the reference signal for producing a third train of signals at a third rate determined by the frequency of the reference signal, and signal generating means responsive to said first, second and third signal trains for producing an output train of signals at a rate determined by the sum of said first and second rates minus said third rate, said signal generating means comprising a reversible accumulator for counting the signals of said first, second and third trains and producing an output signal each time the number of signals of said first and second trains exceeds the number of signals of said third train by a predetermined number.

Claim 3

The apparatus of claim 1, in which said reversible accumulator comprises first reversible counting means responsive to said second and said third train of signals for producing a first error signal each time the number of signals of said second train exceeds the number of signals of said third train by the first predetermined number, and producing a second error signal each time the number of signals of said third train exceeds the number of signals of said second train by said first predetermined number, and second reversible counting means stepped in a first senese by each signal of said first train and by each of said first error signals and stepped in a second sense by each of said second error signals, said second reversible counting means further comprising means for producing an output signal each time said second counting means is stepped in said first sense a second predetermined number of times.

Claim 4

In apparatus for reproducing an information signal frequency modulated on a carrier signal about a first frequency and recorded on a record simultaneously with a reference signal at a constant second frequency, the combination comprising, transducer means for simultaneously reproducing said information signal and said reference signal from the record, first reversible counting means responsive to first and second applied counting signals for producing a third counting signal each time said first counting signals exceed said second counting signals by a first predetermined number, and a fourth counting signal each time said second counting signals exceed said first counting signals by said first predetermined number, means responsive to said reproduced information signal for applying first counting signals to said first reversible counting means at a rate determined by the frequency of said reproduced information signal, signal generating means for applying second counting signals to said first reversible counting means at a fixed rated determined by said second frequency, means responsive to said reproduced information signal for producing fifth counting signals at a rate determined by the frequency of said reproduced information signal, and second reversible counting means responsive to said third, fourth and fifth counting signals for producing a sixth counting signal each time the sum of said fourth and fifth counting signals exceed said third counting signals by a second predetermined number.

Claim 5

In apparatus for reproducing an information signal frequency modulated on a carrier signal about a first frequency and recorded on a record simultaneously with a reference signal at a constant second frequency, the combination comprising, transducer means for simultaneously reproducing said information signal and said reference signal from the record, first reversible counting means responsive to first and second applied counting signals for producing a third counting signal each time said first counting signals exceed said second counting signals by a first predetermined number, and a fourth counting signal each time said second counting signals exceed said first counting signals by said first predetermined number, means responsive to said reproduced information signal for applying first counting signals to said first reversible counting means at a rate determined by the frequency of said reproduced information signal, signal generating means for applying second counting signals to said first reversible counting means at a fixed rated determined by said second frequency, means responsive to said reproduced information signal for producing fifth counting signals at a rate determined by the frequency of said reproduced information signal, and second reversible counting means responsive to said third, fourth and fifth counting signals for producing a sixth counting signal each time the sum of said fourth and fifth counting signals exceed said third counting signals by a second predetermined number.

Claim 6

The apparatus of claim 3, further comprising filter means responsive to said sixth counting signals for producing an alternating output signal at said first frequency modulated by said information signal.

Claim 7

Apparatus for compensating an information signal for frequency deviations with the aid of a reference signal having corresponding frequency deviations, comprising first pulse producing means for producing a stream of pulses at a first rate proportional to the frequency of said information signal, means responsive to said reference signal for substracting pulses from said stream at a second rate proportional to the frequency of said reference signal, second pulse producing means for adding pulses to said stream at a fixed third rate, and filter means responsive to said pulse stream for producing a compensated output signal at a frequency determined by the difference between the sum of said first and third rates and said second rate.

Claim 8

Apparatus for compensating an information signal for frequency deviations with the aid of a reference signal having corresponding frequency deviations, comprising first pulse producing means for producing a stream of pulses at a first rate proportional to the frequency of said information signal, means responsive to said reference signal for substracting pulses from said stream at a second rate proportional to the frequency of said reference signal, second pulse producing means for adding pulses to said stream at a fixed third rate, and filter means responsive to said pulse stream for producing a compensated output signal at a frequency determined by the difference between the sum of said first and third rates and said second rate.

Claim 9

In apparatus for compensating an information signal recorded on a record at a frequency fs + or - Delta fs simultaneously with a reference signal at a frequency fr by transducer means moving relative to the record at a speed N1, and reproduced from the record simultaneously with said referencE signal by transducer means moving relative to the record at a speed N2, whereby said reproduced information signal has a frequency (fs + or - Delta fs)N2/N1, and said reproduced reference signal has a frequency frN2/N1, said apparatus comprising, means responsive to said reproduced information signal for producing a train of first pulses at a rate KM1 (fs + or - Delta fs) N1/N2, means resonsive to said reproduced reference signal for producing a train of second pulses at a rate KM2 fr(N2/N1), means for producing a train of third pulses at a rate KM2 fr, first reversible counting means to said second and third pulses for producing a train of fourth pulses or a train of fifth pulses according as said second pulses exceed said third pulses or said third pulses exceed said second pulses, respectively, by an amount M2fr/M1fs, said fourth and fifth pulses, when produced, each occurring at a rate KM1fs (1-(N2/N1)), and second reversible counting means responsive to said first, fourth and fifth pulses for producing a train of sixth pulses at a rate K(fs + or -(N2/N1) Delta fs).

Claim 10

In apparatus for compensating an information signal recorded on a record at a frequency fs + or - Delta fs simultaneously with a reference signal at a frequency fr by transducer means moving relative to the record at a speed N1, and reproduced from the record simultaneously with said referencE signal by transducer means moving relative to the record at a speed N2, whereby said reproduced information signal has a frequency (fs + or - Delta fs)N2/N1, and said reproduced reference signal has a frequency frN2/N1, said apparatus comprising, means responsive to said reproduced information signal for producing a train of first pulses at a rate KM1 (fs + or - Delta fs) N1/N2, means resonsive to said reproduced reference signal for producing a train of second pulses at a rate KM2 fr(N2/N1), means for producing a train of third pulses at a rate KM2 fr, first reversible counting means to said second and third pulses for producing a train of fourth pulses or a train of fifth pulses according as said second pulses exceed said third pulses or said third pulses exceed said second pulses, respectively, by an amount M2fr/M1fs, said fourth and fifth pulses, when produced, each occurring at a rate KM1fs (1-(N2/N1)), and second reversible counting means responsive to said first, fourth and fifth pulses for producing a train of sixth pulses at a rate K(fs + or -(N2/N1) Delta fs).

Claim 11

The apparatus of claim 6, further comprising counting means responsive to said sixth pulses for producing a train of seventh pulses at a rate fs + or - (N2/N1) Delta fs, and filter means responsive to said sixth pulses for producing an output signal having a frequency fs + or - (N2/N1) Delta fs.

Claim 12

Apparatus for reducing frequency shifts in an information signal recorded on a record at a first frequency simultaneously with a reference signal at a constant second frequency, comprising means for simultaneously reproducing the information signal and the reference signal, a bi-directional signal accumulator, means responsive to said reproduced information signal for adding signals to said accumulator at a rate proportional to the frequency of said reproduced information signal, means for subtracting signals from said accumulator at a rate proportional to the frequency of said reproduced reference signal, means for adding signals to said accumulator at a fixed rate equal to the rate at which said means responsive to said reproduced reference signal would subtract signals in the absence of frequency deviations, means controlled by said accumulator for producing overflow signals when the sum of signals added exceeds the sum of signals subtracted by a predetermined amount, and means responsive to said overflow signals for producing a compensated output signal.

Claim 13

Apparatus for reducing frequency shifts in an information signal recorded on a record at a first frequency simultaneously with a reference signal at a constant second frequency, comprising means for simultaneously reproducing the information signal and the reference signal, a bi-directional signal accumulator, means responsive to said reproduced information signal for adding signals to said accumulator at a rate proportional to the frequency of said reproduced information signal, means for subtracting signals from said accumulator at a rate proportional to the frequency of said reproduced reference signal, means for adding signals to said accumulator at a fixed rate equal to the rate at which said means responsive to said reproduced reference signal would subtract signals in the absence of frequency deviations, means controlled by said accumulator for producing overflow signals when the sum of signals added exceeds the sum of signals subtracted by a predetermined amount, and means responsive to said overflow signals for producing a compensated output signal.

Claim 14

In apparatus for restoring the center frequency to fs of a frequency modulated information signal at a frequency N2/N1 (fs + or - Delta fs) with the aid of a reference signal having a frequency (N2/N1) fr, the combination comprising means responsive to the information signal for producing first pulses at a rate equal to a predetermined multiple of the frequency of said information signal, means responsive to said reference signal for producing second pulses at a rate equal to fs/fr times said multiple of the frequency of said reference signal, means for producing third pulses at a rate fs times said multiple, and inhibiting gate means for producing fourth pulses at a rate equal to the rates of said first and third pulses minus said second pulses.

Claim 15

In apparatus for restoring the center frequency to fs of a frequency modulated information signal at a frequency N2/N1 (fs + or - Delta fs) with the aid of a reference signal having a frequency (N2/N1) fr, the combination comprising means responsive to the information signal for producing first pulses at a rate equal to a predetermined multiple of the frequency of said information signal, means responsive to said reference signal for producing second pulses at a rate equal to fs/fr times said multiple of the frequency of said reference signal, means for producing third pulses at a rate fs times said multiple, and inhibiting gate means for producing fourth pulses at a rate equal to the rates of said first and third pulses minus said second pulses.

Claim 16

The apparatus of claim 9, further comprising means responsive to said fourth pulses for producing fifth pulses at the rate of one for each of said multiple of said fourth pulses.

Claim 17

The apparatus of claim 10, further comprising filter means responsive to said fifth pulses for producing an alternating output signal at the frequency fs + or - (N2/N1) Delta fs.