Method and apparatus of recording and reproducing electrical signals

Claim 2

Apparatus for compensating for time variation components in a television signal reproduced from a magnetic recording and reproducing system, comprising: means for recording a frequency modulated television signal on a magnetic recording medium, said television signal containing a reference signal, a luminence signal and a chrominance signal, said chrominance signal containing said time variation components; first means for reproducing said recorded television signal; second means for separating said chrominance signal containing said time variation components out of said television signal; third means for removing said time variation components From said chrominance signal; fourth means for separating said reference signal out of said reproduced television signal; fifth means for generating a continuous signal having a frequency which is within the frequency band of said frequency modulated television signal and having a phase which is synchronized with the phase of said reference signal; sixth means for obtaining a difference signal corresponding to the difference between said continuous signal and a signal corresponding to said reference signal; seventh means for adding said difference signal and said reproduced television signal; eighth means for detecting the output of said seventh means; ninth means for separating said luminence signal component from the output signal of said eighth means; and tenth means for combining the outputs of said third means and said ninth means to produce a composite television signal substantially free from said time variation components.

Claim 3

The apparatus according to claim 1, wherein: said first means comprises magnetic head means, a first frequency demodulator, and means connecting said magnetic head means to said first frequency demodulator; said second means comprises a band pass filter connected to the output of said first frequency demodulator; said fourth means comprises a separator circuit connected to the output of said band pass filter for separating said reference signal out of said separated chrominance signal; said sixth means comprises an automatic phase control circuit connected to the output of said separator circuit, a first balanced modulator, and means connecting the outputs of said automatic phase control circuit and said fifth means to said first balance modulator; said seventh means comprises a second balanced modulator, means applying said reproduced television signal to said second balanced modulator, and means applying the output of said first balanced modulator to said second balanced modulator; said eighth means comprises a high pass filter and a second frequency demodulator connected to the output of said high pass filter; said ninth means comprises a low pass filter connected to the output of said second frequency demodulator; and said tenth means comprises a mixer means applying the output of said third means to one input of said mixer, and means applying the output of said low pass filter to a second input of said mixer.

Claim 4

The apparatus according to claim 2, wherein said fifth means comprises a fixed frequency oscillator and said sixth means further comprises a frequency multiplier connected between the output of said automatic phase control circuit and the input of said first balanced modulator.

Claim 5

The apparatus according to claim 2, wherein: said means for recording comprises means for frequency modulating a composite color television signal, a further mixer connected to the output of said frequency modulating means, and means connecting the output of said further mixer to further magnetic head means; in the said first means, said means connecting said magnetic head means to said first frequency demodulator includes a further high pass filter; said fifth means comprises a fixed frequency oscillator and a first frequency multiplier connecting said oscillator to said further mixer; in said sixth means, said means connecting the outputs of said automatic phase control circuit and said fixed frequency oscillator includes a second frequency multiplier; in said seventh means, said means applying said reproduced television signal to said second balanced modulator includes a further band pass filter connected to said magnetic head means and a third frequency multiplier connected between said further band pass filter and said second balanced modulator.

Claim 6

Apparatus for compensating for time variation components in a television signal reproduced from a magnetic recording and reproducing system, comprising: first means for reproducing a recorded frequency modulated television signal containing at least one synchronizing signal, a reference signal, a luminence signal and a chrominance signal, said chrominance signal containing said time variation components; second means for separating said chrominance signal containing said time variation components out of said television signal; third means for removing said synchronizing signal from said reproduced television signal and retaining the remainder of said television signal; fourth means for separating said reference signal out of said reproduced television signal; fifth means for generating a continuous signal having a frequency which is within the frequency band of said frequency modulated television signal and having a phase which is synchronized with the phase of said reference signal; sixth means for obtaining a difference signal corresponding to the difference between said continuous signal and a signal corresponding to said reference signal; seventh means for adding said difference signal and said reproduced television signal; eighth means for detecting the output of said seventh means; ninth means for separating said synchronizing signal component from the output signal of said eighth means; and tenth means for combining the outputs of said third means and said ninth means to produce a composite television signal substantially free from said time variation components.

Claim 7

Apparatus for compensating for time variation components in a television signal reproduced from a magnetic recording and reproducing system, comprising: first means for reproducing a recorded frequency modulated television signal containing at least one synchronizing signal, a reference signal, a luminence signal and a chrominance signal, said chrominance signal containing said time variation components; second means for separating said chrominance signal containing said time variation components out of said television signal; third means for removing said synchronizing signal from said reproduced television signal and retaining the remainder of said television signal; fourth means for separating said reference signal out of said reproduced television signal; fifth means for generating a continuous signal having a frequency which is within the frequency band of said frequency modulated television signal and having a phase which is synchronized with the phase of said reference signal; sixth means for obtaining a difference signal corresponding to the difference between said continuous signal and a signal corresponding to said reference signal; seventh means for adding said difference signal and said reproduced television signal; eighth means for detecting the output of said seventh means; ninth means for separating said synchronizing signal component from the output signal of said eighth means; and tenth means for combining the outputs of said third means and said ninth means to produce a composite television signal substantially free from said time variation components.

Claim 8

The apparatus according to claim 5, wherein: said first means comprises magnetic head means, a first frequency demodulator, and means connecting said magnetic head means to said first frequency demodulator; said second means comprises a band pass filter connected to the output of said first frequency demodulator; said third means comprises a sync signal stripper, such that the output signal from said stripper contains substantially all of the components of the output signal of said first frequency demodulator except for said synchronizing signal component; said fourth means comprises a separator circuit connected to the output of said band pass filter for separating said reference signal out of said separated chrominance signal; said sixth means comprises an automatic phase control circuit connected to the output of said separator circuit, a first balanced modulator, and means connecting the outputs of said automatic phase control circuit and said fifth means to said first balanced modulator; said seventh means comprises a second balanced modulator, means applying said reproduced television signal to said second balanced modulator, including a band pass filter connected between said magnetic head means and said second balanced modulator, and means applying the output of said first balanced modulator to said second balanced modulator; said eighth means comprises a high pass filter and a second frequency demodulator connected to the output of said high pass filter; said ninth means comprises a sync signal separator connected to the output of said second frequency demodulator; and said tenth means comprises a mixer, means applying the output of said third means to one input of said mixer, and means applying the output of said sync signal separator to a second input of said mixer.

Claim 9

The apparatus according to claim 6, wherein said fifth means comprises a fixed frequency oscillator and said sixth means further comprises a frequency multiplier connected between the output of said automatic phase control circuit and the input of said first balanced modulator.