Magnetic recording system with reduction of high frequency signal distortion in vicinity of saturation level

Claim 2

A magnetic recording and reproducing apparatus comprising: a recording amplifier including at least one element for amplifying a signal containing high frequency components to be recorded on a magnetic recording medium and a peaking circuit connected to said element for providing the amplified signal with high frequency compensation, a gain control circuit connected to said recording amplifier and consisting of a variable impedance circuit whose impedance is decreased when said high frequency components exceed a saturation level of said recording medium and a resonant circuit adapted to resonate at the frequency selected in the vicinity of the resonant frequency of the peaking circuit, whereby the level of high frequency components of the signal is suppressed to the vicinity of a saturation level of the recording medium.

Claim 3

A magnetic recording and reproducing apparatus as set forth in claim 1 wherein said amplifying element is a transistor and said gain control circuit is disposed between the collector and the base of said transistor.

Claim 4

A magnetic recording and reproducing apparatus as set forth in claim 1 wherein said variable impedance circuit of the gain control circuit comprises one or more pairs of diodes, each pair including two diodes parallelconnected in a reversed polarity relationship to each other, and said resonant circuit comprises a series connection of an inductance and a capacitance.

Claim 5

A magnetic recording and reproducing apparatus as set forth in claim 3 wherein an output of said amplifying element is applied to the magnetic recording medium through a low-pass filter for removing high frequency components from the output which fall outside a desired frequency range.

Claim 6

A magnetic recording and reproducing apparatus as set forth in claim 1, wherein said peaking circuit includes at least two sets of series connections each comprising an inductance and a capacitance, and said variable impedance circuit of the gain control circuit includes at least two pairs of diodes, each pair comprising two diodes parallel-connected in a reversed polarity relationship to each other, and a switchinG means for selecting either one of said two sets of series connections and either one of said diode pairs depending upon the magnetic characteristics of the magnetic recording medium.

Claim 7

A magnetic recording and reproducing apparatus comprising: a recording amplifier including at least one element for amplifying a signal containing high frequency components to be recorded on a magnetic recording medium and a peaking circuit connected to said element for providing the thus amplified signal with high frequency compensation, a gain control circuit connected to the output of said recording amplifier and consisting of: a variable impedance circuit comprising amplifying means connected to the output of said recording amplifier, a rectifying means for rectifying the signal amplified by said amplifying means and a variable impedance means with its one end grounded whose impedance is decreased by the output of said rectifying means only when said high frequency components exceed a saturation level of said recording medium, and a resonance circuit connected between the other end of said variable impedance means and the input of said recording amplifier adapted to resonate at the frequency selected in the vicinity of the resonance frequency of said peaking circuit, whereby the level of high frequency components of the signal is suppressed to the vicinity of a saturation level of the recording medium.

Claim 8

A magnetic recording and reproducing apparatus comprising: a recording amplifier including at least one element for amplifying a signal containing high frequency components to be recorded on a magnetic recording medium and a peaking circuit connected to said element for providing the thus amplified signal with high frequency compensation, a gain control circuit connected to the output of said recording amplifier and consisting of: a variable impedance circuit comprising amplifying means connected to the output of said recording amplifier, a rectifying means for rectifying the signal amplified by said amplifying means and a variable impedance means with its one end grounded whose impedance is decreased by the output of said rectifying means only when said high frequency components exceed a saturation level of said recording medium, and a resonance circuit connected between the other end of said variable impedance means and the input of said recording amplifier adapted to resonate at the frequency selected in the vicinity of the resonance frequency of said peaking circuit, whereby the level of high frequency components of the signal is suppressed to the vicinity of a saturation level of the recording medium.

Claim 9

A magnetic recording and reproducing apparatus as set forth in claim 6, wherein said amplifying means includes a transistor with its base connected to the output of said recording amplifier and a boosting circuit connected to the emitter of said transistor for amplifying said high frequency components of said signal.

Claim 10

A magnetic recording and reproducing apparatus as set forth in claim 6, wherein said peaking circuit includes at least two sets of series connections each comprising an inductance and a capacitance, said resonance circuit includes at least two sets of series connections each comprising an inductance and a capacitance, and a switching means for selecting either one of said two sets of series connections of said peaking circuit and either one of said two sets of series connections of said resonance circuit, depending upon the magnetic characteristics of the magnetic recording medium.

Claim 11

A magnetic recording and reproducing apparatus as set forth in claim 8, wherein said boosting circuit includes at least two sets of series connections each comprising a capacitance and a resistance and said switching means selects either one of said two sets of series connections of said boosting circuit in association with the selection of said one of the two sets of series connections of said peaking circuit and said resonance circuit.

Claim 14

The method according to claim 10 further comprising the steps of mixing said output of said amplifier means with the output of a bias frequency oscillator prior to said recording step.

Claim 15

The method according to claim 11 further comprising the step of boosting the level of said high frequency compOnents of said signal to effect high frequency compensation thereof.

Claim 16

Apparatus for suppressing saturation-causing high level, high frequency components of a signal prior to the recording of said signal on a magnetic recording medium, which comprises: means for amplifying the portions of said signal having a magnitude below a predetermined saturation level of said recording medium; and means for negatively feeding back to said amplifying means only those portions of said amplified signal which approximate or exceed said predetermined saturation level and a predetermined high frequency whereby the gain of said amplifying means is reduced to thereby prevent high level, high frequency components of said signal from saturating said magnetic recording medium.

Claim 17

Apparatus for suppressing saturation-causing high level, high frequency components of a signal prior to the recording of said signal on a magnetic recording medium, which comprises: means for amplifying the portions of said signal having a magnitude below a predetermined saturation level of said recording medium; and means for negatively feeding back to said amplifying means only those portions of said amplified signal which approximate or exceed said predetermined saturation level and a predetermined high frequency whereby the gain of said amplifying means is reduced to thereby prevent high level, high frequency components of said signal from saturating said magnetic recording medium.

Claim 18

The apparatus according to claim 13 wherein said negative feedback means comprises variable impedance means connected in series with first resonant circuit means.

Claim 19

The apparatus according to claim 14, further comprising a second resonant circuit means connected to said amplifying means for effecting high frequency compensation of said amplified signal.

Claim 20

The apparatus according to claim 15 wherein the resonant frequencies of said first and second resonant circuit means are approximately equal.

Claim 21

The apparatus according to claim 16 wherein said variable impedance means comprises diode means which is biased into conduction at approximately said predetermined saturation level of said magnetic recording medium and which is not in conduction for signals below said saturation level.

Claim 22

The apparatus according to claim 17 wherein said diode means comprises two diodes connected in a parallel, reversed polarity relationship to each other.