JPH0770011B2 - Recording apparatus and recording distortion removing method thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a recording apparatus for recording information on a recording medium by magnetic conversion and a recording distortion removing method thereof.

(Prior Art) Generally, for example, when recording information on a magnetic tape, an audio signal or a video signal is magnetically modulated to magnetize a recording surface of the magnetic tape, and information is reproduced by a voltage according to a leakage magnetic flux from the recording surface. Is done by reading the changes in.

As a device for recording / reproducing information on / from such a magnetic tape, there is, for example, a multi-head tape deck.

This is a device for recording / playback using a magnetic tape wound on a reel, and is characterized in that the usage of the magnetic tape can be freely selected according to the purpose. In addition, the configuration of the magnetic head includes a three-head system having three magnetic heads for recording, reproducing and erasing, and a two-head system having two magnetic heads for both recording / reproducing and erasing.

FIG. 2 shows a tape deck in which the magnetic head has a three-head system.

As shown in the figure, the tape deck has a signal input terminal 1
A recording amplifier 2 for amplifying the audio signal from the audio signal to a predetermined level, a bias oscillator circuit 5 having a variable resistor 4 for adding a bias signal to the amplified audio signal for increasing the magnetization efficiency of the magnetic tape, and a magnetic tape 6. A recording head 7 is provided that magnetizes the recording surface based on audio signals.

On the upstream side of the recording head 7, the direction of magnetization of the recording surface of the magnetic tape 6 to be magnetized is changed to one direction on the basis of an erasing signal from the erasing circuit 8, thereby erasing the already recorded information. An erasing head 9 is provided.

At the downstream side of the recording head 7, a reproducing head 10 for reading information recorded by a change in voltage according to leakage flux from the recording surface of the magnetic tape 6, a reproducing amplifier for amplifying the read audio signal to a predetermined level. 11. An output terminal 12 for outputting the amplified audio signal is provided.

When recording information, the erasing head 9 and the recording head 7 are driven, and the recording head 7 writes information on the recording surface of the magnetic tape 6 which is erased by the erasing head 9. On the other hand, at the time of reproducing information, only the reproducing head 10 is driven, and the information written by the recording head 7 is read.

For high-end models, the playback head is used when recording information.
There is also a tape deck that can drive 10 and monitor simultaneous playback.

By the way, there are various factors such as tape noise, modulation noise, hum, shot noise, harmonic distortion, and intermodulation distortion, which are noise elements generated in the process of recording / reproducing information on such a tape deck. The noise particularly audible to the ear includes tape noise and modulation noise.

Tape noise is the noise that the magnetic tape itself has,
Its reduction is achieved by noise reduction such as Dolby NR. The modulation noise is due to instability of contact between the magnetic tape and the magnetic head, vibration of the tape, wow and flutter, and the like, and is related to whether the magnetic tape and the tape run.

(Problems to be Solved by the Invention) By the way, in recent years, it has been desired to develop a tape deck that reproduces sounds of even higher quality, and it is particularly important to reduce the above-mentioned various noises and distortions.

However, in the above-described conventional tape deck, even if the simultaneous replay monitor can be performed by using the re-head during recording of information, the monitor signal is fed back to cancel various noises during replay of the magnetic tape. No one adopted the technology.

The present invention has been made in response to such a situation,
An object of the present invention is to provide a recording device capable of reproducing high quality information and a recording distortion removing method thereof.

(Means for Solving the Problems) The recording apparatus of the present invention comprises a first magnetizing means for magnetizing a recording surface of a recording medium based on an input signal, and a recording surface magnetized by the first magnetizing means. Monitoring means for monitoring a change in voltage according to the leakage magnetic flux; reference signal generating means for generating a reference signal for detecting a time lag between the time of magnetization by the first magnetizing means and the time of monitoring by the monitoring means. A reference signal adding means for adding the reference signal to the input signal; a distortion component extracting means for comparing a monitor output by the monitor means with the input signal to extract a distortion component included in the monitor output; First reference signal extracting means for extracting the reference signal component from the monitor output, and second reference signal extracting means for extracting the reference signal component from the output of the reference signal adding means. Provided between the comparison means for comparing the outputs of the first reference signal extracting means and the second reference signal extracting means, and the reference signal adding means and the second reference signal extracting means, Delay means for delaying the output signal of the reference signal adding means on the basis of the output of the means, and distortion for canceling the distortion component extracted by the distortion component extracting means on the basis of the monitor output and the output of the delay means. It is characterized by further comprising: a generating unit that generates the input signal to which the cancel signal is added, and a second magnetizing unit that magnetizes the recording surface of the recording medium based on the output of the generating unit.

Further, in the recording distortion removing method of the recording apparatus of the present invention, a reference signal for detecting a time lag between the time of magnetization by the first magnetizing means and the time of monitoring by the monitor means is added at the time of recording information. After the recording surface of the recording medium is magnetized by the first magnetizing means on the basis of the input signal, the monitor means reads the change in voltage according to the leakage magnetic flux from the recording surface, and the distortion component extracting means monitors the monitor. Comparing the monitor output by the means with the input signal to extract the distortion component contained in the monitor output, and then the first reference signal extracting means extracts the distortion component from the monitor output; The comparison means compares the reference signal component extracted from the input signal added with the reference signal by the reference signal extraction means with the comparison means, and based on the output of the comparison means, The input signal to which the quasi-signal is added is delayed by the delay means, and the distortion cancel signal for canceling the distortion component extracted by the distortion component extraction means is added based on the monitor output and the output of the delay means. A signal is generated by the generating means, the recording surface of the recording medium is magnetized based on the output signal of the generating means by the second magnetizing means, and only the monitor means is driven when reproducing the information. It is characterized in that the change in voltage according to the leakage magnetic flux from the recording surface magnetized by the second magnetizing means is read.

(Operation) In the recording apparatus and the recording distortion removing method of the present invention, the recording surface of the recording medium magnetized by the first magnetizing means is monitored by the monitor means, and the distortion component extracting means monitors output and audio or video at the time of input. After the signal is compared with the signal to extract the distortion component at the time of monitoring, the recording surface is recorded by the second magnetizing means on the basis of the signal obtained by adding the distortion cancel signal for canceling the distortion component by the distortion component extracting means to the audio or video signal. Was magnetized. When recording the audio or video signal by the second magnetizing means,
The time lag detected from the monitor output by the monitor means is corrected based on a reference signal for real time correction.

Therefore, since the distortion component at the time of monitoring is canceled by the distortion cancel signal, only a pure audio or video signal is recorded on the recording surface of the recording medium. Further, even if a slight time lag deviation occurs due to instability of the tape running speed, for example, an input signal with a distortion cancellation signal added based on a reference signal for correcting the time lag in real time is recorded. Is reliably removed.

(Example) Hereinafter, the detail of the Example of this invention is described based on drawing.

FIG. 1 shows an embodiment in which the recording apparatus and the recording distortion removing method of the present invention are applied to a multi-head tape deck. Each head described below is arranged toward the magnetic film side of the magnetic tape.

As shown in the figure, the tape deck has signal input terminals 15
A recording amplifier 16 for amplifying the audio signal S _IN from the audio signal S _IN to a predetermined level, a bias oscillation circuit 19 having a variable resistor 18 and adding a bias signal for increasing the magnetic susceptibility to the magnetic tape 17 to the amplified audio signal S _IN. Is provided. The tape deck has a recording head 2 for magnetizing the recording surface of the magnetic tape 17 based on the audio signal S _IN.
0, recording head 2 when monitoring with playback head 23, which will be described later
A single signal oscillating circuit 21 is provided as a reference signal oscillating means for supplying a reference signal for detecting a time lag T with respect to 0. Further, the reference signal adding means means an adder provided on the output side of the single signal oscillating circuit 21 in FIG.

Here, the time lag T is the recording head 20 and the reproducing head 23.
Assuming that the interval between and is L and the traveling speed of the magnetic tape 17 is C, then T = L / C seconds.

When the heads 20 and 23 are provided close to each other, the time lag T is a predetermined distance L because the magnetic fields are mutually disturbed by the leakage magnetic flux from the heads 20 and 23.
Is required. Further, the purpose of detecting the time lag T is that it is necessary to establish synchronization when comparing the signal from the signal input terminal 15 and the signal at the time of monitoring.

Further, the oscillation frequency of the single signal oscillation circuit 21 is
Values above the audio band are preferred, eg 20KHz
It is said that. That is, the frequency range for recording / reproducing information is set to about 20 to 20,000 Hz at the maximum.

On the upstream side of the recording head 20, the direction of magnetization of the recording surface of the magnetic tape 17 to be magnetized is changed to one direction on the basis of an erasing signal from the erasing circuit 22a, thereby erasing the already recorded information. An erasing head 22 is provided.

On the downstream side of the recording head 20, a reproducing head 23 for reading information recorded by a voltage change according to a leakage magnetic flux from the recording surface of the magnetic tape 17, a reproducing amplifier for amplifying the read audio signal to a predetermined level. 24, an output terminal 25 for outputting the audio signal amplified by the reproduction amplifier 24 at the time of reproducing information is provided.

An erasing head 26 that erases information recorded by the recording head 20 based on an erasing signal from the erasing circuit 26a is provided on the downstream side of the reproducing head 23.

On the downstream side of the erasing head 26, the magnetic tape 17 based on the audio signal S _IN -D amplified by the reproducing amplifier 27.
A recording head 28 for magnetizing the recording surface of is provided.

Here, D indicates the modulation distortion when the reproducing head 23 monitors. The characteristics of the recording head 28 are that the recording head 20
Is the same as.

Between the output side of the playback amplifier 24 and the input side of the playback amplifier 27, the audio signal SIN from the input terminal 15 and the playback amplifier 2
An adder 29 is provided as a distortion component extracting means for adding the audio signal S _IN + D added with the modulation distortion D from 4 and outputting only the modulation distortion D. Here, the generation means means a subtracter provided on the output side of the adder 29 in FIG.

Between the output side of the reproduction amplifier 24 and the input side of the adder 29,
A single signal detection circuit 30 for detecting a single signal included in the output of the reproduction amplifier 24 and a single signal detection circuit 31 for detecting a single signal from the single signal oscillation circuit 21 are provided. Further, between them, a phase comparator 32 and a phase comparator 32 that perform phase comparison based on the outputs from these detection circuits 30 and 31.
A delay circuit 33 for correcting the time lag T based on the output of

The tape deck having such a configuration operates as follows.

First, when the audio signal S _IN from the signal input terminal 15 is input, the audio signal S _IN is amplified to a predetermined level by the recording amplifier 16 and then supplied to the recording head 20. The recording head 20 magnetizes the recording surface of the magnetic tape 17 by magnetic modulation based on the amplified signal.

At this time, the recording surface of the magnetic tape 17 to be magnetized is demagnetized by the driving of the erasing head 22, and a signal to which the modulation distortion D by the recording head 20 is added in addition to the signal S _IN is recorded on the recording surface. To be done.

Further, the audio signal S _IN at the time of recording includes a single frequency of 20 KHz from the single signal oscillation circuit 21, and further, the bias signal from the bias oscillation circuit 19 causes the magnetic tape 17 by the recording head 20. The magnetic susceptibility to the recording surface of is increased.

Next, when the reproduction head 23 starts monitoring at a time lag T, the monitored audio signal S _IN + D is amplified to a predetermined level by the reproduction amplifier 24 and then input to the non-inverting input of the adder 29. Input to the terminal. On the other hand, the audio signal S _IN from the signal input terminal 15 is input to its inverting input terminal, and the adder 29 outputs only the modulation distortion D which is the difference.

At this time, the single signal detection circuit 30 takes in only the single signal contained in the output of the reproduction amplifier 24 and supplies it to one input terminal of the phase comparator 32. Further, the single signal detection circuit 31 takes in only the single signal from the single signal oscillation circuit 21 and supplies it to the other input terminal of the phase comparator 32.

The phase comparator 32 supplies the phase difference to the delay circuit 33 by comparing these single signals.

The delay circuit 33 receiving the phase difference corrects the time lag T based on the difference and supplies the audio signal S _IN from the inverting input terminal of the adder 29 and the signal input terminal 15 to be supplied to the reproduction amplifier 27 side. Delay.

Therefore, for example, due to unstable tape running speed,
Even if a slight deviation ΔT of the time lag T occurs, the delay circuit
Delay compensation by 33 ensures phase matching of single signals.

As a result, the modulation distortion D from the adder 29 and the signal input terminal
When the composite value S _IN -D of the audio signal S _IN from 15 is supplied to the reproduction amplifier 27, it is amplified to a predetermined level by the reproduction amplifier 27 and then supplied to the recording head 28. here,
-D in the combined value is a distortion cancellation signal that cancels the above-mentioned modulation distortion D.

The recording head 28 magnetizes the recording surface of the magnetic tape 17 by magnetic modulation based on the signal S _IN -D.

At this time, the magnetic tape 17 to be magnetized by the recording head 28
The recording surface of is erased by the erasing head 26.

At this time, the bias signal from the bias oscillation circuit 19 is added to the audio signal S _IN -D at the time of recording.

Therefore, when the audio signal S _IN -D is recorded by the recording head 28 having the same characteristics as the recording head 20, the modulation distortion D is added as described above, but the distortion cancellation signal -D cancels the modulation distortion D. Therefore, only the audio signal S _IN is recorded on the recording surface.

On the other hand, when reproducing information, only the reproducing head 23 is driven, and the change in voltage according to the leakage magnetic flux from the recording surface of the magnetic tape 17 magnetized by the recording head 28 is read.
After being amplified by the reproduction amplifier 24, it is output from the signal output terminal 25 as the audio signal SOUT.

Therefore, the audio signal S _{OUT at} this time is not only the modulation distortion by the recording head 20, but also the distortion component by the reproduction head 23 and the reproduction amplifier 24 is removed at the same time,
Only the audio signal S _IN from which the modulation distortion D is removed becomes.

As described above, in this embodiment, when the audio signal is recorded by the recording head, the distortion cancel signal for canceling the distortion component is also recorded, so that only the pure audio signal is recorded on the recording surface of the magnetic tape. To be done.

In the present embodiment, the case where the present invention is applied to a multi-head tape deck has been described, but the present invention is not limited to this example.
It may be applied to other recording devices adopting an analog recording system such as R and CDV.

(Effects of the Invention) As described above, according to the recording apparatus and the recording distortion removing method of the present invention, the distortion component generated when the second magnetizing means magnetizes the recording surface is canceled by the distortion cancel signal. , The distortion on the recording surface by the second magnetizing means is performed based on the reference signal for correcting the time lag detected from the monitor output by the monitor means in real time, so that the distortion can be surely removed. Since only the pure audio or video signal is recorded on the recording surface of the recording medium, high quality information can be reproduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment in which the recording apparatus and the recording distortion removing method of the present invention are applied to a multi-head tape deck, and FIG. 2 is a block diagram showing a conventional tape deck. 16 ... recording amplifier, 17 ... magnetic tape, 19 ... bias oscillation circuit, 20,28 ... recording head, 21 ... single voice oscillation circuit, 22,26 ... erasing head, 23 ... reproducing head, 24,27
...... Reproduction amplifier, 29 …… Adder, 30,31 …… Single signal detection circuit, 32 …… Phase comparator, 33 …… Delay circuit.

Claims (2)

[Claims] 1. A first magnetizing means for magnetizing a recording surface of a recording medium on the basis of an input signal, and a change in voltage according to a leakage magnetic flux from the recording surface magnetized by the first magnetizing means is monitored. Monitoring means, reference signal generating means for generating a reference signal for detecting a time lag between the time of magnetization by the first magnetizing means and the time of monitoring by the monitoring means, and adding the reference signal to the input signal. Reference signal adding means, distortion component extracting means for comparing the monitor output by the monitoring means with the input signal, and extracting a distortion component included in the monitor output, and extracting the reference signal component from the monitor output. First reference signal extracting means, second reference signal extracting means for extracting the reference signal component from the output of the reference signal adding means, first reference signal extracting means, and The comparison means for comparing the outputs of the second reference signal extraction means and the reference signal addition means provided between the reference signal addition means and the second reference signal extraction means, based on the output of the comparison means. Delay means for delaying the output signal of the means, based on the monitor output and the output of the delay means, the input signal to which the distortion cancellation signal for canceling the distortion component extracted by the distortion component extraction means is added A recording apparatus comprising: a generating unit that generates a magnetic field and a second magnetizing unit that magnetizes a recording surface of the recording medium based on an output of the generating unit. 2. When recording information, the first signal is added based on an input signal added with a reference signal for detecting a time lag between the time of magnetization by the first magnetizing means and the time of monitoring by the monitor means. After magnetizing the recording surface of the recording medium by the magnetizing means, the monitor means reads the change in voltage according to the leakage magnetic flux from the recording surface, and the distortion component extracting means monitors the monitor output by the monitor means and the input signal. After extracting the distortion component contained in the monitor output by comparing the reference signal component extracted from the monitor output by the first reference signal extraction means and the reference signal by the second reference signal extraction means. The reference signal component extracted from the added input signal is compared by a comparison means, and the input signal added with the reference signal based on the output of the comparison means. Is delayed by delay means, based on the monitor output and the output of the delay means, the distortion cancel signal for canceling the distortion component extracted by the distortion component extraction means is generated by the generation means, The second magnetizing means magnetizes the recording surface of the recording medium on the basis of the output signal of the generating means, drives only the monitor means at the time of reproducing information, and magnetizes by the second magnetizing means. A method for removing a recording distortion of a recording device, which comprises reading a voltage change according to a leakage magnetic flux from a recording surface.