JPS5829112A - Magnetic recording and reproducing method - Google Patents

Abstract

PURPOSE:To prevent error in recording and reproduction of a digital information signal, by compensating either one phase of a recording and reproducing signals. CONSTITUTION:A phase equalizer 1 consists of an operational amplifier 3, input resistors R1 and R2 connected between a noninverting and an inverting input terminals of the operational amplifier 3 and an input terminal IN, a feedback resistor R3 connected between the inverting input terminal and an output terminal of the amplifier 3, and a capacitor C connected between the noninverting input terminal of the amplifier 3 and the ground. The output of the amplifier 3 is applied to an output terminal OUT as an output of the phase equalizer 1. Since an input signal is applied to a magnetic recorder and reproducer 2 as a distorted signal, a reproduced output outputted from the device 2 is almost canceled for the distortion with the phase characteristics of the device 2.

Description

[Detailed description of the invention] The present invention relates to a magnetic recording and reproducing method.

In conventional magnetic recording and reproducing methods, when a digital information signal consisting of a rectangular wave signal is recorded and reproduced, the waveform is distorted as shown in Figure 1 due to the phase characteristics determined by the nonlinear magnetization characteristics of the magnetic recording medium and magnetic head. In some cases, incorrect information was reproduced due to the acquisition of a signal with . This tendency was particularly noticeable when a device other than a digital signal recording/reproducing device was used. In order to prevent such inconveniences, it is conceivable to extract sine waveform signal components as shown in FIG. 2 from the output of the magnetic recording/reproducing device using a low-pass filter and then reproduce the information. If they are mixed, the signal level of the high frequency component becomes low as shown in Figure 3, and a reading error occurs in the area surrounded by circle C.
Wrong information will be reproduced.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a magnetic recording and reproducing method that can record and reproduce digital information signals without error.

The magnetic recording and reproducing method according to the present invention compensates the phase of either a recording signal or a reproduction signal using a phase equalizer having a phase characteristic that is almost the opposite of the phase characteristic determined by the magnetization characteristics of a magnetic recording medium and a magnetic head. It is characterized by

Hereinafter, the present invention will be explained in detail with reference to FIGS. 4 to 7.

In FIG. 4, an input signal α consisting of a rectangular wave signal is supplied via a phase equalizer 1 to a magnetic recording/reproducing device 2 which records audio information on an audio track of a video tape or reproduces recorded audio information. has been done. When a signal having a waveform as shown in Fig. 1 is supplied, the phase equalizer 1 can be obtained by integrating the part of the waveform shown in Fig. 1 surrounded by circle A or by differentiating the part surrounded by circle B. It has a function of outputting a signal having a waveform close to the waveform of an input signal consisting of a rectangular wave. That is, when an input signal as shown in FIG. 5(A) is supplied, a signal as shown in FIG. 5(B) obtained by integrating the input signal and a signal as shown in FIG. 5(C) obtained by inverting the input signal are obtained. The signal shown in the figure (E) obtained by combining the signal shown in the figure (D) obtained by differentiating the signal shown in the figure (E)
) is configured to output a signal as shown in FIG.

Now, if the input signal as shown in FIG. 5(A) is ei, then
In each of the signals shown in (B) and (D) of the same figure, S is a complex variable and ω0 is a constant.

The signal shown in FIG. 5(K) is expressed as shown in the following equation.

Therefore, the transfer function T (S) of phase etc. 1 can be determined by the following equation (%) (2) From equation (2), it can be seen that the specific circuit of the phase equalizer 1 should be as shown in FIG. In FIG. 6, the phase equalizer 1 includes an operational amplifier 3, an input terminal IN, and an operational term i.
input resistors R1y and R2 connected between the positive and negative input terminals of the amplifier 3; a feedback resistor R3 connected between the negative input terminal and the output terminal of the amplifier 3; It consists of a capacitor C connected between the positive input terminal and ground. Then, the output of amplifier 3 becomes phase equalizer 1
is supplied to the output terminal OUT as an output.

With the phase equalizer 1 having such a configuration, an input signal consisting of a rectangular wave signal becomes a distorted signal as shown in FIG. As shown in FIG. 7, the reproduced output becomes a signal in which distortion due to the phase characteristics of the magnetic recording/reproducing apparatus 2 determined by the nonlinear magnetization characteristics of the magnetic recording medium and the magnetic head is almost canceled.

In the above embodiment, the phase equalizer 1 is connected to the magnetic recording/reproducing device 2 so that the input signal is distorted in advance and supplied with a phase characteristic opposite to that of the magnetic recording/reproducing device 2. As shown in the figure, it is also conceivable to connect the phase equalizer 1 to receive the reproduction output of the magnetic recording/reproduction device 2 and cancel the distortion in the reproduction output.

As detailed above, in the magnetic recording and reproducing method according to the present invention, phase compensation is performed using a phase equalizer having a phase characteristic that is almost opposite to the phase characteristic determined by the magnetization characteristics of the magnetic recording medium and the magnetic head. Since the reproduced output has substantially the same waveform as the input signal, information can be reproduced without errors. Therefore, according to the present invention, in the mastering process of a video disc, it is possible to write digital information such as a disc control program recorded on an audio track of a video tape onto a master disc without error, and to generate this digital information, e.g. There is no need to separately prepare a data dump generator, and the mastering process can be simplified. In addition, in the magnetic recording and reproducing method according to the present invention, the gain of the phase equalizer is constant regardless of the frequency of the input signal, so when recording and reproducing analog information such as musical tones, the reproduction output obtained by the conventional method is The same reproduction output can be obtained.

In the above embodiment, it is assumed that phase compensation is performed on either the recording input signal or the reproduction output signal of the magnetic recording/reproducing device 2, which is capable of both recording and reproduction.
It is obvious that the recording input signal of a magnetic recording device capable of only recording or the reproduction output signal of a magnetic reproducing device capable of only reproduction may be phase compensated.

[Brief explanation of the drawing]

1 to 3 are waveform diagrams of reproduction output obtained by a conventional magnetic recording and reproduction method, FIG. 4 is a block diagram showing one implementation of the present invention, and FIG. 5 is a diagram of the apparatus shown in FIG. 4. 6 is a circuit diagram showing a specific example of a partial circuit of the device in FIG. 4. FIG. 7 is a waveform diagram of the output of the device in FIG. 4. The figure is a block diagram showing another embodiment of the invention. Explanation of symbols of main parts 1... Phase equalizer 2... Magnetic recording and reproducing device Applicant Univer Myo Pioneer Co., Ltd. Agent Patent attorney ° Fuji Mura Hajime Hikoge 2, Bas 3, tail 4

Claims (1)

[Claims] Magnetic recording characterized in that the phase of either a recording input signal or a reproduction output signal is compensated by a phase equalizer having a phase characteristic almost opposite to the phase characteristic determined by the magnetization characteristics of a magnetic recording medium and a magnetic head. How to play.