JPS637927Y2 - - Google Patents

Description

[Detailed description of the invention] This invention provides each reproduction signal containing a crosstalk component generated due to the presence of crosstalk between magnetic heads in a multi-channel magnetic recording/reproducing device to a phase inverting means and adjusts the amplitude. By applying it to the output end of each of the above-mentioned phase inverting means of adjacent channels through a coupling circuit including a phase shifting means, a phase shifting means, and a 12 dB/octave bandpass filter means, The present invention relates to a crosstalk reduction device that eliminates the possibility that crosstalk components will increase and can significantly remove crosstalk components in the mid-range.

Conventionally, as a means for removing crosstalk between magnetic heads, a reproduced signal containing a crosstalk component is applied to a phase inverting means, and is transmitted to each of the adjacent channels via a coupling circuit including an amplitude adjusting means and a phase shifting means. It is known that the crosstalk component is applied to the output end of the phase inverting means to remove the crosstalk component. This uses an inverter that also serves as a preamplifier as a phase inversion means, a variable resistor as an amplitude adjustment means, and a parallel circuit of a resistor and a capacitor as a phase shift means. This is inverted by an inverting means, and the reproduced signal containing the other crosstalk component is adjusted to the same level and phase as the crosstalk component of the frequency that is particularly desired to be canceled in the coupling circuit, and then the other signal is combined with The polarity of the reproduced signal containing the crosstalk component is inverted by a phase inverting means, and one of the reproduced signals containing the crosstalk component is inverted by a coupling circuit at the same level and phase as the other crosstalk component of the frequency that is particularly desired to be canceled. By combining the adjusted signals, crosstalk components due to adjacent channel signals present in each channel signal are removed. However, although this conventional method of eliminating crosstalk components by canceling them only through level adjustment and phase shift is effective at the desired frequency, the phase shift of crosstalk components in other frequency ranges, especially in the low and high ranges, is effective. changes drastically depending on the frequency,
Depending on the frequency, it may even increase rather than cancel out. That is, as shown in FIG. 1 or 2, the level of the crosstalk component in the low frequency range is undulating due to the so-called shape effect, and the phase of the crosstalk component changes drastically depending on the frequency. In addition, in the high frequency range, as shown in Figure 3, the phase between the outputs on the L and R sides changes in a very short amount of time due to the influence of touch with the head as the tape runs. It has been known. Similarly, in the case of crosstalk, when considering the crosstalk component where the R side gap picks up the signal of the L side track, this instability is unavoidable. Furthermore, in the high range, in the case of 3 heads etc., when simultaneous recording and playback is performed, although it is slight,
In addition to normal crosstalk, the magnetic flux from the recording head jumps directly into the playback head in addition to the signal picked up by the gap in the tape recording signal, and this appears as the playback output, resulting in a phase shift between the original signal and the head spacing. Due to the so-called feed-through in which signals are generated, a signal whose phase is completely different from that of the reproduced signal during recording may be mixed in.

In such a state, the canceling effect of a signal with a certain phase shift in the low and high frequencies may result in an increase in crosstalk components, which is a problem.

In addition, since the crosstalk component increases in the low and high frequencies, the signal level given to cancel the signal level of the crosstalk component cannot be close to the signal level of the crosstalk component, and the crosstalk component increases. Only a small amount of range was provided in which the effects of increasing components could be avoided. Therefore, there was a problem that a sufficient countervailing effect could not be obtained.

This invention was made in view of these conventional problems, and aims to solve the above problems by providing bandpass filter means of 12 dB/octave or more in the conventional technology.

This invention will be explained below based on the drawings. FIG. 4 is a block diagram of an embodiment of this invention applied to a two-channel magnetic recording/reproducing apparatus.

This invention is composed of a phase inverting means 1 and a coupling circuit 2. The coupling circuit 2 is comprised of an amplitude adjustment means 21, a phase shift means 22, and a bandpass filter means 23 of 12 dB/octave or more.

The phase inverter 1 inverts the polarity of the reproduced signal and uses an inverter. An inverter having an amplification function may be used. The coupling circuit 2 generates a crosstalk canceling signal, and its output is applied to the output terminal of the phase inverting means 1. The amplitude adjustment means 21 is for adjusting the signal level of the crosstalk canceling signal, and uses a variable resistor.

The phase shifting means 22 determines the phase transition of the crosstalk canceling signal and also determines the amount of change in the amplitude of the crosstalk canceling signal depending on the frequency of the signal, and uses a parallel circuit of a resistor and a capacitor.

Band pass filter means 23 of 12 dB/oct or more
Passive filters or active filters are used to pass signals within a certain frequency range but block signals at other frequencies. This bandpass filter means 23 has the problem that the canceling effect of a signal with a constant phase shift in the low and high frequencies may lead to an increase in crosstalk components in some cases, and the resulting crosstalk This is to correct the problem that the signal level of the talk cancellation signal cannot be made close to the signal level of the crosstalk component, and the crosstalk component within a certain frequency range (approximately 100 to 3000Hz) is more than enough. However, crosstalk components at other frequencies are not removed. As a result, there is no sudden change in phase within a certain frequency range, so there is no possibility that crosstalk will increase due to sudden changes in phase, and it is possible to further increase the level of the crosstalk canceling signal. As for bandpass characteristics, it is good to have a large slope of attenuation.At 6dB/oct, the cancellation effect of the bandpass filter over a wide range is lost due to the phase rotation generated by the bandpass filter itself, but at 12dB/oct or more, the canceling effect of the bandpass filter is lost over a wide range. By tilting, malfunctions due to phase rotation occurring in the bandpass filter can be stopped within a narrow range. By combining this signal with a reproduced signal containing crosstalk components, the crosstalk components can be canceled and reduced.

The localization of sound in the sound field is judged by the phase difference between the ears in the low range, but it is known that the phase difference does not matter much in the high range. By reducing crosstalk components (100 to 3000 Hz), sound image localization can be sufficiently improved.

As explained above, this invention supplies each reproduced signal containing a crosstalk component generated due to the presence of crosstalk between magnetic heads to the phase inversion means, and also provides amplitude adjustment means, phase shift means,
Crosstalk caused by sudden changes in phase in a certain frequency range can be eliminated by applying the signal to the output end of each of the above-mentioned phase inversion means of adjacent channels through a coupling circuit including a bandpass filter means of 12 dB/octave or more. The possibility of increase in crosstalk can be eliminated, and the level of the signal for canceling crosstalk can be increased, resulting in the effect that crosstalk components can be largely eliminated.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the frequency characteristics of the crosstalk component, Figure 2 is a diagram showing the phase characteristics of the crosstalk component, Figure 3 is a diagram showing the reproduction output on the R side and L side, and Figure 4 is a diagram showing this invention. Embodiment 2 A diagram showing a block when applied to a channel magnetic recording/reproducing device. FIG. 5 is a diagram showing the frequency characteristics of a bandpass filter means of 12 dB/octave or more. FIG. 6 shows the effect of this invention. It is a diagram. DESCRIPTION OF SYMBOLS 1... Phase inversion means, 2... Coupling circuit, 21...
...Amplitude adjusting means, 22... Phase shifting means, 23...
12dB/oct bandpass filter means, Ha, Hb…
...magnetic head.

Claims (1)

[Scope of utility model registration request] In a multichannel magnetic recording and reproducing device that records and reproduces information on multiple tracks using multiple magnetic heads, each reproduced signal containing a crosstalk component generated due to the presence of crosstalk between the magnetic heads is phase-inverted. The crosstalk component is applied to the output terminal of each of the phase inverting means of the adjacent channel via a coupling circuit including an amplitude adjusting means, a phase shifting means, and a bandpass filter means of 12 dB/octave or more. A crosstalk reduction device that eliminates crosstalk.