KR0155735B1 - Recording and reproducing apparatus of the high density digital signal - Google Patents

Abstract

The present invention relates to an apparatus for recording and reproducing a high density digital signal. In order to solve this problem, there is a high probability of a large number of errors occurring in recording and reproducing a high density digital signal. A record equalizer for generating a window signal, which is a signal that detects a section in which an error occurs due to interference between data in advance, and a timing relay is configured at the front of the record amplifier, so that the data in the section where the window signal is generated can be reproduced by reducing the recording current. This is to reduce data detection errors caused by inter-bit interference. Therefore, it is applied to a video tape recorder or a video cassette recorder.

Description

High-density digital signal recording and reproducing device

1 is a block diagram of a digital signal recording and reproducing apparatus according to the prior art.

2 is a waveform diagram of each part according to FIG.

3 is a block diagram showing one embodiment of a digital signal recording and reproducing apparatus according to the present invention;

4 is a detailed circuit diagram of the record equalizer of FIG.

5 is a waveform diagram of each part according to FIG. 4.

* Explanation of symbols for main parts of the drawings

5: time delay 10: record amplifier

20, 25: Head 30: Tape

40: Playback Amplifier 50: Playback Equalizer

60: data detector 62: integrator

64: amplifier 66: comparator

100: record equalizer 110 to 130: monostable oscillator

R1 to R3, R11 to R13: resistors C1 to C3, C11 to C13: capacitors

OR: Ora gate INV: Inverter

22, 52, 54: section in which signals with intervals smaller than the reference interval are input

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording and reproducing apparatus for a high density digital signal, and more particularly, to changing the intensity of the recording current in advance according to the run lenght of data before recording the digital signal on the magnetic recording medium. A high-density digital signal recording and reproducing apparatus that reduces data detection errors caused by interference between bits during reproduction.

Due to the advantages of digital signal processing, it is a clear trend that existing analog signal processing is replaced by digital signal processing. In particular, digital signal processing of audio and video signals is at its peak. In video cassette recorders and the like, not only the digitalization of signal processing but also high density recording and reproducing are enabled in comparison with recording and reproducing.

However, the demand for high picture quality on the screen and the minimization of tape consumption lead directly to the demand for higher density recording reproduction on the tape. Such high-density recording and reproducing is rapidly progressing due to the development of semiconductor technology and the advancement of channel coding technology. However, as the high-density recording and reproducing is performed, the possibility of data detection error during reproduction also increases.

1 is a block diagram of a digital signal recording and reproducing apparatus according to the prior art, wherein a head 20 for recording a signal on a tape is connected to an output terminal of a record amplifier 10 that amplifies the digital signal for recording. The recorder amplifier 10 supplies a recording current suitable for the head 20 and the tape 30. The playback amplifier 40 receives and amplifies the output signal of the playhead 25 as an input.

A playback equalizer 50 for correcting waveform shaping and peak shift is connected to the playback amplifier 40, and a data detector 60 is connected to the playback equalizer 50.

The data detector 60 is an integrator 62, an amplifier 64 connected to the integrator 62, and a comparator 66 for comparing the output signal of the amplifier 64 and the inverted output signal of the amplifier 64. Consists of.

Referring to the conventional circuit configured as described above, although digital data is output from the channel coding unit which processes the data at the front end of the record amplifier 10, the record amplifier 10 outputs the head 20 and the tape ( Supply with a write current suitable for 30).

During playback, the output of the playback head 25 becomes a large signal while passing through the playback amplifier 40, and again after waveform shaping and peak shift correction by the playback equalizer 50 is input to the data detector 60 to be input to digital data. Is played.

FIG. 2 is a waveform diagram of each part according to FIG. 1, and FIGS. 2A to 2E are wave diagrams showing when the input digital signal is low density, and FIGS. This is a waveform diagram showing when the digital signal to be obtained is high density.

When the low-density digital signal recording and reproducing is described with reference to Figs. 2 (a) to (e), it is assumed that the signal recorded on the tape 30 is the same as that of Fig. 2 (a). The output signal is shown in FIG. 2 (b). That is, a pulse (+) is generated at the rising edge of the recording signal, and a pulse (-) is generated at the falling edge.

At this time, the playback equalizer 50 corrects to some extent so as to coincide with the rising edge of the recording current of the pulse and the falling edge. When the output signal of the playback equalizer 50 (see FIG. 2 (b)) is integrated and amplified by the integrator 62, the waveform shown in FIG. The amplifier 64 outputs the amplified signal and the inverted signal of the amplified signal (see FIG. 2 (d)). Comparator 66 compares these two signals.

When the waveform of the uninverted output signal of the amplifier 64 (see FIG. 2 (c)) goes from low to high, the high value is output from the comparator 66 at the point where the waveform meets the inverted waveform. When the waveform of the uninverted output signal of the signal goes from high to low, the low value is output at the point where it meets the inverted waveform (see FIG. 2 (e)). The recorded signal is then reproduced as it is.

When the high-density digital signal is recorded and reproduced with reference to Figs. 2 (f) to (i), the peak equalization and waveform distortion in the playback equalizer 50 cannot be compensated for. In this case, as in the input digital signal (see FIG. 2A), in the case of the digital signal including the signal section 22 shorter than the predetermined reference interval, the output waveform of the playback equalizer 50 is shown in FIG. As shown in f), the peak point of the waveform does not coincide at the rising edge and the falling edge of the original recording signal, and the sine wave is biased to the other side due to the interference between data. Therefore, integrating the output waveform of the playback equalizer 50 in the integrator 62 is as shown in FIG. The inverted waveform is shown in FIG. 2 h.

The data detected by comparing the waveform amplified by the amplifier 64 and the inverted waveform by the comparator 66 has a waveform different from that of the digital signal originally input as shown in FIG.

While the error is determined slightly during data detection by waveform shaping and peak shift correction performed by the playback equalizer during digital signal reproduction, all peak shift and waveform distortions occurring in the head and tape are compensated for unless the playback equalizer is perfect during high density recording and playback. There is a problem that an error occurs because it is not possible.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to connect a record equalizer capable of varying the intensity of the recording current in consideration of peak shift and waveform distortion during high-density recording reproduction, thereby reducing errors in data detection. A high-density digital signal recording and reproducing apparatus is provided.

A feature of the recording and reproducing apparatus of the high density digital signal according to the present invention for achieving the above object is that a recording section for recording a high density digital signal on a magnetic recording medium and a digital signal recorded on the recording medium of the recording section are read from the head. A recording and reproducing apparatus for a high density digital signal, comprising a reproducing unit for detecting a digital signal, wherein the recording unit inputs the digital signal, and the interval between successive high logic levels or low logic levels of the input digital signal is a reference interval. A record equalizer for generating a window signal having a first logical level in a smaller section and a second logical level complementary to the first logical level in another section; A time delay for inputting the digital signal and delaying the digital signal to time-synchronize with the window signal; And inputting the delayed digital signal from the time delay, and inputting the window signal as a control signal to vary the recording current for recording the delayed digital signal when the window signal becomes a first logical level. Including a record amplifier that outputs the output to reduce the data error during playback.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of an apparatus for recording and reproducing a high density digital signal according to the present invention will now be described in detail with reference to the accompanying drawings.

3 is a block diagram of a high density digital signal recording and reproducing apparatus according to the present invention.

Here, a time delay 5 is connected between the digital signal input terminal and the record amplifier 10 to synchronize with the record equalizer 100, and an input terminal of the record amplifier 10 is connected to the time delay 5. The output of the record equalizer 100 is applied to the control stage of the record amplifier 10 in parallel with the time delay 5.

The head 20 is connected to the record amplifier 10, and the digital circuit recorded on the tape 30 is reproduced as in the conventional circuit. That is, a playback amplifier 40 is connected to the playback head 25, a playback equalizer 50 is connected to the playback amplifier 40, and the playback equalizer 50 detects playback active data. The data detector 60 is connected. The data detector 60 is composed of an integrator 62, an amplifier 64, and a comparator 66.

4 is a detailed circuit diagram of the record equalizer 100.

Here, three monostable oscillators 110 to 130 are connected in series to the digital signal input terminal. The signal of the data input terminal is input to the input terminal B11, which is the first input terminal of the monostable oscillator 110, and the input terminal A11 is grounded. A clear (CLR) terminal is connected to the power supply terminal (+ 5V), and is connected to the R / C terminal of the previous term (R1) connected to the power supply terminal (+ 5V), and the resistor (R1) and the R / C terminal. The capacitor C1 is connected to the contact point between the terminals.

A power supply terminal (+ 5V) is connected to the input terminal B12, which is the second input terminal of the monostable oscillator 110, and a digital signal input terminal is connected to the input terminal A12, which is the input terminal. The other terminal is connected to the same resistor R11 and capacitor C11 as the first input terminal.

An output terminal Q11 of the monostable oscillator 110 is connected to an input terminal B21 which is a first input terminal of the monostable oscillator 120, and a signal input from a digital signal input terminal is input to the input terminal A21. . The resistor R2 and the capacitor C2 are connected to the same terminal as the monostable oscillator 110.

An output terminal Q12 of the monostable oscillator 110 is connected to an input terminal B22 which is a second input terminal of the monostable oscillator 120, and a signal obtained by inverting a signal of the digital signal input terminal to the input terminal A22. Is input. The remaining terminals are the same as the monostable oscillator 110. The resistor R12 and the capacitor C12 of different values are connected to the same terminal.

The output terminal Q21 of the monostable oscillator 120 is connected to an input terminal B31 which is the first input terminal of the monostable oscillator 130, and the input terminal A31 is grounded. The output terminal Q22 of the monostable oscillator 120 is connected to the input terminal B32 which is the second input terminal, and the input terminal A32 is grounded. Here too, resistors R3 and R13 and capacitors C3 and C13 are connected to the same terminals as the monostable oscillators 110 and 120.

An output terminal Q31 of the monostable oscillator 130 and an OR gate which receives and outputs the output of the output terminal Q32 as an input are connected to each other, and the output is applied to the record amplifier 10.

The operation of the high-density digital signal recording and reproducing apparatus according to the present invention configured as described above will be described.

Referring to FIG. 3 and FIG. 4, when digital data is input, it is processed by the record equalizer 100 as follows.

Signal processing for the first input stage and the first output stage of each dominant monostable oscillator will be described.

Data input to the input terminal B11 of the monostable oscillator 110 (see FIG. 5 (a)) has pulses of the reference interval by the values of the resistors R1 and condenser C1 in response to the rising edge. The first reference signal is output (FIG. 5B). That is, the first reference signal illustrated in FIG. 5B is a signal for detecting the sections 54 where the high logic level sections of the input data are smaller than the reference intervals so that interference between the data occurs.

The output data of the monostable oscillator 110 (see FIG. 5 (b)) is input to the input terminal B21 of the monostable oscillator 120, and the first input data is input to the input terminal A21. In the monostable oscillator 120, pulses are generated when the output data of the monostable oscillator 110 is high level and where the input data is the falling edge (see FIG. 5 (c)).

The output data of the monostable oscillator 120 is input to the input terminal B31 of the monostable oscillator 130, and the pulse of a predetermined length depends on the values of the resistors R3 and condenser C3 at the rising edge of the output data pulse. Output (see FIG. 5 (d)).

Next, signal processing at the second input terminal and the second output terminal of each monostable oscillator will be described.

The monostable oscillator 110 outputs a second reference signal having pulses of reference intervals in response to the falling edge of the data input to the input terminal A12 which is the second input terminal (see FIG. 5 (e)). That is, the second reference signal illustrated in FIG. 5E is a signal for detecting the sections 52 where the low logic level sections of the input data are smaller than the reference intervals and thus interference occurs between the data.

In the monostable oscillator 120, the output data of the output terminal Q12 of the monostable oscillator 110 is input to the input terminal B22, and the first input digital signal is inverted through the inverter INV. When the output data of the monostable oscillator 110, which is inputted to A22), is high level, a pulse is generated at a portion where the inverted input digital signal is a falling edge (see FIG. 5 (f)). At this time, the width of the pulse is determined by the values of the resistor R12 and the capacitor C12.

In the monostable oscillator 130, at the rising edge of the output data pulse of the monostable oscillator 120, the resistor R13 and the condenser ( A pulse of a predetermined length is output in accordance with the value of C13) (see Fig. 5 (g)).

When the two output data, the first output data (figure 5 (d)) and the second output data (figure 5 (g)) of the monostable oscillator 130 are logically ORed at the OR gate, FIG. ) Waveform is output. In other words, the output waveform of the OR gate is a window signal, and the high / low logic level of the input data is smaller than the reference interval of the first and second reference signals so that interference between data occurs only in the sections 52 and 54. It means that a high level waveform is output.

In addition, the delayed data (see FIG. 5 (i)) through the time delay 5 for synchronization while the signal is processed by the record equalizer 100 is a window signal which is the output data of the OR gate OR. The degree of amplification depends on. As shown in FIG. 5 (j), when the input data is amplified twice in the record amplifier 10, the output pulse of the OR gate OR is amplified by about 1.5 times in the high level portion.

In the record amplifier 10, the window signal that is the output of the OR gate OR is amplified by about 1.5 times in the high level portion.

The record amplifier 10 reduces the magnitude of the write current of the digital signal temporarily input only at the moment when the window signal, which is the output of the OR gate OR, is high.

The output signal of the record amplifier 10 amplified differently according to the input data is applied to the head and recorded on the recording medium. The high-density digital signal recorded as described above has little recording current in the data in the sections 52 and 54 where the interference between the data is frequently generated during reproduction, resulting in less interference with each other and less error in data detection.

As described above, according to the digital signal recording and reproducing apparatus according to the present invention, when recording a high-density digital signal, the window signal detects in advance a section in which peak shift and waveform distortion due to interference between data are generated by the window signal. By varying and recording the intensity of the recording current in advance, there is an effect of reducing the error in the data detection process during reproduction.

Claims (2)

A recording and reproducing apparatus of a high density digital signal, comprising: a recording unit for recording a high density digital signal on a magnetic recording medium; and a reproduction unit for reading a digital signal recorded on the recording medium of the recording unit from a head and detecting a digital signal. And input the digital signal, and have a first logic level in a section in which a continuous high logic level or low logic level interval of the input digital signal is smaller than a reference interval, and in other sections, the digital signal is different from the first logic level. A record equalizer for generating a window signal having a complementary second logic level; A time delay for inputting the digital signal and delaying the digital signal to time-synchronize with the window signal; And inputting the delayed digital signal from the time delay, and inputting the window signal as a control signal to vary the recording current for recording the delayed digital signal when the window signal becomes a first logical level. And a record amplifier for outputting the signal to a high density digital signal. The recording and reproducing apparatus of the high density digital signal according to claim 1, wherein the reference interval can be arbitrarily varied.