KR930005600Y1 - Automatic scan device for magnetic recording track - Google Patents

Abstract

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Description

Magnetic recording track automatic scanning device

1 is a pattern diagram of a recording medium of a recording / reproducing system having four heads.

2 is a plan view of a drum mounted with four heads.

Figure 3 is an embodiment of an automatic scan device according to the present invention.

Figure 4 is a waveform diagram for explaining the operation of the automatic scanning device according to the present invention.

* Explanation of symbols for main parts of the drawings

10: mode selector 20: capstan motor

30: microcomputer 40: frequency generator

50 filter 60 60 peak detector

70: comparison unit 80: servo unit

The present invention relates to a self-recording track automatic scanning device in a recording / playback system, and more particularly to a magnetic recording track for scanning tracks with the same head as the head used during recording in a compact recording / playback system. It relates to a scanning device.

In the most typical VTR system of a recording / reproducing system, a compact drum used to reduce the size of a set to a small size and light weight typically uses four or more heads as shown in FIG.

In the case of reproducing the recorded data as described above, the tracking is controlled using an edge angle for compatibility with the existing TVR system. When the channel head CH1 of FIG. 2 is switched by the angle mounted on the drum, The probability of scanning CH1 or CH3 tracks in FIG. 1 is 50% and the likelihood of scanning CH2 or CH4 tracks in FIG. 1 when the channel head CH2 is switched is 50%, so if the channel head (CH1 or CH4) If you scan the CH3 (or CH4) track, the screen comes out, but jitter noise occurs due to head mismatch, resulting in screen degradation.

Accordingly, an object of the present invention is to solve the above problems, and when recording data on a recording medium, a pilot signal having a predetermined frequency band is recorded on CH1 and CH2 tracks, and the pilot signal is picked up during playback. It is to provide an automatic scanning device for the head to scan the track recorded by itself.

In order to achieve the above object, the present invention includes a capstan motor 20 for controlling the traveling speed and phase of a drum and a recording medium having at least two heads mounted thereon, and a servo unit 80 for controlling the operation of the capstan motor. A magnetic recording track automatic scanning device of a recording / playback system, comprising: a mode selecting section (10) for selecting a recording or reproducing operation mode, and the servo section (80) in selecting a recording mode by the mode selecting section (10) A frequency generator 40 for selectively generating first and second pilot signals f1 and f2 having different frequency bands to be recorded on a corresponding track of a recording medium according to a pulse generated by a drum rotation in Detecting means (50) for detecting different first and second pilot signals (f1, f2) from among signals picked up from the recording medium when the mode selection section (10) selects a playback mode; 1 and 2 A recording mode by the comparison means 70 and the mode selection unit 10 for comparing the signal output from the detection means 50 with a predetermined reference value to determine whether or not the lot signals f1 and f2 have been detected. When selected, the first and second pilot signals f1 and f2 are transmitted to the frequency generator 40 by the switching pulse of the head detected by the pulse generator PG signal generated by the servo unit 80. And a microcomputer 30 for controlling the speed of the capstan motor 20 through the control of the servo unit 80 according to whether or not the pilot signal is detected by the detection means 50 during the regeneration control. It is characterized by including.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 shows a magnetic recording track automatic scanning apparatus according to the present invention, a head CH for recording data on a recording medium or reproducing a recorded signal, and a microcomputer 30 for controlling the overall operation of the apparatus. And the capstan motor 20 and the microcomputer 30 to control the phase of the capstan motor 20 and present to the microcomputer 30 by a PG (pulse generator) signal generated from a drum (not shown). Servo pilot signals f1 and f2 having different frequency bands are received by receiving the arbitrary control signals C1 and C2 output from the servo unit 80 and the microcomputer 30 during recording to inform the head in the switched-on state. A frequency generator 40 for generating, a filter unit 50 serving as a detection means for detecting pilot signals f1 and f2 having different frequency bands among the signals reproduced from the recording medium in the reproduction mode, and the filter Pilot signals f1 and f2 output from the unit 50 Peak value of the pilot signal f1 and f2 output from the peak detector 60 and the preset reference voltage Vref are compared with each other. Comparing unit 70 for supplying to the input ports (P1, P2) to output a control signal for the rotational speed of the capstan motor 20 of the microcomputer (30).

The operation of the magnetic recording track automatic scanning device having the above configuration will be described below.

First, the process in which the pilot signals f1 and f2 are recorded in the tracks of CH1 and CH2 when recording arbitrary data on a magnetic tape as a recording medium will be described with reference to the waveform diagram shown in FIG. From the drum pulse generator (not shown) in the servo unit 80 shown in Fig. 1, a pulse having a cycle of dividing the pulse DPG according to drum rotation by using a divider (not shown) When (A) and the pulse B, which is divided into 1/2 of the pulse A again, are generated, the microcomputer 30 outputs a control signal from the frequency generator 40.

That is, since the switching of CH1 occurs first after the DPG (Drum Pulse Generator) signal is generated in the waveform diagram shown in FIG. 4, it is recognized that CH1 is switched when the pulses A and B are both "high". The control signal is output to the frequency generator 40 so that the pilot signal f1 is generated. When the pulse A is in the "high" state and the pulse B is in the "low" state, it is recognized that CH2 is switched. The control signal is output to the frequency generator 40 so that the signal f2 is generated.

Each pilot signal f1, f2 output from the frequency generator 40 is recorded in the corresponding track of the recording medium via the mode selector 10 and the head CH. For the sake of convenience, it is recorded on the corresponding track of the recording medium via the head CH. Here, for convenience, the head CH is represented as Hannah. However, when the pilot signal f1 is generated, the head CH is recorded on the recording medium through the CH1 head of FIG. 2, and when the pilot signal f2 is generated, it is recorded through the CH2 head. Recorded on the medium.

The microcomputer 30 determines that the CH3 head of FIG. 2 is in an on state when the signal (A) of FIG. 4 generated by the servo unit 80 is low and the signal (B) is low. Is low and the signal (B) is low, it is determined that CH4 is on, or when tracking is performed by the heads of CH3 and CH4, the frequency generator 40 does not record any pilot signals, so the frequency generator 40 generates no frequency. I never do that.

By controlling the recording mode, the mode selector 10 is switched to the playback mode in order to play back tapes in which pilot signals f1 and f2 having different frequency bands are recorded on the corresponding tracks of CH1 and CH2. Look at the relationship between the states.

In the regeneration mode, the track corresponding to the CH1 head and the CH3 head and the CH2 head to the CH2 and CH4 head are tracked by the ratio of 50% as described above by the phase control of the general capstan motor 20. Can be scanned.

That is, in the case of the CH1 head, the composite video signal including the pilot signal f1 and the composite video signal without the pilot signal f1 may be picked up.

In the case of the CH2 head, a composite video signal including the pilot signal f2 and a composite video signal without the pilot signal f2 may be picked up.

First, when the composite video signal including the pilot signal f1 is picked up through the head CH in a section in which both the (A) signal and the (B) signal are "high" as shown in FIG. The filter unit 50 is applied to the filter unit 50 through the selection unit 10. The filter unit 50 removes the composite video signal applied through the filter 50A and outputs only the pilot signal f1. However, since the filter 50A has a cutoff frequency port so that the pilot signals f1 and f2 can be detected, a signal other than the pilot signal f1 is output to the signal output from the filter 50A. Only the pure pilot f1 is separated and detected and output. Here, the filter 50A may use a low pass filter and the filter 50B may use a band pass filter.

The pilot signal f1 output from the filter unit 50 is supplied to the peak detecting unit 60A of the peak detecting unit 60 to detect and apply the maximum level of the pilot signal f1 to the comparing unit 70. The comparison unit 70 compares the maximum level voltage of the pilot signal f1 applied through the comparison unit 70A with the preset reference voltage Verf. At this time, since the reference voltage Verf is set so that the comparator 70A always outputs the "high" signal when the pilot signal f1 is applied, the input port P1 of the microcomputer 30 is always supplied with the "high" signal. do.

When the "high" signal is applied through the input port P1, the microcomputer 30 senses that the CH1 track is being scanned while the CH1 head is switched, and the speed of the capstan motor 20 through the servo unit 80 is detected. It is controlled so as to keep the normal playback.

On the other hand, when the pilot signal f1 is not detected through the filter unit 50 and the peak detector unit 60 described above when the CH1 head scans the corresponding track of the recording medium, the comparison means 70A is reversed as described above. Always output a "low" signal. Accordingly, the microcomputer 30 determines that the track corresponding to the CH3 head is being scanned by the "low" signal applied through the input port P1, and the capstan motor 20 is connected to the CH1 by the servo unit 80. Acceleration control to be located on the track corresponding to the head.

Meanwhile, the process of controlling the rotational speed of the capstan motor 20 to scan the track corresponding to the CH2 head is the same as the process of controlling the CH1 head to scan the track corresponding to CH1.

That is, the composite image signal applied through the mode selection unit 10 is applied to the filter unit 50 and only the pilot signal f2 is detected through the filter 50A. However, as described above, the filter 50A is capable of detecting both pilots f1 and f2 so that the signal output from the filter 50A is not a pure pilot signal f2.

Accordingly, the pure pilot signal f2 is detected through the dedicated filter 50C of the pilot signal f2, and the maximum value level is detected through the peak detection means 60B of the peak detection unit 60 to detect the maximum value level. It outputs to the comparison means 70B.

When the pilot signal f2 is detected like the comparison means 70A, the comparing means 70B sets the reference level Vref to always output "high", so that the microcomputer 30 sets "high" to the P2 input terminal. Output Due to this, the microcomputer 30 outputs a control signal through the servo unit 80 so that a normal regeneration operation is performed.

However, if the pilot signal f2 is not detected through the filter unit 50 and the peak detector unit 60, the comparator 70B of the comparator unit 70 always outputs "low", so that the microcomputer 30 currently displays CH4. It is determined to scan the track corresponding to the control unit 80 to output the control signal to accelerate the capstan motor 20 to the servo unit (80).

Acceleration control of the capstan motor 20 is performed until the CH2 track is scanned. When the CH1 and CH2 tracks are controlled in this way, the next CH3 and CH4 are automatically controlled, and the four CHs attached to the drum (not shown) are recognized during playback. (A) and (B) of FIG. 4, which are divided signals for DPG provided in 80).

The automatic scanning device operating as described above is adopted in the compact recording and reproducing apparatus, so that a good quality screen can be obtained by scanning the track recorded by the self during playback.

Claims (4)

Automatic recording of magnetic recording tracks in a recording and reproducing system, comprising a capstan motor 20 for controlling the traveling speed and phase of a recording medium and a drum having at least two heads mounted thereon and a servo unit 80 for controlling the operation of the capstan motor. In the apparatus, a mode selecting section (10) for selecting a recording or reproducing operation mode, and a pulse generated by the drum rotation in the servo section (80) when the recording mode is selected by the mode selecting section (10). Accordingly, by the frequency generator 40 and the mode selector 10 for selectively generating the first and second pilot signals f1 and f2 having different frequency bands to be recorded on the corresponding tracks of the recording medium. Detecting means 50 for detecting different first and second pilot signals f1 and f2 among the signals picked up from the recording medium when the reproduction mode is selected, and the first or second pilot signals f1 and f2, respectively. ) Was detected The pulse generator generated in the servo unit 80 when the recording mode is selected by the comparison means 70 and the mode selection unit 10 for comparing the signal output from the detection means 50 with a predetermined reference value for determining. And controlling the frequency generator 40 to generate the first and second pilot signals f1 and f2 by the switching pulse of the head detected by the (PG) signal. And a micom (30) for controlling the speed of the capstan motor (20) by controlling the servo unit (80) according to whether or not the pilot signal is detected by (50). The first filter (50A) of claim 1, wherein the detecting means (50) has a cutoff frequency band that can include both the first and second pilot signals (f1, f2) among the picked-up signals. A second filter 50B for detecting only the first pilot signal f1 from the signal output from the first filter 50A and the second pilot signal (from the signal output from the first filter 50A). and a third filter (50C) for detecting only f2). The servo unit (100) of claim 1, wherein the microcomputer (30) controls the capstan motor (20) to perform a normal regeneration operation when it is determined that the pilot signal is detected by the output signal of the comparing means (70). 80) outputs a control signal, on the other hand, if it is determined that the pilot signal has not been detected, the magnetic recording track auto-scan, characterized in that for controlling the servo unit 80 to accelerate the speed of the capstan motor 20 Device. The apparatus of claim 1, wherein the automatic recording track scanning device further includes a peak detector (60) for detecting the maximum level of the signal output from the detection means (50) and outputting the detected level to the comparison means (70). A magnetic recording track automatic scanning device.