JPS63121104A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To automatically and instantly check heads, and to continue recording except a case when both heads are abnormal, by switching a mode based on a clog detecting means and its result, and recording a signal with a second head tentatively. CONSTITUTION:First and second heads 2 and 2', and 4 and 4' are set at reproducing states immediately as soon as the second magnetic heads 4 and 4' detect clog, and the signal recorded by rotary erasing heads 6 and 6' is reproduced. And an ordinary recording mode is continued when only the first recording heads 2 and 2' reproduce the signal, simultaneously, the recording is performed tentatively with a simultaneous monitoring head when only the second magnetic heads 4 and 4' for simultaneous monitoring, reproduce the signal, and a mode is returned to an ordinary recording mode when the first heads 2 and 2' recover. In such a way, it is possible to apply an optimum processing for abnormality such as the clog, etc., automatically and instantly, by which a wasteful time can be prevented from being generated. Also, since the recording is continued unless both recording and monitoring heads are abnormal, it is possible to remarkably reduce frequency to lose a recording timing in an important scene.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic recording and reproducing device having a rotating magnetic head such as a helical scan video tape recorder.
In particular, the present invention relates to a magnetic recording and reproducing apparatus configured to perform simultaneous monitoring in a recording mode using a magnetic head that is displaceable in the track width direction and is housed separately from a normal recording and reproducing head.

2. Prior Art As a conventional magnetic recording/reproducing device, the present inventors filed a patent application in 1983.
There is a device proposed in the specification of No. 0-209205. It records video signals and time-compressed audio signals using a recording/reproducing head fixed to a rotating drum, and simultaneously monitors the recorded signals using a movable magnetic head attached to a bimorph. During playback, the movable head is moved to the audio signal advance playback position to adjust the timing.

Problems to be Solved by the Invention However, with the above configuration, even if an abnormality such as clogging occurs in the simultaneous monitoring, the device itself does not have a processing function and a human must deal with the problem. Also, even if you can observe an abnormality, you cannot immediately determine what it is, whether it is in the recording system, playback system, or both, and the only way is to rewind the tape once and play it back.This results in a loss of time and misses the recording timing. There was a serious problem. Furthermore, even if the simultaneous monitor side was normal, it did not have a recording function and could not be recorded even in an emergency.

In view of this, the present invention provides a novel magnetic recording/reproducing device that automatically and immediately checks whether an abnormality such as a clogging occurs on the recording side or the monitor side, and continues recording unless both heads are abnormal. The purpose is to provide.

Means for Solving the Problems The present invention provides a first magnetic head for recording and reproducing signals, a second magnetic head for simultaneously monitoring during recording, a rotary erasing head capable of recording signals, a clogging detection means, and a second magnetic head for simultaneously monitoring during recording. A control means that switches modes based on the results, and a second
This is a magnetic recording/reproducing device consisting of means for recording signals with a head.

Effects of the present invention As soon as the second magnetic head detects clogging, the first magnetic head detects clogging. Set the second head to the playback state, - Play back the recorded signal with the rotary erase head, and when only the first head for recording plays back the signal, continue the normal recording mode, and set the second head for simultaneous monitoring. When only magnetic head 2 is playing, record temporarily with the simultaneous monitor head,
When the first head recovers, it returns to normal recording mode.

Embodiment FIG. 1 is a plan view showing the arrangement of a magnetic head of a magnetic recording/reproducing apparatus in an embodiment of the present invention. In FIG. 1, a first magnetic head 2 is mounted on a rotating drum 1 rotating in the direction of arrow a.
, 2' (180 facing each other) are fixed and record or reproduce data on the magnetic tape 3 running in the direction of the arrow. A second magnetic head 4.4 is arranged with a trailing amount α from this.
' (180 facing each other) are provided on bimorph plates 6, 6' made up of piezoelectric elements, and are movable in the track width direction. Furthermore, rotary erasing heads 6 and 6' (opposed to each other at 180) are fixed at positions preceding the first magnetic head 2. Each magnetic head has a predetermined height difference H1, H2 as shown in FIG. 2, and is configured to accurately scan the same track on the tape pattern. Also the third
The figure shows connections between each magnetic head and a signal processing circuit. In FIG. 3, the first magnetic head 2.2' is connected to the recording signal processing circuit, the clogging detection circuit B, and the recovery detection circuit by switching the changeover switch 7, and the second magnetic head 4.4 is connected to the recording signal processing circuit, the clogging detection circuit B, and the recovery detection circuit.
' are respectively connected to the reproduction signal processing circuit, the clogging detection circuit A, and the recording signal processing circuit by switching the changeover switches 8.9. Further, the rotary erasing head 6°e' is connected to the erasing signal generating circuit and the recording signal generating circuit, respectively, by switching the changeover switch 1o.

Further, the signals from the clogging detection circuits A and B and the clogging recovery detection circuit are supplied to a control signal generation circuit, and the bimorph plate 6 is provided with the above-mentioned switches and the second magnetic head 4.4'.
．． 5', the phase of the rotating drum is switched. The first position of the drum phase to be switched here is the first magnetic head 2.
, 2' are the positions where a regular tape pattern is formed on the magnetic tape 3, and the second position is the position where the second magnetic head 4 is located.
．． 4' is the position where a regular tape pattern is formed.

The bimorph control signal is switched to four modes: simultaneous monitoring, audio advance playback, and emergency recording, and FIG. 4 shows the signal waveform of one channel. In Fig. 4, the signal for simultaneous monitoring is supplied after all servo systems have stabilized at the start of recording, and first a signal whose level changes by a fixed amount every two tracks is supplied, and the second magnetic head at that time reproduces. The outputs are compared, and the control signal at the highest output is determined as the optimum signal and used as the subsequent reproduction tracking signal. In addition, as for the signal during advance playback, a constant signal for +2 track pitches is supplied at the start of playback, and after each servo system is all stabilized, the same control signal as during the simultaneous playback is supplied with the +2 track pitch position as a reference, and the optimal Provide a constant optimal tracking signal after checking the position. Also, during emergency recording, the signal for two tracks is added to the optimal signal for simultaneous monitoring and is immediately supplied. Therefore, the second servo phase described above
The position , as shown in FIG. 6, is the sum of the correction amount α due to the head mounting angle and the H deviation amount β for two tracks.

The confirmation of the optimal tracking position during simultaneous monitoring or advance playback is repeated at regular intervals to ensure tracking accuracy during continuous long-term recording or playback. Further, each of the two opposing heads is switched by a dedicated switching circuit (not shown) for each field.

The operation of the magnetic recording/reproducing apparatus of this embodiment configured as described above will be explained below.

First, in the recording mode, switch 7 in FIG. 3 connects the recording signal processing circuit and the first magnetic head 2.2', and switch 8.9 connects the reproduction signal processing circuit and the clogging detection circuit to the second
magnetic heads 4, 4' are connected. and switch 1o
connects the erasing signal generating circuit and the rotating erasing head 6.6', the bimorph control signal is set to the simultaneous monitoring position, and the drum phase is set to the first position. Then, during recording, for example, if a clog occurs in the first magnetic head 2, 2' or the second magnetic head 4, 4' and the clog detection circuit A is activated, the control signal generation circuit confirms the abnormal head. Switch each head and circuit to . Next, its operation will be explained. First, the switch 7 switches the first magnetic head 2.2' to the clogging detection circuit B, and the switch 1o connects the rotary erasing head 6.6' to the recording signal processing circuit. The signals recorded on the magnetic tape 3 by the rotary erasing head 6.6' are transferred to the first and second magnetic heads 2.2.
', 4°4', recording side head (first magnetic head 2°2' or reproducing side (second magnetic head 4.4')
Determine which abnormality is occurring. If the reproducing head is clogged, the normal recording mode is immediately returned to continue recording. However, if the recording head is clogged, the reproducing head must perform emergency recording, and switching to this operation will be explained next. As soon as the switch 8 detects that it is the recording head, the second magnetic head 4.4' is switched to the recording signal processing circuit, the drum phase is set to the second position, and the Matabimorph 6, 6' is activated for emergency recording. Start the emergency recording that supplied the signal. Then, the switch 7 connects the first magnetic head 2,
2' is connected to a clogging recovery detection circuit to monitor clogging recovery of the first magnetic head 2.2', which is the original recording head, at the same time as emergency recording. To enable this monitoring, the second magnetic heads 4, 4' for emergency recording are moved from the simultaneous monitoring position to the audio signal advance playback position two tracks earlier than the original recording head position. Due to mechanical misalignment, there is a misalignment in the positional relationship with the control or near-audio fixed head (not shown). Therefore, this record is distinguished from the original record and is considered an emergency record. This positional deviation is caused by the second magnetic heads 4, 4.
This can be solved by setting the magnetic heads 4 and 4' to the simultaneous monitoring position, but recording with the mechanically unstable second magnetic heads 4 and 4' is not preferable in terms of pattern accuracy such as video track linearity, and the original recording head is In this embodiment, the above-mentioned emergency recording method is used because it is preferable to immediately return to recording using the original head once the clogging is recovered, and because recovery cannot be monitored at the simultaneous monitoring position. However, recording at the simultaneous monitor position has the advantage of eliminating the need for a full-width fixed erase head, since unnecessary signals can be erased using the rotating erase head and then recorded using the simultaneous monitor head.

When the clogging is recovered, the clogging recovery detection circuit detects it, and the control circuit returns the connection between each head and the circuit, the servo signal, and the bimorph signal to the normal recording mode, and continues recording. Also, if the recording/playback head is clogged, immediately clean the device! Move to 3TOP mode.

Further, in the reproduction mode, the signal supply to the rotary erasing head 6, 6' is stopped, and in the normal reproduction mode, the video signal is reproduced by the first magnetic head 2, 21, and the second magnetic head 4,
4' pre-reproduces the audio signal two tracks before.

Also, during special reproduction, only the video signal is reproduced by the second magnetic heads 4, 4'.

As described in detail, according to the present invention, if an abnormality occurs during simultaneous monitoring, it is immediately checked whether the head is on the recording side or the monitor side, and if the monitor side is clogged, the normal recording mode is continued. If the recording side is clogged, the head on the monitor side starts emergency recording, monitors the original recording head for recovery from the clog, and returns to normal recording mode as soon as the clog recovers. Optimal measures can be taken automatically and immediately for abnormalities such as blockages, and time loss can be prevented. Additionally, since both the recording and monitor heads continue recording unless there is an abnormality, the frequency of missing recording timing for important scenes is greatly reduced. Furthermore, since the recording head is configured to immediately return to the normal recording mode when the original recording head recovers, a highly accurate recording signal can be ensured, which has a great practical effect.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a rotating drum of a magnetic recording/reproducing device according to an embodiment of the present invention, FIG. 2 is a configuration diagram of a magnetic head of the embodiment, and FIG. 3 is a diagram showing the configuration of each head and a signal processing circuit of the embodiment. FIG. 4 is a waveform diagram showing signals supplied to the bimorph plate of the same embodiment. FIG. 6 is a pattern diagram showing recording track positions in normal recording mode and emergency recording mode. 1... Rotating drum, 2, 2'-... First magnetic head, 3... Magnetic tape, 4, 4'
...Second magnetic head, 5, 5'-...
- Bimorph plate, 6, 6'--Rotating erasing head. Name of agent: Patent attorney Toshio Nakao and 1 other person
1 Figure 2

Claims (3)

[Claims] (1) A first magnetic head that records a video signal and a time-axis compressed audio signal on an inclined track, and a first magnetic head that constantly monitors the signals recorded by the first magnetic head in the normal recording mode, and in the playback mode, A displaceable second magnetic head for pre-reproducing audio signals and an erasing head are provided at a position preceding the first magnetic head, and when the second magnetic head detects an abnormality during normal recording mode, the first and second magnetic heads are disposed. The second magnetic head is switched to the reproduction mode and a recording signal is supplied to the erasing head, and when the first magnetic head reproduces the signal recorded by the erasing head, recording is continued with the first magnetic head and the second magnetic head is switched to the reproduction mode. 1. A magnetic recording and reproducing apparatus characterized in that when a second magnetic head performs reproduction, the mode is switched to a recording mode using a second magnetic head, and when there is no signal from both heads, the mode is switched to a stop mode. (2) When the second magnetic head reproduces the signal recorded by the erasing head, the second magnetic head is switched to the recording mode, the first magnetic head is switched to the reproduction mode, and the second magnetic head is preceded by the second magnetic head. 2. The magnetic recording and reproducing apparatus according to claim 1, wherein the magnetic recording and reproducing apparatus is configured to move the drum to a reproducing position and switch the drum phase to a position where the second magnetic head forms a regular tape pattern. (3) The magnetic recording and reproducing apparatus according to claim 2, wherein the first magnetic head waiting in the reproducing mode is configured to return to the normal recording mode after reproducing the signal.