JPS5936339B2 - Control signal eraser - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides control signals recorded on a magnetic recording medium.
The present invention relates to a device for automatically operating a magnetic recording/reproducing device, and particularly to a device for independently erasing a control signal at an arbitrary point in time.

In this type of magnetic recording/reproducing apparatus, it often happens that the control signals are replaced, or the program signal is deleted leaving only the control signal, and a new program signal is recorded. However, in many cases, the track width for recording 81-car signals is narrower than the width of the program signal track, and the portion where control signals are recorded is often in a specific section. It is difficult to erase it completely.

In other words, when a special head for erasing control signals is provided, it is not only difficult to align the tracks, but also when accurately erasing only a specific part where the control signal is recorded, the part where the control signal is recorded is difficult. It was very troublesome to align the front of the erase head. Furthermore,
By providing a special erase head, great care must be taken in selecting the location where the erase head is installed, and it places a load on the magnetic recording medium's running system.
This has problems such as not only high costs but also harmful effects.

Therefore, in the present invention, when erasing a recorded control signal, the above-mentioned problems are solved by using a circuit configuration that allows a large-amplitude alternating current signal or a direct current to flow directly to the control signal recording/reproducing head. It was completely resolved.

In other words, since the control signal recording/reproducing head itself erases without providing a separate erasing head, track alignment becomes unnecessary. Once you have confirmed the position of the tape, you can move on to the erasing operation without changing the tape feeding position and erase only the necessary parts. Next, a more detailed explanation will be given based on a block diagram showing one configuration example of the present invention.

In the figure, reference numeral 1 indicates a magnetic head for recording and reproducing control signals.

2 is a control signal erasing switch, which has a common contact C and switching contacts a and b.

3 is an erase current supply source, and 4 is a control signal recording/reproduction changeover switch, which has a common contact f and changeover contacts d and e.

Reference numeral 5 denotes a control signal regenerative amplifier, which has a control signal output terminal 9.

6 is a control signal recording amplifier, T is a control signal generation source, and 8 is a bias oscillation circuit.

Reference numeral 10 denotes a control section of the magnetic recording/reproducing apparatus, which, although not shown, operates the mechanical section of the magnetic recording/reproducing apparatus and various switches to change the magnetic recording/reproducing apparatus into an arbitrary operating state.

Reference numeral 11 denotes an erase mode preset switch for erasing the control signal. When the control section 10 is preset to the erase mode by this switch 11, the arrival of the control signal supplied from the control signal output terminal 9 causes the control section to 10 is automatically converted to the erase mode.

Reference numeral 12 denotes an erase switch driving section, which drives the erase switch 2 when the control section 10 is switched to the erase mode.

Next, the circuit operation will be explained.

The connection state of each switch shown in the figure shows the circuit connection when recording a control signal, and the explanation will start from this state. One end of the coil of the recording/reproducing magnetic head 1 is grounded, and the other end is connected to a common contact C of the thorax signal erasing switch 2. , are connected to the bias oscillator 8.

Although not shown in the drawings, if the magnetic recording medium is moving in contact with the recording/reproducing magnetic head 1 in this state, a control signal generated as necessary from the control signal generation source T passes through the recording amplifier 6 and biases the magnetic recording medium. The signal is superimposed on the bias signal supplied from the oscillator 8, is supplied to the magnetic head 1, and is recorded on the magnetic recording medium. In order to reproduce the control signal recorded as described above, the recording/reproducing switch 4 may be switched so that the common contact f and the switching contact d of the recording/reproducing switch 4 are connected.

The control signal recorded on the magnetic recording medium is transmitted to the magnetic head 1.
After being regenerated by the regenerating amplifier 5, an output signal is output to the control signal output terminal 9.

A signal appearing at the control signal output terminal 9 is applied to the control section 10 and used to perform various automatic operations as necessary. Next, the erase operation will be explained. In this case, no matter what state the recording/reproducing switch 4 is in, if the erasing switch 2 is operated so that the common contact C and the switching contact a of the erasing switch 2 are connected, the magnetic head 1 can be connected to the reproducing amplifier 5, the recording It is separated from the amplifier 6 and the like and connected to the erase current supply source 3. Therefore, an erasing current flows through the magnetic head 1, erasing the signal recorded on the magnetic recording medium. In this case, the erase current supply source 3 may be an independent oscillation circuit, but
There is no problem even if the bias oscillation circuit 8 is shared. Furthermore, the erase current supply source 3 may be a direct current supply source.
That is, in general, when erasing is performed using direct current, erasure noise is generated, but there is no problem at all when recording and reproducing the ram signal. When searching for a portion where a control signal is recorded and performing an erasing operation, the following operation is performed. First, the control signal is set to a reproducing state, and when a control signal appears at the pedestal signal output terminal 9, the necessary portion can be erased by immediately switching the erase switch 2 while the reproducing state is maintained. It is also possible to automatically set the stop operation state once upon arrival of the control signal, and then set the playback state again after switching the erase switch 2. Furthermore, if all erasing operations are to be performed automatically, the controller 10 is preset to the erasing mode by the erasing mode preset switch 11. In this case, when a control signal appears at the control signal output terminal 9, the control section 10 automatically switches to the erase operation state, and as a result, a signal is applied to the erase switch drive section 12 to switch and drive the erase switch 2. . As a result, the Fhl leg signal is automatically erased in the recording/reproducing magnetic head at the same time as the position of the control signal is searched in the reproduction mode. As described above, according to the present invention, since no special erasing head is used when erasing only the control signal, there is no need for track alignment, and the effort required for adjusting the magnetic recording medium running system is eliminated. Since the control signal recording/reproducing head itself performs erasing, it is very easy to locate a partial control signal recording portion and to perform partial erasure.

Furthermore, it is very convenient to be able to perform the erasing operation at any time each time the control signal erasing switch is operated, regardless of the recording/reproducing mode. Furthermore, the operation from searching to erasing the control signal recording portion can be performed accurately either automatically or manually, and the circuit configuration for this purpose is extremely simple.

BRIEF DESCRIPTION OF THE DRAWINGS The figure is a block diagram of a main part of a swinging leg signal erasing device according to an embodiment of the present invention. 1... Recording/reproducing head, 2... Control signal erase switch, 3... Erase current supply source,
4...Record/playback selector switch, 5...
Reproducing amplifier, 6... Recording amplifier, T...
...Control signal generation source.

Claims (1)

[Claims] 1. A recording/reproducing magnetic head for recording and reproducing control signals is provided with a recording/reproducing selector switch for switching and connecting it to a recording/reproducing circuit, an erasing current supply source, and a control signal erasing switch, and the operation of the control signal erasing switch is provided. A control signal erasing device characterized in that, at times, the magnetic head is electrically disconnected from the recording/reproducing circuit and connected to the erasing current supply source.