JPS6213206Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a spiral magnetic recording and reproducing device.

A spiral magnetic recording and reproducing machine is a device in which a magnetic head moves in a spiral manner to scan the magnetic surface of a magnetic sheet placed on a turntable, thereby recording and reproducing information. Next, one example will be described. The external appearance of this spiral type magnetic recording/reproducing machine is shown in FIG. A magnetic sheet 3 is fixed on the top plate 2 of the outer box body 1 of this regenerator, and the magnetic sheet 3 is attached to the top plate 2 by three relatively short ruler pins 4. placed in the correct position. A transparent press plate 5 is hinged to one side edge of the outer box body 1, and this press plate 5 presses the magnetic sheet 3 onto the top plate 2. A large circular hole 2a is bored in the top plate 2, and a decorative plate 6 that is substantially integrated with a turntable to be described later is provided in the circular hole 2a. This decorative board 6 has
A groove 7 is cut in the radial direction, and a magnetic head 8 mounted on a turntable 17 (see FIG. 2) projects from the inside of the groove 7. The magnetic head 8 rotates together with the turntable 17, and during this rotational movement, it gradually advances toward the center of the turntable by a feed screw, which will be described later. Therefore, as the turntable 17 rotates, the magnetic head 8 moves toward the center of rotation while tracing a spiral trajectory. magnetic head 8
is brought into contact with the recording/reproducing surface of the magnetic sheet 3 and slid in a spiral manner to record and reproduce audio. During recording and playback, rotation of the turntable is started and paused by operating the playback button 9, fast-forwarding of the turntable 17 is carried out by operating the fast-forwarding button 11, and reverse operation is carried out by operating the reverse button 12. . Also, the recording action is performed by operating the record button 13 and the playback button 9 together, and by operating each of these buttons,
Recording, playback, fast forwarding, and reversing operations are performed by mechanisms not shown. Reference numeral 14 indicates a power switch, 15 a volume control knob, and 16 a counter that displays the number of revolutions of the turntable.

A turntable 17, to which the decorative plate 6 is integrally attached, is pivotally mounted on a shaft 18, as shown in FIG. The base end of this shaft 18 is fixed to a main mounting plate (not shown). A helical gear 21, which is substantially integral with the cylindrical body 19, is fixed to the shaft 18 by a screw 22, and a helical gear 23 is meshed with the gear 21. The feed screw 24 with the helical gear 23 attached has one end attached to the turntable 17 with screw 2.
Attach the other end to the support member 26 fixed to the support member 2 at
The turntable 17 is supported parallel to the horizontal plane by being supported by the turntables 7, respectively. The turntable 17 is rotated in the direction of arrow A by a drive source (not shown), and the helical gear 23 is rotated in the direction of arrow B by this rotational operation. The rising portion 28a of the support member 28 fixed to the turntable 17 and the bent piece 28
There are two guide rods 29a, 29c between the guide rods 29a, 28c.
9b are attached respectively. Guide rod 29
A moving table 31 is attached to a and 29b,
An elevating plate 35 on which a magnetic head 8 is fixedly fitted is loosely fitted into two guide rods 32 and 33 erected on a movable table 31. An extensible spring 34 is provided between the elevating plate 35 and the movable table 31, and the elasticity of the spring 34 gives the elevating plate 35 a rising habit. However, this upward movement of the elevating plate 35 is prevented by one end 35a of the elevating plate 35 coming into contact with an adjustment lever (not shown).

On the other hand, the movable table 31 has an engaging arm 36 having an L-shaped plane and having a knife edge 36a at the free end.
The base portion 36b of is fixed. This engagement arm 36
The knife edge 36a is engaged with the above-mentioned feed screw 24. The feed screw 24 is connected to the turntable 1
7 in the direction of arrow A, the helical gear 23
At the same time, it rotates in the direction of arrow B. As a result, the rotation of the feed screw 24 gradually feeds the movable table 31 in the radial direction via the knife edge 36a.
Therefore, in FIG. 2, as the turntable 17 rotates, the magnetic head 8 moves toward the center of the turntable 17 while drawing a spiral trajectory.

In this manner, the magnetic head 8 moves in a spiral manner, whereby the magnetic sheet 3 is scanned and recording or reproduction is performed.

The above is an overview of the spiral magnetic recording and reproducing machine. The width of the magnetic track formed in a spiral manner on the magnetic surface of the magnetic sheet by the magnetic head 8 is 0.8 mm.
The gap between track widths is 0.45mm. Therefore, one pitch has a width of 1.25 mm. With this track width, the magnetic head scans the magnetic surface of the magnetic sheet while the turntable rotates approximately 30 times, ie, while the turntable rotates 30 times. Furthermore, since it takes about 8 seconds for one turn of the turntable, the magnetic sheet 3 can record or playback for about 4 minutes.

However, the spiral magnetic recording and reproducing machine configured in this way does not move the recording medium as in the case of records and magnetic tapes, but instead fixes the magnetic sheet 3, which is the recording medium, and moves the magnetic head 8. Since magnetic recording and reproduction are performed by moving the magnetic head in a spiral manner, the mechanism for moving the magnetic head becomes very complicated as described above. For this reason, most conventional magnetic sheet recording/playback machines are not equipped with a degaussing device in the main body of the recording/playback machine, and when erasing the magnetic recording on the sheet, a degaussing device such as a separate bulk eraser is required. It was deleted with Furthermore, if a degaussing device is added to the main body of the recording/playback device, it must be installed in front of the recording/playback head in the direction of travel, and it must also be able to move in an accurate spiral. However, the mechanism of moving the two heads, the recording/playback head and the erase head in a spiral along the same trajectory and moving them respectively toward the center of rotation, is not only extremely troublesome, but also involves the recording/reproducing head. A dedicated electric circuit for the erase head, which is completely separate from the read head, is required. Therefore, 3 circuits or 4
A sliding device for the circuit is required, and this also involves complicated technical problems such as crosstalk between circuits.

However, a recording/playback machine without a degaussing device is very inconvenient, but if it is equipped with a degaussing device, it can perform the same functions as a tape recorder.

An object of the present invention is to provide a spiral magnetic recording and reproducing device that has a degaussing function added using a simple mechanism.

That is, when a recording is made and then played back, the magnetic head must be returned to its original position, in other words, to the starting position. Moreover, when returning, if the turntable on which the magnetic head is attached is rotated in the opposite direction, the magnetic head will move in the opposite direction along the trajectory traveled during recording. Therefore, when returning, if an erasing current is applied to the previous recording/playback head, the recording on the recording band will be demagnetized. The present invention cleverly takes advantage of the fact that when the magnetic head returns to its starting position after recording, it can follow the same trajectory in reverse as when recording, and at this time, an erasing current is applied to eliminate unnecessary recordings. It is designed to demagnetize it.

In this way, the three functions of recording, playback, and erasing can be performed with only one head device and sliding device, so it is very easy to add a degaussing function to a conventional spiral type magnetic recording/playback device. I can do it.

The present invention will be explained below with reference to figures. FIG. 3 is a block diagram of the electric circuit during recording and erasing of the spiral type magnetic recording and reproducing apparatus of the present invention. During recording, the output of the microphone M is amplified by the amplifier Am ₁ , and this output is further amplified by the amplifier Am ₂ and sent to the recording/playback heads R, P, and H via the trap circuit _T0 . It will be done. An alternating current bias is applied to the recording/playback heads R, P, and H from an oscillator OSC via a transformer T. A switch _S0 that changes the oscillation output is inserted in the secondary side of the transformer T. During recording, this switch _S0 is switched to the contact _A0 side, and the appropriate bias current is applied to the recording/playback heads R, P, and H. It's starting to flow. Also, when this switch S ₀ is switched to the contact b ₀ side, the output of the oscillator OSC is enhanced, and the bias current flowing to the recording/playback heads R, P, and H is enhanced until the recorded signal is erased. It's summery.

This switch S ₀ also corresponds to the switch S inserted between the amplifiers Am ₁ and Am ₂ , and when recording with the switch S ₀ switched to the contact a ₀ side, the contact of the switch S is Switch to side a and press the switch.
When _S0 is switched to contact _b0 , switch S is switched to contact b side. When the reverse point button 12 (see Fig. 1) is pressed, the switches S and _S0 are pushed together with a switch (not shown) that rotates the motor in the reverse direction, and the contacts are switched to contacts b and _b0 , respectively. It's getting old.

Also, when only the recording button 13 (see Figure 1) is pressed, switches S and S ₀ are connected to contacts a and a _0.
It's starting to change quickly. Also, a trap circuit formed by capacitor C and coil L
T ₀ prevents the bias current from affecting the amplifier Am ₂ during recording. Also, capacitor C ₀ is a coupling capacitor.

According to the present invention constructed in this way, when the recording button 13 is pressed during recording, the contacts of the switches S and _S0 are switched to a and _a0, respectively, and the output of the microphone M is switched to the amplifier A. ₁ and Am ₂ , it is applied to the recording/playback heads R, P, and H through which a bias current flows, and this is recorded on the magnetic sheet. After the spiral recording has been made in this manner, if you want to erase this recording, you can press the reverse button 12 over the recording button 13. When this is pushed in, the contact of switch S is switched from a to b, thereby shorting the output of amplifier Am ₁ , in other words, the output of microphone M, and at the same time, the contact of switch S ₀ is switched to b ₀ . Therefore, the bias current is increased until it erases the recorded signal. In this state, the motor rotates in reverse, so that the recording/playback heads R, P, and H function as erasing heads and return to the starting position by tracing the recorded track in reverse.
Therefore, the recording band is erased in this process.

In addition, in the above example, the changeover switch S is
Although it is inserted between Am ₁ and Am ₂ , it goes without saying that it may also be inserted between the amplifier Am ₂ and the trap circuit T ₀ as shown by the chain line.

Furthermore, in the above example, the recording/playback heads R, P,
The output of the oscillator OSC was increased and the erase current flowing through H was used for this purpose, but this was also done by connecting the DC power supply D and the switch _S1 , which replaced the selector switch _S0 , to the recording/playback heads R, P, and Of course, it is also possible to perform direct current cancellation by connecting between both terminals of H.

As described above, by reversing the moving direction of the magnetic head relative to the magnetic sheet during recording and erasing, and using the magnetic head as the erasing head, a completely recorded recording band can be erased.

Also, in the above example, when the record button and reverse button are pressed, the magnetic head changes from the recording/playback head to the erase head, and the motor rotates in reverse.
Of course, an erase button may be newly provided, and when pressed, an erase current flows through the magnetic head and the motor is reversed.

It is also generally known that in order to completely trace and demagnetize a magnetic recording band, the width of the erasing head is made wider than the width of the recording head. To satisfy this requirement, the magnetic head may be configured as shown in FIG. FIG. 4 is a plan view of the magnetic head device viewed from directly above, with the widths of the left and right cores being changed from the gap. That is, the core 40 is connected to the gap 40 as shown in FIG.
The core 40b on the left side is formed to be thin enough to correspond to the width of the recording/playback track, and the core 40c on the right side is formed thick so as to correspond to the width of the erase track. This can be housed in the head housing 41.

It is generally known that the track width of a magnetic track is approximately determined by the width of the core that slides in advance. Therefore, the magnetic head thus formed may be moved in the direction of arrow E during recording and reproduction, and in the direction of arrow D during erasing.

Alternatively, it may be configured as shown in FIGS. 6 and 7.
That is, the head housing 41 is formed of a short cylinder and is rotatably supported by a support shaft 42 passing through the center.Inside this cylindrical housing 41, there are wide erasing heads E and H and narrow recording and recording heads. It has built-in playback heads R, P, and H, respectively. The coils wound around the heads E, H and R, P, H are drawn out to contacts 43, 44, respectively. One of the contacts 43, 44 is always in contact with the sliding brushes 45, 46. That is,
When the recording/playback heads R, P, and H are in contact with the magnetic surface of the magnetic sheet 3, the contactor 43 contacts the sliding brush 45, supplies recording or playback current to the coil, and erases the head E/H. When the contactor 44 is in contact with the magnetic surface of the magnetic sheet 3, the contactor 44 contacts the sliding brush 46 and supplies an erasing current to the coil.

By configuring the magnetic head device as described above, when the magnetic head device moves in the direction of arrow D, the cylindrical housing 41 that is in contact with the magnetic surface of the magnetic sheet 3 moves counterclockwise around the support shaft 42. Since rotation is applied, this causes the erasing heads E and H to
is brought to a position where it contacts the magnetic surface, and the pin 47 fixed to the cylindrical housing 41 abuts against the stopper pin 49, so that the erasing heads E and H are opposed to the magnetic surface and the erasing current is supplied. demagnetization is performed. Next, when the magnetic head device moves in the direction of arrow E to perform recording or playback,
The cylindrical housing 41 that is in contact with the magnetic surface of the magnetic sheet 3 is rotated clockwise around the support shaft 42 due to friction, so that the recording/playback heads R, P, and H are brought into contact with the magnetic surface. When the pin 47 abuts against the stopper pin 48, the recording/playback heads R, P,
H is placed opposite the magnetic surface. A recording current is then supplied to perform the recording operation.

Even in this case, the head width can be made different during recording and playback and when erasing.

As mentioned above, the present invention is designed so that when the magnetic head device returns to the starting position after finishing recording,
This cleverly utilizes the ability to trace the same trajectory in reverse as when recording, and at this time an erasing current is applied to demagnetize unnecessary recordings, so a single magnetic head device can be used. recording, erasing,
It can perform three playback functions. Moreover, a degaussing function can be added very easily.

Note that even if you press the reverse button during playback, the recording circuit is not working, so the degaussing function will not work, and you will still be able to repeat as before.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of a spiral magnetic recording/reproducing device, Fig. 2 is a perspective view showing a mechanism in which a magnetic head device moves in a spiral shape, and Fig. 3 is a perspective view of the spiral magnetic recording/reproducing device of the present invention. A block diagram showing an example of an electric circuit during recording and erasing, FIG. 4 is a plan view showing an example of a magnetic head device, FIG. 5 is a perspective view showing the core in FIG. 4, and FIG. This figure is a sectional view showing another example of the magnetic head device, and FIG. 7 is a plan view of FIG. 6.

Claims (1)

[Claims for Utility Model Registration] A rotatable or swingable head housing that is supported in a direction facing the seat surface and moves in a spiral shape, and a head housing that is installed in the housing and whose head surface slides against the seat surface. a wide erasing head and a narrow recording/playback head, each of which has a coil wrapped around each head, and a contact which is fixed to the head housing; The erasing head and the sliding brush are placed in contact with each other, and the direction of the frictional force applied between the head in the head housing and the sheet surface changes in response to the direction of movement of the sheet surface. A spiral type magnetic recording and reproducing device characterized in that one of the recording and reproducing heads can be exposed to the sheet surface.