JPS6136282B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a magnetic recording/reproducing apparatus, and more particularly, to an improvement in a magnetic recording/reproducing apparatus employing a cassette, generally called an audio cassette or a compact cassette, in which a magnetic tape is previously stored in a half.

First, the structure of an audio cassette (hereinafter simply referred to as cassette) will be explained based on FIG. In the figure, 1 is a half, and inside this half 1 are two reel hubs 2, 2, a magnetic tape 3 whose both ends are fixed to the reel hubs 2, 2, guides 4, 4 of this magnetic tape 3, and a magnetic tape 3. A felt pad 5, etc. against which is pressed is provided. Further, positioning holes 6, 6 and capstan insertion holes 7, 7 are provided in the side portion of the half 1, and magnetic head insertion holes 8, and pinch roller insertion holes 9, 9 are provided in the front portion, respectively.

Figure 2 shows a plan view of a conventional magnetic recording/reproducing device.
Figure 3 shows a side view. In both figures, 10 is a base, and two reels 1 are mounted on this base 10.
1 and 11 are arranged. Each reel 11, 11
When the cassette 12 having the above structure is fed in the direction of the arrow 13 in FIG. 3, the reel hub 2,
2 so as to be rotatably driven. Also, during this fitting, the two positioning pins 14, 14 protruding from the base 10 are inserted into the positioning holes 6, 6 of the half 1, and the half 1 is positioned, and one of the capstans The capstan 15 is inserted into the insertion hole 7.

When the above operation is performed, the half 1 is fixed onto the base body 10 by a fixing mechanism (not shown). Then, the support arm 17 of the pinch roller 16 disposed on the base body 10 rotates, and the pinch roller 16 is inserted into the pinch roller insertion hole 9 on one side of the half 1, so that the magnetic tape 3 is pinched. It is sandwiched between the roller 16 and the capstan 15. At the same time, the head plate 19 provided with the magnetic head 18 is regulated by the guide pins 20, 20 and moves in the direction of the arrow 21, so that the magnetic head 18 is moved in the direction of the arrow 21.
8 is inserted into the magnetic head insertion hole 8 of the half 1, the magnetic tape 3 is sandwiched between the magnetic head 18 and the felt pad 5 in the half 1. Further, the capstan 15 is driven to rotate at a constant speed, the magnetic tape 3 runs in the direction of the arrow 34, and is wound from one reel hub 2 to the other reel hub 2, thereby performing recording and reproduction. When fast forwarding or rewinding the magnetic tape 3, the pinch roller 16 and the magnetic head 18 are moved back and away from the magnetic tape 3. In addition, in FIG. 3, 22 is a reel stand, and 23 is a flywheel.

In the conventional device described above, since the magnetic head 18 is movably provided on the base body 10 by the head plate 19, a mechanical gap exists between the head plate 19, the base body 10, and the guide pin 20. For this reason, the magnetic head 18 has a unique resonance frequency, and when it is externally vibrated, such as when used in a vehicle, the resonance of the magnetic head 18 has the disadvantage that recording and reproduction sound and sound quality are significantly impaired.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic recording/reproducing apparatus which can eliminate the above-mentioned drawbacks, prevent vibration of a magnetic head, and increase the recording frequency bandwidth.

Embodiments of the present invention will be described below based on the drawings.

In FIGS. 4 and 5, 24 is a sub-plate placed under the base 10, and is set to be movable in the direction of arrow 25. The sub-plate 24 includes two reel motors (only one is shown) 27 that rotate the reels 11, 11, and two positioning pins 1.
4 and 14 are provided. Reel 11, 11
The positioning pins 14 and 14 protrude above the base body 10.

The cassette 12 is of conventional construction. When the reels 11, 11 are fitted and locked to the reel hubs 2, 2 of the cassette 12, and the positioning pins 14, 14 are fitted into the holes 6, 6 on the side surface of the half 1, the half 1 is positioned. , the half 1 is driven by a certain amount in the direction of the arrow 25a together with the sub-plate 24, and the magnetic head 18 is placed in the hole 9 on one side of the front side of the half 1, and the erasing head 2 is placed in the hole 9 on the other side.
9 are inserted, and both heads 18 and 29 come into contact with the magnetic tape 3, and the hole 8 in the center of the front
A roller 30 is inserted into the half 1, and a magnetic tape 3 is inserted between the roller 30 and the felt pad 5 in the half 1.
is caught.

The roller 30 rotates as the magnetic tape 3 runs, and the roller 30 rotates when the magnetic tape 3 runs.
By pressing with an appropriate force, the frictional force necessary for rotation is obtained. When the roller 30 rotates, the rotation detector 31 is activated and a signal corresponding to the running speed of the magnetic tape 3 is transmitted. The rotation detector 31 includes a tachometer that detects the rotation speed of the roller 30 as a voltage, a rotary encoder that extracts the rotation speed as a pulse signal, and the like. Since the load torque of the rotation detector 31 is sufficiently small, the slip rate between the magnetic tape 3 and the roller 30 can be said to be less than the normally allowed 0.1%, and there is no practical problem.

The speed signal from the rotation detector 31 is sent to the comparator 3.
2, the magnetic tape 3 is compared with the reference signal from the reference signal generator 33, and based on this comparison, a control signal for the reel motor 27 is obtained, and the magnetic tape 3 runs at a constant speed in the direction of the arrow 34, thereby performing recording and reproduction. In addition,
35 is a driving power source for the reel motor 27.

The erasing head 29 is fixed to the base 10 and is configured to erase recorded signals on the magnetic tape 3 when necessary.

Details of the magnetic head 18 are shown in FIGS. 6 and 7. In both figures, numeral 36 is a head core provided with a coil 37, and this head core 36 is fixed to the base 10 in order to prevent its vibration and maintain good recorded and reproduced sound and sound quality. head core 3
6, a gap 39 is formed in the magnetic flux generating portion 38 inserted into the hole 9 of the half 1. 40
An auxiliary magnetic pole shares a magnetic circuit with the head core 36, and is vertically movably supported at the end of a bypass core 42 which has a coil 41 and is integrally formed with the head core 36. Both coils 3 above
7 and 41 are connected in series.

As already mentioned, when the half 1 is driven in the direction of the arrow 25a in FIG. 4, the magnetic head 18 comes into contact with the magnetic tape 3 through the gap 39. Thereafter, the auxiliary magnetic pole 40 in the lowered state in FIG.
As shown in the figure, the magnetic tape 3 is inserted into the hole 7 in the side surface of the half 1, and the magnetic tape 3 is sandwiched between the auxiliary magnetic pole 40 and the gap 39. The air gap magnetic field generated by the gap 39 is transmitted to the head core 36.
This overlaps with the magnetic field in the tape thickness direction generated between the magnetic field and the auxiliary magnetic pole 40 to induce a so-called cross-field effect that suppresses the spread of the air gap magnetic field distribution, thereby increasing the recording frequency bandwidth.

When removing the cassette 12 from the base 10, the auxiliary magnetic pole 40 is pulled out from the hole 7 of the half 1, and then the half 1 is driven in the direction of the arrow 25b in FIG. 5, in the reverse order of the above operation.

8 and 9 show other examples of the magnetic head 18. In both figures, reference numeral 43 denotes a contoured core having a coil 44, and on the side opposite to the magnetic flux generating section 38 that contacts the magnetic tape 3, has a field core 45 supporting an auxiliary magnetic pole 40 so as to be movable up and down. In this case, the auxiliary magnetic pole 40 is also driven upward from the lowered state shown in FIG. 8 as shown in FIG. It can be done. With this configuration, the air gap magnetic field obtained by the magnetic flux generating section 38 generates a sharp air gap magnetic field distribution with the auxiliary magnetic pole 40, and it is also possible to perform so-called perpendicular magnetization recording in which magnetization is recorded in the thickness direction of the magnetic tape 3. I can do it,
The recording frequency band can be increased.

Although the auxiliary magnetic pole 40 is illustrated as having a circular cross section, it may have another shape, for example, a square shape, if necessary.

As described above, according to the present invention, there is provided a magnetic recording and reproducing apparatus that can prevent vibration of the magnetic head, maintain good recorded and reproduced sound and sound quality, and increase the recording frequency bandwidth.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an audio cassette, FIG. 2 is a plan view of a conventional magnetic recording/reproducing device, FIG. 3 is a side view of FIG. 2, and FIG. 4 is a magnetic recording/reproducing device according to an embodiment of the present invention. 5 is a side view of FIG. 4, FIGS. 6 and 7 are perspective views of the magnetic head, and FIGS. 8 and 9 are perspective views showing other examples of the magnetic head. . 3... Magnetic tape, 7, 9... Hole, 12... Audio cassette, 18... Magnetic head, 36... Head core, 38... Magnetic flux generating section, 40... Auxiliary magnetic pole, 42...
Bypass core, 43...Contour head core, 45
...Field core. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. The core of the magnetic head is fixed to a base body on which the audio cassette is mounted, with its magnetic flux generating part inserted into a hole formed in the front part of the audio cassette, and it shares a magnetic circuit with the core. and an auxiliary magnetic pole that is removably inserted into a hole formed in a side surface of the audio cassette and that sandwiches the magnetic tape in the audio cassette with the magnetic flux generating section is supported by the core. magnetic recording and reproducing device.