JPH0620232A - Magnetic head - Google Patents

Abstract

PURPOSE:To achieve that magnetic powder particles which have adhered to the front of a magnetic head are removed with high efficiency by installing an ultrasonic oscillator which gives ultrasonic vibrations to the magnetic head. CONSTITUTION:A magnetic head 32 is constituted of the following: a ring-shaped magnetic core 14 on which a coil has been wound and which is composed of Permalloy; a shielding plate 22 which is sandwiched by the core; and a shielding case 16 which has installed the magnetic core 14 and the shielding plate 22 at the inside. When the magnetic head 32 is not shaken to the front 18, an AC current is applied, for several seconds, to an ultrasonic oscillator 34 installed at the head 32, and ultrasonic vibrations are given to the head. The vibrations are transmitted to the main body of the magnetic head 32 and transmitted especially to the front 18 of the magnetic head 32. Thereby, magnetic powder particles which have adhered to the front 18 are shaken off. Consequently, the magnetic powder particles are not accumulated on the magnetic head 32, and the defect of a recording/replay operation to and from a magnetic tape, a drop in the quality of a sound and the like due to the adhersion of the magnetic powder particles are eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a magnetic head for recording, reading, or erasing information on a magnetic recording medium, and particularly to prevent magnetic particles of the magnetic recording medium from adhering to the front surface of the magnetic head sliding on the magnetic recording medium. .

[0002]

2. Description of the Related Art A magnetic recording device such as an audio tape deck or a car stereo is equipped with a magnetic head which is in sliding contact with the magnetic tape and records, reads, or erases information on the magnetic tape. FIG. 7 shows an example of a conventional magnetic head. Magnetic head 1
0 is a coil 12, an annular magnetic core 14 around which the coil 12 is wound, and a shield plate 22 sandwiched between the magnetic cores 14.
And a shield case 16 in which the magnetic core 14 and the shield plate 22 are arranged. A square opening is formed on the front surface 18 of the shield case 16 that slides on the magnetic tape 28, and the magnetic core 1 is opened through the opening.
4 and the tips of the shield plate 22 are exposed to the front surface 18. A magnetic gap 20 is formed in the exposed portion of the magnetic core 14. A tape guide 26 that guides a magnetic tape 28 is provided on the side wall of the shield case 16, and a terminal 24 connected to the coil 12 and a bracket 30 for mounting the magnetic recording device body on the rear surface side of the shield case 16. Is provided.

In such a magnetic head 10, a magnetic tape 28 slides on the front surface 18 thereof at a predetermined speed, and a magnetic field is applied to the magnetic tape 28 passing through the magnetic gap 20 for recording, or the magnetic tape is recorded. The magnetic field generated by the passage of 28 is taken out and read and reproduced.

[0004]

In the magnetic head of the type in which the magnetic tape 28 slides on the magnetic head 10 as described above, the magnetic tape 28 is the magnetic head 10.
When sliding on the front surface 18 of the magnetic tape 28, the magnetic tape 28 is worn and deteriorated, and the magnetic powder is separated from the magnetic tape 28.
There was a problem that it adhered to. In particular, when a magnetic head is mounted on a car stereo, the temperature inside the car tends to be high, and the humidity is high.
Since it is sometimes used under extremely strict conditions of up to 70%, magnetic powder easily adheres to the magnetic head. If the magnetic powder of the magnetic tape adheres to the front surface 18 of the magnetic head, recording / reproduction on the magnetic tape cannot be performed properly, resulting in a significant deterioration in sound quality. There is also a possibility that the magnetic tape may adhere to the front surface to cause inconvenience such as cutting of the magnetic tape.

The front surface 18 of the magnetic head 10 of such magnetic powder
Various proposals have been made in order to prevent the magnetic particles from adhering to the magnetic head. As a method for removing the magnetic powder adhering to the magnetic head, there is a method in which a cleaning mechanism is attached to the magnetic head. This is provided with a pad made of a roller-shaped or tape-shaped felt that comes into contact with the front surface 18 of the magnetic head. When the power is input to the magnetic recording device or when the magnetic tape is taken out, the pad serves as the magnetic head. By contacting the front surface 18 and vibrating or sliding the pad against the front surface 18,
The magnetic powder adhering to the front surface 18 is removed by rubbing. However, in this method, the magnetic powder is gradually deposited and accumulated on the pad itself by repeatedly operating the cleaning mechanism, and eventually the front surface 18 of the magnetic head is rubbed with the pad on which the magnetic powder remains attached, and the magnetic head Not only is the effect of removing magnetic powder from the magnetic recording medium not obtained, but the front surface 18 of the magnetic head is rather damaged. Also, the pad itself will wear out,
Its life span was limited. Therefore, it was necessary to replace the pad frequently, which was very inconvenient.

The present invention has been made to solve the above problems, and prevents magnetic particles of a magnetic recording medium from adhering to the front surface of a magnetic head, and can properly perform recording / reproduction on a magnetic recording medium. It is to provide a magnetic head.

[0007]

The magnetic head of the present invention comprises:
A magnetic head in which a magnetic recording medium slides on the front surface is provided with an ultrasonic transducer for applying ultrasonic vibration to the magnetic head.

[0008]

According to the present invention, the magnetic head is provided with the ultrasonic vibrator for transmitting the ultrasonic vibration, and the magnetic powder adhering to the front surface of the magnetic head is removed by the ultrasonic vibration. Since the magnetic particles are removed by vibration, no member is rubbed on the front surface, so the effect of removing the magnetic particles does not deteriorate, there is no need to replace the members, and there is no risk of damaging the magnetic head. Since ultrasonic vibration is used for the vibration, it does not affect the magnetic recording, and even when the magnetic recording medium is running,
Magnetic particles can be removed at all times by ultrasonic vibration. This vibration may be of any vibration mode such as longitudinal vibration, lateral vibration, flexural vibration, or a composite vibration of these vibrations.

[0009]

The present invention will be described below with reference to the drawings.
The same parts as those in the above-mentioned conventional example are designated by the same reference numerals and the description thereof will be omitted.

[Embodiment 1] A magnetic head 32 of Embodiment 1 shown in FIG. 1 is an annular magnetic core 14 made of permalloy around which a coil (not shown) is wound, and a shield plate sandwiched between the magnetic cores 14. 22 and a shield case 16 in which the magnetic core 14 and the shield plate 22 are arranged. The shield case 16 has a substantially rectangular parallelepiped box shape having wide side surfaces 40, 40 and narrow side surfaces 42, 42, and a front surface 18 on which a magnetic tape slides is gently curved so that a central portion thereof swells, and a rectangular opening 38 is formed. Are formed.

The tip ends of the magnetic core 14 and the shield plate 22 are exposed from the opening 38 to the front surface 18, and a magnetic gap 20 is formed in the exposed portion of the magnetic core 14. A terminal 24 connected to the coil is disposed on the rear surface side of the shield case 16.

Further, ultrasonic transducers 34 are provided on the narrow side surfaces 42, 42. The ultrasonic oscillator 34 is attached to the shield case 16 with an adhesive or the like. The number of ultrasonic transducers to be provided is not limited to two for one magnetic head, and may be only one or three or more. For the ultrasonic vibrator 34, a piezoelectric material such as PZT, an electrostrictive material, a magnetostrictive material, or the like can be used. A power supply device 36 is connected to the ultrasonic vibrator 34, and by applying an alternating current from the power supply device 36 to the ultrasonic vibrator 34, ultrasonic vibration is generated in the ultrasonic vibrator 34. The direction of the generated ultrasonic vibration is not limited, and the front surface 18 of the magnetic head is
On the other hand, they may be parallel, vertical, or neither of them.

In such a magnetic head 32, the magnetic tape slides on the front surface 18 thereof at a predetermined speed and a magnetic field is applied to the magnetic tape passing through the magnetic gap 20 for recording, or the magnetic tape passes. The magnetic field generated by is taken out and reproduced.

In the magnetic head 32 of this embodiment, when the magnetic tape is not sliding on the front surface 18 of the magnetic head, an alternating current is applied to the ultrasonic transducer 34 provided in the magnetic head 32 for several seconds, Ultrasonic vibration is generated in the ultrasonic vibrator 34. The ultrasonic vibration generated by the ultrasonic vibrator 34 is transmitted to the main body of the magnetic head 32, and particularly the front surface 18 of the magnetic head 32.
Be transmitted to. When the magnetic head 32 vibrates ultrasonically, the magnetic particles attached to the front surface 18 of the magnetic head are shaken off. Therefore, in the magnetic head of the present embodiment, since magnetic powder does not adhere to the magnetic head and does not accumulate, the recording / reproduction on the magnetic tape due to the adhesion of the magnetic powder is poor, the sound quality is deteriorated, and the magnetic property of the magnetic tape is reduced. It is possible to prevent the magnetic tape from being cut due to adhesion to the front surface 18 of the head. Further, since the magnetic powder is shaken off by vibration, the magnetic powder is not scraped off, and there is no risk of shortening the life due to wear of the mechanism for removing the magnetic powder, and maintenance-free can be achieved. In addition, the ultrasonic transducer 34
Is attached to the shield case 16 and an alternating current is applied to the ultrasonic transducer 34 to vibrate the magnetic head 32. The newly added component is the ultrasonic transducer 3
4 and the power supply device 36 that drives the ultrasonic transducer 34. Therefore, the magnetic head of this embodiment is very simple and can remove the magnetic powder without increasing the size of the magnetic recording apparatus.

By further attaching a cleaning mechanism to the magnetic head 32, the effect of removing magnetic particles can be enhanced. As shown in FIG. 2, the cleaning mechanism has a pad 44 to which a felt 46 is adhered, and when the magnetic tape is not slidingly running on the front surface 18 of the magnetic head 32, the pad 44 is attached to the magnetic head 32. Abut the front surface 18 of the. In the magnetic head of this embodiment, the ultrasonic transducer 34 vibrates the magnetic head 32 with the pad 44 in contact with the front surface 18. The ultrasonic vibration of the magnetic head 32 causes the front surface 18 to rub against the pad 44 abutting against the front surface 18, and the magnetic particles attached to the front surface 18 are removed. The cleaning mechanism of this embodiment is
Since the conventional pad does not vibrate or slide with respect to the magnetic head, but the magnetic head 32 vibrates with respect to the pad 44, it is not necessary to provide a drive device for vibrating or sliding the attached cleaning mechanism. Therefore, the manufacturing cost can be reduced and the magnetic recording device can be downsized.
Furthermore, because of ultrasonic vibration, the energy is very large compared to the conventional sliding, and unlike the conventional sliding of one to several times, it will reciprocate very many times in a short time, There is no leftover magnetic powder. Further, since the displacement of vibration is small, it is less likely to be scratched. The pad of the cleaning mechanism may be in the shape of a roller or a tape. If the pad is in the shape of a roller or a tape, the effect of removing magnetic particles by rotating the pad is improved and the pad is used every time it is used. By shifting the pad, dirt and wear of the pad can be reduced.

The magnetic powder may be removed by the ultrasonic vibrator 34 while the magnetic tape is running. The ultrasonic vibration generated by the ultrasonic vibrator 34 is about 40 kHz or higher, which does not cause any problem in magnetic recording, and preferably 100 kHz or higher. That is, since the audible band is 20 Hz to 20 kHz, this magnetic recording frequency is 100 kHz due to ultrasonic vibration.
This is because even if the above vibrations are applied, no practical inconvenience will occur. However, the amplitude due to ultrasonic vibration is preferably 0.1 μm or less. This is because if the amplitude is larger than 0.1 μm, the spacing loss between the magnetic head and the magnetic tape may be widened, which may affect the spacing loss.

Example 2 The ultrasonic transducer is not only provided on the narrow side surface 42 of the shield case 16 as shown in FIG. 1, but also as shown in FIG.
6 may be provided on the wide side surface 40. A magnetic head 48 in which the ultrasonic transducer 34 is provided on the wide side surface 40 of the shield case 16.
However, by applying an alternating current to the ultrasonic vibrator 34 to vibrate the ultrasonic vibrator 34 and generate ultrasonic vibrations in the magnetic head 48, the magnetic particles adhering to the front surface 18 can be removed. .

[Third Embodiment] The ultrasonic transducer may be provided not only on the side surface of the shield case but also on the front surface 18 as shown in FIG. However, it goes without saying that the magnetic tape 28 must be provided in a place where it does not hinder the running of the magnetic tape 28. In the case of the magnetic head 50 shown in FIG. 4, since the vibration can be directly transmitted to the front surface 18 of the magnetic head 50, the front surface 18 of the magnetic head can be effectively ultrasonically vibrated, and the adhesion of magnetic powder can be prevented. it can.

[Fourth Embodiment] Further, the ultrasonic transducer may be incorporated in the shield case 16 as shown in FIG. 5, instead of being provided on the outer surface of the shield case 16. That is, like the magnetic head 52, the ultrasonic transducer 34 is provided inside the shield case 16 in which the magnetic core 14 is disposed, and the ultrasonic transducer 34 vibrates the magnetic head 52 ultrasonically and attaches it to the front surface 18. You can remove the magnetic powder. In particular, since the ultrasonic transducer 34 is arranged inside the shield case 16, it is possible to reduce the possibility that the ultrasonic transducer 34 will be damaged when the magnetic head is attached to the magnetic recording device or the like. Yield is improved.

[Embodiment 5] The ultrasonic transducer may be incorporated inside the front surface of the magnetic head. That is, like the magnetic head 54 shown in FIG. 6, by providing the ultrasonic transducer 34 inside the front surface of the shield case 16, it is possible to effectively vibrate the front surface 18 by ultrasonic waves. Magnetic particles that adhere can be removed. In particular, since the ultrasonic transducer 34 is arranged inside the shield case 16, it is possible to reduce the possibility that the ultrasonic transducer 34 will be damaged when the magnetic head is attached to the magnetic recording device or the like. Not only the yield is improved, but the magnetic tape can be provided without hindering the running of the magnetic tape.

As is clear from the above description, the position where the ultrasonic vibrator is provided may be any position as long as ultrasonic vibration can be generated in the magnetic head.

Further, in the magnetic head of the present invention, in addition to the magnetic powder generated from the magnetic tape, various foreign substances attached to the front surface can be shaken off.

[0023]

According to the present invention, the magnetic powder adhered to the front surface of the magnetic head is removed by ultrasonically vibrating the magnetic head with the ultrasonic vibrator. The magnetic powder is removed very efficiently with a very simple method. It is possible. Since it removes magnetic particles by vibration, it does not rub any member on the front surface of the magnetic head, so the effect of removing magnetic particles does not decrease, there is no need to replace members, and there is a risk of damaging the magnetic head. Nor. Since the ultrasonic vibration is used for the vibration, the magnetic powder can be constantly removed by the ultrasonic vibration even when the magnetic recording medium is running, without affecting the magnetic recording. Therefore, since it is possible to prevent the magnetic particles from adhering to the front surface of the magnetic head, recording / reproducing is appropriately performed on the magnetic recording medium and the sound quality is not deteriorated. Also,
There is no problem such as adhesion of the magnetic recording medium to the front surface of the magnetic head or cutting of the magnetic recording medium due to adhesion of the magnetic powder.

[Brief description of drawings]

FIG. 1 shows a magnetic head of Example 1, and FIG.
1A is a plan view, FIG. 1B is a front view, and FIG. 1C is a side view.

FIG. 2 is a front view showing a case where a cleaning mechanism is attached to the magnetic head of the first embodiment.

FIG. 3 shows a magnetic head of Example 2, and FIG.
3A is a plan view, FIG. 3B is a front view, and FIG. 3C is a side view.

FIG. 4 shows a magnetic head of Example 3, and FIG.
4A is a plan view, FIG. 4B is a front view, and FIG. 4C is a side view.

FIG. 5 is a front view of a magnetic head according to a fourth embodiment.

FIG. 6 is a front view of a magnetic head according to a fifth embodiment.

FIG. 7 is a perspective view of a conventional magnetic head.

[Explanation of symbols]

 10 magnetic head 12 magnetic core 18 front face 22 shield plate 28 magnetic tape 32 magnetic head 34 ultrasonic transducer 48 magnetic head 50 magnetic head 52 magnetic head 54 magnetic head

Claims (1)

[Claims] 1. A magnetic head in which a magnetic recording medium slides on the front surface, wherein an ultrasonic transducer for applying ultrasonic vibration to the magnetic head is provided.