JPS6023765Y2 - Magnetic reproducing head using Hall element - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a magnetic reproducing head using a Hall element.

A so-called "Hall head" using a thin film Hall element made of semiconductor InSb or the like as a reproducing head has appeared.

This device utilizes the Hall effect, a phenomenon in which electrons in a solid react to magnetism and generate a voltage, and has the following characteristics.

(1) Since the output is proportional to the residual magnetism on the magnetic tape (magnetic flux response type), the output does not change depending on the frequency unlike when using a coil, and for example, the output is large even at extremely low frequencies. is obtained.

(2) Since the output impedance is purely resistive and has no inductance component, the waveform is not distorted even in response to sharply changing signals, and exhibits extremely good transient response characteristics.

In the magnetic reproducing head using the above Hall element, the Hall element is used in the output detection section of the rear chip of the magnetic head, and is interposed in the rear gap of the magnetic circuit of the magnetic head. .

Also, in order to obtain a thick output from the above Hall element,
A yoke core for concentrating the magnetic flux passing through the rear chip of the magnetic circuit is joined to the Hall element.

Therefore, due to the structure of the magnetic circuit, the front chip in which the front gap (reproduction gap) is formed, the magnetic substrate in which the Hall element is formed, and the yoke core for magnetic flux concentration each have different shapes and magnetic permeabilities, and the magnetic The elements constituting the circuit are non-uniform.

For this reason, if a head structure that emphasizes playback sensitivity and is compatible with processing technology (for example, a structure in which a Hall element is interposed in the center of the magnetic circuit) is used, the directivity with respect to external guidance will be significantly reduced. It will deteriorate.

In addition, the playback head with the above structure has a structure in which a coil is wound around the rear chip to pick up the signal, as compared to a conventional head in which a coil is wound around the rear chip to pick up the signal. There is a lot of noise.
There was a drawback that N was poor.

The present invention eliminates the above-mentioned drawbacks of the conventional magnetic reproducing head using a Hall element. , this point will be referred to as the magnetic neutral point), thereby improving the directivity for external guidance, thereby providing a magnetic reproducing head using a Hall element with low sound distortion and a good S/N ratio. The purpose is to

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In the figure, reference numeral 1 denotes a front chip, in which a front gap (reproduction gap) 2 is formed.

Reference numeral 3 denotes a magnetic substrate on which a Hall element 4 interposed in the rear gap is formed, and is made of ferrite or the like.

Note that the Hall element 4 formed on the magnetic substrate 3 made of ferrite or the like is made of InSb (indium-
Antimony) etc. are used.

Reference numeral 5 denotes a yoke core whose portion connected to the Hall element 4 is formed into a steeple shape in order to concentrate the magnetic flux passing through the magnetic circuit onto the Hall element 4.

Note that 6 indicates the average magnetic path in the magnetic circuit constituted by the above-mentioned front chip 1, magnetic substrate 3, and yoke core 5, and the 0 point is the center of the magnetic path length.

Further, the 0 point is a magnetic neutral point which is the center when considering the magnetic path 6 in terms of magnetic resistance, and the Hall element 4 is interposed at this position.

The 0 point and the 0 point each indicate a quarter point when the magnetic path 6 is considered in terms of magnetic resistance.

In the magnetic head with the above structure, the directivity with respect to external induction is +90° at point ■, 00 at point 0 where the Hall element is located, and 0 at -20° at point 0, which is the center of the magnetic path.
A point indicates -90°.

In addition, the present proponent's device in which the Hall element 4 is interposed at the position of the magnetic neutral point ■, which is the center when considering the magnetic path 6 in terms of head resistance, has a higher directivity than the conventional coil type head. It has been confirmed that the fit of the coil type is 0°±20°, whereas that of the present invention described above is 0°±10′.

As described above, according to the present invention, in a magnetic reproducing head in which a Hall element is interposed in the rear gap, the Hall element is interposed at the magnetic neutral point, which is the center when considering the magnetic path of the magnetic circuit in terms of magnetic resistance. Because it has a structure that allows
The directivity for external guidance at the position where the Hall element is interposed can be set to 00, and the sound distortion is small.
/N It is possible to provide a magnetic reproducing head using a good Hall element.

[Brief explanation of drawings]

The figure shows the construction of an embodiment of a magnetic reproducing head using a Hall element according to the present invention. DESCRIPTION OF SYMBOLS 1...Front chip, 2...Front gap, 3...Magnetic substrate, 4...Hall element, 5...Curved yoke core, 6...magnetic path, ■...magnetic neutral point, ◎...center of magnetic path.

Claims (1)

[Scope of utility model registration request] A magnetic reproducing head in which a Hall element is interposed in a rear gap has a structure in which the Hall element is interposed at a magnetic neutral point of a magnetic circuit constituted by a front chip and a rear chip in which a front gap is formed. A magnetic reproducing head using a characteristic Hall element.