JPS6029913A - Magnetic head - Google Patents

Abstract

PURPOSE:To avoid the excess erasion of a recording track and to prevent deterioration of the reproduction output voltage by forming a gap between an inside erasion core and a recording/reproducing core by means of a partition plate. CONSTITUTION:A nonmagnetic spacer 14 (partition plate) 14 made of a metal, ceramic, glass, etc. is provided between an erasion core 2 and a recording/reproducing core 1 with the length covering the entire core 2. As a result, the excess erasion done in the inner circumferential direction of a magnetic disk can be avoided when the erasion is performed by erasion heads 2 and 3 after the recording is through with the recording/reproducing head 1. In this case, the thickness of the spacer 14 is varied to cope with the variation of the diameter of the magnetic disk. Furthermore it is not always needed for the length of the spacer 14 to cover entirely both cores 3 and 1 but enough to move back and erasion gap 7 toward the inner circumference side by a prescribed width.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a magnetic head, more particularly a recording/reproducing core for recording and reproducing information in sliding contact with a rotating disc-shaped magnetic recording medium, and The present invention relates to a magnetic head that includes an erasing core that is disposed on both sides of the recording/reproducing core and erases information recorded on a recording medium.

Prior Art Conventionally, this type of magnetic head has been used in magnetic disk devices such as floppy disks, and is used to record, reproduce, and erase information by slidingly contacting a rotating disc-shaped magnetic recording medium. It is configured. In this case, in the magnetic head, as shown in FIG. 1, erasing cores 2.3 are arranged to sandwich a recording/reproducing core from both sides. A recording/reproducing coil 4 is wound around the recording/reproducing core 1, and an erasing coil 5 is wound around the erasing cores 2 and 3.

Further, the recording/reproducing core 1 has a rear core 9, and an erasing core 2.
．． 3 has rear cores 1o and these rear cores 9.10
A magnetic circuit is formed in each core. In these magnetic circuits, a gap 6 is formed on the side of the recording/reproducing core, and a gap 7.8 is formed on the side of the erasing core. A DC current is supplied to the erasing coil 5 to generate a DC magnetic field in the erasing cores 2 and 3, and the information formed on the magnetic recording medium is erased by the DC erasing magnetic field generated from the gap 7.8.

When recording and reproducing signals on a magnetic disk using a magnetic head configured in this way, the magnetic disk (partial view of the magnetic disk DC) shown in FIG.
is rotated in the direction by a driving means (not shown). In this case, record II on the axis 11 of the radius passing through the center point 12.
(2) A magnetic reproducing gap 6 formed in the raw core 1 is arranged. Furthermore, the erasing gap 7.8 is arranged at a predetermined distance from the recording/reproducing gap 6 in the 1'-row. With the magnetic head arranged in this way, after a signal is recorded via the recording/reproducing cap 6, the information is erased in the erasing gaps 7.8 arranged on both sides thereof.

However, when recording on a magnetic disk with such a magnetic head, the erase head 2 in the inner circumferential direction of the magnetic disk
The data width recorded by the recording/playback gap is 6.
At the same time that the portion 13b in the figure a is erased, the portion 13a left unerased by the erasing head 3 disposed in the outer circumferential direction. In reality, extra erasing is performed due to the ringing phenomenon of the erasing core, so no unerased data is left behind.However, as mentioned above, if extra data and tracks are erased, the higher the density of the data, the more the data will be erased. Since the width of the generating core becomes narrower, the reproduced output voltage becomes lower and the reliability deteriorates, which is a big problem.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a magnetic head which eliminates the conventional drawbacks such as "duplicity", prevents redundant erasing by the erasing head, and enables reliable magnetic recording and reproducing.

Example The present invention will be described in detail below according to embodiments shown in the drawings.

FIG. 3 shows an embodiment according to the present invention.
Parts that are the same as those in the figures are designated by the same reference numerals, and their explanation will be omitted.

In this embodiment as well, the erasing cores 2.3 are arranged to sandwich the recording/reproducing core 1 from both sides, but between the erasing core 2 and the recording/reproducing core 1 there is a non-magnetic material made of metal, ceramic, glass, etc. Recording and reproducing core with spacer 14!
, a structure in which the erase core 2 is interposed with a length extending over the entire erase core 2 is adopted.

By arranging the spacer plates in this way, record 111 raw head 1
When data is recorded by the erase head 2.3 and then erased by the erase head 2.3, unnecessary erasure that occurs in the inner circumferential direction of the magnetic disk can be prevented.

In this case, by changing the thickness of the spacer plate, it is possible to cope with changes in the diameter of the magnetic disk. Further, the length of the spacer plate 14 does not necessarily have to extend over the entire erasing core 3 and recording/reproducing core 1, but may be such that it retreats the erasing gap 7 by a predetermined width toward the inner circumferential side.

Another embodiment is shown in FIG. 4, and in this embodiment as well, the same parts as in FIGS. 1 to 3 are given the same reference numerals, and the explanation thereof will be omitted. .

In this embodiment, a spacer plate 15 made of metal, glass, ceramic, etc. is arranged between the erasing cores 2.3, and a similar effect can be achieved by arranging the recording/reproducing core 1 in alignment with the side surface of the erasing core 2 on one side. It is effective.

Effects As explained above, according to the present invention, in a magnetic head in which erasing cores are placed from both sides at a position sandwiching a recording/reproducing core from both sides, a gap is provided between the inner erasing core and the recording/reproducing core by means of a spacing plate. As a result, it is possible to prevent unnecessary erasing of recording tracks, and to prevent a decrease in reproduction output voltage, thereby providing a magnetic head with improved reliability.

[Brief explanation of drawings]

FIG. 1 is a perspective view illustrating the structure of a conventional magnetic head, FIG. 2 is an explanatory diagram illustrating problems of the conventional magnetic head, and FIGS. 3 and 4 each show a magnetic head according to the present invention. FIG. 3 is a perspective view and a plan view illustrating different embodiments. ...Recording/reproducing core 2.3...Erasing core 4.5...
・Coil 6...Recording/reproducing gap 7.8...Erasing gap 14, 15...° spacing plate 1 Fig. 3 Fig. 4 3

Claims (1)

[Claims] A recording and reproducing core that records and generates information by slidingly contacting a disc-shaped magnetic recording medium, and an erasing core that is placed on both sides of this recording IIf raw core and erases information recorded on the recording medium. 1. A magnetic head comprising: a spacer plate interposed between a side surface of a recording/reproducing core and an erasing core disposed on the inner circumferential side.