JPS61264507A - Magnetic head - Google Patents

Abstract

PURPOSE:To prevent a failure in side erasing with respect to all radiuses by providing a recording and reproducing head chip in tae fixed end and providing a side erasing head chip in a moving piece end. CONSTITUTION:The recording and reproducing head chip is provided in the fixed end of a head base 20 whose one end is the fixed end and the other is the moving end, and the side erasing head chip is provided in the moving end. They are finished to the same spherical surface initially, and the side erasing head chip is displaced to a desired position thereafter. Thus, side erasing of recording and reproducing tracks is performed surely to prevent a failure in erasing even if tracks on a disc-shaped recording medium are different in radius, and a wider track width is attained for the same track density and S/N of signals is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic head used in a magnetic recording/reproducing device, and more particularly to a magnetic head for recording and reproducing digital signals on a disk-shaped medium.

2. Description of the Related Art In recent years, advances in magnetic recording have been remarkable, especially in devices that record and reproduce data information on disk-shaped media, such as so-called hard disks, which are made of aluminum disks coated with magnetic material, and so-called floppy disks, which are made of PET coated with magnetic material. Advances in disc technology are remarkable, and progress is being made towards higher recording densities. These technologies are known, for example, in the special issue of the magazine Interface 1ssaMAY regarding floppy disk drives.In order to further increase the density, writing a larger number of recording tracks on a smaller disk is being considered. When track density is increased, a problem arises in terms of compatibility or weather resistance, and whether the magnetic head is accurately positioned over the recorded track during reproduction. Normally, the tracking accuracy cannot be set to "0", so immediately after recording, the sides of the recording track width are slightly erased (site race) to make the recording pattern width and the playback track width different. Even if the data is not tracked accurately or if data is overwritten on previously written data, measures are taken to ensure that there are no unerased marks.

As a secondary magnetic head, those shown in FIGS. 8 and 9 are employed. 1 and 3 are read/write gaps for recording and reproducing data, and 2°4 is a site erase gap for erasing the sides of the recorded recording pattern. The type shown in FIG. 8 performs side erasing using a seven ringing magnetic field in the site erase gap, and the type shown in FIG. 9 performs side erasing on several dimensions.

Problems to be Solved by the Invention The conventional site erase method does not have any problems when the recording gap and erasing gap distances are sufficiently short compared to the circumferential diameter. When the outer diameter becomes smaller and the track width also becomes narrower, as shown in FIG.
The gap spacing 6 creates a site erase width 4 and an unerased width 6. Even if the erasing head gap is moved to the inner circumferential side with the type of head shown in Figure 9 taking into account the gap interval 6, it is impossible to follow all the tracks because the circumference differs depending on the position of each track. It is possible. For this reason, it was necessary to increase the site race width and narrow the residual track width.The present invention eliminates the above-mentioned conventional drawbacks, and provides a magnetic head that can completely perform side erasing and is easy to manufacture. The purpose is to provide the following.

Means for Solving the Problems In order to solve the above problems, the magnetic head of the present invention includes:
A head base with a fixed end on one end and a movable end on the other is provided with a head chip for recording and reproducing at the fixed end and a head chip for side erasing at the movable end, and is finished to an approximately uniform spherical surface at the initial stage, and then moved to the desired position. The present invention has a structure in which the side erasing head chip is displaced according to the above structure.Even if the circumferential radius of the track is different in a disc-shaped recording medium, the side erasing of the recording/reproducing track can be performed. Therefore, with the same track density, a wider track width can be obtained, and the signal-to-noise ratio is improved.

Furthermore, the machining accuracy of the head is not required to be as high as in the case of an integrated type.

Embodiment To explain the present invention using an embodiment, the sendust block A11. shown in FIG. The gap surface of B12 was polished flat, and as shown in FIG. 3, the pack gap portion was heat-treated at 760Q using a thin silver solder 14 via a gap spacer 13 to form a gap. Thereafter, as shown in FIG. 4, the core chip 16 was produced by slicing it into desired track widths 16. As shown in FIG. 6, the core chip 16 for recording/reproducing has a track width of 60 μm, the gap spacer has a thickness of 0.4 μm, and the side erasing core chip 19 has a track width of 30 μm.
The gap spacer was 6 μm. Further, the fixed frame 18 that holds these core chips 16 has a concave shape with a winding window 17 for which winding wire is opened. Next, as shown in FIG. 6, a dividing groove 22 is provided to form a head base 20 having a fixed end and a movable end. This requires piezoelectric ceramics 2 on the head adhesive surface of one movable end.
1 is attached. Then, as shown in FIG. 7, a core block for site erasing is bonded to the surface on which the piezoelectric ceramic 21 is attached, and a core block for recording/reproducing is bonded to the other fixed end.

Pb-Zr-Ti ceramics were used as the piezoelectric ceramics 21, and electrodes 23 were provided in the thickness direction. Thereafter, as shown in FIG. 1, the front surface of the head is polished circularly and the winding window 17 is polished.
A read/write winding 24 and a site erase winding 25 are applied to each of the heads to complete the head. Piezoelectric ceramics 21
In this case, a change in the bimorph power supply 26 causes a displacement in the direction shown by the arrow 27. As a final finishing touch to the head, the front surface was finished with abrasive tape, and the chip was also rounded in the width direction, and the front surface of the head was machined into a nearly spherical surface so that the head touch would not change even when displaced by bimorph.

By attaching the head shown in FIG. 1 to a floppy disk drive device, interlocking with the track signal, and changing the bimorph power supply 26 to change the site erase position on each circumference, all track radial positions can be adjusted. There was no unerasable residue at all. Therefore, the unerased track width due to the recording/reproducing gap and the side erase gap interval can be ignored, and the track width can be made wider by that amount.

Further, as a second embodiment, a head that was mechanically displaced by a via and fixed as it was without using the bimorph power source 26 was used in an apparatus having a relatively large circumferential radius. In this case, even when the head was made by integrating the recording/playback track and the side erase track, the head processing accuracy was rough and good. In other words, the processing accuracy of the head requires high accuracy only in the gap distance of the side erase head, and the rest can be finely adjusted using screws.

Effects of the Invention As described above, according to the present invention, by providing a recording/reproducing head chip at the fixed end and a side erasing head chip at the movable end, unerased traces of side erasing can be eliminated at all circumferential radii. Even if the machining accuracy of the head is relatively rough, a satisfactory side-erasing magnetic head can be constructed without causing any problems.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the magnetic head of the present invention;
Figures 2 to 7 are perspective views showing the manufacturing process of the head shown in the embodiment of the present invention, Figures 8 and 9 are head configuration diagrams for explaining the conventional head, and Figure 10 is the current disadvantage. FIG. Name of agent: Patent attorney Toshio Nakao and 1 other M1
Figure 2 t'7 t't Figure 6 Figure 8 Figure 9 Figure 10

Claims (2)

[Claims] (1) A magnetic head in which a head base has a fixed end and a movable end, a recording/reproducing head chip is provided at the fixed end, and a head chip for side erasing the side surface of a recording/reproducing track is provided at the movable end. (2) The magnetic head according to claim 1, wherein the side erase head chip is configured to be moved by a piezoelectric bimorph.