JPH03187008A - Floppy disk device - Google Patents

Abstract

PURPOSE:To reduce the quantity of crosstalk noise by setting the depth of the read/write gap of a magnetic head device to <=20mum. CONSTITUTION:Dimensions d2 of depth 1b of a read/write gap 1a is set to <=20mum. Since the magnetic resistance of a read/write core 1 is increased to reduce the magnetic flux leaked from an erase gap 2a to the read/write core 1 according as the gap depth 1b is reduced, the erase crosstalk is reduced by the reduction of this depth. The crosstalk is considerably reduced when the depth 1b of the read/write gap is <=20mum, and S/N is considerably improved to reduce the read error without providing a center core 3 with a nonmagnetic body layer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a floppy disk device, particularly to improving the reliability of a magnetic recording head mounted thereon.

[Prior Art] Fig. 9 is a perspective view showing the main parts of a conventional magnetic head for a floppy disk drive disclosed in, for example, Japanese Utility Model Application Publication No. 61-111016, etc., and Fig. 10 is a perspective view showing the main parts of the magnetic head for a conventional floppy disk device, as disclosed in, for example, Japanese Utility Model Application Publication No. 111016/1983. In Figure 1, which is a wiring diagram of a read/write coil and an erase coil, (1) is a read/write core, (2) is an erase core, and (3) is a read/write gap (1a) between these cores (1) and (2). ) and a center core forming an erase gap (2a).

(3a) is a non-magnetic layer provided in the center core (3), (4) is a back bar for opening a magnetic circuit, (4a)
is a non-magnetic layer provided in the back bar (4), (5)
is the read/write coil wound around the read/write core (1), (6) is the erase coil wound around the erase core (2), and (7) is the read/write coil connected to both ends of the read/write coil (5). Dump resistor (8) is an erase dump resistor connected to both ends of the erase coil (6), (9) is a read/write circuit, (10) is an erase circuit, (11) is a magnetic head floppy disk (not shown). It is a sliding surface with

In the above configuration, during signal recording, the sliding surface (11) slides on the floppy disk while the signal from the read/write circuit (9) is recorded on the floppy disk by the read/write dump (la). Erase gap (2a) precedes read/write gap (1a)
The previously recorded data is erased by the erase signal from the erase circuit (10). Similarly, during playback, the erase gap (2a) becomes the read/write gap (la
), while the sliding surface (11) slides on the floppy disk, the magnetization signal recorded on the floppy disk is detected by the read/write gap (la), and is electromagnetically generated by the read/write coil (5). It is converted and output as a reproduction voltage to the read/write circuit M(9). Further, a magnetization signal is also detected from the erase gap (2a), and magnetic flux is generated thereby in the erased core (2).

The erase coil (6) performs electromagnetic conversion and outputs a reproduction voltage, but it is not processed as a signal. At this time, the magnetic flux in the erase core (2) leaks to the read/write core (1), and this leaked magnetic flux causes the read/write coil (5) to
Although there is a possibility that an erase crosstalk voltage may be output from the magnetic layer, this leakage magnetic flux is blocked by the nonmagnetic layers (3a) and (4a), and the generation of erase crosstalk is reduced.

The erase dump resistor (8) installed between the erase coil (6) terminals is used to handle surges when the erase current is passed during signal recording, and its resistance value is equal to the DC resistance of the erase coil (6). The value is much larger than the value.

[Problems to be Solved by the Invention] Since the conventional magnetic head device is configured as described above, the erase crosstalk caused by the magnetic flux detected by the erase gap is reduced by the nonmagnetic layer provided in the center core. However, since the non-magnetic layer is provided in the center core, the regeneration efficiency of the read/write core deteriorates, and S
This caused the deterioration of the /N ratio. In addition, pseudo-gap noise occurs due to the non-magnetic layer itself, which ultimately results in a considerable deterioration of the S/N ratio.Furthermore, manufacturing of the center core is complicated, resulting in lower yields and higher costs. .

This invention was made to solve the above-mentioned problems, and provides an inexpensive floppy disk device equipped with a magnetic head device that reduces erase crosstalk and can maintain a high S/N ratio. The purpose is to

[Means for Solving the Problems] A floppy disk device according to the present invention is such that the depth of the read/write gap of the magnetic head device is 20 μm or less.

[Work] The floppy disk device in this invention is.

Since the depth of the read/write gap is made as small as 20 μm or less, the magnetic resistance of the read/write core is increased, and leakage of erase crosstalk magnetic flux to the read/write core is prevented.

[Embodiments of the invention] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the main parts of a magnetic head device according to an embodiment of the present invention. In the figure, (1) is a read/write core, (la) is a read/write gap, and (lb) is a read/write core.
is the depth of the read/write gap, (2) is the erase core, (2a) is the erase gap, (3) is the center core, (4) is the back bar, (4a) is the nonmagnetic layer,
(5) is the read/write coil, (6) is the erase coil, (11) is the sliding surface of the magnetic head, and the center core (3) is the sliding surface of the magnetic head.
) is similar to that shown in FIG. 9, except that the non-magnetic layer (3a) is not provided in the middle and the depth (tb) of the read/write gap is small.

Next, the operation will be explained. Since the write/read operations of this magnetic head device are the same as those of the conventional example, the explanation will be omitted, and only the erase crosstalk effect will be explained.

FIG. 2 is a configuration diagram of a magnetic head in which no non-magnetic layer is provided in the center core (3) and the read/write gap depth (1b) is set to the same dimension d1 as the conventional one.

Figure 3 shows the read/write gap depth (1
Fig. 4 is a configuration diagram of a magnetic head when the dimension d2 of (b) is reduced to 20 μm or less.
FIG. 5 is a configuration diagram of a magnetic head according to another embodiment of the present invention in which the dimension d2 of b) is reduced to 20 μm or less.
Reproduction signal voltage v between the read/write coil (5) terminals in the figure
1, FIG. 6 is a waveform diagram showing the reproduction signal voltage Vt between the read/write coil (5) terminals in FIG. 3, and FIG. 7 is a waveform diagram showing the reproduction signal voltage Vt between the read/write coil (5) terminals in FIG. 4. In the waveform diagram showing the signal voltage V3, (14) is the reproduced signal waveform detected by the read/write gap (1a), (15)
is the erase crosstalk waveform. FIG. 8 is a diagram showing the relationship between the depth (1b) of the read/write gap and the amount of erase crosstalk (db) in the embodiment of the invention shown in FIGS. 3 and 6. FIG. Here, assuming that the peak value of the reproduced signal waveform (14) is S, and the peak value of the erase crosstalk waveform (15) is N, 20Xlog(N
/S) is defined as the erase crosstalk amount.

As is clear from the figure, the depth of the read/write gap (
As 1b) is made smaller, the magnetic resistance of the read/write core (1) increases, and the magnetic flux leaking from the erase gap (2a) to the read/write core (1>) decreases, so that the erase crosstalk is reduced accordingly. When the write gap depth (tb) becomes 20 μm or less, the decrease is remarkable, and even without providing a nonmagnetic layer in the center core (3), the S/N ratio is significantly improved and read errors are reduced.

In addition, as shown in FIG. 4, if the depth (lb) of the read/write gap is reduced to 20 μm or less in the structure in which the nonmagnetic layer (3a) is provided in the center core (3), the seventh
As shown in the figure, the amount of crosstalk can be further reduced.

[Effects of the Invention] As described above, according to the present invention, since the depth of the read/write gap of the magnetic head device is set to 20 μm or less, the amount of crosstalk noise can be significantly reduced even without a nonmagnetic layer in the center core. This has the effect of reducing the amount of noise, simplifying the configuration of the magnetic head device, and providing an inexpensive floppy disk device.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the main parts of a magnetic head device according to an embodiment of the present invention, FIG. 2 is a configuration diagram of a conventional magnetic head in which a non-magnetic layer is not provided in the center core, and FIG. FIG. 4 is a configuration diagram of a magnetic head according to another embodiment of the invention, FIG. 5 is a reproduction voltage waveform diagram of the magnetic head according to the configuration of FIG. 2, and FIG. The figure is a reproduction voltage waveform diagram of the magnetic head with the configuration shown in Figure 3, Figure 7 is a reproduction voltage waveform diagram of the magnetic head with the configuration shown in Figure 4, and Figure 8 is the depth dimension of the read/write gap and the amount of erase crosstalk. FIG. 9 is a perspective view showing the main parts of a conventional magnetic head for a floppy disk device.
Figure 0 is a wiring diagram of the read/write coil and erase coil during signal reproduction. In the figure, (1) is the read/write core, (la) is the read/write gap, (lb) is the depth of the read/write gap, (2) is the erase core, (2a) is the erase gap, (3) is the center core, (5) is a read/write coil, and (6) is an erase coil. The same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] Equipped with a magnetic head device that includes a read/write core around which a read/write coil is wound, an erase core around which an erase coil is wound, and a center core that forms a read/write gap and an erase gap between these two cores. A floppy disk device, characterized in that the read/write gap has a depth of 20 μm or less.