JPH09102101A - Magnetic recording and reproducing device and magnetic head device applied therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic recording/reproducing device and a magnetic head device realizing narrow gap by obtaining reproducing output characteristic complied with a reproducing head of narrow gap and divising the gap structure of the reproducing head. SOLUTION: This device is HDD provided with a reproducing head having plural gaps Ga, Gb of different gap lengths and located in the same track and the respective outputs of reproducing signals have prescribed time differences when data are reproduced from the track of a disk 1. This device is also provided with a signal processing circuit 10 for synthesizing reproducing signals for every gap Ga, Gb and generating a reproducing signal corresponding to a gap length narrower than the respective gap lengths, concretely the difference of the respective gap lengths.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing device such as a hard disk device, and more particularly to a magnetic reproducing technique using a multi-gap as a magnetic head during a data reproducing operation.

[0002]

2. Description of the Related Art Conventionally, a magnetic recording / reproducing apparatus such as a hard disk drive (HDD) magnetically records data on a disk, which is a recording medium, by using a magnetic head (hereinafter simply referred to as a head), and records data from the disk. To play.

The head generates a recording magnetic field through the gap during the data recording operation, and detects the recording magnetization from the disk during the data reproducing operation and converts it into a reproduction signal. In recent years, in HDDs, there are a method in which one head (usually, an inductive type thin film head) also performs a data recording / reproducing operation and a recording / reproducing separated type method. The recording / playback separation type system uses an MR (Magnetoresis) as a playback head.
Tive) head and an inductive thin film head as a recording head.

By the way, particularly in HDDs, in order to reduce the size and increase the storage capacity, a high data recording density is required. In order to realize this, there are two directions of increasing the recording track density and increasing the linear recording density of each track.

In order to increase the linear recording density of the track, it is necessary to improve the reproducing resolution of the head. In order to improve the reproduction resolution, a technique for reducing the spacing between the reproducing head (recording / combining head or MR head) and the disk (flying amount of the head) and a technique for reducing the gap length of the reproducing head are required. It The former technique is a slider (a member that holds the head).
Very low levitation technology and contact traveling technology are being studied.
On the other hand, with regard to the latter, it is necessary to devise a manufacturing technique for the head, but an effective technique for realizing a narrow gap for narrowing the gap length has not been developed.

In particular, in the MR head, which is attracting attention as being most suitable for high recording density, it is necessary to secure a certain distance or more between the MR film and the shield in order to maintain insulation between the MR film and the shield film. There is a limit to narrowing the gap.

On the other hand, in order to increase the recording track density, it is necessary to narrow the track of the reproducing head in order to avoid crosstalk with adjacent tracks. However, in the current head structure in which the MR film is arranged in the track width direction and the reproduction width is defined by the distance between the electrodes on both sides of the MR film, there is a limit to narrowing the track.

[0008]

In order to increase the linear recording density in an HDD or the like, it is necessary to improve the reproducing resolution of the head. Therefore, the gap length of the reproducing head is narrowed. Effective means need to be developed. When the gap length is large, the reproduction output is reduced due to the gap loss, so narrowing the gap is an important technique for increasing the recording density. However, as described above, it is difficult to simply narrow the gap of the head because of the manufacturing technique and the characteristics of the MR head.

Further, in order to increase the recording track density, it is necessary to narrow the reproducing track width of the head. Therefore, it is necessary to develop an effective means for narrowing the reproducing track width. However, as described above, it is difficult to simply narrow the gap of the head because of the manufacturing technology and the structure of the MR head.

A first object of the present invention is to obtain a reproducing output characteristic corresponding to a reproducing head having a narrow gap by devising a gap structure of the reproducing head, and as a result, to realize a magnetic gap with a narrow gap. It is to provide a recording / reproducing device and a magnetic head device.

A second object of the present invention is to obtain a reproducing track width corresponding to a reproducing head with a narrow track by devising the structure by making the reproducing head multi-gap and performing signal processing, and consequently narrowing the track. Another object is to provide a magnetic recording / reproducing device and a magnetic head device that realize the above.

[0012]

According to a first aspect of the present invention, when data is reproduced from a track of a recording medium, it has a plurality of gaps located on the same track and having different gap lengths.
The magnetic recording / reproducing apparatus is provided with a reproducing head configured so that respective reproduction signal outputs have a predetermined time difference. Further, the device of the present invention synthesizes the reproduced signals output for each gap to generate a reproduced signal corresponding to a gap length narrower than each gap length, specifically, a narrow gap length corresponding to the difference between the gap lengths. It is provided with signal processing means for generating.

With such a structure, the reproduction signal corresponding to the narrowed gap can be obtained as a result by devising the gap structure by the multi-gap and the signal processing without narrowing the gap itself of the reproducing head. You can

As a concrete configuration of the signal processing means of the present invention, from the passage of the leading edge of the gap at the position preceding the certain recording position on the track to the passage of the leading edge of the gap at the rear position. When the time of is set to T, there is a delay unit that delays the reproduction signal corresponding to the gap at the preceding position by the time T.
Further, it has difference combining means for outputting a reproduction signal corresponding to a difference between the output of the delay means and the reproduction signal output corresponding to the gap at the rear position. Further, the signal processing means has processing means such as level adjustment and polarity inversion of the reproduction signal corresponding to each gap. Further, the present invention assumes an MR head having a structure in which a magnetoresistive element is included in each of the gaps as a reproducing head. In this MR head, the trailing edge side of the gap at the leading position and the leading edge side of the gap at the rear position can be configured by the common magnetic shield member.

According to a second aspect of the present invention, when data is reproduced from a track of a recording medium, it is arranged along the track direction and has a plurality of gap portions having different reproduction track widths (or different reproduction off-track patterns). The magnetic recording / reproducing apparatus is provided with a reproducing head configured so that respective reproduction outputs have a predetermined time difference. Further, according to the present invention, the reproduction signals output for each gap portion are combined, and the reproduction track width narrower than the reproduction track width of each gap portion, specifically, the reproduction track width of each gap portion (one gap portion is In the case of having a plurality of reproduction tracks, there is provided a means for generating a reproduction signal corresponding to a narrow reproduction track width corresponding to the difference of the sum of the reproduction track widths).

With such a structure, it is possible to narrow the reproducing track as a result by devising the head structure by making the multi-gap and by performing signal processing, rather than simply narrowing the track of the reproducing head.

As a concrete configuration of the signal processing means of the present invention, the time from the passage of the gap at the position preceding the certain recording position on the track to the passage of the gap at the rear position is defined as T. In this case, it has a delay means for delaying the reproduction signal corresponding to the gap at the preceding position by the time T. Further, it has difference combining means for outputting a reproduction signal corresponding to a difference between the output of the delay means and the reproduction signal output corresponding to the gap at the rear position. In addition, the signal processing means,
It has a processing means such as polarity inversion of the reproduction signal corresponding to each gap. Further, also in the present invention, an MR head having a structure in which a magnetoresistive element is included in each of the gaps is assumed as the reproducing head. Further, the multi-gap head can be configured by a magnetic shield member shared by the trailing edge side of the leading position and the trailing edge side of the trailing position.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows H related to the first embodiment.
FIG. 2 is a block diagram showing a main part of the DD, and FIG. 2 is a conceptual diagram for explaining the operation of the head structure and the signal processing circuit related to the present embodiment. (Structure of First Embodiment) This embodiment assumes an HDD using a thin film ring head for both recording and reproduction.
During the data reproducing operation, the action of the two first gaps and the second gap is utilized to consequently generate a reproduced signal corresponding to the reproduced signal of one reproducing head with a narrow gap.

As shown in FIG. 1, the HDD of this embodiment has a disk 1 as a recording medium, a head 2, a signal processing circuit 10, and a read channel 8. The read channel 8 is a data reproduction circuit that reproduces data from a reproduction signal output from the head 2 (output of the signal processing circuit 10 in this embodiment), and may be either a peak detection method or a PRML method. (Structure of Head 2) The head 2 of the present embodiment is a thin film ring head for both recording and reproduction, and has two different gap lengths.
It has two gaps Ga and Gb.

Here, a relatively wide gap length (eg 0.30 μm) is the first gap Ga, and a narrow gap length (eg 0.25 μm) is the second gap Gb. In other words, the head 2 of this embodiment is
The thin film head having the first gap Ga and the thin film head having the second gap Gb are connected to the magnetic shield member 2a.
It is a head having a structure that is coupled (or integrated) via.

As shown in FIG. 2, the positional relationship between the first and second gaps Ga and Gb is such that the first gap Ga precedes the direction of rotation of the disc on the track TR formed on the disc 1. It is located in the position Further, the second gap Gb is arranged at a position that is delayed with respect to the first gap Ga in terms of time.

As a specific example, the rear L of the trailing edge 2c forming the first gap Ga (for example, 2.5 μ)
The trailing edge 2d of the second gap Gb is located at the position m). This is because when the peripheral speed in the rotational movement of the disk 1 is, for example, (5 m / s), a certain point of the track TR passes the trailing edge 2c of the first gap Ga and then the second gap G.
This is a positional relationship in which a time difference of a required time T (for example, 0.5 μs) until the trailing edge 2d of b is passed is generated.

The opposite edges forming the first and second gaps Ga and Gb are the leading edges 2b,
2e. The required time Ta until the leading edge 2e passes with reference to the position of the leading edge 2b is the difference (La> L) between the gap length La of the first gap Ga and the gap length Lb of the second gap Gb.
It becomes longer by the amount of b) (Ta> T). (Structure of Signal Processing Circuit 10) The signal processing circuit 10 is shown in FIG.
As shown in FIG. 3, head amplifiers 3 and 4 provided for each of the gaps Ga and Gb of the head 2, a delay circuit 5, a level adjusting amplifier 6, and an adding circuit 7 are provided.

The head amplifiers 3 and 4 are provided with respective gaps Ga,
The reproduced signal converted according to the recording magnetization detected by Gb is amplified. The delay circuit 5 has a first
Is a circuit for performing a process of delaying the reproduction signal RA1 corresponding to the gap Ga of 1 by the required time T.

The level adjustment amplifier 6 is an amplification means or a width reduction means for adjusting the level of the reproduction signal RA1 delayed by the delay circuit 5 to a predetermined value. If the difference between the reproduction signal RA1 and the reproduction signal RB1 is calculated without adjusting the output level, only the component corresponding to the difference in gap length is not extracted, and the signal waveform with the left-right symmetry collapsed. Become. That is, in order to properly extract the signal of the portion corresponding to the difference between the gap Ga and the gap Gb, it is necessary to adjust the relative output levels of the reproduction signal RA1 and the reproduction signal RB1, and therefore the level adjustment is performed. Amplifier 6
Is provided. Therefore, conversely, a width reducing means for adjusting the level of the reproduction signal RB may be provided.

In this embodiment, the delay processing of the delay circuit 5 and the level adjustment processing of the level adjustment amplifier 6 are called normalization processing. That is, the delay circuit 5 and the level adjusting amplifier 6 are
This is a circuit for normalizing the signal for combining the reproduction signal RA1 and the reproduction signal RB by the adding circuit 7.

The adder circuit 7 sets the reproduction signal RA2 corresponding to the first gap Ga normalized by the delay circuit 5 and the level adjusting amplifier 6 as the positive input side, and reproduces the reproduction signal RA2 corresponding to the second gap Gb. Combine RB as the inverting input. That is, the adder circuit 7 has the first and second gaps G
A reproduction signal RC corresponding to the gap length difference (La-Lb) between a and Gb is generated and output to the read channel 8. (Operation of the First Embodiment) The operation of the head 2 and the signal processing circuit 10 of the present embodiment will be described below with reference to the solitary wave reproduction signal waveforms of FIGS.

First, as shown in FIG. 2, it is assumed that the head 2 is positioned on the designated track TR of the disk 1 and the data reproducing operation is started. The reproduction signal RA1 corresponding to the first gap Ga of the head 2 is amplified by the head amplifier 3 and output as a signal waveform as shown in FIG. Here, the vertical line in FIG. 3A indicates the time when the trailing edge of the gap Ga passes over the central portion of the magnetic transition region on the recording medium.

On the other hand, the reproduction signal RB corresponding to the second gap Gb is amplified by the head amplifier 4,
As shown in (B), the reproduction signal RA1 is output with a delay of time T. Here, the vertical line in FIG.
It shows the time when the trailing edge of the gap Gb passes over the central portion of the magnetic transition region on the recording medium.

The reproduced signal RA1 is added as a normalized signal waveform RA2 as shown in FIG. 4A by the delay processing by the delay circuit 5 for the time T and the level adjusting processing by the level adjusting amplifier 6. It is output as the positive input of the circuit 7.

On the other hand, the reproduction signal RB corresponding to the second gap Gb of the head 2 is amplified by the head amplifier 4 and output as a signal waveform as shown in FIG. 3 (B). The reproduction signal RB is input to the adding circuit 7 as an inverted signal waveform as shown in FIG.

The adder circuit 7 receives the input signal waveform RA2
And the inverted waveform of the signal waveform RB are combined, and a signal waveform corresponding to the output difference between the reproduction signal RA2 and the reproduction signal RB is output as shown in FIG.

That is, the adder circuit 7 consequently detects that the gap Ga. The difference between the gap lengths La and Lb of Gb (L
This means that the reproduced signal waveform (see FIG. 5B) corresponding to the gap length of (a−Lb = 0.05 μm) is generated and output.

As described above, according to this embodiment, the signal processing circuit 10 for performing the normalizing process, the polarity reversing process and the synthesizing process on the reproduced signals corresponding to the respective gaps Ga and Gb of the head 2 causes the respective gaps Ga to be changed. , Gb, a reproduction signal corresponding to the gap length difference is generated. Therefore, as a result, the narrow gap length (La-Lb = 0.0
It is possible to obtain a signal equivalent to the reproduction signal from the head having a gap of 5 μm). As a result, the same effect as narrowing the gap of the head can be obtained as a result, without requiring a special manufacturing technique.

As the delay time in the delay circuit 5, the required time Ta until the leading edge 2e passes with reference to the position of the leading edge 2b is used instead of the required time T with respect to the trailing edge. May be used for. (Second Embodiment) The second embodiment relates to a recording / reproducing separated type head using an MR head as a reproducing head. The recording / reproducing separated type head normally has a composite head structure in which an inductive type thin film head used as a recording head in an HDD and an MR head are combined.

Furthermore, the MR head of the second embodiment is
As shown in FIG. 6A, it has magnetoresistive elements 20 a and 20 b for forming two gaps, magnetic shield members 21 a to 21 c, and a coil (magnetic field generating coil for recording) 22.

The magnetic shield member 21b serves both as a shield forming a trailing edge on the magnetic resistance element 20a side and a shield forming a leading edge on the magnetic resistance element 20b side. In this way, by sharing the shield member between the trailing edge of the front gap and the leading edge of the rear gap, the structure is simpler than the case where separate shield members are used, and the distance between the gaps is increased. Can be shortened.

The magnetoresistive elements 20a and 20b each have a film thickness of about 0.05 μm. Further, as shown in FIG. 6B, the gap W1 between the leading edge side of the magnetic shield member 21a and the magnetoresistive element 20a, and the leading edge side of the magnetic shield member 21b and the magnetoresistive element 2.
The distance W3 from 0b is about 0.25 μm. Furthermore, the distance W2 between the trailing edge side of the magnetic shield member 21b and the magnetoresistive element 20a is about 0.20 μm. On the other hand, the distance W4 between the trailing edge side of the magnetic shield member 21c and the magnetoresistive element 20b.
Is wider than the interval W2 and is about 0.22 μm. Also,
The common magnetic shield member 21b has a thickness of about 1.00 μm.

In the MR head having such a structure, the magnetic shield members 21a, 21 including the magnetoresistive element 20a.
The distance b corresponds to the first gap Ga in the above-described first embodiment. Similarly, the distance between the magnetic shield members 21b and 21c including the magnetoresistive element 20b corresponds to the above-mentioned second gap Gb.

That is, in the data reproducing operation, the first gap Ga preceding the disk 1 detects the recording magnetic field and is converted into a reproducing signal via the magnetoresistive element 20a. Further, the second gap Gb at the position delayed in time detects the recording magnetic field and is converted into a reproduction signal via the magnetoresistive element 20b.

Here, the distance L from the leading edge side of the magnetic shield member 21a forming the first gap Ga to the leading edge side of the magnetic shield member 21b forming the second gap Gb is about 1.50 μm. Is.

In the above data reproducing operation, when the peripheral speed (rotation direction X) of the disk 1 is, for example, 6 m / s, after a certain point of the track passes the trailing edge of the first gap Ga, The time T required to pass the trailing edge 2d of the gap Gb of 2 is 0.2, for example.
It is about 5 μs. That is, the first gap Ga and the second gap Gb have a positional relationship such that the reproduction output has a time difference corresponding to the time T.

Also in the MR head having such a structure,
With the signal processing circuit 10 of the first embodiment described above, the first
Difference between the gap length of the gap Ga and the gap length of the second gap Gb (resultantly W4-W2 = 0.02μ).
It is possible to obtain a reproduction signal waveform from the MR head having a gap length corresponding to m).

Specifically, the reproduction signal corresponding to the first gap Ga is amplified by the head amplifier 3 and then delayed by the delay circuit 5 for the time T. Further, level adjustment processing is performed by the level adjustment amplifier 6, and here, the reproduced signal corresponding to the first gap Ga is inverted in polarity and input to the addition circuit 7.

On the other hand, the reproduction signal corresponding to the second gap Gb is amplified by the head amplifier 4 and then input to the adding circuit 7 as it is. The adder circuit 7 uses the first gap Ga that has been subjected to the normalization process including the inversion process.
And the reproduction signal corresponding to the second gap Gb are combined, and as a result, the narrow gap length (0.
A reproduction signal corresponding to the reproduction signal waveform from the MR head having a gap of 02 μm) is generated.

The second embodiment has been described for the case where the gap structure of the MR head is set to the specifications shown in FIG. 6B, but the present invention is not limited to this. That is, in the gaps Ga and Gb, the magnetoresistive elements 20a and 20b are provided.
Various specifications in which the position of is changed are conceivable. For example, the specification is such that the magnetoresistive element 20a is arranged substantially at the center of the gap between the magnetic shield members 21a and 21b. (Third Embodiment) FIG. 7 is a block diagram relating to a third embodiment corresponding to an application form of the above-described first embodiment. That is, in the third embodiment, in the signal processing circuit 10, the head amplifiers 3 and 4 are provided with different predetermined amplification factors so that the head amplifiers 3 and 4 also have the function of level adjustment and the level adjustment. Adjustment amplifier 6
Is omitted. (Fourth Embodiment) FIG. 8 shows H related to the fourth embodiment.
FIG. 11 is a block diagram showing a main part of a DD, and FIG. 9 is a schematic diagram showing a structure of a head tip portion related to the present embodiment,
FIG. 10 corresponds to the positional relationship on the recording medium of each reproduction gap portion in the head relating to the present embodiment, the area on the recording medium reproduced by each gap portion, and the output finally obtained by signal processing. FIG. 6 is an explanatory diagram illustrating a region on a recording medium that is to be used.

(Structure of Fourth Embodiment)
Assuming an HDD using a thin film ring head for both recording and reproduction, the effect of the first gap portion and the second gap portion is used during the data reproduction operation, and as a result, one narrow track reproduction is performed. A signal corresponding to the reproduction signal of the head is generated.

As shown in FIG. 8, the HDD of this embodiment has a disk 1 as a recording medium, a head 32, a signal processing circuit 100, and a read channel 8. The read channel 8 is a data reproduction circuit that reproduces data from a reproduction signal (output of the signal processing circuit 100 in this embodiment) output from the head 32, and may be a peak detection method or a PRML method.

(Structure of Head 2) Head 3 of this embodiment
Reference numeral 2 denotes a thin film ring head for both recording and reproduction, and as shown in FIG. 9, it has two gap portions Gd and Ge having the same gap length and different track widths. Here, a relatively wide track width Wd (for example, 2.0 μm) is defined as the first gap portion Gd, and a narrow track width We (for example, 1.5 μm) is defined as the second gap portion Ge. In other words, the head 2 according to the present embodiment has the first gap portion G
The thin film head having d and the thin film head having the second gap portion Ge are coupled (or integrated) via the magnetic shield member 32a.

The first and second gaps Gd and Ge are arranged in parallel so that the gap ends on the same side pass over the same position on the disk 1. That is, the areas on the disc 1 reproduced by the first gap Gd and the second gap Ge are areas A and B shown in FIG. 10, respectively.
Corresponds to the part.

As a specific example, the second gap Ge is provided at a position L (eg, 2.5 μm) behind the first gap Gd.
Are arranged to be located. This is required from when a certain point of the track TR passes through the first gap Gd to when it passes through the second gap Ge when the peripheral velocity in the rotational movement of the disk 1 is (5 m / s), for example. Time T
This is an arrangement relationship in which a time difference of only (for example, 0.5 μs) occurs. Here, since the gap lengths of the two gaps Gd and Ge are equal, the distance between the two gaps may be measured with any of the leading edge of the gap, the trailing edge, or the middle of both edges as a reference. In FIG. 9, the gap distance L is displayed based on the trailing edge.

(Structure of Signal Processing Circuit 100) As shown in FIG. 8, the signal processing circuit 100 includes head amplifiers 3 and 4 provided for each gap Gd and Ge of the head 32, a delay circuit 5, and an addition circuit. Circuit 7.

The head amplifiers 3 and 4 are connected to the gaps Gd,
The reproduction signals RD1 and RE1 converted according to the recording magnetization detected by Gb are amplified. The delay circuit 5 uses the reproduction signal RD corresponding to the first gap Gd which precedes in time.
2 is a circuit for performing a process of delaying 2 by the required time T.

The adder circuit 7 synthesizes the reproduction signal RD3 corresponding to the first gap Gd delayed by the delay circuit 5 as a positive input side and the reproduction signal RE2 corresponding to the second gap Ge as an inverting input side. To do. That is, the adder circuit 7
Is a reproduction signal RF corresponding to a region C included in the region A of FIG. 10 reproduced by the first gap Gd and not included in the region B reproduced by the second gap Ge.
Is generated and output to the read channel 8.

(Operation of the Fourth Embodiment) As described above, according to the present embodiment, the gaps Gd and Ge of the head 32 are formed.
The difference between the track width Wd of the first gap Gd and the track width We of the second gap Ge of the head 32 (( Wd-We =
This means that reproduction signals corresponding to a reproduction track width of 0.5 μm) are combined and output.

Therefore, as a result, a signal equivalent to the reproduction signal from the head having a narrow track width gap can be obtained. As a result, the same effect as narrowing the track of the head can be obtained as a result, without requiring a special manufacturing technique. (Fifth Embodiment) The fifth embodiment relates to a recording / reproducing separated type head using an MR head as a reproducing head. The recording / reproducing separated type head normally has a composite head structure in which an inductive type thin film head used as a recording head in an HDD and an MR head are combined.

FIG. 11 shows an HDD related to the fifth embodiment.
12 is a block diagram showing the main part of FIG. 12, FIG. 12 is a schematic diagram showing the structure of the head tip portion related to this embodiment, and FIG. 13 is a recording of each magnetoresistive element in the head related to this embodiment. FIG. 6 is an explanatory diagram illustrating a positional relationship on a medium, a region on the recording medium reproduced by each magnetoresistive element, and a region on the recording medium corresponding to an output finally obtained by signal processing.

(Structure of Head 42) The head 42 of this embodiment is a recording / reproducing separated type MR head.
As shown in (A), the magnetic shield members 42a, 42b
Gap portion sandwiched between the magnetic shield member 42 and
It has two gap parts called a gap part Gh sandwiched between c and 42d. The magnetoresistive element 20 is provided in the gap portion Gg.
g1 and 20g2, the gap portion Gh has a magnetoresistive element 20h, and the two gap portions Gg and Gh have the same gap length.

The magnetoresistive elements 20g1 and 20g2 are arranged on the same line and electrically connected in series. Also,
The magnetoresistive elements 20g1, 20g2, and 20h have the same thickness, and as shown in FIG. 12B, the magnetoresistive elements and the corresponding leading edges are arranged at equal intervals d1 and d3. . As a result, the distances d2 and d4 between the magnetoresistive element and the trailing edges corresponding thereto are also equal.

Here, a relatively narrow reproduction track width W
g1 (eg 1.0 μm), Wg2 (eg 1.0 μm
The gap portion having the magnetoresistive elements 20g1 and 20g2 of m) is referred to as a first gap portion Gg, and the gap portion having the magnetoresistive element 20h having a wide reproduction track width Wh (for example, 2.2 μm) is referred to as a second gap portion Gh. To do. In other words, the head 42 of the present embodiment has the first gap portion Gg.
It is a head having a structure in which the MR reproducing head having the above and the MR reproducing head having the second gap portion Gh are combined (or integrated). Here, the reproduction track widths Wg1 and Wg2
May or may not be equal, but at least Wg1
It is necessary to satisfy + Wg2 <Wh.

The first and second gap portions Gg and Gh are arranged in parallel so that the ends of the magnetoresistive element on the same side pass over the same position on the disk 1. That is, the magnetoresistive elements 20g1 and 20g2 of the first gap portion Gg.
The area on the disc 1 to be reproduced by means of the section 1 corresponds to the areas D1 and D2 shown in FIG. The area of the second gap portion Gh on the disk 1 reproduced by the magnetoresistive element 20h corresponds to the area E shown in FIG.

As a specific example, the second gap portion Gh is arranged at a position 2.5 μm behind the first gap portion Gg. This is because when the peripheral speed in the rotational movement of the disk 1 is, for example, (5 m / s), the track T
After a certain point of R passes through the first gap Gg,
The arrangement relationship is such that a time difference of a required time T (for example, 0.5 μs) before passing through the gap Gh is generated.
Here, since the gap lengths of the two gaps Gg and Gh are equal to each other, the distance between the two gaps may be measured with any of the leading edge of the gap, the trailing edge, or the middle of both edges as a reference. In FIG. 12, the gap distance L is displayed with reference to the leading edge.

(Structure of Signal Processing Circuit 30) As shown in FIG. 11, the signal processing circuit 30 includes head amplifiers 3 and 4 provided for each of the gap portions Gg and Gh of the head 42, a delay circuit 5, and a delay circuit 5. And an adder circuit 17. That is, the signal processing circuit 30 replaces the input signal RD1 with the signal RG1 from the gap portion Gg and the input signal RE1 with the signal RH1 from the gap portion Gh in the signal processing circuit 100 of the fourth embodiment shown in FIG. The input signal of the adder circuit 7 is the same as that of the positive and negative signals.

Output R from the gap portion Gg of the head 42
G1 is a magnetoresistive element 20g arranged in the gap portion Gg.
The output is 1,20 g2. Magnetoresistive element 20g
1, 20g2 are electrically connected in series, and an output RG1 obtained therefrom is a magnetoresistive element 20g1, 20g.
This corresponds to the sum of the two outputs, that is, the sum of the areas D1 and D2 on the medium in FIG. In addition, the gap portion Gh of the head 42
Is an output from the magnetoresistive element 20h arranged in the gap portion Gh, and corresponds to the area E on the disk 1 in FIG.

The head amplifiers 3 and 4 have respective gaps Gg and G.
The reproduction signals RG1 and RH1 converted according to the recording magnetization detected by h are amplified. The delay circuit 5 uses the reproduction signal RG2 corresponding to the first gap Gg that precedes in time.
Is a circuit for delaying the required time T by the time. The adder circuit 17 uses the reproduction signal RG3 corresponding to the first gap Gg delayed by the delay circuit 5 as an inverting input side, and reproduces the reproduction signal RH corresponding to the second gap Gh.
2 is combined as the positive input side.

That is, the adder circuit 17 has the first gap G
The first part included in the area E of FIG.
Region D1, which is reproduced by the gap Gg of FIG.
A reproduction signal RI corresponding to the area F not included in D2 is generated and output to the read channel 8.

(Operation of the Fifth Embodiment) As described above, according to the present embodiment, the gaps Gg and Gh of the head 42 are adjusted.
The signal processing circuit 30 that performs the delay process, the polarity inversion process, and the synthesizing process on each reproduction signal corresponding to the magnetoresistive element 20h included in the second gap Gh of the head 42.
Reproduction track width Wh and the reproduction track width Wg of the magnetoresistive elements 20g1 and 20g2 having the first gap Gg.
1, the difference between Wg2 and the sum (Wg1 + Wg2) {Wh- (W
This means that a reproduction signal corresponding to the reproduction track width of g1 + Wg2) (= 0.2 μm)} is generated and output.

Therefore, as a result, a signal equivalent to the reproduction signal from the head having a narrow track width gap can be obtained. As a result, the same effect as narrowing the track of the head can be obtained as a result, without requiring a special manufacturing technique. (Sixth Embodiment) The sixth embodiment relates to a recording / reproducing separated type head using an MR head as a reproducing head. The recording / reproducing separated type head normally has a composite head structure in which an inductive type thin film head used as a recording head in an HDD and an MR head are combined.

FIG. 14 shows an HDD related to the sixth embodiment.
FIG. 3 is a block diagram showing a main part of FIG. Signal processing circuit 100
Is basically the same as the signal processing circuit 100 of the fourth embodiment, and the input signal RD of the fourth embodiment shown in FIG.
1 to the signal RJ1 from the gap part Gj and the input signal RE
No. 1 is replaced with the signal RK1 from the gap portion Gk.

FIG. 15 is a schematic diagram showing the structure of the head tip portion relating to the sixth embodiment, and FIG. 16 is the position of each magnetoresistive element in the head relating to this embodiment on the recording medium. FIG. 3 is an explanatory diagram illustrating a relationship and a region on the recording medium reproduced by each magnetoresistive element and a region on the recording medium corresponding to an output finally obtained by signal processing. (Structure of Head 52) The head 52 of the present embodiment is a recording / reproducing separated type MR head, and as shown in FIG.
It has two gap parts, a gap part Gj sandwiched between the magnetic shield members 52a and 52b and a gap part Gk sandwiched between the magnetic shield members 52b and 52c. The gap portion Gj has a magnetoresistive element 20j, and the gap portion Gj
k has a magnetoresistive element 20k and two gap portions G
The gap lengths of j and Gk are equal. As shown in FIG. 15A, the magnetoresistive elements 20j and 20k have the same thickness and the same length in the track direction, and the magnetoresistive element 20k has no magnetoresistive effect in the central portion of the MR film of the magnetoresistive element 20j. The conductive portion 20l is provided. In addition, as shown in FIG. 15B, the distances d1 and d3 between each magnetoresistive element and each corresponding leading edge are arranged to be equal. As a result, the distances d2 and d4 between the magnetoresistive element and the trailing edges corresponding thereto are also equal.

Here, the gap portion having the magnetoresistive element 20j having the reproducing track width Wj (for example, 2.1 μm) without the non-MR conductor portion in the MR film portion is set as the first gap portion Gj, and is set in the middle of the MR film portion. The gap portion having the magnetoresistive element 20k having the non-MR conductor portion is referred to as the second gap portion Gk.
And The reproducing track width Wk of the magnetoresistive element 20k is equal to the reproducing track width Wj of the magnetoresistive element 20j, but has a non-reproducing track portion in the reproducing track. The width of the non-reproduction track portion is set to Wl (for example, 0.1 μm).

Further, in this embodiment, the first gap portion G
The trailing edge of j and the leading edge of the second gap portion Gk share the shield member. By thus sharing the shield member 52b with the trailing edge of the front gap and the leading edge of the rear gap, the structure is simpler than the case where separate shield members are used, and the distance between both gaps is reduced. can do.

The first and second gap portions Gj and Gk are arranged in parallel, and the ends of the magnetoresistive elements pass above the same position on the disk 1. That is, the area on the disk 1 reproduced by the magnetoresistive element 20j in the first gap portion Gj corresponds to the area G shown in FIG. In addition, the magnetoresistive element 20 of the second gap portion Gk
The area on the disc 1 reproduced by k corresponds to the area H shown in FIG.

As a specific example, the second gap portion Gk is arranged at a position 1.5 μm behind the first gap portion Gj. This is because when the peripheral speed in the rotational movement of the disk 1 is (6 m / s), the track T
After a certain point of R passes through the first gap Gj,
Is a positional relationship in which a time difference of a required time T (for example, 0.25 μs) to pass through the gap Gk is generated. Here, since the gap lengths of the two gaps Gj and Gk are equal to each other, the distance between the two gaps may be measured with any of the leading edge, the trailing edge, or the middle of both edges of the gap as a reference. In FIG. 15, the gap distance L is displayed with reference to the middle of both edges.

(Operation of the Sixth Embodiment) The output RJ from the gap portion Gj of the head 52 is the output from the magnetoresistive head 20j arranged in the gap portion Gj, and is output to the area G on the disk 1 shown in FIG. It corresponds. The output Rk from the gap portion Gk of the head 52 is the gap portion Gk.
is an output from the magnetoresistive element 20k arranged at k,
This corresponds to the area H on the disk 1 shown in FIG.

The signal processing circuit 100 operates similarly to the case of generating the signal RF from the input signals RD1 and RE1 in the fourth embodiment. Therefore, the first gap Gj
The read signal RL corresponding to the region I included in the region G shown in FIG. 16 reproduced by the second gap Gk and not included in the region H shown in FIG. Output to.

As described above, according to the present embodiment, the signal processing circuit 100 for performing the delay process, the polarity inversion process, and the synthesizing process on the reproduced signals corresponding to the gaps Gj and Gk of the head 52 has the first gap. The second gap G included in the region G shown in FIG. 16 reproduced by Gj.
A reproduction signal RL corresponding to a region I not included in the region H shown in FIG. 16 reproduced by k is generated and output to the read channel 8. This is because the width Wl (= 0. 0) of the non-reproduction area in the reproduction track of the second gap Gk of the head 52.
That is, a reproduction signal corresponding to a reproduction track width of 1 μm) is generated and output.

Therefore, as a result, it is possible to obtain a signal equivalent to the reproduced signal s from the head having a narrow track width gap. As a result, the same effect as narrowing the track of the head can be obtained as a result, without requiring a special manufacturing technique.

[0079]

As described in detail above, according to the present invention, firstly, by devising the gap structure of the reproducing head and the signal processing means, the reproducing head having a narrow gap is eventually obtained without requiring a special manufacturing technique. It is possible to obtain a reproduction output characteristic corresponding to Further, even when an MR head is used as the reproducing head, a narrow gap is eventually achieved in a state in which the characteristics of the MR head are met without particularly reducing the thickness of the MR film or the distance between the MR film and the shield. be able to.
Therefore, since the reproducing resolution of the head can be improved by narrowing the gap length of the reproducing head, the linear recording density can be particularly increased. When the present invention is applied to a disk recording / reproducing apparatus such as a small HDD, it is possible to realize a disk recording / reproducing apparatus having a large storage capacity as the linear recording density is increased.

Secondly, by devising the structure of the reproducing head and the signal processing means, it is possible to obtain a reproducing output characteristic corresponding to a head having a narrow reproducing track width without requiring a special manufacturing technique. Further, even when the MR head is used as the reproducing head, it is possible to realize a narrower track as a result without particularly narrowing the interval between the electrodes on both sides of the MR film. Therefore, by narrowing the reproducing track width to narrow the reproducing track width, it is possible to increase the recording density particularly in the track width direction. The present invention is a small H
If it is applied to a disc recording / reproducing apparatus such as a DD, it becomes possible to realize a large-capacity disc recording / reproducing apparatus as the recording track density becomes higher.

[Brief description of the drawings]

FIG. 1 is an HD related to a first embodiment of the present invention.
The block diagram which shows the principal part of D.

FIG. 2 is a conceptual diagram for explaining the operation of a head structure and a signal processing circuit related to this embodiment.

FIG. 3 is a signal waveform diagram for explaining operations of a head and a signal processing circuit related to the present embodiment.

FIG. 4 is a signal waveform diagram for explaining operations of a head and a signal processing circuit related to the present embodiment.

FIG. 5 is a signal waveform diagram for explaining operations of a head and a signal processing circuit relating to the present embodiment.

FIG. 6 is a diagram showing the structure of an MR head related to the second embodiment of the invention.

FIG. 7 is a block diagram showing a main part of an HDD according to a third embodiment of the present invention.

FIG. 8 is a block diagram showing a main part of an HDD according to a fourth embodiment of the present invention.

FIG. 9 is a schematic diagram showing a structure of a head tip portion related to the fourth embodiment.

FIG. 10 is a conceptual diagram showing a positional relationship between a head and a recording medium according to the fourth embodiment.

FIG. 11 is a block diagram showing a main part of an HDD according to a fifth embodiment of the present invention.

FIG. 12 is a schematic diagram showing a structure of a head tip portion related to the fifth embodiment.

FIG. 13 is a conceptual diagram showing a positional relationship between a head and a recording medium according to the fifth embodiment.

FIG. 14 is a block diagram showing a main part of an HDD according to a sixth embodiment of the present invention.

FIG. 15 is a schematic diagram showing the structure of the head tip portion related to the sixth embodiment.

FIG. 16 is a conceptual diagram showing a positional relationship between a head and a recording medium according to the sixth embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Disk (recording medium) 2 ... Head (recording / reproducing head or reproducing head) 2a ... Magnetic shield member 3 ... Head amplifier 4 ... Head amplifier 5 ... Delay circuit (normalizing means) 6 ... Level adjusting amplifier (normalization) Means) 7 ... Adder circuit (reproducing signal synthesizing means) 8 ... Read channel (data reproducing circuit) 10 ... Signal processing circuit 12, 32, 52 ... Head (recording / reproducing head or reproducing head) 12a ... Magnetic shield member 12b ... Magnetic shield member 12c ... Magnetic shield member 12d ... Magnetic shield member 17 ... Adder circuit (reproduction signal combining means) 20a to 20k ... Magnetoresistive element 21a to 21c ... Magnetic shield member 20h ... Magnetic having non-MR portion in the middle of the film Resistance element (MR
Membrane) 20i ... Non-MR portion in magnetoresistive element (MR film) 22 ... Coil (magnetic field generating coil for recording) 30 ... Signal processing circuit 40 ... Magnetoresistive element (MR film) Ga, Gb, Gd, Ge, Gj, Gk ... Gap TR ... Track

Claims (14)

[Claims] 1. A magnetic head having a gap is used,
A disc recording / reproducing apparatus for reproducing data from a track of a recording medium, the disc being located on the same track, having a plurality of gaps for detecting a recording magnetic field of the recording medium, wherein each gap has a different gap length. And a magnetic head configured such that the respective reproduction signal outputs corresponding to the recording magnetic field have a predetermined time difference, and the reproduction signals output for each of the gaps of the magnetic head are combined to obtain each of the gap lengths. A magnetic recording / reproducing apparatus comprising: a signal processing unit for generating a reproduction signal corresponding to a narrower gap length. 2. Using a magnetic head having a gap,
A disk recording / reproducing apparatus for reproducing data from a track of a recording medium, the disk recording / reproducing apparatus having first and second gaps located on the same track for detecting a recording magnetic field of the recording medium. Magnetic heads having different gap lengths and different reproduction signal outputs according to the recording magnetic field having a predetermined time difference, and a predetermined normalization process for each reproduction signal corresponding to each gap. And a signal processing unit that executes the reproduction signal to generate a reproduction signal having a gap length corresponding to the difference between the gap lengths of the gaps. 3. A magnetic head having a gap is used,
A disk recording / reproducing apparatus for reproducing data from a track of a recording medium, the disk recording / reproducing apparatus having first and second gaps located on the same track for detecting a recording magnetic field of the recording medium. Magnetic heads having different gap lengths and different reproduction signal outputs according to the recording magnetic field having a predetermined time difference, and among the reproduction signals corresponding to the gaps, the signals are output earlier in time. Delaying means for delaying the reproduced signal according to the predetermined time difference, processing means for executing predetermined processing including amplification processing and polarity inversion processing on the reproduced signal corresponding to each gap, the delaying means and the processing After each processing of the means, it is a reproduction signal corresponding to the difference of each reproduction signal corresponding to each gap, and is a gap signal corresponding to the difference in gap length of each gap. A magnetic recording / reproducing apparatus, comprising: a signal generating means for generating a reproduction signal having a long length. 4. The magnetic head of claim 1, wherein the magnetic head is a magnetoresistive effect reproducing head.
The magnetic recording / reproducing apparatus as described in any one of 1 above. 5. A magnetic head device applied to a magnetic recording / reproducing device for reproducing data from a track of a recording medium, which has a relatively wide gap length by detecting a recording magnetic field recorded on the track. A first gap; and a second gap having a relatively narrow gap length and arranged on the same track as the first gap via a magnetic shield member having a predetermined thickness. And magnetic head device. 6. A disk recording / reproducing apparatus for reproducing data from a track of a recording medium by using a magnetic head having a gap, wherein two reproducing magnetic heads having the same gap length and different track widths are reproduced. A magnetic head, which is arranged along the head moving direction and is arranged so that the reproducing edges on the same side of the two reproducing heads substantially coincide with each other, and a reproducing signal outputted for each gap of the magnetic head are combined. And a signal processing means for generating a reproduction signal corresponding to a track width narrower than the reproduction track width of each gap. 7. A disc recording / reproducing apparatus for reproducing data from a track of a recording medium by using a magnetic head having a gap, the disc recording / reproducing apparatus being located on the same track and for detecting a recording magnetic field of the recording medium. A magnetic head having first and second gaps, the respective gaps having different reproduction track widths, and respective reproduction signal outputs corresponding to recording magnetizations having a predetermined time difference; Of the corresponding reproduction signals, the reproduction signal of the preceding gap is subjected to delay processing to obtain the difference of the reproduction signals, thereby obtaining the reproduction signal of the reproduction track width corresponding to the difference of the reproduction track width of the gaps. A magnetic recording / reproducing apparatus comprising: a signal processing unit for generating. 8. A disk recording / reproducing apparatus for reproducing data from a track of a recording medium by using a magnetic head having a gap, which is located on the same track and is for detecting a recording magnetic field of the recording medium. A magnetic head having first and second gaps, the respective gaps having different reproduction track widths, and respective reproduction signal outputs corresponding to recording magnetizations having a predetermined time difference; Of the corresponding reproduction signals, a delay unit that delays the reproduction signal from the preceding gap according to the predetermined time difference, and a polarity inversion that performs polarity inversion processing on one of the reproduction signals corresponding to the gaps. Means for reproducing the reproduced signal corresponding to the difference between the reproduced signals corresponding to the gaps after the processing of the delay means and the polarity reversing means. A magnetic recording / reproducing apparatus comprising: a signal processing unit that generates a reproduction signal having a reproduction track width corresponding to a difference in reproduction track width of a gap. 9. A disk recording / reproducing apparatus for reproducing data from a track of a recording medium by using a magnetic head having a gap, the disk recording / reproducing apparatus being located on the same track and for detecting a recording magnetic field of the recording medium. The first and second gaps are provided, the reproduction signals from the respective gaps have different reproduction off-track patterns, and the reproduction signal outputs from the respective gap portions according to the recording magnetization have a predetermined time difference. A magnetic head, delay means for delaying the reproduction signal from the preceding gap among the reproduction signals corresponding to the gaps according to the predetermined time difference, and the reproduction signal corresponding to the gaps. Polarity inversion means for executing polarity inversion processing, and after each processing of the delay means and the polarity inversion means, the difference between the reproduction signals corresponding to the gaps And a signal processing unit for generating a reproduction signal having a reproduction off-track pattern corresponding to the difference between the reproduction off-track patterns of the respective gaps. 10. A disk recording / reproducing apparatus for reproducing data from a track of a recording medium by using a magnetic head having a gap, the disk recording / reproducing apparatus being located on the same track and for detecting a recording magnetic field of the recording medium. The reproduction off-track pattern having the first and second gaps and corresponding to one of the gaps has a low-sensitivity portion in the central portion, and the reproduction signal output from each gap portion according to the recording magnetization. A magnetic head configured to have a predetermined time difference, delay means for delaying a reproduction signal from a preceding gap among reproduction signals corresponding to the gaps according to the predetermined time difference, and Polarity inversion means for executing polarity inversion processing on the reproduced signal corresponding to the gap, and after each processing of the delay means and the polarity inversion means, A reproduction signal corresponding to the difference between the reproduction signals corresponding to each of the gaps, and having a track width corresponding to the width of the low-sensitivity portion existing in the reproduction off-track pattern of one of the gaps. A magnetic recording / reproducing apparatus comprising: a signal processing unit. 11. A disc recording / reproducing apparatus for reproducing data from a track of a recording medium by using a magnetic head having a gap, wherein at least three gaps having the same gap length for detecting recording magnetization of the recording medium. The first and second gaps are located on the same line perpendicular to the head movement direction, and the third gap is larger than the sum of the first and second gaps and the reproduction track width. And is arranged in front of or behind the first and second gaps, and the reproduction edge of the reproduction edges of the first and second gaps that does not face each other is the reproduction edge of the third gap and the medium. A magnetic head arranged so as to travel on the same collinear line, a synthesizing means for synthesizing outputs from the first and second gaps, and an output of the synthesizing means or the third A delay means for delaying at least one of the outputs from the gap; a difference between an output from the combining means and the third gap, which is not connected to the delay means, and an output from the delay means; A magnetic recording signal reproducing apparatus, comprising: 12. The magnetic recording / reproducing apparatus according to claim 6, wherein the magnetic head is a magnetoresistive effect reproducing head. 13. A magnetic recording apparatus using a magnetoresistive head as a reproducing head, wherein two magnetoresistive heads arranged along a head moving direction are provided with magnetoresistive elements having equal electrode intervals on both sides, and one of the magnetoresistive elements is used. The element is provided with a conducting portion between the electrodes in addition to the electrodes on both sides, and at least one of an output of a magnetoresistive head having a magnetoresistive element provided with the conducting portion and an output of a magnetoresistive head not having the conducting portion is provided. Delaying means for delaying, and a difference synthesizing means for taking the difference between the output from the head not connected to the delaying means of the magnetoresistive head and the output from the delaying means and outputting the difference. Characteristic magnetic recording signal reproducing device. 14. A disk recording / reproducing device for reproducing data from a track of a recording medium by using a magnetic head having a gap using a magnetoresistive element as a reproducing means, the recording medium being located on the same track. To detect the recording magnetic field, the first gap has a first magnetoresistive element, and the second gap has second and third magnetoresistive elements. Of the reproducing edges of the second and third magnetoresistive elements, the reproducing edge on the side not facing each other runs on the same line as the reproducing edge of the first magnetoresistive element. A magnetic head configured so that the reproduction output from the second and third magnetoresistive elements has a predetermined time difference with respect to the reproduction signal output from the first magnetoresistive element according to From the magnetoresistive element of 3 Combining means for combining forces, delay means for delaying at least one of the output of the combining means and the output from the first magnetoresistive element, and the delay means of the combining means and the first magnetoresistive element A magnetic recording signal reproducing apparatus comprising: a difference synthesizing unit that outputs the difference between the output from the one not connected to and the output of the delay unit.