JP4006819B2 - Magnetoresistive magnetic head and magnetic recording / reproducing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a magnetoresistive head that reproduces an information signal from a magnetic tape, andFor magnetic recording / reproducing deviceRelated.
[0002]
[Prior art]
Magnetic recording / reproducing apparatuses such as video tape recorders, audio tape recorders, and computer data storage systems that use magnetic tape as a recording medium employ a helical scan system to increase recording density and increase capacity. .
[0003]
In a magnetic tape used in the helical scan method, a recording track on which an information signal is recorded is formed to have a predetermined angle (azimuth angle) with respect to the longitudinal direction of the tape.
[0004]
The magnetic head reproduces an information signal from the magnetic tape by tracing the recording track. At this time, in order for the magnetic head to accurately reproduce the information signal from the magnetic tape, it is necessary to perform tracking control so that the magnetic head accurately traces the recording track.
[0005]
[Problems to be solved by the invention]
In order to perform tracking accurately, the traveling system of the magnetic tape, the rotational phase of the rotating drum, and the like must be precisely controlled, which complicates the configuration of the apparatus. Also in the magnetic tape, in order to allow the magnetic head to accurately trace the recording track, it is necessary to widen the recording track width to some extent, which hinders high recording density.
[0006]
On the other hand, a so-called non-tracking type magnetic recording / reproducing apparatus capable of reproducing information signals from a magnetic tape without performing tracking control has been proposed.
[0007]
In a non-tracking magnetic recording / reproducing apparatus, a plurality of, for example, two reproducing magnetic heads are used for one recording magnetic head, and the information signal on the recording track is detected by tracing the recording track at double density. Then, an information signal is reproduced from the magnetic tape by synthesizing the obtained signals.
[0008]
In such a non-tracking magnetic recording / reproducing apparatus, a plurality of magnetic heads are mounted on a rotating drum and mounted on different head bases. Therefore, it is difficult to mount a plurality of magnetic heads on the rotating drum. There was a problem. Further, when mounting a plurality of magnetic heads on a rotating drum, there is a problem that the positional adjustment between the magnetic heads becomes complicated.
[0009]
  The present invention has been proposed in view of the conventional situation as described above, and saves the magnetic head mounted on the rotating drum and facilitates the mutual positioning of the plurality of magnetic heads. An object is to provide an effect type magnetic head and a magnetic recording / reproducing apparatus.
[0010]
[Means for Solving the Problems]
  The present inventionIn a magnetoresistive effect type magnetic head mounted on a helical scan type magnetic recording / reproducing apparatus using a magnetic tape as a recording medium,A thin-film magnetoresistive element is sandwiched between a pair of soft magnetic bodies via an insulating layerTwoMagnetoresistive headHavethe aboveTwoThe magnetoresistive headThe magnetic tape has the same azimuth angle inclined by a certain angle with respect to the traveling direction of the magnetic tape and is integrally formed in parallel with each other at a predetermined interval in the film thickness direction of the magnetoresistive effect element.Features.
  The magnetoresistive element is formed with a length larger than the track pitch of the recording track formed on the magnetic tape and smaller than twice the track pitch.It is desirable to do.
[0011]
  In the magnetoresistance effect type magnetic head according to the present invention as described above,TwoSince the magnetoresistive effect type magnetic head part is integrally formed,TwoThe magnetic head is reduced in size as compared with the case where the magnetic head is individually formed.
[0012]
  The present invention also provides:Using magnetic tape as a recording mediumIn a helical scan type magnetic recording / reproducing apparatus, a substantially cylindrical rotating drum and a thin-film magnetoresistive element mounted on the rotating drum are sandwiched between a pair of soft magnetic bodies via an insulating layer.TwoMagnetoresistive headThe two magnetoresistive heads have the same azimuth angle inclined at a certain angle with respect to the running direction of the magnetic tape and are parallel to each other in the film thickness direction of the magnetoresistive element. Separated byA first magnetoresistive effect type magnetic head formed integrally with the rotating drum, and a thin film magnetoresistive effect element is sandwiched between a pair of soft magnetic bodies via an insulating layer.TwoMagnetoresistive headThe two magnetoresistive heads have the same azimuth angle inclined at a certain angle with respect to the running direction of the magnetic tape and are parallel to each other in the film thickness direction of the magnetoresistive element. Separated byAnd a second magnetoresistive effect magnetic head formed integrally, and an information signal is reproduced from the magnetic tape by a non-tracking method.
  Further, the first magnetoresistance effect type magnetic head and the second magnetoresistance effect type magnetic head have the azimuth angles opposite to each other..
[0013]
  In the magnetic recording / reproducing apparatus according to the present invention as described above,TwoA first magnetoresistive effect type magnetic head in which magnetoresistive effect type magnetic head portions are formed integrally with a predetermined interval so as to have the same azimuth angle; and a second magnetoresistive effect type magnetic head; TheBy providingInformation signals are reproduced from the magnetic tape without tracking control. In the magnetic recording / reproducing apparatus, the first and second magnetoresistive heads areTwoMagnetoresistive magnetic headIs integrally formedTherefore, the magnetic head is reduced in size, and the mutual position determination of the magnetic head is facilitated.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0017]
The magnetic recording / reproducing apparatus according to the present invention is a magnetic recording / reproducing apparatus using a magnetic tape as a recording medium, and is used as, for example, a video tape recorder, an audio tape recorder, or a computer data storage system. The magnetic recording / reproducing apparatus according to the present invention is a helical scan type magnetic recording / reproducing apparatus that performs recording / reproduction using a rotating drum, and a magnetoresistive effect type magnetic head as a reproducing magnetic head mounted on the rotating drum. (Hereinafter referred to as MR head).
[0018]
FIG. 1 shows a configuration example of a rotating drum device mounted on a magnetic recording / reproducing apparatus to which the present invention is applied. FIG. 1 is a perspective view schematically showing the rotary drum device 1. As shown in FIG. 1, the rotary drum device 1 includes a cylindrical fixed drum 2, a cylindrical rotary drum 3, a motor 4 that rotationally drives the rotary drum 3, and a pair of inductives mounted on the rotary drum 3. And a pair of MR heads 6 a and 6 b mounted on the rotary drum 3.
[0019]
Here, a so-called upper drum type rotary drum device 1 in which the rotary drum 3 is arranged on the fixed drum 2 is taken as an example, but the present invention is widely applied to a helical scan type magnetic recording / reproducing device. The type of the rotary drum device 1 is not particularly limited. For example, a so-called medium drum type rotary drum device 1 in which a rotary drum 3 is sandwiched between a pair of fixed drums 2 may be used.
[0020]
In the rotary drum device 1, the fixed drum 2 is a drum that is held without rotating. A lead guide portion 8 is formed on the side surface of the fixed drum 2 along the traveling direction of the magnetic tape 7. As will be described later, the magnetic tape 7 travels along the lead guide portion 8 during recording and reproduction. The rotating drum 3 is arranged so that the fixed drum 2 and the central axis coincide with each other.
[0021]
The rotary drum 3 is a drum that is driven to rotate at a predetermined rotational speed by the motor 4 during recording / reproduction on the magnetic tape 7. The rotating drum 3 is formed in a cylindrical shape having substantially the same diameter as the fixed drum 2 and is arranged so that the central axis thereof coincides with the fixed drum 2. A pair of inductive magnetic heads 5a and 5b and a pair of MR heads 6a and 6b are mounted on the side of the rotating drum 3 facing the fixed drum 2.
[0022]
The inductive magnetic heads 5a and 5b are recording magnetic heads in which a pair of magnetic cores are joined via a magnetic gap, and a coil is wound around the magnetic cores. Used for. These inductive magnetic heads 5 a and 5 b are mounted on the rotating drum 3 such that their magnetic gap portions protrude from the outer periphery of the rotating drum 3. The inductive magnetic heads 5a and 5b are set so that the azimuth angles are opposite to each other so that guard bandless recording is performed on the magnetic tape 7 with a predetermined azimuth angle.
[0023]
As these inductive magnetic heads 5a and 5b, any of the known recording magnetic heads employed in the conventional helical scan type magnetic recording / reproducing apparatus can be used. Specifically, the magnetic core is composed of a soft magnetic material such as ferrite and a metal magnetic film formed on the soft magnetic material, and the pair of magnetic cores has a metal magnetic film sandwiching a magnetic gap. A so-called MIG (Metal In Gap) type magnetic head that is joined so as to face each other is particularly suitable.
[0024]
The MR heads 6a and 6b are magnetic heads that detect information signals from the magnetic tape 7 using the magnetoresistive effect, and are reproducing magnetic heads. In general, an MR head is suitable for high-density recording because it has higher sensitivity and higher reproduction output than an inductive magnetic head that performs recording and reproduction using electromagnetic induction. Therefore, higher recording density can be achieved by using the MR heads 6a and 6b as reproducing magnetic heads.
[0025]
These MR heads 6a and 6b have an azimuth angle similar to that of the inductive magnetic heads 5a and 5b so that a magnetic signal recorded on the magnetic tape 7 with a predetermined azimuth angle can be detected. They are set to be opposite to each other.
[0026]
These MR heads 6 a and 6 b are mounted on the rotating drum 3 such that the angle formed with respect to the center of the rotating drum 3 is 180 ° and the MR element portion protrudes from the outer periphery of the rotating drum 3.
[0027]
Hereinafter, the MR heads 6a and 6b will be described. The MR head 6a and the MR head 6b have substantially the same configuration. Therefore, in the following description, these MR heads 6a and 6b are collectively referred to as an MR head 6.
[0028]
As shown in FIGS. 2 and 3, the MR head 6 includes a first MR head portion 10 and a second MR head portion 11 that are integrally formed. FIG. 2 is a perspective view showing one configuration example of the MR head 6. FIG. 3 shows the first and second MR head portions 10 and 11 and the vicinity thereof in an enlarged manner.
[0029]
The first MR head unit 10 includes a pair of magnetic shields 12 and 13 made of a soft magnetic material, a thin film MR element unit 15 sandwiched between the pair of magnetic shields 12 and 13 via an insulating film 14, and an MR element. Permanent magnet films 16a and 16b disposed on both sides of the element section 15 and conductor sections 17a and 17b connected to the permanent magnet films 16a and 16b, respectively.
[0030]
The second MR head unit 11 includes a pair of magnetic shields 12 and 18 made of a soft magnetic material, an MR element unit 20 sandwiched between the pair of magnetic shields 12 and 18 via an insulating film 19, and an MR element unit 20 Permanent magnet films 21a and 21b respectively disposed on both sides of the magnets and conductor portions (not shown) connected to the permanent magnet films 21a and 21b.
[0031]
In the MR head 6, the magnetic shield 12 is a magnetic shield shared by the first MR head unit 10 and the second MR head unit 11. In the MR head 6, the first MR head portion 10 and the second MR head portion 11 are arranged with a predetermined interval k in the film thickness direction of the MR element portion. Further, as shown in FIGS. 2 and 3, the first MR head unit 10 and the second MR head unit 11 have a predetermined direction with respect to the sliding direction of the MR head 6 with respect to the magnetic tape 7 indicated by the arrow D. An azimuth angle θ is set. Further, the sliding direction front end side and sliding direction rear end side of the MR head 6 are guarded by a pair of guard members 22a and 22b. For these guard members 22a and 22b, nonmagnetic materials having excellent wear resistance are used.
[0032]
In the first MR head unit 10, the MR element unit 15 includes a MR element having a magnetoresistive effect, a SAL (Soft Adjacent Layer) film, and an insulator film disposed between the MR element and the SAL film. Being done. The MR element is made of a soft magnetic material such as Ni—Fe whose resistance value changes depending on the magnitude of the external magnetic field due to the anisotropic magnetoresistive effect (AMR). The SAL film is for applying a vertical bias magnetic field to the MR element by a so-called SAL bias method, and is made of a magnetic material having a low coercive force and a high permeability such as permalloy. The insulator film insulates between the MR element and the SAL film and prevents electrical shunt loss, and is made of an insulating material such as Ta.
[0033]
The permanent magnet films 16a and 16b disposed on both sides of the MR element portion 15 are for applying a horizontal bias magnetic field to the MR element, and are disposed so as to be in contact with both sides of the MR element. It is structured. These permanent magnet films 16a and 16b are made of a magnetic material having a large coercive force and conductivity, such as Co—Ni—Pt or Co—Cr—Pt.
[0034]
The conductor portions 17a and 17b connected to the permanent magnet films 16a and 16b are formed on the side surfaces of one magnetic shield 13 so that their end portions are exposed to the outside. , 17b serve as external terminals 23a, 23b for supplying a sense current to the MR element from the outside. That is, a sense current is supplied to the MR element formed in the MR element portion 15 from the external terminals 23a and 23b through the conductor portions 17a and 17b and the permanent magnet films 16a and 16b.
[0035]
In the first MR head portion 10, the MR element portion 15 is formed so that the planar shape is substantially rectangular as shown in FIG. It is sandwiched by a pair of magnetic shields 12 and 13 via an insulator 14 so that it is substantially vertical and one side surface of the sliding surface 24 is exposed. In this MR head 6, the MR element portion 15 becomes a magnetic sensitive portion for detecting the magnetic field from the magnetic tape 7, and the length t of the magnetic sensitive portion is larger than the track pitch Tp of the recording track, It is made smaller than twice Tp.
[0036]
In the above description, the first MR head unit 10 has been described. However, since the second MR head unit 11 has the same configuration as the first MR head unit 10, the second MR head unit 11 has the same configuration. Description of is omitted.
[0037]
Further, as shown in FIGS. 2 and 3, the MR head 6 has the first MR head portion 10 and the second MR head portion 11 arranged in the film thickness direction of the MR element. Electrical connection between the external terminals and the external electrodes of the first MR head unit 10 and the second MR head unit 11 can be easily performed.
[0038]
Such an MR head 6 is mounted on the rotating drum 3 so that at least a part protrudes from the outer peripheral portion of the rotating drum 3. Further, the MR head 6 has a sliding surface 24 cylindrically ground along the sliding direction of the MR head 6 with respect to the magnetic tape 7 indicated by an arrow D in FIGS. Cylindrical grinding is performed along a direction orthogonal to the direction.
[0039]
Then, as shown in FIG. 5, the magnetic recording / reproducing apparatus slides the magnetic tape 7 on such a rotating drum apparatus 1 to record data on the magnetic tape 7 and reproduce data from the magnetic tape 7. I do. Here, FIG. 5 is a plan view showing an outline of the magnetic tape feeding mechanism 30 including the rotary drum device 1. Specifically, at the time of recording / reproducing, as shown in FIG. 5, the magnetic tape 7 is sent from the supply reel 31 through the guide rollers 32 and 33 so as to be wound around the rotary drum device 1. Recording / playback is performed.
[0040]
Here, when data is recorded on the magnetic tape 7, the pair of inductive magnetic heads 5a and 5b and the magnetic tape 7 are slid, and guard bandless recording is performed by these inductive magnetic heads 5a and 5b.
[0041]
When reproducing data from the magnetic tape 7, the pair of MR heads 6a, 6b and the magnetic tape 7 are slid, and the data recorded by the pair of inductive magnetic heads 5a, 5b is transferred to these MR heads. Playback is performed by 6a and 6b.
[0042]
In this rotary drum device 1, the MR heads 6 a and 6 b include a plurality of MR head portions and a pair of MR heads 6 a and 6 b having different azimuth angles, so that when reproducing information signals from the magnetic tape 7 It is possible to reproduce the information signal from the magnetic tape 7 without performing tracking control.
[0043]
For example, as shown in FIG. 6, recording tracks TA1, TB1, TA2, TB2... On which data is recorded are formed on the magnetic tape 7. Here, the tracks TA1, TA2, TA3,... Are azimuth angles that can be reproduced by the MR head 6a, and the tracks TB1, TB2, TB3 are azimuth angles that can be reproduced by the MR head 6b.
[0044]
Here, the recording TA azimuth angle track TA2 that can be reproduced by the MR head 6a will be described as an example. The MR head 6a has two MR head portions. One MR head portion first scans on the magnetic tape 7 along the locus (1), and then on the magnetic tape 7 after one rotation of the rotating drum. Is scanned along locus (2). Thereafter, after each rotation, one MR head scans on the magnetic tape 7 as locus (3) and locus (4). At this time, the trajectories {circle around (1)}, {circle around (2)}, {circle around (3)}, {circle around (4)} are shifted by, for example, one track pitch Tp.
[0045]
By performing such scanning, one of the MR heads of the MR head 6a is scanned from the MR head 6a in the scanning of each locus (1), (2), (3), and (4). Reproduction outputs as shown in b), (c), and (d) are obtained. Here, FIG. 7A shows a reproduction output in the scanning of the locus (1). FIG. 7B shows a reproduction output in the scanning of the locus (2). FIG. 7C shows a reproduction output in the scanning of the locus (3). FIG. 7D shows a reproduction output in the scanning of the locus (4).
[0046]
That is, in the scanning of the locus (1), as shown in FIG. 7A, the signal of the track TA2 is first reproduced for a while, and the signal of the track TA1 is reproduced in the remaining portion. In the scanning of the locus (2), as shown in FIG. 7B, the signal of the track TA2 is reproduced first, and the signal of the track TA1 is reproduced a little in the latter half. In the scanning of the locus (3), as shown in FIG. 7C, the signal of the track TA3 is first reproduced for a while, and the signal of the track TA2 is reproduced in the remaining portion. In the scanning of the locus (4), as shown in FIG. 7 (d), the signal of the track TA3 is reproduced first, and the signal of the track TA2 is reproduced a little in the latter half.
[0047]
As described above, the signal recorded on the track TA2 is divided into several parts and reproduced. A signal recorded on the track TA2 can be reproduced by performing predetermined signal processing on the divided and reproduced signal.
[0048]
Similarly, the other MR head portion of the MR head 6a scans on the magnetic tape 7. At this time, in the MR head 6a, when the interval between the two MR head portions is k and the azimuth angle of the MR head 6a is θ, (k × sin θ) is equal to an integral multiple n × Tp of the track pitch Tp. Thus, it is preferable that the interval k between the two MR head portions is determined. For example, when (k × sin θ) = Tp, one MR head part of the MR head 6a and the other MR head part respectively scan a place separated by about 1 track pitch. That is, when one MR head part is scanning along the locus (2), the other MR head part is scanning along the locus II substantially the same as the locus (1). Further, when one MR head part is scanning along the locus (3), the other MR head part is scanned along the locus III substantially the same as the locus (2).
[0049]
Therefore, for example, even if one of the MR heads scans along the locus (2), even if a signal detection omission occurs, the other MR head portion almost follows the locus (2) after one rotation of the rotating drum. Since scanning is performed with the same locus III, a signal that is not detected by one MR head can be detected by the other MR head.
[0050]
Thus, by determining the interval k between the two MR head portions of the MR head 6a as described above, when reproducing signals from the magnetic tape 7 using the MR head 6a in a non-tracking manner, the magnetic head 7 Can be reproduced without leakage. Specifically, for example, when Tp is 5 μm and θ is 20 °, k is determined to be 14.6 μm.
[0051]
The MR head 6b can also reproduce the signal from the magnetic tape 7 in the same manner as the MR head 6a. Therefore, the rotary drum device 1 can reproduce the information signal from the magnetic tape 7 as described above without performing tracking control.
[0052]
Recording and reproduction by the rotating drum device 1 will be described with reference to FIG. 8 showing an outline of the circuit configuration of the rotating drum device 1 and its peripheral circuits.
[0053]
When data is recorded on the magnetic tape 7 using the rotary drum device 1, first, a current is supplied to the drive coil of the motor 4, thereby rotating the rotary drum 3. Then, while the rotating drum 3 is rotating, the recording signal from the external circuit 40 is supplied to the encoder 41 as shown in FIG.
[0054]
The encoder 41 supplied with the recording signal from the external circuit 40 encodes the recording signal and adds a predetermined error correction code. That is, the encoder 41 functions as an error correction code adding unit that encodes a recording signal from the external circuit 40 and adds an error correction code to data to be recorded on the magnetic tape 7. The data to which the error correction code is added by the encoder 41 is supplied to the modulation circuit 42.
[0055]
The modulation circuit 42 modulates the data sent from the encoder 41 into data composed of, for example, a DC-free code string.
[0056]
The data comprising the DC-free code string output from the modulation circuit 42 is supplied to the recording amplifier 43a or the recording amplifier 43b. Here, the modulation circuit 42 supplies data to the recording amplifier 43a or the recording amplifier 43b in synchronization with the rotation of the rotary drum 3. That is, the modulation circuit 42 supplies data to the recording amplifier 43a corresponding to the inductive magnetic head 5a at the timing when the data is recorded by one inductive magnetic head 5a, and the other inductive magnetic head 5a. At the timing of recording data in 5b, the data is supplied to the recording amplifier 43b corresponding to the inductive magnetic head 5b.
[0057]
Then, the recording amplifier 43a to which the data composed of the DC-free code string is supplied from the modulation circuit 42 amplifies the recording signal corresponding to the data to a predetermined level and supplies the amplified signal to the signal transmission ring 44a. Similarly, the recording amplifier 43b supplied with data including a DC-free code string from the modulation circuit 42 amplifies a recording signal corresponding to the data to a predetermined level and supplies the amplified signal to the signal transmission ring 44b.
[0058]
Then, the recording signal supplied to the signal transmission ring 44a corresponding to one inductive magnetic head 5a is transmitted to the signal transmission ring 43a in a non-contact manner. The recording signal transmitted to the signal transmission ring 45a is supplied to the inductive magnetic head 5a, and data is recorded on the magnetic tape 7 by the inductive magnetic head 5a.
[0059]
Similarly, the recording signal supplied to the signal transmission ring 44b corresponding to the other inductive magnetic head 5b is transmitted to the signal transmission ring 45b in a non-contact manner. The recording signal transmitted to the signal transmission ring 45b is supplied to the inductive magnetic head 5b, and data is recorded on the magnetic tape 7 by the inductive magnetic head 5b.
[0060]
On the other hand, when data is reproduced from the magnetic tape 7 using the rotating drum device 1, first, a current is supplied to the driving coil of the motor 4, as in the case of data recording. Driven by rotation. Then, with the rotating drum 3 rotating, a high frequency current is supplied from the oscillator 46 to the power drive 47 as shown in FIG. The high frequency current from the oscillator 46 is converted into a predetermined alternating current by the power drive 47 and then supplied to the power transmission ring 48.
[0061]
The alternating current supplied to the power transmission ring 48 is transmitted to the power transmission ring 49 in a non-contact manner. Then, the alternating current transmitted to the power transmission ring 49 is rectified by the rectifier 50 to be a direct current and supplied to the regulator 51, and the direct current is set to a predetermined voltage by the regulator 51.
[0062]
The current set to a predetermined voltage by the regulator 51 is supplied as a sense current to the pair of MR heads 6a and 6b.
[0063]
The MR head 6a is connected to a reproducing amplifier 52a that detects a signal from the MR head 6a. The current from the regulator 51 is also supplied to the reproducing amplifier 52a. The MR head 6b is connected to a reproducing amplifier 52b that detects a signal from the MR head 6b, and the current from the regulator 51 is also supplied to the reproducing amplifier 52b.
[0064]
Here, the MR head 6a has two MR head portions 10a and 11a, and each of the MR head portions 10a and 11a includes an MR element whose resistance value changes depending on the magnitude of the external magnetic field. In the MR head portions 10a and 11a, the resistance value of the MR element is changed by the signal magnetic field from the magnetic tape 7, and as a result, a voltage change appears in the sense current. The reproduction amplifier 52a detects this voltage change and outputs a signal corresponding to the voltage change as a reproduction signal.
[0065]
The reproduction signal from the reproduction amplifier 52a is supplied to the signal transmission ring 53a, and this reproduction signal is transmitted to the signal transmission ring 54a in a non-contact manner.
[0066]
Then, the reproduction signal transmitted to the signal transmission ring 54a is supplied to the reproduction amplifier 55a, amplified by the reproduction amplifier 55a, and then supplied to the detection circuit 56a. The detection circuit 56a detects data composed of a code string from the reproduction signal supplied from the reproduction amplifier 55a. Here, the data recorded on the magnetic tape 7 is data converted into a DC-free code string. Therefore, the data detected by the detection circuit 56a is data composed of a DC-free code string.
[0067]
The data detected by the detection circuit is supplied as reproduction data A to the signal processing circuit 57, and processing such as error correction processing is performed.
[0068]
Similarly, the MR head 6b has two MR head portions 10b and 11b, and each of the MR head portions 10b and 11b includes an MR element whose resistance value varies depending on the magnitude of the external magnetic field. The MR head portions 10b and 11b are adapted to cause a voltage change in the sense current due to a change in the resistance value of the MR element due to the signal magnetic field from the magnetic tape 7. Then, the reproduction amplifier 52b detects this voltage change and outputs a signal corresponding to the voltage change as a reproduction signal.
[0069]
Then, the reproduction signal from the reproduction amplifier 52b is supplied to the signal transmission ring 53b, and this reproduction signal is transmitted to the signal transmission ring 54b in a non-contact manner.
[0070]
Then, the reproduction signal transmitted to the signal transmission ring 54b is supplied to the reproduction amplifier 55b, amplified by the reproduction amplifier 55b, and then supplied to the detection circuit 56b. The detection circuit 56b detects data composed of a code string from the reproduction signal supplied from the reproduction amplifier 55b.
[0071]
The data detected by the detection circuit 56b is supplied to the signal processing circuit 57 as reproduction data B, and processing such as error correction processing is performed together with the reproduction data A.
[0072]
By performing error correction processing in this way, even if there is a loss in the reproduced signal, the original data can be reproduced if there are not too many missing reproduction signals.
[0073]
In the case of the circuit configuration as shown in FIG. 8, the pair of inductive magnetic heads 5a and 5b, the pair of MR heads 6a and 6b, the rectifier 50, the regulator 51, and the reproducing amplifiers 52a and 52b And rotates together with the rotating drum 3. On the other hand, the encoder 41, the modulation circuit 42, the recording amplifiers 43a and 43b, the oscillator 46, the power drive 47, the reproduction amplifiers 55a and 55b, the detection circuits 46a and 56b, and the signal processing circuit 57 are fixed to the rotary drum device 1. The external circuit is arranged in a part or configured separately from the rotary drum device 1.
[0074]
Then, the magnetic tape 7 recorded and reproduced by the rotary drum device 1 is sent to the take-up roll 38 through the guide rollers 34 and 35, the capstan 36, and the guide roller 37 as shown in FIG. That is, the magnetic tape 7 is fed at a predetermined tension and speed by a capstan 36 that is rotationally driven by a capstan motor 39, and the inductive magnetic heads 5a, 5b and MR mounted on the rotary drum 3 that is rotationally driven. After the heads 6 a and 6 b are brought into contact with a predetermined contact pressure and slid, they are taken up by a take-up roll 38.
[0075]
Thus, in this rotary drum device 1, the capstan 38 that is rotationally driven by the capstan motor 39 contacts the inductive magnetic heads 5 a and 5 b and the MR heads 6 a and 6 b and the magnetic tape 7. It functions as a pressure control means.
[0076]
Further, when the magnetic tape 7 is fed in this way, the rotary drum 3 is rotationally driven by the motor 4 as indicated by an arrow A in FIG. On the other hand, the magnetic tape 7 is fed along the lead guide portion 8 of the fixed drum 2 so as to slide obliquely with respect to the fixed drum 2 and the rotary drum 3. That is, the magnetic tape 7 is sent along the lead guide portion 8 so as to be in sliding contact with the fixed drum 2 and the rotary drum 3 from the tape inlet side as indicated by an arrow B in FIG. 1 is sent to the tape outlet side as indicated by an arrow C in FIG.
[0077]
As described above, this magnetic recording / reproducing apparatus uses a pair of MR heads 6a and 6b in which a plurality of MR heads are integrally formed, so that information signals are reproduced from the magnetic tape 7 by a non-tracking method. Can be performed.
[0078]
Hereinafter, a method for manufacturing such an MR head 6 will be described.
[0079]
First, a disk-shaped first substrate 12 is prepared. As will be described later, since a large number of MR head portions are formed on both surfaces of the first substrate 12, the surface is subjected to mirror surface treatment in order to improve the surface roughness. The first substrate 12 serves as a lower layer shield of the MR head portion, and a hard soft magnetic material is used. Specific examples of the hard soft magnetic material include Ni—Zn polycrystalline ferrite.
[0080]
Next, as shown in FIGS. 9 and 10, an insulating film 14 serving as a lower layer gap is formed by sputtering or the like on the first substrate 12 having a mirror-finished surface. As a material of the insulating film 14, for example, Al is considered in view of insulating characteristics and wear resistance.₂O_ThreeEtc. are suitable.
[0081]
Next, as shown in FIGS. 11 and 12, an MR element thin film 15a to be the MR element 15 is formed on the first insulating film. As described above, the MR element unit 15 includes an MR element and a soft magnetic film (so-called SAL film) for applying a bias magnetic field to the MR element in order to apply a bias magnetic field to the MR element by a so-called SAL bias method. Are stacked via an insulating film. As a material of the MR element having a magnetoresistive effect, for example, Ni—Fe or the like can be given. Examples of the material of the soft magnetic film that applies a bias magnetic field to the MR element include NiFeNb. The bias system of the MR element section 15 and the material of each film constituting the MR element section 15 are not limited to this, and can be arbitrarily changed according to the requirements of the system and the like.
[0082]
Next, as shown in FIGS. 13, 14, and 15, permanent magnet films 16 a and 16 b are formed on both ends of the portion to be the MR element portion 15. The MR elements are magnetically stabilized by the permanent magnet films 16a and 16b. 14 and 15 and FIGS. 16 to 21 described later, the portion corresponding to one MR head portion 10, that is, the portion of a circle A in FIG. 13 is shown in an enlarged manner.
[0083]
In order to form the permanent magnet films 16a and 16b, first, a resist is coated on the MR element thin film 15a, and a resist pattern in which only the portions that become the permanent magnet films 16a and 16b are removed by photolithography. Form. Specifically, a resist pattern having two substantially rectangular openings arranged in the longitudinal direction with respect to one MR head portion. Next, etching is performed using the resist pattern as a mask, and the MR element portion thin film 15a exposed from the mask is removed.
[0084]
Next, with the resist pattern remaining, permanent magnet films 16a and 16b are formed on the entire surface by sputtering or the like. As a material of the permanent magnet films 16a and 16b, a magnetic material having a large coercive force such as Co—Ni—Pt, Co—Cr—Pt, or the like and having conductivity is used. Finally, by removing the resist together with the permanent magnet films 16a and 16b formed on the resist, the permanent magnet films 16a and 16b having a predetermined pattern are embedded in the MR element thin film 15a.
[0085]
Next, as shown in FIGS. 16 and 17, the MR element portion 15 and conductor portions 17a and 17b for supplying a sense current to the MR element portion 15 are formed. Specifically, in order to form the conductor portions 17a and 17b, first, a resist is applied on the MR element portion thin film 15a, and a portion that finally becomes the MR element portion 15 and the conductor portion 17a are formed by photolithography. , 17b and a resist pattern in which the resist remains only in the portions where the permanent magnet films 16a, 16b are formed. The portions to be the conductor portions 17a and 17b have a substantially rectangular shape, and one end portion in the longitudinal direction is connected to the permanent magnet films 16a and 16b. Further, a portion between the permanent magnet film 16a and the permanent magnet film 16b is a portion that becomes an MR element portion. Next, etching is performed using the resist pattern as a mask, and the MR element portion thin film 15a exposed from the mask is removed.
[0086]
Next, the portions to be the conductor portions 17a and 17b are replaced with a conductive film having a smaller electric resistance. First, a resist is applied, and a resist pattern is formed by removing the resist only in the portions to be the conductor portions 17a and 17b by photolithography. Next, etching is performed using this resist pattern as a mask, and the MR element portion thin film 15a in the portions to be the conductor portions 17a and 17b exposed from the mask is removed. After removing portions of the MR element portion thin film 15a to be the conductor portions 17a and 17b, a conductive film is formed while the resist pattern remains. Examples of the material for the conductive film include Ti and Cu. Next, by removing the resist together with the conductive film formed on the resist, the conductive film is formed on the conductor portions 17a and 17b.
[0087]
Next, as shown in FIGS. 18 and 19, an insulating film 14 to be an upper layer gap is formed by sputtering or the like.
[0088]
Next, as shown in FIGS. 20 and 21, external terminals 23a and 23b for electrical connection with the outside are formed at the ends of the conductor portions 17a and 17b. Specifically, in order to form the external terminals 23a and 23b, first, a resist is applied, and a resist pattern in which the resist is removed only from the portions that become the external terminals 23a and 23b is formed by photolithography. The portions where the external terminals 23a and 23b are formed are the ends of the conductor portions 17a and 17b that are not connected to the permanent magnet films 16a and 16b in the longitudinal direction. Next, using the resist as a mask, the second insulating film 14b exposed from the mask is removed by etching.
[0089]
Next, a conductive film for external terminals is formed with the resist pattern remaining. Specifically, for example, Cu and Au are formed in this order by sputtering or the like to form a conductive film for external terminals. Next, by removing the resist together with the conductive film for external terminals formed on the resist, the external terminals 23a and 23b are formed at the ends of the conductor portions 17a and 17b.
[0090]
Through the above steps, as shown in FIG. 22, a number of MR head portions 10 are formed on one surface of the first substrate 12.
[0091]
Then, as shown in FIG. 23, the MR head portion 11 is formed on the other surface of the first substrate 12 in the same manner as the MR head portion 10 is formed. In this case, the position of the MR head portion 10 formed on one surface of the first substrate 12 and the position of the MR head 11 portion formed on the other surface of the first substrate 12 are the same position. In addition, it is necessary to perform sufficient alignment.
[0092]
With the above process, the thin film process for forming the MR head portion on both surfaces of the first substrate 12 is completed.
[0093]
Next, the substrate is cut in the horizontal direction for each MR head portion, and a plurality of MR head portions are arranged in a horizontal row on the substrate as shown in FIGS. Hereinafter, a structure in which a plurality of MR head portions are arranged in a horizontal row on the substrate will be referred to as an MR head portion row.
[0094]
Then, as shown in FIG. 26, the second substrate 13 is pasted on one surface of the first substrate 12 cut out in the MR head section row, and the third substrate 13 is disposed on the other surface of the first substrate 12. The substrate 18 is affixed. A hard soft magnetic material is used for the second substrate 13 and the third substrate 18. Specific examples of the hard soft magnetic material include Ni—Zn polycrystalline ferrite. Here, the second substrate 13 becomes an upper layer shield of the MR head unit 10, and the third substrate 18 becomes an upper layer shield of the MR head unit 11. For bonding the second substrate 13 and the third substrate 18, for example, an adhesive such as a resin is used. At this time, as shown in FIG. 26, the lengths of the second substrate 13 and the third substrate 18 are made shorter than the length of the first substrate 12 to expose the external terminals 23a and 23b of the MR head unit 10. Thus, connection to the external terminals 23a and 23b is performed.
[0095]
Next, as shown in FIG. 27, in order to divide the MR head part row individually, the MR head part row is cut for each MR head part. As shown in FIG. 27, the cutting direction is not perpendicular to the surface on which the MR head portion is formed, but is cut at a predetermined angle θ. What is necessary is just to change this cutting angle according to the system to be used.
[0096]
Next, as shown in FIG. 28, a pair of guard members 22a and 22b are attached to the MR head portions cut individually. The guard material 22a is attached to the front end side of the MR head 6 in the sliding direction, and the guard material 22b is attached to the rear end side of the MR head 6 in the sliding direction. For these guard members 22a and 22b, nonmagnetic materials having excellent wear resistance are used. Specific examples of the magnetic material having excellent wear resistance include alumina-titanium-carbite.
[0097]
Finally, apply grinding to the sliding surface. By making the shape arc, the MR head 6 as shown in FIGS. 2 and 3 is completed. At this time, the side surface on the sliding surface side of the MR element portion is exposed to the sliding surface 24.
[0098]
【The invention's effect】
In the magnetoresistive effect type magnetic head of the present invention, since the plurality of MR head portions are integrally formed, the magnetic head can be reduced in size.
[0099]
Moreover, in the magnetic recording / reproducing apparatus of the present invention, since the MR head formed by integrally forming a plurality of MR head portions is mounted, the space of the apparatus can be saved. Furthermore, since this magnetic recording / reproducing apparatus is equipped with a pair of MR heads having different azimuth angles, information signals can be reproduced from the magnetic tape by non-tracking. In this magnetic recording / reproducing apparatus, since the MR head is used as the reproducing magnetic head, high-density recording can be achieved.
[Brief description of the drawings]
FIG. 1 is a perspective view schematically showing a configuration example of a rotating drum device mounted on a magnetic recording / reproducing apparatus to which the present invention is applied.
FIG. 2 is a perspective view showing an example of an MR head mounted on the rotating drum.
FIG. 3 is a plan view of the MR head as viewed from the magnetic tape sliding surface side.
FIG. 4 is a diagram schematically showing how data is reproduced from a magnetic tape using an MR head.
FIG. 5 is a plan view schematically showing a configuration example of a magnetic tape feeding mechanism including the rotating drum device.
FIG. 6 is a diagram showing a scanning trajectory of the MR head during non-tracking reproduction.
FIG. 7 is a diagram showing a reproduction output at the time of non-tracking reproduction.
FIG. 8 is a diagram showing a schematic circuit configuration of the rotary drum device and its peripheral circuits.
FIG. 9 is a diagram for explaining a method of manufacturing an MR head, and is a plan view showing a state in which a first insulating film is formed on a first substrate.
FIG. 10 shows X in FIG.₁-X₂It is sectional drawing in a line.
FIG. 11 is a diagram for explaining a method of manufacturing an MR head, and is a plan view showing a state in which a thin film for an MR element is formed.
FIG. 12 shows X in FIG._Three-X_FourIt is sectional drawing in a line.
FIG. 13 is a diagram for explaining a method of manufacturing an MR head, and is a plan view showing a state in which a resist pattern is formed on a thin film for MR element portion.
FIG. 14 is a diagram for explaining a method of manufacturing an MR head, and is a plan view showing a state in which a permanent magnet film is formed.
FIG. 15: X in FIG._Five-X₆It is sectional drawing in a line.
FIG. 16 is a diagram for explaining a method of manufacturing an MR head, and is a plan view showing a state in which an MR element part and a lead conductor are further formed.
FIG. 17: X in FIG.₇-X₈It is sectional drawing in a line.
FIG. 18 is a diagram for explaining a method of manufacturing an MR head, and is a plan view showing a state in which an insulating film is formed on the MR head portion.
FIG. 19 shows X in FIG.₉-X_TenIt is sectional drawing in a line.
FIG. 20 is a diagram for explaining a method of manufacturing an MR head, and is a plan view showing a state in which external terminals are formed.
FIG. 21 shows an X in FIG.₁₁-X₁₂It is sectional drawing in a line.
22 is a diagram for explaining a method of manufacturing an MR head, and is a plan view showing a state in which a number of MR head portions are formed on one surface of a first substrate. FIG.
FIG. 23 is a view for explaining the method of manufacturing the MR head, and is a plan view showing a state in which a number of MR head portions are formed on the other surface of the first substrate.
FIG. 24 It is a figure explaining the manufacturing method of MR head, and is a top view which shows the state by which the 1st board | substrate was cut and it was set as the MR head part row | line | column.
FIG. 25: X in FIG.₁₃-X₁₄It is sectional drawing in a line.
FIG. 26 It is a figure explaining the manufacturing method of MR head, and is a perspective view which shows the state which affixed the 2nd board | substrate and the 3rd board | substrate on the 1st board | substrate cut into MR head part row | line | column.
FIG. 27 is a diagram for explaining a manufacturing method of an MR head, and is a plan view showing a cutting direction when a MR head part row is cut for each MR head part;
FIG. 28 It is a figure explaining the manufacturing method of MR head, and is a perspective view which shows the state which affixed the guard material on the 1st board | substrate cut for every MR head part.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rotating drum apparatus, 2 Fixed drum, 3 Rotating drum, 4 Motor, 5a, 5b Inductive magnetic head, 6a, 6b MR head, 7 Magnetic tape

Claims (5)

In a magnetoresistive effect type magnetic head mounted on a helical scan type magnetic recording / reproducing apparatus using a magnetic tape as a recording medium,
The magnetoresistive effect type magnetic head has two magnetoresistive effect type magnetic head parts in which a thin film magnetoresistive effect element is sandwiched between a pair of soft magnetic bodies via an insulating layer ,
The two magnetoresistive heads have the same azimuth angle inclined at a constant angle with respect to the running direction of the magnetic tape, and are parallel to each other with a predetermined interval in the film thickness direction of the magnetoresistive element. A magnetoresistive head that is integrally formed . 2. The magnetoresistive effect according to claim 1, wherein the magnetoresistive effect element is formed with a length larger than a track pitch of a recording track formed on the magnetic tape and smaller than twice the track pitch. Type magnetic head. In a helical scan type magnetic recording / reproducing apparatus using a magnetic tape as a recording medium ,
A substantially cylindrical rotating drum;
Mounted on the rotary drum, a thin film-like magnetoresistive effect element has two magnetoresistive head portion formed by between a pair of soft magnetic material with an insulating layer, the two magneto-resistive The mold head portion has the same azimuth angle inclined by a certain angle with respect to the traveling direction of the magnetic tape and is integrally formed in parallel with each other at a predetermined interval in the film thickness direction of the magnetoresistive effect element. A first magnetoresistive magnetic head;
Mounted on the rotary drum, a thin film-like magnetoresistive effect element has two magnetoresistive head portion formed by between a pair of soft magnetic material with an insulating layer, the two magneto-resistive The mold head portion has the same azimuth angle inclined by a certain angle with respect to the traveling direction of the magnetic tape and is integrally formed in parallel with each other at a predetermined interval in the film thickness direction of the magnetoresistive effect element. A second magnetoresistive effect type magnetic head,
A magnetic recording / reproducing apparatus for reproducing information signals from the magnetic tape by a non-tracking method . 3. The magnetic recording / reproducing apparatus according to claim 2, wherein the first magnetoresistive head and the second magnetoresistive head have the azimuth angles opposite to each other. 4. The magnetic recording / reproducing apparatus according to claim 3, wherein the magnetoresistive element is formed with a length larger than a track pitch of a recording track formed on the magnetic tape and smaller than twice the track pitch. apparatus.

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