JPH05166152A - Removable hard disk device - Google Patents

Abstract

PURPOSE:To easily control the azimuth deviation of a magnetic head. CONSTITUTION:A cartridge disk 30 which a hard disk 31 is housed in a case 33 is formed to be freely attachable to and detatchable from a head disk main body device 40. The disk 40 is provided with an azimuth control member 44 made of the crystal, etc., and attached to the tip of an oscillating arm 41. Then a needle-shaped head 45 is attached to the tip of the member 44. The member 44 bends in response to an electric signal so that the azimuth angle of the head 45 is adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called removable hard disk device in which a hard disk is removable, and particularly to a hard disk device devised so that the azimuth deviation of a magnetic head can be easily corrected to a normal angle. Is.

[0002]

2. Description of the Related Art Hard disk devices are widely used as external storage devices for computers. In a hard disk device, a disk in which a magnetic material is applied to an aluminum substrate is rotated at high speed (2700 to 3600 rpm), and magnetic recording / reproduction is performed by a flying head. There are the following three methods for classifying this hard disk device according to the mounting state of the disk. (I) A fixed disk system in which the disk is housed in the cavity and fixed to the rotating shaft so that the disk cannot be replaced. (Ii) A disc pack method in which a plurality of discs are stacked and attached to a rotating shaft in the disc pack, and the entire disc pack can be replaced as a unit. (Iii) A cartridge disk system in which one disk is housed in a cartridge case, and the cartridge case can be inserted into and removed from the main body of the hard disk device for replacement.

A hard disk main unit and a cartridge disk of a conventional hard disk device (removable hard disk device) adopting the cartridge disk system will be described with reference to FIG. The cartridge disk 1 is configured such that a hard disk 3 is rotatably housed and supported in a case 2, and a shutter 4 is provided on the rear surface of the case 2. On the other hand, the hard disk main unit 5 has a disk insertion / removal window 6 on the front surface, and is internally provided with a motor, an arm, a magnetic head, a voice coil motor, a shutter opening / closing mechanism, a recording / reproducing circuit, a servo circuit, and the like. ..

When the cartridge disk 1 is mounted in the hard disk main unit 5 through the disk insertion / removal window 6,
The shutter 4 is opened, and the two heads enter the case 2 to perform magnetic recording / reproduction on the upper surface and the lower surface of the hard disk 3.

[0005]

By the way, in the removable hard disk device as shown in FIG. 16, when reproducing one cartridge disk 1 by different hard disk main devices, variations in characteristics of the hard disk main devices and chucking The angle of the head gap with respect to the track may deviate from the normal angle due to an error or a change in environmental conditions. If the angle of the head gap is deviated in this way, azimuth loss occurs, and particularly the high frequency component of the reproduced signal is greatly attenuated and the reproducing characteristic is deteriorated. In addition, when it is attempted to maintain good reproduction characteristics by taking azimuth loss into consideration, the recording frequency must be lowered, and in this case, a new problem that the recording density is lowered occurs. Such a problem is caused by the fact that the cartridge disk 1 can be attached to and detached from the hard disk main body apparatus 5, and such a problem does not occur in a fixed disk type hard disk apparatus.

In view of the above-mentioned conventional technique, it is an object of the present invention to provide a removable hard disk device which can easily correct an azimuth shift.

[0007]

The structure of the present invention which achieves the above-mentioned object is a hard disk main unit for magnetic recording / reproducing by a magnetic head provided on a swinging arm, and a single hard disk rotatable in a case. In a removable hard disk device including a cartridge disk that is housed in a hard disk body and is detachably mounted in the hard disk body device, an azimuth that bends in a direction that changes an azimuth angle of the magnetic head with respect to a track according to an input electric signal. An angle adjusting member is provided on the arm, and a magnetic head is provided at the end of the azimuth angle adjusting member.

[0008]

When the electric signal is sent to the azimuth angle adjusting member, the azimuth angle adjusting member bends according to the electric signal, and the azimuth angle of the head can be adjusted.

[0009]

[First Embodiment] First, a needle-shaped head (MICROFLEXHEAD, US Censtor) provided in the hard disk main unit of the first embodiment.
(Manufactured by the company) will be described with reference to FIG. In the needle head 10 shown in FIG. 1, the head structure 11 is made of aluminum oxide, and the length L1 is 12.7 mm, the length L2 is 0.5 mm, and the thickness (length in the direction perpendicular to the paper surface). Is 0.5 mm and is very thin and needle-shaped. A main magnetic pole 12, a yoke 13, a stud portion 14, and an auxiliary magnetic pole 15 are formed in the needle-shaped head 10 with a high magnetic permeability material. Further, a coil 16 that surrounds the yoke 13 in a spiral shape is formed, and the coil 16 is connected via the lead conductor 17 to the bonding pad 1.
8 is electrically connected.

Needle-like head 10 having such a structure
Is small and lightweight, and since the area of the portion that comes into contact with the recording medium is small, recording and playback can be performed while it is in contact with the hard disk. Of course, the contact recording does not scratch the needle head 10 or the hard disk. Further, the needle-shaped head 10 has a good spring characteristic that it does not break even if it is bent with a large curvature, and immediately returns to the linear state shown in FIG. 1 when the bending force disappears.

FIG. 2 schematically shows the state of the magnetic path when recording / reproducing is performed by the needle head 10. As shown in FIG. 2, in the perpendicular recording hard disk 20, the substrate 21
A soft magnetic layer 22 is formed on the perpendicular magnetic layer 23.
Are formed. The main magnetic pole 12 of the needle-shaped head 10 performs magnetic recording / reproduction while being in contact with the perpendicular magnetic layer 23. That is, as shown by the dotted line in FIG. 2, the main magnetic pole 12 → the perpendicular magnetic layer 23 → the soft magnetic layer 22 → the perpendicular magnetic layer 23 → the auxiliary magnetic pole 15
A magnetic path is formed along the path of the stud portion 14, the yoke 13 and the main magnetic pole 12. Thus, the portion of the perpendicularly magnetized layer 23 that is in contact with the main magnetic pole 12 is vertically magnetized, and perpendicular magnetic recording is performed, and reproduction is possible.

By using the needle-shaped head 10, recording and reproduction can be performed in contact with the recording medium, so that the advantage of perpendicular magnetic recording that high density recording can be achieved can be fully brought out.
Since various conventionally developed perpendicular magnetic recording heads are large and heavy, they cannot be brought into contact with the magnetic layer and must be used in a floating state. Therefore, perpendicular magnetization was possible but high density recording was not sufficiently possible. That is, high density recording using perpendicular magnetic recording became practical only after using the needle head.

Next, the hard disk device of the embodiment will be described with reference to FIG. FIG. 3 shows a state in which the cartridge disk 30 is inserted into the hard disk body device 40, and shows only the main components.

The cartridge disk 30 has substantially the same structure as the cartridge disk 1 having the hard disk 3 for horizontal magnetic recording shown in FIG. 16, but the hard disk 31 is of a type capable of perpendicular magnetic recording. There is. The hard disk 31 has a metal hub 32 at the center and is rotatably housed in a plastic case 33. A shutter (not shown) is provided on the rear surface (upper surface in the drawing) of the case 33.
The shutter is opened by an opening / closing mechanism (not shown) of the hard disk body device 40 when the cartridge disk 30 is inserted into the hard disk body device 40, and closed when taken out of the hard disk body device 40.

A plurality of tracks are concentrically formed on the hard disk 31 and are divided into a plurality (about 20 to 40) of sectors S1 to SN along the circumferential direction as shown in FIG.

Next, recording modes of various head adjusting signals will be described with reference to FIGS. In both figures, the tracks are shown as straight lines for the sake of convenience. As shown in both figures, each track T (represented by T representing T1, T2, T3, T4 ...) Is divided into a plurality of sectors S (represented by S representing S1, S2. Each sector S is divided into a head adjustment signal area H and a user signal area U.

A sector start signal K is recorded at the beginning of each sector S, that is, at the beginning of the head adjustment signal area H. Following the sector start signal K, a tracking signal Tr is recorded.
Is recorded. The signals K and Tr are also recorded in the conventional hard disk. In this embodiment, further, the tracking signal Tr is followed by the azimuth adjustment signals A1 and A2.
Is recorded. Although the absolute values of the azimuth angles of both azimuth adjustment signals A1 and A2 are the same, the directions of the azimuth angles are opposite. In the embodiment of FIG. 5, the widths of the azimuth adjustment signals A1 and A2 are narrower than the track width and are recorded in all sectors S of all tracks T. On the other hand, in the embodiment of FIG. 6, the widths of the azimuth adjustment signals A1, A2 are wider than the track width, and are recorded in the odd-numbered sectors S1, ... On the odd-numbered tracks T1, T3. It is recorded in S2 ... The signals K, Tr, and A for head adjustment described above are the cartridge disk 30.
In the manufacturing process of, accurate recording (perpendicular magnetic recording) is performed by the format device.

In the embodiment of FIG. 6, the azimuth adjustment signals A1 and A2 are recorded in the odd sectors of the odd tracks and the even sectors of the even tracks, but they may be recorded in the even sectors of the odd tracks and the odd sectors of the even tracks. You can

On the other hand, in the user signal area U, a signal used by the user is modulated by the NRZ (non-return-to-zero) method or the like and perpendicularly magnetically recorded.

Returning to FIG. 3, the hard disk main unit 40 will be described. The arm 41 is pivotally supported by a bearing 42, and is swung about the bearing 42 by the driving of the voice coil motor 43. An azimuth angle adjusting member 44 is provided at the tip of the arm 41, and a needle head 45 is provided at the tip of the azimuth angle adjusting member 44. The needle head 45 has the same structure as that shown in FIG. 1, and performs perpendicular magnetic recording / reproduction on the upper surface of the hard disk 31. It should be noted that although the same constituent members as the members 41, 42, 44 and 45 are provided for perpendicular magnetic recording / reproduction on the lower surface of the hard disk 31, they are not shown. The voice coil motor 43 includes an arm 41 that swings on the upper surface side of the hard disk 31 and an arm that swings on the lower surface side (not shown).
Are independently driven.

The azimuth angle adjusting member 44 has a function of adjusting the orientation of the needle-shaped head 45 with respect to the arm 41 by bending and making the main magnetic pole of the needle-shaped head 45 normal to the track to eliminate azimuth loss. is doing. The configuration of the azimuth angle adjusting member 44 is as shown in FIGS.
The one shown in is adopted.

In the azimuth angle adjusting member 44 shown in FIG.
The crystal plate 50 is provided with a Y-shaped slit 51, two electrodes 52 are provided on the front surface, and two electrodes 52 are provided on the back surface so as to face the front surface. Then, for example, as indicated by the symbols of the directions of the electric fields in the figure, a voltage is applied to the front and back electrodes 52 on the right side to generate an electric field from the back to the front on the paper surface, and the front and back electrodes 52 on the left side are generated. When a voltage is applied to generate an electric field from the front side to the back side of the paper surface, the right side of the crystal plate 50 extends and the left side contracts. In this way, when the crystal plate 50 bends to the left, the orientation of the needle head 45 changes and the azimuth angle can be adjusted. When the direction of the electric field is reversed to that described above, the crystal plate 50 bends to the right, and the azimuth angle can be adjusted in the direction opposite to the direction described above. The adjustment amount of the azimuth angle can be controlled by adjusting the applied voltage.

The azimuth angle adjusting member 44 shown in FIG. 8 is the same as that shown in FIG. 7 except that the slit 51a has a rectangular shape.

In the azimuth angle adjusting member 44 shown in FIG. 9,
Piezoelectric elements 56 that are stacked are provided on the left and right sides of a main body 55 having an I-shaped flexibility. And the left and right piezoelectric elements 5
It is possible to adjust the azimuth angle of the needle-shaped head 45 by bending the main body 55 by adjusting the voltage characteristics applied to 6 in reverse and expanding and contracting the piezoelectric element 56.

In the azimuth angle adjusting member 44 shown in FIG. 10, the piezoelectric element 56 is provided only on the arm 41 side so that the amount of deflection of the needle-shaped head 45 increases as the piezoelectric element 56 expands and contracts.

In the azimuth angle adjusting member 44 shown in FIG. 11, the central portion of the needle-shaped head 45 is sandwiched and supported by the claw portion 60a of the body 60, and a stack is formed between the base end portion of the needle-shaped head 45 and the body 60. The piezoelectric element 61 is provided. Then, the azimuth angle can be adjusted by shaking the needle head 45 by expanding and contracting the piezoelectric element 61 by adjusting so that the voltage characteristics applied to the left and right piezoelectric elements 61 are reversed.

In the azimuth angle adjusting member 44 shown in FIG. 12, the needle-shaped head 4 is composed of the piezoelectric element 61 and the piezoelectric element 62.
We support 5 in total. Then, the azimuth angle of the needle head 45 can be adjusted by adjusting the voltage characteristics applied to the piezoelectric elements 61 and 62.

FIG. 13 is a block diagram showing a signal reproducing system and a head servo system of the hard disk main unit 40 shown in FIG. The needle head 45 perpendicularly magnetically records the user data D in the user signal area U of the track T during recording. At the time of reproduction, the needle-shaped head 45 has the sector start signal K, the tracking signal Tr, and the azimuth adjustment signal A which are perpendicularly magnetically recorded in the head adjustment signal area H of the track T.
1, A2 is reproduced, and user data D is reproduced. Reproduced signals (data) D, K, Tr, A1,
A2 is amplified by the preamplifier 70 and then sent to the data punching circuit 71.

The data punching circuit 71 extracts the tracking signal Tr and the azimuth adjustment signals A1 and A2 in timing, sends the signals Tr, A1 and A2 to the A / D conversion circuit 75, and at the same time, the user data D and the sector start. The signal K is sent to the data separator 72. The timing of extracting the tracking signal Tr and the azimuth adjustment signals A1 and A2 is determined based on the timing signal CLK output from the timing generation circuit 73.

The data separator 72 is the user data D
And the sector start signal K are separated. The user data D is demodulated by the signal demodulation circuit 74 and output as a reproduction signal. The sector start signal K is sent to the timing generation circuit 73, and the timing generation circuit 73 uses the timing signal CLK as a reference time point when the sector start signal K is input.
To occur.

The A / D conversion circuit 75 converts the amplitudes of the extracted tracking signal Tr and azimuth adjustment signals A1 and A2 into digital signals. The logical operation circuit 76 obtains the tracking deviation amount TrZ of the needle head 45 from the magnitude of the tracking signal Tr, and calculates the azimuth adjustment signal A1,
Azimuth deviation amount AZ of the needle head 45 from the size of A2
Ask for.

The tracking shift amount TrZ is the magnitude of the reproduction signal of the tracking signal Tr located on the right side with respect to the traveling direction of the needle head 45 and the magnitude of the reproduction signal of the tracking signal Tr located on the left side with respect to the traveling direction. It can be calculated from the difference. From this difference, the tracking deviation amount T
rZ is calculated. When there is no tracking shift, the tracking shift amount TrZ becomes zero.

The azimuth shift amount AZ is determined by the azimuth signal A1.
It can be obtained by comparing the magnitude of the reproduced signal of 1 and the magnitude of the reproduced signal of the azimuth signal A2. A1>
When A2, the needle head 45 is tilted in the direction of the azimuth signal A1, and when A1 <A2, the needle head 4 is tilted.
It can be determined that 5 is tilted in the direction of the azimuth signal A2. In the example of FIG. 6, there is a sector in which the azimuth signals A1 and A2 are not recorded. However, since the values of the azimuth signals A1 and A2 are minimal in that sector, the azimuth deviation is not determined and the azimuth signals A1 and A2 are not determined. Azimuth shift is determined only in the sector where A2 is recorded.

If there is an azimuth shift, the following equation
Jimass loss L_aOccurs. However, L _aIs the azimuth loss,
ω is the track width, θ is the azimuth angle, and λ is the recording wavelength.

[0035]

[Equation 1]

When there is an azimuth shift or a tracking shift, the head position is servo-controlled so as to eliminate the shift as described below. However, since the azimuth angle and the track position interfere with each other, the logical operation circuit 76 The azimuth shift amount AZ and the tracking shift amount TrZ are corrected and obtained so as to cancel the mutual interference when the servo control is performed. The details will be described later.

The servo control circuit 77 controls the azimuth deviation amount A
The azimuth servo signal AS that makes Z zero is output, and the tracking servo signal TrS that makes the tracking shift amount TrZ zero is output. Azimuth servo signal AS
As a result, the azimuth angle adjusting member 44 (FIG. 3) operates and the azimuth angle of the needle head 45 becomes zero. Further, the tracking servo signal TrS activates the voice coil motor 43 (FIG. 3) to swing the arm 41 so that the needle-like head 45 is positioned on the track without track deviation.

Mutual interference between the azimuth shift correction and the tracking shift correction will be described. As shown in an exaggerated schematic view in FIG. 14, when the needle-shaped head 45 is on the track center t but there is an azimuth shift (solid line state),
If only the azimuth adjustment is performed and the needle-shaped head 45 is moved in the direction shown by the dotted line, a track shift will occur. Also in FIG.
As exaggeratedly and schematically shown, when the needle-shaped head 45 has no azimuth displacement but is displaced from the track center t (solid line state), if only the track adjustment is performed and the arm 41 is moved to the position shown by the dotted line. In the needle head 45, the azimuth shift occurs as shown by the dotted line.

In consideration of the above situation in advance, the logical operation circuit 76 outputs the azimuth shift amount AZ and the tracking shift amount TrZ so as to cancel the mutual interference. That is, even when only one of the azimuth shift and the tracking shift is present, the azimuth shift amount AZ and the tracking shift amount TrZ corrected so as to cancel the mutual interference are output.

In this embodiment, since the azimuth adjustment signals A1 and A2 having the same absolute value but different directions are recorded in the hard disk 31 in advance, the azimuth adjustment signals A1 and A1 are recorded.
By reproducing A2 and comparing the magnitudes of the reproduced signals, the azimuth shift of the needle head 45 can be easily detected. Since the azimuth angle adjusting member 44 can be flexed according to an electric signal to adjust the azimuth angle of the needle-shaped head 45, the azimuth deviation can be corrected and the needle-shaped head 45 can be set to the regular azimuth angle. .. Therefore, the cartridge disk 30 is replaced by the hard disk main unit 4
Even if there is a chucking deviation or a change in environmental conditions when mounted on 0, azimuth adjustment can be performed easily and quickly, and magnetic recording / reproduction can be performed without azimuth deviation.

Further, in this embodiment, the cartridge disk 3 is used.
Since 0 is a removable hard disk that can be attached to and detached from the hard disk main unit 40, a plurality of cartridge disks 30 can be magnetically recorded / reproduced by one hard disk unit 40, which is convenient. Moreover, since the needle-shaped head 45 is used as the magnetic head, the advantage of perpendicular magnetic recording that high density recording can be achieved can be fully brought out.

[0042]

According to the present invention, the azimuth angle adjusting member bends and the azimuth angle of the magnetic head changes only by sending an electric signal to the azimuth angle adjusting member. Therefore, the azimuth angle of the head can be easily made a normal angle. be able to.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a needle-shaped head used in an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a state of a magnetic path when a needle-shaped head is used.

FIG. 3 is a configuration diagram showing a removable hard disk device of an embodiment.

FIG. 4 is a conceptual diagram showing sectors of a hard disk.

FIG. 5 is a conceptual diagram showing a recording mode of a head adjustment signal.

FIG. 6 is a conceptual diagram showing a recording mode of a head adjustment signal.

FIG. 7 is a configuration diagram showing an azimuth angle adjusting member.

FIG. 8 is a configuration diagram showing an azimuth angle adjusting member.

FIG. 9 is a configuration diagram showing an azimuth angle adjusting member.

FIG. 10 is a configuration diagram showing an azimuth angle adjusting member.

FIG. 11 is a configuration diagram showing an azimuth angle adjusting member.

FIG. 12 is a configuration diagram showing an azimuth angle adjusting member.

FIG. 13 is a block diagram showing a signal reproduction system and a head servo system of the hard disk device of the embodiment.

FIG. 14 is an explanatory diagram showing mutual interference between tracking control and azimuth control.

FIG. 15 is an explanatory diagram showing mutual interference between tracking control and azimuth control.

FIG. 16 is a configuration diagram showing a conventional removable hard disk device.

[Explanation of symbols]

 1 Cartridge Disk 2 Case 3 Hard Disk 4 Shutter 5 Hard Disk Main Unit 6 Disk Insertion / Ejection Window 10 Needle Head 11 Head Structure 12 Main Magnetic Pole 13 Yoke 14 Stud 15 Auxiliary Magnetic Pole 16 Coil 17 Lead Conductor 18 Bonding Pad 20 Hard Disk 21 Substrate 22 Soft magnetic layer 23 Perpendicular magnetization layer 30 Cartridge disk 31 Hard disk 32 Metal hub 33 Case 40 Hard disk main body device 41 Arm 42 Bearing 43 Voice coil motor 44 Azimuth angle adjusting member 45 Needle head 50 Crystal body 51, 51a Slit 52 Electrode 55 Main body 56 Piezoelectric Element 60 Main body 60a Claw portion 61, 62 Piezoelectric element 70 Preamplifier 71 Data punching circuit 72 Data separator 73 Timing generation circuit 74 Signal recovery Circuit 75 A / D conversion circuit 76 Logical operation circuit 77 Servo control circuit K Sector start signal Tr Tracking signal A1, A2 Azimuth adjustment signal T Track S Sector D User data H Head adjustment signal area U User signal area AZ Azimuth deviation amount TrZ Tracking deviation amount AS Azimuth servo signal TrS Tracking servo signal

Claims (3)

[Claims] 1. A hard disk main unit for performing magnetic recording / reproduction by a magnetic head provided on an oscillating arm, and 1.
In a removable hard disk device consisting of a hard disk body, which is rotatably housed in a case and is detachably mounted in a hard disk main unit, in accordance with an input electric signal, an azimuth angle of the magnetic head with respect to a track. A removable hard disk drive characterized in that the arm is provided with an azimuth angle adjusting member that bends in a direction that changes the angle, and a magnetic head is provided in front of the azimuth angle adjusting member. 2. The removable hard disk device according to claim 1, wherein the azimuth angle adjusting member includes a single-crystal piezoelectric body and an electrode provided on the piezoelectric body and acting an electric field. 3. The removable hard disk device according to claim 1, wherein the azimuth angle adjusting member includes a flexible main body and stacked piezoelectric elements.