KR20070075061A - Hard disk drive - Google Patents

Abstract

An HDD(Hard Disk Drive) is provided to considerably reduce TPI(Track Per Inch) loss and improve the recording density of the HDD by reducing a skew angle formed by a magnetic head and a track when data are recording and reproduced on and from a disk. A plurality of tracks of a concentric shape is formed in at least one disk. A plurality of magnetic heads(h) records or reproduces data in and from the disk. An actuator has a slider, to which a plurality of the magnetic heads(h) is mutually combined at inter-different angle for a central axis line of a longitudinal direction, and moves the magnetic heads(h) to the track on the disk. A controller(60) controls the movement of the actuator.

Description

Hard Disk Drive {Hard Disk Drive}

1 is a graph of tracks per inch (TPI) according to the skew angle of a hard disk drive according to an exemplary embodiment.

2 is a plan view of a hard disk drive according to an embodiment of the present invention.

3 is a perspective view of a slider of the hard disk drive of FIG. 2.

FIG. 4 is a bottom view of region 'A' of FIG. 3.

FIG. 5 is a schematic block diagram of a driving circuit of the hard disk drive of FIG. 2.

FIG. 6 is a diagram illustrating a state where a magnetic head is located in a disk inner track of the hard disk drive of FIG. 2.

FIG. 7 is a diagram illustrating a state in which a magnetic head is positioned in a disk intermediate track of the hard disk drive of FIG. 2.

FIG. 8 is a diagram illustrating a state in which a magnetic head is positioned in a disk outer track of the hard disk drive of FIG. 2.

9 is a graph of tracks per inch (TPI) according to the skew angle of the hard disk drive of FIG. 2.

          * Explanation of symbols for the main parts of the drawings

1: Hard Disk Drive 10: Disk

30: spindle motor 40: actuator

60: controller 70: voice coil motor (VCM)

h: magnetic head s: slider

The present invention relates to a hard disk drive, and more particularly, to a hard disk drive having a plurality of magnetic heads coupled at different angles with respect to the center axis of the slider.

A hard disk drive is a storage device that consists of electronic devices and mechanical devices that converts digital electronic pulses into a more permanent magnetic field to record and play back data. It can access large amounts of data at high speed. It is widely used as an auxiliary storage device of a computer system because it can be used.

These hard disk drives have recently been getting higher capacity with high track per inch (TPI) and high bits per inch (BPI) implementations, and their applications are expanding. In fact, a small hard disk drive with a diameter of 0.85 inches and a size similar to a 100 won coin has been developed and will be used in future mobile phones.

Magnetic head, a key component of the hard disk drive used as a secondary memory of a computer, is a magneto-resistive head (MR head, Magneto Resistive) for ultra-high-capacity ultra high density from various types of heads (thin head, MIG head, etc.). head) has been developing. The magnetoresistive head reads and writes data on the disk surface or reproduces the recorded data by reading and writing operations due to electrical and magnetic characteristics. Initially, the magnetic head was an inductive type that reads and writes with one pole and a gap, but recently, reads and writes are performed by each pole and gap. to be. That is, the magnetoresistive head which reads as a read sensor and writes as a write sensor is used.

An insulation layer and a shared pole are interposed between the write sensor and the read sensor to maintain a constant distance. At this time, the write sensor and the read sensor have a shape in which the center thereof is located on the same straight line, and the write track width is larger than the read track width.

However, in the conventional hard disk drive, since the read sensor and the write sensor are provided separately, there is an advantage that can be individually optimized in the channel of the drive according to their characteristics, but the magnetic head In terms of the read and write sensors are provided separately, the offset (offset) occurs on the track (off track) occurs, and when the magnetic head is moved to the inner track or outer track, it is made in the circumferential direction on the disk A skew angle, which is a relative angle between the track and the magnetic head, is generated.

Therefore, in the inner track or outer track having a large skew angle, an adjacent track erasing (ATE, Adjacent Track Erasure) phenomenon may occur when the data of the adjacent track is deleted when the write sensor operates. In the track, the width of the track is comparable to that of the intermediate track. This in turn lowers the number of tracks per inch (TPI), leading to capacity loss.

That is, in the conventional hard disk drive, in order to prevent an adjacent track erasing (ATE) phenomenon or the like that may occur due to an increase in the skew angle in the inner track and the outer track, it is shown in FIG. As can be seen, there is a problem in that the number of tracks per inch (TPI) cannot be increased in the inner track or the outer track so that the maximum capacity of the hard disk drive cannot be expected.

Accordingly, it is an object of the present invention to reduce the skew angle between the magnetic head and the track at the time of recording and reproducing data on the disk, thus reducing the track per inch (TPI) loss. It is to provide a hard disk drive that can be significantly reduced to improve the recording density of the hard disk drive.

The object is, according to the present invention, at least one disk provided with a plurality of tracks substantially concentric in shape; A plurality of magnetic heads for recording or reproducing data on the disc; An actuator having a plurality of magnetic heads coupled at different angles with respect to a longitudinal center axis, the actuator moving the magnetic head to a track on the disk; And it is achieved by a hard disk drive comprising a controller for controlling the movement of the actuator.

At this time, when the plurality of magnetic heads are disposed on the disk for recording and reproducing data on the disk, the skew angle of one of the magnetic heads with respect to any one of the inner track and the outer track of the disk remains. Preferably, the plurality of magnetic heads are coupled to the slider such that the magnetic heads are smaller than the skew angle for the corresponding track.

The plurality of magnetic heads may be coupled to the slider at equal angle intervals on a predetermined arc of the slider in a rotational radial direction of the actuator.

The plurality of magnetic heads may include one magnetic head disposed substantially parallel to a center axis of the slider, and two to five degrees in both directions with respect to the central axis of the one magnetic head on both sides of the one magnetic head. It may be composed of two magnetic heads spaced at a predetermined distance apart from each other.

The controller further includes a magnetic head having the smallest skew angle on a corresponding track of the disk among the plurality of magnetic heads when the plurality of magnetic heads are disposed on the disk when recording and playing data on the disk. It is preferable to operate.

At this time, the controller controls the movement of the actuator so that the magnetic head having the smallest skew angle for each of the inner track, the middle track, and the outer track of the disc is located on the track when data is recorded and reproduced.

The controller may further include a magnetic head having the minimum skew angle for each of the inner track, the middle track, and the outer track of the disk, when one of the plurality of magnetic heads does not operate. The movement of the actuator can be controlled to be located on the track.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is a plan view of a hard disk drive according to an embodiment of the present invention, FIG. 3 is a perspective view of a slider of the hard disk drive of FIG. 2, and FIG. 4 is a bottom view of region 'A' of FIG. 3. 5 is a schematic block diagram of a driving circuit of the hard disk drive of FIG. 2, and FIGS. 6 to 8 are views illustrating a state in which a magnetic head is positioned in a disc inner track, an intermediate track, and an outer track of the hard disk drive. to be.

As shown in these figures, the hard disk drive 1 according to an embodiment of the present invention includes a disk 10 for recording and storing data, and a data recorded or recorded on the disk 10. Three magnetic heads (hi, hm, ho) for reproducing data, and three magnetic heads (hi, hm, ho) are mounted at different angles with respect to the longitudinal center axis. Most circuits including an actuator 40 for moving the magnetic head h to the target track t on the disk 10, a controller 60 for controlling the movement of the actuator 40, and a controller 60 A printed circuit board assembly (PCBA, Printed Circuit Board Assembly) for controlling the above-mentioned parts by having a printed circuit board (PCB) on which the parts are mounted, and a base 90 on which these components are assembled. do.

One or more disks 10 are installed to be rotated by the spindle motor 30 at predetermined intervals from each other, and a plurality of concentric circular tracks t are provided. In the track t, the servo sector and the data sector are alternately located. The servosector is a track seeking in which the magnetic head h moves the track t to reach the target track and the final target track is reached so that the magnetic head h is moved to the centerline of the track t. It is for servo control such as track following for positioning on the centerline, and the data sector is for recording user data. Track search and track following in the hard disk drive 1 are performed by using a servo sector previously recorded in the track t by a servo writer.

Three magnetic heads (hi, hm, ho) are mounted on the slider (s) at the end of the actuator arm (41) rotatably coupled to the rotational shaft (47) for recording or reproducing data on the disk (10). do. In addition, the three magnetic heads (hi, hm, ho) are coupled at different angles with respect to the central axis of the slider (s), where one magnetic head (h) of the inner peripheral track (ID) of the disk (10) 3) so that the skew angle for the outer track OD (see FIG. 8) is less than the skew angle for the corresponding track t of the remaining magnetic heads h. Heads hi, hm and ho are coupled to slider s.

In the 3.5-inch hard disk drive 1, the actuator 40 moves on the disk 10 with a rotation radius of about 30 degrees about the rotation shaft 47. That is, the actuator 40 rotates with a rotation radius of about 15 degrees in the inner track direction and about 15 degrees in the outer track direction around the intermediate track. Therefore, the magnetic head hi for the inner track and the magnetic head ho for the outer track with respect to the magnetic head hm for the intermediate track are arranged at intervals of approximately 7.5 degrees. The skew angle for the track can be minimized on average.

This will be described in detail with reference to FIG. 4 as follows.

The three magnetic heads hi, hm, and ho are arranged in such a manner that their centers are located on the same straight line in the width direction. Each of the magnetic heads hi, hm, and ho includes a write sensor ws and a read sensor rs, and an insulation layer between the write sensor ws and the read sensor rs. Keep a certain distance through the. The three magnetic heads (hi, hm, ho) have a magnetic head (hi) for the inner track and a magnetic head (ho) for the outer track with respect to the magnetic head (hm) for the intermediate track, respectively. ) Is coupled to the slider (s). Therefore, the magnetic head having the smallest skew angle for each of the inner track ID, the middle track MD and the outer track OD of the disc 11 by the controller 60 when recording and reproducing data. (h) is selected and the actuator 40 moves the magnetic head h onto the disk 10 based on this.

The actuator 40 is installed on the actuator arm 41 rotatably coupled to the pivot shaft 47, the slider s on which the magnetic head h is mounted, and the actuator arm 41, thereby providing the slider s. A suspension 45 for elastically biasing toward the surface of the disk 10 and a voice coil motor 70 for rotating the actuator arm 41 about the pivot shaft 47 are provided.

Here, the voice coil motor 70 has a voice coil 73 wound around the bobbin portion 71, and a magnet 75 for generating a magnetic force line. As a result, electromagnetic force is generated by the interaction between the magnetic force line generated by the magnet 75 and the current flowing through the voice coil 73, thereby causing the actuator 40 to rotate according to Fleming's left hand law. The controller 60 controls the electromagnetic force to move the magnetic head h to the desired position of the disk 10. The actuator arm 41 rotates on the disk 10 about the rotation shaft 47 with a rotation radius of about 30 degrees to position the head h on the target track t.

The controller 60 is provided in a printed circuit board assembly (not shown). The controller 60 is connected to the memory 65 to exchange commands and data and to generate a servo sector number and a track address from the data read from the magnetic head h so that the magnetic head h is positioned on the disk 10. The position on the track t to be determined is determined.

Referring to FIG. 5, the servo information read from the magnetic head h passes through the read preamplifier & write driver 61 and the read / write (R / W) channel 62. This servo information is interpreted by the controller 60 so that the controller 60 generates a servo sector number and track address. Based on the generated servo sector number and the track address, the controller 60 controls the magnetic head (H) on a track t in which the magnetic head h is located on the disk 10 and on any servo track in a specific track t. After calculating whether h) is located, a control signal is applied to the VCM driver 67 to supply a drive current to the voice coil 73 to move the magnetic head h to the target track t.

At this time, the controller 60 selects any one of the three magnetic heads (hi, hm, ho) most suitable magnetic head (h) to move to the target track (t) by skew angle with respect to the track (t) Make sure the skew angle is minimal.

Referring to the operation of the hard disk drive according to an embodiment of the present invention by such a configuration as follows.

The controller 60 of the hard disk drive 1 has a magnetic head h having the smallest skew angle at a specific track t of the disk 10 of the three magnetic heads hi, hm and ho. Activate In addition, the controller 60 positions three magnetic heads hi, hm and ho so as to be close to a specific track t for recording or reading data, and among the three magnetic heads hi, hm and ho. The movement of the actuator 40 is controlled so that the magnetic head h having the smallest skew angle for each track t is located on the track t. This will be described in more detail as follows.

The controller 60 determines the position on the track t where the magnetic head h should be located. That is, if there is a request for data recording or reading from the host computer (not shown), the controller 60 determines the track t at which the data is to be recorded or read.

When the position of the track t at which the magnetic head h is to be located is located at the inner track ID of the disk 10, the controller 60 minimizes the skew angle at the inner track ID. The magnetic head hi may be selected to generate a position control signal such that the magnetic head hi is located on the track t.

The position control signal generated by the controller 60 is input to the VCM driver 67, and the VCM driver 67 drives the voice coil motor 70 to move the actuator arm 41 around the pivot shaft 47. To be rotated. When the actuator arm 41 is rotated, the skew angle is minimized in the inner track ID among the three magnetic heads hi, hm, and ho positioned at the ends of the sliders s provided on the actuator arm 41. The magnetic head hi can be located on the target track t.

In addition, when the target track t specified by the controller 60 is the middle track MD of the disc 10, the magnetic head may minimize the skew angle in the middle track MD region. hm) is selected, and in the case of the outer track OD, a magnetic head ho whose skew angle can be minimized in the outer track OD is selected and positioned on the target track t.

On the other hand, the controller 60 controls the movement of the actuator 40 when any one of the three magnetic heads (hi, hm, ho) does not operate, the track t is intended for the magnetic head (h) operating normally The magnetic head (h) having a minimum skew angle with respect to the desired track (t) of the magnetic head (h) in the normal operation of the actuator (h) is also located in the track The movement of 40 can be controlled.

FIG. 9 is a graph of tracks per inch (TPI) according to the skew angle of the hard disk drive of FIG. 2. According to the present invention, tracks per inch (TPI) over the inner track, the middle track, and the outer track of the disk 10 are shown. The hard disk drive 1 which exhibits the characteristic of the number of tracks per inch (TPI) graph B close to the ideal graph A, which is represented by the same, can be implemented. The closer to the ideal graph (A), the higher the recording density can be and the capacity of the hard disk drive 1 can be increased. According to the hard disk drive 1 according to an embodiment of the present invention, the number of tracks per inch ( This means that you can expect maximum hard disk drive capacity by minimizing TPI) losses.

In the above-described embodiment, the case of three magnetic heads has been described above. However, the number of magnetic heads is not limited thereto, and may be two or four or more as necessary.

As described above, the present invention is not limited to the described embodiments, and various modifications and changes can be made without departing from the spirit and scope of the present invention, which will be apparent to those skilled in the art. Therefore, such modifications or variations will have to be belong to the claims of the present invention.

As described above, according to the present invention, the skew angle formed by the magnetic head and the track during recording and reproducing of data on the disk can be reduced compared to the prior art, so that the number of track per inch (TPI) is lost. Can be significantly reduced than before, and the recording density of the hard disk drive can be improved.

Claims (7)

At least one disk provided with a plurality of tracks substantially concentric in shape; A plurality of magnetic heads for recording or reproducing data on the disc; An actuator having a plurality of magnetic heads coupled at different angles with respect to a longitudinal center axis, the actuator moving the magnetic head to a track on the disk; And And a controller for controlling movement of the actuator. The method of claim 1, Skew angle with respect to any one of the inner and outer tracks of the disk of one magnetic head when the plurality of magnetic heads are disposed on the disk to record and reproduce data on the disk. And the plurality of magnetic heads are coupled to the slider such that is smaller than the skew angle for the corresponding track of the remaining magnetic heads. The method of claim 2, And the plurality of magnetic heads are coupled to the slider at equal angle intervals on a predetermined arc of the slider in the radial direction of rotation of the actuator. The method of claim 3, The plurality of magnetic heads may include one magnetic head disposed substantially parallel to a center axis of the slider, and two to five degrees in both directions with respect to the central axis of the one magnetic head on both sides of the one magnetic head. Hard disk drive comprising two magnetic heads spaced at a predetermined distance apart. The method according to claim 3 or 4, The controller operates a magnetic head having the smallest skew angle on a corresponding track of the disk among the plurality of magnetic heads when the plurality of magnetic heads are disposed on the disk when recording and playing data on the disk. Hard disk drive, characterized in that. The method of claim 5, The controller may control the movement of the actuator such that the magnetic head having the smallest skew angle is positioned on the track for each of the inner track, the middle track, and the outer track of the disk. drive. The method of claim 6, The controller may be configured such that, when one of the plurality of magnetic heads does not operate, the magnetic head having the smallest skew angle for each inner track, intermediate track and outer track of the disk among the two magnetic heads operated is the track. And controlling the movement of the actuator to be located in the hard disk drive.

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