KR0163713B1 - Magnetic head core of a magnetic recording and reproducing apparatus - Google Patents

Abstract

1. Fields to which the invention described in the claims belong

The present invention relates to a head core in a magnetic recording / reproducing apparatus, and more particularly to a magnetic head core having different mechanical skew angles of the head core and the media and an angle in the magnetization direction by the actual head core.

2. The technical problem to be solved by the invention

Provides a head core that can solve problems such as position control, vibration characteristics, and signal gain reduction as the actual track width (Wr) of the magnet in the orientation direction of the media and the radial direction of each position on the media is changed.

3. Summary of Solution to Invention

The gap surface of the head core has a head slide and an inclination angle (β), but the shape skew angle and the actual magnetization direction angle of the head slide are different so that recording / playback is different depending on the high capacity of the hard disk and the decrease of the track pitch according to the high density. We are trying to solve the gain loss of the time signal.

4. Important uses of the invention

Magnetic headcore

Description

Magnetic head core in magnetic recording / playback apparatus

1 is a diagram for explaining a head position and skew angle relationship on a media.

2 is a diagram for explaining a radial track width at a specific skew angle.

3 is a diagram showing a change in radial track width in the media outer and inner circumferences.

4 is a view showing a gap surface of a conventional head core.

5 is a view for explaining an example of the head core to which the inclination angle of the gap surface according to the present invention.

6 is a view showing a change in the radial track width after applying the gap surface inclination angle according to the present invention.

7 is a calculation example of the skew angle at the outer diameter OD and the inner diameter ID according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head core in a magnetic recording / reproducing apparatus, and more particularly to a magnetic head core having different mechanical skew angles of the head core and the media and an angle in the magnetization direction by the actual head core.

In general, in the magnetic recording / reproducing apparatus, the gap of the head core coincides with the moving direction of the magnetized media, which is intended to increase the efficiency of the head core by minimizing magnetic flux leakage between the head core and the media. This can be seen in detail in FIG. 4, which will be understood in detail in US Pat. No. 5,233,492 to Iwata on 3 August 1993.

However, due to the limitation of the size of the device, in the hard disk using the rotary actuator, as shown in FIG. 1, the advancing direction of the media 100, that is, the tangential direction 102 and the display direction of the surface of the head core 103 ( At 104, a specific inclination angle 105 (a1, a2) is obtained. When the inclination angle 105 is not considered, the height of the head is increased as the outer circumference 107 portion of the media 100 is increased. This phenomenon can reduce the height of the head rises excessively generated by adjusting the position of the actuator to change the range of the inclination angle 105. Conventionally, as shown in FIG. 4, the axial direction 417 of the head slide and the gap surface 406 are formed to be perpendicular. In general, the magnetization material on the media 100 of FIG. 1 has the orientation of magnetization, that is, orientation, and the higher the efficiency of recording / reproducing as the orientation of the magnetic material and the magnetic flux direction of the head core 103 coincide. However, in the structure in which the axial direction 417 and the gap surface 406 of the slide are vertical as in the case of FIG. 4, when the media are already magnetized in one specific direction after DC-erasure, When rewriting in the direction of maintaining the angle, there was a problem that the efficiency is lowered due to the influence of residual magnetic flux. As shown in FIG. 1, the skew angle 105 is greatly changed according to the position on the media 100. Accordingly, the angle formed between the magnetization direction 106 and the advancing direction of the media 100 is also greatly changed. The recording / reproducing efficiency changes depending on the position. In addition, the failure rate of the seek according to the position control error of the actuator and the degree of change of the off track during the track tracking are shown in FIG. 2 and FIG. 3, in the outer periphery 107 and the inner periphery 108 on the media 100. The vibration displacement degree at the self position control error or the radial position is the same at the two positions, and the influence of the displacement error at the two positions is the tangential direction of the outer circumference 107 due to the inclination angle a, that is, the skew angle is different Angle a1 formed by 102 and the display direction 104 of the head core surface, and angle formed by the tangential direction 102 of the inner circumference 108 and the display direction 104 of the head core surface. (a2) makes a big difference. 2 is for calculating the actual track width 120 (Wr) when having a skew angle angle a at a specific position. When the effective track of the head gap is referred to as W, the radial actual track width on the media 100 is shown. (Wr) is calculated as Wr = Wcosa. In calculating the actual track width (Wr), the effective track width (W) of the head gap is a variable that does not change as already determined at the time of manufacture, and the inner diameter (ID; Inner) in the outer diameter (OD) of the media 100. The problem of how many recording densities are in the section up to the diameter is as the movement from the effective track width (W) of the head core 103 to the inner diameter (ID) from the outer diameter (OD) of the head core (103). The problem is how the actual track width Wr generated is formed. In general, since the head core 103 of the hard disk drive moves nonlinearly between the outer diameter OD and the inner diameter ID around the pivot center of the actuator, the actual track width Wr varies as described above according to the radius. do. That is, the change in the actual track width Wr is large in the inner circumference 108 and small in the outer circumference 10, and the track density determined by this must be adjusted to the large value of the inner circumference 108, so that the loss in the outer circumference 107 is reduced. Since a large amount is generated, a method of minimizing the difference between the actual track width Wr between the outer diameter OD and the inner diameter ID is devised. For example, as shown in FIG. 3, the skew angles a of the outer circumference 107 and the inner circumference 108 on the media 100 are a1 314 and a2 315, respectively. The change rate (δ) for the actual track width (Wr) of

? = | Wcosa2-Wcosa1 | = | cosa2-cosa1 |

However, since the potential displacement error of the actuator is independent of the position, the effect on these two positions when these errors are applied, namely, the magnitude of the positional error signal or the failure of the track seek or the performance degradation related to the leakage of the recording or playback signal The car makes a big difference. In fact, since the head gap surface 406 is formed at right angles to the axis of the head slide in the conventional hard disk drive as shown in FIG. 4A, the radial track width of the outer circumference 107 and the inner circumference 108 is changed, the position in the air position The position error signal (PES) is changed by the change rate (δ) at two positions, and thus, failure in position control, weakening of vibration characteristics, and gain loss of signals during recording / reproduction remain difficult problems. have. However, in the conventional hard disk drive, since there is a margin in the track pitch, the above problem does not appear much. However, when the track pitch decreases due to the high capacity and high density of the hard disk drive, the problem becomes larger.

Accordingly, an object of the present invention is to provide a head for improving position control, vibration characteristics, and signal gain reduction as the actual track width Wr in the orientation direction of the magnetic material of the media and the radial direction of each position on the media is changed. In providing a core.

Another object of the present invention is to make the gap surface of the head core to have an inclination angle (β) from the axial direction of the head slide, but by varying the shape skew angle and the actual magnetization direction angle of the head slide according to the high capacity and high density of the hard disk The present invention provides a head core that eliminates a loss due to a gain of a signal during recording / reproducing due to a decrease in track pitch.

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

5A and 5B are perspective views showing examples of the gap structure of the magnetic head according to the present invention, which are formed so as to be inclined from the gap surface 501 of the head core 103 and the head slide axial direction 507 at (5a). As shown in (5b), it is formed to have an inclination angle β which can be an optimal value from the change of the head core efficiency and the actual track width Wr in the radial direction depending on the position of the spindle motor and the actuator. FIG. 6 is an explanatory diagram for forming an optimal gap plane inclination angle β according to the present invention, and FIG. 7 is a diagram for explaining a calculation process of a calculation formula for calculating the optimum gap plane inclination angle β of FIG. . As shown in FIG. 7, the skew angles a1 and a2 are mechanically moved from the center of the actuator pivot center 1 to the center 701 of the disk of the media 100 and the radius of the media 100, that is, the information recording area. Of the distance r2 from the center 701 of the disk of the media 100 to the outer diameter OD and the distance r1 from the center 701 of the disk of the media 100 to the inner diameter ID. And a skew angle a1 at a distance l3 from the inner diameter ID to the actuator pivot center 10 and a distance l1 from the center 701 of the disk of the media 100 to the actuator pivot center 1. Is calculated. And a skew angle a2 at a distance l2 from the outer diameter OD to the actuator pivot center 10 and a distance l1 from the center 701 of the disk of the media 100 to the actuator pivot center 1. Is calculated. For example, the calculation example of the outer diameter OD skew angle a2 will be described in detail. The distance r2 from the center 701 of the disk of the media 100 to the outer diameter OD and the outer diameter OD are described. The angle formed from the outer diameter OD and the actuator pivot center 10 at the center 701 of the disk of the media 100 from the distance l2 from the actuator pivot center 10 to the actuator pivot center 10 is 90-a2. When Cosine's second law is applied, it is obtained from Equation (2) above.

It can be seen from FIG. 7 that the skew angle a2 is calculated as in the example of (2) above, and the skew angle a1 at the inner diameter ID is also obtained in the same manner as described above. In FIG. 6, when the skew angle is a and the effective track width 612 of the gap is W, the actual track width Wr 618 of the radius 613 is obtained as shown in Equation 3 below.

Here, the relationship between the inclination angle β of the gap surface can be seen. Therefore, as in the example of Equation (3), the effective track width (W) is a value that is determined at the time of manufacturing the gap in the actual head, and is not a variable that often varies depending on the old work, and is determined from the outer diameter (OD) and the inner diameter (ID). As for the skew angles a1 and a2, the distance l1 between the center point 701 of the disc media 100 and the pivot center point 1 of the actuator is known due to the mechanical characteristics of the drive as in the example of Equation (2). When the distance (l2, l3) from the pivot center point 10 to the head gap is determined, the skew from the radius r1, r2 at which the outer diameter OD and the inner diameter ID are located at the center point 701 of the disk media 100 is determined. Angles a1 and a2 are determined. The actual track width Wr is determined according to the change of the radius. In the present invention, the optimum gap plane inclination angle β is calculated in Equation (3) so that the difference between the actual track width Wr is almost the same between the inner diameter ID and the outer diameter OD.

Accordingly, the angles a1 314 and the inner circumference 108 formed by the tangential direction 102 of the outer circumference 107 on the media 100 and the display direction 104 of the head core surface as shown in FIGS. 1 and 3. From the actual track width Wr in the radial direction 313 to the effective track width W from the angle (a2) 315 formed by the tangential direction 102 of < RTI ID = 0.0 >) < / RTI > From the relationship, the rate of change (δ ') is given by the following equation (4).

Here, as an example to compare the application of the inclination angle (β) 616 of the gap surface 501, the skew angle (a1) 314, (a2) (315) of the outer circumference 107 and the inner circumference 108, respectively Assuming 20 ° and 0 ° and assuming that the inclination angle β of the present invention is 10 °, the rate of change δ is not expressed by the following equation (5).

At this time, when the inclination angle (β) 616 is applied, the rate of change (δ ') is given by the following equation (6).

Further, the maximum rate of change at all positions on the media 100 is the difference between the position where the skew angle is 0 ° and the position where the skew angle is 0 ° and 20 ° or 0 ° when the tilt angle β 616 is applied. 616) is reduced by 25% compared to 0.0603 when not applied.

Therefore, in the present invention, the inclination angle is applied to the head core to find and apply the optimum inclination angle β according to the spindle structure and the position of the actuator. In application, as close to zero as for the change rate δ 'as in Equation (6), the change rate δ' is reduced so that the tangential direction 102 of the circumference 107 on the media is Angle (a1) 314 formed by the display direction 104 of the head core surface, the angle formed by the tangential direction 102 of the inner circumference 108 and the display direction 104 of the head core surface ( a2) (315) is inserted into Equation (5) to input a plurality of predetermined inclination angles β, and when the change rate δ 'is optimally close to zero, the value is inclined with respect to the gap surface 501. Determined by (β).

When the inclination angle β is given to the gap surface 501 as in the above example, problems such as failure of position control, weakening of vibration characteristics, and a decrease in gain of a recording / reproducing signal, which are conventional problems, can be solved. It is possible to solve the disadvantage of deterioration of the head caused by the misalignment of the orientation direction of the magnetization material with the gap surface direction.

As long as the gap surface of the head can be applied to all magnetic heads manufactured to have a certain angle with the axial direction of the head slide without departing from the basic technical idea of the present invention, Since the use of the skew angle is not limited, there is less advantage in the positioning of the actuator in the design of the overall shape of the device.

Claims (3)

In the magnetic head core 103 of the recording / reproducing apparatus, the gap surface 501 of the magnetic head core 103 has a change rate δ of the actual track width Wr depending on the radius that varies with the skew angle on the media 100. A magnetic head core in a magnetic recording / reproducing apparatus, characterized in that a gap of a head core (103) having an inclination angle (β) is formed from the axial direction (507) of the head slide. The inclination angle β formed from the gap surface 501 of the magnetic head core 103 and the head slide axial direction 507 is an inner diameter ID from the center 701 of the disk of the media 100. It is determined by the following equation (1) according to the actual track width (Wr) formed by the effective track width (W) in the radial direction between the radius (r1) and the radius (r2) of the outer diameter (OD). A magnetic head core in a magnetic recording / reproducing apparatus. (W: effective track width, Wr: actual track width in the radial direction, a1, a2: inner diameter (ID), skew angle at outer diameter (OD), β: tilt angle) 2. The magnetic recording according to claim 1, wherein the gap surface 501 of the head core 103 formed by the inclination angle β is formed in a gap from the front left side to the rear right direction or from the front right side to the rear left direction. Magnetic head core in the playback device.