JP3940726B2 - Magnetic head and magnetic recording / reproducing apparatus - Google Patents

Description

  The present invention relates to a magnetic recording head used in a magnetic disk device or the like, and in particular, a structure of a recording head capable of stable operation at a high recording density, and a pattern in which tracks are previously formed on the recording head and the medium. The present invention relates to a magnetic recording / reproducing apparatus in combination with a media.

  In recent years, in order to cope with a rapid increase in magnetic recording density in a hard disk drive (HDD), a “quantization dot” in which a magnetic recording medium is composed of an assembly of magnetically independent magnetic particles (magnetic dots) quantized. “Media (hereinafter also referred to as QDM)” has been vigorously developed. In QDM, one bit is composed of one or more magnetic dots. And, since there is no interaction due to exchange coupling with surrounding particles, it has been shown to be effective for thermal demagnetization.

  On the other hand, from the viewpoint of the write magnetic head, when the recording density of the magnetic recording medium is several hundred G (giga) bits per inch, the recording head width becomes less than 0.1 μm, and the dimensional accuracy is 10 nm. I will cut it. For this reason, the yield of manufacturing the magnetic head is deteriorated, which is a serious problem. However, in the QDM in which the recording track of the magnetic recording medium is determined not by the write head width but by the aggregate width of the magnetic particles set in advance on the magnetic recording medium, an overlap threshold (˜50%) for writing is used. ), The head positioning accuracy and dimensional accuracy are relaxed.

When the number of magnetic particles per bit of the recording medium decreases and the behavior of each magnetic particle becomes important in terms of the quality of 1 bit, a recording head shape suitable for it has been proposed. In Patent Document 1, the shape on the leading edge side into which a perpendicular magnetic medium flows is defined as one magnetic particle size, and further tapered, the magnetic particles constituting one bit are gradually reversed in magnetization to be stable 1 The configuration of the main pole for recording bits is described. The trailing edge defining the recording bit is parallel to the track width direction and has a structure in which magnetic particles arranged in parallel to the track width direction are stably written. On the other hand, when one track on the recording medium is composed of 2 to 3 dots of QDM, a close-packed structure is formed and the edge of 1 bit is not parallel to the track width. In this case, in the case of a general recording edge shape (parallel to the track width), the timing for recording all dots is extremely short.
JP 2003-109204 A

  However, in QDM, when the magnetic dots are densely arranged, adjacent dots are arranged at an angle of 120 degrees. For this reason, when writing with a recording head magnetic pole having a track edge perpendicular to the recording track direction as in the conventional head, at least one dot is always unstable in writing, and a writing error is likely to occur due to a recording head misalignment.

  The present invention has been made in consideration of the above circumstances, and provides a magnetic head and a magnetic recording / reproducing apparatus capable of preventing the occurrence of a write error as much as possible even if there is some positional deviation of the recording head. The purpose is to provide.

  A magnetic head according to a first aspect of the present invention includes a recording magnetic pole having a recording track edge, and the recording track edge of the recording magnetic pole appearing on a medium running surface has a shape changed in a bit length direction. To do.

  The recording track edge of the recording magnetic pole appearing on the medium running surface may have a shape having stepped steps in the bit length direction.

  Note that the step position of the stepped step is preferably substantially at the center in the track width direction.

  Note that the recording track edge of the recording magnetic pole appearing on the medium running surface may have a shape having a convex or concave step in the bit length direction.

  The recording track edge of the recording magnetic pole appearing on the medium running surface may have a shape inclined in the bit length direction.

  The magnetic recording / reproducing apparatus according to the second aspect of the present invention includes a recording medium having a recording track having a plurality of magnetic dots in the track width direction of one track, and the magnetic head described above. To do.

  The height of the step is preferably approximately ½ of the arrangement pitch of the magnetic dots arranged in the track width direction.

  According to the present invention, it is possible to prevent the occurrence of a writing error as much as possible even if the recording head is slightly displaced.

  Before describing the embodiment of the present invention, a general relationship among a magnetic head, a recording medium, and information to be written will be described with reference to FIGS. FIG. 23 is a perspective view of the magnetic head as viewed from the side opposite to the medium. In the head traveling direction, the main magnetic pole 1, the exciting coil 15, the return yoke / upper shield 20, and the reproducing element 30 are shown. And a lower shield 40. The side (main magnetic pole) having a small cross-sectional area of the magnetic material magnetically connected by the exciting coil 15 is excited by a signal from the exciting coil 15 to generate a magnetic field, and at the trailing edge (recording edge) 1a. Write information. The width of the trailing edge 1a is the track width of the recording medium 8, and the edge shape is a bit shape. This is shown in section in FIG. The recording medium 8 flows in from the leading edge 1b side of the main pole 1, and writing is performed on the trailing edge (recording edge) 1a side. FIG. 25 is a view of the magnetic head as seen from the medium running surface, and recording bits are written at the trailing edge 1a on the opposite side of the reproducing element 30 on the upper and lower surfaces of the main pole 1.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
A magnetic head according to a first embodiment of the present invention will be described with reference to FIGS. The magnetic head according to the present embodiment has a recording head provided with a main magnetic pole (recording magnetic pole), and FIG. 1 is a plan view of the tailing edge of the main magnetic pole 1 on the medium running surface. The magnetic head according to the present embodiment is used in a quantized dot medium (QDM) in which one track is composed of a plurality of magnetic dots that are closely packed in two rows in the track longitudinal direction, and two magnetic dots constitute one bit. As shown in FIG. 1, the shape of the tailing edge of the main pole 1 on the medium running surface has a stepped step in the bit length direction (track longitudinal direction) with respect to the track width direction. The step height (step) s and the step width W will be described later. In FIG. 1, when the main magnetic pole 1 is fixed, the QDM moves from the bottom to the top. The same applies to other embodiments described later. Further, the tailing edge of the main magnetic pole 1 becomes a recording track edge necessary for recording on the recording medium (QDM).

  In the QDM to which the magnetic head of the present embodiment is applied, as shown in FIG. 2, magnetic dots (hereinafter also referred to as dots) 10 arranged in two rows constituting one track are packed most closely. The magnetic dots 10 are arranged so that the lines connecting the centers of adjacent magnetic dots 10 form 120 degrees. The diameter of one magnetic dot 10 was about 15 nm. Therefore, the track width is about 26 nm. The main magnetic pole 1 of the recording head according to this embodiment has a shape having a step height s of 7.5 nm, which is half the diameter of the magnetic dot 10. FIG. 2 shows the positional relationship between the tailing edge of the main magnetic pole 1 and the magnetic dots 10 in a state where there is no positional shift or timing shift between the main magnetic pole 1 and the QDM. In the present embodiment, it is assumed that data is written as 1 bit in two magnetic dots 10 represented by hatching. As can be seen from FIG. 2, when there is no positional deviation or timing deviation, the magnetic head according to the present embodiment completely overlaps the main magnetic pole 1 and the two magnetic dots 10 to be written, which are represented by diagonal lines. is doing.

  On the other hand, as shown in FIG. 18, the case where the cross-sectional shape of the tailing edge of the main pole 100 is flat is taken as a comparative example. In this comparative example, when one of the magnetic dots to be written by the tailing edge of the recording head is located at the edge even if there is no positional deviation or timing deviation, the main magnetic pole 100 should not be originally written. The overlap amount with one magnetic dot 10 represented by spots is 50%. In general, in the QDM, data can be written to the magnetic dot 10 when the overlap amount between the main magnetic pole 100 and the magnetic dot 10 is 50% or more, but data cannot be written when the overlap amount is less than 50%. For this reason, the magnetization state of the magnetic dots 10 represented by spots that should not be originally written is an unstable state. Therefore, in the comparative example, the tailing edge of the main magnetic pole 100 is always applied to one or both of the magnetic dots to be written and the magnetic dots to be written, regardless of the presence or absence of the positional deviation x. The total area reaches about 50% of one magnetic dot.

  Therefore, when there is no position shift or timing shift, the present embodiment can prevent the tailing edge of the main magnetic pole 1 from being positioned on the magnetic dot 10 that should not be written as compared with the comparative example.

  Next, in the present embodiment, FIG. 3 shows a case where the main magnetic pole 1 has a positional deviation x on the left side. FIG. 3 shows an example in which data is written to magnetic dots indicated by diagonal lines. In FIG. 3, the broken line indicates the tailing edge of the main magnetic pole 1 when the main magnetic pole 1 is not displaced, that is, when it is in the normal position. It can be seen that although the main magnetic pole 1 completely overlaps the magnetic dots 10 indicated by hatching, the tailing edge of the main magnetic pole 1 overlaps the magnetic dots indicated by the spots that should not be written. However, in the present embodiment, it can be seen that even if a position shift occurs to the left by one dot, the maximum overlap is 50% with the magnetic dots indicated by the spots. Therefore, when writing at the correct timing, it can be seen that there is no problem even if it is shifted to the left as long as it is less than one dot.

  On the other hand, in the present embodiment, FIG. 4 shows a case where the main magnetic pole 1 is displaced to the right. FIG. 4 shows an example in which data should be written to the magnetic dots indicated by diagonal lines and the magnetic dots indicated by spots. In FIG. 4, the broken line indicates the tailing edge of the main magnetic pole 1 when the main magnetic pole 1 is not displaced, that is, when it is in the normal position. It can be seen that as the main magnetic pole 1 is displaced to the right, the amount of overlap of the main magnetic pole 1 with respect to the magnetic dots 10 originally indicated by the spots to be written decreases. However, even if it is shifted to the right by one dot, it can be seen that the main magnetic pole 1 and the magnetic dot 10 indicated by the spots to be originally written ensure 50% overlap, so that bit writing can be performed.

  Next, in this embodiment, a timing shift with respect to writing will be described with reference to FIG. Originally, the magnetic dots 10 to be written are indicated by diagonal lines. The writing timing is 50% or more on the magnetic dots 10 indicated by the oblique lines, and the timing at which the tailing edge of the main magnetic pole 1 begins to overlap 50% overlaps the magnetic dots 10 indicated by the spots that should not be written. Y until the timing y1. For this reason, the writing timing is equivalent to one dot.

  On the other hand, as shown in FIG. 19, when the cross-sectional shape of the tailing edge of the main magnetic pole 100 is flat, in the comparative example, in this comparative example, the main magnetic pole 100 is formed on the magnetic dots 10 indicated by spots that should not be written. Since the tailing edge is always applied, as shown in FIG. 19, the writing timing is y until the overlap amount between the magnetic dot 10 and the main magnetic pole 100 indicated by the spots that should not be written becomes 0% to 50%. For this reason, in the comparative example, the writing timing corresponds to half of one dot.

  Therefore, in the present embodiment, the writable timing is twice that of the comparative example.

  Next, the step shape of the tailing edge of the main magnetic pole 1 that is most resistant to displacement will be described. FIG. 6 shows the relationship between the track and the main magnetic pole 1 when a positional deviation occurs, and shows a case where data is written to the magnetic dots in the main track. The diameter of the magnetic dot 10 was d, and the distance between tracks was g. When the main magnetic pole 1 is displaced from the normal position shown by the broken line to the right shown by the solid line, the main magnetic pole 1 and the magnetic shown by the spots are written to the magnetic dots 10 shown by the spots on the adjacent side of the adjacent track. The amount of overlap with dots needs to be less than 50%. When the overlap amount reaches 50%, it is necessary that the overlap amount between the left magnetic dot 10 and the main magnetic pole 1 among the two magnetic bits 10 indicated by hatching in the main track is 50%. Become.

  From the above, the tailing edge of the main magnetic pole 1 having excellent displacement resistance has a step height s that is half the diameter d of the magnetic dot 10, that is, s = d / 2, and further, the step width. w becomes w = d + g / 2 (see FIG. 1). The width of the main magnetic pole 1 is twice the width W of the step.

  As described above, according to the present embodiment, it is possible to prevent the main magnetic pole edge from being positioned on a magnetic dot that should not be originally written, thereby improving the writing stability and improving the bit length direction and Write endurance in the track width direction is improved. Therefore, it is possible to prevent the occurrence of a writing error as much as possible even if the recording head is slightly displaced.

(Second Embodiment)
Next, a magnetic head according to a second embodiment of the invention will be described with reference to FIGS. The magnetic head according to the present embodiment has a recording head having a main pole, and FIG. 7 is a plan view of the tailing edge of the main pole 1A on the medium running surface. As in the case of the first embodiment, the magnetic head according to the present embodiment is composed of a plurality of magnetic dots in which one track is closely packed in two rows in the track longitudinal direction, and two magnetic dots constitute one bit. As shown in FIG. 7, the shape of the medium traveling surface of the tailing edge of the main pole 1A is inclined at a predetermined angle θ with respect to the track width direction. In the present embodiment, the predetermined angle θ is about 30 degrees.

  In this embodiment, FIG. 8 shows the positional relationship between the tailing edge of the main pole 1 and the magnetic dots 10 when there is no positional shift or timing shift between the main magnetic pole 1A and the magnetic dots 10. In this case, the main magnetic pole 1A and the two magnetic dots 10 indicated by oblique lines to be written completely overlap.

  Next, in the present embodiment, FIG. 9 shows a case where the main magnetic pole 1 </ b> A has a misalignment x on the left side. In FIG. 9, the broken line indicates the tailing edge of the main magnetic pole 1 when the main magnetic pole 1 is not displaced, i.e., at the normal position. FIG. 9 shows a case where writing is performed on the magnetic dots 10 indicated by oblique lines. It can be seen that although the main magnetic pole 1A overlaps the magnetic dots 10 indicated by oblique lines, the tailing edge of the main magnetic pole 1A is applied to the two magnetic dots indicated by the spots that should not be written. However, it can be seen that even if the position shifts to the left by one dot, the overlap amount between the two magnetic dots 10 indicated by the spots and the main magnetic pole 1A is only 50% at maximum. Therefore, in this embodiment, when writing is performed at the correct timing, it can be seen that there is no problem even if it is shifted to the left if it is less than one dot.

  On the other hand, in this embodiment, the case where it deviates rightward is shown in FIG. In FIG. 10, the magnetic dots 10 indicated by spots are dots to be written. It can be seen that as the position shifts to the right, the amount of overlap of the main magnetic pole 1A with the two magnetic dots 10 indicated by the spots to be originally written decreases. However, it can be seen that bit writing can be performed because 50% overlap is ensured even if the dot is shifted to the right by one dot.

  Next, the timing shift for writing will be described with reference to FIG. Originally, the magnetic dots 10 to be written are indicated by diagonal lines. The writing timing is 50% or more on the magnetic dots 10 indicated by diagonal lines, from the timing y0 at which the tailing edge of the main magnetic pole 1A starts to overlap, to the timing y1 at which 50% overlap with the magnetic dots 10 indicated by the spots that should not be written. Y during For this reason, the writable timing corresponds to one dot, which is twice that of the comparative example in which the tailing edge of the main pole described in the first embodiment is flat.

  Next, the taper shape of the main magnetic pole 1A that is most resistant to displacement will be described. Since the same principle as described in FIG. 6 of the first embodiment is established, the shape of the tailing edge of the main magnetic pole 1A on the medium traveling surface is the width of the main magnetic pole 1A, that is, the track width as shown in FIG. If 2w, then w = d + g / 2. Further, since the magnetic angle of the magnetic dots 10 is 120 degrees when the magnetic dots 10 are close-packed, the inclination angle θ has the inclination angle of 30 degrees because it does not cross the magnetic dots most, so the taper angle with a large misalignment margin. It becomes.

  As described above, according to the present embodiment, it is possible to prevent the main magnetic pole edge from being positioned on a magnetic dot that should not be originally written, thereby improving the writing stability and improving the bit length direction and Write endurance in the track width direction is improved. Therefore, it is possible to prevent the occurrence of a writing error as much as possible even if the recording head is slightly displaced.

(Third embodiment)
Next, a magnetic head according to a third embodiment of the invention will be described with reference to FIGS.

  In the first and second embodiments, it has been described that the present invention is applied to a recording medium in which the magnetic dots 10 are packed so densely that they come into contact with each other. Even in a state where a gap is opened between the magnetic dots 10 constituting the recording medium, the magnetic head having the main pole having the tailing edge of the step shape of the first embodiment and the inclined shape of the second embodiment is effective. Show. In FIG. 12, the filling rate of magnetic dots is 60%, that is, the state where the circles indicated by broken lines are finely filled in two rows is 100%, and the area of the circle indicated by solid lines representing the magnetic dots 10 is that of the circle indicated by broken lines The case where the area is 60% is shown. Note that the pitch of the magnetic dots 10 is not different from the case of the first and second embodiments. When the filling rate is 100%, the recording medium is the same as in the first and second embodiments.

  FIG. 12 is a diagram illustrating the relationship between the main magnetic pole 1 and the magnetic dots 10 when the main magnetic pole 1 is displaced to the right. The broken line indicates the cross-sectional shape of the tailing edge of the main pole 1 when the main pole 1 is in the normal position. In FIG. 12, the magnetic dots 10 to be originally written are represented by magnetic dots indicated by diagonal lines and magnetic dots indicated by spots. As in FIG. 4 of the first embodiment, the magnetic dots 10 indicated by the spots always maintain 50% overlap, and are in a writable state.

  Even in the case of deviation to the left, as in FIG. 3 of the first embodiment, the magnetic dots 10 indicated by the spots reach 50% overlap with the main pole 1 until the positional deviation is about one dot. Does not cause a write error. Although not shown, the write timing is the same as the pitch of the magnetic dots 10 as in the first embodiment.

  FIG. 13 is a diagram showing the relationship between the main pole 1A and the magnetic dots 10 when the main pole 1A having an inclined shape is displaced to the right as in the second embodiment, and the recording medium shown in FIG. The same recording medium is used. The broken line indicates the cross-sectional shape of the tailing edge of the main magnetic pole 1A when the main magnetic pole 1A is in the normal position. In FIG. 13, the magnetic dots to be written are two dots indicated by spots. As can be seen from FIG. 13, similarly to FIG. 10 of the second embodiment, 50% overlap is ensured up to a shift of about one dot, so that writing is possible.

  In the first and second embodiments, when the filling rate of the magnetic dots becomes 100% or less and a gap is formed between the magnetic dots, a minute positional deviation is absorbed in the gap. The overlap amount does not change due to misalignment. As a result, no further writing errors occur.

  Further, the tailing edge is effective not only in the step shape and the inclined shape, but also in a shape in which the inclined portion and the flat portion are combined as shown in FIG. 20A, or in an arc shape as shown in FIG. . That is, by having a shape shifted in the recording bit length direction at the tailing edge, compared to the recording head in the case of a flat shape in the track width direction (in the case of a shape not shifted in the recording bit length direction) shown in FIG. Even when there is no shift, a more stable recording state is obtained.

(Fourth embodiment)
Next, a magnetic head according to a fourth embodiment of the invention will be described with reference to FIGS. 14 (a), (b) and (c). The magnetic head according to this embodiment has a recording head provided with a main magnetic pole 1B. FIGS. 14A, 14B, and 14C each show a case where the tailing edge of the main magnetic pole 1B is in a normal position. FIG. 6 is a diagram showing a relationship between a tailing edge of a main magnetic pole 1B and a magnetic dot 10 when explaining a writable timing allowable width when the position is shifted by one dot. The magnetic head according to the present embodiment is a quantized dot medium (QDM) in which one track is composed of a plurality of magnetic dots 10 that are closely packed in three rows in the track longitudinal direction, and three magnetic dots constitute one bit. As shown in FIGS. 14A, 14B, and 14C, the shape of the tailing edge of the main pole 1B on the medium traveling surface is convex in the bit length direction (track longitudinal direction) with respect to the track width direction. It has a shape with steps. In FIG. 14B, the broken line indicates the shape of the tailing edge of the main pole 1B on the medium running surface when the main pole 1B is in the normal position.

  In addition, the same thing as what was used in 1st and 2nd embodiment was used as a magnetic dot, and a filling rate (refer the definition demonstrated in 3rd Embodiment) is 100 with the close-packing structure of dot diameter 15nm and 120 degree | times. %.

  In FIG. 14A, the magnetic dots 10 to be written are the three magnetic dots 10 indicated by oblique lines. When there is no position shift, as can be seen from FIG. 14A, the three magnetic dots 10 indicated by hatching and the main magnetic pole 1B completely overlap. When the main magnetic pole 1B is shifted to the right or left by one dot, the write magnetization of the two magnetic dots 10 displayed as spots becomes unstable as can be seen from FIG. 14 (b). However, the write magnetization of the three magnetic dots 10 to be written is stable until the main magnetic pole 1B is shifted by one dot from the normal position. On the other hand, the allowable width of the write timing is one dot, as can be seen from FIG.

  In the fourth embodiment, the shape of the tailing edge of the main magnetic pole 1B on the medium running surface has a step that is convex in the bit length direction with respect to the track width direction. However, the main magnetic pole 1B is configured to have a concave step. Also good. In this case, the magnetic dots to be written are shown in FIG. 14A from two magnetic dots at both ends of the hatched line and one central row of magnetic dots immediately above these two magnetic dots. Composed. In the fourth embodiment, the magnetic dots to be written in FIG. 14A are two magnetic dots at both ends of the hatched line and one magnetic dot immediately below these two magnetic dots. It is composed of magnetic dots indicated by diagonal lines in the center row.

(First modification)
Next, a first modification of the fourth embodiment will be described with reference to FIGS. 15 (a), (b), and (c). 15A, 15 </ b> B, and 15 </ b> C, respectively, in the case where the tailing edge of the main magnetic pole 1 is in a regular position having a stepped shape on the medium traveling surface as in the first embodiment. FIG. 6 is a diagram showing a relationship between a tailing edge of a main magnetic pole 1 and a magnetic dot 10 when a writable timing allowable width is described when the position is shifted by one dot. The magnetic head according to this modification is used for the quantized dot media (QDM) described in the fourth embodiment. In FIG. 15B, the broken line indicates the cross-sectional shape of the tailing edge of the main pole 1 when the main pole 1 is in the normal position.

  In FIG. 15A, the magnetic dots 10 to be written are three magnetic dots 10 indicated by hatching. When there is no position shift, as can be seen from FIG. 15A, the three magnetic dots 10 indicated by hatching and the main magnetic pole 1 completely overlap. When the main magnetic pole 1 is shifted to the right or left by one dot, as shown in FIG. 15B, the write magnetization of the two magnetic dots 10 displayed as spots becomes unstable. However, the write magnetization of the three magnetic dots 10 to be written is stable until the main magnetic pole 1 is shifted by one dot from the normal position. On the other hand, the allowable width of the write timing is one dot, as can be seen from FIG.

  For a recording medium in which one track is composed of a plurality of N rows of magnetic dots, the shape of the tailing edge of the main pole on the medium running surface may have N-1 steps. For example, in the first embodiment, N is 2, and the shape of the tailing edge of the main pole on the medium running surface has one step. In the first modification of the fourth embodiment, N is 3, and the shape of the tailing edge of the main pole on the medium running surface has two steps.

(Second modification)
Next, a second modification of the fourth embodiment will be described with reference to FIGS. 16 (a), (b), and (c). FIGS. 16A, 16B, and 16C each show a case where the tailing edge of the main pole 1A is in a normal position and has a shape inclined with respect to the bit width direction, as in the second embodiment. FIG. 6 is a diagram showing a relationship between a tailing edge of a main magnetic pole 1A and a magnetic dot 10 when a writable timing allowable width is described when the position is shifted by one dot. In FIG. 16B, the broken line indicates the shape of the tailing edge of the main pole 1A on the medium running surface when the main pole 1A is in the normal position. The magnetic head according to this modification is used for the quantized dot media (QDM) described in the fourth embodiment.

  In FIG. 16A, the magnetic dots 10 to be written are three magnetic dots 10 indicated by hatching. When there is no position shift, as can be seen from FIG. 16A, the three magnetic dots 10 indicated by hatching and the main magnetic pole 1A completely overlap. When the main magnetic pole 1A is shifted to the right or left by one dot, as can be seen from FIG. 16B, the write magnetization of the three magnetic dots 10 displayed as spots becomes unstable. However, the write magnetization of the three magnetic dots 10 to be written is stable until the main magnetic pole 1A is shifted by one dot from the normal position. On the other hand, as shown in FIG. 16C, the allowable width of the write timing is one dot.

(Comparative example)
Next, with reference to FIGS. 17A, 17B, and 17C, a case where the shape of the tailing edge of the main pole 100 on the medium running surface is flat will be described as a comparative example. FIGS. 17A, 17B, and 17C illustrate the allowable timing width at which writing is possible when the tailing edge of the main pole 100 of the comparative example is in a normal position and the position is shifted by one dot. FIG. 6 is a diagram showing the relationship between the tailing edge of the main magnetic pole 100 and the magnetic dots 10 in the case of The magnetic head according to this comparative example is used for the quantized dot media (QDM) described in the fourth embodiment.

  In FIG. 17 (a), the magnetic dots 10 to be written are two magnetic dots 10 with diagonal lines and one magnetic dot with dots. When there is no position shift, as can be seen from FIG. 17A, there are one or two magnetic dots that are unstable in writing, that is, one that has an overlap amount with the main magnetic pole 100 of less than 50%. Will do. When the main magnetic pole 100 is shifted to the right or left by one dot, as can be seen from FIG. 17B, the magnetic dots that are unstable in writing as in the case of no positional deviation, One or two magnetic dots having an overlap amount with the magnetic pole 100 of less than 50% exist. On the other hand, as shown in FIG. 17C, the allowable width of the write timing is half of one dot.

  As described above, according to the present embodiment, it can be seen that even when applied to a recording medium in which one bit has a three-dot configuration, the stability against misalignment and the allowable timing for writing timing are large.

(Fifth embodiment)
Next explained is a magnetic recording / reproducing apparatus according to the fifth embodiment of the invention. The magnetic head according to the first to fourth embodiments described with reference to FIGS. 1 to 16 and FIG. 20 can be incorporated into a magnetic head assembly integrated with a recording / reproduction, for example, and mounted on a magnetic recording / reproduction apparatus.

  FIG. 21 is a main part perspective view illustrating a schematic configuration of such a magnetic recording / reproducing apparatus. That is, the magnetic recording / reproducing apparatus 150 according to the present embodiment is an apparatus using a rotary actuator. In the figure, a magnetic disk 200 for longitudinal recording or perpendicular recording is mounted on a spindle 152 and rotated in the direction of arrow A by a motor (not shown) that responds to a control signal from a drive device control unit (not shown). The magnetic disk 200 has a recording layer for longitudinal recording or perpendicular recording. In the magnetic disk 200, a head slider 153 that records and reproduces information stored in the magnetic disk 200 is attached to the tip of a thin film suspension 154. Here, the head slider 153 mounts the magnetic head according to any of the above-described embodiments near the tip thereof.

  When the magnetic disk 200 rotates, the medium facing surface (ABS) of the head slider 153 is held with a predetermined flying height from the surface of the magnetic disk 200.

  The suspension 154 is connected to one end of an actuator arm 155 having a bobbin portion for holding a drive coil (not shown). A voice coil motor 156, which is a kind of linear motor, is provided at the other end of the actuator arm 155. The voice coil motor 156 is composed of a drive coil (not shown) wound around the bobbin portion of the actuator arm 155, and a magnetic circuit composed of a permanent magnet and a counter yoke arranged so as to sandwich the coil.

  The actuator arm 155 is held by ball bearings (not shown) provided at two locations above and below the fixed shaft 157, and can be freely rotated and slid by a voice coil motor 156.

  FIG. 22 is an enlarged perspective view of the magnetic head assembly ahead of the actuator arm 155 as viewed from the disk side. That is, the magnetic head assembly 160 has an actuator arm 151 having, for example, a bobbin portion that holds a drive coil, and a suspension 154 is connected to one end of the actuator arm 155.

  A head slider 153 including any of the magnetic heads described above is attached to the tip of the suspension 154. A reproducing head may be combined. The suspension 154 has a lead wire 164 for writing and reading signals, and the lead wire 164 and each electrode of the magnetic head incorporated in the head slider 153 are electrically connected. In the figure, reference numeral 165 denotes an electrode pad of the magnetic head assembly 160.

FIG. 3 is a diagram showing the shape of the tailing edge of the main pole of the magnetic head according to the first embodiment of the invention on the medium running surface. The figure which shows the relationship between the main magnetic pole and magnetic dot when the main magnetic pole of the magnetic head by 1st Embodiment is not displaced. The figure which shows the relationship between the main magnetic pole and magnetic dot when the main magnetic pole of the magnetic head by 1st Embodiment has shifted | deviated to the left one dot. The figure which shows the relationship between the main magnetic pole and magnetic dot when the main magnetic pole of the magnetic head by 1st Embodiment has shifted | deviated to the right of 1 dot. FIG. 6 is a diagram for explaining allowable write timing of the magnetic head according to the first embodiment. The figure explaining the suitable shape of the tailing edge of the main pole of the magnetic head by 1st Embodiment. The figure which shows the shape in the medium running surface of the tailing edge of the main pole of the magnetic head by 2nd Embodiment of this invention. The figure which shows the relationship between the main magnetic pole and magnetic dot when the main magnetic pole of the magnetic head by 2nd Embodiment is not displaced. The figure which shows the relationship between the main magnetic pole and magnetic dot when the main magnetic pole of the magnetic head by 2nd Embodiment has shifted | deviated to the left by 1 dot. The figure which shows the relationship between the main magnetic pole and magnetic dot when the main magnetic pole of the magnetic head by 2nd Embodiment has shifted | deviated to the right of 1 dot. FIG. 10 is a diagram for explaining an allowable write timing of a magnetic head according to a second embodiment. The figure which shows the relationship between the main magnetic pole and magnetic dot when the main magnetic pole of the magnetic head by 3rd Embodiment has shifted | deviated to the right by 1 dot. The figure which shows the relationship between the main magnetic pole and magnetic dot when the main magnetic pole of the magnetic head by the modification of 3rd Embodiment has shifted | deviated to the right by 1 dot. The figure which shows the relationship between the main pole and magnetic dot of the magnetic head by 4th Embodiment. The figure which shows the relationship between the main pole and magnetic dot of the magnetic head by the 1st modification of 4th Embodiment. The figure which shows the relationship between the main pole and magnetic dot of the magnetic head by the 2nd modification of 4th Embodiment. The figure explaining the relationship between the main pole and a magnetic dot in the comparative example of 4th Embodiment. The figure explaining the relationship between the main magnetic pole and magnetic dot in the comparative example of 1st Embodiment when the main magnetic pole is not displaced. The figure explaining the allowable write-in timing in the comparative example of 1st Embodiment. The figure which shows the suitable shape of the tailing edge of the main pole of the magnetic head by the modification of 3rd Embodiment. FIG. 2 is a perspective view of a main part showing a schematic configuration of a magnetic recording / reproducing apparatus. The enlarged perspective view which looked at the magnetic head assembly ahead from an actuator arm from the disk side. The perspective view which shows the general relationship between a magnetic head, a recording medium, and information to be written. FIG. 4 is a cross-sectional view of the magnetic head cut along a plane perpendicular to the recording medium and along the medium traveling direction. The top view of the magnetic head seen from the medium running surface side.

Explanation of symbols

1 Main magnetic pole 1A Main magnetic pole 1B Main magnetic pole 10 Magnetic dot

Claims (6)

  A magnetic head comprising a recording magnetic pole having a recording track edge, wherein the recording track edge of the recording magnetic pole appearing on a medium running surface has a stepped step in the bit length direction.   2. The magnetic head according to claim 1, wherein the step position of the stepped step is substantially at the center in the track width direction.   A magnetic head comprising a recording magnetic pole having a recording track edge, wherein the recording track edge of the recording magnetic pole appearing on the medium running surface has a shape having a convex or concave step in the bit length direction. A recording medium having a recording track comprising a plurality of magnetic dots packed closest in the track width direction of one track;
A magnetic head comprising a recording magnetic pole having a recording track edge, wherein the recording track edge of the recording magnetic pole appearing on the medium running surface is inclined by 30 degrees in the bit length direction;
A magnetic recording / reproducing apparatus comprising: A recording medium having a recording track comprising a plurality of magnetic dots packed closest in the track width direction of one track;
A magnetic head according to any one of claims 1 to 3,
A magnetic recording / reproducing apparatus comprising:   6. The magnetic recording / reproducing apparatus according to claim 5, wherein the height of the step is approximately ½ of the arrangement pitch of the magnetic dots arranged in the track width direction.

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