JP4442395B2 - Optically assisted magnetic recording head and magnetic recording apparatus - Google Patents

Description

  In the present invention, when recording information on a magnetic recording medium, the target recording portion is locally heated by light irradiation, and the coercive force of the target recording portion is locally reduced by this heating to record information. The present invention relates to a magnetic recording head and a magnetic recording apparatus for performing optically assisted magnetic recording.

There is an increasing demand for an increase in recording capacity for recording media, that is, a higher recording density.
Magnetic recording on a magnetic recording medium such as a magnetic tape or a hard disk is formed by a magnetic recording head by changing the direction of magnetization of the ferromagnetic recording magnetic layer of the magnetic recording medium according to the recorded information. This is done by forming information pits by recording magnetic domains.

  The limit of the information recording density in such a recording method by magnetization is determined by the fluctuation of the boundary generated in the recording magnetic section by different magnetization, that is, the disturbance or uncertainty of the boundary surface of the magnetic section. In addition, the fluctuation appears as jitter of the recording information signal, which causes problems such as a decrease in S / N. This fluctuation of the boundary can be suppressed by reducing the size of the magnetic particles existing in the magnetic domain, that is, the magnetic particles constituting the magnetic layer.

  However, in a magnetic recording medium, regardless of the recording mode, that is, for example, whether in-plane recording or perpendicular magnetization recording, in order to achieve high recording density and low noise, the coercive force of the recording magnetic layer Need to be increased. And, when the size of the magnetic particles is reduced in order to suppress the fluctuation of the boundary described above, the thermal stability is lowered, and the change in the magnetization direction due to heat is likely to occur. Therefore, it is required to form the recording magnetic layer of the magnetic recording medium with a magnetic material having a higher coercive force.

For example, if the 1-bit recording area is reduced to such an extent that it is composed of 100 or more magnetic particles, [Equation 1], which is a condition in which recorded information is not lost due to thermal disturbance, is difficult to be satisfied. The above-described change in the magnetization direction of each particle due to heat, that is, the disappearance of recorded information due to so-called thermal fluctuations easily proceeds. In [Formula 1], Ku is the magnetic anisotropy energy, V is the volume of the material particle, k _B is the Boltzmann factor, and T is the absolute temperature.

  Therefore, as described above, in order to reduce the fluctuation of the boundary of the magnetic domain (bit) that determines the recording density of the magnetic recording medium and further improve the stability of information recording and long-term storage, the coercive force, that is, the magnetic anisotropy It is necessary to configure the recording medium using a magnetic material with high energy. However, in this case, the magnetic field required to perform the desired magnetization, that is, the recording of information also increases, so that a sufficiently strong magnetic field can be applied to all magnetic materials suitable for constituting the recording area. It is difficult to develop a recording head.

In order to solve such a problem, there has been proposed a heat-assisted recording method in which a magnetic recording is performed by heating a recording portion by applying a magnetic field to locally reduce the coercive force.
As this heat-assisted recording method, a method of providing a resistance heater on a magnetic head, a method of supplying warm air, a laser beam irradiation method, and the like have been proposed.
Among these methods, the method using laser light is superior to other methods from the viewpoint of time required for energy transmission. For this reason, in a practical heat-assisted recording method, heat assist by laser light is considered promising.

  As a light (thermal) assisted recording method using this laser beam, a method of mounting a laser on the magnetic recording head itself, a method of condensing and irradiating the laser beam with a lens, or irradiating the laser beam through an optical fiber Possible methods.

  In this optically assisted magnetic recording by light irradiation, a sufficient amount of heat is applied to a portion where a target recording magnetic field is applied to reduce the coercivity by laser light irradiation, and in an adjacent portion other than the target recording portion. However, in order to avoid a decrease in coercive force, it is desirable that the light irradiation location and the recording magnetic field application location basically coincide with each other in addition to narrowing the light spot. For this purpose, it is desirable to irradiate the target location by actively condensing using an optical lens, rather than by a method of irradiating laser light directly or through an optical fiber.

  However, when a light spot of laser light is formed using a normal far-field type optical lens, the light spot becomes larger than the recording magnetic field spot by the magnetic recording head. There is a problem that heating of the magnetic recording head cannot be sufficiently avoided and that most of the collected light is blocked by the magnetic recording head structure arranged close to the recording medium. In order to block such light irradiation by the magnetic recording head structure, when irradiation is performed from the opposite side of the magnetic recording head structure with the recording medium sandwiched between them, the alignment of the magnetic spot and the light spot becomes complicated and difficult. Produce.

On the other hand, a recording method for performing optically assisted magnetic recording by forming a light spot of a laser beam using a near-field type optical lens has been proposed (see, for example, Patent Document 1 and Patent Document 2).
In this case, the light spot of the laser beam can be narrowed down sufficiently, but in this case as well, the magnetic recording head structure shields the optical path of the laser beam as in the case of the far-field type optical lens. There's a problem. Also. Since the near-field type optical lens is arranged sufficiently close to the magnetic recording medium, the structural problem caused by the ideal arrangement position of the magnetic recording head structure and the optical lens overlapping each other and the assembly manufacturing Problems arise in complexity and accuracy.
Japanese Patent No. 2809688 Japanese Patent No. 3441417

The present invention is to solve the above-mentioned problems in a magnetic recording head and a magnetic recording apparatus for optically assisted magnetic recording.
That is, the present invention effectively avoids the light irradiation obstruction caused by the magnetic field application even though the recording magnetic field application and the light irradiation for the heat assist through the optical lens are performed from the same side of the magnetic recording medium. The light utilization efficiency can be sufficiently increased, and effective heat assist can be achieved.

  In addition, the present invention can simplify the structure and simplify the assembly and manufacture despite the use of a near-field optical lens as the optical lens, and can further reduce the magnetic field generation. The recording magnetic domains can be further miniaturized to increase the recording density.

A first optically assisted magnetic recording head according to the present invention comprises an objective lens and a hemispherical or super hemispherical optical lens, and has an effective numerical aperture of 1.0 or more, and a condensing lens for generating near-field light. The hemispherical or super hemispherical optical lens is configured such that incident light from the spherical surface is condensed on the bottom surface facing the spherical surface, and the perpendicular magnetic recording The recording-type magnetic head has a single magnetic pole wound with a coil, the single magnetic pole is disposed in the optical lens, and the auxiliary magnetic pole for recording assistance magnetically coupled to the single magnetic pole is provided in the optical lens. The auxiliary magnetic pole for recording assist is formed by a soft magnetic material layer deposited along the spherical outer surface of the optical lens, and the coil is disposed on the bottom side of the optical lens. Features.

In the optically assisted magnetic recording head according to the present invention, the single magnetic pole is disposed on an axis that is close to and parallel to the optical axis of the incident light, and the magnetic field generation tip of the single magnetic pole is the optical lens of the optical lens. It is the structure located in the bottom face, It is characterized by the above-mentioned.
In the optically assisted magnetic recording head according to the present invention, the bottom surface of the optical lens has a protruding shape that protrudes at a central portion, and the tip of the single magnetic pole is positioned at the tip of the protruding shape. It is characterized by that.
In the optically assisted magnetic recording head, the tip of the single magnetic pole is tapered.
According to the present invention, in the optically assisted magnetic recording head, a wiring pattern for connecting the coil to an external power source is disposed on the bottom surface of the optical lens.
In the optically assisted magnetic recording head according to the present invention, at least a part of the coil is formed so as to enter the inside from the bottom surface of the optical lens.
In the optically assisted magnetic recording head according to the present invention, the coil is entirely formed outside the bottom surface of the optical lens.
According to the present invention, in the optically assisted magnetic recording head, the coil is disposed outside the optical path on the bottom surface side of the optical lens.
The second optically assisted magnetic recording head according to the present invention includes an objective lens and a hemispherical or super hemispherical optical lens, has an effective numerical aperture of 1.0 or more, and collects light for generating near-field light. The hemispherical or super-hemispherical optical lens has a lens system and a perpendicular magnetic recording type magnetic head, and incident light from the spherical surface is condensed on a bottom surface facing the spherical surface, and the vertical The magnetic recording type magnetic head has a single magnetic pole around which a coil is wound, the single magnetic pole is disposed in the optical lens, and the auxiliary magnetic pole for recording auxiliary magnetically coupled to the single magnetic pole is the optical The auxiliary magnetic pole for recording assistance is constituted by a soft magnetic member separate from the optical lens, and the coil is arranged on the bottom surface side of the optical lens.
According to the present invention, in the second optically assisted magnetic recording head, a part of the auxiliary magnetic pole is disposed outside the bottom surface of the optical lens.

A first magnetic recording apparatus according to the present invention includes a laser light source, an optically assisted magnetic recording head, and a gap adjusting unit that defines or controls a gap between the optically assisted magnetic recording head and a magnetic recording medium. The assist magnetic head includes an objective lens and a hemispherical or super hemispherical optical lens, has an effective numerical aperture of 1.0 or more, a condensing lens system for generating near-field light, and a perpendicular magnetic recording magnetic head The hemispherical or super hemispherical optical lens is configured such that incident light from the spherical surface is collected on the bottom surface facing the spherical surface, and the perpendicular magnetic recording type magnetic head has a coil wound thereon. A single magnetic pole that is rotated, the single magnetic pole is disposed in the optical lens, and a recording auxiliary sub-magnetic pole that is magnetically coupled to the single magnetic pole is disposed outside the optical lens. Sub magnetic pole The formed of a soft magnetic material layer which is deposited along the spherical outer surface of the optical lens, wherein the coil is disposed on the bottom surface side of the optical lens, the recording of information on the magnetic recording medium, by the gap adjusting means In a state where the gap of the optically assisted magnetic recording head with respect to the magnetic recording medium is adjusted, the laser light from the laser light source is condensed and irradiated onto the magnetic recording medium by the condenser lens system, and the thin film magnetic head Information is recorded by generating a magnetic field.
A second magnetic recording apparatus according to the present invention comprises a laser light source, an optically assisted magnetic recording head, and a gap adjusting means for defining or controlling a gap between the optically assisted magnetic recording head and the magnetic recording medium, The optically assisted magnetic head is composed of an objective lens and a hemispherical or super hemispherical optical lens, and has an effective numerical aperture of 1.0 or more, a condensing lens system for generating near-field light, and a perpendicular magnetic recording type magnetism. The hemispherical or super hemispherical optical lens is configured such that incident light from the spherical surface is collected on the bottom surface facing the spherical surface, and the perpendicular magnetic recording magnetic head has a coil. A single magnetic pole that is wound, the single magnetic pole is disposed in the optical lens, and a recording auxiliary sub-magnetic pole that is magnetically coupled to the single magnetic pole is disposed outside the optical lens; For The magnetic pole is composed of a soft magnetic member separate from the optical lens, the coil is disposed on the bottom surface side of the optical lens, and information is recorded on the magnetic recording medium by the gap adjusting means. In the state where the gap of the optically assisted magnetic recording head is adjusted, the laser light from the laser light source is condensed and irradiated onto the magnetic recording medium by the condenser lens system, and the magnetic field is generated from the thin film magnetic head. It is characterized by recording information.

According to the present invention, in the magnetic recording apparatus, the gap adjusting means includes a flying slider, and the optically assisted magnetic head is mounted on the flying slider.
In the magnetic recording apparatus, the magnetic recording apparatus further comprises a detecting means for detecting the reflected light of the laser beam irradiated on the magnetic recording medium, and the gap servo signal of the gap adjusting means is generated by a detection output from the detecting means. It is characterized by obtaining.
According to the present invention, in the magnetic recording apparatus, the optically assisted magnetic head is mounted on a biaxial actuator, and the biaxial adjustment of the optical axis direction of the optically assisted magnetic head and a direction perpendicular thereto is performed by the biaxial actuator. It is characterized by
Further, the present invention provides the magnetic recording apparatus, further comprising: a means for detecting the reflected light of the laser light applied to the magnetic recording medium, and detecting the output of the optically assisted magnetic head from the detection output by the means for detecting the reflected light. A focusing servo signal for the magnetic recording medium by an optical system is obtained.
Further, the present invention provides the magnetic recording apparatus, further comprising: a means for detecting the reflected light of the laser light applied to the magnetic recording medium, and detecting the output of the optically assisted magnetic head from the detection output by the means for detecting the reflected light. A tracking servo signal for applying a magnetic field to the magnetic recording medium by a thin film magnetic head for recording is obtained.
Further, the present invention provides the magnetic recording apparatus, comprising: a means for detecting the reflected light of the laser beam irradiated on the magnetic recording medium, and the unevenness of the land and groove in the direction crossing the longitudinal direction of the recording track. Is applied to the magnetic recording medium by the thin film magnetic head for recording of the optically assisted magnetic head from the detection output of the reflected light of the laser beam to the magnetic recording medium. The tracking servo signal is obtained.
In the magnetic recording apparatus, the magnetic recording medium may have a soft magnetic layer below the recording layer.

  As described above, the magnetic recording head according to the present invention is based on the near-field light, that is, the near-field method by the focusing system having an effective numerical aperture of 1.0 or more by the objective lens and the hemispherical or super-hemispherical optical lens. In addition, the spot diameter can be reduced so that the condensing position in the lens and the condensing position in the magnetic recording medium coincide with each other, and highly efficient light (heat) assist recording can be performed. Since the single magnetic pole of the perpendicular magnetic recording magnetic pole is arranged in the hemisphere or super hemisphere optical lens on the optical axis or at a position close to the optical axis, the focusing position and the recording application position are almost ideal positions. Can be formed.

  In addition, since the coil for generating a magnetic field in the single magnetic pole is disposed on the bottom side of the hemisphere or super hemisphere, that is, in the vicinity of the tip of the single magnetic pole, the use efficiency of the magnetic field generated from this coil can be improved, and the coil can be used as a lens. By arranging it in the vicinity of the light condensing part on the bottom surface side, it is possible to arrange the entire coil or almost all of it outside the optical path.

  The single magnetic pole for generating the recording magnetic field is sufficiently reinforced and supported by being embedded in the lens, so that at least its cross section can be made sufficiently small and light shielding can be reduced. Is. By making the tip of the single magnetic pole thinner, it is possible to more effectively avoid light blocking and concentrate the recording magnetic field.

As described above, according to the configuration of the present invention, the optical lens and the magnetic recording head are integrated so as to satisfy the respective performances, the coercive force is reduced only in a predetermined recording portion of the magnetic recording medium, and Information can be recorded on the magnetic recording medium without lowering the temperature before the magnetic field is applied, and the light shielding can be sufficiently reduced along with the reduction of the light spot on the magnetic recording medium, thereby sufficiently enhancing the heat assist effect. Since the recording magnetic field spot can be reduced at the same time, the improvement of the thermal assist effect described above can reduce the recording bit, improve the resolution, reduce the recording magnetic field, etc. Densification is achieved.
According to the configuration of the present invention, the single magnetic pole for generating the recording magnetic field is arranged in the hemispherical or super hemispherical optical lens, thereby simplifying the structure and simplifying the assembly and manufacturing.

  The magnetic recording apparatus according to the present invention includes the above-described optically assisted magnetic recording head according to the present invention, and thus has the above-described effects. Further, in this way, a laser using a condensing lens system is used. By adopting a configuration by light irradiation, the positional relationship between the optically assisted magnetic head and the magnetic recording medium can be controlled by detecting the reflected light from the magnetic recording medium, as in the conventional optical pickup such as an optical disk. Servo signals such as focusing, tracking, and the distance between the optically assisted magnetic head and the magnetic recording medium, that is, gap control can be obtained. Therefore, the positional relationship between the optically assisted magnetic head and the magnetic recording medium can be set accurately, and excellent optically assisted magnetic recording can be performed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to these embodiments.
An embodiment of a magnetic recording apparatus according to the present invention will be described together with an embodiment of an optically assisted magnetic recording head according to the present invention with reference to the schematic configuration diagram of FIG.

In this embodiment, the magnetic recording apparatus 12 includes a laser light source 6, an optically assisted magnetic recording head 1, an arrangement portion 51 of the magnetic recording medium 11, and a laser light source 6 and an optically assisted magnetic recording head 1. A beam splitter 7, a reflected light detecting means 8 for detecting reflected light (returned light) irradiated to the magnetic recording medium 11 from the light-assisted magnetic recording head 1, and the light-assisted magnetic head 1. Gap adjusting means 62 that regulates or controls the fine distance from the magnetic recording medium 11 is provided.
Then, a control means (not shown) is provided that calculates a detection signal obtained by the reflected light detection means 8 and performs positional relationship between the optically assisted magnetic head 1 and the magnetic recording medium 11, that is, focusing and tracking control. As will be described later, this control means can be constituted by, for example, a biaxial actuator 41 equipped with, for example, the optically assisted magnetic head 1 that can also serve as the gap adjusting means 62 described above.

  As shown in a schematic perspective view of FIG. 2, the optically assisted magnetic recording head 1 includes, for example, an objective lens 3 using a so-called aspherical lens and a hemispherical or super hemispherical optical lens (hereinafter referred to as a hemispherical / superhemispherical optical lens) 2. A condensing lens system 4 having an effective numerical aperture of 1.0 or more, and a single magnetic pole 22 constituting a perpendicular magnetic recording type magnetic head 20 in the hemisphere / super hemisphere optical lens 2; The coil 24 wound around this is disposed. The coil 24 is disposed on the bottom side of the hemisphere / super hemisphere optical lens 2.

The magnetic recording medium 11, such as a hard disk, may have a structure having a soft magnetic layer 11b and a recording layer 11c having a high magnetic permeability on a substrate 11a made of glass, for example.
The magnetic recording medium 11 is mounted on a magnetic recording medium placement unit 51 that can rotate the magnetic recording medium 11 by a spindle motor 10.

  The coil 24 is supplied with a recording signal current from the signal power source 5, thereby inducing a signal magnetic field to the single magnetic pole, causing magnetization concentration at the tip of the single magnetic pole 22 facing the magnetic recording medium 11. A perpendicular recording magnetic field is applied to the 11 magnetic recording layers 11c. At this time, when the soft magnetic layer 11b exists on the back surface of the recording layer 11c, a more perpendicular magnetic flux is applied to the recording layer 11c due to a mirror image effect. In addition, the recording magnetic field generated by the mirror image effect by the soft magnetic layer 11b is distributed only in a range approximately the same as the tip diameter of the single magnetic pole 22, so that the recording magnetic field can be locally generated by miniaturizing the tip of the single magnetic pole 22. Can be applied.

  In the above configuration, the lens system 4 including the combination of the objective lens 3 and the hemisphere / super hemisphere optical lens 2 has a so-called SIL (Solid Immersion Lens) or Super-SIL configuration used in near-field optical recording, and has an effective numerical aperture. Near-field light exceeding 1.0 is generated.

Usually, the diameter of a focused spot by a single objective lens can be reduced only to about λ / NA _{obj when} the wavelength of light is λ and the aperture ratio of the objective lens is NA _{obj due} to the diffraction limit of light. However, according to the above-described SIL lens system and Super-SIL lens system, when the refractive index of the optical lens is n at the focal plane, that is, the bottom surface of the hemisphere / super hemisphere optical lens, the spot diameters are 1 / n and 1 / n. Reduction to n ² can be achieved.
Further, when the bottom surface of the optical lens having these structures is opposed to the recording medium and the gap with the recording medium is set to λ / 10 or less, it is the same as that on the bottom surface of the optical lens due to the imaging action by the near-field light. In addition, light spots having a diameter of 1 / n and 1 / n ² can be formed on the recording medium.

  In the configuration of FIG. 1 described above, the laser light from the laser light source 6 passes through the beam splitter 7, is introduced into the condensing lens system 4, is condensed by the objective lens 3, and is a hemisphere / super hemisphere optical lens. 2 is incident. The incident light forms a condensing spot on the bottom surface of the hemisphere / super hemisphere optical lens 2 and the magnetic recording medium 11 that is in close proximity to the bottom surface. Therefore, a fine spot of the laser beam is formed at or near the target recording portion where the recording magnetic field is applied to the magnetic recording medium 11 by the single magnetic pole 22 for generating a magnetic field of the recording thin film magnetic head 20 arranged on the bottom surface side. As a result, the temperature of the intended perpendicular recording portion is raised, and the coercive force of the recording portion can be locally reduced. That is, light (heat) assist is performed.

A part of the light used for the light assist is reflected from the surface of the magnetic recording medium 11 and introduced into the beam splitter 7 through the lens system 4, whereby the optical path is separated from the incident optical path and reflected light. It is introduced into the detection means 8.
The reflected light detection means 8 detects the far field component of the reflected light by a plurality of divided photodiodes, for example, in the same manner as the light detection means in an optical pickup in a normal optical disk. Each of these outputs is used to perform a required calculation, for example, focusing servo by the differential spot size method, for example, DPD (Differential Phase Detector) method, and further, for example, in the longitudinal direction of the recording track in the magnetic recording medium 11 A magnetic recording medium having land-and-groove irregularities in the crossing direction is used, and tracking servo can be performed by applying a push-pull method or the like.
Further, in the configuration of the present invention, the amount of reflected light of the near field component of the reflected light from the surface of the magnetic recording medium changes in proportion to the distance between the condenser lens system 4 and the magnetic recording medium 11, that is, the gap amount. By utilizing this, a gap servo signal is obtained from the amount of reflected light of the near field component.
The focusing control, tracking control, and gap control can be performed by a biaxial actuator described later.

In the configuration described above, the hemisphere / super hemisphere optical lens 2 constituting the optically assisted magnetic head 1 according to the present invention can take various configurations. For example, FIG. 3A shows an example of the hemisphere / super hemisphere optical lens 2. As shown in the schematic bottom view and in the schematic cross-sectional view of FIG. 3B, a projecting shape portion 2b projecting outward from the shape of the condensing portion at the center of the bottom surface 2a is formed, and a condensing point is formed here. Can be.
In this example, the single magnetic pole 22 is disposed on the optical axis O of the laser light introduced into the hemisphere / super hemisphere optical lens 2 or on an axis parallel thereto, and the tip thereof is the bottom surface 2a of the cylindrical projecting shape portion 2b. It is a case where it arrange | positions so that it may become a position which corresponds to or substantially corresponds.
In this case, the coil 24 is arranged around the outer periphery of the protruding portion 2b, that is, wound around the outside of the lens 2, and as a result, the single magnetic pole 22 is arranged almost on the central axis of the coil.

In the example shown in FIG. 3A, the hemispherical / super hemispherical optical lens 2 is supported by, for example, a support tool 71 arranged around the hemisphere / super hemisphere optical lens 2. For example, an electrode 70 connected to the external signal power source 5 is formed on the support 71.
On the other hand, the hemisphere / super hemisphere optical lens 2 is formed with a wiring pattern 72 that electrically connects the terminal of the coil 24 to the electrode 70.
The wiring pattern 72 connected to the coil 24 can be formed simultaneously with the electrode 70 by using, for example, a conductive layer.

For example, as shown in FIG. 4A, a cross-sectional view of the hemisphere / super-hemisphere optical lens 2, the coil 24 is disposed inside the protruding portion 2 b of the bottom surface 2 a, that is, within the hemisphere / super-hemisphere optical lens 2. As shown in FIG. 4B, a part is inside, a part is outside, that is, for example, the center side of the coil 24 enters the hemisphere / super hemisphere optical lens 2, and the outer periphery is the hemisphere / super hemisphere optical lens 2. It is also possible to adopt an arrangement configuration expressed from
Further, although not shown, it is also possible to provide, for example, a ring-shaped concave portion on the bottom surface of the hemispherical / super hemispherical optical lens 2 without providing the protruding shape portion 2b and insert the coil 24 therein.
In any case, the coil 24 can be mechanically supported on the bottom surface side of the optical lens 2 and is arranged on the bottom side in this manner, so that, for example, as schematically shown in FIG. The position near the tip where the incident laser beam L1 to the lens 2 is arranged outside the optical path of the laser beam L2 introduced into the optical lens 2, the coil 24 is prevented from blocking the optical path, and the magnetic field of the single magnetic pole 22 is generated. Therefore, the generated magnetic field can be effectively used as a recording magnetic field.

  The protruding portion 2b of the bottom surface 2a of the optical lens 2 has a conical shape, a truncated conical shape, a prismatic shape, or a curved surface such as a conical shape that gradually protrudes from the peripheral edge of the bottom surface of the optical lens. It can be a shape.

  The specific size and shape of the optical lens 2 is, for example, a hemispherical shape having a radius of 500 μm, the protruding shape portion 2 b of the optical lens 2 is a cylindrical protruding shape having a radius of 50 μm, and the single magnetic pole 22 has a cross section at the tip portion on the bottom side. A trapezoidal shape with a side of about 100 nm is formed, and a width of a portion away from the tip toward the opposite rear end by 10 μm or more is about 10 μm, and the shape can be tapered toward the tip. And the front-end | tip of this single magnetic pole 22 can be set as the structure corresponded with the bottom face 2a in the protrusion-shaped part 2b.

  According to the above-described configuration, the single magnetic pole 22 is disposed on or in parallel with the optical axis of the transmitted light L2 that passes through the optical lens 2 according to the incident laser L1 from the objective lens 3, and other than this. Since the members, for example, the coil 24 and the like are disposed outside the optical path, the optical path can be effectively prevented from being blocked, the decrease in the amount of transmitted light L2 is suppressed, and the light spot on the bottom surface of the optical lens 2 can be narrowed down sufficiently. It is possible that the spot shape is good.

  In the above-described configuration, it is necessary to accurately match the optical spot formation position and the magnetic field application position relationship with the optimum position relationship with respect to a predetermined portion of the magnetic recording medium 11. In order to increase the recording efficiency, it is desirable that the recording magnetic field / application position and the light spot center be as close as possible. This is because as the distance between the two increases, the temperature gradient and the highest temperature reach, and the recording efficiency decreases. However, in terms of the ease of arranging the magnetic poles so as to avoid the shielding of light by the magnetic poles, it is desirable that the recording magnetic field application position and the light spot center be separated by a required amount. From the result of analyzing the temperature rise characteristic of the medium surface by the laser beam spot, it is considered that the distance between the recording magnetic field application center and the beam spot center is several hundred nm or less, preferably about 50 to 100 nm.

The configuration described above is such that the recording magnetic field is obtained from the single magnetic pole 22 in the perpendicular magnetic recording type recording head 20, but a schematic plan view is shown in each of FIGS. As shown in a schematic cross-sectional view, a recording aid that forms a closed magnetic path including the soft magnetic layer 11b of the magnetic recording medium 11 with respect to the perpendicular magnetic field applied to the magnetic recording medium 11 by the single magnetic pole 22 and strengthens the magnetic field. The auxiliary magnetic pole 23 can be arranged.
This auxiliary recording magnetic pole 23 is arranged outside the hemispherical / super hemispherical optical lens 2 and is configured to be provided outside the optical lens 2 by being magnetically coupled to the rear end of the single magnetic pole 22. it can.

In the example shown in FIG. 5, the sub magnetic pole 23 is configured to be deposited by a soft magnetic material layer from the top opposite to the bottom surface 2 a along the spherical surface of the optical lens 2 from the bottom surface side.
In the example shown in FIG. 6, the tip 23 a of the sub-magnetic pole 23 in FIG. 5 is arranged to extend to a position facing the tip of the single pole 22 up to a required distance. 11, the magnetic path between the single magnetic pole 22 and the sub magnetic pole 23 is efficiently generated around the soft magnetic layer 11 b, and the perpendicular magnetic field from the single magnetic pole 22 efficiently crosses the recording layer 11 c of the magnetic recording medium 11. be able to.
In addition, as shown in FIG. 7, the sub magnetic pole 23 made of a soft magnetic member separate from the optical lens 2 may be arranged outside the optical lens 2. Even in this case, as described with reference to FIG. 6, the tip portion 23 a of the sub magnetic pole 23 can be extended to a position relatively close to the tip of the single magnetic pole 22.
Further, according to the configuration of FIG. 7, the sub magnetic pole 23 itself has a mechanical strength, so that, for example, the sub magnetic pole 23 can also serve as the support 71 of the optical lens 2. In this case, the cross-sectional area of the auxiliary magnetic pole 23 can be made sufficiently large, and the magnetic resistance can be reduced.

  Further, when the tip portion 23a of the sub magnetic pole 23 is extended to the bottom surface 2a of the optical lens 2 and further to the protruding shape portion 2b, the distance between the sub magnetic pole 23 and the magnetic recording medium 11 is made small, and thus the above-mentioned. The closed magnetic path of the single magnetic pole 22, the recording layer 11c, and the soft magnetic layer 11b can be formed more effectively.

  That is, since a gas having a low permeability, for example, air exists between the sub magnetic pole 23 and the magnetic recording medium 11, the thickness of the gas layer, that is, the distance between the sub magnetic pole 23 and the recording layer 11c is determined. It is preferable to be small.

  However, if the tip 23a of the sub magnetic pole 23 is arranged at a position where the transmitted light L2 transmitted through the optical lens 2 conflicts with the light spot formed on the bottom surface 2a of the optical lens 2, the purpose of the magnetic recording medium 11 is improved. Therefore, the distance from the center of the bottom surface of the optical lens 2 to the end of the sub magnetic pole 23 is set to 10 μm or more in consideration of a manufacturing margin at the time of manufacturing and assembly. It is preferable.

Next, the results of studying the magnetic characteristics of the magnetic recording head according to the present invention will be described.
That is, the magnetic characteristics of the magnetic recording head according to the present invention, that is, the configuration including the single magnetic pole 22 with and without the sub magnetic pole 23 were examined.
In addition, the magnitude | size of the magnetic field in examination of a magnetic characteristic was calculated by the simulation using MAXWEL two-dimensional magnetic field analysis software (ANSOFT company).

FIG. 8 is a diagram showing a simulation result for studying a magnetic recording head according to the present invention having a single magnetic pole 22 that does not include the sub magnetic pole 23 described above.
In FIG. 8, the single magnetic pole 22 has a plate-like configuration having an infinite thickness in the direction orthogonal to the paper surface, and the single magnetic pole 22 has a configuration extending in the direction orthogonal to the paper surface to the left and right across the single magnetic pole 22. Conductive wires 24a that are energized in opposite directions are arranged in a direction orthogonal to the paper surface with 22 interposed therebetween, and a magnetic field is applied from the tip of the single magnetic pole 22 toward the surface of the magnetic recording medium 11 by energizing the conductive wires 24a. Is made.
The conducting wire 24a corresponds to the coil 24 in the first configuration example described above, and generates a magnetic field similar to that of the coil 24 with respect to the single magnetic pole 22 having an infinite thickness in a direction orthogonal to the paper surface. Is.

9A and 9B are a schematic cross-sectional view showing the shape of a single magnetic pole in this examination example and an enlarged cross-sectional view of the tip portion thereof.
In this examination example, as shown in FIG. 9A, the single magnetic pole 22 has a width (a in the figure) of 20 μm, the distance between the single magnetic pole 22 and the conductor 24a (b in the figure) is 20 μm, and the height of the conductor 24a. The thickness was 2 μm. In the magnetic recording medium 11, the recording layer 11c is omitted, and the soft magnetic layer 11b (not shown) is the uppermost layer.

Further, as shown in FIG. 9B, the tip of the single pole 22 is particularly tapered, and the tip (d in the figure) has a height of 500 nm, and the soft pole that constitutes the magnetic recording medium 11 from the tip of the single pole 22. The distance to the magnetic layer 11c (e in the figure) is 50 nm, the width (f in the figure) is 400 nm, the thickness of the soft magnetic layer 11c (g in the figure) is 300 nm, and the transmission of the single magnetic pole 22 and the soft magnetic layer 11a is made. The magnetic susceptibility was 1000.
Under this condition, a current of 250 mA was passed through the conductor 24a, and the magnitude of the magnetic field exerted on the recording layer was measured based on the assumption that the recording layer was formed immediately above the soft magnetic layer 11c. The size was 9 kOe.

  From the relationship between the recording current of the magnetic recording head and the generated magnetic field in a conventional magnetic recording head (K. Ise, K. Yamakawa, K. Ouchi, H. Muraoka, Y. Sugita, and Y. Nakamura: IEEE Trans. Magn. 36 2520 (2000)), when a current of 100 mA is applied to a coil wound 6T (turns) under the same conditions as the configuration shown in FIG. 9B to generate a recording current load of 0.6 AT, 8 kOe It is said that a recording magnetic field is generated.

  In the first study example shown in FIGS. 9A and 9B described above, since a current of 250 mA is passed through the coil wound by 1T, the recording current load becomes 0.25AT. According to the head, that is, according to the magnetic recording head in the first configuration example described above, it can be confirmed that a sufficient recording magnetic field can be formed as compared with the conventional magnetic recording head.

Next, the results of studying the information surface density and the recording temperature will be described.
[Equation 2] is generally used as a condition that information recorded on the magnetic recording medium is not lost due to thermal disturbance. The loss of recorded information due to heat is because the magnetization direction of each particle constituting the recording layer of the magnetic recording medium changes due to, for example, thermal fluctuation. In [Expression 2], Ku is the magnetic anisotropy energy, V is the volume of the material particle, k _B is the Boltzmann factor, and T is the absolute temperature.

In Equation 2, since the numerator on the left side shows the magnetic anisotropy energy of one magnetic particle and the denominator on the left side shows thermal disturbance, if there is a difference of about 40 times between them, the recorded information Is held stably.
Here, since KbT = 4.0E-14 (erg) at room temperature, KuV needs to be 40 KbT = 1.6E-12 (erg) or more.

On the other hand, in the structure of a hard disk that is a kind of magnetic recording medium, if the bit length corresponding to the recording magnetic domain is b (nm) and the track width perpendicular to the track extending direction by the recording magnetic domain is w (nm), The areal density can be expressed as A (Tb / in ² ) = 645 / (b · w). If the thickness of the recording layer is t (nm), the number N of particles per bit can be expressed as N = tbw / V, and the relationship between Ku and the information surface density can be expressed as [Equation 3].

Here, since noise increases when the number of particles is too small, it is necessary to reduce noise by setting N to about 100 and t to about 10. Therefore, since the magnitude of anisotropic energy for stably holding information is proportional to the information surface density, for example, to realize the information surface density of A = 1 (Tb / in ² ). Anisotropy energy of 2.5E7 (erg / cm ³ ) is required. This anisotropic energy can be expressed by [Equation 4] using an anisotropic magnetic field Hk (kOE). Ms is the magnetization (emu / cm ³ ) of the magnetic recording medium.
Since Ms is generally 1000 (emu / cm ³ ), the anisotropic magnetic field Hk is 50 (kOe) from [Equation 4].

  As a material having such a high anisotropic magnetic field, for example, the compound FePt is known. However, in the current magnetic recording head and magnetic recording system, the upper limit of the recording magnetic field generated and applied is about 8 kOe. Therefore, since it is difficult to record information on a recording layer made of such a material with a normal magnetic recording method, it is necessary to record information by optically assisted (thermally assisted) magnetic recording with heating by light irradiation. It becomes.

  The temperature dependence of the anisotropic magnetic field of a material in which Ni is mixed with this compound FePt (J.-U. Thiele, KR Coffey, MF Toney, JA Hedstrom, and AJ Kellock: J. Appl. Phys. 91, 6595 (2002)), for example, by heating a recording medium having an anisotropic magnetic field of 40 kOe to 540 K at a room temperature to a material in which Ni is mixed with the compound FePt, an anisotropic magnetic field necessary for recording is obtained. It is considered that recording can be performed with a recording magnetic field of about 8 kOe.

Next, a description will be given of the results of examining the temperature rise by laser light for performing optically assisted magnetic recording on the magnetic recording medium in the above-described single magnetic pole configuration.
FIG. 10 is a diagram illustrating a simulation result of a change in the temperature of the recording medium when the magnetic recording medium is irradiated with 5 mW of laser light for 2 n seconds in the above-described first configuration example.

  In FIG. 10, the distance between the light spot formed by the laser beam on the magnetic recording medium and the magnetic field spot formed on the magnetic recording medium by the applied magnetic field from the tip of the single magnetic pole is used as a parameter, and this distance is 0 nm. (▽ in the figure), 20 nm (X in the figure), 50 nm (□ in the figure), 70 nm (+ in the figure), and 100 nm (◇ in the figure) Shows the results of calculating the temperature rise of the magnetic recording medium by laser light.

It can be confirmed that the temperature rise is sufficiently efficient even when the distance between the light spot by the laser beam and the magnetic field spot by the applied magnetic field is any of 0 nm to 100 nm.
On the other hand, in the manufacture of the magnetic recording head and the magnetic recording apparatus, the larger the distance between the two, the more margin can be provided. Therefore, the distance between the light spot by the laser beam and the magnetic field spot by the applied magnetic field is 50 nm. It is considered to be preferably about ˜100 nm. In this case, under the above conditions, the temperature is 250 ° C. to 450 ° C., which is a practical temperature increase for optical (heat) assisted magnetic recording.

FIGS. 11 and 12 are diagrams showing simulation results of magnetic field generation when the sub magnetic pole 23 is coupled to the single magnetic pole 22.
In this case as well, as in FIG. 8, the single magnetic pole 22 has a plate-like structure having an infinite thickness in the direction orthogonal to the paper surface, and extends in the direction orthogonal to the paper surface on both sides of the single magnetic pole 22. The existing conductors 24a that are energized in opposite directions are arranged.

In this examination example, the configuration and dimensions of the single magnetic pole 22 and the magnetic recording medium 11 are the same as those in FIG. The sub magnetic pole 23 is magnetically coupled to the single magnetic pole 22 at the top of the single magnetic pole 22 and has an end facing the magnetic recording medium 11 at a position 520 μm away from the single magnetic pole 22. The distance between the single magnetic pole 22 and the sub magnetic pole 23 is that the sub magnetic pole 23 is formed away from the optical lens 2 because the diameter of the optical lens 2 in the second and third configuration examples is 1000 μm. Thus, 520 μm is selected as sufficiently larger than 500 μm.
In this simulation, the sub magnetic pole 23 has an end facing the magnetic recording medium 11 along the outer surface of the optical lens 2, and the shape of the sub magnetic pole 23 is slightly different from that shown in FIGS. Although it is different, this is due to the convenience of simulation, and it is a difference that is considered to have no extreme influence on the calculation.

Under this condition, a current of 250 mA was passed through the conductor 24a, and the magnitude of the magnetic field exerted on the recording layer was calculated based on the assumption that the recording layer was formed immediately above the soft magnetic layer 11c. The size was 9.6 kOe in the example of FIG. 11, and 11 kOe in the example of FIG.
Therefore, in the magnetic recording head according to the present invention, although accompanied by a slight decrease in the amount of transmitted light L _3, as compared with the case of single-pole configuration corresponding to FIG. 8 without the auxiliary magnetic pole 23 is provided, corresponding to FIG. 11A In the case of the configuration example having the sub magnetic pole 23 of FIG. 6, the recording magnetic field can be increased by about 7%, and in the case of the configuration example of FIG. 7 corresponding to FIG. 11B by about 22%.

  Incidentally, in the case of these configuration examples having the sub magnetic pole formed at least partially exposed from the optical lens, for example, the recording magnetic field described above is larger than in the case of the first configuration example having only a single magnetic pole. As the increase increases the upper limit of the recording density proportional to the increase, it is considered that the recording density is substantially improved. In addition, since the recording magnetic field can be further increased, magnetic recording can be performed with a smaller temperature increase range than in the case of a configuration with only a single magnetic pole. %, Power consumption can be reduced and optical system design can be simplified.

  As described above, the magnetic recording head according to the present invention can select the magnetic field strength, the magnetic field spot shape, the transmitted light amount, the light spot shape, etc., depending on the presence / absence of the sub magnetic pole and the selection of the formation position thereof. Various aspects and modifications can be made according to the priority of each property and the purpose of use of the magnetic recording head.

  The above-described optically assisted magnetic head 1 is mounted on a biaxial actuator that also serves as a gap adjusting means 62 that regulates or controls the positional relationship with the magnetic recording medium 11 for focusing adjustment, tracking adjustment, and further focusing adjustment. The distance from the magnetic recording medium, that is, the gap can be adjusted by superimposing.

  The focusing adjustment is performed using the far field component of the reflected light from the medium surface so that the imaging point of the lens coincides with the medium recording layer. By the focusing adjustment, the distance between the lens bottom surface and the medium surface is controlled to the range of the focal depth of the lens, that is, about ± 100 nm. For example, the distance between the lens bottom surface and the medium surface needs to be controlled to about 20 ± 2 nm. As the gap detection signal, the reflected light amount of the near field component from the medium surface described above can be used. Since the distance between the lens bottom and the medium surface is close to the order of nanometers, the gap control is not only important in terms of generating a near-field, but also increases the tribological reliability at the lens surface / medium surface interface. It is extremely important to secure.

13A and 13B are perspective views showing the biaxial actuator that also serves as the gap adjusting means 62 described above together with the relationship with the magnetic recording medium 11, and are perspective views showing the biaxial actuator mechanism of the biaxial actuator. .
In this biaxial actuator, the biaxial actuator mechanism 41 includes a coarse actuator mechanism 42, and coarse movement adjustment is performed by the coarse actuator mechanism 42 in the radial direction of the magnetic recording medium 11, for example, a magnetic disk.
The biaxial actuator mechanism 41 is mounted with the condensing lens system 4, and as shown in FIG. 13B, the biaxial actuator mechanism 41 is supported by the support spring 41a, for example, in the support 29 by the condensing lens system 4. Then, the first and second voice coil motors 41b and 41c can adjust the movement in the direction horizontal to the medium surface of the magnetic recording medium 11, that is, the tracking direction (shown by the arrow x) by the tracking servo signal described above. The drive is performed in the optical axis direction, that is, the direction perpendicular to the medium surface, that is, the focus direction (shown by the arrow y) by the focus servo signal and the gap servo signal.

  FIG. 14 is a side view, partly in section, of the optically assisted magnetic recording head 1 according to the present invention in which the gap adjusting means 62 for keeping the gap constant has a floating slider configuration. In this floating type configuration, the optically assisted magnetic head 1 is mounted on the slider 14 supported on the free end of the suspension 13, and the slider 14 floats by moving or rotating the magnetic recording medium facing the magnetic head 1. The gap between the optically assisted magnetic head 1 and the medium 11 is defined by the flying height.

  The magnetic recording apparatus 1 according to the present invention is not limited to the active control type configuration controlled by the condenser lens system 4 and the optically assisted magnetic recording head 1 by the actuator described above, but the magnetic recording facing the hemisphere / super hemisphere lens 2. It is also possible to adopt a passive control type structure in which the medium 11 is levitated by moving or rotating (illustrated by an arrow).

  In the magnetic recording head according to the present invention, a wiring pattern for transmitting the current from the signal power source 5 to the coil 24 is formed at the bottom of the optical lens 2, for example. It is possible to obtain a desired position and shape so as to be out of the optical path of the transmitted light, that is, not to block the transmitted light.

  Further, the magnetic recording head according to the present invention can be configured as a magnetic recording / reproducing device by arranging the magnetic reproducing head together with the magnetic recording head inside or outside the optical lens. And changes can be made.

1 is a schematic configuration diagram of a magnetic recording apparatus having an optically assisted magnetic recording head according to the present invention. It is a typical perspective view of the principal part of FIG. FIGS. A and B are a schematic top view and a schematic side view, respectively, showing the configuration of another example of the magnetic recording head according to the present invention. FIGS. A and B are schematic cross-sectional views illustrating hemispherical or super hemispherical optical lenses of the optically assisted magnetic head according to the present invention, respectively. FIGS. A and B are a schematic bottom view and a schematic sectional view, respectively, showing the configuration of another example of the magnetic recording head according to the present invention. FIGS. A and B are a schematic bottom view and a schematic sectional view, respectively, showing the configuration of another example of the magnetic recording head according to the present invention. FIGS. A and B are a schematic bottom view and a schematic sectional view, respectively, showing the configuration of another example of the magnetic recording head according to the present invention. It is a figure which shows the result of the simulation of the magnetic field distribution of the magnetic recording head of a single pole structure for use in explaining the present invention. FIGS. A and B are explanatory views of the relationship between the tip of the single magnetic pole and the magnetic recording medium. It is a figure which shows the result of having examined the temperature rise by the laser beam for performing optically assisted magnetic recording with respect to a magnetic recording medium. It is a figure which shows the result of the simulation of the magnetic field distribution in the other example of the magnetic recording head by this invention. It is a figure which shows the result of the simulation of the magnetic field distribution in the other example of the magnetic recording head by this invention. FIGS. A and B respectively show a schematic perspective view of an example of an optical pickup using a biaxial actuator of a magnetic recording head according to the present invention, facing the magnetic recording medium, and a biaxial actuator constituting the optical pickup. It is a schematic perspective view which shows the structure of an example. 1 is a schematic configuration diagram of an example of a magnetic recording head according to an embodiment of the present invention that is floated by movement or rotation of an opposing magnetic recording medium.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Optical assist type magnetic head, 2 ... Hemispherical or super hemispherical optical lens, 3 ... Objective lens, 4 ... Condensing lens system, 5 ... Signal power supply, 6 ... Light source unit, 7 ... beam splitter, 8 ... reflected light detection means, 10 ... spindle motor, 11 ... magnetic recording medium (arrangement unit), 11a ... substrate, 11b ... soft Magnetic layer, 11c ... Recording layer, 20 ... Perpendicular magnetic recording type magnetic head, 22 ... Single magnetic pole, 23 ... Sub magnetic pole, 24 ... Coil, 41 ... Biaxial actuator mechanism, 42 ... Coarse actuator, 51 ... Arrangement part of magnetic recording medium, 62 ... Gap adjusting means

Claims (19)

An objective lens and a hemispherical or super hemispherical optical lens, having an effective numerical aperture of 1.0 or more, a condensing lens system for generating near-field light, and a perpendicular magnetic recording type magnetic head;
The hemispherical or super hemispherical optical lens is configured such that incident light from the spherical surface side is collected on the bottom surface side facing the spherical surface side,
The perpendicular magnetic recording type magnetic head has a single magnetic pole wound with a coil,
The single pole is disposed in the optical lens;
A recording auxiliary sub-magnetic pole magnetically coupled to the single magnetic pole is disposed outside the optical lens, and the recording auxiliary sub-magnetic pole is applied by a soft magnetic material layer deposited along the spherical outer surface of the optical lens. Formed,
An optically assisted magnetic recording head, wherein the coil is disposed on the bottom side of the optical lens.   The single magnetic pole is disposed on an axis that is close to and parallel to the optical axis of the incident light, and a magnetic field generation tip of the single magnetic pole is positioned on the bottom surface of the optical lens. 2. The optically assisted magnetic recording head according to 1.   2. The light-assist type according to claim 1, wherein the bottom surface of the optical lens has a protruding shape that protrudes at a central portion, and the tip of the single magnetic pole is positioned on the bottom surface of the protruding shape portion. Magnetic recording head.   2. The optically assisted magnetic recording head according to claim 1, wherein the tip portion of the single magnetic pole is tapered.   The optically assisted magnetic recording head according to claim 1, wherein a wiring pattern for connecting the coil to an external power source is disposed on a bottom surface of the optical lens.   2. The optically assisted magnetic recording head according to claim 1, wherein at least a part of the coil is formed so as to enter the inside from the bottom surface of the optical lens.   2. The optically assisted magnetic recording head according to claim 1, wherein the coil is entirely formed outside the bottom surface of the optical lens.   2. The optically assisted magnetic recording head according to claim 1, wherein the coil is disposed outside the optical path on the bottom side of the optical lens. An objective lens and a hemispherical or super hemispherical optical lens, having an effective numerical aperture of 1.0 or more, a condensing lens system for generating near-field light, and a perpendicular magnetic recording type magnetic head;
The hemispherical or super hemispherical optical lens is configured such that incident light from the spherical surface side is collected on the bottom surface side facing the spherical surface side,
The perpendicular magnetic recording type magnetic head has a single magnetic pole wound with a coil,
The single pole is disposed in the optical lens;
A recording auxiliary sub-magnetic pole magnetically coupled to the single magnetic pole is disposed outside the optical lens, and the recording auxiliary sub-magnetic pole is constituted by a soft magnetic member separate from the optical lens ,
An optically assisted magnetic recording head, wherein the coil is disposed on the bottom side of the optical lens. The optically assisted magnetic recording head according to claim 9, wherein a part of the sub magnetic pole is disposed on a bottom surface of the optical lens. A laser light source;
An optically assisted magnetic recording head;
Gap adjusting means for defining or controlling the gap between the optically assisted magnetic recording head and the magnetic recording medium;
The optically assisted magnetic recording head includes an objective lens and a hemispherical or super hemispherical optical lens, and has an effective numerical aperture of 1.0 or more, a condensing lens system for generating near-field light, and perpendicular magnetic recording. A magnetic head,
The hemispherical or super hemispherical optical lens is configured such that incident light from the spherical surface side is collected on the bottom surface side facing the spherical surface side,
The perpendicular magnetic recording type magnetic head has a single magnetic pole wound with a coil,
The single pole is disposed in the optical lens;
A recording auxiliary sub-magnetic pole magnetically coupled to the single magnetic pole is disposed outside the optical lens, and the recording auxiliary sub-magnetic pole is applied by a soft magnetic material layer deposited along the spherical outer surface of the optical lens. Formed,
The coil is disposed on the bottom side of the optical lens;
Recording of information on the magnetic recording medium is performed with the laser light from the laser light source being emitted by the condensing lens system in a state where the gap adjustment means has adjusted the gap of the optically assisted magnetic recording head with respect to the magnetic recording medium. A magnetic recording apparatus for recording information by generating a magnetic field from the perpendicular magnetic recording type magnetic head by condensing and irradiating a magnetic recording medium. A laser light source;
An optically assisted magnetic recording head;
Gap adjusting means for defining or controlling the gap between the optically assisted magnetic recording head and the magnetic recording medium;
The optically assisted magnetic recording head includes an objective lens and a hemispherical or super hemispherical optical lens, and has an effective numerical aperture of 1.0 or more, a condensing lens system for generating near-field light, and perpendicular magnetic recording. A magnetic head,
The hemispherical or super hemispherical optical lens is configured such that incident light from the spherical surface side is collected on the bottom surface side facing the spherical surface side,
The perpendicular magnetic recording type magnetic head has a single magnetic pole wound with a coil,
The single pole is disposed in the optical lens;
A recording auxiliary sub-magnetic pole magnetically coupled to the single magnetic pole is disposed outside the optical lens, and the recording auxiliary sub-magnetic pole is constituted by a soft magnetic member separate from the optical lens,
The coil is disposed on the bottom side of the optical lens;
Recording of information on the magnetic recording medium is performed with the laser light from the laser light source being emitted by the condensing lens system in a state where the gap adjustment means has adjusted the gap of the optically assisted magnetic recording head with respect to the magnetic recording medium. A magnetic recording apparatus for recording information by generating a magnetic field from the perpendicular magnetic recording type magnetic head by condensing and irradiating a magnetic recording medium. 13. The magnetic recording apparatus according to claim 11 , wherein the gap adjusting unit includes a flying slider, and the optically assisted magnetic recording head is mounted on the flying slider. Comprising a means for detecting the reflected light of the laser beam applied to the magnetic recording medium,
The magnetic recording apparatus according to claim 11 , wherein a gap servo signal of the gap adjusting unit is obtained by a detection output from the detecting unit. The light-assisted magnetic recording head is mounted on the biaxial actuator, or claim 11, characterized in that Nasaru biaxial adjustment in a direction perpendicular the optical axis direction and therewith of the optical-assisted magnetic recording head by the biaxial actuator 12. The magnetic recording device according to any one of 12 above. Comprising a means for detecting the reflected light of the laser beam applied to the magnetic recording medium,
13. The focusing servo signal for the magnetic recording medium by the condensing lens system of the optically assisted magnetic recording head is obtained from the detection output of the reflected light detection means. 13 . Magnetic recording device. Comprising a means for detecting the reflected light of the laser beam applied to the magnetic recording medium,
13. A tracking servo signal for applying a magnetic field to the magnetic recording medium by the perpendicular magnetic recording type magnetic head of the optically assisted magnetic recording head is obtained from a detection output of the reflected light detection means . 2. A magnetic recording apparatus according to item 1 . Comprising a means for detecting the reflected light of the laser beam applied to the magnetic recording medium,
A magnetic recording medium having land-and-groove irregularities formed in a direction intersecting with the longitudinal direction of the recording track is used, and the light assist is detected from the detection output of the reflected light of the laser beam on the magnetic recording medium by the detection means. The magnetic recording apparatus according to claim 11, wherein a tracking servo signal for applying a magnetic field to the magnetic recording medium by the perpendicular magnetic recording type magnetic head of the magnetic recording head is obtained. The magnetic recording apparatus according to claim 11 , wherein the magnetic recording medium has a soft magnetic layer below the recording layer.

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