KR20080032229A - Information recording device and head - Google Patents

Abstract

In an information recording device, an LD (100) located at a position a predetermined distance away from a swing arm (20) outputs laser light, and the laser light is applied through a beam converter (90) and a mirror (80) to a spherical aberration lens (70) for causing spherical aberration. The information recording device causes the laser light having transmitted through the spherical aberration lens to enter into a light entry opening of a slider (60) at a certain angle (vertical). This applies the light to that position of a recording medium where information is recorded, thermally assisting information recording.

Description

Information recording device and head {INFORMATION RECORDING DEVICE AND HEAD}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an information recording apparatus or the like which controls an arm provided with a head for recording information on a recording medium and records information on the recording medium. The present invention relates to an information recording apparatus and head capable of solving the problem of thermal fluctuations and enabling high-speed recording and reproducing of information on a recording medium.

In recent years, with increasing capacities of magnetic disk devices and the like in computer equipment, recording densities of recording media on which information is recorded have increased. In the magnetic disk device, reading of information on the recording medium is performed by the magnetic head. 19 shows an overview of the magnetic disk apparatus. As shown in the figure, the magnetic disk device rotates a swing arm equipped with a slider to record and reproduce information. This swing arm is lightweight, compact, and has the advantage of enabling high-speed seek and high-speed recording and reproducing.

Here, the head for recording and reproducing information will be described. 20 is a diagram showing the configuration of a head called a terminal pole type vertical recording head. This head is manufactured using a thin film manufacturing technique using lithography together. In an actual magnetic disk device, this head is made in a part of a chip about 1 mm each called a slider which adds a pad structure for floating.

The head has a main stimulus and a secondary stimulus. The large magnetic pole of the rectangular parallelepiped shown in FIG. 20 is an auxiliary magnetic pole for feeding back a magnetic flux, and the taper slightly small magnetic pole of a tip | tip is a main magnetic pole, and the coil is wound around the auxiliary magnetic pole and the main magnetic pole. Thus, by narrowing the tip of the main stimulus, the magnetic field is concentrated and a recording magnetic field is generated. On the other hand, the auxiliary stimulation serves to pick out the magnetic flux generated by the main stimulus, and to return the selected magnetic flux to the coil and the main stimulus once again. Also behind the auxiliary magnetic pole is the same metal as the lower shield magnetic pole. A magnetoresistive element (MR element, GMR element, TMR element, etc.) is disposed between the lower shield and the auxiliary magnetic pole to form a regenerated magnetic head.

Since the main magnetic pole is an independent pole (single magnetic pole) corresponding to the N pole or the S pole of the magnet and records information on the recording medium, this head is called a terminal pole head or a terminal pole type vertical recording head (hereinafter, Simply labeled terminal pole head). When information is recorded using this terminal pole head, a magnetic field is generated from the main magnetic pole, and the information is recorded on the recording medium to which the recording film is added. In addition to Co (Cobalt), Pt (Platinum), and the like, which are conventionally used magnetic disk materials, thin films of hard magnetic metals such as Te (Tellurium), Fe (Ferrum <iron>) and Co can also be used as recording films. This recording film becomes a magnetic recording layer. The magnetic recording layer is superimposed on a soft magnetic thin film such as Permalloy to form a recording medium for vertical recording. The recording medium is placed in the vicinity of the terminal electrode head, and the recording medium is rotated in the direction of the arrow shown in FIG. 20 to record information.

By the way, in order to increase the recording capacity per unit area applied to a recording medium such as a magnetic disk, it is necessary to increase the surface recording density. However, as the recording density is increased, the recording area occupied by one bit on the recording medium ( Bit size). When this bit size is reduced, the energy of one bit of information is close to the thermal energy at room temperature, and the information of the so-called thermal potato, in which the information by the recorded magnetization is reversed or disappeared due to thermal fluctuations, A problem arises.

That is, in order to increase the recording density, when the bit size is reduced, it is necessary to make the magnetic particles finer. In order to solve the problem of thermal fluctuation described above, if the volume of the miniaturized magnetic particles is V, the anisotropic constant is Ku, and the energy of the temperature at which the thermal fluctuation problem occurs is kT, It is necessary to make rain 60 or more.

Here, in order to make the ratio of KuxV to kT 60 or more, it is necessary to increase the value of Ku. However, in order to increase the value of Ku, it is necessary to increase the magnetic field used when recording the information on the recording medium, and since the recording magnetic head for generating such a magnetic field cannot be realized, the large size of the recording medium is large. Capacity was difficult.

Therefore, a method of combining the magnetic recording method and the thermal assist recording method has been proposed. Here, the heat assist is to heat the medium by irradiating light. In order to use a recording medium having a high Ku, that is, a high coercive force, it is used to irradiate a light beam locally in the vicinity of the recording place and to heat it, and to lower the coercive force of the heating unit to a recording magnetic field that can be realized or lower. This enables magnetic recording by the recording magnetic head.

Considered as an optical system of such thermal assist, in Patent Application No. Hei 9-326939, as shown in Fig. 21, a mirror, a lens, and the like are disposed on a swing arm, and a magnetic field by an air core coil is used. For example, laser light output from a semiconductor laser (hereinafter referred to as LD) or the like may be auxiliaryly irradiated to an information recording position of a recording medium and recorded. This example is applied to magneto-optical disks such as M0 (Magneto-Optic).

Similarly, in patent document 1, the optical system containing LD is arrange | positioned on a swing arm. In addition, Patent Literature 2 discloses a technique in which a laser beam is irradiated to a recording medium using an optical fiber to perform thermal assist, and magnetic recording is performed.

In addition, Patent Document 3 discloses a technique of irradiating a laser beam to a recording medium and performing magnetic recording by using a linear actuator, although it is an example of an optical magnetic disk device.

Patent Document 1: Japanese Unexamined Patent Publication No. 2001-34982

Patent Document 2: Japanese Unexamined Patent Publication No. 2002-298302

Patent Document 3: Japanese Unexamined Patent Publication No. Hei 6-131738

However, in the above-described prior art, in order to irradiate the recording medium with laser light for thermal assist, an optical system or an optical fiber is disposed on the swing arm, so that the swing arm becomes heavy. there was.

In this manner, the swing arm becomes heavy, and there is a problem in that the advantage of the magnetic disk device, that is, the fast recording or the fast reproducing of information by the fast seek of the swing arm, cannot be performed.

It is also conceivable to install a linear actuator in place of the swing arm provided in the magnetic disk device, but it is very difficult to design a new magnetic disk device using the linear actuator, which is not practical in terms of design time and design cost. In addition, the access speed and the like become very slow, and the high speed access performance of the magnetic disk is impaired.

That is, the problem of the thermal fluctuation which arises in the said recording medium is solved by irradiating a laser beam to a recording medium, such as a magnetic disc, and performing thermal assist, and recording information, without impairing the advantage of the conventional magnetic disk apparatus. It is a very important task.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and an object thereof is to provide an information recording apparatus and a head capable of solving the problem of thermal fluctuations and recording information on a recording medium at a high density without impairing the advantages of the magnetic disk apparatus. do.

MEANS TO SOLVE THE PROBLEM In order to solve the above-mentioned subject, and to achieve an objective, this invention is an information recording apparatus which controls the arm in which the head which records information is provided in the recording medium, and records the information on the said recording medium. And light incidence means disposed at a stop position other than the rotating arm, and incident light to the head, and light incident on the head by the light incidence means at a position to record information of the recording medium. It is characterized by including the irradiation means for irradiating.

In addition, the present invention provides a head for recording information on a recording medium, comprising: a reflecting surface reflecting incident light and a light transmitting portion for guiding light reflected by the reflecting surface to a position for recording information of the recording medium. Characterized in having a.

The information recording apparatus according to the present invention can solve the problem of thermal fluctuation because light is incident on the head from a position spaced from the arm by a predetermined distance, and the light incident on the head is irradiated to a position for recording information on the recording medium. At the same time, information can be recorded at high speed on the recording medium by high-speed seek.

Further, the head according to the present invention reflects the incident light and guides the reflected light to a position for recording the information of the recording medium, so that the heat assist can be efficiently performed.

1 is a diagram showing a case where the magnetic disk device according to the present embodiment is viewed from above.

FIG. 2 is a diagram showing an ideal light beam perpendicular to the light inlet on the side of the slider at each rotation angle of the swing arm shown in FIG. 1; FIG.

FIG. 3 is a diagram showing the configuration of a magnetic disk device for producing light rays shown in FIG. 2; FIG.

FIG. 4 is a diagram showing a deviation between the position of the laser light emitted from the LD and the position of the slider's optical axis reference (this optical axis reference corresponds to the light entrance port) at each rotation angle of the swing arm 20 shown in FIG. 3.

Fig. 5A is a diagram showing a diffraction image (when the slider rotation angle is 0 °) of the light entrance port when the size of the aperture of the lens is set to 0.5 mm in the X direction and 0.2 mm in the Y direction. .

Fig. 5B is a diagram showing a diffraction image (when the slider rotation angle is 8 °) of the light entrance port when the size of the aperture of the lens is set to 0.5 mm in the X direction and 0.2 mm in the Y direction.

Fig. 5C is a diagram showing the diffraction image (when the slider rotation angle is 16 °) of the light entrance port when the size of the aperture of the lens is set to 0.5 mm in the X direction and 0.2 mm in the Y direction.

6A is a diagram illustrating a case where a laser beam from LD is divided by a beam splitter, and the divided laser light is incident on each slider.

Fig. 6B is a diagram showing a case where the laser light from LD is enlarged by the magnifying lens and the laser light is incident on each slider.

FIG. 7 is a diagram showing an example in which a laser beam is incident on a slider of each platter by using a MEMS mirror of uniaxial scanning. FIG.

Fig. 8 is a diagram showing a magnetic disk device capable of realizing a capacity of 400 to 50 Gb / in ² in such an optical system.

Fig. 9A is a first diagram showing the configuration of a magnetic disk device in the case of scanning laser light in the X direction or the Y direction.

Fig. 9B is a second diagram showing the configuration of a magnetic disk device in the case of scanning laser light in the X direction or the Y direction.

10 is an explanatory diagram for explaining an optical unit for switching laser light by using a liquid crystal.

FIG. 11 shows an example in the case where a reflecting surface is included in a spherical aberration lens. FIG.

12 is a diagram showing the configuration of a head portion of a magnetic disk apparatus according to the present embodiment.

FIG. 13 is a view showing a detailed configuration of the head portion shown in FIG. 12; FIG.

FIG. 14 is a first explanatory diagram for explaining a manufacturing method of the head portion shown in FIGS. 12 and 13.

FIG. 15 is a second explanatory diagram for explaining a method for manufacturing the head portion shown in FIGS. 12 and 13.

Fig. 16 is a diagram showing the configuration of a head portion using a diffractive optical element.

FIG. 17 is a diagram showing a detailed configuration of the head portion shown in FIG. 16; FIG.

18 is an explanatory diagram for explaining a method for creating a head portion shown in FIGS. 16 and 17.

19 shows an overview of a magnetic disk device.

Fig. 20 is a diagram showing the configuration of a head called a short magnetic pole vertical recording head.

21 is an explanatory diagram for explaining the prior art;

Explanation of symbols for the main parts of the drawings

20: swing arm 30: center of rotation of the swing arm

40: magnetic disk 50: center of rotation of the magnetic disk

60: slider 70: spherical aberration lens

80: mirror 90: beam converter

100: semiconductor laser (LD) 101: beam splitter

102, 104, 108, 111, 140, 150, 160: spherical aberration lens

103: enlarged lens 105, 120: beam converter

106, 109: MEMS mirror 107: cylindrical lens

110: collimated lens 130: optical unit

130a, 130b, 130c: TN type liquid crystal 130d: polarization beam splitter

130e: cylindrical lens 200, 300: slider

210 and 310: light entrance holes 220 and 320: reflection mirrors

230, 330: magnetic head 230a, 330a: terminal pole head

230b, 330b: Magnetic head for regeneration 240, 340: Exit port

250, 360: clad 260, 370: core

350: diffractive optical element

EMBODIMENT OF THE INVENTION Below, the Example of the information recording apparatus which concerns on this invention is described in detail based on drawing. In addition, this invention is not limited by this Example.

Example

First, the characteristics of the magnetic disk device according to the present invention (in this embodiment, the magnetic disk device will be described as an example of the information recording device) will be described. An information recording apparatus according to the present invention includes a semiconductor laser (hereinafter referred to as LD) for outputting laser light for performing thermal assist, a head for recording and reproducing information on a magnetic recording medium and the magnetic recording medium. Is placed at a stationary position in the magnetic disk apparatus other than the swing arm on which the is mounted.

When the magnetic disk apparatus records information on the magnetic recording medium, the laser beam is emitted from the LD toward the light entrance port of the head (to be described later for the light entrance port of the head), and the light incident on the head is input. Is irradiated onto the magnetic recording medium to magnetically record information at the position irradiated with the laser light.

As described above, the magnetic disk apparatus according to the present invention arranges LD at a position other than the swing arm, emits a laser beam from the arranged position to the light entrance port of the head, and performs thermal assist during information recording. It is not necessary to provide the LD and the LD electrical wiring on the swing arm, and the problem of thermal fluctuation can be solved without damaging the advantages of the existing magnetic disk device, that is, high-speed recording and reproducing by high-speed seek.

The magnetic disk device according to the present embodiment will be described in detail below. 1 is a diagram showing a case where the magnetic disk device according to the present embodiment is viewed from above. In order to irradiate light from the stop position of the LD (not shown) to the light entrance port of the slider 60, the magnetic disk device preferably simply makes the laser light touch the side surface of the slider 60.

In addition, when the magnetic disk device injects light into the slider 60, the light incidence opening provided on the side surface of the slider 60 enters the light incidence opening at a constant angle at any rotation angle of the slider. It is also preferable in order to maintain the characteristic of the following optical system. Although various angles are conceivable for the angle of incidence of light to the slider 60, it is most preferable to inject perpendicularly to the side surface of the slider 60 in terms of space in the magnetic disk device, design of the optical system, and ease of manufacture of the slider.

However, only by irradiating the laser beam 60 from the LD to the slider 60, the condition that the laser beam is not perpendicular to the side of the slider 60 without interruption for each rotation angle of the swing arm 20 is determined. Can't keep up FIG. 2 is a diagram showing an ideal light beam that is incident perpendicularly to the light entrance port on the side of the slider at each rotation angle of the swing arm 20 shown in FIG. 1.

In addition, the light ray shown in FIG. 2 is 32 mm in the distance from the rotation center 30 of the swing arm to the light entrance port of the slider 60, and the rotation of the slider 60 is based on an actual magnetic disk apparatus. It is assumed that the radius from the rotation center 50 of the 40 rotates from 17 mm to 30 mm, and the disk circumference from the light entrance port of the vertical light beam when the slider 60 is at the innermost circumference. The distance toward the outside is set to 25 mm, the abscissa indicates the position of the light beam in the X direction as 0 mm, the position in the X-axis direction in FIG. 1 perpendicular to the light beam is calculated, and the required light beam is calculated. . In addition, the disk radius is assumed to be 35 mm, and, of course, the position outside the disk. In this invention, the light ray shown in FIG. 2 is produced using the aberration of an optical system.

Here, the method of producing the light ray shown in FIG. 2 using the aberration of an optical system is demonstrated. Specifically, in the present embodiment, spherical aberration of the optical system is generated when generating the light beam shown in FIG. The position of the slider 60 at the innermost circumference of the swing arm 20 is regarded as the optical axis center of the optical system, and the farther the slider 60 is from the rotation center 50 of the magnetic disk, the closer the ray is to the optical axis center. Use aberrations

FIG. 3 is a diagram showing the configuration of a magnetic disk device for producing light rays shown in FIG. As shown in the figure, the magnetic disk apparatus has a swing arm 20, a slider 60, a spherical aberration lens 70, a mirror 80, a beam converter 90, and an LD 100. As shown in FIG. 3, the laser light emitted from the LD 100 is once compressed by the beam converter 90 composed of a collimated lens and a cylindrical lens, and is incident on the mirror 80. The laser light is reflected by the mirror 80 and then irradiated to the light entrance port of the slider 60 through the spherical aberration lens 70.

Here, the design value of the spherical aberration lens 70 for generating the spherical aberration of the optical system is

[Equation 1]

…(1)

… (One)

but,

r = 10.0 mm

A = 0.42

C ₁ = -0.2913973 × 10 ^-15

C ₂ = -0.8704928 × 10 ^-13

C ₃ = -0.3561886 × 10 ^-11

C ₄ = -0.1349156 × 10 ^-10

It can be represented by the formula of a non-spherical lens as shown in FIG. In addition, the glass material is BK-7 (refractive index is 1.5222). The wavelength of the laser light output from the LD 100 is set to 660 nm (the same wavelength as the laser light output from the red semiconductor laser for DVD <Digital Versatile Disk>). In this formula (1), Z represents the height of the spherical aberration lens, and variables corresponding to the X and Y axes of the spherical aberration lens are input to x and y. In addition, A, C ₁ ~C ₄ are constants related to the aspheric lens (if the lens thickness to the 1O㎜) and, r represents the radius of the aspherical lens.

4 shows the position of the laser light emitted from the LD 100 at each rotation angle of the swing arm 20 shown in FIG. 3 and the position of the optical axis reference of the slider 60 (this optical axis reference corresponds to the light incidence opening). It is a figure which shows the misalignment of. Here, the slider rotation angle is defined as the angle toward the outer circumference, with the position of the swing arm at the innermost circumference being 0 °. As shown in the drawing, in the case of using the spherical aberration lens 70 for generating the spherical aberration of the optical system, it can be seen that the laser light exists at an almost ideal position with respect to the light inlet of the slider 60. . On the other hand, when a non-spherical aberration lens without spherical aberration is used, as shown in Fig. 4, since the laser light is shifted by about 2 mm from the light entrance port, only a small amount of light can be secured and the slider (in the innermost circumference) Light efficiency other than the position of 60) becomes 0%.

In addition, since the spherical aberration lens 70 shown in FIG. 3 uses only one side of a lens, when producing the spherical aberration lens 70 actually, it can be created by a mold and it is also preferable at the point of space saving. In addition, there is an example in which not only an aspherical lens but also a combination of spherical lenses or one spherical lens is available.

Here, at each rotation angle of the swing arm 20, the effect of light utilization efficiency and the like regarding the vertical incidence of the laser light into the light incidence opening of the slider 60 is verified. When the laser beam was irradiated on the entire surface of the spherical aberration lens 70, it was verified as shown below that the light utilization efficiency for the light incidence opening of the slider 60 was accepted at a high efficiency of 15%.

The calculation shows how much the laser beam transmitted through the spherical aberration lens 70 is incident on the light entrance port of the slider 60 at each rotation angle of the swing arm 20. Moreover, the magnitude | size of the circumferential direction of the light incident opening of the slider 60 is 100 micrometers, and the magnitude | size of the vertical direction is 100 micrometers.

The spherical aberration lens is virtually shaped as the maximum allowable aperture, which is equal to or smaller than the size (100 μm in the circumferential direction and the vertical direction) of the light entrance port provided in the slider 60 at the position of each rotation angle of the swing arm 20. Set to the front of (70). Hereinafter, this opening is referred to as the opening of the spherical aberration lens 70.

The opening of the spherical aberration lens 70 moves corresponding to each position of the rotational angle of the slider 60. 5A, 5B and 5C show diffraction images of the light condensing surface when the size of the aperture of the spherical aberration lens 70 is set to 0.5 mm in the X direction and 0.2 mm in the Y direction (slider rotation angle is 0 °, 8 degrees and 16 degrees). Here, the light condensing surface is a surface that receives a beam in the slider.

As shown in Figs. 5A, 5B and 5C, it can be seen that each diffraction image has a beam size of 80 占 퐉 at each rotation angle of the slider 60. From this, when the laser beam is incident on the spherical aberration lens 70 shown in FIG. 3 by scanning the laser light in a direction parallel to the surface of the recording medium, the opening of the laser beam entering the spherical aberration lens 70 in the X direction. If it is set to 0.5 mm and 0.2 mm in the Y direction, it can be seen that the diffraction image has a beam size of 80 µm for any slider position. Here, strictly speaking, the beam size becomes smaller as the rotation angle becomes larger, i.e., closer to the spherical aberration lens, because the F number of the beam becomes smaller. Therefore, it is preferable to set the F number so that the size of the beam related to the light utilization efficiency becomes the desired beam diameter at the innermost circumference where the disk rotation angle is 0 °. This is because if the beam diameter at this time is less than the size of the entrance hole, the beam diameter is lower at any rotation angle and there is no loss of light amount.

 Further, when the laser beam is irradiated to the entire surface of the spherical aberration lens 70 with the aperture of the spherical aberration lens 70 as a whole lens, the light entrance port (100 μm) at each rotational position of the slider 60 is used. When the intensity ratio of the light entering each corner was calculated, it was found that at each position of the slider 60, the light utilization efficiency was accepted at 15%. In addition, depending on the design method of this spherical aberration lens 70, this light utilization efficiency can be improved to 30%.

In addition, although the position of the slider 60 in the innermost periphery of the swing arm 20 was made into the optical axis center of the spherical aberration of an optical system here, it is not limited to this, The slider 60 in the outermost periphery of the swing arm 20 is not limited to this. Position may be regarded as the optical axis center of spherical aberration. In this case, it is also conceivable to use a spherical aberration lens that generates an aberration farther from the optical axis center as the slider 60 moves inward.

By the way, since the magnetic disk apparatus has a plurality of magnetic disks (platters), and the magnetic recording is performed on the front surface or the rear surface of each magnetic disk, it is necessary to make the laser light touch each surface of the magnetic disk for performing magnetic recording. There is.

Regarding the irradiation of the laser light, when the laser intensity is high, a plurality of platters, for example, two platters and four recording surfaces, can irradiate the laser light onto each surface simultaneously without switching the optical path. FIG. 6A is a diagram showing a case where the laser light from the LD 100 is divided by the beam splitter 101, and the divided laser light is incident on each slider 60. FIG. 6B is a view from the LD 100. FIG. It is a figure which shows the case where a laser beam is magnified with the magnification lens 103, and a laser beam is made to enter into each slider 60. As shown in FIG. The spherical aberration lenses 102 and 104 shown in the figure have lenses having the same number of spherical aberration faces as the sliders (in the figure, lenses having four spherical aberration faces are included).

In addition, in FIGS. 6A and 6B, it is also effective to shield the laser light by a mechanical shutter so that the laser light is not irradiated on the slider (the slider which does not perform magnetic recording) that does not need to enter the laser light. Alternatively, a plurality of LDs may be used for each platter surface.

6A and 6B, in order to increase the number of beam lights by the number of front and back surfaces of the platter, the spherical aberration lens 102, 104 has a spherical aberration lens whose curvature of each lens is shown in FIG. 3 in the thickness direction of the platter. Although it becomes the shape which has the thing of the same curvature as the curvature of 70, this can be manufactured at low cost by the existing mold technique.

6A and 6B, the optical paths are switched to movable mirrors such as MEMS (Micro Electro Mechanical System) mirrors and galvano mirrors without irradiating a plurality of platters at the same time. The laser beam may be touched.

FIG. 7 is a diagram showing an example in which a laser beam is incident on a slider of each platter by using a MEMS mirror for uniaxial scanning. As shown in FIG. 7, the laser light output by the LD 100 is focused on the MEMS mirror 106 by the beam converter 105. After the laser light is reflected by the MEMS mirror 106, the laser beam passes through the cylindrical lens 107 and is incident on the spherical aberration lens 108.

Here, the cylindrical lens 107 is a lens for converting only the y direction of the transmitted laser light into parallel light. In addition, in this embodiment, the cylindrical lens 107 is disposed 10 mm away from the MEMS mirror 106, and the center thickness is 4 mm and the curvature is set to 5 mm.

By using the cylindrical lens 107, even if the optical path of the laser light is switched to the MEMS mirror 106, the laser light in the y-direction is parallel light parallel to the platter direction, and the light entrance port of the slider corresponding to each platter is used. The laser beam can be incident on the laser beam accurately. In addition, the spherical aberration lens 108 has a shape having a plurality of the same curvature as the spherical aberration lens 70 shown in FIG. 3 in the thickness direction of the platter.

Next, the light amount (laser power) used in the present embodiment will be described. In the present invention, a practical magnetic disk device is the main focus, and a capacity of about 400 to 50 Gb / in ² is targeted. Since this capacity is four to five times the capacity of the mainstream magnetic disk capacity, it is a sufficiently attractive value.

Therefore, the effect of thermal assist can be obtained at a much lower temperature, for example, about 10 ° C., than raising the temperature to about 200 ° C. in a fine beam spot of several 10 mm, as in the case of ¹ Tb / in ² . Therefore, since the light beam spot can also obtain a temperature of about 100 [deg.] C. at about 1 [mu] m, the head portion for irradiating light to the recording medium becomes easy.

Irradiation conditions for verifying the laser power required for recording information on such a magnetic recording medium are 42 m / sec for the magnetic disk, 1 탆 in the radial direction and the beam size for the thermal assist. The distance from the center of the light spot to the terminal pole of the terminal pole head was 2 m.

Under this irradiation condition, by heating the temperature at a position on the magnetic recording medium corresponding to the terminal electrode to 100 캜, a sufficient thermal assist effect can be obtained at a capacity of 400 to 50 Gb / in ² . In order to obtain this thermal assist effect, it turned out by calculation that it was necessary to set the ambient temperature to 20 degreeC, and to make the temperature of the laser beam irradiation position of the front side which a magnetic field irradiate from a head be 140 degreeC. At the place where this temperature was irradiated, once, temperature rises further and thereafter, it goes down and becomes 100 degreeC in the position of 2 micrometers.

When the thermal calculation is performed under the above conditions, the beam size of the laser beam to be used is 1 占 퐉, and the recording medium increases the temperature at the laser irradiation position of the head to 140 ° C in a TbFeCo-based thin film vertical recording medium using a substrate as glass. In order to make it work, 5 kW laser power is required. In the standard LD (wavelength of 660 nm) used in DVD-RW, etc., output of about 35 kHz can be output from direct current, and even if the entire LD light is irradiated with the spherical aberration lens, the spherical aberration lens is released. Since the total efficiency to the subsequent light entrance hole is 20%, even if the light efficiency of the head portion is taken into consideration, it is sufficient output and a temperature increase of 140 ° C is possible. 8 is a diagram showing a magnetic disk device capable of realizing a capacity of 400 to 500 Gb / in ² in such an optical system. The radius of the swing arm of the magnetic disk device shown in FIG. 8 is 34.8 mm. Here, the MEMS only scans one axis for switching the medium plane.

In addition, when it is desired to further secure the amount of light incident on the slider, the laser beam can be scanned in the X direction or the Y direction by rotating the MEMS mirror or the like. 9A and 9B are views showing the configuration of a magnetic disk device in the case of scanning laser light in the X direction or the Y direction.

As shown in the figure, the laser light output from the LD 100 is reflected by the MEMS mirror 109, and the laser light reflected by the MEMS mirror 109 passes through the collimated lens 110 and is parallel light. Is converted to. The laser light converted into parallel light passes through the spherical aberration lens 111 and is incident on the light entrance port of the slider 60. At this time, if the size of the opening of the spherical aberration lens is set to 0.5 mm in the X direction and 0.2 mm in the Y direction, the diffraction image as shown in Figs. 5A to 5C is collected in the slider. Obtained in terms of

In this embodiment, the MEMS mirror 109 also has a structure that rotates even on a surface parallel to the medium surface, and the rotation thereof is controlled by a controller (not shown). The controller changes the rotation angle of the MEMS mirror 109 so that the laser light reflected by the MEMS mirror 109 is incident on the light entrance port of the slider 60. The controller maintains a table indicating a relationship between a position at which information on the magnetic disk is recorded and a rotation angle of the MEMS mirror corresponding to the position, and the table is used to control the rotation of the MEMS mirror 109.

In addition, the controller detects the light amount of the laser light reflected from the mirror provided inside the slider 60, and corrects the rotation angle of the MEMS mirror 109 so that the light amount of the reflected laser light is maximized.

By the way, the laser beam can be switched by using the liquid crystal. 10 is an explanatory diagram for explaining an optical unit 130 for switching laser light by using liquid crystal. As shown in the figure, the laser light of P polarization (the direction of linear polarization of LD is Y-direction) emitted from the LD 100 is narrowed by the beam converter 120 and then enters the optical unit 130. The optical unit 130 switches the optical path of the laser light so that the laser light is incident on the light entrance port of the desired slider.

The optical unit 130 includes TN type liquid crystals 130a, 130b, and 130c, a polarizing beam splitter 130d, and a cylindrical lens 130e. The TN type liquid crystals 130a, 130b, and 130c are liquid crystals which change the polarization direction of the laser light. Specifically, when the TN-type liquid crystal is off, the P-polarized laser light is converted into the S-polarized laser light, and when it is on, the P-polarized light is changed as it is.

The polarizing beam splitter 130d is a beam splitter that transmits P-polarized laser light and reflects the S-polarized laser light, and the cylindrical lens 130e is a lens that converts only the y-direction of the transmitted laser light into parallel light. . The optical unit 130 may switch the laser light incident on each slider by switching the TN type liquid crystals 130a, 130b, and 130c on and off, respectively.

For example, in FIG. 10, when the TN type liquid crystal 130a is turned on and the TN type liquid crystal 130b is turned off, the laser light 2 is output from the optical unit 130, and the laser light 2, 3) and the laser light 4 are not output. Thus, by turning on and off the TN type liquid crystals 130a, 130b, and 130c, each laser beam 1 to 4 can be switched non-mechanically.

In addition, the above-described spherical aberration lens may include a reflecting surface. FIG. 11 is a diagram illustrating an example in which a reflective surface is included in a spherical aberration lens. FIG. As shown in the figure, the spherical aberration lenses 150 and 160 each include reflecting surfaces 150a and 160a, and each reflecting surface plays the same role as the mirror 80 shown in FIG. There is no need to provide a mirror in the apparatus, and the miniaturization and low cost of the magnetic disk apparatus can be realized. In addition, in this embodiment, when generating aberration, spherical aberration lens was used, but aberration can be generated even if a diffractive optical element is used instead of the spherical aberration lens.

Next, the configuration of the head portion of the magnetic disk apparatus according to the present embodiment will be described. 12 is a diagram showing the configuration of a head portion of the magnetic disk apparatus according to the present embodiment. As shown in the figure, this head portion is composed of a slider 200 and a magnetic head 230, the slider 200 has a light entrance port 210 and a reflection mirror 220, the magnetic head 230 is It has a light exit port 240. The laser light irradiated to this head part is incident in the head from the light entrance port 210, and is reflected by the reflection mirror 220. As shown in FIG. And the laser beam reflected by the reflection mirror 220 is designed so that a beam diameter may be set to 80 micrometers. Then, it exits from the exit port 240 and performs the column assist at the time of information recording.

The laser light reflected by the reflection mirror 220 passes through the core Ta ₂ O ₅ 260, and thereafter propagates through the cores in both clads and is irradiated from the exit port 240. do.

It is a figure which shows the detailed structure of the head part shown in FIG. As shown in the figure, the magnetic head 230 has a terminal pole head 230a and a reproducing magnetic head 230b. The terminal pole head 230a is a head for generating magnetic flux to record information on the magnetic disk, and the reproducing magnetic head 230b is a head for reproducing information recorded on the magnetic disk. Here, the magnetic head portion is opposite in direction to the magnetic head shown in Fig. 20, that is, the side closer to the slider is the main magnetic pole. This is because it is desirable to bring the light irradiation position and the main magnetic pole position as close as possible. In addition, although the reproduction magnetic head is provided on the left side rather than the reflection mirror, it is not necessary to make such an installation.

In addition, the laser light reflected by the reflection mirror 220 passes through the core Ta ₂ O ₅ 260 between the cladding (SiO ₂ ) 250 and is irradiated from the exit port 240. Here, the refractive index of the core is higher than that of the clad.

However, each dimension shown in FIG.

W ₁ = 100 μm

W ₂ = 1 μm

W ₃ = 1 μm

W ₄ = 1 μm

d = 1 탆.

Next, the manufacturing method of the head part shown in FIG. 12 and FIG. 13 is demonstrated. 14 and 15 are explanatory diagrams for explaining the manufacturing method of the head portion shown in FIGS. 12 and 13. As shown in the drawing, first, an Si substrate (crystal directions <1, 1, 1>, etc.) is bonded to an AlTiC substrate (slider material), and the bonded substrate is polished to a desired thickness. As described above, when the regenerated magnetic head is first formed, the regenerated magnetic head is formed on an AlTiC substrate (slider material), and the Si substrate is attached to this surface.

Subsequently, in order to form the reflection mirror 220 shown in FIG. 13, it is patterned with a photoresist and wet etching for forming inclined surfaces is performed. When the inclined surface is produced in this way, a high refractive index film through which light passes is formed. Next, in order to flatten the surface, CMP (Chemical Mechanical Polishing) is performed. In addition, it is possible to omit the CMP process after forming a high refractive index film. Alternatively, as shown in FIG. 14, a reflective film is formed on a glass substrate or the like so as to form an optical head for an optical disk on an AlTiC substrate (slider material), laminated in a multi-layered shape, and then cut into an oblique cut to form a matrix. It is also possible to attach a mirror array.

Next, in FIG. 15, a new manufacturing method is shown. In FIG. 15, the figure in one is shown. The clad SiO ₂ is partially formed on the substrate having the completed reflective surface of (1) except for the portion through which light from the reflective mirror passes ((2)). This can be easily realized by patterning the resist. After that, planarization is performed by performing CMP. After depositing the core Ta ₂ O ₅ ((3)), etching the core exit portion (the portion corresponding to the exit port 240 shown in FIG. 12) ((4)), forming the clad SiO ₂ . ((5)). Then, through the CMP, the terminal electrode head 230a is produced by a normal magnetic head manufacturing process.

By the way, by using the diffractive optical element in the head part, a laser beam can also be made to enter a core. It is a figure which shows the structure of the head part using a diffraction optical element. As shown in the figure, this head portion is composed of a slider 300 and a magnetic head 330, which has a light entrance port 310, a reflection mirror 320, and a diffractive optical element 350. . The laser light irradiated to this head part is incident in the head from the light entrance port 310, and is reflected by the reflection mirror 320. As shown in FIG. The laser light reflected by the reflection mirror 320 is not totally reflected by the diffractive optical element 350, but is incident on the core, and the laser light incident on the core is emitted from the exit port 340 to record information. A column assist of the city is performed.

17 is a diagram illustrating a detailed configuration of the head portion shown in FIG. 16. As shown in the figure, the magnetic head 330 has a terminal pole head 330a and a reproducing magnetic head 330b. Further, the laser light reflected by the reflection mirror 320 is incident on the core 370 between the clads 360 by the diffractive optical element 350 and irradiated from the exit port 340.

However, each dimension shown in FIG.

T ₁ = 100 μm

T ₂ = 1 μm

T ₃ = 1 μm

d = 1 탆.

Next, the manufacturing method of the head part shown in FIG. 16 and FIG. 17 is demonstrated. It is explanatory drawing for demonstrating the manufacturing method of the head part shown in FIG. 16 and FIG. As shown in the figure, first, a Si substrate is bonded to an AlTiC substrate, and the bonded substrate is polished to a desired thickness. Of course, when the regenerated magnetic head is first formed, the regenerated magnetic head is formed on an AlTiC substrate (slider material), and the Si substrate is attached to this surface.

Subsequently, after the reflection mirror 320 is fabricated, the diffractive optical element 350 is manufactured by etching, and after depositing Ta ₂ O ₅ for the core, the core exit portion (340) corresponding to the exit port 340 shown in FIG. Part) is etched. Then, a clad SiO ₂ is formed and a recording magnetic head is produced by a normal magnetic head manufacturing process via CMP.

As described above, the head portion according to the present invention is produced at the same time as the head used in the conventional magnetic disk apparatus by the wafer process and can be mounted at the same time as the magnetic head for recording and reproduction. Can be suppressed.

As described above, in the information recording apparatus according to the present embodiment, the LD 100 arranged at a predetermined distance from the swing arm 20 outputs laser light, and the laser light output from the LD 100 is a beam. Via the converter 90 and the mirror 80, the spherical aberration lens 70 that generates spherical aberration is irradiated. Then, the laser beam transmitted through the spherical aberration lens is incident on the light incidence opening of the slider 60 at a predetermined angle (for example, vertical), and performs thermal assist during information recording, thereby increasing the recording density of the recording medium. This solves the problem of thermal assist.

In addition, the information recording apparatus according to the present embodiment arranges the LD 100 or the like at a position other than the swing arm 20 and performs column assist during information recording, so that the advantages of the magnetic disk apparatus are not lost. High-speed recording and high-speed reproduction of information by high-speed seek of the swing arm 20 can be performed.

In addition, in FIG. 3, between the mirror 80 and the spherical aberration lens 70, it is shown in Japanese Patent Application No. TEN 1057 patent application, and Japanese Patent Application No. TEN 1010 patent application 260281. As described above, an optical element that makes the intensity distribution of light constant may be disposed. By transmitting the laser beam through the optical element and irradiating the transmitted laser beam to the entire surface of the spherical aberration lens 70, the laser beam can be incident precisely to the light entrance port of the slider 60.

In addition, in the present embodiment, a magnetic disk device having a terminal electrode head has been described, but the present invention can be applied to a magnetic disk device having an in-plane recording head or a phase change type optical disk. .

As described above, the information recording apparatus according to the present invention is useful for a magnetic disk apparatus or the like which needs to record information in a high density on the recording medium and to prevent the problem of thermal fluctuations occurring in the recording medium.

Claims (22)

An information recording apparatus which controls an arm provided with a head for recording information on a recording medium to record information on the recording medium. A light incidence means arranged at a stop position other than the arm to rotate, for injecting light into the head; And an irradiation means for irradiating the light incident on the head by the light incidence means to a position where the information on the recording medium is recorded. The method of claim 1, The recording medium is a magnetic recording medium, and the head records information by magnetism at a position of the magnetic recording medium irradiated with light by the irradiation means. The method according to claim 1 or 2, And the light incidence means injects light into the head at a constant incidence angle. The method of claim 3, wherein And the light incidence means injects light perpendicular to the head. The method according to claim 1 or 2, And an aberration generating means for generating an aberration, wherein the light incidence means transmits the aberration generating means to light and causes the transmitted light to enter the head. The method of claim 5, wherein And an aberration generated by said aberration generating means is spherical aberration. The method of claim 5, wherein The aberration generating means is a spherical aberration lens that generates spherical aberration, and the aspherical coefficient A of the spherical aberration lens is 0.4 or more and 0.6 or less. The method of claim 5, wherein And the aberration generating means is constituted by a plurality of spherical aberration lenses for generating spherical aberration. The method of claim 7, wherein And the lens for generating the spherical aberration is an aspheric lens. The method of claim 7, wherein And the lens for generating the spherical aberration has only one side of the lens shape. The method of claim 8, And the aberration generating means is constituted by an aspherical aberration lens having the same number of surfaces as the recording surface of the recording medium. The method of claim 5, wherein And the light incidence means irradiates the entire surface of the aberration generating means, transmits the irradiated light through the aberration generating means, and enters the transmitted light into the head. The method of claim 1, And an optical path changing means for changing an optical path of light incident on the head from the light incidence means in accordance with the position of the head. The method of claim 13, And the optical path changing means detects the light amount of light reflected from the reflecting surface provided in the head, and changes the optical path of the light incident on the head from the light incidence means so as to maximize the light amount. . The method of claim 13, And the optical path changing means comprises polarization direction changing means for changing a polarization direction of light incident on the head from the light incidence means and light shielding means for shielding light in a predetermined polarization direction. The method of claim 1, And parallel light converting means for converting light incident on the head from the light incidence means into parallel light parallel to a recording surface of the recording medium. The method of claim 1, And light blocking means for blocking light other than the light incident on the head from the light incidence means. The method of claim 1, And the light incidence means injects light into the head so that when the head is located at the innermost circumference of the recording medium, the size of light incident on the head becomes a predetermined size. Information recording device. A head for recording information on a recording medium, A reflecting surface reflecting incident light, And a light transmitting portion for guiding the light reflected by the reflecting surface to a position for recording the information of the recording medium. The method of claim 19, The refractive index of the said light transmitting part is higher than the refractive index of the material which contact | connects the said light transmitting part, The head characterized by the above-mentioned. The method of claim 19, And a diffraction grating for causing the light reflected on the reflective surface to enter the light transmitting portion. The method of claim 19, And a distance from the position where the light is transmitted to the light transmitting portion to the recording medium is larger than the distance from the bottom of the head to the recording medium.

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