JP2007073112A - Optical head and optical device for optical recording/reproduction - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical head capable of stably floating the floating slider, by specifying weight of an optical element and thickness of the floating slider to set the deflexion of a floating slider within tolerance, and an optical device for optical recording/reproduction, equipped with the optical head. <P>SOLUTION: An optical head 1 is equipped with a floating slider 11, which floats while a designated space is held to a recording medium 40 for running relatively on the recording medium when information is recorded to the recording medium 40 and/or the information is reproduced from the information recording medium 40; and an optical element 10 bonded with the above floating slider 11, condensing incidence light at a designated position. And weight w(mg weight) of the above optical element 10 and average thickness h(mm) of the floating slider 11 satisfy a conditional expression w/h<SP>3</SP>≤50,000. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention includes an optical element that includes an optical element and a flying slider, and is used when information is recorded on and / or reproduced from a recording medium using near-field optics, and the optical head. The present invention relates to an optical recording / reproducing optical apparatus for recording and / or reproducing information.

  In order to achieve higher recording density of recording media such as optical discs, it is necessary to collect light to the diffraction limit by using an optical element having a numerical aperture (NA) as high as possible to obtain a minute light spot. It is. However, in the conventional optical lens, since the NA has already approached 1.0, the reduction in the diameter of the light spot has reached its limit. Therefore, in recent years, a method for increasing the effective NA of light using a solid immersion lens (SIL) or a solid immersion mirror (SIM) made of a high refractive index material has been proposed. .

  Light generated from the SIL or SIM and used when recording information on the recording medium and / or reproducing from the recording medium is referred to as near-field light (evanescent light). Usually, light includes propagating light and non-propagating light, and near-field light belongs to the latter. Near-field light is non-propagating light that oozes slightly from the surface of the minute substance to the air side. The amount of oozing is not only the wavelength of the incident light but also the size of the optical element such as a lens and the optical element. It also depends on the optical properties of the material. Therefore, for example, by limiting the size of the optical element to be smaller than the wavelength of the incident light, it is possible to record and / or reproduce information in an area smaller than the wavelength of the incident light.

  However, since near-field light is localized light generated in the vicinity of an object, a recording / reproducing head is used when information is recorded on and / or reproduced from a recording medium using the near-field light. It is necessary to make the distance between the recording medium and the recording medium close to, for example, 1/10 or less (about 10 (nm) to 50 (nm)) of the wavelength used.

For example, Patent Document 1 discloses a technique relating to an optical head slider in which an optical element and a slider member are combined and optically integrated. According to the technique according to Patent Document 1, since the NA of the optical system including the optical element and the slider member is 1 or more, a slider that can realize a minute light spot and can be easily manufactured can be provided. Patent Document 2 discloses a technique for stabilizing the distance between the recording medium and the slider in the range of several nanometers to several tens of nanometers by providing a groove for controlling the air flow generated by the rotation of the recording medium. ing.
JP 2000-113484 A JP 2001-34979 A

  However, in the optical head slider according to Patent Document 1 and the optical head according to Patent Document 2, there is no description regarding the weight of the optical element, the thickness of the slider member, etc., and the deflection of the slider member due to the weight of the optical element is not described. The impact is not considered.

  The present invention has been made in view of such a situation, and by defining the weight of the optical element and the thickness of the flying slider, the deflection amount of the flying slider can be within an allowable value, thereby It is an object of the present invention to provide an optical head capable of stably flying a flying slider, and an optical recording / reproducing optical apparatus including the optical head.

The invention according to claim 1 is an optical head, and when the information is recorded on the recording medium and / or the information is reproduced from the recording medium, the recording head floats in a state of maintaining a predetermined distance from the recording medium. A floating slider that travels relatively on the medium; and an optical element that is fixed to the floating slider and collects incident light at a predetermined position. The weight of the optical element is w (mg weight), Conditional expression w / h ³ ≦ 50000 is satisfied, where h (mm) is the average thickness of the flying slider.

  According to this configuration, in an optical head including a flying slider and an optical element, a condition is imposed between the weight of the optical element and the average thickness of the flying slider. Usually, the amount of deflection of the flying slider can be kept small when the weight of the optical element is light and when the average thickness of the flying slider is thick. By imposing this in the form of a specific conditional expression, the amount of deflection can be kept small, and problems such as contact between the flying slider and the recording medium in the optical head can be prevented, and stable flying can be realized.

  Here, the average thickness of the flying slider is the average thickness of only the portion that determines the amount of deflection in the flying slider. That is, it is not necessary to consider the thickness of the portion that does not affect the deflection of the flying slider. Further, the magnitude of gravity acting on an object having a certain mass is weight, and for example, the magnitude (weight) of gravity acting on an object having mass A (mg) is A (mg weight).

  The invention according to claim 2 is the optical head according to claim 1, wherein the weight w of the optical element is 0.2 (mg weight) or more and 40 (mg weight) or less.

  According to this configuration, since the weight w of the optical element is 0.2 (mg weight) or more, for example, a size that does not cause difficulty in handling when the optical element and the flying slider are fixed is secured. Can do. In addition, since the weight w of the optical element is suppressed to 40 (mg weight) or less, the width and thickness of the flying slider that supports the optical element can be reduced.

  The invention according to claim 3 is the optical head according to claim 1 or 2, wherein an average thickness h of the flying slider is 0.01 (mm) or more and 0.6 (mm) or less. Features.

  According to this configuration, since the average thickness h of the flying slider is 0.01 (mm) or more, handling is not difficult, and damage during handling can be prevented. Further, since the average thickness h of the flying slider is suppressed to 0.6 (mm) or less, the thickness of the optical element fixed to the flying slider can be increased correspondingly, and the necessary thickness can be ensured.

  A fourth aspect of the present invention is the optical head according to any one of the first to third aspects, wherein the optical element is made of a material having a transmittance with respect to the incident light of 50% or more. .

  According to this configuration, since the transmittance of the optical element is 50% or more, the amount of light necessary for recording can be reduced, and the heat generated by the optical element absorbing light can be kept small. In addition, the rotational speed of the recording medium can be kept low to such an extent that it can be rotated by the bearing mechanism. Furthermore, since the decrease in the amount of light collected at the condensing point can be suppressed to a small level, the decrease in the amount of near-field light that oozes out from the condensing point can also be suppressed to a small level.

  A fifth aspect of the present invention is the optical head according to any one of the first to fourth aspects, wherein the flying slider is made of a material having a transmittance of 50% or more for the incident light. .

  According to this configuration, since the transmittance of the flying slider is 50% or more, the amount of light necessary for recording can be reduced, and the heat generated by the flying slider absorbing light can be kept small. In addition, the rotational speed of the recording medium can be kept low to such an extent that it can be rotated by the bearing mechanism. Furthermore, since the decrease in the amount of light collected at the condensing point can be suppressed to a small level, the decrease in the amount of near-field light that oozes out from the condensing point can also be suppressed to a small level.

  A sixth aspect of the present invention is the optical head according to any one of the first to fifth aspects, wherein the optical element is a refracting surface, a reflecting surface, or a diffraction for condensing the incident light at a predetermined position. It has at least any one of the surfaces.

  According to this configuration, since the optical element has at least one of a refracting surface, a reflecting surface, and a diffractive surface, incident light can be effectively condensed at a predetermined position.

The invention according to claim 7 is an optical head having a portion that does not contribute to flying on the surface facing the recording medium, and when recording information on the recording medium and / or reproducing information from the recording medium, A flying slider that floats while maintaining a predetermined distance from the recording medium and travels relatively on the recording medium; and an optical element that is fixed to the flying slider and focuses incident light at a predetermined position. Provided that the weight of the optical element is w (mg weight) and the average thickness of the flying slider is h (mm), so that the conditional expression w / h ³ ≦ 50000 is satisfied.

  According to this configuration, in an optical head including a flying slider and an optical element, a condition is imposed between the weight of the optical element and the average thickness of the flying slider. Usually, the amount of deflection of the flying slider can be kept small when the weight of the optical element is light and when the average thickness of the flying slider is thick. By imposing this in the form of a specific conditional expression, the amount of deflection can be kept small, and problems such as contact between the flying slider and the recording medium in the optical head can be prevented, and stable flying can be realized.

  Here, the portion that does not contribute to flying is a surface of the flying slider that does not have an uneven pattern (floating structure) or the like provided in a normal flying slider. The average thickness of the flying slider is the average thickness of only the portion that determines the amount of deflection in the flying slider. That is, it is not necessary to consider the thickness of the portion that does not affect the deflection of the flying slider. Further, the magnitude of gravity acting on an object having a certain mass is weight, and for example, the magnitude (weight) of gravity acting on an object having mass A (mg) is A (mg weight).

  The invention according to claim 8 is the optical head according to claim 7, wherein the weight w of the optical element is 0.2 (mg weight) or more and 40 (mg weight) or less.

  According to this configuration, the condensing position of incident light can be brought close to the recording medium. Further, since the weight w of the optical element is 0.2 (mg weight) or more, for example, it is possible to ensure a size that does not cause difficulty in handling when the optical element and the floating slider are fixed. Furthermore, since the weight w of the optical element is suppressed to 40 (mg weight) or less, the width and thickness of the flying slider that supports the optical element can be reduced.

  The invention according to claim 9 is the optical head according to claim 7 or 8, wherein an average thickness h of the flying slider is 0.01 (mm) or more and 0.6 (mm) or less. Features.

  According to this configuration, the condensing position of incident light can be brought close to the recording medium. Further, since the average thickness h of the flying slider is 0.01 (mm) or more, handling is not difficult and damage during handling can be prevented. Furthermore, since the average thickness h of the flying slider is suppressed to 0.6 (mm) or less, the thickness of the optical element fixed to the flying slider can be increased correspondingly, and the necessary thickness can be secured.

  A tenth aspect of the present invention is the optical head according to any one of the seventh to ninth aspects, wherein the optical element is made of a material having a transmittance with respect to the incident light of 50% or more. .

  According to this configuration, since the transmittance of the optical element is 50% or more, the amount of light necessary for recording can be reduced, and the heat generated by the optical element absorbing light can be kept small. In addition, the rotational speed of the recording medium can be kept low to such an extent that it can be rotated by the bearing mechanism. Furthermore, since the decrease in the amount of light collected at the condensing point can be suppressed to a small level, the decrease in the amount of near-field light that oozes out from the condensing point can also be suppressed to a small level.

  An eleventh aspect of the invention is the optical head according to any one of the seventh to tenth aspects, wherein the flying slider is made of a material having a transmittance of 50% or more for the incident light. .

  According to this configuration, since the transmittance of the flying slider is 50% or more, the amount of light necessary for recording can be reduced, and the heat generated by the flying slider absorbing light can be kept small. In addition, the rotational speed of the recording medium can be kept low to such an extent that it can be rotated by the bearing mechanism. Furthermore, since the decrease in the amount of light collected at the condensing point can be suppressed to a small level, the decrease in the amount of near-field light that oozes out from the condensing point can also be suppressed to a small level.

  A twelfth aspect of the present invention is the optical head according to any one of the seventh to eleventh aspects, wherein the optical element is a refracting surface, a reflecting surface, or a diffraction for condensing the incident light at a predetermined position. It has one of the surfaces.

  According to this configuration, since the optical element has at least one of a refracting surface, a reflecting surface, and a diffractive surface, incident light can be effectively condensed at a predetermined position.

  The invention according to claim 13 is an optical head, and when the information is recorded on the recording medium and / or the information is reproduced from the recording medium, the optical head relatively travels on the recording medium while maintaining a predetermined flying height. And an optical element that is fixed to the flying slider and collects incident light at a predetermined position, wherein the deflection amount of the flying slider is smaller than the flying height.

  According to this configuration, since the deflection amount of the flying slider is smaller than the flying height, when the information is recorded on the recording medium and / or the information is reproduced from the recording medium, the flying slider comes into contact with the recording medium. Can prevent.

  The invention according to claim 14 is an optical apparatus for optical recording / reproducing, wherein the light source emits laser light having a predetermined wavelength, and the laser light emitted from the light source is condensed at a predetermined position as incident light. Item 14. An optical head according to any one of Items 1 to 13, wherein the optical head records information on a recording medium and / or reproduces information from the recording medium.

  According to this configuration, when recording information on the recording medium and / or reproducing information from the recording medium, it is possible to reduce the amount of deflection of the flying slider and to prevent problems such as contact between the flying slider and the recording medium. Can be provided, and an optical apparatus for optical recording / reproducing capable of stable flying can be provided.

  According to the first aspect of the present invention, by defining the weight of the optical element and the thickness of the flying slider, the deflection amount of the flying slider can be within an allowable value. This makes it possible to prevent problems such as the flying slider coming into contact with the recording medium, and to provide an optical head capable of stable flying.

  According to the second aspect of the present invention, the optical element can be handled without difficulty when the optical element and the flying slider are fixed to each other. Further, since the flying slider can be made small, the manufacturing cost can be reduced. Further, since the moment of inertia is reduced, positioning can be performed with high accuracy when the flying slider is driven in the radial direction of the recording medium during tracking, and the followability to the waviness of the recording medium is also improved. In addition, even when the flying slider comes into contact with the recording medium or other mechanical parts, the weight of the flying slider is light, so that the impact can be reduced.

  According to the third aspect of the present invention, there is no difficulty in handling the flying slider, and it is possible to prevent damage during handling. In addition, since the average thickness h of the flying slider is kept small, the thickness of the optical element fixed to the flying slider can be increased by that much to ensure the necessary thickness.

  According to the fourth aspect of the present invention, since the transmittance of the optical element is equal to or greater than a predetermined value, it is possible to reduce the amount of light necessary for recording and to suppress the heat generation due to the optical element absorbing light. . Furthermore, since the rotational speed of the recording medium can be kept low enough to be rotated by the bearing mechanism, thermal deformation of the optical element can be suppressed and stable optical performance can be exhibited under a stable rotational speed. . In addition, the decrease in the amount of near-field light that oozes out from the condensing point can be suppressed to a small level, so there is no difficulty in taking out near-field light, and recording / reproduction using near-field light can be performed stably. It becomes.

  According to the fifth aspect of the present invention, since the transmittance of the flying slider is equal to or higher than a predetermined value, it is possible to reduce the amount of light necessary for recording and to suppress the heat generated by the floating slider absorbing light. . Furthermore, since the rotation speed of the recording medium can be kept low to such an extent that it can be rotated by a bearing mechanism, thermal deformation of the flying slider is suppressed and stable flying on the recording medium is realized under a stable rotation speed. be able to. In addition, the decrease in the amount of near-field light that oozes out from the condensing point can be suppressed to a small level, so there is no difficulty in taking out near-field light, and recording / reproduction using near-field light can be performed stably. It becomes.

  According to the sixth aspect of the present invention, since the optical element has at least one of a refracting surface, a reflecting surface, and a diffractive surface, incident light can be effectively condensed at a predetermined position.

  According to the seventh aspect of the present invention, it is possible to bring the condensing position of incident light closer to the recording medium. Further, by defining the weight of the optical element and the thickness of the flying slider, the deflection amount of the flying slider can be within an allowable value. This makes it possible to prevent problems such as the flying slider coming into contact with the recording medium, and to provide an optical head capable of stable flying.

  According to the eighth aspect of the present invention, the incident light can be focused near the recording medium, and the optical element can be handled without difficulty when the optical element and the flying slider are fixed to each other. Can do. Further, since the flying slider can be made small, the manufacturing cost can be reduced. Further, since the moment of inertia is reduced, positioning can be performed with high accuracy when the flying slider is driven in the radial direction of the recording medium during tracking, and the followability to the waviness of the recording medium is also improved. In addition, even when the flying slider comes into contact with the recording medium or other mechanical parts, the weight of the flying slider is light, so that the impact can be reduced.

  According to the ninth aspect of the present invention, it is possible to bring the condensing position of incident light closer to the recording medium. Further, since there is no difficulty in handling the flying slider, it is possible to prevent damage during handling. Further, since the average thickness h of the flying slider is kept small, the thickness of the optical element fixed to the flying slider can be increased by that much, and the necessary thickness can be ensured.

  According to the invention described in claim 10, since the transmittance of the optical element is equal to or higher than a predetermined value, it is possible to reduce the amount of light necessary for recording and to suppress the heat generation due to the optical element absorbing light. . Furthermore, since the rotational speed of the recording medium can be kept low enough to be rotated by the bearing mechanism, thermal deformation of the optical element can be suppressed and stable optical performance can be exhibited under a stable rotational speed. . In addition, the decrease in the amount of near-field light that oozes out from the condensing point can be suppressed to a small level, so there is no difficulty in taking out near-field light, and recording / reproduction using near-field light can be performed stably. It becomes.

  According to the eleventh aspect of the invention, since the transmittance of the flying slider is equal to or higher than a predetermined value, it is possible to reduce the amount of light necessary for recording and to suppress the heat generated by the flying slider absorbing light. . Furthermore, since the rotation speed of the recording medium can be kept low to such an extent that it can be rotated by a bearing mechanism, thermal deformation of the flying slider is suppressed and stable flying on the recording medium is realized under a stable rotation speed. be able to. In addition, the decrease in the amount of near-field light that oozes out from the condensing point can be suppressed to a small level, so there is no difficulty in taking out near-field light, and recording / reproduction using near-field light can be performed stably. It becomes.

  According to the twelfth aspect of the invention, since the optical element has at least one of a refracting surface, a reflecting surface, and a diffractive surface, incident light can be effectively condensed at a predetermined position.

  According to the thirteenth aspect of the present invention, it is possible to prevent problems such as the floating slider coming into contact with the recording medium when recording information on the recording medium and / or reproducing information from the recording medium.

  According to the fourteenth aspect of the present invention, when recording information on the recording medium and / or reproducing information from the recording medium, the amount of deflection of the flying slider can be suppressed to a small value. It is possible to provide an optical apparatus for optical recording / reproducing that can prevent defects such as contact and can stably fly.

  FIG. 1 is a schematic view showing an embodiment of an optical apparatus for optical recording / reproducing according to the present invention. The optical recording / reproducing optical apparatus 100 includes a recording / reproducing optical system 50, a drive controller 80, and a flying slider 11 bonded to the optical element 10. Examples of the material of the optical element 10 and the flying slider 11 include glass such as Konica Minolta U-SF6M, Schott N-LAF34, Hoya M-FD80, Sumita Optical Glass K-VC82, and the like. . Moreover, translucent ceramics are ceramics excellent in translucency, for example, Lumicera of Murata Manufacturing Co., Ltd. is illustrated.

  The recording / reproducing optical system (light source) 50 emits a blue-violet laser beam having a wavelength of 405 nm when, for example, a Blu-ray disc that is a next-generation DVD standard is used as the recording medium 40 during recording. . Further, when recording, for example, when a normal compact disc (CD; Compact Disk) is used as the recording medium 40, a laser beam having a wavelength of 780 nm is emitted. The recording / reproducing optical system 50 also has a function of detecting the return light when the emitted laser light is reflected by the recording medium 40 and returned (during reproduction).

  During recording, laser light of a predetermined wavelength emitted from the recording / reproducing optical system 50 enters the optical element 10 and is condensed on a predetermined position, for example, on the surface of the flying slider 11 on the recording medium 40 side. Hereinafter, in this specification, the upward direction in FIG. 1 is defined as the upward direction, and the downward direction in FIG. 1 is defined as the downward direction. That is, the surface of the flying slider 11 on the recording medium 40 side is the “lower surface” of the flying slider 11, and the surface of the flying slider 11 on which the optical element 10 is bonded is the “upper surface” of the flying slider 11.

  When light is collected on the lower surface of the flying slider 11, the light oozes out slightly into the air from the flying slider 11 toward the recording medium 40 side. This oozing light is referred to as near-field light 90. In the embodiment of the present invention, information is recorded on the recording medium 40 and / or information is reproduced from the recording medium 40 using the near-field light 90. .

  The flying slider 11 is supported by a drive controller (positioner) 80 via a suspension 12. The optical element 10, the flying slider 11, and the suspension 12 are driven and controlled in the radial direction of the recording medium 40 by the drive controller 80 with the support shaft 17 as the rotation center. The lower surface of the flying slider 11 is mirror-polished, or has a concavo-convex pattern called a floating structure for ensuring stable flying by controlling the air flow flowing between the flying slider 11 and the recording medium 40. A so-called ABS (Air Bearing Surface) surface is formed.

  When the recording medium 40 is rotating at the time of recording or reproducing, an upward lift is exerted on the flying slider 11 by the air flow flowing between the flying slider 11 and the recording medium 40. By this lift, the flying slider 11 travels relatively stably on the recording medium 40 while maintaining a predetermined distance from the recording medium 40.

  However, the flying slider 11 is slightly bent due to the influence of the weight of the optical element 10, and the distance between the lower surface of the flying slider 11 and the upper surface of the recording medium 40 is not constant. That is, the flying slider 11 faces downward on the side where the optical element 10 is bonded, due to the distance (floating amount) between the lower surface of the flying slider 11 and the upper surface of the recording medium 40 in the vicinity of the bonding point between the flying slider 11 and the suspension 12. I am bent. Therefore, the distance (effective flying height t) between the near-field light 90 used for recording / reproduction and the upper surface of the recording medium 40 is reduced by subtracting this deflection from the flying height.

  The flying height of the flying slider 11 must be less than or equal to the wavelength order of the laser beam used for recording / reproducing, and is specifically set to about 10 (nm) to 50 (nm). For this reason, in order to prevent contact between the flying slider 11 and the recording medium 40 and perform stable recording / reproduction, the deflection amount needs to be smaller than the flying height.

  A condensing lens for narrowing the beam diameter of light to a predetermined size, a polarizing plate for adjusting the polarization direction of light, and the phase of light are provided between the recording / reproducing optical system 50 and the optical element 10. It is possible to appropriately arrange a device such as a quarter-wave plate for adjusting the frequency.

  The optical head 1 according to the present invention provided in the optical recording / reproducing optical apparatus 100 shown in FIG. 1 will be described below with reference to the drawings.

[Embodiment 1]
FIG. 2 is a schematic configuration diagram of the optical head according to the first embodiment. 2A is a view (top view) of the optical head 1 viewed from the incident light side (the side opposite to the recording medium 40), and FIG. 2B is a longitudinal sectional view of the optical head 1. FIG. FIG. 2C is a view (bottom view) of the optical head as viewed from the recording medium side. FIG. 2B is a cross-sectional view taken along the axis AX (through the center of the optical element-slider bonding portion 13 and the support shaft 17) in FIG. Hereinafter, in the present specification, the term “longitudinal sectional view” refers to a sectional view taken along the axis AX.

  The optical head 1 is bonded to the flying slider 11 and the flying slider 11 that travel relatively on the recording medium when the information is recorded on the recording medium 40 and / or the information is reproduced from the recording medium 40. It is comprised from the optical element 10 which condenses light to a predetermined position. The suspension 12 is bonded to the optical head 1 to support the weight of the optical head 1. Further, the suspension 12 is rotatable about the support shaft 17 as a fulcrum.

  The optical element 10 is made of a high refractive index material such as a glass material LaSF or LaF, for example, and condenses incident light such as a laser beam at a predetermined position such as a lower surface of the flying slider 11 or a recording layer in a recording medium. When the incident light is collected on the lower surface of the flying slider 11, the light oozes out in the air slightly from the light collection point as near-field light.

  As the optical element 10, in this embodiment, an example of a solid immersion mirror (SIM) is illustrated. The surface S1 on the incident light side of the solid immersion mirror (optical element 10) is coated with a multilayer film that transmits or reflects the light depending on the angle of the incident light. That is, when the angle formed between the normal direction of the surface S1 and the light incident on the surface S1 is small (when light enters the surface S1 from the air side), the reflectance by the surface S1 is small, and the surface S1 is mostly light. Transparent. On the other hand, when the angle formed by the normal direction of the surface S1 and the light incident on the surface S1 is large (when the light is once reflected by the surface S2 on the flying slider 11 side of the optical element 10 and then incident on the surface S1), Since the reflectance by the surface S1 is large, the surface S1 reflects most of the light.

  The surface S2 on the flying slider 11 side of the optical element 10 is coated with an Al film or the like, and is a mirror surface (light reflecting surface) that always reflects light. However, the center of the surface S2 has an opening that is not coated with an Al film or the like, and the light reflected by the surface S1 passes through the surface S2 through the opening. That is, the upper surface S1 of the solid immersion mirror functions as a refracting surface and a reflecting surface, and the lower surface S2 of the solid immersion mirror functions as a reflecting surface.

  The optical element 10 and the flying slider 11 are bonded to each other at the optical element-slider bonding portion 13 with UV (ultraviolet) curable resin. This UV curable resin is made of a material having a high transmittance in the wavelength region of light used as incident light, such as NOLAND 60 from Norland, 3514-HM from EM. Moreover, it is preferable that the center part (adhesion part) of the surface facing the flying slider 11 of the optical element 10 is a flat surface in order to enable stable adhesion. When the optical element 10 and the floating slider 11 are bonded, the relative inclination between the optical element 10 and the floating slider 11 is adjusted while observing the interference fringes at the bonding portion, and the optical element 10 and the floating slider 11 are bonded with a UV curable resin. The optical element 10 and the flying slider 11 may be fixed by a mechanical fitting structure or the like without using an adhesive such as a UV curable resin.

  Thus, the advantages of separately preparing the optical element 10 and the flying slider 11 and fixing them are that the optical head 1 with higher performance can be manufactured and the mass productivity is excellent. When viewed individually, the optical element 10 is suitable for production by a molding method in order to increase the processing accuracy of the surface shape. As for the flying slider 11, it is suitable to use, for example, a semiconductor process such as etching on the planar substrate for manufacturing the flying structure 16. Therefore, it is preferable to manufacture the respective members (the optical element 10 and the flying slider 11) by an optimum method and fix them.

  The flying slider 11 is bonded to the suspension 12 at a suspension-slider bonding portion 14. The flying slider 11 is stably supported on the recording medium by the suspension 12, and receives lift by the airflow flowing between the flying slider 11 and the recording medium 40 when the recording medium 40 rotates. As a result, the flying slider 11 travels relatively on the recording medium while maintaining a substantially constant distance (flying amount) from the recording medium 40.

  A flying structure 16 for controlling the air flow between the flying slider 11 and the recording medium 40 when the recording medium 40 is rotated on the surface facing the recording medium of the flying slider 11 to realize stable flying. Is formed. However, the height of the levitation structure 16 is about several tens to several hundreds (nm), which is considerably smaller than the thickness (about several mm) of the levitation slider 11, so that the longitudinal sectional view of FIG. Is not shown in FIG.

  Furthermore, a cut called an outflow end cut 15 is formed on the surface of the flying slider 11 on the recording medium side (the surface facing the recording medium). The outflow end cut 15 is for bringing the focal point closer to the recording medium 40, as will be described later. Further, the outflow end cut 15 is a portion that does not contribute to the flying of the flying slider 11, unlike the region having the flying structure 16.

  Hereinafter, also in the present embodiment and other embodiments, the description will be made on the assumption that the outflow end cut 15 is formed in the flying slider 11, but the embodiment according to the present invention is not limited thereto, and the flying slider 11 includes The outflow end cut 15 may not be formed. In particular, when the deflection of the flying slider 11 is small, such as when the optical element 10 is light or when the average thickness of the flying slider 11 is large, the focal point is brought closer to the recording medium 40 even if the outflow end cut 15 is not formed. Is possible.

  Incident light such as laser light used for recording and reproduction passes through the optical element 10 and the flying slider 11 and reaches the recording medium. Therefore, it is preferable that both the optical element 10 and the flying slider 11 are formed using a material having a high transmittance at least in the wavelength region of incident light.

  Specifically, at least one of the optical element 10 and the flying slider 11 is preferably made of a material having a transmittance with respect to incident light of 50% or more. Furthermore, it is more preferable that at least one of the optical element 10 and the flying slider 11 is made of a material having a transmittance with respect to incident light of 70% or more. This is because if the transmittance is low, the amount of light necessary for recording increases and the heat generation of the light source (recording / reproducing optical system 50) cannot be ignored. Further, not only the light source but also the heat generated by the optical element 10 and the flying slider 11 absorbing light cannot be ignored. And when the emitted-heat amount of the optical element 10 becomes large, thermal deformation will arise in the optical element 10, and it will become difficult to exhibit the stable optical performance. Further, when the amount of heat generated by the flying slider 11 increases, thermal deformation occurs in the flying slider 11, and the flying slider 11 does not float with respect to the recording medium 40.

  Hereinafter, the basis of the transmittance value will be described with reference to a diagram and a table showing specific experimental results. In FIG. 9, the recording medium 40 is irradiated with spot light, the temperature of the spot portion on the recording medium is plotted on the vertical axis, and the spot irradiation time (light irradiation time) is plotted on the horizontal axis. The result of the simulation performed based on the result of the experiment performed is shown. The intensity of the spot light is set to 36.6 (mW) as 100% (corresponding to the intensity of incident light before entering the optical element 10), and 32.9 (mW) (90%), 29.3 (other than that). The simulation was performed under a total of six conditions: mW) (80%), 25.6 (mW) (70%), 22.0 (mW) (60%), and 18.3 (mW) (50%). In the normal recording medium 40 used in this experiment, it is presumed that a recording mark is produced at around 300 ° C. Therefore, in order to perform recording, the spot light is continuously irradiated until the temperature of the spot portion reaches 300 ° C. There must be.

  Table 1 shows the correspondence between the intensity of the spot light and the time required for the temperature of the spot portion on the recording medium to reach 300 ° C. when the spot light of the intensity is used. That is, when the intensity of the spot light is 100%, the temperature reaches a value that can be recorded in 1 (μsec; microseconds), but when the intensity of the spot light is 70%, the temperature reaches 3 (μsec), and when the intensity is 50%. 10 (μsec), 3 times and 10 times as long as 100% are required.

  The rotational speed of the recording medium 40 used in the current HDD is about 5400 (rpm) to 15000 (rpm). In order to maintain the recording / reproducing data transfer speed at a practical level, the rotational speed 1 / 3 is the lower limit. Further, when the recording medium 40 is a disk, it is necessary to triple the time from when the recording medium 40 is irradiated with light until recording is possible (the light intensity is 70% of the incident light intensity). In order to perform recording / reproduction equivalent to the case where incident light with 100% intensity is used, the rotational speed of the disk must be reduced to 1/3.

  Therefore, in order to maintain the transfer rate of recording / reproducing data at a practical level, the intensity of the light applied to the disk needs to be 70% or more of the intensity of the incident light before entering the optical element 10. It is. This means that when the transmittance of the optical element 10 is 100%, the flying slider 11 is required to have a transmittance of 70% or more. Similarly, when the transmittance of the flying slider 11 is 100%, it means that the optical element 10 is required to have a transmittance of 70% or more.

  Next, as the rotational speed of the disk in the current HDD, 5400 (rpm) is assumed at the minimum in the IDE (Integrated Drive Electronics) standard. Ten times the number of revolutions is 54000 (rpm), which is substantially equal to the number of revolutions 50000 (rpm) at the high speed limit of a ball bearing made of bearing steel. If the light intensity is less than 50% of the incident light intensity, the number of revolutions of the disk must be increased 10 times or more, and this light intensity of 50% is a limit when recording / reproducing by rotating the disk.

  Further, the non-repetitive component (NRRO) that is not synchronized with the rotation around the spindle rotation axis affects the track pitch error in which the HDD data is recorded. In particular, NRRO is thought to be generated by airflow around the disk during high-speed rotation, vibration generated by the motor, etc., so it is impossible to extremely increase the disk rotation speed while keeping track pitch error small. Have difficulty. Therefore, the intensity of light applied to the disk is required to be 50% or more of the intensity of incident light, that is, the optical element 10 and the flying slider 11 are required to have a transmittance of 50% or more. Further, when the transmittances of the optical element 10 and the flying slider 11 are both 70%, the total transmittance of them combined (70% × 70%) is almost 50%.

  Further, when the transmittance is low, the amount of light collected at the condensing point decreases, so the amount of near-field light 90 that oozes from the condensing point also decreases accordingly. For this reason, problems such as difficulty in taking out the near-field light 90 and inability to stably perform recording / reproduction using the near-field light 90 occur. Also in this case, the transmittance of at least one of the optical element 10 and the flying slider 11 is preferably 50% or more, and more preferably 70% or more.

  The conditions regarding the transmittance of the optical element 10 and the flying slider 11 described above are not limited to the present embodiment, and the same applies to the other embodiments described below.

Further, the horizontal length of the flying slider 11 in FIG. 2A is l, the vertical length is b, and the vertical thickness is h as shown in FIG. 2B. Further, the length from the end of the flying slider 11 on the side where the optical element 10 is bonded to the center of the optical element-slider bonding part 13 is l ₁ , and the suspension element-slider bonding part from the center of the optical element-slider bonding part 13 14 is defined as l ₂ , and the length from the center of the suspension-slider bonding portion 14 to the end of the flying slider 11 on the suspension 12 side is defined as l ₃ . That is, l = l ₁ + l ₂ + l ₃ . Further, the lateral width in Figure 2 of the outflow end cuts 15 and l _4.

Hereinafter, the thickness h of the above is treated as a constant in the range of l _2, the thickness h in the case where the thickness varies in the range of l ₂ is intended to mean the average thickness of the range. In other words, the thickness h of the flying slider 11 is an average of the thicknesses of only the portion of the flying slider 11 that determines the amount of deflection (in this case, the range of l ₂ in FIG. 2).

Further, in the embodiment shown in FIG. 2, there are one optical element and slider, and one adhesion point between the suspension and the slider, that is, one point each of the optical element-slider adhesion part 13 and the suspension-slider adhesion part 14. However, the embodiment according to the present invention is not limited to this, and can also be applied to a case having a plurality of adhesive portions. For example, consider a case where the suspension 12 is bonded to the flying slider 11 at a plurality of points. In this case, the shortest length from the center of gravity of the plurality of bonding portions to the end of the flying slider 11 on the suspension 12 side is l ₃ . The same applies to the length l ₂ . That is, the lengths l ₂ and l ₃ are defined as the lengths up to the center of gravity of the bonded portions when there are a plurality of bonded portions. In the model calculation described later (see FIG. 5), the above definitions are used for the lengths l ₁ , l ₂ , and l ₃ .

  FIG. 3 is a schematic diagram for explaining an optical path when the optical element 10 condenses incident light. 3A shows a case where incident light is condensed on the surface of the flying slider 11 on the recording medium side, and FIG. 3B shows a case where incident light is condensed on the recording surface 41 of the recording medium 40. Yes.

  First, as shown in FIG. 3A, the incident light L1 to the optical element 10 is reflected by the surface S2 on the flying slider 11 side of the optical element 10, and subsequently the surface S1 of the optical element 10 on the incident light side. Then, the light passes through the opening of the surface S2. The light transmitted through the optical element 10 travels through the flying slider 11 toward the recording medium 40 and is collected on the lower surface of the flying slider 11. This condensed point is referred to as a condensing point 30. Then, the near-field light oozes out slightly in the air with the condensing point 30 as the center.

  Next, when the light is condensed on the recording layer 41 inside the recording medium 40, as shown in FIG. 3B, the incident light L2 to the optical element 10 is the surface of the optical element 10 on the flying slider 11 side. After being reflected by S2, and subsequently reflected by the surface S1 on the incident light side of the optical element 10, it is transmitted through the opening of the surface S2. Then, this light transmitted through the optical element 10 is also transmitted through the flying slider 11 and has a distance (effective flying height t) between the flying slider 11 and the recording medium 40 and a thickness of about 0.1 (mm). The light is condensed on the recording layer 41 in the recording medium 40 through the protective layer of the recording medium 40.

In the case of FIG. 3B, the light collected by the optical element 10 passes through the lower surface of the flying slider 11 and further proceeds in the air. Therefore, when the outflow end cut 15 is applied to the optical path L2, there occurs a problem that the light collecting point is shifted. Therefore, unlike the case of FIG. 3A, the outflow end cut 15 is required to have a shape that does not block the optical path L2. That is, the width l ₄ of the outflow end cut 15 needs to be smaller than l ₁ and set to a length that does not block the optical path L2.

  FIG. 4 is a schematic diagram for explaining a state in which the flying slider 11 is bent due to the weight of the optical element 10. The flying height F, which is the distance between the lower surface of the flying slider 11 and the upper surface of the recording medium 40, is defined as the distance from the position facing the suspension-slider bonding portion 14 to the upper surface of the recording medium 40 on the lower surface of the flying slider 11. The In optical recording / reproduction using near-field light, the flying height F needs to be maintained at about 10 (nm) to 50 (nm) by the lift received from the recording medium 40 on which the flying slider 11 rotates. . Therefore, the deflection amount d of the flying slider 11 due to the weight of the optical element 10 needs to be smaller than the flying height F.

  As shown in FIG. 4, the incident light travels along the optical path L <b> 3 and is collected at the condensing point 30. At this time, the condensing point 30 is preferably coincident with the lower end of the outflow end cut 15. Here, the lower end of the outflow end cut 15 is a point on the line of intersection between the surface of the outflow end cut 15 and the lower surface of the flying slider 11. As a result, it is possible to make the condensing point 30 closest to the recording medium 40 most effectively.

FIG. 5 is a schematic diagram showing a model for calculating the amount of deflection of the flying slider 11 due to the weight of the optical element 10. In the flying slider 11, the suspension - the portion from the slider adhesion portion 14 to the end of the suspension 12 of the floating slider 11 is not deflected, here ignores the length l _3. Therefore, one end of the modeled flying slider 11a is fixed to the wall 20 (fixed end), its length is l ₁ + l _{2 as} shown in the figure, and the thickness is h. Then, the weight w of the optical element 10 is applied to the load position in the figure.

  The amount of deflection ν at the load position is calculated by the following equation, where E is the longitudinal elastic modulus (Young's modulus), I is the sectional secondary moment, the unit of w is mg weight, and the unit of h is mm.

  Here, since the cross-sectional shape of the flying slider 11a is rectangular, the cross-sectional secondary moment I is calculated by the following equation.

  Since the deflection amount ν at the load position must be smaller than the flying height F, the sectional moment I is eliminated from the equations (1) and (2), and ν is 50 (nm) or less. We get the following formula:

Here, as a material of the flying slider 11, normally used quartz is assumed, and E = 80 (GPa), b = 1.5 (mm), and l ₂ = 1.5 (mm) in the formula (3). Substituting the value, we get

  In the above analysis, Equations (3) and (4) were derived on the assumption that ν is 50 (nm) or less. However, since near-field light is used, ν is smaller and preferably 10 (nm) or less. . In this case, equations (5) and (6) corresponding to equations (3) and (4), respectively, are as follows.

Substituting the above E, b, and l ₂ into the right side of Equation (3) and Equation (5) does not necessarily yield a numerical value that matches the right side of Equation (4) and Equation (6), respectively. Here, as an approximation, the equal signs are left as they are in the equations (4) and (6).

  Next, the range of the weight w of the optical element 10 will be considered. Hereinafter, a value of 3.81 is used as a typical specific gravity of glass. The weight w of the optical element 10 is preferably 0.2 (mg weight) or more and 40 (mg weight) or less. A value of 0.2 (mg weight) substantially corresponds to the weight of a cylinder having a diameter of 0.8 mm and a thickness of 0.1 (mm), for example. This size is the minimum value that can be handled when the optical element 10 and the flying slider 11 are bonded.

  Further, the value of 40 (mg weight) substantially corresponds to the weight of a cylinder having a diameter of 11.5 (mm) when considered with the same thickness of 0.1 (mm) as above. As the diameter of the optical element 10 increases, it is necessary to increase the width (particularly b) of the flying slider 11 accordingly.

  For example, near-field light-assisted magnetic recording has been studied as a next-generation hard disk drive (HDD). As the disk diameter of the HDD, those of 3.5, 2.5, 1.8, and 0.85 inches have been studied. Of these, a 0.85 inch diameter (diameter 22 (mm)) disc is intended for mobile devices, but in order to record / reproduce to / from this radius 11 (mm) disc, the width of the flying slider 11 is reduced. 11 (mm) or less is required. Therefore, by setting the weight of the optical element 10 to 40 (mg weight) or less, the width of the flying slider 11 is narrow enough to record / reproduce even with a 0.85 inch diameter disk, and the flying slider 11 11 can be reduced in overall size, thereby making it possible to reduce manufacturing costs.

  In addition, since the moment of inertia is reduced, positioning can be performed with high accuracy when the flying slider 11 is driven in the radial direction of the recording medium 40 during tracking, and the followability to the waviness of the recording medium 40 is also improved. Further, even when the flying slider 11 comes into contact with the recording medium 40 or other mechanical parts, the weight of the flying slider 11 is light, so that the impact can be suppressed small.

  Furthermore, the weight w of the optical element 10 is more preferably 1.0 (mg weight) or more and 15 (mg weight) or less. A value of 1.0 (mg weight) substantially corresponds to the weight of a cylinder having a diameter of 0.8 (mm) and a thickness of 0.5 (mm), for example. When the diameter of the optical element 10 is reduced, the light collection efficiency for incident light is reduced. Further, when the thickness of the optical element 10 is reduced, it becomes difficult to manufacture a refracting surface, a reflecting surface, or a diffractive surface for collecting incident light. The value of 1.0 (mg weight) is the minimum value that does not require difficulty in manufacturing a refracting surface, a reflecting surface, or a diffractive surface while keeping the light collection efficiency at a necessary size.

  Further, a value of 15 (mg weight) is substantially equivalent to the weight of a cylinder having a thickness of 7.5 (mm) when considered with the same diameter of 0.8 (mm) as above. In the case of a configuration in which a number of recording media 40 are stacked as in the current HDD, the height of the optical element 10 should be kept as low as possible in order to reduce the entire optical recording / reproducing optical apparatus.

  For example, the height of a 1.8-inch HDD (80 GB) manufactured by Toshiba that has already been mass-produced (the thickness in the direction of the rotation axis of the HDD disk) is 8 (mm). Therefore, the height of the optical element 10 needs to be within the range. That is, the height of the optical element 10 is preferably 8 (mm) or less. That is, the value of 15 (mg weight) is the maximum value that keeps the height of the optical element 10 within an allowable range while keeping the width of the flying slider 11 small.

  Next, the range of the thickness h of the flying slider 11 will be considered. The thickness h of the flying slider 11 is preferably 0.01 (mm) or more and 0.6 (mm) or less. When the thickness h is less than 0.01 (mm), it is difficult to handle such as being easily damaged during handling. On the other hand, if the thickness h is larger than 0.6 (mm), the thickness of the optical element 10 bonded to the flying slider 11 becomes thin, and the manufacture becomes difficult. Further, the value of 0.6 (mm) is a thickness of a slider of a current HDD called a nano slider. In an ordinary HDD, it is necessary to make the slider as thin as possible because of the structure in which the disks are stacked (stacked). Therefore, in order to reduce the size and weight in the future, it is preferable to make it thinner than the current slider thickness of 0.6 (mm).

  Furthermore, the thickness h of the flying slider 11 is more preferably 0.05 (mm) or more and 0.3 (mm) or less. When the thickness h is less than 0.05 (mm), it is difficult to perform handling by a human hand without using a machine. On the other hand, if the thickness h is greater than 0.3 (mm), the thickness of the optical element 10 becomes thin, making it difficult to manufacture the optical element 10 that maintains good optical characteristics such as off-axis aberrations.

  The range of the weight w of the optical element 10 described above, the range of the thickness h of the flying slider 11, and the relationship between the weight w and the thickness h defined by the equation (4) or (6) are as follows. The present invention is not limited to the form, and the same applies to other embodiments described below.

  In the present embodiment and the following other embodiments, the material of the optical element 10 and the flying slider 11 is preferably glass or translucent ceramic having a uniform refractive index and low light absorption. Furthermore, the one where the refractive index is higher is more preferable. When a material with a high refractive index is used, the radius of curvature may be large to obtain the same refractive power, and thus the thickness of the optical element 10 can be particularly reduced.

Further, glass or translucent ceramics preferably has good moldability in consideration of mass productivity, and it is preferable that etching or the like be easy in consideration of workability of the floating structure 16 of the flying slider 11 and the like. Therefore, as the material of the optical element 10 and the flying slider 11, transparent (excellent) workability quartz (SiO ₂ ), Pyrex (registered trademark) that can be etched, and the like can be used.

  When the weight w of the optical element 10 and the thickness h of the flying slider 11 satisfy the above-described expression (4), more preferably, the expression (6), the floating slider 11 is caused by the weight of the optical element 10. The amount of deflection can be kept smaller than the flying height. Therefore, stable recording / reproducing operations can be performed by using the optical recording / reproducing optical apparatus including the optical head according to the present invention.

[Other preferred embodiments]
(A) In the embodiment described above, as shown in FIG. 4, the surface of the outflow end cut 15 is formed so as to be substantially parallel to the upper surface of the recording medium 40 when the flying slider 11 is bent. . However, the present invention is not limited to this, and the outflow end cut of the flying slider 11 according to the embodiment of the present invention may have other shapes.

  FIG. 6 is a longitudinal sectional view showing another embodiment of the outflow end cut in the optical head. In the form shown in this figure, the outflow end cut 15a has a shape hollowed out from the flying slider 11 into a rectangular parallelepiped shape. The position of the end point x3 is assumed to be a condensing point. At this time, the end point x1 and the other end point x3 of the outflow end cut 15a are set so that the end point x3 is positioned closer to the recording medium 40 when the flying slider 11 is bent by the weight of the optical element 10. It is preferable that Thereby, similarly to the outflow end cut 15 in the first embodiment, even when the flying slider 11 is bent, it is possible to bring the focal point closer to the recording medium 40.

  Further, since the distance between the end point x2 and the end point x3 is small, the influence of the end point x2 blocking the optical path L4 is also small. However, it is also possible to prevent the optical path L4 from being blocked by shifting the position of the end point x2 to the end point x1 side.

  (B) In the embodiments described above, the optical element 10 is described as a solid immersion mirror (SIM). However, without being limited thereto, the optical element 10 according to the embodiment of the present invention may be another optical element such as a lens.

  FIG. 7 is a schematic diagram showing an optical head when a solid immersion lens (SIL) 10 a is used as the optical element 10. This figure is a longitudinal sectional view of the optical head 1 as in FIG. Incident light L5 to the solid immersion lens (optical element 10a) is refracted on the upper surface S3 of the optical element 10a and passes through the optical element 10a. That is, the upper surface S3 of the solid immersion lens functions as a refractive surface. The light transmitted through the optical element 10 travels further through the flying slider 11 toward the recording medium 40 and is collected on the lower surface of the flying slider 11. As in the first embodiment, the position of the condensing point 30b preferably coincides with one end of the outflow end cut 15.

  FIG. 8A is a schematic diagram showing an optical head when a diffractive lens 10b is used as the optical element 10, and FIG. 8B is a diagram illustrating a correspondence between a longitudinal sectional view and a top view of the diffractive lens 10b. It is the schematic diagram shown. Incident light L6 to the diffractive lens (optical element 10b) is diffracted at the upper surface S4 of the optical element 10b and passes through the optical element 10b. That is, the upper surface S4 of the diffractive lens has a function as a diffractive surface. The light transmitted through the optical element 10 travels further through the flying slider 11 toward the recording medium 40 and is collected on the lower surface of the flying slider 11. As in the first embodiment, the position of the condensing point 30c preferably coincides with one end of the outflow end cut 15.

  When this diffractive lens is viewed from above, concentric irregularities are formed as shown in FIG. The radius of the circle, the number of circles, and the like may be set as appropriate according to the wavelength of the laser beam used as incident light.

1 is a schematic diagram showing an embodiment of an optical apparatus for optical recording / reproducing according to the present invention. FIG. 2 is a schematic configuration diagram of the optical head according to the first embodiment, where (a) is a top view, (b) is a longitudinal sectional view, and (c) is a bottom view. 2A and 2B are schematic diagrams for explaining an optical path when an optical element collects incident light. FIG. 2A shows a case where light is condensed on the lower surface of the flying slider 11, and FIG. Each case is shown. It is a schematic diagram for demonstrating the state which the flying slider is bent by the weight of the optical element. It is a schematic diagram which shows the model for calculating the quantity which a flying slider bends with the weight of an optical element. It is a longitudinal cross-sectional view which shows another form of the outflow end cut in an optical head. It is a schematic diagram which shows the optical head at the time of using a solid immersion lens as an optical element. (A) is a schematic diagram which shows the optical head at the time of using a diffractive lens as an optical element, (b) is the schematic diagram which matched and showed the longitudinal cross-sectional view and top view of the said diffractive lens. Based on the results of experiments conducted by changing the spot light intensity, with the vertical axis representing the temperature of the spot irradiated with the spot light on the recording medium and the horizontal axis representing the time (light irradiation time) of the spot light irradiation. It is a graph which shows the result of another simulation.

Explanation of symbols

t Effective flying height d Deflection amount F Flying height 1 Optical head 10 Optical element 11 Lifting slider 12 Suspension 15 Outflow end cut 40 Recording medium 90 Near field light 100 Optical recording / reproducing optical apparatus

Claims (14)

A floating slider that floats in a state of maintaining a predetermined distance from the recording medium and relatively travels on the recording medium when recording information on and / or reproducing information from the recording medium;
An optical element fixed to the flying slider and condensing incident light at a predetermined position;
With
An optical head characterized by satisfying conditional expression w / h ³ ≦ 50000, wherein the weight of the optical element is w (mg weight) and the average thickness of the flying slider is h (mm).   2. The optical head according to claim 1, wherein the weight w of the optical element is 0.2 (mg weight) or more and 40 (mg weight) or less.   The optical head according to claim 1, wherein an average thickness h of the flying slider is 0.01 (mm) or more and 0.6 (mm) or less.   The optical head according to claim 1, wherein the optical element is made of a material having a transmittance of 50% or more for the incident light.   5. The optical head according to claim 1, wherein the flying slider is made of a material having a transmittance of 50% or more for the incident light.   6. The optical element according to claim 1, wherein the optical element has at least one of a refracting surface, a reflecting surface, and a diffractive surface for collecting the incident light at a predetermined position. Optical head. The surface facing the recording medium has a portion that does not contribute to flying, and when recording information on the recording medium and / or reproducing information from the recording medium, it floats in a state of maintaining a predetermined distance from the recording medium. A flying slider that travels relatively on the recording medium;
An optical element fixed to the flying slider and condensing incident light at a predetermined position;
With
An optical head characterized by satisfying conditional expression w / h ³ ≦ 50000, wherein the weight of the optical element is w (mg weight) and the average thickness of the flying slider is h (mm).   8. The optical head according to claim 7, wherein the weight w of the optical element is 0.2 (mg weight) or more and 40 (mg weight) or less.   9. The optical head according to claim 7, wherein an average thickness h of the flying slider is 0.01 (mm) or more and 0.6 (mm) or less.   The optical head according to claim 7, wherein the optical element is made of a material having a transmittance with respect to the incident light of 50% or more.   The optical head according to claim 7, wherein the flying slider is made of a material having a transmittance of 50% or more with respect to the incident light.   The optical head according to claim 7, wherein the optical element has any one of a refracting surface, a reflecting surface, and a diffractive surface for condensing the incident light at a predetermined position. A floating slider that travels relatively on the recording medium while maintaining a predetermined flying height when recording information on and / or reproducing information from the recording medium;
An optical element fixed to the flying slider and condensing incident light at a predetermined position;
An optical head characterized in that a deflection amount of the flying slider is smaller than the flying height. A light source that emits laser light of a predetermined wavelength;
The optical head according to claim 1, wherein laser light emitted from the light source is condensed at a predetermined position as incident light, and information is recorded on the recording medium and / or from the recording medium by the optical head. An optical apparatus for optical recording / reproducing, wherein information is reproduced.

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