JP4947794B2 - Information recording / reproducing device - Google Patents

Description

  The present invention relates to an information recording / reproducing apparatus that records and reproduces various information on a magnetic recording medium using near-field light.

  In recent years, the recording density of information within a single recording surface has increased as the capacity of hard disks and the like in computer equipment has increased. For example, in order to increase the recording capacity per unit area of the magnetic disk, it is necessary to increase the surface recording density. However, as the recording density increases, the recording area occupied by one bit on the magnetic recording medium decreases. When this bit size is reduced, the energy of 1-bit information is close to that of room temperature, and the recorded information is reversed or lost due to thermal fluctuation, etc. Will occur.

  In the in-plane recording method that has been generally used, the magnetism is recorded so that the direction of magnetization is in the in-plane direction of the magnetic recording medium. In this method, the recorded information is lost due to the thermal demagnetization described above. Etc. are likely to occur. Therefore, in order to solve such a problem, a perpendicular recording system is being recorded in which a magnetization signal is recorded in a direction perpendicular to the magnetic recording medium. This method is a method of recording magnetic information on the principle of bringing a single magnetic pole closer to a magnetic recording medium. According to this method, the recording magnetic field is directed substantially perpendicular to the recording film. Information recorded by a perpendicular magnetic field is easy to maintain in energy stability because it is difficult for the N pole and the S pole to form a loop in the recording film surface. Therefore, this perpendicular recording method is more resistant to thermal demagnetization than the in-plane recording method.

  However, recent magnetic recording media are required to have a higher density in response to the need to record and reproduce a larger amount of high-density information. For this reason, in order to minimize the influence of adjacent magnetic domains and thermal fluctuations, those having a strong coercive force have begun to be adopted as magnetic recording media. For this reason, it is difficult to record information on a magnetic recording medium even in the above-described perpendicular recording system.

  Therefore, in order to solve this problem, a hybrid that locally writes the magnetic domain by using spot light that collects light or near-field light to temporarily reduce the coercive force, and performs writing during that time. A magnetic recording system is provided. In particular, when near-field light is used, it is possible to handle optical information in a region that is less than or equal to the wavelength of light, which is a limit in conventional optical systems. Therefore, it is possible to achieve a higher recording bit density than conventional optical information recording / reproducing apparatuses.

  Various types of recording heads based on the hybrid magnetic recording system described above are provided. As one of the recording heads, a thin film magnetic head that performs heating using near-field light is known (Patent Document 1 and 2).

The thin film magnetic head includes a writing element mainly having a main magnetic pole layer and an auxiliary magnetic pole layer, and a near-field light generating layer for generating near-field light. The writing element and the near-field light generating layer are sequentially attached on the side surface (element forming surface) of the slider fixed to the tip of the load beam while being covered with the covering layer. At this time, the tips of the main magnetic pole layer, the auxiliary magnetic pole layer, and the near-field light generating layer are exposed from the coating layer and face the magnetic recording medium.
The main magnetic pole layer is connected to the auxiliary magnetic pole layer inside the coating layer. Accordingly, the main magnetic pole layer and the auxiliary magnetic pole layer constitute a single magnetic pole type vertical head in which one magnetic pole (single magnetic pole) is arranged in the vertical direction. The coil layer is disposed between the main magnetic pole layer and the auxiliary magnetic pole layer in a state of being insulated from both layers. These main magnetic pole layer, auxiliary magnetic pole layer and coil layer constitute an electromagnet as a whole.

  The near-field light generating layer is a metal layer made of various metal materials and is formed adjacent to the main magnetic pole layer. At this time, the near-field light generating layer is formed so as to taper toward the tip facing the magnetic recording medium. When laser light is incident on the near-field light generating layer, near-field light is generated from the tip. The coating layer serves as an optical waveguide for guiding the laser light emitted from the optical fiber to the near-field light generation layer, and has a multilayer structure in which layers formed of different materials are laminated.

  By the way, an optical fiber for guiding the laser beam to the slider is fixed to the load beam. The optical fiber is guided from the proximal end side to the distal end side along the upper surface of the load beam, and is then inserted into a dig formed in the slider while being bent downward by approximately 90 degrees. Thus, the laser beam can be irradiated from the upper side to the lower side so that the laser beam can enter the near-field light generating layer.

When the thin film magnetic head configured as described above is used, various information is recorded on the magnetic recording medium by generating a near-field light and simultaneously applying a recording magnetic field.
That is, laser light is first incident on the optical fiber. The incident laser light travels to the tip while bending along the curvature of the optical fiber, and then enters the coating layer. The laser light incident on the coating layer reaches the near-field light generating layer after traveling through the coating layer. Then, the near-field light generating layer causes the free electrons inside to be uniformly vibrated by this laser light, so that the plasmon is excited and the near-field light is generated in a localized state at the tip portion. As a result, the magnetic recording layer of the magnetic recording medium is locally heated by near-field light, and the coercive force temporarily decreases.
Further, by supplying a drive current to the coil layer simultaneously with the laser light irradiation, a recording magnetic field is locally applied to the magnetic recording layer of the magnetic recording medium close to the tip of the main magnetic pole layer. As a result, various kinds of information can be recorded on the magnetic recording layer whose coercive force has temporarily decreased. That is, recording on the magnetic recording medium can be performed by the cooperation of the near-field light and the magnetic field.
JP 2007-164935 A JP 2007-164936 A

However, the conventional thin film magnetic head described above still has the following problems.
First, in order to efficiently generate near-field light, it is generally necessary to make the light incident on an element (such as a near-field light generation layer) that generates near-field light with the polarization of light adjusted to an optimum state. There is. For example, when linearly polarized light is incident on the element, it is necessary to make the linearly polarized light enter in a predetermined direction. When elliptically polarized light is incident, It is necessary to make the light incident in a state where the elliptical direction is in a predetermined direction.
However, the optical fiber of the conventional thin film magnetic head is fixed in a state where the distal end side is greatly curved by approximately 90 degrees. For this reason, even if laser light whose polarization has been adjusted in advance is incident on the proximal end side of the optical fiber, the polarization direction is broken in the middle due to the bending of the optical fiber. For example, it is difficult to guide the laser beam to the tip of the optical fiber while keeping the direction of linearly polarized light in a predetermined direction. Therefore, the laser light emitted from the optical fiber is likely to be in an undesired polarization state.

  As a result, the generation efficiency of near-field light may be reduced or may not be generated in severe cases. Therefore, there arises a problem that writing of information on the magnetic recording medium becomes unstable or impossible.

  In order to solve the above-described problems as much as possible, a method of adjusting the polarization state of the laser light by calculating the bending of the optical fiber in advance is also conceivable. However, even if such a method is adopted, stress is inevitably applied to the optical fiber due to assembly errors during manufacturing, flying of the slider, and the like, so that the optical fiber is bent in an unpredictable manner. For this reason, even if the bending state of the optical fiber is calculated in advance and the polarization state of the laser light is adjusted, the polarization direction is lost during the process, and the laser light is emitted while the polarization state is maintained as desired. It was difficult to guide to the tip of the fiber.

  The present invention has been made in view of such circumstances, and its purpose is to allow a light beam in an optimal polarization state to enter the near-field light generating element regardless of the curved state of the optical waveguide that guides the light beam. An information recording / reproducing apparatus capable of stably writing information can be provided.

The present invention provides the following means in order to solve the above problems.
An information recording / reproducing apparatus according to the present invention is an information recording / reproducing apparatus for recording / reproducing information on a magnetic recording medium rotating in a certain direction by using near-field light, and is disposed opposite to the surface of the magnetic recording medium. A slider, a near-field light generating element for generating the near-field light from the introduced light beam, a recording element for recording information by applying a recording magnetic field to the magnetic recording medium, and a magnetic field leaking from the magnetic recording medium A near-field optical head having a reproducing element for reproducing information by outputting an electrical signal corresponding to the size of the magnetic recording medium, and movable in a direction parallel to the surface of the magnetic recording medium. And a beam that supports the near-field optical head in a state of being rotatable about two axes that are parallel to each other and orthogonal to each other, and a tip connected to the near-field optical head to guide the luminous flux to the near-field optical head. Flexible optical waveguide A light source connected to the base end side of the optical waveguide and incident on the optical waveguide in the state of linearly polarized light, and is interposed in the middle of the optical waveguide between the light source and the near-field optical head, A polarization adjustment mechanism that adjusts the polarization of the light beam traveling in the waveguide, and detects the generation state of the near-field light generated from the near-field light generation element, and activates the polarization adjustment mechanism according to the detection. And a control mechanism for generating near-field light having a light intensity necessary for recording at least information, and supporting the base end side of the beam and moving the beam in a direction parallel to the surface of the magnetic recording medium. An actuator for rotating the magnetic recording medium in the fixed direction, and a controller for adjusting polarization by operating the control mechanism at least before starting the recording of the information. That it comprises a and is characterized in.

  In the information recording / reproducing apparatus according to the present invention, after the magnetic recording medium is rotated in a certain direction by the rotation driving unit, the beam is moved by the actuator to scan the near-field optical head. Then, the near-field optical head is arranged at a desired position on the magnetic recording medium. At this time, the near-field optical head is supported by the beam so that it can rotate about two axes parallel to the surface of the magnetic recording medium and orthogonal to each other, that is, can be twisted about the two axes. Yes. Therefore, even if waviness occurs in the magnetic recording medium, changes in wind pressure due to waviness or waviness directly transmitted can be absorbed by twisting, and the attitude of the near-field optical head can be stabilized.

Thereafter, the recording element and the light source are activated. First, when the light source is activated, a linearly polarized light beam enters the proximal end side of the optical waveguide. The incident light beam travels in the optical waveguide and reaches the tip after passing through the polarization adjusting mechanism interposed in the middle. The light beam reaching the tip is incident on the near-field light head. Then, the near-field light generating element generates near-field light from the introduced light flux. The magnetic recording medium is locally heated by the near-field light, and the coercive force temporarily decreases. On the other hand, when the recording element operates, a recording magnetic field is applied to the magnetic recording medium. That is, a recording magnetic field can be applied to a magnetic recording medium having a reduced coercive force. As a result, information can be recorded by a hybrid magnetic recording method in which near-field light and a recording magnetic field cooperate.
The reproducing element outputs an electrical signal corresponding to the magnitude of the magnetic field leaking from the magnetic recording medium. Therefore, not only the information recording but also the information recorded on the magnetic recording medium can be reproduced based on the electric signal output from the reproducing element.

By the way, the control unit operates the control mechanism to perform polarization adjustment after operating the light source and generating near-field light at least before starting the above-described recording of information. Then, the control mechanism detects the generation state of the near-field light generated from the near-field light generating element. Here, when the polarization state of the light beam incident on the near-field light generating element substantially coincides with the optimum state, near-field light having a sufficiently strong light intensity for recording is detected. On the other hand, when the polarization state of the light beam is significantly deviated from the optimum state, the near-field light with weak light intensity insufficient for recording is detected or the near-field light itself is not detected.
Therefore, the control mechanism can grasp how much the polarization state of the light beam actually incident on the near-field light generating element is deviated from the optimum state based on the generation state of the near-field light. Then, the control mechanism operates the polarization adjusting mechanism so that at least near-field light having a light intensity necessary for recording information is generated.

In response to this, the polarization adjusting mechanism adjusts the polarization of the light beam traveling in the optical waveguide. As a result, the light beam can be guided to the near-field optical head in a state where the polarization state is as close as possible to the ideal state that is ideal. As a result, near-field light having at least a light intensity necessary for information recording can be generated, and information writing can be performed stably. Therefore, a high-quality information recording / reproducing apparatus with improved reliability can be obtained.
In particular, even if the optical waveguide is curved in the middle, it is possible to stably generate near-field light with the light intensity necessary for recording, regardless of the curved state, so the optical waveguide can be designed relatively freely. can do. In addition, since the polarization of the light beam can be changed appropriately according to the situation, even if the degree of curvature of the optical waveguide changes due to aging, stress, etc., the light intensity necessary for recording is not affected by these effects. Near-field light can be generated.

  Also, the information recording / reproducing apparatus according to the present invention is the information recording / reproducing apparatus according to the present invention, wherein the control mechanism activates the recording element and the light source on a trial basis to actually record the information. By detecting the above, the generation state of the near-field light is detected.

In the information recording / reproducing apparatus according to the present invention, at least before the information recording is started, the control mechanism activates the recording element and the light source on a trial basis, and the information is experimentally recorded on the magnetic recording medium by the hybrid magnetic recording method. Let's record. Then, the control mechanism reads this experimental record and detects whether or not the record has actually been made. In other words, if the information recorded on a trial basis can be read reliably, it can be determined that the recording has actually been performed, and therefore the control mechanism can reduce the polarization state of the light beam incident on the near-field light generating element to an optimum state. In agreement with each other, it is determined that a sufficiently strong light intensity for recording has occurred. On the other hand, if it is difficult to read information recorded on a trial basis or if it cannot be read at all, it can be determined that the recording has been insufficient. Therefore, the control mechanism can control the light flux incident on the near-field light generating element. It is judged that the polarization state has deviated significantly from the optimum state, and weak light intensity insufficient for recording has occurred.
Thus, by detecting whether or not recording has actually been performed, it is possible to detect the occurrence of near-field light. In particular, since the near-field light generation status is detected according to how the information actually recorded on a trial basis is read, the near-field light generation status can be grasped more accurately, and the polarization direction of the light beam can be changed more accurately. It can be adjusted with high accuracy.

  The information recording / reproducing apparatus according to the present invention is the information recording / reproducing apparatus according to the present invention, wherein the control mechanism is disposed adjacent to the magnetic recording medium and is generated from the near-field light generating element. A measurement unit that measures the light intensity of the field light, and a polarization controller that operates the polarization adjustment mechanism based on the light intensity measured by the measurement unit are provided.

  In the information recording / reproducing apparatus according to the present invention, in the state where the near-field light head is positioned above the measurement unit, the light source is operated to generate near-field light. Then, the measurement unit measures the light intensity of the near-field light generated from the near-field light generating element and outputs the measurement result to the polarization controller. Here, when the polarization state of the light beam incident on the near-field light generating element substantially matches the optimum state, a light intensity sufficient for recording is measured. On the other hand, when the polarization state of the light beam is greatly deviated from the optimum state, a weak light intensity insufficient for recording or a light intensity close to zero is measured. Thus, by measuring the light intensity, it is possible to detect the occurrence of near-field light.

  Then, the polarization controller can grasp how much the polarization state of the light beam actually incident on the near-field light generating element is deviated from the optimum state based on the light intensity measured by the measurement unit. . Then, the polarization controller operates the polarization adjustment mechanism so that at least light intensity necessary for recording information is generated. As a result, near-field light having at least a light intensity necessary for information recording can be generated, and information writing can be performed stably.

  The information recording / reproducing apparatus according to the present invention is the information recording / reproducing apparatus according to the present invention, wherein the polarization controller operates the polarization adjusting mechanism so that the light intensity measured by the measuring unit is maximized. It is characterized by.

  In the information recording / reproducing apparatus according to the present invention, the polarization controller operates the polarization adjusting mechanism so that the light intensity is maximized, not at least the minimum light intensity necessary for information recording. That is, the polarization adjustment mechanism is operated so that the polarization state of the light beam matches the optimum state. As a result, information can be recorded more stably, and higher density recording can be achieved.

  The information recording / reproducing apparatus according to the present invention is the information recording / reproducing apparatus according to the present invention, wherein the polarization controller compares the light intensity measured by the measuring unit with a preset light intensity threshold value. When the measured light intensity is lower than the threshold value, a correction value that cancels the difference is calculated, and the polarization adjusting mechanism is operated by the calculated correction value.

In the information recording / reproducing apparatus according to the present invention, when the polarization controller operates the polarization adjustment mechanism, first, the measured light intensity is compared with a preset light intensity threshold. At this time, if the measured light intensity is larger than the threshold value, it is determined that near-field light having a light intensity sufficient for recording information is generated, and the polarization adjustment mechanism is not operated.
On the other hand, when the measured light intensity is lower than the threshold value, it is determined that near-field light having a light intensity sufficient for recording information is not generated, and the polarization adjusting mechanism is operated. At this time, the polarization controller calculates a correction value that cancels out the difference between the measured light intensity and the threshold value, and operates the polarization adjustment mechanism by this calculated correction value to correct the polarization state.
Thereby, at least near-field light having a light intensity necessary for recording information can be reliably generated.

  The information recording / reproducing apparatus according to the present invention is the information recording / reproducing apparatus according to the present invention, wherein the polarization controller is configured such that the light intensity measured by the measuring unit matches a preset light intensity threshold. The polarization adjusting mechanism is operated while performing feedback control.

  In the information recording / reproducing apparatus according to the present invention, when the polarization controller operates the polarization adjustment mechanism, the polarization adjustment mechanism while performing feedback control so that the measured light intensity coincides with a preset light intensity threshold value. Is activated. Thereby, at least near-field light having a light intensity necessary for recording information can be reliably generated.

  The information recording / reproducing apparatus according to the present invention is the information recording / reproducing apparatus according to the present invention, wherein the polarization adjusting mechanism rotates the polarization direction of the incident light beam in a linearly polarized state around the axis of the optical waveguide. Thus, the polarization direction is adjusted, and the linearly polarized light is incident on the near-field optical head.

  In the information recording / reproducing apparatus according to the present invention, when the polarization adjustment mechanism receives an instruction from the control mechanism, the polarization direction is adjusted by rotating the polarization direction of the light beam traveling in the optical waveguide around the axis of the optical waveguide. To do. Thereby, the polarization direction of the light beam can be as close as possible to a predetermined optimum direction. Therefore, it is possible to guide the light beam to the near-field optical head after the polarization state is optimized. As a result, near-field light having at least a light intensity necessary for information recording can be generated, and information writing can be performed stably.

  According to the information recording / reproducing apparatus of the present invention, it is possible to make a light beam in an optimal polarization state incident on the near-field light generating element regardless of the bending state of the optical waveguide that guides the light beam. Accordingly, information can be stably written, and reliability and quality can be improved.

(First embodiment)
A first embodiment according to the present invention will be described below with reference to FIGS. Note that the information recording / reproducing apparatus 1 of the present embodiment performs writing on a disk (magnetic recording medium) D by a perpendicular recording method, and utilizes the flow of air that rotates the disk D, and the near-field optical head 2. A description will be given by taking as an example an air levitation type that floats.

  The information recording / reproducing apparatus 1 of this embodiment is an apparatus that records and reproduces information on a disk D that rotates in a certain direction using near-field light R. As shown in FIG. 1, the information recording / reproducing apparatus 1 guides an optical near-field optical head 2, a beam 3 that supports the near-field optical head 2, and a laser beam (light beam) L to the near-field optical head 2. An optical waveguide 4; an optical signal controller (light source) 5 that causes the laser light L to enter the optical waveguide 4; a polarization adjustment mechanism 6 that adjusts the polarization of the laser light L; a control mechanism 7 that operates the polarization adjustment mechanism 6; An actuator 8 that moves the beam 3, a spindle motor (rotation drive unit) 9 that rotates the disk D in a certain direction, a control unit 10 that comprehensively controls each of the above-described components, and each component is housed inside. And a housing 11 to be used.

The housing 11 is made of a metal material such as aluminum and has a substantially square shape when viewed from above, and a recess 11a for accommodating each component is formed inside. Further, a lid (not shown) is detachably fixed to the housing 11 so as to close the opening of the recess 11a. The spindle motor 9 is attached to substantially the center of the recess 11a, and the disc D is detachably fixed by fitting the center hole into the spindle motor 9.
The actuator 8 is attached to the corner of the recess 11a. A carriage 13 is attached to the actuator 8 via a bearing 12, and the base end side of the beam 3 is fixed to the tip of the carriage 13. In this way, the actuator 8 can scan and move the beam 3 in the XY directions parallel to the disk surface (the surface of the magnetic recording medium) D1 while supporting the base end side of the beam 3. It has become.

  The beam 3 is movable in the XY direction together with the carriage 13 by the actuator 8 as described above, and is rotatable about two axes (X axis and Y axis) that are parallel to the disk surface D1 and orthogonal to each other. In the state, the near-field light head 2 is supported on the tip side. The beam 3 and the carriage 13 are retracted from the disk D by driving the actuator 8 when the disk D stops rotating.

As shown in FIGS. 2 to 4, the beam 3 is formed of a thin metal material such as stainless steel, and is fixed to the distal end of the carriage 13 through an opening 3a formed on the proximal end side. It has become. FIG. 2 is a perspective view of the entire beam 3 as viewed obliquely with the near-field light head 2 facing downward. FIG. 3 is a perspective view of the entire beam 3 as viewed obliquely with the near-field light head 2 facing upward. FIG. 4 is a sectional view of the tip of the beam 3 with the near-field optical head 2 facing upward.
An opening 3b extending in the width direction (arrow W direction) is formed at an intermediate position of the beam 3 (a position where the beam 3 is switched from a square shape to a taper shape when viewed from above). Thereby, the cross-sectional area along the width direction of the beam 3 is extremely smaller than other portions. Therefore, the beam 3 is bent around the intermediate position and is easily bent in the Z direction perpendicular to the disk surface D1. That is, both sides sandwiching the opening 3b serve as hinges.

As shown in FIG. 5, the near-field light head 2 includes a slider 20 disposed opposite to the disk surface D1 and a near-field light generating element that generates near-field light R from the laser light L introduced by the optical waveguide 4. 21, a recording element 22 that records information by applying a recording magnetic field to the disk D, and a reproducing element 23 that outputs an electrical signal corresponding to the magnitude of the magnetic field leaking from the disk D.
The slider 20 is formed in a rectangular parallelepiped shape with a light-transmitting material such as quartz glass or a ceramic such as AlTiC (altic). The slider 20 is supported so as to hang from the tip of the beam 3 via the gimbal portion 24 with the opposing surface 20a facing the disk D. The gimbal portion 24 is a component whose movement is restricted so as to be displaced only around the X axis and around the Y axis. As a result, the slider 20 is rotatable about two axes (X axis and Y axis) that are parallel to the disk surface D1 and orthogonal to each other as described above. In FIG. 5, the gimbal portion 24 is schematically illustrated.

Here, the detailed configuration of the gimbal portion 24 will be briefly described with reference to FIGS. A sheet-like gimbal plate 25 whose outer shape is formed in a substantially square shape is attached to the lower surface side of the tip of the beam 3. The gimbal plate 25 is made of a metal material such as stainless steel, and is formed to slightly warp downward from the middle to the tip. The distal end side to which the warp is applied is fixed to the beam 3 from the base end side to the vicinity of the middle so as not to contact the beam 3.
In addition, a pad portion 26 is formed on the tip side of the gimbal plate 25 in a state of being lifted from the beam 3, and the periphery of the pad portion 26 is formed in a U shape. Only the pad portion 26 is parallel to the lower surface of the beam 3. The angle is adjusted so that The near-field light head 2 is placed and fixed on the pad portion 26. That is, the near-field light head 2 is in a state of hanging from the tip of the beam 3 via the pad portion 26. Note that a fitting hole 25 a into which the tip of the optical waveguide 4 is fitted is formed at a portion where the pad portion 26 and the gimbal plate 25 are connected.

Further, a projection 27 is formed at the tip of the beam 3 so as to protrude toward the approximate center of the pad portion 26 and the near-field light head 2. The tip of the projection 27 is rounded. The protrusion 27 comes into point contact with the surface of the pad portion 26 when the near-field light head 2 floats to the beam 3 side by the wind pressure received from the disk D. This rising force is transmitted from the projection 27 to the beam 3 and acts to bend the beam 3 in the Z direction.
Further, when wind pressure is applied to the near-field light head 2 due to the undulation of the disk D, the near-field light head 2 and the pad portion 26 are twisted around the X-axis and Y-axis described above around the protrusion 27. It is like that. Thereby, the wind pressure resulting from the undulation of the disk D can be absorbed, and the attitude of the near-field optical head 2 at the time of flying is stabilized.
That is, the gimbal plate 25 having the protrusions 27 and the pad portions 26 functions as the gimbal portion 24 described above.

By the way, on the facing surface 20a of the slider 20, a protruding strip portion (not shown) that generates a pressure for rising from the viscosity of the air flow generated by the rotating disk D is formed. In addition, the surface of a protruding item | line part is made into ABS (Air Bearing Surface).
The slider 20 receives a force that rises from the disk surface D <b> 1 by the convex portion. At this time, since the beam 3 is bent in the Z direction perpendicular to the disk surface D1 as described above, the flying force of the slider 20 is absorbed. That is, the slider 20 receives a force pressed against the disk surface D1 side by the beam 3 when it floats. Therefore, as shown in FIG. 5, the slider 20 floats in a state of being separated from the disk surface D1 by a predetermined distance H due to the balance between the forces of the two. Moreover, since the slider 20 is rotated about the X axis and the Y axis by the gimbal portion 24, the slider 20 always floats in a stable posture.
The air flow generated by the rotation of the disk D flows from the inflow end side (base end side of the beam 3) of the slider 20 and then flows along the ABS to the outflow end side of the slider 20 (tip of the beam 3). Side).

  As shown in FIG. 5, the recording element 22 is fixed to the side surface (tip surface) on the outflow end side of the slider 20, and is connected to the auxiliary magnetic pole 30 via an auxiliary magnetic pole 30 and a magnetic circuit 31. A main magnetic pole 32 that generates a recording magnetic field perpendicular to D with respect to the auxiliary magnetic pole 30 and a coil 33 that spirally winds around the magnetic circuit 31 around the magnetic circuit 31 are provided. Both the magnetic poles 30 and 32 and the magnetic circuit 31 are formed of a high saturation magnetic flux density (Bs) material (for example, a CoNiFe alloy, a CoFe alloy, or the like). Further, the coil 33 is disposed so that there is a gap between adjacent coil wires, between the magnetic circuit 31 and between the magnetic poles 30 and 32 so as not to be short-circuited. Molded. The coil 33 is supplied with a current modulated according to information from the control unit 10. That is, the magnetic circuit 31 and the coil 33 constitute an electromagnet as a whole.

  Further, the near-field optical head 2 of this embodiment includes a light flux propagation element 35 fixed adjacent to the recording element 22. The light flux propagation element 35 is an optical element that propagates the laser light L emitted from the optical waveguide 4 toward the end face 35 a facing the disk D. The near-field light generating element 21 is formed on the end face 35 a of the light flux propagation element 35. As shown in FIG. 6, the near-field light generating element 21 includes a light shielding film 36 formed on the end face 35 a and a triangular minute opening 37 formed in the approximate center of the light shielding film 36. Yes.

  Further, as shown in FIG. 5, the reproducing element 23 is fixed adjacent to the light beam propagation element 35. The reproducing element 23 is a magnetoresistive effect film whose electric resistance is converted in accordance with the magnitude of the magnetic field leaking from the disk D. A bias current is supplied from the control unit 10 through a lead film (not shown). Yes. Thus, the control unit 10 can detect a change in the magnetic field leaked from the disk D as a change in voltage, and can reproduce a signal from the change in voltage.

  As shown in FIG. 7, the optical waveguide 4 is a waveguide including a core 4a and a clad 4b, and the laser light L propagates through the core 4a. 2 and 4, the optical waveguide 4 is fixed to the upper surface of the beam 3 along the beam 3, the proximal end side is connected to the optical signal controller 5, and the distal end side is a near field. It is fixed to the optical head 2. At this time, the distal end side of the optical waveguide 4 is fitted into the fitting hole 25a of the gimbal plate 25 in a state of being bent approximately 90 degrees after passing the distal end of the beam 3. As a result, the laser light L can be incident on the light flux propagation element 35 of the near-field light head 2.

  As shown in FIG. 1, the optical signal controller 5 is attached in the recess so as to be adjacent to the actuator 8, and makes the laser light L enter the optical waveguide 4 from the base end side. In addition, when the laser signal L is incident, the optical signal controller 5 allows the laser beam L to be incident in a linearly polarized state.

As shown in FIGS. 1 and 5, the polarization adjusting mechanism 6 is interposed in the middle of the optical waveguide 4 between the optical signal controller 5 and the near-field optical head 2, and transmits the laser light L traveling in the optical waveguide 4. The polarization is adjusted. More specifically, the polarization adjustment mechanism 6 adjusts the polarization direction to an arbitrary direction by rotating the polarization direction of the laser light L incident in the state of linear polarization around the axis L1 of the optical waveguide 4, and linearly polarized light. The light is incident on the near-field light head 2 as it is. The polarization adjusting mechanism 6 of this embodiment is fixed adjacent to the optical signal controller 5.
As shown in FIG. 8, the polarization adjusting mechanism 6 has a half-wave plate 6a that changes the polarization direction of linearly polarized light. The half-wave plate 6a has an optical axis in the direction of arrow B, and is configured to rotate around the axis L1 via a metal frame 6b. As a result, the polarization direction of the linearly polarized laser beam L emitted from the optical signal controller 5 can be changed to a different direction. In FIG. 8, a case where the polarization direction is changed by approximately 90 degrees before and after passing through the half-wave plate 6a is shown as an example.

The control mechanism 7 detects the generation state of the near-field light R generated from the near-field light generating element 21 and operates the polarization adjusting mechanism 6 in response to the detection to at least light necessary for recording information. Intense near-field light R is generated.
As shown in FIG. 5, the control mechanism 7 of the present embodiment includes a polarization controller 7a connected to the reproducing element 23 and the polarization adjustment mechanism 6, respectively. The recording element 22 and the optical signal controller 5 are tested on a trial basis. The generation state of the near-field light R is detected by operating it and reading the detection element 23 to detect whether or not the recording of information has actually been performed on the disk D. Therefore, the reproducing element 23 is a combined component that also functions as the control mechanism 7. However, the reproducing element 23 may not be used in combination, but another reproducing element that reads information recorded on a trial basis may be provided in the near-field optical head 2 as a dedicated component of the control mechanism 7.

The polarization controller 7a grasps the generation state of the near-field light R based on the reading state of the reproducing element 23, and sends a signal to the polarization adjustment mechanism 6 in response thereto to rotate the half-wave plate 6a. The polarization controller 7 a is incorporated in the control unit 10.
As shown in FIG. 1, the control unit 10 is mounted in the recess of the housing 11 so as to be adjacent to the actuator 8. The control unit 10 operates the control mechanism 7 to perform polarization adjustment at least before officially starting to record information. For example, the beam 3 is moved in the X and Y directions by the actuator 8 so that the near-field optical head 2 is retracted from the disk D, and thereafter, the polarization adjustment is performed every time it returns to the disk D again.

Next, a case where various kinds of information is recorded / reproduced on / from the disk D by the information recording / reproducing apparatus 1 configured as above will be described below.
First, the spindle motor 9 is driven to rotate the disk D in a certain direction. Next, the actuator 8 is actuated to scan the beam 3 in the XY directions via the carriage 13. As a result, the near-field optical head 2 can be positioned at a desired position on the disk D as shown in FIG. At this time, the near-field optical head 2 receives a force that rises by a protruding portion formed on the opposing surface 20a of the slider 20, and is pressed against the disk D side by a predetermined force by the beam 3 or the like. The near-field optical head 2 floats at a position separated from the disk D by a predetermined distance due to the balance of both forces.

  Further, even if the near-field optical head 2 receives the wind pressure generated due to the undulation of the disk D, the beam 3 absorbs the displacement in the Z direction and is displaced around the XY axis by the gimbal portion 24. Can be absorbed, so wind pressure caused by swell can be absorbed. Therefore, the near-field light head 2 can be floated in a stable state.

Here, when recording information, the control unit 10 operates the optical signal controller 5 and supplies the coil 33 with a current modulated according to the information.
First, the optical signal controller 5 receives linearly polarized laser light L from the base end side of the optical waveguide 4 in response to an instruction from the control unit 10. The incident laser light L travels toward the tip side in the core 4a of the optical waveguide 4, and reaches the tip after passing through the half-wave plate 6a of the polarization adjusting mechanism 6 interposed in the middle. Then, the laser light L that has reached the tip of the optical waveguide 4 is incident on the light flux propagation element 35 of the near-field optical head 2 as shown in FIG. The light beam incident on the light beam propagation element 35 propagates toward the disk D and reaches the near-field light generating element 21 formed on the end face 35a. Then, most of the laser light L is shielded by the light shielding film 36, but a part of the laser light L leaks outside through the minute opening 37 and becomes the near-field light R. That is, the near-field light R localized in the vicinity of the minute opening 37 can be generated. Then, the disk D is locally heated by the near-field light R, and the coercive force temporarily decreases.

  On the other hand, when a current is supplied to the coil 33 by the controller 10 simultaneously with the introduction of the laser beam L described above, the current magnetic field generates a magnetic field in the magnetic circuit 31 by the principle of the electromagnet, so that the main pole 32 and the auxiliary pole 30, a perpendicular recording magnetic field can be applied to the disk D. Then, as shown in FIG. 5, the magnetic flux generated from the main magnetic pole 32 side passes straight through the perpendicular recording layer (not shown) of the disk D and reaches the soft magnetic layer (not shown). As a result, recording can be performed with the magnetization of the perpendicular recording layer oriented perpendicular to the disk surface D1. Further, the magnetic flux reaching the soft magnetic layer returns to the auxiliary magnetic pole 30 via the soft magnetic layer. At this time, when returning to the auxiliary magnetic pole 30, the magnetization direction is not affected. This is because the area of the auxiliary magnetic pole 30 facing the disk surface D1 is larger than that of the main magnetic pole 32, so that the magnetic flux density is large and a force sufficient to reverse the magnetization does not occur. That is, recording can be performed only on the main magnetic pole 32 side.

  As a result, information can be recorded by a hybrid magnetic recording method in which the near-field light R and the recording magnetic field generated between the magnetic poles 30 and 32 cooperate. In addition, since the recording is performed by the vertical recording method, it is difficult to be affected by the thermal fluctuation phenomenon and the like, and stable recording can be performed. Therefore, writing reliability can be improved.

  Next, a case where information recorded on the disk D is reproduced will be described. In this case, since the reproducing element 23 receives a magnetic field leaking from the perpendicular recording layer of the disk D, the electric resistance changes according to the magnitude. Therefore, the voltage of the reproducing element 23 changes. Thereby, the control unit 10 can detect a change in the magnetic field leaking from the disk D as a change in voltage. And the control part 10 can reproduce | regenerate information by reproducing | regenerating a signal from the change of this voltage.

By the way, when generating the near-field light R, as shown in FIG. 6, linearly polarized light is directed in a direction (arrow P1 direction) orthogonal to any one side of the triangular aperture 37 formed in a triangular shape. It is preferable to introduce the laser beam L into. In this way, the near-field light R can be intensively generated on one side of the minute opening 37 orthogonal to the polarization direction (P1 direction). Therefore, the light intensity of the near-field light R can be increased, and information can be stably written by heating the disk D more.
Thus, in order to record information stably, it is important to match the direction of linearly polarized light as much as possible with the polarization direction (arrow P1 direction) described above. By making them coincide with each other, the polarization state of the laser light L can be brought into an optimum state that is ideal for generating the near-field light R most efficiently. This polarization direction (arrow P1 direction) is hereinafter referred to as a predetermined direction.

Therefore, the control unit 10 operates the optical signal controller 5 to generate the near-field light R at a stage before starting the above-described information recording, and then operates the control mechanism 7 to perform polarization adjustment. .
More specifically, first, when the information recording / reproducing apparatus 1 is turned on and the actuator 8 scans and moves the beam 3, the near-field light head 2 is positioned above the test area previously formed on the disk D. Let After the near-field optical head 2 reaches the test area, the control mechanism 7 operates the recording element 22 and the optical signal controller 5 on a trial basis to record information on the disc D on a trial basis using the hybrid magnetic recording method. Make it. Then, the control mechanism 7 uses the reproducing element 23 to read this experimental record. The reproducing element 23 outputs the read result to the polarization controller 7a. The polarization controller 7a detects the generation state of the near-field light R from the sent reading result.

Here, if the information recorded on a trial basis can be reliably read by the reproducing element 23, it can be determined that the recording has actually been performed. Therefore, the polarization controller 7a can detect the laser incident on the near-field light generating element 21. The polarization direction of the light L is substantially coincident with a predetermined direction (the polarization state of the laser light L is substantially coincident with the optimum state), and it is determined that a light intensity having a strong intensity sufficient for recording is generated. On the other hand, if it is difficult or impossible to read information recorded on a trial basis by the reproducing element 23, it can be determined that the recording has been insufficient. The polarization direction of the laser beam L incident on the beam 21 is greatly deviated from a predetermined direction (the polarization state of the laser beam L is largely deviated from the optimum state), and the light intensity of weak intensity insufficient for recording is low. Judge that it occurred.
In this way, the polarization controller 7a can detect the generation state of the near-field light R by detecting whether or not recording has actually been performed using the reproducing element 23.

  Then, the polarization controller 7a determines how much the polarization direction of the laser light L actually incident on the near-field light generating element 21 is deviated from a predetermined direction based on the generation state of the near-field light R. You can figure out. Then, the polarization controller 7a operates the polarization adjustment mechanism 6 so that at least near-field light R having a light intensity necessary for recording information is generated.

  In response to this, the polarization adjusting mechanism 6 rotates the half-wave plate 6a. Thereby, the polarization direction of the laser beam L traveling in the optical waveguide 4 can be rotated around the axis L1, and the polarization direction can be adjusted. Accordingly, the laser beam L is guided to the near-field light generating element 21 in a state where the polarization direction of the laser beam L is as close as possible to a predetermined direction, that is, in a state where the polarization state of the laser beam L is as close as possible to the optimum state. Can do. As a result, it is possible to generate near-field light R having a light intensity necessary for recording at least information.

Then, after the adjustment of the polarization direction is completed, the actuator 8 scans and moves the beam 3 to a desired position on the disk D as described above, and starts recording formal information. At this time, at least the near-field light R having the light intensity necessary for information recording can be reliably generated, so that information can be stably written. Therefore, it is possible to improve reliability and improve quality.
In particular, since the near-field light R having the light intensity necessary for recording can be stably generated regardless of the bending state of the optical waveguide 4, the optical waveguide 4 can be freely designed. In addition, since the polarization direction of the laser beam L can be changed as appropriate, even if the degree of curvature of the optical waveguide 4 changes due to aging, stress, or the like, it is necessary for recording without being affected by these effects. The near-field light R having the light intensity can be continuously generated.

As described above, according to the information recording / reproducing apparatus 1 of the present embodiment, the polarization direction is directed in a desired direction with respect to the near-field light generating element 21 regardless of the bending state of the optical waveguide 4 that guides the laser light L. In this state, linearly polarized laser light L can be incident. That is, the laser beam L in an optimal polarization state can be incident on the near-field light generating element 21. Accordingly, information can be stably written, and reliability and quality can be improved.
In addition, since the occurrence state of the near-field light R is detected according to the reading of information actually recorded on a trial basis, the occurrence state of the near-field light R can be grasped more accurately, and the laser light L It is easy to adjust the polarization direction with higher accuracy.

(Second Embodiment)
Next, a second embodiment according to the present invention will be described with reference to FIGS. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. The difference between the second embodiment and the first embodiment is that in the first embodiment, whether or not the information recorded on a trial basis has actually been recorded is detected to determine the generation state of the near-field light R. Although detected, in the second embodiment, the light intensity of the near-field light R is actually measured to detect the generation state of the near-field light R.

  That is, the information recording / reproducing apparatus 40 of this embodiment includes a control mechanism 41 including a measurement unit 41a and a polarization controller 41b, as shown in FIG. The measuring unit 41 a is disposed adjacent to the disk D and measures the light intensity of the near-field light R generated from the near-field light generating element 21. More specifically, in the recess 11a of the housing 11 of the present embodiment, as shown in FIG. 10, when the near-field light head 2 is retracted from the disk D, it is attached to the tip of the beam 3. A ramp mechanism 42 is provided adjacent to the disk D, on which the tabs that are not to be mounted. The lamp mechanism 42 is provided with a measuring unit 41a. At this time, as shown in FIG. 11, the measurement unit 41 a is provided to face the facing surface 20 a of the slider 20 when the near-field light head 2 is retracted to the lamp mechanism 42.

  The measurement unit 41a has a projection (not shown) that slightly protrudes toward the near-field light generating element 21, and optically detects the scattered light of the near-field light R that is scattered by hitting the projection. It is an optical sensor that measures the light intensity of the near-field light R. Then, the measuring unit 41a outputs the measured light intensity to the polarization controller 41b. On the other hand, the polarization controller 41b detects the generation state of the near-field light R based on the light intensity measured by the measurement unit 41a, and operates the polarization adjustment mechanism 6.

A case where the polarization direction is adjusted by the information recording / reproducing apparatus 40 configured as described above will be described.
First, as shown in FIGS. 10 and 11, the near-field light R is generated by operating the optical signal controller 5 when the near-field light head 2 is retracted to the lamp mechanism 42. Then, the measuring unit 41a measures the light intensity of the near-field light R generated from the near-field light generating element 21, and outputs the measurement result to the polarization controller 41b. Here, when the polarization direction of the laser light L incident on the near-field light generating element 21 is substantially coincident with a predetermined direction, a light intensity sufficient for recording is measured. On the other hand, when the polarization direction of the laser beam L is significantly deviated from a predetermined direction, a weak light intensity insufficient for recording or a light intensity close to zero is measured. Thus, by measuring the light intensity, it is possible to detect the generation state of the near-field light R.

The polarization controller 41b then determines how much the polarization direction of the laser light L actually incident on the near-field light generating element 21 is based on the light intensity measured by the measurement unit 41a with respect to a predetermined direction. It is possible to grasp whether it is shifted. Then, the polarization controller 41b operates the polarization adjusting mechanism 6 so that at least near-field light R having a light intensity necessary for recording information is generated.
As a result, as in the first embodiment, the polarization direction of the laser light L can be guided to the near-field light generating element 21 as close as possible to a predetermined direction, and at least necessary for recording information. Near-field light R with light intensity can be generated.
In particular, since the measuring unit 41a can be attached to the generally used lamp mechanism 42, it is not necessary to secure an installation space for the measuring unit 41a. In addition, unlike the first embodiment, since it is not necessary to testly record the disk D, it is more preferable.

  In the second embodiment, when the polarization controller 41b operates the polarization adjustment mechanism 6, the half-wave plate 6a may be rotated by a designated rotation angle (correction value). You may operate | move, performing feedback control. Here, the case where each of the two patterns is operated will be briefly described.

First, a case where the half-wave plate 6a is rotated by a designated rotation angle will be described.
In this case, the light intensity measured by the measurement unit 41a is compared with a preset light intensity threshold, and if the measured light intensity is lower than the threshold, the difference is canceled out. The polarization controller 41b may be set so that the polarization adjustment mechanism 6 is operated so that the polarization angle is rotated by the calculated rotation angle.

  With this setting, when the polarization controller 41b operates the polarization adjustment mechanism 6, first, the light intensity measured by the measurement unit 41a is compared with a preset light intensity threshold. At this time, if the measured light intensity is larger than the threshold value, the polarization controller 41b determines that the near-field light R having a light intensity sufficient to record information is generated, and the polarization adjustment mechanism 6 Do not operate. On the other hand, when the measured light intensity is lower than the threshold value, the polarization controller 41b determines that the near-field light R having a light intensity sufficient for recording information is not generated, and causes the polarization adjustment mechanism 6 to operate. Operate. At this time, the polarization controller 41b calculates a rotation angle that cancels the difference between the measured light intensity and the threshold value, and sets the polarization adjustment mechanism 6 so that the half-wave plate 6a rotates by the calculated rotation angle. Operate. Thereby, the polarization direction of the laser beam L is rotated by this rotation angle, and the polarization direction is changed. As a result, it is possible to reliably generate near-field light R having a light intensity necessary for recording at least information.

Next, the case where the polarization adjustment mechanism 6 is operated while performing feedback control will be described.
In this case, the polarization controller 41b may be set so that the polarization adjustment mechanism 6 is operated while performing feedback control so that the light intensity measured by the measurement unit 41a matches a preset light intensity threshold. .
By setting in this way, when the polarization controller 41b operates the polarization adjustment mechanism 6, the half-wave plate 6a is rotated while performing feedback control so that the measured light intensity matches the threshold value. As a result, the polarization direction can be adjusted with higher accuracy, and similarly, near-field light R having a light intensity necessary for recording information can be reliably generated.

In the second embodiment, the polarization controller 41b may operate the polarization adjustment mechanism 6 so that the light intensity measured by the measurement unit 41a is maximized.
In this case, the polarization controller 41b operates the polarization adjusting mechanism 6 by rotating the half-wave plate 6a so that the light intensity is maximized, not at least the minimum light intensity necessary for recording information. In other words, the polarization adjusting mechanism 6 is operated so that the polarization direction of the laser light L matches the predetermined direction. By doing so, the light intensity of the near-field light R can be maximized, so that information can be recorded more stably and high-density recording can be achieved.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in each of the above embodiments, the minute opening 37 constituting the near-field light generating element 21 has a triangular shape, but is not limited to this shape. For example, as shown in FIG. 12, two triangular micro openings 37 may be formed so as to face each other with their vertices abutted. In this case, since the near-field light R can be concentrated and concentrated at the abutted vertex, high-density recording can be achieved similarly. Even in this case, it is preferable that the laser beam L is incident so that the polarization direction is in the direction of the arrow P1.

  Further, as shown in FIG. 13, a minute scatterer 43 that scatters the laser light L may be formed in a minute opening 37 formed in a square shape. The minute scatterer 43 is formed, for example, in a rectangular shape by vapor deposition or film formation at a substantial center of the minute opening 37. By doing so, the near-field light R can be concentrated and localized in the vicinity of the minute scatterer 43, so that high-density recording can be similarly achieved. In this case, it is preferable that the laser beam L is incident so that the polarization direction is in the direction of the arrow P1 or the direction of the arrow P2 orthogonal to the P1 direction.

  Furthermore, as shown in FIG. 14, it may be a minute opening 37 formed in a C shape. By doing so, the near-field light R can be concentrated and concentrated at the approximate center of the minute opening 37, so that high-density recording can be similarly achieved. Even in this case, it is preferable that the laser beam L is incident so that the polarization direction is in the direction of the arrow P1.

Further, in each of the above embodiments, the optical waveguide 4 is connected to the near-field optical head 2 in a state where the distal end side of the optical waveguide 4 is bent by approximately 90 degrees. However, the connection of the optical waveguide 4 is not limited to this case. For example, as shown in FIG. 15, the laser light L may be guided to the light flux propagation element 35 in a state where the optical waveguide 4 is disposed substantially parallel to the near-field light head 2. Even in this case, the same effects can be achieved. In particular, the optical waveguide 4 may not be fixed to the upper surface of the beam 3.
In each of the above embodiments, the polarization adjusting mechanism 6 is fixed adjacent to the optical signal controller 5, but is not limited to this position, and can be placed between the optical signal controller 5 and the near-field optical head 2. It only has to be interposed in the middle of the optical waveguide 4. For example, as shown in FIG. 16, it may be fixed to the upper surface of the beam 3. Even in this case, the same effects can be achieved.

  Moreover, in each said embodiment, you may set so that the polarization direction of the laser beam L may be adjusted suitably at the timing which a user desires. By doing so, the reliability of information writing can be further stabilized.

  In the above embodiments, the case where the polarization adjusting mechanism 6 adjusts the polarization direction of the laser light L using the half-wave plate 6a has been described as an example. However, the present invention is not limited to this case. For example, the adjustment may be performed using a magneto-optical element that can change the polarization direction only while a voltage is applied, and the middle of the optical waveguide 4 is configured to be partially rotatable. You may make it adjust a polarization direction by rotating.

In each of the above embodiments, the case where the laser light L incident in the optical waveguide 4 in the state of linear polarization is guided to the near-field optical head 2 while being linearly polarized has been described as an example. 6 may be configured to guide the near-field light head 2 with the laser light L that has been elliptically polarized by 6 and adjusted so that the elliptical direction is in the optimum direction. Even in this case, the polarization state of the laser light L can be optimized, and the same effect can be obtained.
Further, even if the polarization of the laser light L becomes elliptically polarized before reaching the polarization adjusting mechanism 6 due to the bending state of the optical waveguide 4, the elliptical azimuth can be appropriately adjusted by the polarization adjusting mechanism 6, so that it is optimal. A laser beam L in a polarized state can be guided to the near-field light head 2. Therefore, even in such a case, information can be stably written.

In each of the above embodiments, the air-floating type information recording / reproducing apparatus in which the near-field light head 2 is levitated has been described as an example. The disk D and the slider 20 may be in contact with each other. That is, the near-field optical head 2 of the contact slider 20 type may be used. Even in this case, the same effects can be achieved.
In each of the above embodiments, the information recording / reproducing apparatus of the perpendicular magnetic recording system has been described as an example. However, the present invention is not limited to this, and the recording magnetization is recorded in the direction parallel to the track of the disk D (in-plane direction). The information recording / reproducing apparatus of the in-plane recording method may be used.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows 1st Embodiment which concerns on this invention, Comprising: It is a whole block diagram of an information recording / reproducing apparatus. It is a perspective view of the beam shown in FIG. 1, Comprising: It is a perspective view of the state which turned the near-field light head downward. It is a perspective view of the beam shown in FIG. 1, Comprising: It is a perspective view of the state which orient | assigned the near-field optical head upwards. FIG. 2 is a cross-sectional view of the beam tip shown in FIG. 1, with the near-field optical head facing upward. It is a figure which shows the cross section of the near-field optical head shown in FIG. 1, and the relationship between a near-field optical head and each component. FIG. 6 is a plan view of the near-field light generating element of the near-field light head shown in FIG. 5 as viewed from the disk side. FIG. 3 is a cross-sectional arrow view AA shown in FIG. It is a perspective view of the half-wave plate which the polarization adjustment mechanism shown in FIG. 1 has. It is a figure which shows 2nd Embodiment which concerns on this invention, Comprising: It is a whole block diagram of an information recording / reproducing apparatus. FIG. 10 is a diagram illustrating a state in which the beam is moved from the state illustrated in FIG. 9 and the near-field optical head is retracted from the disk. FIG. 10 is a diagram illustrating a cross-section of the near-field light head illustrated in FIG. 9 and a relationship between the near-field light head and each component. It is a figure which shows the modification of the near-field light generating element shown in FIG. 6, Comprising: It is a figure which shows the near-field light generating element in which two triangular openings were formed in the state which face | matched the vertex. It is a figure which shows the modification of the near-field light generating element shown in FIG. 6, Comprising: It is a figure which shows the near-field light generating element which has the minute opening in which the metal scatterer was formed in the approximate center. It is a figure which shows the modification of the near-field light generating element shown in FIG. 6, Comprising: It is a figure which shows the near-field light generating element which has a C-shaped minute opening. It is a figure which shows the modification of the information recording / reproducing apparatus which concerns on this invention, Comprising: It is a partial block diagram of the information recording / reproducing apparatus which introduces a laser beam with the optical waveguide arrange | positioned substantially parallel to the near-field optical head. It is a figure which shows the modification of the information recording / reproducing apparatus based on this invention, Comprising: It is a perspective view of the beam by which the polarization adjustment mechanism was fixed to the upper surface.

Explanation of symbols

D ... Disk (magnetic recording medium)
D1 ... disk surface (surface of magnetic recording medium)
L ... Laser beam (light beam)
R: Near-field light 1, 40 ... Information recording / reproducing apparatus 2 ... Near-field light head 3 ... Beam 4 ... Optical waveguide 5 ... Optical signal controller (light source)
6 ... Polarization adjustment mechanism 7, 41 ... Control mechanism 8 ... Actuator 9 ... Spindle motor (rotation drive unit)
DESCRIPTION OF SYMBOLS 10 ... Control part 20 ... Slider 21 ... Near field light generation element 22 ... Recording element 23 ... Reproduction element 41a ... Measurement part 41b ... Polarization controller

Claims (7)

An information recording / reproducing apparatus for recording / reproducing information on / from a magnetic recording medium rotating in a fixed direction using near-field light,
A slider opposed to the surface of the magnetic recording medium; a near-field light generating element for generating the near-field light from the introduced light beam; and a recording element for recording information by applying a recording magnetic field to the magnetic recording medium And a reproducing element for reproducing information by outputting an electric signal corresponding to the magnitude of the magnetic field leaked from the magnetic recording medium, and a near-field optical head,
A beam that is movable in a direction parallel to the surface of the magnetic recording medium, and that supports the near-field optical head in a state of being rotatable about two axes parallel to the surface of the magnetic recording medium and orthogonal to each other;
A flexible optical waveguide having a tip connected to the near-field optical head to guide the light flux to the near-field optical head;
A light source connected to a proximal end side of the optical waveguide, and causing the light beam to enter the optical waveguide in a linearly polarized state;
A polarization adjustment mechanism that adjusts the polarization of the light beam that is interposed in the middle of the optical waveguide between the light source and the near-field optical head and travels in the optical waveguide;
The generation state of the near-field light generated from the near-field light generating element is detected, and the polarization adjusting mechanism is operated in accordance with the detection to generate near-field light having at least a light intensity necessary for information recording. A control mechanism to generate,
An actuator for supporting the base end side of the beam and moving the beam in a direction parallel to the surface of the magnetic recording medium;
A rotation drive unit for rotating the magnetic recording medium in the fixed direction;
An information recording / reproducing apparatus comprising: a control unit that operates the control mechanism to perform polarization adjustment at least before starting the recording of the information. The information recording / reproducing apparatus according to claim 1,
The control mechanism detects the generation state of the near-field light by operating the recording element and the light source on a trial basis and detecting whether or not the information is actually recorded. Recording / playback device. The information recording / reproducing apparatus according to claim 1,
The control mechanism is disposed adjacent to the magnetic recording medium and measures a light intensity of the near-field light generated from the near-field light generating element;
An information recording / reproducing apparatus comprising: a polarization controller that operates the polarization adjustment mechanism based on the light intensity measured by the measurement unit. The information recording / reproducing apparatus according to claim 3,
The information recording / reproducing apparatus, wherein the polarization controller operates the polarization adjustment mechanism so that the light intensity measured by the measurement unit is maximized. The information recording / reproducing apparatus according to claim 3 or 4,
The polarization controller compares the light intensity measured by the measurement unit with a preset light intensity threshold, and cancels the difference if the measured light intensity is lower than the threshold. An information recording / reproducing apparatus that calculates a correction value and operates the polarization adjusting mechanism by the calculated correction value. The information recording / reproducing apparatus according to claim 3 or 4,
The information recording / reproducing apparatus, wherein the polarization controller operates the polarization adjusting mechanism while performing feedback control so that the light intensity measured by the measurement unit matches a preset light intensity threshold value. The information recording / reproducing apparatus according to any one of claims 1 to 6,
The polarization adjustment mechanism adjusts the polarization direction by rotating the polarization direction of the light beam incident in a linearly polarized state around the axis of the optical waveguide, and causes the light to enter the near-field optical head as linearly polarized light. A characteristic information recording / reproducing apparatus.

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