JP3895458B2 - Near-field optical head - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical memory head that reproduces and records high-density information using near-field light.
[0002]
[Prior art]
A scanning probe microscope (SPM) typified by a scanning tunneling microscope (STM) or an atomic force microscope (AFM) is used to observe a minute region on the order of nanometers on the sample surface. SPM scans a sample surface with a probe with a sharpened tip, and observes the interaction between the probe and the sample surface, such as tunneling current and atomic force, with an image of resolution depending on the probe tip shape. However, restrictions on the sample to be observed are relatively severe.
[0003]
Therefore, near-field optical microscopes that are capable of observing minute areas on the sample surface by focusing on the interaction between the near-field light generated on the sample surface and the probe are drawing attention. .
In a near-field optical microscope, the near-field light is generated by irradiating the surface of the sample with propagating light, and the generated near-field light is scattered by a probe with a sharpened tip. By processing in the same manner as the detection, the limit of the observation resolution by the conventional optical microscope is overcome, and it is possible to observe a finer region. In addition, it is possible to observe the optical properties of the sample in a minute region by sweeping the wavelength of the light applied to the sample surface.
[0004]
In addition to being used as a microscope, by introducing relatively high intensity light toward the sample through the optical fiber probe, near-field light with high energy density is generated at the microscopic aperture of the optical fiber probe, and the sample is generated by the near-field light. Application as high-density optical memory recording in which the surface structure or physical properties are locally changed is also possible.
[0005]
As a probe used in a near-field optical microscope, for example, as disclosed in US Pat. No. 5,294,790, an opening is formed in a silicon substrate by a semiconductor manufacturing technique such as photolithography, and one of the silicon substrates is formed. There has been proposed a cantilever type optical probe in which an insulating film is formed on the surface and a conical optical waveguide layer is formed on the insulating film opposite to the opening. In this cantilever type optical probe, light can be transmitted through a minute opening formed by inserting an optical fiber into the opening and coating the portion other than the tip of the optical waveguide layer with a metal film.
[0006]
Furthermore, it has been proposed to use a planar probe that does not have a sharpened tip like the above-described probe. The planar probe is formed by forming an opening of an inverted pyramid structure on a silicon substrate by anisotropic etching, and its apex is penetrated with a diameter of several tens of nanometers. A plurality of such planar probes can be formed on the same substrate using semiconductor manufacturing technology, that is, can be easily arrayed, and can be used as an optical memory head suitable for reproducing and recording an optical memory using near-field light. . As an optical head using this flat probe, a flying head conventionally used in a hard disk has been proposed which has a flat probe.
[0007]
The flying head is aerodynamically designed to fly about 50 to 100 nm from the recording medium. By forming a minute opening on the recording medium side of this flying head, it is possible to generate near-field light and perform optical recording and reproduction.
On the other hand, in order to increase the density of the conventional hard disk, it is necessary to make the distance between the magnetic head and the recording medium close. As one approach method, a contact slider has been devised. The contact slider is brought into contact with the recording medium with three contact pads, and one of the contact pads has a magnetic head.
[0008]
Therefore, the recording medium and the magnetic head can always be brought into contact with each other, and high-density magnetic recording is possible.
Further, since the recording pit size decreases as the recording density increases, the head is required to have high positioning accuracy. In positioning the head of the hard disk, there is a slider at the tip of a suspension of several tens of mm connected to the servo motor, and the slider moves to the left and right with respect to the track direction. However, in a conventional servo system having a heavy slider at the end of a long suspension, the generated moment of inertia is large and the resonance frequency is small, so that high-speed and high-precision positioning is difficult. As a solution to this problem, a two-stage servo has been proposed for hard disks. The two-stage servo has a second-stage actuator that moves the entire slider minutely at the tip of the suspension. The distance between the second-stage actuator and the slider is shortened to about several hundreds μm, and the inertia applied to the second-stage actuator is reduced. Attempts have been made to enable high-speed and high-accuracy positioning by reducing the moment and increasing the resonance frequency.
[0009]
[Problems to be solved by the invention]
However, the intensity of near-field light decays exponentially with distance from its source. Therefore, the intensity of near-field light emitted from the microscopic aperture of the planar probe formed on the flying head is very small because the planar probe is away from the recording medium. In addition, there is a problem that the variation in the intensity of near-field light increases due to the variation in the flying height. Furthermore, the farther the minute aperture is from the recording medium, the larger the spot diameter at which near-field light irradiates the recording medium. Therefore, it is difficult to increase the recording density. Further, a probe with a sharpened tip has a problem that it is easily broken by contact with an observation sample or a recording medium.
[0010]
In addition, although the distance from the actuator portion to the recording / reproducing element is short, the two-stage servo in the hard disk has a problem that a large inertia force is generated and the resonance frequency is low because the entire slider having a large mass is moved. is doing.
Therefore, the present invention always provides an optical recording / reproducing element that has sufficient strength to withstand contact with a recording medium and generates near-field light in order to realize information recording / reproduction of an optical memory using near-field light. By making contact with the recording medium, near-field light having a high intensity and a small spot diameter can be used, and at the same time, the optical recording / reproducing element is finely moved by an actuator formed in the vicinity of the light-weight optical recording / reproducing element. Thus, an object of the present invention is to provide an optical head capable of high-speed and high-precision positioning.
[0011]
It is another object of the present invention to provide a near-field optical head that can reduce the size of an information recording apparatus.
[0012]
[Means for Solving the Problems]
To achieve the above object, a near-field optical head according to the present invention includes a slider, a swing mechanism formed on the slider, and an optical recording / reproducing having a minute aperture formed on the swing mechanism. In a near-field optical head comprising an element and two contact elements formed on the slider, the near-field optical head is in contact with a recording medium at three points: the optical recording / reproducing element and the two contact elements. In addition, the near-field optical head is characterized in that the optical recording / reproducing element is finely moved by the swing mechanism.
[0013]
Therefore, the near-field optical head according to the present invention has a high density because the minute aperture is always in contact with the recording medium, the intensity of the near-field light irradiated from the minute aperture to the recording medium is large, and the spot diameter is small. Recording and playback is possible. In addition, since a light-weight optical recording / reproducing element is finely moved by a swing mechanism formed in the vicinity thereof, high-speed and high-precision tracking is possible.
[0014]
In addition, the near-field optical head according to the present invention includes a slider, two contact elements formed on the slider, a fine movement mechanism formed on the slider, and a minute opening formed on the fine movement mechanism. The near-field optical head is in contact with the recording medium at three points: the optical recording / reproducing element and the two contact elements, and the optical recording / reproducing element is The near-field optical head is characterized by being finely moved by a fine movement mechanism.
[0015]
Therefore, the near-field optical head according to the present invention has a high density because the minute aperture is always in contact with the recording medium, the intensity of the near-field light irradiated from the minute aperture to the recording medium is large, and the spot diameter is small. Recording and playback is possible. In addition, since a light-weight optical recording / reproducing element is finely moved by a swing mechanism formed in the vicinity thereof, high-speed and high-precision tracking is possible.
[0016]
Further, the near-field optical head according to the present invention includes a slider, at least two beams extending from the slider, the beam selection mechanism formed on each of the beams, and each of the beams. The selection includes: a swing mechanism or a fine movement mechanism; an optical recording / reproducing element having a minute aperture formed on the swing mechanism or the fine movement mechanism; and the two contact elements formed on the slider. By selectively bending one beam to the recording medium side by a mechanism, the recording medium is brought into contact with the two contact elements and the optical recording / reproducing element on the selected beam at three points. In addition, the near-field optical head is characterized in that the optical recording / reproducing element is finely moved by the swing mechanism and the fine movement mechanism.
[0017]
Therefore, the near-field optical head according to the present invention has a high density because the minute aperture is always in contact with the recording medium, the intensity of the near-field light irradiated from the minute aperture to the recording medium is large, and the spot diameter is small. Recording and playback is possible. Also, by selecting the optical recording / reproducing element, it is possible to perform recording and reproduction on a plurality of recording tracks on the recording medium without moving the slider. Even if one of the optical recording / reproducing elements is damaged, the other optical recording / reproducing elements can be used, so that the life of the near-field optical head can be extended.
[0018]
In the near-field optical head according to the present invention, the swing mechanism includes a beam extending from the slider and a piezoelectric element formed on the beam. The piezoelectric element is expanded and contracted to expand and contract the beam. The near-field optical head is characterized by bending and finely moving the optical recording / reproducing element.
Therefore, since the optical recording / reproducing element is finely moved by the piezoelectric element disposed in the vicinity of the light optical recording / reproducing element, high-speed and high-accuracy tracking is possible.
[0019]
In the near-field optical head according to the present invention, the swinging mechanism is formed on a beam extending from the slider, a conductive region formed on a side surface of the beam, and a surface facing the conductive region. The near-field optical head has a conductive region, wherein the beam is bent by generating an electrostatic force between the two conductive regions, and the optical recording / reproducing element is finely moved.
[0020]
Accordingly, since the interval between the conductive regions is very narrow, the optical recording / reproducing element can be finely moved with low power, and high-speed and high-accuracy tracking is possible.
In the near-field optical head according to the present invention, the oscillating mechanism uses a rotating mechanism to reciprocate an arc, and the optical recording / reproducing element has the minute aperture that is rotated by the rotating mechanism. The near-field optical head is characterized in that the optical recording / reproducing element is finely moved by being arranged at a position eccentric with respect to the axis.
[0021]
Therefore, since the near-field optical head has the swing mechanism integrated on the slider, the rigidity is high and the resonance frequency is high, so that higher-speed and high-precision tracking is possible.
A near-field optical head according to the present invention is characterized in that the fine movement mechanism is a piezoelectric element, and the optical recording / reproducing element is finely moved by expanding and contracting the piezoelectric element; did.
[0022]
Therefore, since the piezoelectric element directly finely moves the light optical recording / reproducing element, tracking with higher speed and higher accuracy is possible.
In the near-field optical head according to the present invention, the selection mechanism is a piezoelectric element, and the beam is bent toward the recording medium by expanding and contracting the piezoelectric element. It was.
[0023]
Therefore, it is possible to select the optical recording / reproducing element in contact with the recording medium.
In the near-field optical head according to the present invention, the selection mechanism includes a conductive region formed on a surface of the beam and a conductive region formed on a surface facing the conductive region. The near-field optical head is characterized in that the beam is bent toward the recording medium by generating an electrostatic force between the regions.
[0024]
Therefore, it is possible to select the optical recording / reproducing element in contact with the recording medium.
The near-field optical head according to the present invention is a near-field optical head characterized in that the near-field optical head has a light receiving element.
Therefore, since a condensing lens system and an external light receiving element are unnecessary, the information recording / reproducing apparatus can be downsized.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
[Embodiment 1]
FIG. 1 shows a view of the optical head 101 according to Embodiment 1 as viewed from the side in contact with the recording medium.
The slider 3 of the optical head 101 has two beams 4. This beam 4 forms a triangular structure. The triangular structure constituted by the beams 4 has the optical recording / reproducing element 1 at the apex portion. Each beam 4 forming a triangular structure has a piezoelectric element 5 on the surface of the recording medium. Further, the piezoelectric element 5 may be arranged on the surface of the beam 4 opposite to the recording medium side. Further, the piezoelectric element 5 can be arranged on both the recording medium side and the opposite side of the beam 4. The slider 3 has two contact elements 2 with the recording medium.
[0026]
The beam 4 has a length of, for example, several tens of μm. The optical recording / reproducing element 1 and the contact element 2 have a height of several tens of μm from the slider surface, for example.
According to this structure, when the optical head 101 is pressed against a flat recording medium by a suspension 111 (to be described later), the optical head 101 comes into contact with the recording medium at three points: the optical recording / reproducing element 1 and the two contact elements 2. Further, the optical head 101 follows the out-of-plane vibration of the rotating recording medium by the optical recording / reproducing element 1 and the contact element 2 having a contact area optimally designed as will be described later. Further, the optical recording / reproducing element 1 and the contact element 2 have sufficient strength to withstand contact with the recording medium. Therefore, the optical head 101 is always in contact with the recording medium at three points. That is, with the above structure, the optical recording / reproducing element 1 is always kept in contact with the recording medium.
[0027]
Further, the beam 4 is fixed to the slider 3 by applying a voltage so that one of the piezoelectric elements 5 formed on the two beams 4 expands, and simultaneously applying a voltage so that the other piezoelectric element 5 contracts. Move left and right around the point. At this time, the optical recording / reproducing element 1 having a triangular structure constituted by the beams 4 moves in the left-right direction with respect to the track direction 14 in which the information signal on the recording medium is recorded. The amount of movement of the optical recording / reproducing element 1 depends on the length of the beam and the size of the piezoelectric element 5, and is several hundred nm, for example. Further, the resolution of the movement amount of the optical recording / reproducing element 1 can be, for example, 10 nm or less. In addition, the optical head 101 shown in FIG. 1 can move the lightweight optical recording / reproducing element 1 with the piezoelectric element 5 arranged in the very vicinity, so that high-speed and high-accuracy tracking is possible.
[0028]
The optical recording / reproducing element 1 can also be moved by forming the optical recording / reproducing element 1 at the tip of one beam 4 and forming the piezoelectric element 5 on the side surface of the beam 4. However, it is very difficult to form the piezoelectric element 5 on the side surface of the beam 4. According to the configuration shown in FIG. 1, since the triangular structure is formed by the two beams 4 and the piezoelectric element 5 is formed on the upper surface of the two beams 4, the optical head 101 can be easily manufactured. Furthermore, compared to the case of only one beam 4, the triangular structure is formed by the two beams 4, so that the rigidity of the mechanism part that drives the optical recording / reproducing element 1 is increased and high-precision tracking is possible. It becomes.
[0029]
FIG. 2 is an enlarged view of the optical recording / reproducing element 1, and FIG. 12 is a sectional view thereof.
The optical recording / reproducing element 1 has a tapered shape and has a flat surface 13 at the apex portion thereof. Further, the contact element 2 has a similar outer shape. The plane 13 has a minute aperture 6 that generates near-field light. The minute opening 6 is formed by a tapered cavity formed so as to penetrate the flat surface 13 of the apex portion. The size of the cavity near the minute aperture is smaller than the wavelength of light. Therefore, when the reflectivity of the inner wall of the cavity near the minute aperture is low, the intensity of near-field light generated from the minute aperture 6 is lowered. In order to solve this problem, a reflection film 7 having a high reflectance is formed on the inner wall of the cavity near the minute opening. If the sum of the areas of the flat surface 13 and the contact element 2 in contact with the recording medium is large, there arises a problem that the optical head 101 is attracted to the recording medium and does not move. In addition, if the sum of the areas of the flat surface 13 and the contact element 2 in contact with the recording medium is too small, the adsorption force with the recording medium is weakened, and the optical head 101 cannot follow the out-of-plane vibration of the recording medium. The distance between the reproducing element 1 and the recording medium varies. Further, the wear rates of the optical recording / reproducing element 1 and the contact element 2 differ depending on the sum of the areas of the flat surface 13 and the contact element 2 in contact with the recording medium and the pressing force of the optical head 101 against the recording medium. In consideration of the above, the areas of the flat surface 13 and the contact element 2 that are in contact with the recording medium have optimum designed values. In a general design, the sum of the areas in contact with the recording medium of the plane 13 and the contact element 2 is, for example, several tens to several hundreds μm. ² It is. Further, the minute aperture 6 has a diameter of, for example, 10 to 200 nm smaller than the wavelength of propagating light to be used, and is externally constricted by a condensing lens system not shown in the drawing from the side opposite to the recording medium. Near-field light is generated from the microscopic aperture 6 by irradiating the microscopic aperture 6 with the propagating light from the light source following the movement of the optical recording / reproducing element 1.
[0030]
The shape of the optical head 101 according to the first embodiment of the present invention is formed by a conventional semiconductor process. For example, the outer shape of the optical recording / reproducing element 1 and the contact element 2 are formed on single crystal silicon by anisotropic etching with potassium hydroxide. Next, anisotropic etching with potassium hydroxide is performed from the surface opposite to the side on which the optical recording / reproducing element 1 and the contact element 2 are formed, and a taper is formed so as to penetrate the plane of the apex portion of the optical recording / reproducing element 1. By forming the cavity, the micro opening 6 is formed. The reflective film 7 is a metal having a high reflectivity such as Al, Au / Cr (having Au formed on Cr), and is formed by sputtering or vacuum evaporation. Thereafter, an etching mask for obtaining the shapes of the slider 3 and the beam 4 is formed, and dry etching such as reactive ion etching (hereinafter abbreviated as RIE) or anisotropic wet etching using potassium hydroxide (KOH) or the like is performed. The slider 3 and the beam 4 are formed. The piezoelectric element 5 is formed on the beam 4 by sputtering or bonding.
[0031]
FIG. 5 is a diagram showing a simple device configuration of the optical recording / reproducing apparatus.
A method will be described in which the near-field optical memory head 101 described above is arranged on the recording medium 103 and information recording and reproduction are performed using near-field light emitted from a minute aperture.
The optical head 101 is in contact with the recording medium 103 at three points: the optical recording / reproducing element 1 and the two contact elements 2. The recording medium 103 is rotated by a recording medium driving motor 104. The recording medium 103 is, for example, a phase change recording medium in which an amorphous state or a crystalline state is obtained by applying heat, and recording / reproduction is performed using a difference in reflectance or transmittance. In this case, for example, information recording is performed by irradiating the recording medium with near-field light generated from a minute aperture, thereby changing the region irradiated with the near-field light on the recording medium from a crystalline state to an amorphous state. Is called. Since the optical recording / reproducing element 1 is always in contact with the recording medium 103, the size of the near-field light applied to the recording medium is the same as that of the minute aperture, and has a diameter of, for example, 100 nm. Near-field light attenuates exponentially with respect to the distance from the minute aperture. Since the optical recording / reproducing element 1 is always in contact with the recording medium, the present optical head 101 is irradiated on the recording medium 103 as compared with near-field light irradiated from a planar probe formed on the flying head. Near-field light has a very high intensity. Accordingly, the near-field light irradiated to the recording medium from the minute aperture of the optical recording / reproducing element 1 has a large intensity and a small spot diameter, so that the size of the recording pit is, for example, a diameter of 100 nm or less. Therefore, the optical head 101 shown in FIG. 1 can easily perform high-density recording.
[0032]
On the other hand, information reproduction is performed as described below, for example. First, the control circuit 107 of the optical head 101 sends a signal to the primary servo drive circuit 109 so that the minute aperture moves to a desired information recording position. The primary servo motor 102 that has received a signal from the primary servo drive circuit 109 moves the entire optical head 101 via the suspension 111, and moves the minute aperture to the vicinity of the information recording position. Next, near-field light is irradiated onto the recording pit from the minute aperture, and the propagating light transmitted through the recording medium 103 is collected on the light receiving element 106 by the condenser lens system 105 to obtain an information signal. The obtained information signal is sent to the control circuit 107 and, for example, the signal intensity is compared to detect the positional deviation between the minute aperture and the recording pit. When the position of the minute opening and the recording pit is shifted, a signal is sent from the control circuit 107 to the secondary servo circuit 108 so as to correct the position shift, and the secondary servo circuit drives the secondary servo actuator. The secondary servo actuator is, for example, the piezoelectric element 5 shown in FIG. The propagating light transmitted through the recording medium 103 is condensed on the light receiving element including the difference in transmittance between the amorphous state and the crystalline state of the recording medium, for example. Information on the difference in transmittance is detected as an information signal. The obtained information signal is converted into a reproduction signal through a signal processing circuit not shown in the figure.
[0033]
As described above, according to the first embodiment, the optical head 101 pressed by the suspension 111 is always in contact with the recording medium at three points having the optimally designed contact area including the optical recording / reproducing element 1. Since the recording medium can be irradiated with near-field light having a high intensity and a small spot diameter from the minute aperture 6 formed in the optical recording / reproducing element 1, the optical head 101 capable of high-density recording / reproducing can be provided.
[0034]
Further, since the light-weight optical recording / reproducing element 1 formed on the highly rigid triangular beam 4 can be moved with high speed and high precision by the piezoelectric element 5 arranged in the very vicinity thereof, tracking with high followability is possible. The optical head 101 capable of performing the above can be provided.
Furthermore, since the optical head according to the present invention can be formed using a semiconductor process, the optical head 101 is suitable for mass production, has uniform performance, and is inexpensive.
[0035]
[Embodiment 2]
FIG. 3 is a sectional view of the optical recording / reproducing element 1 according to the second embodiment.
The optical recording / reproducing element 1 according to the second embodiment has the same shape as the optical recording / reproducing element 1 shown in FIG. The difference is that the optical waveguide 8 is formed on the surface opposite to the surface on which the optical recording / reproducing element 1 is formed.
[0036]
For example, the optical waveguide 8 made of an optical fiber is formed so that propagating light is irradiated to the minute opening 6. An external light source (not shown) is coupled to the incident end of the optical waveguide 8, propagates through the optical waveguide 8, and irradiates the microscopic aperture 6 with the propagating light from the other end. Field light is generated. The optical waveguide 8 is fixed to the beam 4. Therefore, when the optical recording / reproducing element 1 is moved, the relative position between the minute aperture 6 and the emission end of the optical waveguide 8 does not change.
[0037]
The optical recording / reproducing element 1 according to the second embodiment of the present invention is manufactured by almost the same process as that of the first embodiment. The difference from the first embodiment is that the optical waveguide 8 is formed by bonding or bonding after all the steps described in the first embodiment are completed.
As described above, according to the second embodiment, in addition to the effects described in the first embodiment, by using the optical waveguide 8, the propagation light from the external light source is used for the movement of the optical recording / reproducing element 1. Since the following optical system is not required, the optical head 101 having the effect of facilitating the downsizing of the recording / reproducing apparatus in FIG. 5 can be provided.
[0038]
[Embodiment 3]
FIG. 4 is a sectional view of the optical recording / reproducing element 1 according to the third embodiment.
The structure of the optical recording / reproducing element 1 is the same as that shown in FIG. However, the beam 4 has a light emitting element 9 such as a semiconductor laser or a light emitting diode at the bottom of the cavity forming the minute opening 6 as a light source for irradiating the minute opening 6 with propagating light. The light emitting element 9 is formed so as to completely cover the bottom of the cavity that forms the minute opening 6.
[0039]
The optical recording / reproducing element 1 of the third embodiment is manufactured by almost the same process as that of the first embodiment. The difference from the first embodiment is that the light emitting element 9 is formed by adhesion or bonding after all the steps described in the first embodiment are completed.
According to the third embodiment of the present invention, in addition to the effects of the optical recording / reproducing element 1 in the second embodiment, the following effects can be obtained. Compared to the second embodiment, the distance from the light source is short, and there is no loss of light when the propagating light is coupled to the optical waveguide 8 or in the bent portion of the optical waveguide 8 in FIG. The intensity of the field light becomes stronger. In addition, since an external light source is not required, the recording / reproducing apparatus is downsized. Since the cavity that forms the minute opening 6 can be completely sealed by the light emitting element 9, the light reflected by the reflective film 7 does not leak from the cavity, and light from the vicinity of the optical recording / reproducing element 1 is generated from the minute opening 6. Only near-field light. Therefore, the S / N ratio of the information signal detected by the light receiving element is increased, and it is possible to perform highly reliable reproduction. Furthermore, the semiconductor laser and the light emitting diode are manufactured by a semiconductor process, and the present optical head 101 can also be formed by a semiconductor process. Therefore, the optical head 101 having the optical recording / reproducing element 1 according to the third embodiment is suitable for mass production.
[0040]
Hereinafter, another optical head that can be used in the same apparatus configuration as that of FIG. 5 described in the first embodiment of the present invention will be described in detail.
[Embodiment 4]
FIG. 6 shows the optical head 121 according to the fourth embodiment of the present invention as viewed from the side in contact with the recording medium.
[0041]
The slider 3 of the optical head 121 has a movable beam 15 and two fixed beams 16. The movable beam 15 and the two fixed beams 16 are formed in parallel, and the movable beam 15 is formed between the fixed beams 16. The distance between the movable beam 15 and the fixed beam 16 is, for example, several tens of μm. The fixed beam 16 is formed thicker than the movable beam 15. The tip of the movable beam 15 has an optical recording / reproducing element 1. The slider 3 has two contact elements 2. The fixed beam 16 has the conductive region 10 on the side surface on the movable beam 15 side, and the movable beam 15 has the conductive region 10 on both side surfaces. The optical recording / reproducing element 1 is the same as that described in the first to third embodiments.
[0042]
The conductive regions 10 are insulated from each other, and an electrostatic force is generated by applying a potential between the conductive regions 10 facing each other. By applying a voltage so that an attractive force is generated in one of two conductive regions and applying a voltage so that a repulsive force is generated in the other, the movable beam 15 is bent and the optical recording / reproducing element 1 is moved in the track direction. 14 to the left and right. The amount of movement is, for example, several hundred nm, and the resolution of the amount of movement can be, for example, 10 nm or less. Further, since the lightweight optical recording / reproducing element 1 is moved, the optical recording / reproducing element 1 can be moved at high speed and with high accuracy. Furthermore, the electric power required to deflect the movable beam 15 decreases as the distance between the conductive regions 10 decreases. In this embodiment, the distance between the conductive regions 10 is as small as several tens of μm. The power required to deflect 15 is very small. Therefore, the optical head 121 according to this embodiment can perform high-speed and high-precision tracking with low power.
[0043]
The shape of the optical head 121 described with reference to FIG. 6 of the present invention is formed in substantially the same process as in the first embodiment of the present invention. The difference from the first embodiment of the present invention is the step of forming the conductive region 10 instead of forming the piezoelectric element 5. Conductive region 10 is formed, for example, by ion doping obliquely to beam 4 made of single crystal silicon. The conductive region 10 may be formed by patterning after a metal thin film such as Al or Cr is formed by sputtering or vacuum deposition.
[0044]
As described above, according to the fourth embodiment, in addition to the effects of the optical head 101 in the first embodiment, it is possible to provide the optical head 121 that can drive the optical recording / reproducing element 1 with low power.
[Embodiment 5]
FIG. 7 shows the optical head 131 according to the fifth embodiment of the present invention as viewed from the side in contact with the recording medium.
[0045]
The slider 3 of the optical head 131 has a contact element 2 between one optical recording / reproducing element 1 and two recording media and one rotary actuator 11. The rotary actuator 11 is formed on the slider 3. The optical recording / reproducing element 1 is formed on a rotary actuator 11. The optical recording / reproducing element 1 in this embodiment is the same as the structure of the optical recording / reproducing element 1 in the third embodiment. The minute opening 6 is provided at a position eccentric with respect to the rotation axis of the rotary actuator 11. For example, a rotary actuator that is driven to rotate by electrostatic force is used.
[0046]
Since the minute aperture 6 is in a position eccentric with respect to the rotation axis of the rotary actuator 11, the minute aperture 6 that generates near-field light for recording / reproducing by rotation of the rotary actuator has a track direction 14 on the recording medium. Move to the left and right. The moving amount of the optical recording / reproducing element 1 is, for example, several hundred nm, and the resolution of the moving amount can be 10 nm or less.
[0047]
The shape of the optical head 131 according to the fifth embodiment of the present invention is formed by a conventional semiconductor process. For example, the contact element 2 is formed on single crystal silicon by anisotropic etching using potassium hydroxide. Next, the rotary actuator is formed by RIE. Finally, the optical recording / reproducing element 1 separately produced in the same manner as described above is formed on the rotary actuator by bonding or adhesion. Thereafter, an etching mask for obtaining the shape of the slider 3 is formed, and the slider 3 is formed by dry etching such as RIE or anisotropic wet etching using potassium hydroxide (KOH) or the like.
[0048]
The optical head 131 has the following effects in addition to the effects of the optical head 101 described in FIG. 1 and the optical head 121 described in FIG. The optical head 131 according to the fifth embodiment of the present invention does not have the beam 4 and integrates the mechanism for driving the optical recording / reproducing element 1 on the slider 3. Therefore, since the optical head 131 has higher rigidity than the first and fourth embodiments, it is not easily affected by out-of-plane vibration or external vibration of the rotating recording medium.
[0049]
In the fifth embodiment of the present invention, the optical recording / reproducing element 1 may be one in which the minute opening 6 is formed in the rotary actuator 11. Also in this case, the minute opening 6 is formed at a position eccentric with respect to the rotation axis of the rotary actuator 11.
[Embodiment 6]
FIG. 8 shows a view of the optical head 141 according to the sixth embodiment of the present invention as viewed from the side in contact with the recording medium.
[0050]
The slider 3 of the optical head 141 includes a contact element 2 between one optical recording / reproducing element 1 and two recording media, and at least two piezoelectric elements 5a and 5b. The piezoelectric elements 5 a and 5 b are formed on the slider 3. The optical recording / reproducing element 1 is formed so as to straddle the piezoelectric elements 5a and 5b. The optical recording / reproducing element 1 is the same as in the fifth embodiment. In FIG. 8, a voltage is applied so that the piezoelectric element 5a expands in the direction in which the optical recording / reproducing element 1 is moved, and at the same time, a voltage is applied so as to reduce the piezoelectric element 5b. Can be moved in any direction. Therefore, the optical recording / reproducing element 1 moves to the left and right with respect to the recording track 14 on the recording medium. The moving amount of the optical recording / reproducing element 1 is, for example, several hundred nm, and the resolution of the moving amount can be 10 nm or less. Therefore, highly accurate tracking is possible. According to this structure, the actuator for moving the optical recording / reproducing element 1 is the plate-like piezoelectric element 5 and does not have a complicated structure. Therefore, the optical head 141 of this embodiment has higher rigidity than the optical head 131 of the fifth embodiment of the present invention.
[0051]
The shape of the optical head 141 of the present embodiment can be manufactured by substantially the same process as that of the fifth embodiment of the present invention. The difference is that the step of forming the rotary actuator is a step of forming the piezoelectric element 5 by bonding or sputtering.
As described above, according to the sixth embodiment of the present invention, in addition to the effects of the first embodiment, since it has a simple structure, it can be easily mass-produced, and since it has high rigidity, more accurate tracking is possible. A possible optical head 141 can be provided.
[0052]
[Embodiment 7]
FIG. 9 shows a view of the optical head 151 according to the seventh embodiment of the present invention as viewed from the side in contact with the recording medium.
A plurality of beams 4 extend in parallel from the slider 3 of the optical head 151, and have a piezoelectric element 5 on the tip of each beam 4. The piezoelectric element 5 has a structure similar to that of the sixth embodiment of the present invention. Further, a selection piezoelectric element 17 is provided near the fulcrum on the upper surface of the beam 4 on the recording medium side. The optical head 151 has the optical recording / reproducing element 1 on the piezoelectric element 5. The slider 3 has a contact element 2 with two recording media.
[0053]
By applying a voltage so as to reduce the selected piezoelectric element 17, the beam 4 having the piezoelectric element 17 bends to the recording medium side. Accordingly, by selecting one beam 4, the optical head 151 comes into contact with the recording medium at three points: one optical recording / reproducing element 1 and two contact elements 2. The selection piezoelectric element 17 may be formed on the upper surface of the beam 4 on the side opposite to the recording medium. In this case, the selection of the optical recording / reproducing element 1 in contact with the recording medium is performed by expanding the selection piezoelectric element 17.
[0054]
In the operation method described in the sixth embodiment, the optical recording / reproducing element 1 is moved left and right with respect to the track direction on the recording medium by the piezoelectric element 5. The amount of movement of each optical recording / reproducing element 1 and the resolution of the amount of movement are the same as in the sixth embodiment.
According to this structure, by selecting the optical recording / reproducing element 1 to be brought into contact with the recording medium, recording / reproducing signals can be read / written on a plurality of tracks without largely moving the entire optical head 151. Further, even if one of the optical recording / reproducing elements 1 is damaged, another optical recording / reproducing element 1 can be used, so that the life of the optical head 151 can be extended.
[0055]
The shape of the optical head 151 of this embodiment can be manufactured by the same process as that of the sixth embodiment.
As described above, according to the seventh embodiment of the present invention, in addition to the effect of the sixth example, the optical head 151 is moved greatly by selecting the optical recording / reproducing element 1 to be brought into contact with the recording medium. Therefore, it is possible to record / reproduce on a plurality of tracks, and to perform high-speed recording / reproduction. Furthermore, even if one of the optical recording / reproducing elements 1 is damaged, another optical recording / reproducing element 1 can be used, so that the life of the optical head 151 can be extended.
[0056]
Further, as a mechanism for selecting the optical recording / reproducing element 1 in contact with the recording medium, for example, an electrostatic actuator as shown in FIG. In this case, another beam is formed in parallel to the beam 4 on the side opposite to the recording medium of the beam 4, a conductive region is formed on the surface between the upper and lower beams, and an electric potential is applied to this conductive region, thereby performing optical recording / recording. The optical recording / reproducing element 1 that contacts the recording medium is selected by bending the beam 4 having the reproducing element on the recording medium side.
[0057]
[Embodiment 8]
FIG. 10 is a view of the optical head 110 according to the eighth embodiment of the present invention as viewed from the side in contact with the recording medium.
The structure of the optical head 110 in FIG. 10 is almost the same as that of the optical head 101 in FIG. The difference is that the slider 3 has a light receiving element 12. The distance between the optical recording / reproducing element 1 and the light receiving element 12 is very short, for example, several hundred μm. Therefore, since the scattered light reflected by the recording medium and having a large divergence angle can be efficiently detected by the light receiving element 12, a large signal intensity can be obtained without using a condensing lens system.
[0058]
The shape of the optical head 110 of the present embodiment is almost the same as the method of creating the shape of the optical head 101 according to the first embodiment. The difference is that there is a step of manufacturing the light receiving element 12 before the step of forming the slider 3 and the beam 4. The light receiving element 12 is manufactured by using a semiconductor manufacturing process as in the case of manufacturing a normal light receiving element on the slider 3. Further, a light receiving element may be formed on the slider 3 by bonding or bonding.
[0059]
FIG. 11 shows a simplified diagram of an optical recording apparatus using the optical head 110 in this embodiment.
A method for recording and reproducing information by the near-field light generated in the minute aperture 6 by disposing the optical head 110 described above on the recording medium 103 is substantially the same as that of the first embodiment of the present invention. The method of positioning the optical recording / reproducing element 1 and the method of detecting the information signal at the time of reproducing information are different from the first embodiment. In this embodiment, near-field light generated from the minute aperture 6 is irradiated onto information bits on the recording medium, scattered light is generated, and the scattered light is reflected on the recording medium. By detecting this reflected light with the light receiving element 12 formed on the optical head 110, an information signal is detected. Thus, by detecting the information signal with the light receiving element formed on the optical head 110, the optical recording / reproducing element 1 can be used without using the condensing lens system 105 and the light receiving element 106 in the first embodiment of the present invention. Positioning and information reproduction can be performed.
[0060]
As described above, according to the eighth embodiment, in addition to the effects of the first embodiment, the condenser lens system 105 and the light receiving element 106 are not required. Can provide.
Note that by adding the light receiving element 12 to the optical head 101 of FIGS. 6 to 9, the same effect as that of the optical head 110 of FIG. 10 can be obtained.
[0061]
【The invention's effect】
As described above, according to the first aspect of the invention, the near-field optical head has three points: the optical recording / reproducing element having the contact area with the optimized recording medium and the two contact elements. Since the intensity of near-field light irradiated onto the recording medium from the minute aperture is large and the spot diameter is small, high-density recording is possible. Further, the optical recording / reproducing element and the contact element have a strength sufficient to withstand contact with a recording medium. Furthermore, since a light-weight optical recording / reproducing element is finely moved by a swing mechanism formed in the vicinity thereof, high-speed and high-accuracy tracking is possible. Further, since the near-field optical head of the present invention can be manufactured by a conventional semiconductor process, it can be mass-produced.
[0062]
According to the invention of claim 2, the near-field optical head is always in contact with the recording medium at three points: an optical recording / reproducing element having an optimized contact area with the recording medium and two contact elements. Therefore, high intensity recording is possible because the intensity of near-field light irradiated onto the recording medium from the minute aperture is large and the spot diameter is small. Further, the optical recording / reproducing element and the contact element have a strength sufficient to withstand contact with a recording medium. Furthermore, since a light-weight optical recording / reproducing element is finely moved by a swing mechanism formed in the vicinity thereof, high-speed and high-accuracy tracking is possible. Further, since the near-field optical head of the present invention can be manufactured by a conventional semiconductor process, it can be mass-produced.
[0063]
According to the invention of claim 3, the near-field optical head is always in contact with the recording medium at three points: an optical recording / reproducing element having an optimized contact area with the recording medium and two contact elements. Therefore, high intensity recording is possible because the intensity of near-field light irradiated onto the recording medium from the minute aperture is large and the spot diameter is small. Further, the optical recording / reproducing element and the contact element have a strength sufficient to withstand contact with a recording medium. In addition, since a light-weight optical recording / reproducing element is finely moved by a swing mechanism formed in the vicinity thereof, high-speed and high-precision tracking is possible. Furthermore, by selecting a plurality of the optical recording / reproducing elements, it is possible to perform recording and reproduction on a plurality of recording tracks on the recording medium without moving the slider. Even if one of the optical recording / reproducing elements is damaged, the other optical recording / reproducing elements can be used, so that the life of the near-field optical head can be extended. Further, since the near-field optical head of the present invention can be manufactured by a conventional semiconductor process, it can be mass-produced.
[0064]
According to a fourth aspect of the invention, in addition to the effect of the first or third aspect, the near-field optical head is formed of the optical recording element by a piezoelectric element disposed in the vicinity of the lightweight optical recording / reproducing element. / Since the reproducing element is finely moved, high-speed and high-accuracy tracking is possible.
According to the invention of claim 5, in addition to the effect of claim 1 or claim 3, since the distance between the conductive regions is very narrow, the optical recording / reproducing element can be finely moved with low power. In addition, high-speed and high-precision tracking is possible.
[0065]
According to the invention of claim 6, in addition to the effect of claim 1 or claim 3, the near-field optical head has the rocking mechanism concentrated on the slider, so that the rigidity becomes high and the resonance frequency is increased. Therefore, tracking with higher speed and higher accuracy is possible.
According to the invention according to claim 7, in addition to the effect of claim 2 or claim 3, the near-field optical head has a higher speed because the piezoelectric element directly finely moves the lightweight optical recording / reproducing element. High-precision tracking is possible.
[0066]
According to the invention of claim 8, in addition to the effect of claim 3, the near-field optical head can select the optical recording / reproducing element in contact with the recording medium.
According to the invention of claim 9, in addition to the effect of claim 3, the near-field optical head can select the optical recording / reproducing element in contact with the recording medium.
[0067]
Further, according to the invention according to claim 10, in addition to the effect of any one of claims 1 to 9, since the condenser lens system and the external light receiving element are unnecessary, the information recording / reproducing apparatus can be downsized. Easy.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an optical head according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating an optical recording / reproducing element according to Embodiment 1 of the present invention.
FIG. 3 is a cross-sectional view of an optical recording / reproducing element according to Embodiment 2 of the present invention.
FIG. 4 is a cross-sectional view of an optical recording / reproducing element according to Embodiment 3 of the present invention.
FIG. 5 is a diagram showing an apparatus configuration of an optical recording / reproducing apparatus according to Embodiment 1 of the present invention.
FIG. 6 is a diagram illustrating an optical head according to a fourth embodiment of the present invention.
FIG. 7 is a diagram illustrating an optical head according to a fifth embodiment of the present invention.
FIG. 8 is a diagram illustrating an optical head according to a sixth embodiment of the present invention.
FIG. 9 is a diagram illustrating an optical head according to a seventh embodiment of the present invention.
FIG. 10 is a diagram illustrating an optical head according to an eighth embodiment of the present invention.
FIG. 11 is a diagram showing a device configuration of a recording / reproducing device in an eighth embodiment of the present invention.
FIG. 12 is a cross-sectional view of the optical recording / reproducing element in the first embodiment of the present invention.
[Explanation of symbols]
1 Optical recording / reproducing element
2 Contact element
3 Body
4 Beam
5 Piezoelectric elements
5a Piezoelectric element
5b Piezoelectric element
6 Minute aperture
7 Reflective film
8 Optical waveguide
9 Light emitting elements
10 Conductive area
11 Rotary actuator
12 Light receiving element
13 plane
14 Track direction
15 Movable beam
16 Fixed beam
17 Selective piezoelectric element
101 optical head
102 Primary servo motor
103 Recording media
104 Recording medium drive motor
105 Condensing lens system
106 Photo detector
107 Control circuit
108 Optical recording / reproducing head moving drive circuit
109 Optical head drive circuit
110 optical head
111 suspension
121,131,141,151 Optical head

Claims (10)

A near-field optical head that performs at least one of recording and reproduction of information on a recording medium using near-field light,
A slider, two contact elements formed on the slider, a swing mechanism formed on the slider, and an optical recording / reproducing element having a minute aperture formed on the swing mechanism,
The near-field optical head, wherein the optical recording / reproducing element is in contact with the recording medium together with the two contact elements and finely moves in parallel with the recording medium surface by the swing mechanism. A near-field optical head that performs at least one of recording and reproduction of information on a recording medium using near-field light,
A slider, the two contact elements formed on said slider is constituted by a fine adjustment mechanism formed on the slider, the optical recording / reproducing device having a minute aperture formed on the fine movement mechanism,
The near-field optical head, wherein the optical recording / reproducing element is in contact with the recording medium together with the two contact elements, and is finely moved in parallel with the recording medium surface by the fine movement mechanism. A near-field optical head that performs at least one of recording and reproduction of information on a recording medium using near-field light,
A slider, two contact elements formed on the slider, at least two beams extending from the slider , a beam selection mechanism formed on each of the beams, and each of the beams A swing mechanism or a fine movement mechanism formed, and an optical recording / reproducing element having a minute aperture formed on each of the swing mechanism or the fine movement mechanism ,
One of the optical recording / reproducing elements is brought into contact with the recording medium together with the two contact elements by selectively bending the one beam toward the recording medium by the selection mechanism. A near-field optical head which is finely moved parallel to the recording medium surface by a moving mechanism and the fine moving mechanism.   The swing mechanism includes a beam extending from the slider and a piezoelectric element formed on the beam. The beam is bent by expanding and contracting the piezoelectric element, and the optical recording / reproducing element is recorded on the recording element. 4. The near-field optical head according to claim 1, wherein the near-field optical head is finely moved parallel to the medium surface.   The swing mechanism has a beam extending from the slider, a conductive region formed on a side surface of the beam, and a conductive region formed on a surface facing the conductive region, between the two conductive regions. 4. The near-field optical head according to claim 1, wherein the beam is bent by generating an electrostatic force to finely move the optical recording / reproducing element in parallel with the surface of the recording medium. .   The rocking mechanism uses a rotating mechanism and reciprocates in an arc, and the micro opening of the optical recording / reproducing element is arranged at a position eccentric with respect to the rotating shaft of the rotating mechanism. 4. The near-field optical head according to claim 1, wherein the optical recording / reproducing element is finely moved in parallel with the recording medium surface.   4. The fine movement mechanism is a piezoelectric element, and the optical recording / reproducing element is finely moved parallel to the surface of the recording medium by expanding and contracting the piezoelectric element. Near-field optical head.   4. The near-field optical head according to claim 3, wherein the selection mechanism is a piezoelectric element, and the beam is bent toward the recording medium by expanding and contracting the piezoelectric element.   The selection mechanism has a conductive region formed on a surface of the beam and a conductive region formed on a surface facing the conductive region, and generates an electrostatic force between the two conductive regions, 4. The near-field optical head according to claim 3, wherein a beam is bent toward the recording medium.   The near-field optical head according to claim 1, wherein the slider has a light receiving element.

Images