JPH09134552A - Tracking method and memory apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel tracking mechanism for recording and/or reproducing high-density information of several tens nanometers or smaller at high speed with high accuracy when the technique of a scanning probe micrometer is applied. SOLUTION: The apparatus has a recording medium 100 with a projecting/ recessed structure formed on a surface for the purpose of tracking, a leaf spring 3 with a probe 2 for writing, reading and erasing information, and a detection means for detecting a bending or torsion of the leaf spring 3. While the probe 2 is held close to or in touch with the recording medium 100, the probe and recording medium are relatively moved in a direction connecting a fixed end and a free end of the leaf spring 3. The recording medium is tracked by using a size and a direction of the torsion of the leaf spring 3 because of the projecting/recessed structure of the medium or a size of the bending and the direction of the torsion as feedback signals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tracking method for recording and / or reproducing information and a storage device using the same, and more particularly to high-speed recording and / or reproducing of a recording bit having a size of several tens nanometers or less. The present invention relates to a tracking method that is effective to perform, and can be used as a basic technology for developing ultra-high density file memory.

[0002]

2. Description of the Related Art In recent years, the progress of information society has been remarkable,
There is a demand for the development of technology capable of storing more information. Currently, in the field of file memory research, there is a demand for a technology capable of achieving high density in a size of several tens of nanometers or less. As a promising candidate, there is a scanning probe microscope technology typified by a scanning tunnel microscope. Focusing on the principle of enabling spatial resolution up to the atomic size and fine processing up to the atomic size, application to memory devices and its practical application are being energetically advanced.

[0003]

In a storage device to which the technique of the scanning probe microscope is applied, a probe is used to
Information such as nanometer size is recorded at high density on the medium surface by electrical, magnetic, thermal, optical, or mechanical methods, or a combination thereof, and the probe and the medium are brought close to each other. The high density recorded information is reproduced by detecting any physical phenomenon that occurs.

In order to record and / or reproduce high-density information having a size of several tens of nanometers or less at a high speed and with high accuracy, recording and / or recording of information along a track having a width of several tens of nanometers or less. Regeneration is required.

The present invention provides a novel tracking mechanism of a storage device for recording and / or reproducing high-density information having a size of several tens of nanometers or less at high speed and with high accuracy.

[0006]

The structure of the present invention for achieving the above object is a recording medium having a concavo-convex structure on the surface for tracking, and a leaf spring with a probe for writing, reading or erasing information. And a means for detecting the magnitude and direction of the bending and twisting of the leaf spring, and a direction connecting the fixed end and the free end of the leaf spring with the probe and the recording medium brought close to or in contact with each other. It is a memory device having means for performing relative movement and performing tracking using the magnitude and direction of twist of a leaf spring due to the concavo-convex structure or the magnitude and direction of twist as a feedback signal. In addition to the above configuration, means for performing tracking along a rotating coordinate system,
Alternatively, it is also a storage device provided with means for performing tracking along an orthogonal coordinate system.

Further, it is also a storage device in which the uneven structure for tracking the surface of the recording medium is a pit, a mound, a groove, or a combination thereof.

Further, from the plurality of signals corresponding to the magnitude and direction of twist of the leaf spring or the magnitude of deflection and direction of twist detected from a plurality of pits, mounds, grooves, or a combination thereof, the track center is detected. It is also a storage device having means for finding one signal corresponding to the amount of deviation from the above and performing tracking by using this as a feedback signal.

The operation of the present invention will be described in detail. When the probe of the leaf spring with a probe and the surface of the recording medium are brought close to each other, an atomic force acts between them. Therefore, while the probe and the recording medium are relatively moved in the direction connecting the fixed end and the free end of the leaf spring, the amount of twist of the leaf spring caused by the uneven structure for tracking formed in advance on the surface of the recording medium is large. And direction, or the magnitude of flexure and the direction of twist,
The probe is moved along the track by the feedback control.

When this means is used, the probe can be moved at high speed along a track having a width of several tens of nanometers or less, and writing, reading or erasing of recorded information of a size of several tens of nanometers or less can be performed at high speed. And it can be done with high accuracy.

[0011]

Embodiments of the present invention will be specifically described below.

Embodiment 1 FIG. 1 shows a block configuration which is an embodiment for realizing high-speed and highly accurate tracking. In this embodiment, a disc-shaped recording medium 100 made of silicon having a groove 101 for tracking on the recording medium surface as shown in FIG. 2A was used. The groove 101 was formed by a semiconductor process such that tracks of about 500 nm and grooves of 300 nm were alternately arranged. The portion sandwiched between the grooves becomes the track 102, and the recording information is written in that portion by, for example, a convex structure.

In the case of the present embodiment, the recording information is written by
This was performed by applying a voltage pulse between the probe and the recording medium to evaporate the atom at the tip of the probe to form a convex structure, but this is a method that can form a convex structure on the recording medium. For example, any one can be adopted.

In the present invention, of course, in addition to forming the concavo-convex structure as in the present embodiment, phase change writing by resistance heating of the phase change film, magnetization reversal by resistance heating of the magnetic medium, electrical using a dielectric material. It can be applied to any other method such as polarization inversion, and the reading method corresponding to each method may be adopted.
However, when reading with a probe, the diameter of the recording bit (length in the direction perpendicular to the track) must substantially match the track width so that information can be read out whenever the probe is inside the track. is there.

First, the operation of each part in the block diagram of FIG. 1 will be described. The radial direction coarse movement device 9, the radial direction fine movement device 8, the z direction coarse movement device 7, and the z direction fine movement device 6 are arranged in a cascade, and one end of the radial direction coarse movement device 9 is fixed to the device base 1000. , One end of the z-direction fine movement device 6 holds a holder 2000 for supporting a leaf spring 3 described later.

Data storage or reading, for example,
An operation of applying a signal on-a to the z-direction coarse movement control device 20 and integrating a constant voltage in response to an operation when a user of a personal computer equipped with the recording device according to the present invention attempts to record data. Gives a constant rate of increase in voltage. This is applied to the z-direction coarse movement device 7, and the probe 2 provided at one end of the leaf spring 3 is brought close to the recording medium 100 by a distance corresponding to this voltage. As a result, the probe 2 becomes the recording medium 1
When it is pressed against 00, the recording medium 100 is attached to the probe 2.
The normal force from acts. Due to this normal force, the leaf spring 3 is bent and twisted according to the surface shape of the recording medium 100.

This deformation is detected by the optical lever detection system composed of the semiconductor laser 4 and the biaxial position sensor 5, and the detection signal is sent to the deflection / twist detection circuit 11. The bending / twisting detection circuit 11 generates a bending signal and a twisting signal from the obtained output of the biaxial position sensor 5. The deflection signal is sent to the z-direction control unit 12 and the data extraction unit 13, and the twist signal is sent to the offset generation unit 14.

The z-direction control unit 12 outputs a drive signal to the z-direction fine movement device 6 so that the deflection of the leaf spring 3 becomes constant,
Feedback control. When the output signal to the z direction fine movement device 6 exceeds the predetermined value set in the level detection circuit 40, a signal is output from the level detection circuit 40 to stop the integration operation of the z direction coarse movement control device 20. It becomes an off-a signal. As a result, the voltage applied to the z direction coarse movement device 7 is held at its integral value. This level detection circuit 4
At the same time, the signal from 0 is used as a signal on-b for starting the operation of the radial coarse motion control device 30.

The radial direction coarse movement control device 30 to which the signal on-b is applied applies a voltage according to the difference between the destination track number and the current track number to the radial direction coarse movement device 9. The current track number is given as this output signal by the data extracting unit 13 by reading the track number together with the reading of the data, as described later. The radial direction fine movement device 8 has an offset generation unit 14 as described later.
Is added to perform fine follow-up control so that the probe 2 does not come off the track. After recording the data, the z-direction coarse movement control device 20 is given a reset signal from the OS of the personal computer. As a result, the voltage held by the z-direction coarse movement control device 20 is reset, and thus the probe 2 is retracted from the medium surface by the z-direction coarse movement device 7. FIG.
(B) shows various control signals to the z-direction coarse movement control device 20 and the state of voltage change corresponding thereto.

When the recording medium 100 on which the convex structure which is the recording information is formed is rotated at high speed by the rotation driving device 10, the feedback control cannot respond to the high frequency signal due to the convex structure, and the leaf spring 3 is bent. It changes corresponding to this convex structure. The data extraction unit 13 extracts a signal corresponding to the convex recording information from the change in the deflection and reads the data. That is, since it is not possible to control the leaf spring 3 so that the force acting on the probe 2 becomes constant, the leaf spring 3 repeatedly deforms in accordance with the convex structure. You can

Of course, the z-direction control unit 12 is used for the recording medium 10.
For moderate deformation such as undulation of 0, a drive signal is output to the z-direction fine movement device 6 by feedback control so that the deflection of the leaf spring 3 becomes constant.

Further, the offset generator 14 generates an offset voltage according to the transmitted twist signal and applies it to the radial direction piezoelectric element of the radial direction fine movement device 8. By arranging the direction connecting the fixed end and the free end of the leaf spring 3 in parallel to the track 102 direction, this twist signal reflects the magnitude and direction of the deviation from the track center.
It can be used as a tracking signal. The offset generator 14 outputs an offset voltage for tracking to the radial direction fine movement device 8 so that the leaf spring 3 is not twisted, that is, the probe 2 follows the track 102.

Next, the tracking mechanism will be described in detail. The movement of the probe 2 in the in-plane direction of the recording medium 100 is performed by the radial direction coarse movement device 9 and the rotation drive device 10 along the rotation coordinate system. When the probe 2 deviates from the track 102 and enters the side surface portion of the groove 101, a vertical reaction force N as shown in FIG. The leaf spring 3 is twisted by a lateral component of the normal force N parallel to the surface of the recording medium 100, so-called lateral force. Actually probe 2
The kinetic frictional force also acts on the, and twisting is also generated. This effect can be avoided by selecting a recording medium and probe material combination that has a negligible dynamic friction force for lateral force due to the uneven structure for tracking, or by applying a lubricant to the medium surface. it can.

FIG. 4 schematically shows the signal relationship when the probe 2 is on the track 102 and when the probe 2 deviates from the track 102. FIG. 4A shows the cross-sectional shape of the track 102. FIG. 4B shows the relationship between the position of the probe 2 in the radial direction r and the twist signal. This signal bends /
It is output to the offset generation unit 14 by the twist detection circuit 11. In reality, twisting is caused by the convex recording information, but it is possible to determine whether it is the convex recording information or the groove based on the bending signal. That is, in the case of convex recording information, a flexural signal corresponding thereto is generated at the same time. Therefore, when the flexural signal is sufficiently large, it can be known that the distortion is due to the convex recording information. Only in the case of the groove, the offset generation unit 14 causes the probe 2 to move as shown in FIG.
To the radial direction fine movement device 8 for outputting the offset voltage required to return the signal to the inside of the track. As a result, it is possible to write, read, or erase recording information at high speed while performing tracking control on the track 102 having a width of 500 nm.

FIG. 7 is a diagram for explaining the function of reading the recorded information and creating an offset signal for tracking. As shown in the upper part of the figure, on the surface of the recording medium 100, a track is formed between the grooves A and B as viewed from above the recording medium, and convex recording bits corresponding to the data are formed on the track. Is made. Now, the track and the probe move relative to each other, but as shown by the thick line with an arrow at the top of the figure, the probe sometimes falls off the track while passing over the convex recording bit. . In addition, a bending signal and a twisting signal are obtained in this process. As can be seen by paying attention to the time and polarity of generation of the flexure signal and the twist signal, when the flexion signal fluctuates in the positive direction and is above a certain level, data corresponding to the convex recording bit is obtained. When the flexion signal fluctuates in the negative direction and a twist signal exists, it means that the track is beginning to fall on the slope from the track to the offset signal for tracking in accordance with the polarity of the twist signal. It should be generated. Furthermore, if the probe continues to fall on the slope to the groove or to the groove for some reason, the Z-direction control unit 1
Since the control signal is issued from 2, it is still necessary to generate an offset signal when this signal lasts for a long time.

In this embodiment, the portion sandwiched between the grooves is a track. However, even when recording information is written on the bottom surface of the groove using the groove as a track, attention is paid to the steep slope existing between the track and the groove. It goes without saying that similar tracking control can be performed by performing control.

In this embodiment, the probe and the recording medium are in contact with each other, that is, the contact mode is often used in the field of atomic force microscopy. Of course, even in the non-contact mode or the tapping mode, similar tracking control can be performed by using the torsion of the leaf spring due to the lateral component of the van der Waals force from the uneven structure as the tracking signal.

Example 2 In this example, a recording medium 110 having a discontinuous tracking mark as shown in FIG. 2B was used. The tracking mark is a mound 111 having a diameter of about 50 nm formed by a semiconductor process, photolithography, or lithography using a scanning probe microscope. In this case, the width of the track 112 is 11
It will be almost the same as the diameter of 1. Such tracks 112 are formed at intervals of about 200 nm. In this embodiment, the recorded information is a mound 1 which is a tracking mark.
It is a concave structure written between 11. This writing was performed by applying a voltage pulse between the probe and the recording medium to cause the surface atoms of the medium to evaporate by electric field. That is, according to the present embodiment, the mound for tracking is formed on the flat surface of the recording medium at an appropriate period, and the recess corresponding to the signal is formed between the mounds.

Also in the case of this embodiment, in addition to forming the concavo-convex structure, phase change writing by resistance heating of the phase change film, magnetization reversal by resistance heating of the magnetic medium, electric polarization reversal using a dielectric material, etc. It can be applied to any method. However, in reading with the probe, it is good that the diameter of the recording bit is approximately equal to or slightly larger than the track width so that the information can be read out whenever the probe is in the track, but if it is too large, This can cause crosstalk between tracks.

The configuration of this embodiment will be described with reference to the block diagram shown in FIG. The operation of each block other than the error generation unit 15 is the same as that of the first embodiment. The operation at the time of starting the apparatus and the operation at the time of stopping the apparatus are the same as those in the first embodiment. The error generation unit 15 detects the peak of the twist signal sent from the flexure / twist detection circuit 11, and outputs this peak value to the offset generation unit 14. The twist signal is generated not only from the mound 111, which is a tracking mark, but also from the concave structure, which is recorded information. Whether the twist signal is from the mound or the concave structure of the recorded information can be discriminated by the bending signal according to the direction of change of the bending of the leaf spring. This point is the same as in the first embodiment. The error generation unit 15 detects the peak of only the twist signal from the bending / twist detection circuit 11 by the mound, and outputs the peak value to the offset generation unit 14.

Next, the tracking mechanism will be described in detail with reference to FIGS. As shown in FIG. 3B, when the probe 2 is displaced from the track center when passing through the mound 111, the leaf spring 3 is twisted right or left by the vertical reaction force N from the side surface of the mound 111.

FIG. 6 schematically shows a signal relationship when the probe 2 is on the track 112 and when it is deviated from the track 112. FIG. 6A shows a cross-sectional shape of the mound 111. FIG. 6B shows the relationship between the position of the probe 2 in the radial direction r and the peak value of the twist signal from the mound 111. Although the waveform of the flexure signal is omitted in FIG. 6, this is substantially the same as the shape of the mound 111. The signal from the leaf spring 3 is detected by the flexure / twist detection circuit 11, and of these outputs, the peak value detected by the error generation unit 15 from the twist signal is as shown in FIG. 6 (b). In this graph, two radial positions r correspond to one peak value, which can be distinguished by the amount of bending of the leaf spring 3. Therefore, the peak value and the offset signal in FIG. 6C can be made to correspond one-to-one with the peak value and the deflection signal. As shown in FIG. 6C, the offset generation unit 14 outputs the offset voltage necessary for returning the probe 2 to the track center to the radial direction fine movement device 8. As a result, the track 112 with a width of 50 nm is
Tracking control can be performed for.

FIG. 8 is a diagram for explaining the function of reading the recorded information and creating an offset signal for tracking. A mound for tracking is formed on the surface of the recording medium 110, and a track is formed such that a concave recording bit corresponding to recording data is formed between the mound. Now, the track and the probe move relative to each other, but as shown by the thick line with an arrow in the figure, the probe sometimes escapes from the track while passing over the mound and the concave recording bit. To do. In addition, a bending signal and a twisting signal are obtained in this process. As can be seen by paying attention to the time and polarity of generation of the flexure signal and the twist signal, when the flexion signal fluctuates in the negative direction and is above a certain level, data corresponding to the concave recording bit is obtained. When the deflection signal fluctuates in the positive direction and the torsion signal exists, it means that the signal does not move correctly on the center of the mound, so the offset signal for tracking corresponds to the polarity of the torsion signal. Should be generated. Therefore, the deflection signal,
For both the twist signal, the peak value may be detected and used.

Writing, reading, or erasing of recorded information can be performed separately from tracking control by a method used in the following ordinary optical recording and the like. By forming a fixed number of mounds, which are tracking marks, around the track, the tracking marks appear at a constant cycle when the recording medium is rotated. Therefore, if the recording information is written, read, or erased in the data area between the tracking marks, the track signal and the data signal can be temporally separated.

Although the mound is the tracking mark in this embodiment, it is needless to say that similar tracking control can be performed using the convex structure as the recording information even when the pit is used as the tracking mark. In this embodiment, the probe and the recording medium are in contact with each other, that is, in the contact mode which is often used in the field of atomic force microscopy. Of course, in the non-contact mode and the tapping mode, the van der Waals from the uneven structure is also used. It goes without saying that similar tracking control can be performed by using the twisting of the leaf spring due to the lateral component of the force as the tracking signal.

Example 3 In this example, a recording medium 120 having lands 121 and tracks 122 as shown in FIG. 2C was used. As is clear from comparison with FIG. 2A, since the land and the track are formed by repeating smooth continuous waves, a recording device with higher density can be configured. With this configuration, as shown in FIG. 3C, the portion between the lands 121, which is a more stable position, is used as the track 122. In this example, although the relationship is opposite to that of FIG. 3B, when the probe 2 tries to come off the track, the normal force N
Is generated, it can be used for tracking.

FIG. 12 schematically shows the signal relationship between the case where the probe 2 is on the track 122 and the case where the probe 2 deviates from the track 122, similarly to FIG. 6 in the second embodiment. FIG. 12A shows the cross-sectional shape of the track 122. (B) is the position of the probe 2 in the radial direction r and the track 12
2 shows the relationship with the twist signal from 2. By performing servo control so that the twist signal becomes 0, the track 122
Tracking control for.

FIG. 13 is a diagram for explaining the operation of reading recorded information. As shown in the cross-sectional shape on the upper left side of the figure, lands for tracking are formed on the surface of the recording medium 120, and tracks are formed with concave recording bits corresponding to the recording data formed between the lands. Composed.
Now, the track and the probe move relative to each other, but the probe passes over the track and the concave recording bit as shown by a thick line with an arrow in the figure. In this example, since the probe is arranged at the most stable position, it does not largely deviate from the track, but as shown in FIG. 12, a twist signal is generated according to the deviation from the center position. Further, a change in the flexure signal can be obtained corresponding to the concave recording bit. This deflection signal is used as data. Here, the torsion signal that appears corresponding to pit has a very high frequency compared to the torsion signal in Fig. 12 (b), so the dynamic direction control unit 18 cannot follow it and is eventually ignored. Therefore, unnecessary tracking operation will not be performed.

FIG. 10 shows an embodiment in which the piezoresistive strain gauge 17 is used instead of the optical lever as the recording bit signal detector. In this embodiment, the leaf spring 3 has a piezoresistive strain gauge 17
Is attached, and the output is the deflection / twist detection circuit 11
Will be introduced. Among the outputs of the flexure / twist detection circuit 11, a twist signal is introduced into the radial direction control unit 18, and a signal for controlling the twist signal to always be 0 (track center) is output to the radial direction fine movement device 8. To do. Of the outputs of the bending / twisting detection circuit 11, the bending signal is the z-direction control unit 12
And the data extraction unit 13 respectively. The z-direction control unit 12 generates a signal for controlling the deflection signal to a certain constant value so that a constant repulsive force acts between the probe 2 and the recording medium 120, which is the z-direction fine movement device 6
Is added to In the data extraction unit 13, the z-direction control unit 1
The deflection signal due to the concave recording bit on the higher frequency side of the frequency band of the signal to be processed 2 is extracted.

Except for the above-mentioned parts of the present embodiment, the structure is essentially the same as that shown in FIG. 1 or FIG. Also, when the recording information is a convex recording bit, it can be dealt with by changing the above-described portion accordingly, but the description thereof will be omitted.

Next, a specific example of the bending / twisting detection circuit 11 will be described with reference to FIG. The leaf spring 3 is divided into two parts except the tip of the probe 2, and piezoresistive strain gauges 171 and 172 are attached to each part. These resistors R + ΔR ₁ and R + ΔR ₂ are inserted in one side of the Wheatstone bridges B ₁ and B ₂ . The probe 2 follows the shape of the surface of the recording medium 120,
Since these resistance values change in accordance with the deformation of the leaf spring 3, the outputs a and b of the differential amplifiers G ₁ and G ₂ of the Wheatstone bridges B ₁ and B ₂ change correspondingly. . The outputs a and b of the differential amplifiers G ₁ and G ₂ can be calculated by a calculation circuit as a + b to obtain a deflection signal and a−b as a twist signal.

Embodiment 4 An embodiment of a multi-probe using two probes will be described with reference to FIG. In this embodiment, a recording medium 110 having a mound 111 which is a discontinuous tracking mark as shown in FIG. 2B on a track 112 is used. The diameter of the mound 111 is about 50 nm. Such tracks 112 are formed at intervals of about 800 μm. In this embodiment, the recording information has a concave structure which is written in the data area between the tracks. This writing was performed by applying a voltage pulse between the probe and the recording medium to cause the surface atoms of the medium to evaporate by electric field.

In this embodiment, the probe A and the leaf spring A are used exclusively for tracking, and the probe B and the leaf spring B are used exclusively for recording / reproduction. The probe A and the leaf spring A detect the mound 111 as in the second embodiment, and the bending and twisting of the leaf spring A are used to perform tracking on the track 112.
The probe B and the leaf spring B are fixed to the support 16 together with the probe A and the leaf spring A, and the distance between the probe A and the probe B is about 4
It is 00 μm. Therefore, by the probe B and the leaf spring B, the data area 113 is independent of the probe A and the leaf spring A.
It is possible to record information in and reproduce the information. In the case of this embodiment, the leaf springs A and B need to be sufficiently bent in order to keep the probe A and the probe B in contact with the surface of the recording medium during the rotation of the recording medium.
Further, by using a plurality of such two sets of probes, it is possible to perform tracking and recording / reproducing independently.

In the present embodiment, the diameter of the recording bit is set to the diameter of the mound 111 on the track 112 in order to read the information by the probe B without fail if the probe B is in the data area 113. It is good to make it about 3 times. That is, recording is performed when the probe A for tracking is at the limit position on both sides of the mound 111,
This is because in order to be able to read out, it is necessary to record and read out with the probe B at this position.

Other Embodiments Embodiments in the case of multi-valued recording by using convex and concave structures for recording information or using this together with another information recording method will be described. Simply by using the convex and concave structures as the recording information and using the same tracking method as in the second embodiment, ternary recording can be easily realized. Writing, reading, or erasing of recorded information can be performed separately from tracking control by a method used in the following ordinary optical recording or the like. By forming a certain number of mounds, which are tracking marks, around a track, when the recording medium is rotated, the tracking marks appear at a constant cycle. Therefore, if the recording information is written, read, or erased in the data area between the tracking marks, the track signal and the data signal can be temporally separated. In this case, independently of tracking control,
Recording information can be written, read, or erased in the data area. A voltage pulse is applied between the probe and the recording medium to cause the surface atoms of the medium to be field evaporated.
Alternatively, the convex and concave structures are formed by field-evaporating the probe atoms and supplying the atoms to the surface of the medium. By associating the convex and concave structures with recorded information, ternary recording can be performed.

In addition to the convex and concave structures, electric and magnetic forces from the surface of the recording medium are also used as recording information, and if this is multivalued data, multivalued recording of four or more values can be realized. .

In each of the above-described embodiments, the twisting or bending of the leaf spring which becomes the tracking signal is caused by the force from the uneven structure on the surface of the recording medium. Of course, this force is applied electrically or magnetically from the surface of the recording medium. The same tracking control can be performed even when the force is applied or a combination thereof. In this case, an electric polarization medium and a conductive probe using a ferroelectric substance or a combination of a magnetic medium and a magnetic probe is used. A polarization pattern for tracking is previously formed on the medium. By utilizing the twist of the leaf spring due to the lateral component of the electric or magnetic force from this polarization pattern for the tracking signal, the same tracking control as in the first and second embodiments can be performed.

Regarding the case where the recorded information has a concave structure, in the above-mentioned embodiment, the electric field evaporation is used.
This can be done by mechanical pressing. For example, in the embodiment of FIG. 10, as shown in FIG. 10B, the leaf spring 3 to which the piezoresistive strain gauge 17 is attached is attached to the holder 2000 via the bimorph type piezoelectric element 3000. Then, when recording the information of the concave structure, a predetermined voltage is applied to the bimorph type piezoelectric element 3000 to control the probe 2 to be strongly pressed against the surface of the recording medium, and when reading the information. The bimorph type piezoelectric element 3000 may be treated as a structure in which the leaf spring 3 to which the piezoresistive strain gauge 17 is attached and the holding body 2000 are connected as a simple structure without applying a voltage.

Further, the relative movement between the recording medium and the probe is not limited to the rotation as in the first and second embodiments, but may be X.
It goes without saying that the present invention can be applied even when the linear movement is performed using the −Y coordinate system. FIG. 14 shows a block configuration when a stage 4000 driven in the Y direction by a piezoelectric element is adopted instead of the rotary spindle 10 of the embodiment shown in FIG. 10 to realize this. At this time, the radial direction fine movement device 8, the radial direction coarse movement device 9, and the radial direction coarse movement control device 30 are respectively the X direction fine movement device 8, the X direction coarse movement device 9, and the X direction coarse movement control device 30. And the movement direction control unit 18 may be replaced with the x direction control unit 18. Since the operation in this configuration may be performed by driving in the Y direction instead of rotation and controlling in the radial direction by controlling in the X direction, a specific description will be omitted.

Further, in all of the above embodiments, the probe 2, the leaf spring 3, the semiconductor laser 4, the biaxial position sensor 5, the piezoresistive strain gauge 17, the holder 2000, and the bimorph type piezoelectric element 300.
It is also possible to mount 0 or a part or all of the fine movement / coarse movement devices 6, 7, 8 and 9 on a slider and control the probe 2 in the z direction by the slider.

[0051]

As described above, according to the present invention, it is possible to move the probe at high speed along a track having a width of tens of nanometers or less. Writing, reading, and erasing can be performed at high speed and with high accuracy.

[Brief description of the drawings]

1A and 1B are diagrams showing waveforms for explaining the operation of a z-direction coarse motion control device among the block configurations and the components thereof according to a first embodiment of the present invention.

2A, 2B, and 2C are diagrams showing examples of recording media to which the present invention is applicable.

3 (a), (b) and (c) are diagrams showing the drag force acting on the tip of the probe and the twisting of the leaf spring when passing through the track mark structure of the recording medium of FIG.

4A, 4B, and 4C are diagrams showing a track cross-sectional shape, a twist signal, and an offset voltage according to the first embodiment.

FIG. 5 is a diagram showing a block configuration of a second embodiment of the present invention.

6 (a), (b) and (c) are diagrams showing a mound cross-sectional shape, a twist signal (peak value), and an offset voltage according to the second embodiment.

FIG. 7 is a diagram for explaining the function of reading offset information and creating an offset signal for tracking in the first embodiment.

FIG. 8 is a diagram for explaining the operation of reading offset information and creating an offset signal for tracking in the second embodiment.

FIG. 9 is a diagram illustrating an embodiment having a multi-probe configuration.

10A and 10B are diagrams showing a block configuration of a third embodiment of the present invention and a partially modified configuration thereof.

FIG. 11 is a diagram showing details of an example of a configuration of a bending / twisting detection circuit according to a third embodiment of the present invention.

FIG. 12 is a diagram for explaining the function of reading offset information and creating an offset signal for tracking in the third embodiment.

FIG. 13 is a diagram for explaining the operation of reading recorded information according to the third embodiment.

FIG. 14 is a diagram showing a block configuration of another embodiment of the present invention.

[Explanation of symbols]

100, 110, 120 ... Recording medium, 101 ... Groove, 111 ... Mound, 102, 112, 122 ... Track, 121 ... Land, 113 ... Data area, 2 ... Probe, 3 ... Leaf spring, 4 ... Semiconductor laser, 5 ... 2-axis position sensor, 6 ... z-direction fine movement device, 7 ... z-direction coarse movement device,
8 ... Radial direction fine movement device, 9 ... Radial direction coarse movement device, 10 ...
Rotation drive device, 11 ... Deflection / twist detection circuit, 12 ... z
Direction control unit, 13 ... Data extraction unit, 14 ... Offset generation unit, 15 ... Error generation unit, 16 ... Support base, 17 ... Piezoresistive strain gauge, 18 ... Radial direction control unit, 20 ... Z direction coarse movement control device , 30 ... Radial direction coarse movement control device, 40 ... Level detection circuit, 171, 172 ... Piezoresistive strain gauge,
1000 ... Device base, 2000 ... Holder, 3000 ... Bimorph type piezoelectric element, 4000 ... Y direction drive stage.

Claims (19)

[Claims] 1. A recording medium having on track a first information for tracking and a second information as a recording,
A method for tracking a recording apparatus, comprising: a means for holding a probe for moving a signal relative to the recording medium to derive a signal corresponding to the first and second information. A tracking method, characterized in that a signal relating to the magnitude and direction of the flexure or twist acting on the holding means corresponding to the first and second information is fed back to the holding means for tracking. 2. The first information for tracking is calculated from the signal relating to the magnitude and direction of the twist acting on the holding means in correspondence with the first and second information acting on the probe. The tracking method according to claim 1, wherein the second information as a record is respectively identified from the signals relating to the size and the orientation. 3. A recording medium having on track a first information for tracking and a second information as a recording,
A means for holding a probe for moving relative to the recording medium to derive a signal corresponding to the first and second information;
A storage device comprising: means for feeding back to the holding means a signal relating to the magnitude and direction of the bending or twist acting on the holding means corresponding to the first and second information acting on the probe. 4. The first information for tracking is calculated from the signal concerning the magnitude and direction of the twist acting on the holding means in correspondence with the first and second information acting on the probe. The storage device according to claim 3, wherein the second information as a record is respectively identified from the signals regarding the size and the orientation. 5. A recording medium having a first information area for tracking and a second information area for recording on a track, and the recording medium moving relative to the respective information areas of the recording medium. 1. A tracking method for a recording apparatus, comprising: a means for holding an independent probe for deriving a signal corresponding to first and second information, wherein the first and second methods act on the independent probe. A tracking method, characterized in that a signal relating to the magnitude and direction of the flexure or twist acting on the holding means corresponding to information is fed back to the holding means for tracking. 6. A recording medium having a first information area for tracking and a second information area for recording on a track, and the recording medium moving relative to the respective information areas of the recording medium. A recording device comprising: means for holding an independent probe for deriving a signal corresponding to first and second information, wherein the first and second devices act on the independent probe.
A storage device which feeds back a signal relating to the magnitude and direction of the flexure or twist acting on the holding means in correspondence with the information of (1) to the holding means for tracking. 7. The storage device according to claim 6, wherein the first information area and the second information area are separate routes for movement of the respective probes. 8. A recording medium having a concavo-convex structure on the surface for tracking, a leaf spring having a probe for writing, reading or erasing information at its free end, and means for detecting bending and twisting of the leaf spring. A control means for controlling the bending and twisting of the leaf spring that acts on the fixed end of the leaf spring, and that the probe and the recording track of the recording medium in the state where the probe approaches or contacts the recording medium. Is relatively moved, and a signal relating to the magnitude and direction of bending or twisting of the leaf spring due to the uneven structure related to the recording track is fed back to the control means for tracking. 9. The storage device according to claim 8, wherein instead of the concavo-convex structure, an electric force from the surface of the recording medium, a magnetic force, or a force acting on the probe by a combination thereof is used. . 10. The storage device according to claim 8, wherein, in addition to the concavo-convex structure, a force acting on the probe by an electric force from the recording medium surface, a magnetic force, or a combination thereof is used. . 11. The storage device according to claim 6, further comprising means for tracking relative movement between the probe and the recording track of the recording medium along a rotational coordinate system. 12. The storage device according to claim 6, further comprising means for tracking relative movement between the probe and the recording track of the recording medium along an orthogonal coordinate system. 13. The storage device according to claim 6, wherein the uneven structure for tracking the surface of the recording medium is a pit, a mound, a groove, or a combination thereof. 14. A timing of a tracking signal is judged from a deflection signal of a leaf spring detected from a plurality of pits, mounds, grooves, or a combination thereof, and the magnitude and direction of the twist of the leaf spring or the deflection of the deflection is determined. 2. The tracking method according to claim 1, wherein one signal corresponding to the amount of deviation from the track center is found from a plurality of signals corresponding to the magnitude and the twisting direction, and this signal is used as a tracking feedback signal. . 15. A recording medium having a concavo-convex structure on the surface for tracking, a leaf spring with a probe for writing / reading and erasing information, and means for detecting bending and twisting of the leaf spring, and While the probe and the recording medium are brought close to or in contact with each other, they are relatively moved in the direction connecting the fixed end and the free end of the leaf spring, and the magnitude and direction of the twist of the leaf spring due to the concavo-convex structure are used as feedback signals for tracking. A storage device having means. 16. The relative movement between the probe and the recording medium is in the direction connecting the fixed end and the free end of the leaf spring.
The storage device according to any one of 1. 17. The storage device according to claim 6, wherein the relative movement between the probe and the recording medium is a rotating coordinate system. 18. The storage device according to claim 6, wherein the relative movement between the probe and the recording medium is an orthogonal coordinate system. 19. A track center based on a plurality of signals corresponding to the magnitude and direction of twist of a leaf spring or the magnitude of deflection and direction of twist detected from a plurality of pits, mounds, grooves, or a combination thereof. The storage device according to any one of claims 6 to 10, wherein one signal corresponding to the amount of deviation from is found and used as a feedback signal.