JPH11154363A - Information recording medium and information detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a read-only information recording medium of a high recording density, an information recording medium which allows recording and reproducing at the high recording density and an information detector which reads out such information. SOLUTION: A sensor 2 consisting of a resistor is mounted on a slider 3 floating on a disk 2 and produces output in correspondence to the projecting parts 4 formed on the disk 1. The sensor 2 is so arranged as to scan the top of the projecting parts 4 of the disk 1 slightly apart therefrom. If the disk 1 is assumed to rotate in the direction shown by an arrow R, the sensor 2 increases the release of heat energy at the front ends (a) of the projecting parts 4. The lowering of the temp. and the decreasing of the resistance value as well as the degrading of the output are resulted. The temp. remains constant while the heat applied on the resistor and heat radiation maintain equilibrium. The heat radiation decreases at the rear end (b) of the projecting parts 4. The elevating of the temp., the increasing of the resistance value as well as the increasing of the sensor output are then resulted. The projecting parts 4 formed in correspondence to the information on the disk 1 are detected by this mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording medium and an information detecting device which are provided with irregularities corresponding to information on the upper surface of a substrate and which detect irregularities using a detecting member whose resistance value changes due to a change in thermal energy.

[0002]

2. Description of the Related Art Today, magnetic recording technology and magneto-optical recording technology have been remarkably widespread, which is because their recording media are inexpensive. For example, in a recent hard disk drive using magnetic recording technology, 50,000
It is possible to record information at a cost of byte / yen. This means that if one byte is required to record one character of the alphabet, it costs only 1 yen to record 50,000 characters in this recording medium. Also, in the case of a magneto-optical disk device using the magneto-optical recording technology, although it is more expensive than magnetic recording, 3300
It has become possible to record information at a low cost of bytes / yen.

Under such circumstances, research and development have been actively conducted for the purpose of further improving the recording density and reducing the cost. For example, in order to greatly increase the areal recording density in magnetic recording, it is necessary to increase the recording density in the track width direction and the bit length direction. 10Gbits / i
At a recording density equivalent to n ² , the track density is 25 kTPI
(Tracks Per Inch), linear recording density is 4
00kFCI (Flux Changes Per I
nch) (two)
Material of the 93rd meeting of the Japan Society of Applied Magnetics 93-7).

[0004] 10 Gbits / i in this magnetic recording
It is said that the following three element technologies are required to realize n ² . (1). Technology relating to magnetic head and magnetic recording medium capable of recording and reproducing with a track width of about 1 μm (2). HDI (Hea) that can secure an extremely low flying height stably
d / Disk Interface) (3). This is a technology related to an actuator that can be controlled in a high band corresponding to a track width of about 1 μm. At the R & D level, 5 Gbits / in ² recording has been realized (Mutoh et al., Intermag).
Conference 96 FC-07). As a result, it can be said that the above-mentioned elemental technology is basically in a substantially solved state.

[0005] High bandwidth servo technology for actuators has been actively studied for a long time, and 10 Gbits
At 25 kTPI corresponding to / in ² , the servo band has a spindle rotation speed of 5400 rpm (rotation speed).
r minute) is 3 kHz or more, and 7200 r
It is said that 4 kHz or more is required in pm. For this reason, a high-precision actuator corresponding to 3 to 4 kHz has been developed. However, the writing method of the positioning signal of the actuator is still a conventional servo track writer (S
This is actually performed using the method of TW (Servo Track Writer).

In the STW, a magnetic head used for recording and reproducing data is used as a magnetic head for writing a positioning signal. The position control of the magnetic head is performed by driving a head carriage in the magnetic disk drive, on which the magnetic head is mounted, via an induction pin by an actuator positioned accurately outside the magnetic disk drive. However, in this method, only the guide pin is accurately positioned, and then the vibration of the carriage and the magnetic head, the NRRO of the spindle,
(Bure: Non Repeatable Run Ou
t) is written on the medium as a steady swell of the position signal when writing the position signal. For example, the NRRO of a ball bearing supporting a spindle is 0.3 μm at the maximum.
To this extent, writing a position signal using this spindle may result in a narrow pitch between adjacent tracks, or in the worst case erase a track, even if the guide pins are correctly positioned. Will occur.

Generally, a positioning signal is written by dividing one track into several times. Originally, recording with a magnetic head is unavoidable of recording bleeding (side writing), which is substantially constant regardless of the recording track width.
Therefore, as the track width becomes smaller, the ratio of the side lighting width per track width becomes larger. For example, 1
At a track pitch of about 1 μm that realizes 0 Gbits / in ² , the sidewriting width cannot be ignored. When a position signal is written with a magnetic head having such side writing, an erase band is generated at a position where the position signal is written. Since this erase band is generated every time a positioning signal is written, if one track is divided into several times and written, several erase bands will be generated on this track, and the S / N of the position signal will be degraded. Had become.

In view of the above, in order to improve the areal recording density in magnetic recording, in addition to the above-described three elemental technologies, a position signal writing technique is also an important issue.

[0009]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a read-only information recording medium having a high recording density, an information recording medium capable of recording and reproducing at a high recording density, and an information detecting apparatus for reading these. With the goal.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and according to the first aspect of the present invention, a convex portion or a concave portion corresponding to information is formed on a substrate. An information recording medium, comprising: a convex portion of the information recording medium;
Alternatively, an information recording medium for reading recorded information by exchanging thermal energy between the concave portion and the detector is configured.

According to the eighth aspect of the present invention, there is provided an information recording medium in which a convex portion or a concave portion corresponding to position information is formed on a substrate and further has a recording / reproducing area. An information recording medium for reading out position information by exchanging thermal energy between a convex portion or a concave portion of the recording medium and the detector is constituted.

In order to read the information recorded on the information recording medium according to the first and eighth aspects, the detector has an information detecting device using a detecting member whose resistance value changes by exchanging thermal energy. I do.

A slider provided with a detecting member is provided on an information recording medium having a convex portion corresponding to the information according to the first and eighth aspects, and the detecting member comes into contact with the convex portion of the information recording medium. An information detection device is configured in which heat energy is exchanged to change the resistance value of the detection member, and information is detected based on the changed resistance value.

[0014] An information recording medium having a convex portion or a concave portion corresponding to the information described in claim 1 and claim 8,
A slider provided with a detecting member to which thermal energy is continuously supplied is provided, and the detecting member is moved slightly over the convex portion or the concave portion of the information recording medium, thereby exchanging heat energy to perform the detecting member. The resistance value changes,
An information detection device configured to detect information based on the changed resistance value is configured. Also, the flying height variation of the slider flying above the information recording medium is assumed to be within 5% of the flying height.

The information recording medium according to the first and eighth aspects is in the form of a disk or a card.

According to the present invention, an MR element or a GMR element is used as a detecting member for detecting information from the information recording medium.

In the information recording medium according to the present invention, the recordable / reproducible area is a magnetic recording layer formed by magnetic means.
Alternatively, the above problem is solved by using an optical recording layer formed by optical means or a magneto-optical recording layer formed by magneto-optical means.

According to the above-described information recording medium and information detecting device, there is no recording bleed or erase band by magnetic recording for a positioning signal in the conventional magnetic recording technology, so that the S / N is good and the density can be increased. Becomes

In the magnetic disk drive, the positioning signal of the information recording medium has been sent by the STW. This causes a steady swell of the position signal, uneven pitch between adjacent tracks, and erasure of tracks. To prevent

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIGS. Here, FIG. 1 is a diagram showing a relationship between a projection provided on an information recording medium and an output from a sensor according to the present invention, and FIG. 2 is a schematic diagram showing a configuration of a signal detection circuit. FIG. 3 is a diagram showing the arrangement of data zones and servo zones on a disc-shaped information recording medium according to the present invention, FIG. 4 is a schematic diagram showing the information pattern, and FIG. 5 is a main part of the information pattern. It is an enlarged view. FIG. 6 is a schematic diagram showing a reproduction system of a disk-shaped read-only information recording medium according to the first embodiment of the present invention. FIG. 7 is a diagram for explaining the signal detection of the first embodiment according to the first embodiment, and FIG. 8 is a measurement diagram showing the tracking accuracy. FIG. 9 is a diagram for explaining signal detection in Example 2 according to the first embodiment, and FIG. 10 is a measurement diagram showing the tracking accuracy. FIG. 11 shows the first
FIG. 12 is a diagram for explaining signal detection of Example 3 according to the embodiment of the present invention, and FIG. 12 is a measurement diagram showing the tracking accuracy. FIG. 13 shows a second embodiment of the present invention.
FIG. 3 is a schematic diagram showing a reproduction system of a disc-shaped recordable information recording medium according to the embodiment.

The present invention relates to a high-density and inexpensive read-only information recording medium, a high-density and inexpensive information recording medium capable of recording and reproducing with a high S / N ratio, and an information detecting device for these. The information recording medium is formed by providing a projection or a depression corresponding to information on a substrate, and uses a resistor whose resistance value changes with temperature as a detector. The resistance value of the resistor changes due to the heat generated in the resistor or the heat taken away depending on the positional relationship between the resistor and the convex portion or the concave portion, and the information is read based on the change.

As shown in FIG. 1, a sensor 2 made of a resistor is mounted on a slider 3 that floats on an information recording medium (hereinafter, referred to as a “disk”) 1, and a convex portion formed on the disk 1 is provided. 4 is output. In the figure, disk 1
The sensor 2 is slightly spaced apart from the convex portion 4 of the disk 1 and the disk 1 is rotating in the direction indicated by the arrow R. When the disk 1 rotates and the sensor 2 reaches the tip a of the convex portion 4, the dissipation of heat energy from the resistor in the direction of the convex portion 4 increases, the temperature of the resistor drops, and the resistance value decreases. At the same time, the output of the sensor 2 decreases. The temperature is constant while the heat supplied to the resistor and the heat radiation are balanced, and when the sensor 2 moves away from the protrusion 4 at the rear end b of the protrusion 4, the temperature of the resistor increases again and the resistance value increases. Therefore, the output of the sensor 2 also increases. In this way, it is possible to detect the protrusions 4 provided on the disk 1 in accordance with the information.

In the present invention, a concave portion may be formed in place of the above-mentioned convex portion, and a signal may be obtained by scanning the upper portion of the concave portion with a slight distance therebetween. The scanning may be performed, and a signal may be obtained based on a change in frictional heat at that time. These modes will be described in detail later.

A circuit for detecting a signal from the sensor 2 is, for example, as shown in FIG. 2. A constant current power supply 5 is connected to both ends of the sensor 2 so that a constant current is always supplied to the sensor 2. A voltage corresponding to the resistance value is generated at both ends. By detecting this voltage, a change in the resistance value of the sensor 2 can be detected as a change in the voltage.
The information recorded by the unevenness provided on the disk 1 can be read. Further, the resistor constituting the sensor 2 is heated by the constant current power supply 5, and a predetermined temperature is maintained as a reference in relation to heat radiation, and the resistance of the resistor is set to a reference value.

Further, when a signal is detected by bringing a resistor into contact with a convex portion, the heat due to friction is proportional to the contact area and the relative speed as shown in equation (1). Generally, the resistance value of the resistor also increases in proportion to the temperature rise of the resistor. Generated frictional heat (Q) = vWμ (1) where, v: relative speed between the sensor and the convex portion W: contact area between the sensor and the convex portion μ: coefficient of friction between the sensor and the convex portion

As described above, the protrusion 4
In addition to the method of generating frictional heat by direct contact with the sensor and providing a temperature change, as described above, the sensor 2 simply radiates heat from the resistor just by passing the sensor 2 above the concave / convex portion. Can be detected by the method of giving

The reason is that the current is always supplied to the sensor 2 by the constant current power supply 5, so that the resistor generates heat and is usually kept at a temperature balanced with the heat radiation.
This heat is radiated not only to the slider 3 on which the sensor 2 is mounted, but also to the disk 1 which is separated from the sensor 2 only by about several tens of nm. For example, when a concave portion is formed as a signal, when the sensor 2 passes through the concave portion formed on the disk 1, the distance between the sensor 2 and the disk 1 is large, so that heat radiation from the sensor 2 becomes difficult. Therefore, the temperature rises, and accordingly, the resistance value of the sensor 2 increases, and the output increases. Conversely, when the disk 1 is levitating and running on a flat portion, the distance between the sensor 2 and the disk 1 is reduced, so that heat is radiated well, so that the resistance value of the sensor 2 is reduced and the output is reduced. In this way, the recess is detected.

As described above, the signal can be detected as a voltage change corresponding to the unevenness by applying or removing heat to or from the sensor 2 by the uneven portion formed on the disk 1. By forming the concave and convex portions on the information recording medium in response, it is possible to form a read-only information recording medium, or to form only a position signal as information, and to perform recording and reproduction with an information area capable of recording and reproduction. It is possible to configure an information recording medium. still,
For an information recording medium capable of recording and reproduction, recording and reproduction means integrated with the sensor 2 is required.

FIG. 3 shows the information recording pattern of the disk 1 thus prepared. The disk 1 has, for example, 224 servo zones 20 and data zones 21 in one round, and its pattern is traced when the sensor 2 moves from the inner circumference to the outer circumference by being rotated by the rotating arm. It is arranged to correspond. In an apparatus configured to move the sensor 2 by a carrier that moves linearly along the radial direction of the disk 1, the servo zone 20 and the data zone 21 are formed radially. FIG. 4 shows an example of the recording data pattern of the servo zone 20 and the data zone 21, and FIG. 5 shows an enlarged view of the portion A in FIG. Addresses and track position signals are provided in the servo zone 20 shown in FIGS.

First Embodiment The first embodiment relates to a disk-shaped read-only information recording medium, and FIG. 6 shows an example of the configuration of a reproducing system. The disk 1 is rotated by a spindle motor 6 in a direction indicated by an arrow R at a predetermined rotation speed. The sensor 2 is mounted on a slider 3. The slider 3 is mounted on the tip of an arm 7, and the other end of the arm 7 is mounted on an arm driving device 8 and is rotatable. After the output from the sensor 2 is detected by the signal detection circuit 11, the signal is separated into various signals by the signal processing circuit 12 and subjected to signal processing.
The record information is output. A control signal of the apparatus is input to a control circuit 13 and input to a spindle motor 6, an arm driving device 8 and the like via a driver 14, and controls the rotation speed, tracking, and the like.

The embodiment of the disk 1 according to the first embodiment and an example of signal detection by the sensor 2 corresponding thereto will be described below.

Embodiment 1 Embodiment 1 is a disk 1a provided with a convex portion 4 corresponding to information on a substrate as shown in FIG. 7, and a sensor 2 mounted on a slider 3 is brought into contact with the convex portion 4. This is a read-only information recording medium that reads information recorded in advance by scanning the information.

The protrusion 4 is formed by using a stamper so as to have a height of 80 nm when the disk 1a is formed of resin. Thereafter, a carbon layer having a self-lubricating action was formed as a protective layer on the substrate by a sputtering method, and a lubricant was applied. In addition, the method of forming the protrusion 4 is not limited to the above-described method, and may be formed by etching using a glass disk, for example. The protective layer is not limited to the carbon layer and may be a silicon-based material.

Further, tantalum, for example, can be used as a material of the sensor 2, but the material is not limited to this, and a resistor such as permalloy or copper may be used. However, in order to increase the detection sensitivity, a material having a large resistance change due to heat is preferable.
The width of the sensor 2 is, for example, 2.5 μm and its resistance value is 30Ω.
It is formed so that The constant current flowing through the sensor 2 is 14 mA. The slider 3 on which the sensor 2 is mounted is a negative pressure slider type, and the flying height of the slider 3 is 50 nm.
And the sensor 2 is brought into contact with the above-mentioned convex portion 4 formed on the disk 1a. The flying height of 50 nm prevents the slider 3 from fluctuating when the sensor 2 comes into contact with the disk 1a, thereby preventing the slider 3 from losing its balance and falling off. This is in order to obtain sufficient contact with.

The height of the projection 4, the width of the sensor 2, the resistance of the resistor, the constant current flowing through the sensor 2, the flying height of the slider 3, and the like are not limited to the above-mentioned values, and the projection can be satisfactorily improved. 4 may be set to another value that can be detected. The width of the sensor 2 was 2.5 μm, but as described in the conventional example, the width of the sensor 2 was 1 μm.
In order to realize 0 Gbits / in ² , it is natural that the sensor should be manufactured with a sensor width of 1 μm or less corresponding to a track width of about 1 μm. These are the same in Examples 2 to 6 described later.

FIG. 7 shows waveforms obtained by performing an information reading experiment in the configuration of the disk 1a and the sensor 2 described above. From FIG. 7, it can be seen that an output is obtained from the sensor 2 corresponding to the projection 4 provided on the surface of the disk 1a.
In the figure, the sensor output sharply rises at the tip a of the projection 4, which is probably because the sensor 2 strongly hits the tip a of the projection 4 and the frictional heat sharply increased. The quality of the output signal was the same as that of the information signal in the conventional magnetic recording system.

FIG. 8 shows the result of measurement of the deviation of the sensor 2 from the track while the disk 1a makes one revolution under the tracking control. From FIG. 8, it can be confirmed that the error of the sensor 2 from the track is 5% or less of the track width, and is within about 5% of the sensor width formed narrower than the track width. This is equivalent to the accuracy of tracking control performed using a conventional positioning signal. The time on the horizontal axis is standardized and corresponds to one round of the disk with a numerical value of 100.

Embodiment 2 Embodiment 2 is a disk 1b provided with a concave portion 9 corresponding to information on a substrate as shown in FIG. 9. Heat energy is applied slightly apart from the concave portion 9 above. This is a read-only information recording medium that reads information recorded in advance by scanning a sensor 2 made of a resistor.

The concave portion 9 is formed using a stamper so as to have a depth of 200 nm when the disk 1b is formed of resin. Thereafter, a carbon layer having a self-lubricating action was formed as a protective layer on the substrate by a sputtering method, and a lubricant was applied. Note that the method of forming the concave portion 9 is not limited to the above-described method, and may be formed by, for example, etching using a glass disk. The protective layer is not limited to the carbon layer and may be a silicon-based material.

Further, for example, tantalum can be used as the material of the sensor 2, but the material is not limited to this, and a resistor such as permalloy or copper may be used. However, in order to increase the detection sensitivity, a material having a large resistance change due to heat is preferable.
The width of the sensor 2 is, for example, 2.5 μm and its resistance value is 30Ω.
It is formed so that The constant current flowing through the sensor 2 is 14 mA. The slider 3 on which the sensor 2 is mounted is a negative pressure slider type, and the flying height of the slider 3 is 50 nm.
And The flying height of 50 nm prevents the slider 3 from fluctuating when the sensor 2 passes over the recess 9, thereby preventing the slider 3 from losing its balance and falling off.
This is because heat is sufficiently transferred from the sensor 2 to the concave portion 9.

FIG. 9 shows waveforms obtained by conducting an information reading experiment in the configuration of the disk 1b and the sensor 2 described above. In the figure, since the heat radiation from the resistor decreases in the concave portion 9, the sensor output starts to increase from the tip a of the concave portion 9,
It can be seen that the sensor 2 starts to descend at the rear end b, and that an output is obtained from the sensor 2 corresponding to the concave portion 9 provided on the surface of the disk 1b. The quality of the output signal was the same as that of the information signal in the conventional magnetic recording system.

FIG. 10 shows the result of measurement of the deviation of the sensor 2 from the track while the disk 1b makes one revolution under the tracking control. From FIG. 10, it can be confirmed that the error of the sensor 2 from the track is 5% or less of the track width, and is within about 5% of the sensor width formed narrower than the track width. This is equivalent to the accuracy of tracking control performed using a conventional positioning signal. The time on the horizontal axis is standardized and corresponds to one round of the disk with a numerical value of 100.

[0043] Example 3 Example 3 A disk 1c provided with protrusions 4 corresponding to the information on the substrate as shown in FIG. 11, slightly away to the top of the convex portion 4, thermal energy Is a read-only information recording medium for reading pre-recorded information by scanning the sensor 2 formed of a resistor provided with the information.

The protrusions 4 are formed using a stamper so as to have a height of 30 nm when the disk 1c is formed of resin. Thereafter, a carbon layer having a self-lubricating action was formed as a protective layer on the substrate by a sputtering method, and a lubricant was applied. In addition, the method of forming the protrusion 4 is not limited to the above-described method, and may be formed by etching using a glass disk, for example. The protective layer is not limited to the carbon layer and may be a silicon-based material.

Further, for example, tantalum can be used as a material of the sensor 2, but the material is not limited to this, and a resistor such as permalloy or copper may be used. However, in order to increase the detection sensitivity, a material having a large resistance change due to heat is preferable.
The width of the sensor 2 is, for example, 2.5 μm and its resistance value is 30Ω.
It is formed so that The constant current flowing through the sensor 2 is 14 mA. The slider 3 on which the sensor 2 is mounted is a negative pressure slider type, and the flying height of the slider 3 is 50 nm.
And The flying height of 50 nm prevents the flying attitude of the slider 3 from fluctuating when the sensor 2 passes over the convex portion 4, thereby preventing the slider 3 from losing its balance and falling off.
This is to ensure that heat is sufficiently transferred from the sensor 2 to the projection 4.

FIG. 11 shows waveforms obtained by conducting an information reading experiment in the above-described configuration of the disk 1c and the sensor 2. In the figure, since the heat radiation from the resistor increases in the convex portion 4, the sensor output starts to decrease from the tip a of the convex portion 4,
It starts to rise at the rear end b, and it can be seen that an output is obtained from the sensor 2 corresponding to the convex portion 4 provided on the surface of the disk 1c. The quality of the output signal was the same as that of the information signal in the conventional magnetic recording system.

FIG. 12 shows the result of measurement of the deviation of the sensor 2 from the track while the disk 1c makes one revolution under the tracking control. From FIG. 12, it can be confirmed that the error of the sensor 2 from the track is 5% or less of the track width, and is within about 5% of the sensor width formed narrower than the track width. This is equivalent to the accuracy of tracking control performed using a conventional positioning signal. The time on the horizontal axis is standardized and corresponds to one round of the disk with a numerical value of 100.

Therefore, as described above, from the description of the first to third embodiments according to the first embodiment, the uneven portion for exchanging thermal energy with the sensor is provided on the substrate, and the uneven portion is provided with the information in advance. Thus, a read-only information recording medium using an inexpensive resin material can be configured. In addition, since an injection molding method can be used to form irregularities on the substrate, a disk can be manufactured at low cost, and a disk can be reproduced by a sensor using a resistor, so that an inexpensive disk system can be configured. .

Second Embodiment In a second embodiment, position information such as a signal for tracking control and a positioning signal is constituted by the same concave and convex portions as those described in the first embodiment. The present invention relates to an information recording medium having an area in which information can be recorded, and an information detecting device that detects position information of the information with a resistor sensor and performs position control. Therefore, the information recording medium according to this embodiment is different from the first embodiment in that a head for recording and reproducing information on a track is integrated with a sensor to record and reproduce information at high density. It is possible to do.

FIG. 13 shows an example of the configuration of the system according to the second embodiment. The disk 1, which is an information recording medium capable of recording and reproduction, is rotated by a spindle motor 6 in a direction indicated by an arrow R at a predetermined rotation speed. The sensor 2 is mounted on a slider 3. The slider 3 is mounted on the tip of an arm 7, and the other end of the arm 7 is mounted on an arm driving device 8 and is rotatable. After the output from the sensor 2 is detected as position information by a positioning signal detection circuit 15, the positioning signal is restored by a positioning signal processing circuit 16, and the positioning signal is input to a control circuit 13 and sent to a spindle motor 6 via a driver 14. Is input to the arm driving device 8 and the like to control the rotation speed, tracking, and the like.

An embodiment of the disk 1 according to the second embodiment and an example of signal detection by the sensor 2 corresponding thereto will be described below. 7 to 12 can be applied to the description of the present embodiment by partially rewriting the description of the first embodiment, and these drawings will also be referred to as appropriate. In the following description, a magnetic recording medium will be described as a medium. However, the present invention is not limited to this, and may be used for an optical recording medium, a magneto-optical recording medium, and the like.

Fourth Embodiment A fourth embodiment is a disk 1a in which the projections 4 shown in FIG. 7 are formed only in correspondence with the positioning signal. It is an information recording medium capable of reading and recording a recorded positioning signal.

The protrusions 4 are formed using a stamper so as to have a height of 80 nm when the disk 1a is formed of resin. After that, a magnetic layer is formed on the substrate by a sputtering method. In addition, the method of forming the protrusion 4 is not limited to the above-described method, and may be formed by etching using a glass disk, for example. In addition, a nickel alloy, an iron alloy, or the like may be used for the magnetic layer in addition to the cobalt alloy.

An MR element was used as the material of the sensor 2. The resistance of the MR element changes due to a magnetic signal.
An element that can read out a magnetic signal by electrically detecting this change. A magnetic signal in which information is recorded, and a thermal signal in which a positioning signal is recorded due to unevenness. Can be detected by one element.

The width of the MR element of the sensor 2 is, for example, 2.5 μm.
m, and the constant current flowing therethrough is 14 mA. Sensor 2
Is mounted on the disk 3a using a negative pressure slider type, the flying height of the slider 3 is set to 50 nm, and the sensor 2 is brought into contact with the above-mentioned convex portion 4 formed on the disk 1a. When the sensor 2 comes into contact with the disk, the flying height of the slider 3 changes, and
This is to prevent the sensor from falling off due to the imbalance, and to ensure that the contact between the sensor 2 and the convex portion 4 of the disk 1a is sufficiently obtained.

In the configuration of the disk 1a and the sensor 2 described above, the waveform of the position information readout experiment was similar to that shown in FIG. From FIG. 7, it can be seen that an output is obtained from the sensor 2 corresponding to the projection 4 provided on the surface of the disk 1a. The quality of the output signal was the same as that of the information signal in the conventional magnetic recording system.

In the state where the tracking control is performed, the disk 1
The measurement result of the deviation of the sensor 2 from the track during one rotation of a is the same as that in FIG. From FIG. 8, the error of the sensor 2 from the track is 5% or less of the track width, and 5% of the sensor width formed narrower than the track width.
It can be confirmed that it is within the range. This is equivalent to the accuracy of tracking control performed using a conventional positioning signal.

Fifth Embodiment A fifth embodiment is a disk 1b in which the concave portion 9 shown in FIG. 9 is formed only in correspondence with the positioning signal. Is a recordable and reproducible information recording medium for reading position information recorded in advance by scanning.

The concave portion 9 is formed by using a stamper so as to have a depth of 200 nm when the disk 1b is formed of resin. Thereafter, a magnetic layer was formed on the substrate by a sputtering method. Note that the method of forming the concave portion 9 is not limited to the above-described method, and may be formed by, for example, etching using a glass disk. For the magnetic layer, a nickel alloy, an iron alloy or the like can be used in addition to the cobalt alloy. Further, an MR element was used as a material of the sensor 2.

The width of the MR element is, for example, 2.5 μm, and the constant current flowing therethrough is 14 mA. The slider 3 on which the sensor 2 is mounted is a negative pressure slider type, and the flying height of the slider 3 is 50 nm. The flying height of 50 nm prevents the slider 3 from fluctuating in height when the sensor 2 passes over the recess 9, thereby preventing the slider 3 from losing its balance and falling off, and transferring heat from the sensor 2 to the recess 9. This is to ensure that the operation is performed sufficiently.

In the configuration of the disk 1b and the sensor 2 described above, the waveform obtained by performing the position information readout experiment was similar to that shown in FIG. From FIG. 9, it can be seen that an output is obtained from the sensor 2 corresponding to the concave portion 9 provided on the surface of the disk 1b. The quality of the output signal was the same as that of the information signal in the conventional magnetic recording system.

The disk 1 is controlled in a tracking-controlled state.
The measurement result of the deviation of the sensor 2 from the track during one round of b is the same as that in FIG. According to FIG.
Is less than 5% of the track width,
It can be confirmed that the width is about 5% of the width of the sensor formed narrower than the track width. This is equivalent to the accuracy of tracking control performed using a conventional positioning signal.

Embodiment 6 Embodiment 6 is a disk 1c in which the projections 4 shown in FIG. 11 are formed only in correspondence with the positioning signal. This is an information recording medium that can record and reproduce information by reading position information recorded in advance by scanning a sensor 2 made of a given resistor.

The protrusions 4 are formed using a stamper so as to have a height of 30 nm when the disk 1c is formed of resin. Thereafter, a magnetic layer was formed on the substrate by a sputtering method. In addition, the method of forming the protrusion 4 is not limited to the above-described method, and may be formed by etching using a glass disk, for example. For the magnetic layer, a nickel alloy, an iron alloy or the like can be used in addition to the cobalt alloy. Further, an MR element was used as a material of the sensor 2.

The width of the MR element is, for example, 2.5 μm, and the constant current flowing therethrough is 14 mA. The slider 3 on which the sensor 2 is mounted is a negative pressure slider type, and the flying height of the slider 3 is 50 nm. The flying height of 50 nm prevents the slider 3 from fluctuating in height when the sensor 2 passes over the convex portion 4, thereby preventing the slider 3 from losing its balance and falling off. This is in order to ensure that the movement is sufficiently performed.

In the configuration of the disk 1c and the sensor 2 described above, the waveform of the experiment for reading the position information is shown in FIG.
Was similar to It can be seen from FIG. 11 that an output is obtained from the sensor 2 corresponding to the projection 4 provided on the surface of the disk 1c. The quality of the output signal was the same as that of the information signal in the conventional magnetic recording system.

In the state where the tracking control is performed,
The measurement result of the deviation of the sensor 2 from the track during one rotation of c was the same as that in FIG. As shown in FIG.
Is less than 5% of the track width,
It can be confirmed that the width is about 5% of the width of the sensor formed narrower than the track width. This is equivalent to the accuracy of tracking control performed using a conventional positioning signal.

In the above-described fourth to sixth embodiments, it goes without saying that separate sensors for exclusively detecting the magnetic signal and the thermal signal may be provided.
It is necessary to keep the positional relationship between the individual sensors constant at all times.

It is natural that a GMR element having higher sensitivity may be used instead of the MR element.

Further, the present invention is not limited to a disc-shaped information recording medium, but may be used for a card-shaped information recording medium, a band-shaped information recording medium, or the like. When the present invention is applied to a card-shaped or band-shaped information recording medium, it is needless to say that it is necessary to have a configuration of a unique device for securing the relative positional relationship between the information recording medium and the sensor and performing scanning.

[0071]

As is apparent from the above description, the present invention eliminates recording bleeding due to magnetic recording due to a positioning signal, occurrence of an erase band, and non-uniformity between tracks, which were problems in conventional magnetic recording. Therefore, it is possible to provide a read-only information recording medium having a good S / N and a high density and an information detecting device thereof, and an information recording medium capable of recording and reproducing and an information detecting device thereof.

Further, since the position information of the irregularities is created at the same time as the formation of the disk, it is not necessary to write a positioning signal anew after manufacturing the disk, as in the case of a magnetic disk, and the information must be reproduced by a resistor. So you can
An extremely inexpensive medium and disk device can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between a projection provided on an information recording medium and an output from a sensor according to the present invention.

FIG. 2 is a schematic diagram illustrating a configuration of a signal detection circuit.

FIG. 3 is a diagram showing an arrangement of data zones and servo zones of a disc-shaped information recording medium according to the present invention.

FIG. 4 is a schematic diagram showing an information pattern of an information recording medium according to the present invention.

FIG. 5 is an enlarged view of a main part of an information pattern.

FIG. 6 is a schematic diagram showing a reproduction system of a disk-shaped read-only information recording medium according to the first embodiment of the present invention.

FIG. 7 is a diagram for describing signal detection according to the first embodiment according to the first embodiment of the present invention.

FIG. 8 is a measurement diagram showing the accuracy of tracking according to the first embodiment.

FIG. 9 is a diagram for explaining signal detection of Example 2 according to the first embodiment of the present invention.

FIG. 10 is a measurement diagram showing the accuracy of tracking according to the second embodiment.

FIG. 11 is a diagram for explaining signal detection of Example 3 according to the first embodiment of the present invention.

FIG. 12 is a measurement diagram illustrating tracking accuracy in the third embodiment.

FIG. 13 is a schematic diagram showing a reproduction system of a disc-shaped recordable information recording medium according to a second embodiment of the present invention.

[Explanation of symbols]

1, 1a, 1b, 1c: disk, 2: sensor, 3: slider, 4: convex portion, 5: constant current power supply, 6: spindle motor, 7: arm, 8: arm drive device, 9: concave portion, 1
DESCRIPTION OF SYMBOLS 1 ... Signal detection circuit, 12 ... Signal processing circuit, 13 ... Control circuit, 14 ... Driver, 15 ... Positioning signal detection circuit,
16 positioning signal processing circuit 17 information recording / reproducing circuit 20 servo zone 21 data zone

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // G11B 5/02 G11B 5/02 U H01L 43/08 H01L 43/08 Z

Claims (19)

[Claims] 1. An information recording medium having a projection or a depression corresponding to information formed on a substrate, wherein heat energy is exchanged between the projection or the depression of the information recording medium and the detector. An information recording medium characterized in that the recording information is read out by performing the operation. 2. An apparatus for reading information recorded on an information recording medium according to claim 1, wherein said detector is constituted by a detecting member whose resistance value changes by exchanging thermal energy. Information detection device. 3. A slider provided with the detecting member is provided on the information recording medium having a convex portion corresponding to information according to claim 1, wherein the detecting member contacts the convex portion of the information recording medium. 3. The information detecting apparatus according to claim 2, wherein heat energy is exchanged to change a resistance value of the detection member, and information is detected based on the changed resistance value. . 4. A slider having a detecting member to which thermal energy is continuously supplied is provided on an information recording medium having a convex portion or a concave portion corresponding to information according to claim 1, wherein said detecting member is provided with said information member. Heat energy is exchanged by running the recording medium over the convex portion or the concave portion slightly apart from the concave portion, the resistance value of the detection member changes, and information is detected based on the changed resistance value. The information detection device according to claim 2, wherein the information detection device has a configuration. 5. The information detecting device according to claim 4, wherein a flying height variation of the slider flying above the information recording medium is within 5% of the flying height. 6. The information recording medium according to claim 1, wherein the information recording medium has a disk shape. 7. The information recording medium according to claim 1, wherein the information recording medium has a card shape. 8. An information recording medium having a convex portion or a concave portion corresponding to position information formed on a substrate and further having a recordable / reproducible region, wherein the information is detected as a convex portion or a concave portion of the information recording medium. An information recording medium having a configuration in which positional information is read out by exchanging thermal energy with a container. 9. The apparatus according to claim 8, wherein the detector comprises a detecting member whose resistance value changes by exchanging thermal energy. Information detection device. 10. The information detecting apparatus according to claim 9, wherein said detecting member is an MR element. 11. The information detecting device according to claim 9, wherein said detecting member is a GMR element. 12. A slider provided with the detecting member is provided on the information recording medium having a convex portion corresponding to position information according to claim 8, wherein the detecting member contacts the convex portion of the information recording medium. 10. The information according to claim 9, wherein heat energy is exchanged to change a resistance value of the detection member, and positional information is detected based on the changed resistance value. Detection device. 13. A slider having a detecting member to which thermal energy is continuously supplied is provided on an information recording medium having a convex portion or a concave portion corresponding to positional information according to claim 8, wherein said detecting member is provided with said detecting member. Heat energy is exchanged by running slightly above the convex or concave portion of the information recording medium to change the resistance value of the detection member, and position information is detected based on the changed resistance value. The information detecting device according to claim 9, wherein the information detecting device is configured to perform the following. 14. The information detecting device according to claim 13, wherein a flying height variation of the slider flying above the information recording medium is within 5% of the flying height. 15. The information recording medium according to claim 8, further comprising a magnetic recording layer, wherein recording and reproduction of information in the recordable / reproducible area are performed by magnetic means. 16. The information recording medium according to claim 8, further comprising an optical recording layer, wherein information recording and reproduction in the recordable / reproducible area are performed by optical means. 17. The information recording medium according to claim 8, comprising a magneto-optical recording layer, wherein recording and reproduction of information in said recordable / reproducible area is performed by magneto-optical means. 18. The information recording medium according to claim 8, wherein the information recording medium has a disk shape. 19. The information recording medium according to claim 8, wherein the information recording medium has a card shape.