JPH10255209A - Information recording / reproducing device - Google Patents

Abstract

(57) Abstract: The present invention relates to an information recording / reproducing device such as a hard disk device, and more particularly to a highly reliable information recording device capable of preventing information loss due to thermal fluctuation while achieving a high recording density. It is to provide a device. An information recording / reproducing apparatus according to the present invention is a magnetic recording / reproducing apparatus, wherein each information recorded on a recording medium is:
The elapsed time or the elapsed time and the temperature change after being recorded on the recording medium are measured, and when these reach a predetermined value, information reaching the predetermined value is recorded again.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an information recording / reproducing device such as a hard disk device.

[0002]

2. Description of the Related Art In recent years, magnetic recording / reproducing devices such as hard disk drives have been widely used in the field of computers as large-capacity external storage devices that can be accessed at random. With the expansion of usage, demands for a large storage capacity and a high recording density are increasing.
Therefore, research and development are being carried out from various fields in order to meet such demands.

In general, as a hard disk device, a plurality of magnetic disks each having a magnetic layer provided on a non-magnetic substrate are stacked and mounted on one rotating shaft, and a recording / reproducing head is mounted on an arm to mount each disk. 2. Description of the Related Art There is known a structure in which an arm is arranged on a surface and an arm is moved by an actuator to position a head. When recording and reproducing information with a hard disk device having such a structure, the head does not directly contact the disk surface rotating at a high speed, but accesses a desired position on the disk surface while slightly floating. Are located. Then, information is recorded on or reproduced from the concentric tracks on the disk surface by the head.

In the above-mentioned hard disk drive, in order to meet the demand for a large storage capacity, for example, the recording density is improved by increasing the linear recording density of the disk, that is, the density in the track length direction, or the track density is increased. Attempts have been made to increase the recording density by narrowing the width and increasing the track density.

In recent years, research and development of magnetic materials for media, such as thinning of recording media, high coercive force, miniaturization of magnetic particles, etc., have been promoted in order to increase the recording density. Alternatively, development of contact recording that records and reproduces a signal almost in contact with a recording medium has also been performed.

In order to increase the sensitivity of signal reproduction, active heads such as MR heads utilizing the magnetoresistance effect have been actively developed. The MR head is a head that converts the magnetic flux from a recording medium into an electric signal using the property that the electric resistance of a soft magnetic material such as permalloy changes according to an external magnetic field. Since the reproducing sensitivity of the head is proportional to the magnitude of the sense current flowing through the soft magnetic material in order to convert a resistance change into a voltage change, a large output can be obtained even when the relative speed between the head and the medium is small. The reproducing MR head and the recording induction type head are formed so as to overlap each other with a certain interval on the slider after decoding.

In order to increase the signal-to-noise ratio (S / N) and improve the recording density, it is necessary to make the magnetic particles of the recording medium finer. However, miniaturization of the magnetic particles makes the magnetization of each particle more susceptible to a thermal disturbance, and causes a thermal fluctuation phenomenon in which the magnetization is attenuated with time. The thermal fluctuation phenomenon of the magnetic particles can be suppressed by increasing the magnetic anisotropy of the magnetization, but in this case, the coercive force of the recording medium increases, and it becomes very difficult to record, Even saturation recording can be difficult. It is known that this thermal fluctuation phenomenon becomes more remarkable at high temperatures and increases its influence.

Therefore, in the conventional magnetic recording / reproducing apparatus, by miniaturizing the magnetic particles for higher density, the magnetization tends to fluctuate due to heat, and the magnetization recorded as a signal attenuates with time. In addition, the recorded information may not be reproduced, and if the magnetic anisotropy of the magnetization is increased in order to avoid attenuation, there is a problem that it becomes difficult to record the information.

[0009]

As described above, in the conventional magnetic recording / reproducing apparatus, the magnetization is easily fluctuated by heat by miniaturizing the magnetic particles to increase the density, and the signal is recorded as a signal. In addition, there is a risk that the recorded magnetization may be attenuated with time and the recorded information may not be reproduced, and that if the magnetic anisotropy of the magnetization is increased to avoid the attenuation, it becomes difficult to record the information. . SUMMARY OF THE INVENTION It is an object of the present invention to provide a highly reliable magnetic recording / reproducing apparatus capable of preventing information loss due to thermal fluctuation while achieving high recording density.

[0010]

In order to solve the above problems, an information recording apparatus of the present invention has a recording medium on which information can be recorded magnetically, and a recording medium for recording the information on the recording medium. An information recording / reproducing apparatus having a head and a reproducing head for reproducing information from the recording medium, wherein each information recorded on the recording medium is measured for an elapsed time since the information was recorded on the recording medium. Measuring means, comprising a time lapse determining means for detecting whether or not the elapsed time by the measuring means has passed a predetermined time, information that the predetermined time has been detected by the time lapse determining means, The recording is performed again by the recording head.

Further, the present invention has a recording medium on which information can be recorded by magnetism, a recording head for recording the information on the recording medium, and a reproducing head for reproducing information from the recording medium. An information recording / reproducing device,
Elapsed time measuring means for measuring an elapsed time since each piece of information recorded on the recording medium is recorded on the recording medium; temperature change measuring means for measuring a temperature change of the recording medium; A time temperature integrated value calculating means for calculating a time temperature integrated value from the temperature change by the measuring means and the elapsed time based on the elapsed time measurement time; and whether the time temperature integrated value by the time temperature integrated value calculating means has reached a predetermined value. Time temperature integrated value judging means for judging whether the predetermined value has been reached by the time temperature integrated value judging means is recorded again by the recording head.

Further, the temperature change measuring means includes a magnetoresistive element. Furthermore, a magnetoresistive element is provided as the temperature change measuring means.

Further, a magneto-resistance effect element is used as the reproducing head, and the magneto-resistance effect element is used as the temperature change measuring means.
It is characterized in that a time-temperature integrated function storage means for storing the time-temperature integrated value as a function depending on time change of time and temperature is provided.

According to the present invention, it is detected that the elapsed time or the time-temperature integrated value calculated from the temperature change and the elapsed time has reached a predetermined value so that the record information does not always elapse a certain time, By re-recording information by this detection, while achieving high recording density,
Information loss due to thermal fluctuation can be prevented.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a configuration of an information recording apparatus according to one embodiment of the present invention. The magnetic head 1 is disposed at the tip of an actuator arm 2 that is driven to rotate, and records and reproduces a signal (information) on a recording track 4 of a rotating disk-shaped recording medium 3. This information recording / reproducing apparatus integrates a recording medium 3 capable of magnetically recording a signal, a recording head for recording a signal on the recording medium 3 and a reproducing head for reproducing a magnetic signal from the recording medium. An information recording device having the magnetic head 1 formed.

(Embodiment 1) FIG. 2 is a block diagram for explaining functions relating to the information recording apparatus of the present invention. The information recording apparatus 200 includes, for example, a non-volatile memory 5 as a memory for storing a time at which the information is recorded for each information recording unit recorded on the recording medium 3, and a hard disk controller (hereinafter, referred to as a memory) for controlling the information recording / reproducing operation. HDC)
6 and a microprocessor (hereinafter, MPU) for controlling the entire hard disk drive including servo control and signals.
7). When information is recorded on the recording track 4 on the recording medium 3 via the channel IC 8 and the head IC 9, the time of recording (information recording time) is recorded for each recording information unit by the host interface 1.
0, for example, an external personal computer (P
C) It is provided as time information from a built-in clock, and is stored in the nonvolatile memory 5 together with the information recording time and address information for specifying the recorded information.

The servo signal information obtained from the magnetic head 1 is a PES (Position Error Sign).
al) The demodulator 11 converts the information into position error information,
7, DA (Digital) is used as positioning control information.
A voice coil motor (VCM (VCM)) that drives the actuator 2 via a to analog converter 12
oice Coil Motor)), and drives the VCM. The rotation control signal of the recording medium 3 is transmitted from the MPU 7 to the spindle driver 15 via the spindle controller 14, and controls the rotation of the spindle motor 16.

The information recording time stored in the non-volatile memory 5 is monitored by an elapsed time measuring unit 17 (for example, a timer), compared with the current time provided via the host interface 10, and the information is recorded on a recording medium. 3 is calculated. Elapsed time judgment unit 1
Numeral 8 compares the elapsed time calculated by the elapsed time measuring unit 17 with a preset time, detects that the time to be re-recorded has elapsed, and notifies the HDC 6.
The elapsed time to be re-recorded can be arbitrarily set in advance in the elapsed time determination unit 18 according to the recording medium to be used and the use environment. For example, a time such as 6 months or 12 months can be input. it can. Note that the elapsed time is stored in the ROM (Read
(Only Memory), or may be arbitrarily input from an external personal computer via the host interface 10.

A signal for requesting re-recording is sent to an elapsed time judgment section 18.
The received HDC 6 reproduces the recording information of the corresponding recording area on the recording medium 3 by the magnetic head 1, temporarily stores the information in the buffer 19, and returns to the same recording area or a different empty area on the recording medium 3 again. Record the same. At this time, the time when this information is re-recorded is similarly stored in the nonvolatile memory 5.

The old information recording time of the re-recorded information may be rewritten. Further, by performing the re-recording process at a timing when there is no recording or reproduction access request to the disk, the data transfer performance of the disk is not adversely affected. Further, the processing of the elapsed time determination unit 18 may be performed by the MPU 7. Although the current time is input from the outside through the host interface 10, a clock may be built in the hard disk device 200 and this clock may be used.

Thus, even if a thermal fluctuation phenomenon in which the recorded signal attenuates with time occurs, re-recording is performed before an error is caused by signal attenuation due to the thermal fluctuation,
The effect of thermal fluctuation can be suppressed, and an information recording apparatus having a high recording density and high data reliability can be provided.

(Embodiment 2) FIG. 3 is a block diagram illustrating functions of an information recording apparatus according to a second embodiment of the present invention. The information recording device 300 includes a temperature sensor 20 that is disposed near the recording medium 3 and measures the temperature near the recording medium 3;
A temperature history measurement unit 21 for measuring a time change of temperature, a non-volatile memory 5 as a memory for storing the time and temperature history of the information recording unit for each information recording unit recorded on the medium, An elapsed time measuring unit 23 for measuring an elapsed time since the operation was performed; and a time temperature integration for calculating an integrated value of the temperature and the elapsed time measured by the temperature sensor 20 and determining whether or not a predetermined value has been reached. It has a judging unit 22, an HDC 6 for controlling the recording / reproducing operation, and an MPU 7 for controlling the entire hard disk device including servo control and signals. In FIG. 3, the portions related to the servo control are the same as those in the first embodiment, and illustration and description are omitted.

When information is recorded on the recording track 4 on the recording medium 3 via the channel IC 8 and the head IC 9, the time at which the information was recorded (information recording time) for each recording information unit is determined by the host and the host. The information is stored in the non-volatile memory 5 based on time information provided from, for example, a clock incorporated in an external personal computer (PC) via the interface 10. The information recording time stored in the non-volatile memory 5 is monitored by the elapsed time measuring unit 17, compared with the current time provided via the host interface 10, and after the information is recorded on the recording medium 3. The elapsed time is calculated. The temperature history measurement unit 21 transmits the temperature information obtained from the temperature sensor 20 to the host interface 10.
Is replaced with a numerical value together with the time provided via the non-volatile memory 5. The temperature history measurement unit 21 selects an appropriate temperature measurement method from the average temperature within a certain period, the maximum temperature within a certain period, the instantaneous temperature at each certain period, and measures the temperature history over time. Time temperature integration judgment unit 2
2 is stored in the time temperature integration function storage unit 30 for each recording information unit based on the elapsed time calculated by the elapsed time measurement unit 23 and the temperature change measured by the temperature history measurement unit 21. The integrated value of time and temperature is calculated by using the function. Here, the time temperature product value is
When temperature T [° K] and time t (sec), T ×
1n (t). Assuming that the temperature of a certain period Δti changes to Ti = 1, 2,..., N, the time-temperature integration function storage unit 30 stores Σ ｛Ti × 1n (Δt
i) A function that can be represented by｝ is stored. The time temperature integration determining unit 22 compares the time temperature integrated value with a preset time temperature integrated limit value, detects that the time to be re-recorded has elapsed, and notifies the HDC 6. The time-temperature integrated value to be re-recorded is stored in the time-temperature integrated function storage unit 3 according to the recording medium to be used and the use environment.
It can be arbitrarily set to 0 in advance.

The HDC 6, which has received a signal for re-recording from the time-temperature integration judging unit 22, reproduces the recording information of the corresponding recording area on the recording medium 3 by the magnetic head 1 and temporarily stores the information in the buffer 19. Then, the same recording is performed again in the same recording area or a different free area on the recording medium 3.
At this time, the time when this information is re-recorded is similarly stored in the nonvolatile memory 5. The old information recording time for the re-recorded information may be rewritten. Also, by performing the re-recording process at a timing when there is no recording or reproduction access request to the disc,
The data transfer performance of the disk is not adversely affected.

As a result, similarly to the first embodiment, even if a thermal fluctuation phenomenon occurs in which the recorded signal attenuates with time, re-recording is performed before an error is caused by the signal attenuation due to the thermal fluctuation, and the thermal fluctuation is performed. Therefore, it is possible to provide an information recording apparatus having a high recording density and high data reliability even in a temperature environment where the influence of thermal fluctuation is large.

(Embodiment 3) FIG. 4 is a block diagram for explaining functions of an information recording apparatus according to a third embodiment of the present invention. The information recording apparatus includes an MR (magnetoresistive effect) reproducing element 24 mounted on the magnetic head 1 for measuring the temperature in the vicinity of the recording medium 3, a temperature history measuring unit 21 for measuring a time change of the temperature, A non-volatile memory 5 for storing the time and temperature history at which the information was recorded for each information recording unit recorded in the memory, an elapsed time measuring unit 23 for measuring an elapsed time since each piece of information was recorded, and an MR reproducing element A time temperature integration determining unit 22 that calculates the integrated value of the temperature measured in 24 and the elapsed time and determines whether the temperature has reached a predetermined value.
And an HDC 6 for controlling the recording / reproducing operation, and an MPU 7 for controlling the entire hard disk drive including servo control and signals. In FIG. 3, the portions related to the servo control are the same as those in the first embodiment, and illustration and description are omitted.

When information is recorded on the recording track 4 on the recording medium 3 via the channel IC 8 and the head IC 9, the time at which the information was recorded (information recording time) is set for each recording information unit by the host. The information is stored in the nonvolatile memory 5 based on time information provided from, for example, a clock built in an external personal computer via the interface 10. The information recording time stored in the non-volatile memory 5 is monitored by the elapsed time measuring unit 17, compared with the current time provided via the host interface 10, and after the information is recorded on the recording medium 3. The elapsed time is calculated. The temperature history measuring unit 21 includes an MR reproducing element 24
The temperature information obtained from the electric resistance value R is replaced with a numerical value together with the time provided by the host interface 10 and stored in the nonvolatile memory 5. The temperature history measuring unit 21 measures the electric resistance value R (= Vdc / Is) from the voltage Vdc between both ends of the MR reproducing element 24 and the sense current Is, and also measures the temperature and the temperature which have been measured and stored in advance.
Convert the temperature into a temperature using the correlation curve of the electrical resistance value, select an appropriate temperature measurement method from the average temperature within a certain period, the maximum temperature within a certain period, the instantaneous temperature at a certain period, etc. measure. Time temperature integration judgment unit 22
Is the elapsed time calculated by the elapsed time measuring unit 23,
Based on the temperature change measured by the temperature history measurement unit 21, the integrated value of time and temperature is calculated for each recording information unit using the function stored in the time-temperature integration function storage unit 30. .

Here, the time temperature integrated value is the temperature T [°
K] and time t (sec), T × 1n (t)
Can be calculated. The temperature for a certain period Δti is set to Ti
Assuming that i = 1, 2,..., N,
The time temperature integration function storage unit 30 stores a function that can be expressed as {Ti × 1n (Δti)} as a function for obtaining the time temperature integration value. The time temperature integration determination unit 22 compares the time temperature integrated value with a preset time temperature integrated limit value, detects that the time to be re-recorded has elapsed, and notifies the HDC 6. The elapsed time to be re-recorded can be arbitrarily set in advance in the time-temperature integration determining unit 22 according to the recording medium to be used and the use environment. For example, time temperature integrated value Σ ｛Ti × 1n
(Δti)｝ is room temperature (300 ° K), 5 years (1n
(T) = 18.88), which can be set to the value 5664, and this value is determined by the nonvolatile memory 5 or the time / temperature integration determining unit 2 according to the maximum recording density and data zone to be used.
2 can be finely set by using a numerical table or the like stored in the memory 2.

The HDC 6 having received the signal for re-recording from the time-temperature integration judging section 22 reproduces the recording information of the corresponding recording area on the recording medium 3 by the magnetic head 1 and temporarily stores the information in the buffer 19. Then, the same recording is performed again in the same recording area or a different free area on the recording medium 3.
At this time, the time when this information is re-recorded is similarly stored in the nonvolatile memory 5. The old information recording time for the re-recorded information may be rewritten. In addition, by performing the re-recording process at a timing when there is no recording or reproduction access request to the disc,
The data transfer performance of the disk is not adversely affected.

Thus, as in the case of the first and second embodiments, even if a thermal fluctuation phenomenon occurs in which the recorded signal attenuates with time, re-recording is performed before an error is caused by signal attenuation due to the thermal fluctuation. The influence of thermal fluctuation can be suppressed, and an information recording apparatus having a high recording density and high data reliability can be provided even in a high temperature environment where the thermal fluctuation has a large influence.

[0031]

According to the present invention, even if a thermal fluctuation phenomenon occurs in which a recorded signal attenuates with time, the recorded information is re-recorded before an error is caused by the signal attenuation due to the thermal fluctuation. It is possible to suppress the influence of fluctuation, and to provide an information recording apparatus having a high recording density and high data reliability even when used in a high-temperature environment where the influence of thermal fluctuation is large.

[Brief description of the drawings]

FIG. 1 is a partial sectional perspective view of an information recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of an information recording apparatus according to a first embodiment of the present invention.

FIG. 3 is a schematic diagram of an information recording device according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram of an information recording apparatus according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Magnetic head 2 ... Actuator 3 ... Recording medium 4 ... Recording track 5 ... Non-volatile memory 6 ... HDC (hard disk controller) 7 ... MPU (Microprocessor) 8 ... Channel IC 9 ... Head IC 10 ... Host interface 11 ... PES Demodulator 12 ... D / A converter 13 ... VCM driver 14 ... Spindle controller 15 ... Spindle driver 16 ... Spindle motor 17 ... Elapsed time measurement unit 18 ... Elapsed time judgment unit 19 ... Buffer 20 ... Temperature sensor 21 ... Temperature History measurement unit 22 Time / temperature integration determination unit 23 Elapsed time measurement unit 24 MR / MR (magnetoresistive) reproducing element 30 Time / temperature integration function storage unit 130 VCM 200, 300, 400 Hard disk device

Claims (5)

[Claims] An information recording / reproducing apparatus comprising: a recording medium on which information can be recorded by magnetism; a recording head for recording the information on the recording medium; and a reproducing head for reproducing information from the recording medium. And measuring means for measuring an elapsed time since each piece of information recorded on the recording medium is recorded on the recording medium; and determining whether an elapsed time by the measuring means has passed a predetermined time. An information recording / reproducing apparatus, comprising: a time lapse determining means for detecting the information; and information recorded by the time lapse determining means that the predetermined time has elapsed is recorded by the recording head again. 2. An information recording / reproducing apparatus comprising: a recording medium on which information can be recorded by magnetism; a recording head for recording the information on the recording medium; and a reproducing head for reproducing information from the recording medium. Wherein each piece of information recorded on the recording medium is an elapsed time measuring unit that measures an elapsed time after being recorded on the recording medium, and a temperature change measuring unit that measures a temperature change of the recording medium. The time temperature integrated value calculating means for calculating the time temperature settled value from the temperature change by the temperature change measuring means and the elapsed time based on the elapsed time measurement time, and the time temperature integrated value by the time temperature integrated value calculating means have reached a predetermined value. Time temperature integrated value determining means for determining whether or not a predetermined value has been reached by the time temperature integrated value determining means. Information recording and reproducing apparatus, characterized in that the degree recording. 3. An information recording / reproducing apparatus according to claim 2, wherein a magnetoresistance effect element is provided as said temperature change measuring means. 4. An information recording / reproducing apparatus according to claim 2, wherein a magnetoresistive element is used as said reproducing head, and said magnetoresistive element is used as said temperature change measuring means. 5. An information recording / reproducing apparatus according to claim 2, further comprising a time / temperature integration function storage means for storing the time / temperature integration value as a function depending on time and temperature. .