JP2004095010A - Disk device and control method based on its environmental temperature - Google Patents

Abstract

A hard disk drive that guarantees stable operation in a low-temperature environment is provided.
A first disk having a BPI adapted to an operation guaranteed temperature range (first operation guaranteed temperature range) and a BPI for ensuring stable operation in a low temperature environment (second operation guaranteed temperature range). A second disk 3B is provided. When the environmental temperature is equal to or higher than the minimum temperature T1 of the first operation guarantee temperature range, information is preferentially recorded on the first disk 3A, and the environment temperature is lower than T1 and the minimum temperature of the second operation guarantee temperature range. If the temperature is in the range of T2 or more, the information is recorded on the second disk 3B, and after the temperature rises to T1 or more, the information is recorded on the second disk 3B using the idle time of the hard disk drive 1 or the like. The current information is moved to the first disk 3A.
[Selection diagram] Fig. 4

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a disk device for reading and writing signals from and to a disk-shaped storage medium, and a method for optimally controlling the disk device according to an environmental temperature.
[0002]
[Prior art]
The operation guarantee temperature range of the disk device is, for example, about 5 ° C. to 55 ° C. In an environment at a temperature lower than the operation assurance temperature range, the coercive force (Hc) of the disk is increased and overwrite (OW) characteristics are deteriorated, and the distance between the disk and the element is increased due to the recess of the element of the magnetic head. Depending on the cause, there is a possibility that a defect that the bit error rate (BER) of the disk device deteriorates may occur.
[0003]
Therefore, measures have been considered for using the disk device in a low-temperature environment. Japanese Patent Application Laid-Open No. 2001-57010 discloses a known technique for solving the problem.
[0004]
The present invention provides a device for detecting a temperature in a device, a device for determining whether a temperature detected by the device is within an operation guarantee range of the device, and a device for detecting a temperature lower than the operation guarantee range. And means for raising the temperature inside the apparatus.
[0005]
[Problems to be solved by the invention]
However, in the above-described conventional technology, it takes time for the temperature inside the disk device to rise to the operation guarantee temperature range, and there is a problem that the use of the disk device is waited until that time, resulting in poor availability.
[0006]
The present invention has been made in order to solve the above-described problem, and can ensure stable operation in a low-temperature environment, and does not need to provide a restriction on use such as a temperature rise waiting time due to an internal heat source, and therefore, the availability of the present invention is improved. It is an object of the present invention to provide a disk device excellent in performance and a control method based on its environmental temperature.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a disk drive according to the present invention includes a first recording area having a BPI (linear recording density) adapted to a first operation guaranteed temperature range, and a center temperature higher than the first operation guaranteed temperature range. , A disk-shaped storage medium having a second recording area having a BPI adapted to a second operation assurance temperature range having a low temperature, read / write means for reading / writing signals from / to this storage medium, and temperature for detecting temperature A detection unit that, when the temperature detected by the temperature detection unit is equal to or higher than the lowest temperature of the first operation guarantee temperature range, performs writing to the first recording area preferentially by the read / write unit, and If the temperature is lower than the minimum temperature of the first operation assurance temperature range and equal to or higher than the minimum temperature of the second operation assurance temperature range, writing is performed by the read / write means in the second recording area. It is intended to and control means for controlled so.
[0008]
According to the present invention, it is possible to lower the low temperature guarantee limit temperature of the disk device to a temperature lower than the normal operation guarantee temperature range.
[0009]
Further, in the disk device of the present invention, when the control unit writes data to the second recording area by the read / write unit, the detected temperature may be equal to or higher than a minimum temperature of the first operation guarantee temperature range. After the height has risen, control may be performed to move recording information from the second recording area to the first recording area.
[0010]
According to the present invention, a recording area having a low BPI (linear recording density) must be secured in a disk-shaped storage medium in order to lower the low temperature guarantee limit temperature of the disk device to a temperature lower than the normal operation guarantee temperature range. By moving the recording information from the second recording area having a low BPI to the first recording area having a high BPI, the second recording area having a low BPI is used as a temporary recording area. Does not require large capacity. Therefore, based on the case where only the first recording area having a high BPI is used as a reference, the overall capacity reduction caused by replacing a part of the area with the second recording area having a low BPI is smaller than the effect obtained. Can not be a serious disadvantage.
[0011]
Further, in the disk device of the present invention, the first recording area and the second recording area may be set in units of a disk, or may be set in units of a signal recording surface of the disk. Alternatively, it may be set in one signal recording surface of the disc.
[0012]
The second recording area having a low BPI may be set in units of a disk, but may be set on one signal recording surface of the disk or a part of one signal recording surface of the disk. As a result, it is possible to further reduce the overall decrease in capacity due to the replacement of a part of the entire storage medium with the second recording area having a low BPI.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0014]
FIG. 1 is a perspective view showing a configuration of a hard disk drive 1 which is an embodiment to which the disk device of the present invention is applied.
[0015]
As shown in FIG. 1, the hard disk drive 1 includes a rectangular box-shaped case 2 having an open upper surface, and a top cover (not shown) screwed to the case with a plurality of screws to close the upper surface of the case 2. It has.
[0016]
In the case 2, for example, one or a plurality of disks (platters) 3, which are disk-shaped storage media, a spindle motor (SPM) 4 as a disk drive mechanism for supporting and rotating the disks 3, and a head actuator 6 are arranged. Here, the disk 3 employs, for example, a platter having a diameter of 65 mm (2.5 inches) and provided with magnetic recording layers on both surfaces.
[0017]
The head actuator 6 has a magnetic head slider 5 mounted with a head, which is an element for reading and writing signals to and from the disk 3, and a suspension 5a having a tab 9a that slides on a ramp 9 described later, and a suspension 5a having the suspension 5a at the distal end. A carriage constituted by laminating a plurality of head suspension assemblies (HSA) 15 comprising the supported arms 7, and the carriage being rotatable with respect to a bearing shaft 13 vertically provided on the bottom wall of the case 2. And a bearing unit 12 to be supported.
[0018]
Further, in the case 2, when the voice coil motor (VCM) 8 for driving the head actuator 6 and the magnetic head slider 5 move to the outer periphery of the disk 3, the head slides on the tab 9 a to move the head to the disk 3. A lamp unit 9 held at a predetermined evacuation position separated from the printer and a board unit 10 on which a head driver IC and the like are mounted are housed.
[0019]
A spindle motor (SPM) 4, a voice coil motor (VCM) 8, and a CPU, a memory, an HDD controller for controlling the head, A printed circuit board (not shown) on which other circuits are mounted is mounted by screws or the like.
[0020]
The voice coil motor (VCM) 8 includes a voice coil 17 fixed to a support frame 16 of the head actuator 6, a pair of yokes 18 fixed on the case 2 so as to sandwich the voice coil 17, and one yoke 18. And a fixed magnet 19.
[0021]
In the case 2, a temperature sensor (not shown) for detecting the temperature inside the hard disk drive 1 is arranged.
[0022]
FIG. 2 is a block diagram showing a system configuration of the hard disk drive 1.
[0023]
In the figure, a preamplifier circuit 21 has a read amplifier for amplifying a read signal read by a head 29 and a write amplifier for converting write data into a write current. The read / write (W / R) signal processing circuit 22 performs various signal processing such as A / D conversion processing, write data encoding processing, and read data decoding processing. A hard disk controller (HDC) 23 processes an interface between the hard disk drive 1 and a host system (a personal computer or a digital device), and performs, for example, read / write data transfer control.
[0024]
The motor driver 24 has a VCM driver 24A for driving the voice coil motor (VCM) 8 and an SPM driver 24B for driving the spindle motor (SPM) 4.
[0025]
The temperature sensor 28 transmits temperature information inside the hard disk drive 1 to the CPU 25.
[0026]
The CPU 25 is a main control device of the hard disk drive 1. For example, when writing a signal to the disk 3, the CPU 25 captures temperature information from the temperature sensor 28 and, based on the temperature information, performs different line recording as described below. Select a disk to record a signal from among two disks set with a density (BPI: bit per inch) or move data from a disk set with a lower BPI to a disk set with a higher BPI Control such as causing Here, the BPI is the number of bits per inch on one track, and when this BPI increases, the transfer speed from the disk 3 to the head 29 necessarily increases.
[0027]
The memory 26 includes a RAM and a flash EEPROM, and stores a control program of the CPU 25 and various parameters.
[0028]
FIG. 3 shows the correlation between the environmental temperature, the BPI, and the bit error rate (BER) in a certain hard disk drive. FIG. 3A shows the relationship between the BPI and the BER at an environmental temperature of 25 ° C. (operation guarantee temperature). The correlation (b) shows the correlation between BPI and BER at an ambient temperature of −20 ° C. (low temperature environment).
[0029]
BPI0 is a BPI that guarantees stable operation in an operation guarantee temperature range (for example, 5 ° C. to 55 ° C.). The horizontal axis of each of the graphs (a) and (b) indicates the value of BPI / BPI0.
[0030]
From these graphs, it can be seen that there is a correlation that BER decreases as BPI decreases. Further, from the relationship between BPIO and BER at the environmental temperature of 25 ° C. in (a), it can be said that the BER condition for guaranteeing the stable operation is about −5 (1 / 100,000) or less.
[0031]
The value of BPI / BPI0 that satisfies the BER condition that guarantees this stable operation under a low temperature environment (−20 ° C.) is around 0.8. In other words, if the BPI is lowered to about 0.8, the low temperature environment (− (20 ° C.).
[0032]
Of course, this value is an example when the low-temperature environment is -20 ° C. The BPI that guarantees stable operation in the low-temperature environment changes depending on the temperature setting of the low-temperature environment, and also differs depending on the head and media. Conceivable. Therefore, in actual operation, a low-temperature environment and a BPI that guarantees stable operation in this low-temperature environment are selected for each hard disk drive model.
[0033]
The hard disk drive 1 of this embodiment has, as media, a first disk 3A having a BPI that guarantees a stable operation in an operation guarantee temperature range as shown in FIGS. 4 and 5, and a stable operation in a low-temperature environment. And a second disk 3B having a BPI. In FIG. 4, reference numerals 41A and 41B denote individual sectors on the first disk 3A and the second disk 3B, respectively. When the lengths of these sectors in the circumferential direction are L1 and L2, the reciprocals of L1 and The ratio to the reciprocal of L2 corresponds to the ratio between the BPI of the first disk 3A and the BPI of the second disk 3B.
[0034]
However, the example in the figure schematically shows that the BPI relationship between the first disk 3A and the second disk 3B is (first disk 3A <second disk 3B). In practice, however, generally, a recording method such as a CDR (Constant Density Recording) method in which the BPI on the inner circumference and the BPI on the outer circumference are approximately equal on average is generally adopted.
[0035]
Next, a control method based on the environmental temperature in the hard disk drive 1 will be described.
[0036]
The temperature sensor 28 monitors the temperature t in the hard disk drive 1. The CPU 25 takes in the temperature information of the temperature sensor 28 and performs the following control based on the temperature information.
[0037]
Two low temperature guarantee limit temperatures T1 and T2 (T1> T2) are prepared in advance in a flash EEPROM or the like. Here, T1 is a low-temperature guaranteed limit temperature (for example, 5 ° C.) of the first disk 3A having a BPI that guarantees stable operation in an operation-guaranteed temperature range (first operation-guaranteed temperature range), and T2 is a low-temperature environment (second temperature). This is the low temperature guaranteed limit temperature (for example, -20 ° C.) of the second disk 3B having the BPI that guarantees stable operation in the operation guaranteed temperature range).
[0038]
(1) It is determined whether the temperature t is equal to or higher than T1.
[0039]
(2) If the temperature t is equal to or higher than T1, information is preferentially recorded on the first disk 3A. That is, recording at a high BPI is performed. However, when the first disk 3A runs out of free space, information is recorded on the second disk 3B.
[0040]
(3) If the temperature t is lower than T1, it is determined whether the temperature t is lower than T1 and higher than T2.
[0041]
{Circle around (4)} When the temperature t is lower than T1 and higher than T2, first, information is recorded on the second disk 3B. That is, recording is performed at a low BPI.
[0042]
(5) After information is recorded on the second disk 3B, the temperature t gradually rises while the hard disk drive 1 is operating.
[0043]
(6) It is determined whether or not the temperature t has become equal to or higher than T1.
[0044]
{Circle around (7)} After the temperature t has risen to T1 or more, the information recorded on the second disk 3B is read using the idle time of the hard disk drive 1, that is, the period during which no external access request is issued. Move to the first disk 3A.
[0045]
It is also conceivable that the temperature t is lower than T2.
[0046]
{Circle around (8)} In this case, the execution of reading / writing from / to each of the disks 3A and 3B is prohibited, and power is supplied to each unit, the spindle motor (SPM) 4 is driven, and the head is positioned on a predetermined track (for example, in the system area). Then, the internal temperature of the hard disk drive 1 is increased by performing a dummy write or the like for supplying a write current to the head. Then, after the temperature becomes higher than T2, the information recording on the second disk 3B of (4) is performed.
[0047]
By performing such control, the low temperature guaranteed limit temperature of the hard disk drive 1 is extended from T1 of the first disk 3A having a high BPI to T2 of the second disk 3B having a low BPI. Further, based on the overall storage capacity when only the first disk 3A having a high BPI is used, the decrease in the overall capacity due to the use of the second disk 3B having a low BPI is the second storage capacity having a low BPI. Less than when only the disc 3B is used.
[0048]
Therefore, in the case where the hard disk drive 1 is frequently used in a low-temperature environment, the hard disk drive 1 that is effective in terms of availability, reliability, and the like is realized even if the storage capacity is reduced due to the second disk 3B having a low BPI. can do.
[0049]
In the above embodiment, the case where two discs having different BPIs are used has been described. However, the present invention can be applied to a single disc.
[0050]
For example, as shown in FIG. 6, as the BPI of one signal recording surface 31 of one disk 3, a BPI that guarantees a stable operation in an operation guarantee temperature range (first operation guarantee temperature range) is set, and the other BPI is set. May be set as the BPI of the signal recording surface 32 for ensuring stable operation in a low-temperature environment (second operation guaranteed temperature range), and the same operation as in the above embodiment may be performed.
[0051]
Further, of the plurality of disks, only the BPI of one of the signal recording surfaces of any one of the disks is set to the BPI that ensures stable operation in a low temperature environment, and the BPI of the other signal recording surface (including other disks) is set. The BPI may be set to a BPI that guarantees stable operation within the operation guarantee temperature range.
[0052]
As shown in FIG. 7, the inside of one or both signal recording surfaces of the disk 3 is divided into a plurality of areas 34 and 35, and the BPI of a part of the area 34 guarantees stable operation in a low temperature environment. BPI in other regions may be set to BPI that guarantees stable operation within the operation guarantee temperature range.
[0053]
As described above, by setting the BPI of only one surface of one disk or a partial area of the one surface to a BPI that guarantees stable operation in a low-temperature environment, the overall storage capacity of the hard disk drive 1 is reduced. The amount can be reduced as compared with the first embodiment.
[0054]
How much the BPI area for ensuring stable operation in a low-temperature environment is secured as the entire drive depends on the time when the hard disk drive 1 is operated, the temperature rises from T2 in the low BPI area to T1 in the high BPI area. And the data transfer rate, and determine the maximum recording capacity that can be recorded during the temperature range of T2 to T1.
[0055]
Note that the present invention is not limited to any of the above-described embodiments, and can be appropriately modified and implemented within the scope of the technical idea of the present invention.
[0056]
In the above embodiment, the present invention is applied to a hard disk drive. However, the present invention can also be applied to a disk device using a disk-shaped storage medium other than a hard disk.
[0057]
【The invention's effect】
As described above, according to the present invention, the low-temperature guarantee limit temperature of the disk device can be lowered to a temperature lower than the normal operation guarantee temperature range, and stable operation in a low-temperature environment can be ensured.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a configuration of a hard disk drive which is an embodiment to which a disk device of the present invention is applied.
FIG. 2 is a block diagram showing a system configuration of the hard disk drive of FIG.
FIG. 3 is a graph showing a correlation among an ambient temperature, a BPI, and a BER in a hard disk drive.
FIG. 4 is a flowchart illustrating an example of a sector structure of each disk having a different BPI and a control procedure according to an environmental temperature.
FIG. 5 is a side view showing a part of the configuration of a hard disk drive using disks having different BPIs in FIG. 4;
FIG. 6 is a side view showing an example in which areas having different BPIs are provided on each of the front and back recording surfaces of the disc.
FIG. 7 is a diagram showing an example in which divided areas having different BPIs are provided on one surface of a disk.
[Explanation of symbols]
1 ... Hard disk drives 3A, 3B ... Disks with different BPIs 28 ... Temperature sensors 25 ... CPU
26 Memory 29 Heads 41A and 41B Sectors T1 and T2 Guaranteed low temperature limit

Claims (7)

A first recording area having a BPI (linear recording density) adapted to a first operation guaranteed temperature range, and a BPI adapted to a second operation guaranteed temperature range whose center temperature is lower than the first operation guaranteed temperature range. A disk-shaped storage medium having a second recording area,
Reading and writing means for reading and writing signals to and from the storage medium;
A temperature detecting unit for detecting a temperature,
When the temperature detected by the temperature detection unit is equal to or higher than the lowest temperature in the first operation guarantee temperature range, the first recording area is preferentially written by the read / write unit, and the detected temperature is the Control means for controlling the writing and reading means to write to the second recording area when the temperature is lower than the lowest temperature in the first operation guarantee temperature range and equal to or higher than the lowest temperature in the second operation guarantee temperature range. A disk device, comprising: The control means, when writing to the second recording area by the read / write means, after the detected temperature has become higher than or equal to the minimum temperature of the first operation assurance temperature range, 2. The disk device according to claim 1, wherein control is performed to move recording information from a recording area to the first recording area. The disk device according to claim 1, wherein the first recording area and the second recording area are set for each disk. 3. The disk device according to claim 1, wherein the first recording area and the second recording area are set in units of a signal recording surface of the disk. 3. The disk device according to claim 1, wherein the first recording area and the second recording area are respectively set in one signal recording surface of the disk. The disk-shaped storage medium is adapted to a first recording area having a BPI adapted to the first operation guaranteed temperature range, and to a second operation guaranteed temperature range whose center temperature is lower than the first operation guaranteed temperature range. A second recording area having a BPI is provided,
When the environmental temperature is equal to or higher than the lowest temperature of the first operation assurance temperature range, the first recording area is preferentially written by the read / write means,
When the environmental temperature is lower than the lowest temperature in the first operation guarantee temperature range and equal to or higher than the lowest temperature in the second operation guarantee temperature range, writing is performed in the second recording area by the read / write unit. A control method based on the environmental temperature of the disk device. When writing is performed in the second recording area, after the environmental temperature has risen to the minimum temperature of the first operation guarantee temperature range or higher, recording information is transferred from the second recording area to the first recording area. 7. The control method according to claim 6, wherein the disk drive is moved.

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