JP5805999B2 - Magnetic recording apparatus, diagnostic method thereof, and computer-executable program - Google Patents

Description

  The present invention relates to a magnetic recording apparatus, a diagnostic method thereof, and a computer-executable program.

  In a hard disk drive (HDD), the distance between the slider and the disk is called the fly height and is an important performance parameter. By reducing the distance between the recording / reproducing element and the disk during read and write operations, the bit error rate can be reduced, and accurate storage of data written at high linear density on the disk and Removal is possible.

  DFH (dynamic fly height) control, which embeds a heater coil around the recording / reproducing element mounted on the slider and drives the heater to thermally expand the slider to correct the distance between the recording / reproducing element and the disk, is a recent hard disk Commonly used in devices.

  The slider on which the recording / reproducing element is mounted floats on the disk at a height of about 10 nm. However, the flying height of the slider changes because the dimensional change of the mechanical components, the air molecule density, and the like change due to the change in the environmental temperature of the hard disk device. In general, the flying altitude of the slider is low in a high temperature environment, and the signal noise characteristics of the recorded data are improved by reducing the distance to the disk. On the other hand, the flying altitude of the slider is high and the distance from the disk is wide in a low temperature environment. As a result, the signal noise characteristics of the recorded data deteriorate.

  FIG. 9 is a diagram for explaining the relationship between the environmental temperature of the hard disk device and the flying height H of the slider. In the figure, the horizontal axis indicates the environmental temperature (° C.) of the hard disk device, the vertical axis indicates the flight altitude H (nm) of the slider, 100 indicates the design value characteristic line, and “●” indicates the actual measurement value. An example is shown. Since the relationship between the environmental temperature of the hard disk device and the flight altitude H of the slider varies among the hard disk devices, the flight altitude may be lower than the design value 100 as shown in FIG. As described above, the lower the flight altitude, the better the error rate for reading from the disk, so it will not be recognized as a read error, but if it continues to be used, the slider and disk will collide and a failure will occur. There is a case.

JP-A-5-20635 Japanese Patent No. 4255869 JP 2007-310978 A

  The present invention has been made in view of the above, and a magnetic recording apparatus capable of preventing a slider and a recording medium from colliding with each other due to a decrease in flying altitude of the slider, a diagnostic method thereof, and a computer are provided. The object is to provide an executable program.

  In order to solve the above-described problems and achieve the object, the present invention includes a slider mounted on the front end side of a suspension, a recording / reproducing element mounted on the slider, and a heater provided around the recording / reproducing element. A magnetic recording apparatus that controls the distance between the recording medium and the recording / reproducing element by heating the heater to cause the recording / reproducing element to protrude from the slider. Flight altitude measuring means for measuring the flight altitude of the slider by detecting contact with the recording medium by heating and causing the recording / reproducing element to protrude from the slider, and the slider measured by the flight altitude measuring means Determining means for determining whether or not the flying altitude of the slider is within a predetermined range, and when the determining means determines that the flying altitude of the slider is not within the predetermined range Characterized in that and a retracting means for retracting from said recording medium said head.

  According to a preferred aspect of the present invention, the flight altitude measuring means includes a table associating a heater power applied to the heater and a moving amount of the recording / reproducing element, and the contact is made with reference to the table. It is desirable to calculate the moving amount of the recording / reproducing element corresponding to the heater power at the time of detection, and to measure the flying altitude of the slider based on the calculated moving amount of the recording / reproducing element.

  According to a preferred aspect of the present invention, it is desirable that the flight altitude measuring means measures the flight altitude of the slider when the magnetic recording device is powered on.

  Further, according to a preferred aspect of the present invention, the flight altitude measuring means is configured such that when the temperature in the magnetic recording apparatus has increased by a predetermined amount, or when the atmospheric pressure in the magnetic recording apparatus has decreased by a predetermined amount, It is desirable to measure the flight altitude of the slider.

  Further, according to a preferred aspect of the present invention, the flight altitude measuring means decreases the temperature in the magnetic recording apparatus by a predetermined amount when the determining means determines that the flight altitude of the slider is not within a predetermined range. It is desirable to measure the flying altitude of the slider when the atmospheric pressure in the magnetic recording apparatus increases by a predetermined amount.

  According to a preferred aspect of the present invention, when the determination means determines that the flight altitude of the slider is not within a predetermined range, an error is sent to the host device when a command is received from the host device. It is desirable to reply.

  Further, according to a preferred aspect of the present invention, when the determination means determines that the flight altitude of the slider is not within a predetermined range, the flight altitude measured with the temperature or the atmospheric pressure in the magnetic recording device. It is desirable to provide recording means for recording error information including

  In order to solve the above-described problems and achieve the object, the present invention provides a slider mounted on the front end side of a suspension, a recording / reproducing element mounted on the slider, and provided around the recording / reproducing element. A head mounted with a heater, and a magnetic recording apparatus that controls the distance between the recording medium and the recording / reproducing element by causing the recording / reproducing element to protrude from the slider by heating the heater. In the method, a flight altitude measuring step of measuring the flight altitude of the slider by detecting the contact with the recording medium by heating the heater to project the recording / reproducing element from the slider, and measuring the flight altitude A determination step for determining whether the flying altitude of the slider measured in the step is within a predetermined range; and the flying altitude of the slider in the determination step is not within a predetermined range. If it is determined that, characterized in that it comprises a and a retracting step for retracting the slider.

  In order to solve the above-described problems and achieve the object, the present invention provides a slider mounted on the front end side of a suspension, a recording / reproducing element mounted on the slider, and provided around the recording / reproducing element. Mounted on a magnetic recording apparatus that controls the distance between the recording medium and the recording / reproducing element by causing the recording / reproducing element to protrude from the slider by heating the heater. A flight altitude measuring step of measuring the flight altitude of the slider by detecting the contact with the recording medium by heating the heater and projecting the recording / reproducing element from the slider; A determination step of determining whether or not the flying altitude of the slider measured in the altitude measurement step is within a predetermined range; and the flying altitude of the slider in the determination step If it is determined not to be within the constant range, characterized in that to execute a retracting step for retracting the slider, to the computer.

  According to the present invention, there is an effect that it is possible to provide a magnetic recording apparatus capable of preventing the flying altitude of the slider from being lowered and the slider and the recording medium from colliding with each other.

FIG. 1 is a plan view showing a schematic structure in a housing of a hard disk device to which the magnetic recording device according to the present embodiment is applied. FIG. 2 is a diagram illustrating a schematic hardware configuration example of the hard disk device of FIG. FIG. 3 is a schematic side view showing the main part of the slider. FIG. 4 is a schematic front view showing the tip of the slider. FIG. 5 is a diagram illustrating an example of the relationship between the heater power (mW) of the heater and the amount of movement of the recording / reproducing element in the X direction. FIG. 6 is a flowchart for explaining slider flight altitude diagnosis processing executed by the control unit. FIG. 7 is a diagram illustrating a schematic hardware configuration example of the hard disk device according to the second embodiment. FIG. 8 is a flowchart for explaining slider flight altitude diagnosis processing according to the second embodiment. FIG. 9 is a diagram for explaining the relationship between the environmental temperature of the hard disk device and the flying height H of the slider.

  Exemplary embodiments of a magnetic recording apparatus, a diagnosis method therefor, and a program executable by a computer will be described below in detail with reference to the accompanying drawings. In the following embodiments, a case where the magnetic recording device according to the present invention is applied to a hard disk device will be described. The present invention is not limited to the following embodiment. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or that are substantially the same.

(Embodiment 1)
FIG. 1 is a schematic plan view showing a schematic structure in a housing of a hard disk device to which the magnetic recording device according to the present embodiment is applied. The hard disk device 1 shown in FIG. 1 uses a load / unload method of the head 13. The hard disk device 1 includes an SPM (Spindle Motor) 12, a rotatable disk (magnetic disk) 11, a slider 19 that can float with respect to the surface of the disk 11, and a slider 19 mounted on the tip of the hard disk device 1. A possible suspension 10, a head 13 mounted on the foremost portion of the slider 19, a recording / reproducing element 14 mounted on the head 13, and a VCM (Voice Coil Motor) that drives the suspension 10 via an arm (not shown). 15 and a lamp (retraction area) 16.

  A large number of concentric tracks (not shown) are formed on each surface (recording surface) of the disk 11, and each track has a servo area in which servo data used for seek and positioning of the head is recorded. Arranged at intervals. Between the servo areas is a user area, and a plurality of sectors as recording units are arranged in the user area. In the present embodiment, one disk 11 is arranged, but a configuration in which a plurality of disks are stacked and arranged may be used.

  The slider 19 is attached to a leaf spring-like load beam (not shown) of the suspension 10 on the recording surface side of the disk 11 at the tip of the suspension 10 (see FIG. 2). A head 13 is mounted on the most distal portion of the slider 19 (see FIG. 2). The head 13 is provided with a recording / reproducing element 14 used for reading data from the disk 11 (data reproduction) and writing data to the disk 11 (data recording). The recording / reproducing element 14 moves in the radial direction of the disk 11 according to the angular rotation of the head 13. As a result, the recording / reproducing element 14 is sought and positioned on the target track.

  On the outer peripheral side of the disk 11, a lamp 16 is disposed to retract the head 13 when the rotation of the disk 11 is stopped. Further, in the slider flight altitude diagnosis process described later, when the flight altitude H of the slider 19 is not within a predetermined range, the head 13 is unloaded (retracted) from the disk 11 to the ramp 16.

  The SPM 12 is a motor that rotates the disk 11 at a high speed. The VCM 15 is a motor for moving the head 13, which is a support mechanism for the recording / reproducing element 14, in the radial direction of the disk 11.

  FIG. 2 is a diagram illustrating a schematic hardware configuration example of the hard disk device of FIG. In FIG. 2, the slider 19 and the head 13 are shown enlarged. As shown in FIG. 2, the hard disk device 1 includes a disk 11, an SPM 12, a suspension 10, a slider 19, a head 13, a recording / reproducing element 14, a heater 17, a control unit 20, and a drive control unit 30. A read / write signal processing unit 31, a data memory 32, a heater driving unit 33, a temperature detection unit 34, and a hard disk controller 35.

  The disk 11 is a disk as a magnetic recording medium, and records various data input from the outside. Also, in the SMART area of the disk 11, SMART (Self-Monitoring, Analysis and Reporting Technology) information (temperature, data read / write error rate, number of defective sectors, seek error rate, power ON / OFF count) is controlled by the control unit 20. Etc.) is written.

  The head 13 includes a recording / reproducing element (for example, a GMR element) 14 for reading / writing data from / to the disk 11, a thermal expansion member (not shown: see FIGS. 3 and 4), and a recording / reproducing element. 14, and a heater 17 that moves the recording / reproducing element 14 by heating and thermally expanding the thermal expansion member. The heater 17 controls the amount of heat generated by the heater driving unit 33.

  The drive control unit 30 includes drive circuits that drive the SPM 12 and the VCM 15 according to the control of the control unit 20, and performs drive control of the SPM 12 and the VCM 15.

  The temperature detection unit 34 can be configured by, for example, a thermistor, and detects the temperature in the housing of the hard disk device 1 and outputs it to the control unit 20. The heater drive unit 33 includes a drive circuit that drives the heater 17 provided in the head 13, and performs drive control of the heater 17 according to the control of the control unit 20.

  The read / write signal processing unit 31 outputs position information and sector data recorded in the servo area of the disk 11 under the control of the control unit 20. Further, the read / write signal processing unit 31 performs encoding of data to be written to the disk 11 and decoding of data read from the disk 11 according to control of the control unit 20, and encoding and error detection using an error correction code at that time In addition, processing related to error correction is also performed.

  The data memory 32 buffers data read from the disk 11 and data to be written to the disk 11. The hard disk controller 35 constitutes an input / output circuit for data, control commands, and the like transmitted / received to / from a host device 50 such as a personal computer or AV device via an interface. Here, the interface is IDE (Integrated Drive Electronics), SCSI (Small Computer System Interface), FC (Fiber Channel), USB (Universal Serial Bus), SATA (Serial ATA), or the like.

  The control unit 20 controls the entire operation of the hard disk device 1. The CPU 21 controls the operation of the hard disk device 1 according to the firmware stored in the ROM 22. The ROM 22 stores the firmware executed by the CPU 21. The CPU 21 serves as a work area. A RAM 23 to be used, a heater power-recording / reproducing element movement amount table 24a (see FIG. 5), and the like are configured. The controller 20 performs DHF (dynamic fly height) control for correcting the distance between the recording / reproducing element 14 and the disk 11 by driving the heater 17 to thermally expand the thermal expansion member of the head 13. Moreover, the control part 20 performs the slider flight altitude diagnostic process mentioned later.

  An outline of the servo operation of the hard disk device 1 configured as shown in FIGS. 1 and 2 will be described. In the hard disk device 1, the position information is read from the servo area of the disk 11 by the recording / reproducing element 14 and is output to the control unit 20 via the read / write signal processing unit 31. Based on this position information, the control unit 20 drives the VCM 15 and SPM 12 via the drive control unit 30 to move the recording / reproducing element 14 to a predetermined position. Then, a data write or read operation is performed on the data area of the disk 11.

  Next, an outline of data read / write operations of the hard disk device 1 will be described. When the hard disk controller 35 receives a command (such as a write / read command) issued from the host device 50 via the interface, the hard disk controller 35 interprets the contents of the command and notifies the control unit 20 of the interpretation. The control unit 20 sets necessary commands and parameters for the drive control unit 30 and the read / write signal processing unit 31 based on the notification contents, and causes those operations to be executed.

  The drive control unit 30 performs drive control of the SPM 12 and the VCM 15 to move the head 13 (recording / reproducing element 14) with respect to a predetermined track and sector of the disk 11. The read / write signal processing unit 31 encodes (modulates) the transmitted data into a digital bit sequence when writing to the disk 11. Further, at the time of reading, the read / write signal processing unit 31 removes high frequency noise from the signal read from the recording / reproducing element 14 and then performs conversion from an analog signal to a digital signal, and further, ECC (Error Correction Code) Perform error correction. Here, the ECC error correction is performed at different levels depending on the degree of error in the read signal.

  In order to stop the rotation of the SPM 12, the head 13 is moved in the radial direction of the disk 11 as shown by the arrow S in FIG. 1, and the recording / reproducing element 14 is unloaded from the disk 11 onto the ramp 16. This prevents the slider 19 and the disk 11 from contacting each other.

  FIG. 3 is a side view showing the main parts of the slider 19 and the head 13, and FIG. 4 is a front view showing the tip parts of the slider 19 and the head 13. The head 13 is levitated by the wedge film effect of air applied to the slider 19 so that the disk 11 and the slider 19 are not in direct contact with each other. In this embodiment, in order to increase the recording density of the disk 11 and to increase the capacity or size of the apparatus, the distance between the slider 19 and the disk 11, that is, the slider flight altitude H is shortened, and the linear recording density is reduced. It is considered to raise.

  3 and 4, the slider 19 has a substantially U-shaped section at the tip, and the recording / reproduction of the head 13 is performed between the first surface 19 a and the second surface 19 b of the slider 19 facing the disk 11. Element 14 is arranged. The first surface 19a and the second surface 19b protrude beyond the surface 14a of the recording / reproducing element 14 facing the disk 11 when the heater 17 is not heated. Between the heater 17 and the recording / reproducing element 14, for example, a thermal expansion member 18 composed of a thin film resistor is disposed. The heating amount of the heater 17 is controlled by the heater power applied by the heater driving unit 33, and the thermal expansion member 18 is thermally expanded in the arrow X direction according to the heating amount. Since the heater current, the heater voltage, or both the heater current and the heater voltage may be controlled, the heater power is controlled here.

  The recording / reproducing element 14 moves in the direction of the arrow X in accordance with the thermal expansion of the thermal expansion member 18 and protrudes from the slider 19 (projects from the first surface 19a and the second surface 19b). Since the structure in which the heater 17 is heated to project the recording / reproducing element 14 is known, a detailed description thereof will be omitted. Note that the structure for projecting the recording / reproducing element 14 is not limited to the example shown in FIGS. 3 and 4, and various structures can be adopted.

  3 and 4, H is the flight altitude of the slider 19 with respect to the disk 11, and R is the state when the heater 17 is not heated (the expansion amount of the thermal expansion member 18 is “0”). 1 is a distance (a constant value) between the surface 19a and the surface 14a of the recording / reproducing element 14, E is the amount of movement of the recording / reproducing element 14 in the X direction, and L is the distance between the recording / reproducing element 14 and the disk 11. Yes. Since the recording / reproducing element 14 moves in the X direction as the thermal expansion member 18 expands in the X direction, the movement amount E in the X direction of the recording / reproducing element 14 increases the expansion of the thermal expansion member 18 in the X direction. It is the same as the amount.

  FIG. 5 is a diagram showing an example of the relationship between the heater power (mW) of the heater 17 and the movement amount E in the X direction of the recording / reproducing element 14. In the figure, the horizontal axis represents the heater power (mW) of the heater 17, and the vertical axis represents the movement amount E of the recording / reproducing element 14 in the X direction. The heater power (mW) of the heater 17 and the amount of movement E in the X direction of the recording / reproducing element 14 have a relationship as shown in FIG. 5, and the amount of movement of the recording / reproducing element 14 in the X direction is controlled by controlling the heater power. E can be controlled. In the heater power-recording / reproducing element movement amount table 24a of FIG. 2, the relationship shown in FIG. 5 is registered as data.

  As described above, the flight altitude H of the slider 19 is a value set in the design / manufacturing stage. However, since it changes due to individual differences in the device, environmental temperature, atmospheric pressure, aging, etc. There is a case. If the flying height H of the slider 19 is lower than the expected range, the slider 19 and the disk 11 may collide. Therefore, in the present embodiment, the control unit 20 executes the slider flight altitude diagnosis process, and when the flight altitude H of the slider 19 is not within the predetermined range, the control unit 20 retracts the head 13 from the disk 11 to the ramp 16. Thus, the collision between the slider 19 and the disk 11 is prevented. The slider flight altitude diagnosis processing is periodically executed, for example, when the power is turned on, and is further executed when the environment (high temperature, low pressure) becomes low after the power is turned on. .

  Next, a method for measuring the flying height H of the slider 19 will be described. The control unit 20 seeks the head 13 to the flight altitude measurement target track while the disk 11 is rotating, gradually increases the heater power applied to the heater 17, and touches the recording / reproducing element 14 against the disk 11. Bring down (contact).

  The flight altitude measurement target track may be the entire area of the inner circumference (ID), middle circumference (MD), and outer circumference (OD) of the disk 11, but all the inner circumference, middle circumference, and outer circumference of the disk 11 at the time of manufacture. The flight altitude H may be measured for the area, and only the area where the flight altitude is the lowest may be measured. Also, when measuring the flight altitude for the first time after product shipment, the entire area of the inner circumference, middle circumference, and outer circumference of the disk 11 will be measured. It may be.

  The control unit 20 detects the touchdown, refers to the heater power-recording / reproducing element movement amount table 24a, and calculates the movement amount E in the X direction of the recording / reproducing element 14 from the heater power when the touchdown is performed. Then, the control unit 20 calculates the flight altitude H based on the movement amount E in the X direction of the recording / reproducing element 14 and the distance R (flight altitude H = movement amount E of the recording / reproducing element 14 in the X direction E−distance R). ). In addition, the detection of touchdown can use various well-known methods, for example, the method (for example, refer patent document 3) which detects thermal asperity can be used.

  FIG. 6 is a flowchart for explaining the slider flight altitude diagnosis process executed by the control unit 20. In FIG. 6, when the power is turned on (step S1), the control unit 20 captures the detection result of the temperature detection unit 34 and measures the temperature (step S2). Next, the control unit 20 seeks the head 13 to the flight altitude measurement target track (step S3), and measures the flight altitude H (step S4). The control unit 20 determines whether or not the measured flight altitude H is within a predetermined range (step S5). Specifically, the control part 20 can be set within a predetermined range when the measured flight altitude H ≧ threshold N1.

When the measured flight altitude H is within the predetermined range (“Yes” in step S5), the control unit 20 periodically measures the temperature (step S6), and whether or not ΔT has risen from the previous temperature measurement value. Is determined (step S7). If ΔT has not risen from the previous temperature measurement value (“No” in step S7), the process returns to step S6. When ΔT is increased from the previous temperature measurement value (“Yes” in step S7), the control unit 20 determines whether or not the idle state is set (step S8). If it is not in the idle state (“No” in step S8), it waits until it is in the idle state. If it is in an idle state (“Yes” in step S8),
Returning to step S3, the control unit 20 measures the flight altitude H of the flight altitude measurement target track, and determines whether or not the measured flight altitude H is within a predetermined range (steps S3 to S5).

  On the other hand, when the measured flight altitude H is not within the predetermined range (“No” in step S5), the control unit 20 records the measured temperature and the flight altitude H as error information in the SMART area of the disk 11 ( Step S9), the head 13 is unloaded onto the lamp 40 (Step S10).

  Thereafter, the control unit 20 periodically measures the temperature (step S11), and determines whether or not ΔT has decreased from the previous temperature measurement value (step S12). When ΔT has fallen from the previous temperature measurement value (“Yes” in step S12), the process returns to step S3, and the control unit 20 measures the flight altitude H of the flight altitude measurement target track. It is determined whether it is within a predetermined range (steps S3 to S5).

  On the other hand, when ΔT has not fallen from the previous temperature measurement value (“No” in step S12), the control unit 20 determines whether an access command has been received from the host device 50 (step S13). If the access command has not been received from the host device 50 (“No” in step S13), the process returns to step S11. If the access command has been received from the host device 50 (“Yes” in step S13). The controller 20 returns an error to the host device 50 (step S14), and then returns to step S11.

  As described above, according to the first embodiment, the control unit 20 causes the recording / reproducing element 14 to protrude from the slider 19 by heating the heater 17, thereby touching down the disk 11 and detecting the touchdown. Then, the flying altitude H of the slider 19 is measured, it is determined whether or not the measured flying altitude H of the slider 19 is within a predetermined range, and it is determined that the measured flying altitude H of the slider 19 is not within the predetermined range. In this case, since the head 13 is unloaded, it is possible to prevent the slider and the recording medium from colliding with each other even when the flying altitude of the slider is lowered due to temperature rise or deterioration with time. .

  Further, the control unit 20 includes a heater power-recording / reproducing element movement amount table 24a in which the heater power applied to the heater 17 and the movement amount E of the recording / reproducing element 14 are associated with each other. Referring to 24a, the moving amount E of the recording / reproducing element 14 corresponding to the heater power when the contact is detected is calculated, and the flight altitude is measured based on the calculated moving amount E of the recording / reproducing element. Therefore, the flight altitude H can be measured by a simple method.

  Further, since the control unit 20 measures the flight altitude H of the slider 19 when the hard disk device 20 is turned on, the flight altitude can be measured periodically.

  Further, since the control unit 20 measures the flight altitude H of the slider 19 when the temperature in the hard disk device 1 rises by a predetermined amount, the control unit 20 can perform the measurement under the condition that the flight altitude H is low. .

  Further, when it is determined that the flying altitude of the slider 19 is not within the predetermined range, the control unit 20 further measures the flying altitude H of the slider 19 when the temperature in the hard disk device 1 is lowered by a predetermined amount. Therefore, when the measurement is performed under the condition that the flight altitude H is high, the flight altitude of the slider 19 may be within a predetermined range, so that the hard disk device can be used as much as possible.

  In addition, when the control unit 20 determines that the flight altitude H of the slider 19 is not within the predetermined range, when it receives a command from the host device 50, it returns an error. It is possible to notify that the device 1 cannot be used.

  If the control unit 20 determines that the flight altitude H of the slider 19 is not within the predetermined range, the controller 20 records the temperature in the hard disk device 1 and the measured flight altitude as SMART information. By analyzing the information, it becomes possible to elucidate the cause of the failure.

(Embodiment 2)
A hard disk device according to the second embodiment will be described with reference to FIGS. FIG. 7 is a diagram illustrating a schematic hardware configuration example of the hard disk device according to the second embodiment. 7, parts having the same functions as those in FIG. 2 are denoted by the same reference numerals, description of common parts is omitted, and only different points will be described. As shown in FIG. 7, the second embodiment has a configuration in which an atmospheric pressure detection unit 38 is provided instead of the temperature detection unit 34 of FIG. The atmospheric pressure detection unit 38 detects the atmospheric pressure in the housing of the hard disk device 1 and outputs it to the control unit 20.

  FIG. 8 is a flowchart for explaining slider flight altitude diagnosis processing according to the second embodiment. In FIG. 8, steps that perform the same processing as in FIG. 6 are given the same step numbers. When the power is turned on (step S1), the control unit 20 takes in the detection result of the atmospheric pressure detection unit 38 and measures the atmospheric pressure (step S21). Next, the control unit 20 seeks the head 13 to the flight altitude measurement target track (step S3), and measures the flight altitude H (step S4). The control unit 20 determines whether or not the measured flight altitude H is within a predetermined range (step S5).

  When the measured flight altitude H is within the predetermined range (“Yes” in step S5), the control unit 20 periodically measures the atmospheric pressure (step S22), and whether or not ΔP has decreased from the previous atmospheric pressure measurement value. Is determined (step S23). If ΔP has not fallen from the previous atmospheric pressure measurement value (“No” in step S23), the process returns to step 22. When ΔP has fallen from the previous atmospheric pressure measurement value (“Yes” in step S23), the control unit 20 determines whether or not it is in an idle state (step S8). If it is not in the idle state (“No” in step S8), it waits until it is in the idle state. If it is in the idle state (“Yes” in step S8), the process returns to step S3, and the control unit 20 measures the flight altitude H of the flight altitude measurement target track, and whether or not the measured flight altitude H is within the specification range. Is determined (steps S3 to S5).

  On the other hand, when the measured flight altitude H is not within the predetermined range (“No” in step S5), the control unit 20 records the measured atmospheric pressure and the flight altitude H as error information in the SMART area of the disk 11 ( Step S9), the head 13 is unloaded to the lamp 16 (Step S10).

  Thereafter, the control unit 20 periodically measures the atmospheric pressure (step S24), and determines whether or not ΔP has increased from the previous atmospheric pressure measurement value (step S25). When ΔP has increased from the previous atmospheric pressure measurement value (“Yes” in step S25), the process returns to step S3, and the control unit 20 measures the flight altitude H of the flight altitude measurement target track. It is determined whether it is within a predetermined range (steps S3 to S5).

  On the other hand, when ΔP has not increased from the previous atmospheric pressure measurement value (“No” in step S25), the control unit 20 determines whether an access command has been received from the host device 50 (step S13). If the access command has not been received from the host device 50 (“No” in step S13), the process returns to step S11. If the access command has been received from the host device 50 (“Yes” in step S13). The controller 20 returns an error to the host device 50 (step S14), and then returns to step S11.

  According to the second embodiment, it is possible to prevent the slider and the recording medium from colliding with each other even if the flying altitude of the slider is decreased due to a decrease in atmospheric pressure or deterioration with time.

  The first embodiment and the second embodiment may be implemented singly or in combination. The first and second embodiments of the apparatus, method, and program of the present invention do not limit the scope of the present invention shown in the claims, but are merely examples of selected embodiments of the present invention. It is intended to merely illustrate selected embodiments of apparatus and methods consistent with the present invention as set forth in the claims. One skilled in the art can implement the present invention without one or more of the specific details or with other methods, components, modules, materials. Further, those skilled in the art can change the order of steps in the processing shown in the flowchart, delete steps, and add new steps.

  The magnetic recording apparatus according to the present invention, its diagnostic method, and computer-executable program are widely applicable to magnetic recording apparatuses, and are particularly suitable for magnetic recording apparatuses that perform high-density recording.

DESCRIPTION OF SYMBOLS 1 Hard disk apparatus 10 Suspension 11 Disk 12 SPM (Spindle Motor)
13 Head 14 Recording / Reproducing Element 15 VCM (Voice Coil Motor)
16 lamps
17 Heater 18 Thermal Expansion Member 19 Slider 20 Control Unit 21 CPU
22 ROM
23 RAM
24 Non-volatile memory 24a Heater power-recording / reproducing element movement amount table 30 Drive control unit 31 Read / write signal processing unit 32 Data memory 33 Heater drive unit 34 Temperature detection unit 35 Hard disk controller 38 Atmospheric pressure detection unit 50 Host device

Claims (8)

A slider mounted on the front end side of the suspension; and a head mounted on the slider and mounted with a recording / reproducing element and a heater provided around the recording / reproducing element; and heating the heater In the magnetic recording apparatus for controlling the interval between the recording medium and the recording / reproducing element by projecting the recording / reproducing element from the slider,
The recording / reproducing element is in a state where it does not protrude from the surface of the slider facing the recording medium when the heater is not heated,
Data relating the heater power applied to the heater and the amount of movement of the recording / reproducing element is stored, and the heater is heated to cause the recording / reproducing element to protrude from the surface of the slider facing the recording medium. Then, the contact with the recording medium is detected, the movement amount of the recording / reproducing element corresponding to the heater power when the contact is detected is calculated with reference to the data, and the calculated movement of the recording / reproducing element is calculated. The flying altitude of the slider from the recording medium is measured based on the amount and the distance between the surface of the slider facing the recording medium and the recording / reproducing element when the heater is not heated. Flight altitude measuring means;
Determining means for determining whether or not the flight altitude of the slider measured by the flight altitude measuring means is within a predetermined range;
Retreating means for retreating the slider from the recording medium when the determination means determines that the flying altitude of the slider is not within a predetermined range;
A magnetic recording apparatus comprising:   The magnetic recording apparatus according to claim 1, wherein the flight altitude measuring unit measures a flight altitude of the slider when the magnetic recording apparatus is powered on.   The flight altitude measuring means measures the flight altitude of the slider when the temperature in the magnetic recording device increases by a predetermined amount or when the atmospheric pressure in the magnetic recording device decreases by a predetermined amount. The magnetic recording apparatus according to claim 1 or 2.   The flight altitude measuring means, when the judging means determines that the flight altitude of the slider is not within a predetermined range, when the temperature in the magnetic recording apparatus has dropped by a predetermined amount, or in the magnetic recording apparatus 4. The magnetic recording apparatus according to claim 1, wherein a flying altitude of the slider is measured when the atmospheric pressure increases by a predetermined amount. 5.   2. The apparatus according to claim 1, wherein when the determination unit determines that the flight altitude of the slider is not within a predetermined range, an error is returned to the host device when a command is received from the host device. The magnetic recording apparatus according to claim 1.   Further, when the determination means determines that the flight altitude of the slider is not within a predetermined range, recording means for recording error information including the temperature or atmospheric pressure in the magnetic recording device and the measured flight altitude is provided. 6. The magnetic recording apparatus according to claim 1, further comprising a magnetic recording apparatus. A slider mounted on the front end side of the suspension; and a head mounted on the slider and mounted with a recording / reproducing element and a heater provided around the recording / reproducing element; and heating the heater In a diagnostic method for a magnetic recording apparatus in which a recording / reproducing element is projected from the slider to control a distance between a recording medium and the recording / reproducing element.
The recording / reproducing element is in a state where it does not protrude from the surface of the slider facing the recording medium when the heater is not heated,
Data relating the heater power applied to the heater and the amount of movement of the recording / reproducing element is stored, and the heater is heated to cause the recording / reproducing element to protrude from the surface of the slider facing the recording medium. Then, the contact with the recording medium is detected, the movement amount of the recording / reproducing element corresponding to the heater power when the contact is detected is calculated with reference to the data, and the calculated movement of the recording / reproducing element is calculated. The flying altitude of the slider from the recording medium is measured based on the amount and the distance between the surface of the slider facing the recording medium and the recording / reproducing element when the heater is not heated. Flight altitude measurement process,
A determination step of determining whether or not the flight altitude of the slider measured in the flight altitude measurement step is within a predetermined range;
A retracting step of retracting the slider from the recording medium when it is determined in the determining step that the flight altitude of the slider is not within a predetermined range;
A method for diagnosing a magnetic recording apparatus, comprising: A slider mounted on the front end side of the suspension; and a head mounted on the slider and mounted with a recording / reproducing element and a heater provided around the recording / reproducing element; and heating the heater A program mounted on a magnetic recording device for controlling a distance between a recording medium and the recording / reproducing element by projecting the recording / reproducing element from a slider,
The recording / reproducing element is in a state where it does not protrude from the surface of the slider facing the recording medium when the heater is not heated,
Data relating the heater power applied to the heater and the amount of movement of the recording / reproducing element is stored, and the heater is heated to cause the recording / reproducing element to protrude from the surface of the slider facing the recording medium. Then, the contact with the recording medium is detected, the movement amount of the recording / reproducing element corresponding to the heater power when the contact is detected is calculated with reference to the data, and the calculated movement of the recording / reproducing element is calculated. The flying altitude of the slider from the recording medium is measured based on the amount and the distance between the surface of the slider facing the recording medium and the recording / reproducing element when the heater is not heated. Flight altitude measurement process,
A determination step of determining whether or not the flight altitude of the slider measured in the flight altitude measurement step is within a predetermined range;
A retracting step of retracting the slider from the recording medium when it is determined in the determining step that the flight altitude of the slider is not within a predetermined range;
A computer-executable program characterized by causing a computer to execute.

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