JP2893912B2 - Disk drive device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive, and more particularly to a disk drive of 3.5 inches or less.

[Summary of the Invention]

According to the present invention, in the disk drive device, the rotation speed of the spindle motor is set to R ≧ [(N + 2) / N] × 3600
(R is the number of revolutions (rpm) and N is the number of sectors per track), so that noise is generated in synchronization with the cycle of the power supply voltage, and this noise is superimposed on the power supply voltage. By performing one extra read or write operation, the sector can be read or written without fail, and the rotation waiting time can be prevented from deteriorating. Also, the specifications for the power supply, the system shield, the design conditions for the vicinity of the ground, etc. Therefore, the specifications relating to the noise can be relaxed and the cost can be reduced.

[Conventional technology]

The rotation speed of a spindle motor in a 3.5-inch or less disk drive device without a built-in controller, for example, a hard disk drive device, is limited by interface limitations when the frequency of the power supply voltage is 60 Hz.
It was often set at 3600 rpm or near it.

[Problems to be solved by the invention]

By the way, the above-mentioned spindle motor rotation speed 3600rpm
Has the same cycle as the commercial power supply voltage.

Therefore, when noise is generated in synchronization with the power supply voltage cycle and superimposed on the power supply voltage, data is read from the disk only for a specific sector corresponding to the noise generation cycle (hereinafter, referred to as a read operation). Alternatively, there has been a problem that operations such as writing data to a disk (hereinafter, referred to as a write operation) are obstructed.

FIG. 3A shows the waveform of the power supply voltage VAC and the noise NO, and FIG. 3B shows the sector format. If the frequency of the power supply voltage VAC is, for example, 60 Hz, one cycle thereof is (1/60) second. Noise NO1, N
Since O2 is generated in synchronization with the frequency of the power supply voltage VAC as described above, O2 is periodically superimposed on a fixed position of the waveform of the power supply voltage VAC as illustrated.

On the other hand, the rotation speed of the spindle motor is 3600 rpm, which is 60 rotations per second, so that the rotation cycle is (1/60) second. As a result, the rotation speed 3600 rpm has the same cycle as the frequency of the power supply voltage VAC.

Therefore, as shown in FIG. 3, the timings at which the noises NO1 and NO2 occur always correspond to the same sector SE2, and the read operation or the write operation to the sector SE2 cannot be performed due to the noises NO1 and NO2. There was a problem.

As a result, there is a problem that the read operation or the write operation cannot be performed as the rotational speed approaches 3600 rpm.

In such a case, usually, the read operation or the write operation is performed again. However, the sector corresponding to the timing at which the noises NO1 and NO2 occur is defined as the sector SE2 from the point of the cycle as described above. Also, the read operation or the write operation cannot be performed, and even if the read operation or the write operation is performed several times, the read operation or the write operation cannot be performed properly due to the influence of noise.

Therefore, in a system equipped with such a hard disk drive device, the specifications for the power supply, the shielding of the system, and the design conditions with respect to the vicinity of the earth are strict.

In particular, in the case of an external hard disk drive unit, there is a problem in that the specifications for the power supply are specified by the hard disk drive unit, which is costly.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a disk drive device capable of eliminating the influence of noise by changing a sector corresponding to a noise generation cycle.

[Means for solving the problem]

In the disk drive device according to the present invention, the rotation speed of the spindle motor is set to R ≧ [(N + 2) / N] × 3600
(R is the number of rotations (rpm), N is the number of sectors per track).

[Action]

The number of rotations of the spindle motor for rotating the disk-shaped recording medium is changed by at least two sectors per track at an early stage to change the sector corresponding to the noise generation cycle.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In this embodiment, a reproduction system of a hard disk drive device of 3.5 inches or less which incorporates control means such as a CPU or a controller and can freely set the number of revolutions of a spindle motor is described.

The rotation speed of the spindle motor is, for example, 3000 rpm when the frequency of the power supply voltage is 50 Hz and 3600 rpm when the frequency is 60 Hz.In this embodiment, the frequency of the power supply voltage is 60 Hz and the spindle motor is rotated. The case where the rotation speed is 3600 rpm and the frequency of the noise is 60 Hz is described.

In FIG. 1, a portion indicated by a dashed line is the hard disk drive device 1.

In the configuration shown in FIG. 1, an external host computer 2 is connected via an interface 3 to a controller 4, a CPU 5 and the like inside the hard disk drive 1, and various types of data supplied from the host computer 2 are provided. A start operation, a read operation, and the like are performed by the control signal.

At the time of startup, a start command signal for the spindle motor 8 is supplied from the host computer 2 to the CPU 5 via the interface 3.

The CPU 5 controls the entire hard disk drive 1 including the controller 4.
RAM6, ROM7, etc. are connected. Then, when the above-described start command signal is supplied to the CPU 5, the CPU 5 outputs the spindle motor 8, for example,
A control signal for starting the three-phase DC motor is formed, and the control signal is supplied to the controller 4.

Controller 4 is based on a control signal from CPU 5
Drive control of arm 9, spindle motor 8, etc., buffer
It controls writing of data to the RAM 11, reading of data from the buffer RAM 11, and the like. The controller 4 forms a drive signal for rotating the spindle motor 8 based on the control signal supplied from the CPU 5, and supplies the drive signal to the driver circuit 12.

The driver circuit 12 rotates the spindle motor 8 based on the drive signal supplied from the controller 4 to rotate the disk 10. This disk 10 is a CAV (Constant
Angular Velocity) method. An FG pulse is formed with the rotation of the spindle motor 8, and the FG pulse is supplied to the rotation speed detection circuit 13.

In the rotation speed detection circuit 13, the frequency is compared between the clock signal CLK supplied through the terminal 14 and the FG pulse, and a signal having a level corresponding to the frequency error is formed. A signal having a level corresponding to the frequency error is supplied to the rotation control circuit 15.

The comparison in the rotation speed detection circuit 13 is performed using, for example, a counter. That is, the period of the FG pulse is converted into the number of clock signals CLK counted during a period in which the FG pulse is at a high level, for example, and compared with a reference value.

For example, when the rotation speed is low and the frequency of the FG pulse is low, such as when starting, the counted clock signal CLK is used.
Number greatly exceeds the standard value. Also, the frequency of the FG pulse increases as the rotation speed increases, and the clock signal CL counted as the frequency of the FG pulse increases.
The number of K decreases and gradually approaches the reference value. When the number of clocks CLK to be counted is equal to the reference value, a high impedance state is set.

The difference between the number of clocks CLK to be counted and the reference value is defined as a frequency error, and a signal having a level corresponding to the frequency error is supplied to the rotation control circuit 15.

In the rotation control circuit 15, a drive signal having a level corresponding to the frequency error is formed and supplied to the driver circuit 12.

The driver circuit 12 performs servo control on the rotation speed of the spindle motor 8 based on the above-described drive signal.

As a result, the rotation speed detection circuit 13, the rotation control circuit 15, the driver circuit 12, and the spindle motor 8 constitute a servo system using FG pulses.

When the number of revolutions of the spindle motor 8 approaches a steady state described later, sector pulses can be detected.

An RF signal reproduced from a magnetic head 16 provided at the tip of the arm 9 that moves in the radial direction of the disk 10 is supplied to a pulse detection circuit 18 via a head amplifier 17.

In the pulse detection circuit 21, servo information, data, and the like are separated from the RF signal described above, and the servo information, data, and the like are separated into a head position detection circuit 19, a rotation speed detection circuit 1, and the like.
3. Each is supplied to the data extraction circuit 21.

The head position detection circuit 19 detects the position of the magnetic head 16 on the disk 10 at the current time from the address information of the servo information. Then, the current position information of the magnetic head 16 is supplied to the head position control circuit 22.

On the other hand, information about a desired file to be read is supplied to the CPU 5 from the host computer 2.

In the CPU 5, read address information is formed based on the information on the file, and the read address information is supplied to the head position control circuit 22 via the controller 4 as target position information.

The head position control circuit 22 compares the current position information of the magnetic head 16 with target position information supplied from the controller 4, for example, target track position information. Then, a drive signal for causing the magnetic head 16 to perform a seek operation to the target track or a drive signal for causing the magnetic head 16 to track the target track is supplied to the driver circuit 23.

The driver circuit 23 rotates the arm 9 in the radial direction of the disk 10 based on the above-described drive signal, and
16 seek operation on the target track, or arm 9
The voice coil motor 24 is controlled so as to track the target track of the disk 10.

In the rotation speed detection circuit 13, phase control is performed based on sector pulses obtained from servo information. The phase control based on the sector pulse is performed using a counter as in the case of the FG pulse described above. The difference between the counted number of clocks CLK and the reference value is supplied to the rotation control circuit 15 as a phase error.

In the rotation control circuit 15, a drive signal having a level corresponding to the phase error is formed and supplied to the driver circuit 12.

The driver circuit 12 performs servo control on the rotation speed of the spindle motor 8 based on the above-described drive signal.

As a result, the head amplifier 17, the pulse detection circuit 18, the rotation speed detection circuit 13, the rotation control circuit 15, and the driver circuit 12 constitute a servo system using sector pulses.

In the data extraction circuit 21, the reproduced data is separated, and data for one sector is supplied to the buffer RAM 11 via the controller 4.

The controller 4 writes the above data in the buffer RAM 11 under the control of the CPU 5. Controller 4 is a CPU
Read data from buffer RAM 11 based on the control of 5,
The data is supplied to the host computer 2 in parallel via the interface 3.

In the following, a description will be given of how to change the sector corresponding to the noise generation cycle when the noise occurs in synchronization with the power supply voltage cycle.

FIG. 2A shows the waveform of the power supply voltage VAC and the noise NO, and FIG. 2B shows the sector format. Assuming that the frequency of the power supply voltage VAC is, for example, 60 Hz, the period T is (1/60) seconds. Noise NO1, N
Since O2 is generated in synchronization with the frequency of the power supply voltage VAC, O2 is periodically superimposed on a fixed position of the waveform of the power supply voltage VAC as illustrated. In FIG. 2B, the timing of the sector SE3 is the data transfer time TO.

On the other hand, the steady rotation speed of the spindle motor 8 is set by the following equation.

R = [(N + 2) / N] × 3600 In the above equation, R is the number of revolutions (rpm), and N is the number of sectors per track.

As is apparent from the above equation, the rotation speed of the spindle motor 8 is changed in a direction to advance at least two sectors or more based on 3600 rpm. This is Disk 10
This is to prevent the number of sectors SE formed on the spindle motor 8 from increasing as the number of revolutions of the spindle motor 8 approaches 3000 rpm, thereby preventing access from becoming slow.

As described above, since the rotation speed of the spindle motor 8 is advanced by at least two sectors or more per track,
As shown in the sector format of FIG. 2B, for example, in the first cycle of the power supply voltage VAC, the sector SE2 corresponds to the noise NO1, and in the second cycle, the sector SE4 corresponds to the noise NO2.
Noise NO according to the cycle of the power supply voltage VAC
1, the sector corresponding to NO2 also changes from sector SE2 to SE4. That is, even if the sector SE2 cannot be read due to the noise NO1 in the first cycle of the power supply voltage VAC,
By performing extra read operation once, the power supply voltage VA
In the second cycle of C, reading of the sector SE2 becomes possible.

Also, since the number of revolutions of the spindle motor 8 for rotating the disk 10 is advanced by at least two sectors or more per track, the sector corresponding to the generation cycle of the noises NO1 and NO2 is changed from the sector SE2 to the sector SE4. Even when the transfer time TO for supplying the reproduced data to the host computer 2 via the buffer RAM 11 is considered, the read operation for the sector SE2 can be completed again before the noise NO2 occurs, and the influence of the noise NO2 , The read operation can be performed.

In addition, as described above, since the rotation speed of the spindle motor 8 is shifted to be advanced by at least two sectors or more, it is possible to prevent deterioration of the rotation waiting time.

Further, in a system equipped with such a hard disk drive device 1, specifications relating to noise, such as specifications for a power supply, system shielding, and design conditions around the ground, can be relaxed, and costs can be reduced.

In this embodiment, the read operation in the reproducing system is described. However, the present invention is not limited to this, and can be applied to the write operation in the recording system.

〔The invention's effect〕

According to the disk drive device of the present invention, the number of rotations of the spindle motor for rotating the disk-shaped recording medium is advanced by at least two sectors per track to change the sector corresponding to the noise generation cycle. Even if noise is generated in synchronization with the cycle of the power supply voltage and the noise is superimposed on the power supply voltage, there is an effect that the sector can always be read or written by performing one extra read operation or write operation.

Further, as described above, since the rotation speed of the spindle motor is shifted to be advanced by at least two sectors or more, there is an effect that deterioration of the rotation waiting time can be prevented.

Further, there is an effect that specifications relating to noise, such as specifications for a power source, design conditions for a system shield, and surroundings of the ground, can be relaxed, and costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a diagram showing a noise period and a sector format in one embodiment, and FIG. 3 is a noise period and a sector format in a conventional example. FIG. Description of the main symbols in the drawings 1: hard disk drive device, 8: spindle motor,
10: Disk, R: Number of revolutions, N: Number of sectors, TO: Period, NO1, N
O2: Noise, VAC: Power supply voltage.

Claims (1)

(57) [Claims] In a disk drive device provided with a spindle motor for rotating a disk-shaped recording medium, the number of rotations of the spindle motor is represented by R ≧ [(N + 2) / N] × 3600 (R is the number of rotations (rpm)). , N is the number of sectors per track).