JP3075365B2 - Head access control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head access control device, and more particularly to a head access control device for a file device using a battery as a power supply.

In recent years, as portable personal computers and the like have been reduced in size, file devices such as magnetic disk devices as external storage devices have also been reduced in size.
Low power consumption has been required. Therefore, an AC power source or a battery (rechargeable battery) is generally used as a power source for a portable personal computer. However, especially when a battery is used as a power source, there is a limit to the battery drive time, and the access to the head of the file device is limited. It is necessary to reduce the power consumption of the control as much as possible.

[0003]

2. Description of the Related Art In a magnetic disk drive, a head access control device is used for moving a head for reading and writing data at high speed on a medium surface of a magnetic disk and positioning the head on a target track. . FIG. 7 shows a configuration diagram of an example of a conventional head access control device.
In FIG. 1, reference numeral 1 denotes an actuator, which includes a head for reading and writing data from and to a magnetic disk, a head arm for supporting the head, a carriage (none of which is shown) on which the head arm is mounted, and the like. Reference numeral 2 denotes a state observer which is a circuit for observing or calculating the current position and the current moving speed of the actuator 1 on the magnetic disk based on a servo signal read by the head.

[0004] 3 for moving the actuator 1 to the target track by acceleration and deceleration of the pattern generator, acceleration, the circuit previously stores reduced <br/> speed pattern, with respect to the distance, for example to the target track deceleration degree pattern data is stored in the form of a table the read-only memory (RO
M).

[0005] 4 target velocity generator for generating a speed corresponding to the acceleration and deceleration of the pattern, 5 calculator, 6 gain setter for setting a gain of the entire apparatus, 7 is a power amplifier for power amplification, 8 Is a voice coil motor (VC) for moving the actuator 1 in the radial direction of the magnetic disk.
M). Reference numeral 9 denotes a battery for applying a power supply voltage to each of the above components.

[0006] In the head access control device of such a configuration, when the target track instruction input is made to the acceleration and deceleration of the pattern generator 3, the acceleration and deceleration of the pattern generator 3 current actuator from the target track and the state observer 2 generating a deceleration degree pattern corresponding to the distance between the track position. Target speed generator 4 generates a target velocity signal corresponding to the acceleration and deceleration of the pattern supplied to the calculator 5, wherein to perform a subtraction of the current velocity signal of the actuator 1 from state observers 2.

The speed error signal extracted from the arithmetic unit 5 passes through a gain setting unit 6 and a power amplifier 7 to output a VCM signal.
8 is supplied as a drive current, and drives the VCM 8 at a speed according to the level and in a direction according to the polarity. The actuator 1 is moved in a direction and a speed corresponding to the driving direction and the driving speed of the VCM 8, and finally moves to a target track position.

The drive current flowing through the VCM 8 is determined by the power amplifier 7 and the like. Conventionally, a current having the maximum capability of the power amplifier 7 is supplied as much as possible for both acceleration and deceleration, and the access time at the time of head access is shortened as much as possible. ing.

[0009]

[SUMMARY OF THE INVENTION] However, the above conventional apparatus, the power consumption of VCM8 during head access is a significant fraction of an overall power consumption of the magnetic disk device, acceleration or deceleration of the pattern generator deceleration degree pattern generated by 3, for example, as shown in FIG. 8, VCM
8 (acceleration when the driving current is positive, negative when the deceleration) pattern for the driving current is changed with time is, the above acceleration time according to the distance to the target track position, the deceleration phase <br/> between However, since the pattern shape itself is a constant pattern set so that the current having the maximum capacity of the power amplifier 7 always flows, the battery 9 is greatly consumed and the magnetic disk device cannot be used for a long time. was there.

The present invention has been made in view of the above points, and has as its object to provide a head access control apparatus which solves the above-mentioned problems by changing an access time according to a remaining operation time of a battery. And

[0011]

FIG. 1 is a block diagram showing the principle of the present invention. The present invention uses a battery 11 as a device power supply, and outputs a motor drive signal to a motor using a speed control system 13 based on an acceleration / deceleration pattern obtained from a target track position on a recording medium and a current position of an actuator 12 including a head. The apparatus for positioning the actuator 12 driven by the motor 14 to the target track position by supplying the battery 14 to the target track 14 has a monitoring unit 15 for monitoring the remaining operating time of the battery 11 and an access time variable unit 16 . Things.

Here, the access time varying means 16 is a supervisor.
The remaining operation of the battery 11 based on the monitoring result of the visual unit 15
The shorter the time, the shorter the distance to the same target track position
The access time for separation is greatly varied.

[0013]

The power consumption of the motor 14 during head access is
It becomes larger as the access time is shorter. Thus, the present invention
Then, the remaining access time of the battery 11 is
The longer the operating time, the longer the access time
The remaining operating time of the battery 11 is short.
Indeed, the power consumption of the motor 14 can be reduced.
You.

[0014]

FIG. 2 is a block diagram showing one embodiment of the present invention. In the figure, the same components as those in FIGS. 1 and 7 are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 2, a battery monitor 21 constantly monitors the output voltage of the battery 9 by detecting the output voltage of the battery 9. 22 is acceleration <br/> speed pattern generator, constitute a changing means 16 of the access time, even the distance to the same target track position, in accordance with the monitoring result from the battery monitoring device 21 to generate a different or deceleration pattern.

[0015] Figure 3 shows a first embodiment of the acceleration and deceleration degree pattern generated by the acceleration and deceleration of the pattern generator 22. FIGS. 3A to 3C respectively show the distance from the current track position of the actuator 1 to the target track position (access distance).
The acceleration and deceleration of the pattern when the same, but the maximum current value Imax of VCM8 the same, are different from each other form of acceleration and deceleration patterns.

[0016] FIG. 3 (A) in the acceleration and deceleration of the pattern when the access time shortest time control, a conventional same pattern, just half the time T1 / 2 of the access time T1 of pressurized <br/> speed the maximum current value -Ima of deceleration from the maximum current value Imax
Switching to x. Further, FIG. 3 (C) in the acceleration and deceleration of the pattern when the voice coil power minimum control, by varying linearly from a maximum pressure <br/> speed current value Imax to the maximum deceleration current value -Imax , The longest access time T3 is obtained.

FIG. 3 (B) is a view similar to FIG.
In deceleration patterns in the transition mode to (C), switching from the maximum acceleration value Imax until maximum deceleration current -Imax is, half of the access time T2 time T2 /
It is performed linearly during a time width kT centered at 2.
Here, the coefficient k is 0 <k <1. Note that acceleration and deceleration of the pattern of FIG. 3 (A) corresponds to the case of the k = 0, 3
Deceleration degree pattern (C) corresponds to the case of the k = 1.

The acceleration and deceleration of the pattern generator 22 on the basis of the monitoring result from the battery monitoring device 21, the coefficient k when the remaining operating time is equal to or greater than a predetermined reference value of the battery 9 is "0", namely FIG 3 (A ) acceleration and deceleration of the pattern at the shortest access time control occurs as shown in, and inputs the target speed generator 4. As described below with reference to FIG. 7, the actuator 1 is accelerated toward the target track position, decelerated, and positioned at the target track position. The access time at this time is T1.

[0019] The monitoring result from acceleration and deceleration of the pattern generator 22 is the battery monitoring device 21, when the remaining operating time of the battery 9 becomes smaller than the predetermined reference value, the coefficient k in inverse proportion to the value Acceleration / deceleration by continuously changing the value of
Generate a degree pattern. Therefore, according to the deceleration pattern generated from the acceleration and deceleration of the pattern generator 22, the remaining operating time of the battery 9 becomes smaller than the predetermined reference value,
The slope of the linear portion of up to maximum deceleration current -Imax generates a deceleration degree pattern becomes gentle.

[0020] Thus, if the access distance and the maximum current value Imax is constant, the voice coil motor power minimum control acceleration and deceleration of the pattern upon the occurrence of FIG. 3 (C), FIG. 3
Power consumption P of VCM8 than the deceleration degree pattern generation during the access time shortest time control of (A) is 0.408 times (= 1 / √6 times), access time T is 1.225 times (= √ 3 / √2 times). The relationship between the access time T and the power consumption P when the coefficient k is changed from “0” to “1” is as shown in FIG.

Thus, according to the present embodiment, the power consumption P of the VCM 8 is reduced as the remaining operation time of the battery 9 decreases, so that the operation time of the battery 9 is increased as compared with the conventional case. Can be.

Next, a second embodiment of the acceleration and deceleration of the pattern acceleration speed pattern generator 22 generates by referring to FIG. Figure 5 (A), (B) is a deceleration of the pattern when the same respectively access distance, but both are the same shape as the acceleration and deceleration of the pattern when the access time shortest time control, maximum drive of VCM8 current value (maximum acceleration electrostatic <br/> current values and maximum deceleration current value) Imax is different.

[0023] FIG. 5 (A), acceleration and deceleration of pattern <br/> down the remaining operating time of the battery 9 is generated when the predetermined reference value or more, the maximum acceleration current value Imax, the maximum deceleration a degree current value -Imax, shortest at this time of the access time T
a is obtained.

[0024] FIG. 5 (B) the maximum acceleration current value (1-k in deceleration degree pattern <br/> over emissions that are generated when the remaining operating time is less than the predetermined reference value of the battery 9 ) Imax, maximum deceleration
The current value is expressed by-(1-k) Imax.

The present embodiment acceleration speed pattern generator in 22, when the remaining operating time of the battery 9 becomes smaller than the predetermined reference value, the value of k coefficients in inverse proportion to the value "0" from Acceleration / deceleration continuously increased toward “1”
Generate a degree pattern. Therefore, deceleration degree pattern generated from acceleration and deceleration of the pattern generator 22 according to the remaining run time of the battery becomes smaller than the predetermined reference value in this embodiment, the positive acceleration speed pattern, negative peak value becomes small to generate the (amplitude is small) deceleration degree pattern. However, when the value of the coefficient k is close to "1", the access time T becomes too long, which is not practical.

The relationship between the power consumption P of the deceleration degree pattern generation during the access time T and VCM8 of this embodiment becomes as shown in FIG. 6, compared to the first embodiment described above, increase or decrease of the power consumption P Although the effect is great, the access time T changes abruptly. However, in this embodiment, as in the first embodiment, the life of the battery 9 can be made longer than that of the conventional battery.

[0027]

As described above, according to the present invention, as the remaining operating time of the battery decreases, the power consumption of the motor can be reduced, so that the remaining operating time of the battery can be made longer than before. Therefore, the present invention has such features that the operating time of the file device using the battery as a power source can be made longer than before.

[Brief description of the drawings]

FIG. 1 is a principle block diagram of the present invention.

FIG. 2 is a configuration diagram of one embodiment of the present invention.

3 is an explanatory view of a first embodiment of the acceleration and deceleration of the pattern in the present invention.

It is a diagram showing the relationship between the access time and the VCM power in acceleration and deceleration of the pattern upon the occurrence of FIG. 3. FIG.

5 is an explanatory view of a second embodiment of the acceleration and deceleration of the pattern in the present invention.

6 is a diagram showing the relationship between the access time and the VCM power in acceleration and deceleration of the pattern upon the occurrence of FIG.

FIG. 7 is a configuration diagram of an example of a conventional device.

8 is an explanatory view of the acceleration and deceleration of the pattern of the conventional apparatus shown in FIG.

[Explanation of symbols]

11 battery 12 actuator 13 Motor 15 monitoring unit 16 the access time variable means 21 battery monitor unit 22 acceleration speed pattern generator

Continuation of the front page (56) References JP-A-2-198074 (JP, A) JP-A-50-115015 (JP, A)

Claims (2)

(57) [Claims] (1)A battery is used as the device power supply,
Actuator including target track position and head on recording medium
Based on acceleration / deceleration pattern obtained from current position of eta
Supply motor drive signal to motor using speed control system
The actuator driven by the motor
Data of the head for positioning the data at the target track position.
Access control device, wherein the acceleration / deceleration pattern is
A constant acceleration period and a predetermined deceleration equal to the predetermined acceleration period
The predetermined acceleration so that the period and the acceleration / deceleration change linearly.
Acceleration / deceleration switching to switch from the degree period to the predetermined deceleration period
In the period consisting of Monitoring means for monitoring the voltage of the battery, As the voltage of the battery drops below a predetermined reference value,
The predetermined acceleration period and the predetermined deceleration period are equally short.
The acceleration / deceleration switching period is extended, and
Acceleration period, the deceleration period, the acceleration / deceleration switching period,
The acceleration / deceleration pattern is set so that the sum of
Acceleration / deceleration pattern setting means.
Head access control device. (2)A battery is used as the device power supply,
Actuator including target track position and head on recording medium
Based on acceleration / deceleration pattern obtained from current position of eta
Supply motor drive signal to motor using speed control system
The actuator driven by the motor
Data of the head for positioning the data at the target track position.
Access control device, wherein the acceleration / deceleration pattern is
A constant acceleration period and a predetermined deceleration equal to the predetermined acceleration period
In the period consisting of Monitoring means for monitoring the voltage of the battery, As the voltage of the battery drops below a predetermined reference value,
The predetermined acceleration period and the predetermined deceleration period are equally extended.
And the predetermined acceleration and the predetermined deceleration are equal.
Set the acceleration / deceleration pattern so that it is reduced to minutes
Acceleration / deceleration pattern setting means.
Head access control device.