JP3099370B2 - Disk device power save method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive for reducing power consumption by positioning a head moving mechanism (hereinafter referred to as an "actuator") in a cylinder having a minimum external force when a controller is not in an access state. Related to power save system.

With the recent increase in the scale of computer systems, there is a demand for lower power consumption of the systems. There is also a need for lower power consumption in magnetic disk drives.

[0003]

2. Description of the Related Art In a conventional magnetic disk drive, when data is read from or written to a disk, even after the data has been read / written, the data is read from the disk.
The head stays at the cylinder that performed the read / write,
The position was kept until the next access command came.

However, in order to keep holding a certain cylinder position, it is necessary to keep flowing a holding current for positioning the actuator at that position. The holding current needs only a force for canceling an external force for moving the actuator. This external force is the reaction force due to the flexure of the flexible printed board that supplies signals and drive current to the actuator, the wind pressure due to the rotation of the disk, and the force of a spring that moves the actuator to a certain position when stopped. It is desirable to be as small as possible.

FIG. 4 shows the structure of a conventional disk drive.
In the figure, reference numeral 26 denotes a head for reading / writing a disk, 2
4 is an actuator for moving the head 26, 21 is a drive circuit for driving the actuator 24, 22 is a measurement circuit for measuring the drive current supplied by the drive circuit 21, and 16 is a correction input for correcting a deviation of the head from the track. Is a controller for controlling the disk drive, 15 is a program stored in the internal memory of the controller 23, and an initial state in which the measuring circuit measures the holding current in each cylinder in an initial state after power-on. This is a drive current measurement function.

FIG. 5 shows the waveform of the drive current supplied by the drive circuit 21 when the cylinder moves. The figure shows the peak value of the drive current, and a current of about 1.5 amps is passed as a pulse to move the actuator and move the head. It is necessary to supply a holding current to maintain the position after the movement is completed. This holding current is, for example, about 1/100 of the peak value, but is shown as the second holding current in the figure. The value of the holding current is determined by the above-mentioned external force, and unless the drive circuit 21 supplies an appropriate holding current at an appropriate time, the position of the head is not stabilized early. Therefore, the value of the holding current at each cylinder position is measured in the initial state after the power is turned on by the initial drive current measurement function 15 and stored in the internal memory of the controller 23. During driving, the holding current is supplied immediately after the end of the driving current to stabilize the cylinder position. Also, the first holding current in the figure is the holding current at the first position.

As described above, a holding current is required to stabilize the cylinder position, and the value of the holding current differs depending on the cylinder position. The holding current needs to be supplied even when the disk device is not reading or writing. there were.

[0008]

Therefore, if a read / write operation is performed on a cylinder having a large holding current applied to the actuator, and thereafter access is not performed for a long time, the actuator is only used to stay on the cylinder. There was a problem that considerable power was consumed.

In view of such a point, the present invention is a means for realizing low power consumption of a disk drive by positioning the actuator in the cylinder where the external force applied to the actuator is minimum when no access is being performed. The purpose is to provide.

[0010]

The above-mentioned problems are solved by a power saving system for a disk drive constructed as follows.

FIG. 1 is a diagram illustrating the principle of the present invention. An actuator 24 for positioning the read / write head to the cylinder,
A drive circuit 23 that drives the actuator 24, a measurement circuit 22 that measures a drive current that drives the drive circuit 23,
A controller 23 for controlling the disk device, and in an initial state after power-on, the measuring circuit 22 measures a holding current at each cylinder position, and stores the measured value in the controller 23. Inside the controller 23, the cylinder having the smallest holding current is determined from the measured value, and when the controller 23 is not in the access state, an instruction to position the actuator 24 at the cylinder having the smallest holding current is provided. Function 25
Is provided.

[0012]

In the initial state after the power is turned on, the measuring circuit 22
Measures the holding current at each cylinder position and accumulates the measured values inside the controller 23. Power saving function
When the controller 23 is not in the access state, the cylinder 25 determines the cylinder having the smallest holding current from the measured value and issues an instruction to position the actuator 24 on the cylinder.

[0013]

FIG. 2 is a block diagram of an embodiment of the present invention. In the figure, reference numeral 25 denotes a power saving function for judging the cylinder having the smallest holding current from the measured value when the controller 23 is not in the access state and instructing the cylinder 24 to position the actuator 24. In addition, items having the same reference numerals as those in FIG. 4 are the same.

FIG. 3 is a flowchart of the power saving function 25. In step 81, the power saving function 25 constantly monitors whether the controller 23 has received an access command.
If there is an access command, control is transferred to the access command processing unit in step 84. If there is no access command, step 82
Proceed to. In step 82, the power saving function 25 knows the cylinder position where the holding current is the smallest from the value of the holding current of each cylinder stored in the internal memory of the controller 23. Steps
At 83, the drive circuit 21 is driven to move the actuator to the cylinder position, and the position of the actuator is moved to the cylinder having the smallest holding current. With the above-described configuration, it is possible to reduce the non-operating holding current and reduce the power consumption.

[0015]

As is apparent from the above description, according to the present invention, when no access is performed, the drive current applied to the actuator is positioned at the cylinder having the smallest operation, thereby reducing the disk drive consumption. There is a remarkable industrial effect of providing means for realizing electric power.

[Brief description of the drawings]

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

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

FIG. 3 is a control flowchart of a power saving function.

FIG. 4 is a configuration diagram of a conventional disk device.

FIG. 5 is a driving current waveform of an actuator.

[Explanation of symbols]

 15 Initial drive current measurement function 16 Servo circuit 21 Drive circuit 22 Measurement circuit 23 Controller 24 Actuator 25 Power saving function 26 Head 81 to 84 Operation steps

Continuation of the front page (56) References JP-A-3-20764 (JP, A) JP-A-3-127392 (JP, A) JP-A-59-139177 (JP, A) JP-A-60-29968 (JP) , A) Real opening 63-168671 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 19/00 501 G11B 21/12

Claims (1)

(57) [Claims] 1. A head moving mechanism (actuator) (24) for positioning a read / write head on a cylinder, a drive circuit (21) for driving the actuator (24), and a drive current for driving the drive circuit (21). A measuring circuit (22) for measuring;
A controller (23) for controlling the disk device, and in an initial state after power-on, the measuring circuit (22) measures a holding current at each cylinder position, and stores the measured value in the controller (23). In the storage disk device,
Inside the controller (23), the cylinder having the smallest holding current is determined from the measured value, and when the controller (23) is not in the access state, the actuator (24) is positioned at the cylinder having the smallest holding current. A power saving method for a disk device, comprising a power saving function (25) for giving an instruction.