KR100604830B1 - Apparatus for controlling read current according to temperature and disc drive using the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data storage device and a control method thereof, and more particularly, to a read current control method according to temperature for varying a read current supplied to a head of a disk drive to an optimum value according to a change in temperature. The disk drive used.

The read current control apparatus according to the temperature according to the present invention is a data storage system, comprising: a bias circuit for varying a direct current voltage output according to a temperature using a temperature sensing element and a direct current bias terminal for outputting a direct current voltage output from the bias circuit; And a driver circuit for varying the read current supplied to the head according to the voltage applied to the read current bias terminal.

Description

Apparatus for controlling read current according to temperature and disc drive using the same}

1 is a plan view of a configuration of a hard disk drive to which the present invention is applied.

2 is an electrical circuit diagram of a hard disk drive to which a read current control device according to a temperature according to the present invention is applied.

3 is a block diagram of a read current control device according to the temperature according to the present invention.

4 is a characteristic graph of bias voltage according to temperature applied to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data storage device and a control method thereof, and more particularly, to a read current control method according to temperature for varying a read current supplied to a head of a disk drive to an optimum value according to a change in temperature. The disk drive used.

In general, a hard disk drive, which is one of data storage devices, contributes to computer system operation by reproducing data recorded on a disk by a magnetic head or by recording user data on the disk. Such hard disk drives are increasingly used as storage media for A / V (Audio / Video) devices in multimedia systems due to their increased storage capacity.

The hard disk drive includes a plurality of magnetic heads coupled with rotating disks. The head records and reads information by magnetizing the disk surface and sensing the magnetic field. Magnetic heads have been developed that have a recording element for magnetizing the disc and a separate reading element for sensing the magnetic field of the disc. The readout element is typically composed of a magneto-resistive material. The magnetoresistive material has the property that the resistance changes in accordance with the magnetic field of the disk. A head having a magnetoresistive reading element is generally referred to as a magneto-resistive (MR) head.

At low temperatures, the hard disk drive has an increased coercive force (Hc) due to the disk's magnetic physical properties, making it harder to read data from the disk than at room or high temperatures. Accordingly, it is necessary to change the read current according to the temperature.

In the prior art, a table of read current values for temperature was used to determine read current values for sensed temperatures. Accordingly, according to the related art, since the read current is discontinuously changed at a constant temperature interval, there is a problem in that the read current value cannot be precisely and continuously controlled to an optimum value according to the ambient temperature.

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a method of controlling a read current according to temperature for controlling the disk drive read current to be continuously and precisely changed to an optimal value according to the ambient temperature, and using the same. Is to provide a disk drive.

In order to achieve the above technical problem, a read current control apparatus according to a temperature according to the present invention includes a bias circuit for varying a DC voltage output according to a temperature using a temperature sensing element and a bias circuit in a data storage system. And a driver circuit for connecting the DC voltage to the read current bias terminal to vary the read current supplied to the head according to the voltage applied to the read current bias terminal.

In order to achieve the above technical problem, a disk drive according to the present invention includes a disk storing data, writing data to the disk according to a write current, or sensing data from the disk according to a read current. Head, a host interface for performing data transmission / reception processing with a host device, a buffer for storing data received from the host device via the host interface in a write mode, and a data read from the disc in read mode; A controller for analyzing a command received through the host interface and executing a corresponding control process, for writing data output from the buffer to the disk, or for reproducing data read from the disk. A write / read channel that executes data processing and a read current control circuit that continuously varies the read current in response to a change in temperature in the data read mode, amplifying the signal sensed from the disk in the head in accordance with the read current And a preamplifier.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 shows a configuration of a disk drive 10 to which the present invention is applied. The drive 10 includes at least one magnetic disk 12 that is rotated by a spindle motor 14. The disk drive 10 also includes a transducer 16 located adjacent to the disk surface 18.

The transducer 16 can read or write information on the rotating disk 12 by sensing and magnetizing the magnetic field of each disk 12. Typically transducer 16 is coupled to each disk surface 18. Although illustrated and described as a single transducer 16, it should be understood that this consists of a write transducer for magnetizing the disc 12 and a separate read transducer for sensing the magnetic field of the disc 12. Read transducers are constructed from Magneto-Resistive (MR) devices. The transducer 16 is also commonly referred to as a head.

The transducer 16 can be integrated into the slider 20. The slider 20 is structured to create an air bearing between the transducer 16 and the disk surface 18. The slider 20 is coupled to the head gimbal assembly 22. The head gimbal assembly 22 is attached to an actuator arm 24 having a voice coil 26. The voice coil 26 is located adjacent to the magnetic assembly 28 that specifies the voice coil motor 30 (VCM). The current supplied to the voice coil 26 generates a torque for rotating the actuator arm 24 relative to the bearing assembly 32. Rotation of the actuator arm 24 moves the transducer 16 across the disk surface 18.

The information is typically stored in an annular track of the disc 12. Each track 34 generally includes a plurality of sectors. Each sector includes a data field and an identification field. The identification field is composed of a gray code identifying a sector and a track (cylinder). The transducer 16 is moved across the disk surface 18 to read or write information on other tracks.

2 shows an electrical circuit of a disk drive to which the present invention is applied.

As shown in FIG. 2, the disc drive according to the present invention includes a disc 12, a converter 16, a preamplifier 210, a write / read channel 220, a buffer 230, a controller 240, a ROM. 250, a RAM 260, a voice coil motor driver 270, and a host interface 280.

The ROM 250 stores various programs and data for controlling the disk drive, and the RAM 260 is loaded with data necessary for the disk drive operation read from the maintenance area of the disk 12 at every boot.

The buffer 230 sequentially stores data received from the host device through the host interface 280 in the write mode, and sequentially stores data read from the disk 12 in the read mode.

The preamplifier 210 includes an amplifier circuit for amplifying a signal sensed by the converter 16 and a read current control circuit for supplying an optimum read current according to temperature to the converter 16. Of course, a write current control circuit for supplying write current is also built in.

First, the operation of a general disk drive will be described.

In the data read mode, the disc drive amplifies the electrical signal sensed by the transducer 16 (also called a head) from the disc 12 to facilitate signal processing in the preamplifier 210. Then, in the recording / reading channel 220, the amplified analog signal is encoded into a digital signal that can be read by a host device (not shown), converted into stream data, and temporarily stored in the buffer 230, and then the host. It transmits to the host device through the interface 280.

In the data write mode, the disk drive receives data from the host device through the host interface 280 and temporarily stores the data in the buffer 230, and then outputs data from the buffer 230 to the write / read channel 220. After the conversion into a binary data stream suitable for the recording channel, the write current amplified by the preamplifier 210 is recorded on the disc 12 through the converter 16.

The controller 240 controls the disk drive as a whole, and analyzes a command received through the host interface 280 to execute the command.

The controller 240 is also coupled to the VCM driver 270 for supplying a drive current to the voice coil 26 and to the VCM driver 270 to control the excitation of the VCM and the movement of the transducer 16. Supply the control signal.

Then, the read current control device according to the temperature according to the present invention built in the preamplifier 210 will be described in detail.

As shown in FIG. 3, the read current control apparatus according to the temperature according to the present invention includes a bias circuit 310, a driver circuit 320, and an MR head (MR Head: Magneto-Resistive Head, 330).

At low temperatures, the hard disk drive has an increased coercive force (Hc) due to the disk's magnetic physical properties, making it harder to read data from the disk than at room or high temperatures. Accordingly, it is necessary to change the read current according to the temperature. In other words, as the temperature decreases, the read current must be increased to achieve optimal data read performance.

The bias circuit 310 includes a resistor R1 and a thermistor 310-1, the circuit configuration connects the resistor R1 and the thermistor 310-1 in series, the resistor R1 is connected to a DC power supply line (Vcc), The thermistor 310-1 is connected to the ground line, and the connection terminal of the resistor R1 and the thermistor 310-1 is set as an output terminal and connected to the read current bias terminal of the driver circuit 320.

Thermistor 310-1 is a temperature sensing means, and the resistance value decreases in proportion to the increase in temperature. That is, the resistance value is increased at low temperatures, and the resistance value is decreased at high temperatures. The change rate of the resistance value according to the temperature change of the thermistor 330-1 is designed to generate an optimal read current value experimentally determined according to the temperature in the disk drive.

Accordingly, the bias voltage V _READ applied to the read current bias terminal has a voltage-temperature characteristic as shown in FIG. 4. That is, as the temperature decreases, the bias voltage V _READ increases.

The driver circuit 320 supplies a read current to the MR head 330 according to the bias voltage V _READ applied to the read current bias terminal. Therefore, the read current supplied to the MR head 330 is interlocked according to the bias voltage V _READ . As a result, even if the ambient temperature of the hard disk drive changes instantaneously, the read current supplied to the MR head 330 can be continuously and precisely determined to an optimum value according to the change of temperature.

Specific embodiments shown and described in the accompanying drawings are only to be understood as an example of the present invention, not to limit the scope of the invention, but also within the scope of the technical spirit described in the present invention in the technical field to which the present invention belongs As various other changes may occur, it is obvious that the invention is not limited to the specific constructions and arrangements shown or described. That is, it is a matter of course that the present invention can be applied not only to various disk drives including hard disk drives, but also to various kinds of data storage devices.

As described above, according to the present invention, by controlling the read current of the disk drive to be continuously changed to an optimum value according to the ambient temperature, the effect of not having to store a table of read current values for temperature in the memory is achieved. In addition, the effect of varying the read current continuously and precisely according to the change in temperature is generated.

Claims (9)

In a data storage system, A bias circuit for varying a DC voltage output in accordance with a temperature change by using a temperature sensing element in which a resistance value changes in response to a temperature change; And And a driver circuit for connecting the DC voltage output from the bias circuit to a read current bias terminal to vary the read current supplied to the head in accordance with the voltage applied to the read current bias terminal. Current control device. The apparatus of claim 1, wherein the bias circuit is designed such that the DC voltage is increased in proportion to a decrease in temperature. The apparatus of claim 1, wherein the temperature sensing element comprises a thermistor. The method of claim 1, wherein the bias circuit is Connect a resistor and thermistor in series, connect the resistor to a DC power line, connect the thermistor to a ground line, and determine the connection terminal of the resistor and thermistor as an output terminal to a read current bias terminal of the driver circuit. Lead current control device according to the temperature characterized in that it comprises a circuit for connecting. In the data storage device, A disk for storing data; A head for writing data to the disk in accordance with a write current or sensing data from the disk in accordance with a read current; A host interface for performing data transmission / reception processing with the host device; A buffer for storing data received from the host device through the host interface in a write mode and storing data read from the disk in a read mode; A controller for analyzing a command received through the host interface and executing a corresponding control process; A recording / reading channel for performing data processing for recording data output from the buffer to the disk or reproducing data read from the disk; And A read current control circuit for continuously changing a read current in accordance with a change in temperature in a data read mode, and a preamplifier for amplifying a signal sensed from the disc in the head according to the read current, The read current control circuit is connected to a read current bias terminal by connecting a direct current voltage, which is variable according to a temperature change, to a read current bias terminal by using a temperature sensing element whose resistance value changes according to a temperature change. Therefore, the disc drive characterized by varying the read current supplied to the head. The circuit of claim 5, wherein the read current control circuit comprises: A bias circuit for varying the DC voltage output in accordance with the temperature by using the temperature sensing element; And And a driver circuit connecting the DC voltage output from the bias circuit to a read current bias terminal to vary the read current supplied to the head in accordance with the voltage applied to the read current bias terminal. 7. The disk drive of claim 6, wherein the bias circuit is designed such that the direct current voltage is increased in proportion to a decrease in temperature. 7. The disk drive of claim 6, wherein the temperature sensing element comprises a thermistor. The method of claim 6, wherein the bias circuit is Connect a resistor and thermistor in series, connect the resistor to a DC power line, connect the thermistor to a ground line, and determine the connection terminal of the resistor and thermistor as an output terminal to a read current bias terminal of the driver circuit. And a circuit for connecting.

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