JPH08279238A - Disk device - Google Patents

Abstract

PURPOSE: To prevent other track data from being destructed due to the head upon receipt of vibration and impact from the outside by inhibiting the write of data when acceleration of moving the head exceeds an allowable range of a data writing operation. CONSTITUTION: An acceleration detecting signal A from an acceleration sensor 6 and a reference acceleration signal B corresponding to the max. allowable acceleration at the time of writing data on a target track by the head 4 are inputted to a comparator 11. Then, when the signal A is lower than the signal B, a low level signal C is outputted, and when the signal A is higher than the signal B, a high level signal C is outputted. Then, a write-in gate signal D is low at the writing time, and becomes its high level in other cases. Consequently, a write enable/inhibit signal E of an output of an OR circuit 12 becomes the write inhibit high level when the signal A exceeds the signal B. Then, a read/write circuit 7 is operated when the signal E is at the write enable state of low level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk device such as a hard disk device and a floppy disk device.

[0002]

2. Description of the Related Art Conventionally, in information processing devices such as word processors and computers, magnetic disk devices such as hard disk devices and floppy disk devices have been used as external storage means.

For example, in a floppy disk device, the head is conventionally moved by a steel belt method using a stepping motor, and the head is positioned by positioning (rotating) the stepping motor. And recently, in order to improve the density of recording tracks, servo information is written on the disk,
An increasing number of devices use the above-mentioned disc servo information to position the head with respect to the disc. That is, the servo information is written in advance on the disk, and the servo such as the positioning of the head is performed by using the servo information when the head performs a predetermined operation.

As the servo system of the above-mentioned disk device, there is an intermittent servo system in which servo information is written in several places in one track of the disk. There is a sector servo system as one of the intermittent servo systems, but in this intermittent servo system, servo information cannot be obtained continuously in time.

For example, when a disk in which servo information of 50 places is written on one track is rotated at 300 rpm, it takes 4 ms from obtaining one servo information to obtaining the next servo information of this servo information. Has passed.

Therefore, in the above-described sector servo type disk device, when data is written on the disk by the head, the servo information is obtained intermittently. Therefore, after obtaining some servo information, the servo information next to this servo information is obtained. The position of the head moves if vibration or shock is applied from the outside until it is obtained, but the device cannot recognize that the head position has changed because there is no servo information, and the head cannot be recognized. Since the position cannot be corrected, there is a problem that data is written in another track and the data written in that track is destroyed.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and the head supporting means moves when the vibration or shock is applied from the outside at the time of writing data, so that the head position is changed. It is an object of the present invention to provide a disk device that can prevent the data of other tracks from being damaged even if it changes.

[0008]

In order to achieve the above-mentioned object, a disk device of the present invention includes a head supporting means for supporting a head for writing and reading data to and from the disk, and the head supporting means. An acceleration detecting means provided to detect an acceleration generated by a force applied to the head supporting means; and an acceleration of the head supporting means detected by the acceleration detecting means is a predetermined acceleration,
Specifically, it comprises a control means for prohibiting the head from writing the data to the disk when the acceleration exceeds a range that guarantees the data writing operation to the target track by the head. is there.

In the disk device of the present invention, when the acceleration of the head supporting means detected by the acceleration detecting means exceeds a predetermined acceleration, the operation of writing data on the disk by the head is prohibited. Therefore, even if the head supporting means moves and the head position changes due to external vibration or shock when writing the data, it is possible to prevent the data in the other tracks from being damaged.

Further, in the present invention, the head supporting means is provided with an acceleration detecting means for detecting an acceleration generated by a force such as a vibration or a shock applied to the head supporting means, and the acceleration generated in the head supporting means is directly detected. Therefore, the acceleration can be detected with higher accuracy, and the data destruction can be more reliably eliminated.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic diagram for explaining the configuration of a floppy disk device suitable for explaining the disk device according to the present invention.

In the figure, 1 is a chassis, 2 is a disk motor for driving the disk 3 to rotate, 4 is a head for writing and reading data to and from the disk 3, 5 is a head for holding the head 4 and the head 4 for the disk 3. A carriage 6 that is moved in the radial direction is provided on the carriage 5, and an acceleration sensor that directly detects an acceleration generated in the carriage 5 due to external vibration or impact and outputs a signal corresponding to the detected acceleration, and 7 is a head 4 A read / write circuit for inputting / outputting data for writing data and reading information, and 8 for reading / writing based on the detection result of the acceleration sensor 6.
This is a write inhibit circuit that inhibits the write operation of the head 4 of the write circuit 7.

FIG. 2 is a circuit diagram for explaining the details of the write inhibit circuit 8 of FIG.

The write-inhibit circuit 8 inputs a comparison between the acceleration detection signal A from the acceleration sensor 6 and the reference acceleration signal B, a comparator 11, an output signal C from the comparator 11, and a floppy disk (not shown). Input the write gate signal D from the controller to enable writing
The OR circuit 12 outputs the inhibition signal E.

The output signal C of the comparator 11 is low when the value of the acceleration detection signal A is lower than the value of the reference acceleration signal B corresponding to the maximum acceleration in the range in which the head 4 guarantees the writing operation of the data to the target track. When the value of the acceleration detection signal A exceeds the value of the reference acceleration signal B, the level becomes high. In addition, the write gate signal D
Is at a low level during writing, and is at a high level in other cases. Therefore, the write permission / prohibition signal E output from the OR circuit 12 becomes a high level indicating write prohibition when the value of the acceleration detection signal A exceeds the value of the reference acceleration signal B during writing.

The write enable / disable signal E is output to the read / write circuit 7. The read / write circuit 7, which is also called a read / write amplifier, is a circuit for driving a read / write coil and an erase coil provided in the head. The read / write circuit 7 has a circuit that outputs a write current to the read / write coil based on a data signal input to the read / write circuit 7 when writing data. This circuit operates when the write permission / prohibition signal E indicates write permission (low level). Therefore, when the write enable / prohibit signal E is write-protected (high level), the write current is not output to the read / write coil, and the write of the data signal is prohibited. As the basic circuit of the read / write circuit 7,
Hitachi's HA16642 FDD read / write amplifier and the like are known.

FIG. 3 is a block diagram for explaining the configuration of a system using the floppy disk device of FIG.

In the figure, 21 is a CPU for controlling the system, 22 is a memory for storing data in the host system, and 23 is a CP for data in the memory 22.
Directly accessible U controller separately from U21, 24 floppy disk controller (FD
C) and 25 are the floppy disk devices (FDD) described in FIG.

In this system, the write data stored in the memory 22 by the CPU 21 is read by the DAM controller 23 and sent to the FDC 24.
Then, the data is sent from the FDC 24 to the read / write circuit of the FDD 25 described with reference to FIG. 1, and the data is written to the disk by the head. As a basic circuit of the FDC 24, a μPD765A manufactured by NEC Corporation is known, but an additional circuit is required due to high density (for example, introduction of servo technology). However, since this point is not directly related to the present invention, the description thereof will be omitted.

Next, the operation of the floppy disk device configured as described above will be described.

When storing predetermined data in the disk 3, first, the FDC 24 outputs write data (Wright Data) and a write gate signal (Wright Gate) D. The write gate signal D becomes a write gate signal D (internal write gate signal) which is a result of logically ANDing with the signal indicating that the internal status of the FDD 25 is writable. OR circuit 1 of write inhibit circuit 8
Entered in 2. In the state where the acceleration higher than the specified value is not applied to the carriage 5 (the signal C is at the low level),
A write enable low-level signal is output to the read / write circuit 7, and the read / write circuit 7 writes the data corresponding to the write data sent from the FDC 24 to the disk 3 by the head 4.

During the above-described data write operation, F
When an external force such as an external vibration or shock is applied to the DD 25, the carriage 5 may be affected depending on the magnitude of the force.
Moves at an acceleration that is higher than the acceleration that guarantees the write operation of data to the target track by the head 4, that is, the acceleration that guarantees that the write position of the head 3 does not move on another track. This acceleration is detected by the acceleration sensor 6 and the acceleration detection signal is FDD.
No. 25 is input to the comparator 11 of the write inhibit circuit 8. Then, the comparator 11 outputs a high level signal to the OR circuit 12, the OR circuit 12 outputs a high level signal which is a write-inhibit signal to the read / write circuit 7, and the head 4 transfers the signal to the disk 3. Write operation is prohibited. At this time, if the error signal shown in FIG. 3 is generated based on the write inhibit signal from the OR circuit 12 or the signal that detects the occurrence of over acceleration from the comparator 11, the error signal is sent to the FDC 24. It is possible to recognize that the current writing has been interrupted and rewrite the data. Note that it is not always necessary to send out the Error signal, and if the FDC 24 has a function of performing the verify operation of reading the written data and comparing it with the write data after the write operation is completed, the FDC 24 may be overaccelerated. The interruption of writing can be recognized.

Therefore, in this embodiment, when an external force is applied from the outside, the writing operation of the head 4 is prohibited. Therefore, even in the device of the intermittent servo system such as the sector servo system, the writing operation of the head is performed. It is possible to prevent the data on the adjacent tracks from being destroyed. In particular, in the present embodiment, the acceleration sensor 6 is attached to the carriage 5 that is the head support means and the acceleration generated in the carriage 5 is directly detected, so that it is possible to detect the overacceleration with higher accuracy. It is possible to more reliably eliminate the risk of data destruction due to off-track during the write operation.

In the above-described embodiment, the input of the write gate signal D to the read / write circuit is prohibited, but the IC chip forming the read / write circuit is a chip that prohibits the operation of the chip itself. If the enable terminal is provided, the output signal C of the comparator 11 may be sent to the chip enable terminal to inhibit the write operation.
The present invention is not limited to the floppy disk device, and can be similarly applied to a hard disk device, an optical disk device, etc. in which the head is positioned by the intermittent servo system.

[0026]

As described above, according to the disk device of the present invention, the acceleration of the movement of the head detected by the acceleration detecting means exceeds the acceleration in the range that guarantees the data write operation to the target track. When writing data, even if the intermittent servo method is used, vibration or shock is applied from the outside to the other heads. It is possible to prevent the data in the track from being damaged.

Further, according to the present invention, since the acceleration detecting means is attached to the head supporting means and the acceleration generated in the head supporting means is directly detected, the acceleration can be detected with higher accuracy. It is possible to more reliably eliminate the risk of data destruction due to off-track during the write operation.

[Brief description of drawings]

FIG. 1 is a schematic diagram for explaining a configuration of a floppy disk device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram for explaining details of a write inhibit circuit of FIG.

FIG. 3 is a block diagram for explaining a system using the floppy disk device of FIG.

[Explanation of symbols]

 3 ... Disk 4 ... Head 5 ... Carriage 6 ... Acceleration sensor 7 ... Read / write circuit 8 ... Write inhibit circuit

Claims (2)

[Claims] 1. Head supporting means for supporting a head for writing and reading data to and from a disk, and acceleration detecting means for detecting an acceleration generated by a force applied to the head supporting means. And a control means for prohibiting the write operation of data to the disk by the head when the acceleration of the head support means detected by the acceleration detection means exceeds a predetermined acceleration. apparatus. 2. The disk device according to claim 1, wherein the predetermined acceleration is an acceleration within a range in which a write operation of writing data on a target track by the head is guaranteed.