JPH04221401A - Magnetic disc device - Google Patents

Abstract

PURPOSE:To detect head crush by a method wherein a mechanism which senses collision or contact between a magnetic head and a magnetic disc and error information is outputted in accordance with the sensing signal. CONSTITUTION:When a magnetic disc 8 is made to rotate, sliders 71 and 76 make a magnetic head 7 float from the magnetic disc 8 surface with a pneumatic pressure. If the head 7 collides or comes into contact with the disc 8 at that time, a piezoelectric device 72 attached to the head 7 outputs an electric signal and supplies the signal to a detecting circuit 8. The circuit 12 converts the supplied electric signal and supplies the converted output to an error controller 11. The controller 11 transmits the supplied signal immediately to a magnetic disc processor 2 as error information. Then the processor 2 transmits the error information to a CPU 1 to detect head crush.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive.

0002

2. Description of the Related Art Conventionally, a magnetic disk device has a magnetic disk processing device 2 connected between a CPU 1 and a magnetic disk device 30, as shown in FIG. Commands from the CPU 1 are transmitted to the magnetic disk processing device 2 and further transmitted to the magnetic disk device 30. The magnetic disk device 30 includes a device control section 4 connected to the magnetic disk processing device 2, a write control section 5, a write amplifier 6, and a magnetic head 7.
0, a magnetic disk 8, a read amplifier 9, a read control section 10, and an error control section 110.

[0003] When the command of the CPU 1 is writing, data flows through the CPU 1, the magnetic disk processing device 2, the device control section 4, the write control section 5, the write amplifier 6, the magnetic head 70, and the magnetic disk 8 in this order. If any error occurs during the process, the flow of error information is transmitted to the write control section 5, error control section 110, device control section 4, magnetic disk processing device 2, and CPU 1 in this order.

Next, when the instruction of CPU1 is reading,
The data flow is sequentially carried out by the magnetic disk 8 and the magnetic head 70.
, the read amplifier 9, the read control section 10, the device control section 4, the magnetic disk processing device 2, and the CPU 1. If any error occurs during the process, the flow of error information is transmitted to the read control section 10, device control section 4, magnetic disk processing device 2, and CPU 1 in this order.

[0005]

[Problems to be Solved by the Invention] The conventional magnetic disk drive described above does not have a mechanism for detecting head crashes due to collision or contact between the magnetic head and the magnetic disk, so it is impossible to detect the occurrence of a head crash. There were drawbacks.

An object of the present invention is to provide a magnetic disk device that detects the occurrence of a head crash.

[0007]

Means for Solving the Problems In order to achieve the above object, the magnetic disk drive of the present invention includes a head crash detection mechanism that detects collision or contact between a magnetic head and a magnetic disk, and a head crash detection mechanism that detects collision or contact between a magnetic head and a magnetic disk. It has a collision detection circuit that outputs an error signal based on an electrical signal, and an error control section that receives the error signal from the collision detection circuit and outputs error information.

[0008] Furthermore, the head crash detection mechanism includes:
It is made up of piezoelectric elements.

Further, the piezoelectric element is integrated into the magnetic head and converts the impact force generated when the magnetic head and the magnetic disk collide or come into contact into an electrical signal and outputs it.

0010

[Operation] The piezoelectric element 72 senses the collision or contact between the magnetic head and the magnetic disk and outputs an electric signal. The collision detection circuit 12 receives the output signal of the piezoelectric element 72 and outputs an error signal, and the error control section 11 outputs error information, that is, information that a head crash has occurred, based on the error signal.

[0011]

Embodiments Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing one embodiment of a magnetic head used in a magnetic disk device of the present invention. In the figure, the magnetic head 7 includes a planar slider 71, a tapered slider 76, a piezoelectric element 72, a thin film head 73, a thin film head 75, and a lead wire 74.

The slider 71 and the slider 76 are used to levitate the magnetic head 7 from the surface of the magnetic disk by air pressure when the magnetic disk rotates. The piezoelectric element 72 converts the collision or contact of the magnetic head 7 with the magnetic disk surface into an electrical signal. Thin film head 73
The thin film head 75 records and reproduces data. The lead wire 74 connects the thin film head 73 and the thin film head 75 and the electrical signals of the piezoelectric element 72 to each circuit of the magnetic disk device.

FIG. 2 is a block diagram showing an embodiment of a magnetic disk device according to the present invention. The magnetic head 7 shown in FIG. 1 is used as the magnetic head 7 of this magnetic disk device. Furthermore, compared to the conventional magnetic disk drive 30 shown in FIG. 3, the magnetic head and error control section are changed to a magnetic head 7 and an error control section 11, respectively, and a collision detection circuit 12 is connected between them.

When the magnetic head 7 collides with or comes into contact with the magnetic disk, the magnetic head 7 outputs an electrical signal and inputs it to the collision detection circuit 12 . The collision detection circuit 12 converts the input electric signal (for example, using a level converter, etc.) and inputs the output to the error control section 11 . Error control section 1
1 is immediately sent to the magnetic disk processing device 2 as error information.
Communicate to. The magnetic disk processing device 2 transmits error information to the CPU 1.

[0015]

[Effects of the Invention] As explained above, in the present invention, a magnetic disk device is equipped with a head crash detection mechanism.
This has the effect of being able to detect the occurrence of a head crash.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of a magnetic head used in a magnetic disk device of the present invention.

FIG. 2 is a block diagram showing an embodiment of the magnetic disk device of the present invention.

FIG. 3 is a block diagram of a circuit that performs reading and writing of a magnetic disk device in a conventional magnetic disk device.

[Explanation of symbols]

1 CPU 2,30 Magnetic disk processing device 3 Magnetic disk device 4 Device control section 5 Write control section 6 Write amplifier 7,70 Magnetic head 8 Magnetic disk 9 Readout amplifier 10 Read control section 11,110 Error control section 12 Collision detection circuit 71 Slider (plane) 72 Piezoelectric element 73, 75 Thin film head 74 Lead wire 76 Slider (taper)

Claims (3)

[Claims] Claim 1: Collision between a magnetic head and a magnetic disk;
or a head crash detection mechanism that senses contact, a collision detection circuit that outputs an error signal based on the electrical signal from the head crash detection mechanism, and an error control unit that receives the error signal from the collision detection circuit and outputs error information. A magnetic disk device comprising: 2. The magnetic disk device according to claim 1, wherein the head crash detection mechanism is composed of a piezoelectric element. 3. The piezoelectric element is integrally incorporated in the magnetic head, and converts and outputs an impact force generated when the magnetic head collides with or contacts the magnetic disk into an electrical signal. , 2.