JPH0743912B2 - Magnetic disk drive having cleaning seek function - Google Patents

Description

Description: (a) Technical Field of the Invention The present invention relates to a magnetic disk device having a cleaning seek function for cleaning the magnetic disk by continuously moving the magnetic head on the magnetic disk.

(B) Background of technology A magnetic head for a magnetic disk device is often of a floating type. The gap between the recording medium and the floating magnetic head is the hydrodynamic levitation force exerted on the slider of the magnetic head by the air flow that flows with the rotation of the magnetic disk, and the force of the boss that presses the magnetic head against the recording medium. It is determined by the balance between and, and this value is about several μm to several 1 μm.

Therefore, adhesion of foreign matter and entry of dust on the magnetic disk surface have a great influence on the reliability of the apparatus, and therefore various countermeasures are taken. However, in addition to the causes of these foreign substances adhering and the ingress of dust, scratches on the magnetic disk surface may cause a signal level drop and a data error due to an extra pulse. In addition to cleaning foreign matter and dust on the magnetic disk surface, detecting errors due to scratches on the magnetic disk surface and immediately analyzing the cause of the detected error, if possible, it is possible to eliminate the cause. It is necessary to secure the above, and the development of effective methods related to these is required.

(C) Prior art and problems Usually, in order to prevent foreign matter from adhering to the magnetic disk surface and intrusion of dust, the circumference of the magnetic disk is tightly sealed, and the inside of the magnetic disk is protected by a high-precision air filter to remove dust. There is a device that performs a positioning operation for cleaning the magnetic head to remove dust adhering to the magnetic disk while the filtered air is constantly being sent.

This cleaning operation only performs the operation of sequentially positioning the magnetic head in each cylinder before performing the recording / reproducing operation of the data on the magnetic disk up to the innermost. Due to this movement of the magnetic head, foreign matter and dust adhering to the magnetic disk collide with the magnetic head due to the rotation of the magnetic disk and are separated, and are blown away by the airflow generated as the magnetic disk rotates. However, there is a drawback that errors in the servo data due to scratches on the servo surface recording servo data for controlling the position of the magnetic head on the magnetic disk surface cannot be detected and removed.

(D) Object of the Invention An object of the present invention is to provide a novel magnetic disk device that solves the above-mentioned drawbacks, and in particular, data (servo data) due to scratches on the surface of the magnetic disk during cleaning operation of the magnetic disk. It is also possible to detect the error of.

(E) Configuration of the Invention The present invention is a magnetic disk device having a cleaning seek function for continuously moving a read head on a rotating magnetic disk to clean the magnetic disk. Detecting means for sending out a signal for suspending the cleaning seek, and for suspending the cleaning based on the signal from the checking means, and based on the signal for restarting the cleaning seek inputted from the outside. This is achieved by a magnetic disk device having a cleaning seek function, which comprises: a cleaning seek control means for restarting the cleaning seek.

(F) Embodiments of the Invention The present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a cleaning control circuit section in a magnetic disk device according to the present invention.

In the figure, 1 is a cleaning control circuit unit, 2 is a status check circuit unit, 3 is a positioning circuit unit, 4 and 5 are flip-flop circuits, 6 is an AND circuit, and 7 is a cleaning control circuit.

In this embodiment, the flip-flop circuits 4 and 5, the AND circuit 6,
A cleaning control circuit 7 configured to include a cleaning control circuit 7, which receives a signal from a higher-level device (not shown) and outputs a cleaning control signal to the positioning circuit unit 3, checks the internal state of the magnetic disk device (status), and checks the data. And a status check circuit unit 2 for holding the status and reporting the status to the host device, a positioning circuit unit 3 for instructing a positioning operation for positioning the magnetic head at a specified position, and a set servo check signal. A flip-flop circuit 4 that changes the state of the output signal (ON signal) output to the AND circuit 6 (input from the status check circuit unit 2) to the OFF signal by the check reset signal from the host device, from the host device The ON signal state is output to the AND circuit 6 by the check enable signal of An input signal from the AND circuit 6 and a AND circuit 6 for ANDing the signals input from the flip-flop circuit 4 and the flip-flop circuit 4 and outputting the result to the cleaning control circuit 7. The cleaning control circuit 7 outputs a control signal to the positioning circuit unit 3 to stop or restart the cleaning positioning operation.

In the present embodiment, the data of the servo surface of each cylinder is read at the same time as the cleaning positioning operation by a command or setting from the host device (a circuit for reading data is not shown). At that time, the command from the host device is used. Check enable signal is flip-flop circuit 5
It has been latched to. At this time, if an error (including an error due to a flaw or the like) is found in the data read from the servo surface of each cylinder, the servo check signal from the status check circuit unit 2 is turned on and the servo check signal is latched by the flip-flop circuit 4. It At this time, the AND circuit 6 calculates the logical product of the two input signals from the flip-flop circuit 4 and the flip-flop circuit 5 and outputs it to the cleaning control circuit 7 as an ON signal for temporarily stopping the cleaning positioning operation. Cleaning control circuit 7
Receives a signal from the AND circuit 6 to temporarily stop the cleaning positioning operation.

Next, when the error content of the servo surface is analyzed (visual inspection, etc.) and the operation is ended and the cleaning positioning operation is continued, a check reset signal is input to the flip-flop circuit 4 by a command from the host device as well. The output of the flip-flop circuit 4 changes to an off signal, and the state is ANDed by the AND circuit 6 to output the signal for temporarily stopping the cleaning positioning operation, which is output to the cleaning control circuit 7, to OFF. The cleaning control circuit 7 releases the suspension of the cleaning positioning operation by the OFF signal from the AND circuit 6 and restarts the cleaning positioning operation.

(G) Effect of the Invention According to the present invention, when an error is detected by reading the servo data of each cylinder during cleaning of the magnetic disk, it has a function of temporarily stopping the cleaning operation of the magnetic disk. The contents of the error can be analyzed immediately, and the magnetic disk surface can be judged as good or bad, and if possible, the defective part can be repaired. Further, after the judgment of good / bad of the magnetic disk, the cleaning operation can be restarted from the position where it was temporarily stopped, so that there is an effect that the good / bad inspection of the servo surface of the magnetic disk can be carried out efficiently.

[Brief description of drawings]

FIG. 1 shows an embodiment of a cleaning control circuit in a magnetic disk device according to the present invention. In the figure, 1 is a cleaning control circuit unit, 2 is a status check circuit unit, 3 is a positioning circuit unit, 4 and 5 are flip-flop circuits, 6 is an AND circuit, and 7 is a cleaning control circuit.

Claims (1)

[Claims] 1. A magnetic disk device having a cleaning seek function for continuously moving a read head on a rotating magnetic disk to clean the magnetic disk, and detecting an abnormality of a read signal from the read head. Checking means for transmitting a signal for temporarily stopping the cleaning seek, and the cleaning is temporarily stopped based on a signal from the checking means, and the cleaning seek is restarted based on a signal for restarting the cleaning seek input from the outside. A magnetic disk device having a cleaning seek function, comprising: a cleaning seek control means.