JPS61182681A - Maintenance method of flexible disk device - Google Patents

Abstract

PURPOSE:To diagnose a device without requiring special devices by rewriting a portion of data written into a maintenance disk by the magnetic head of a flexible disk device and comparing the two data reproduced by the head. CONSTITUTION:By using the same format as that used in performing the usual information recording, the information is recorded in each recording sector of the recording track. A part of the records such as odd-numbered sector of a maintenance disk 12 is rewritten by the magnetic head 11 of a flexible disk device to be maintained. The rewritten odd-numbered sector data and the even-numbered sector data not rewritten are reproduced by the head 11. An integrating circuit 14 is controlled through a demodulator 18, a data circuit 19, a control circuit 20 and so forth and the reproducing data of each odd- and even-sector is processed by a circuit 14 and the results of integration are accumulated in a memory 15. Based on the contents of the memory 15, a computing circuit 16 compares the amplitudes of the two reproduced waveforms and the positional deviation of the magnetic head is easily and surely diagnosed without requiring special devices.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a flexible disk device maintenance method suitable for maintaining a flexible disk device installed in a system.

[Background of the invention]

Conventional maintenance disks, as described in Japanese Patent Publication No. 59-7142, are mainly used to determine the position of the magnetic head of a flexible disk device using dimensional values and to find out how much it has deviated from a predetermined position. It is being For this reason, in the conventional maintenance method for a 7 flexible disk device, a special signal pattern as shown in FIG. The magnetic head position was measured from the signal amplitudes VA and VB as shown in the figure.

However, the conventional maintenance method for flexible disk devices described above requires a special device as a measuring device.
There is a problem in that it is extremely inappropriate for general users to judge whether the flexible disk device installed in the system is normal or abnormal.

[Purpose of the invention]

The present invention has been made in view of the problems of the prior art described above, and provides a method for maintaining a flexible disk device that can diagnose a flexible disk device installed in a system without requiring any special equipment. is intended to provide.

[Summary of the invention]

The maintenance method for a flexible disk device of the present invention uses an accurately positioned magnetic head to write data on the recording track of a maintenance disk in the same format as when performing normal information recording, and then A part of the data written on the storage disk is rewritten using the magnetic head of the flexible disk device to be maintained, and the rewritten data and the unrewritten data are reproduced using the magnetic head of the flexible disk device to be maintained. , the amount of deviation of the magnetic head of the flexible disk drive to be maintained is detected by comparing the amplitudes of both reproduced wave signals.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in more detail with reference to embodiments shown in the accompanying drawings.

FIG. 1 shows one of a plurality of concentric recording tracks provided on a maintenance disk developed in a straight line. Like a normal information recording disc, it has a plurality of division positions called sectors 0 to (N-t) on the recording track, and sector t has an ID section indicating an occupied position further on one round. It consists of a data section where information is actually written and gaps between sectors. In addition, in front of the ID section and data section, there is a variable frequency oscillator circuit (CVFO circuit).
It has a PLL 5YNC section that operates the 1.1 data, and has an address mark (indicated by AM in the figure) immediately before the 1.1 data. Furthermore, as shown in the figure, a gap G1 area is provided between the starting point on the recording track and the first sector O, and a gap G1 is provided between the last sector (N-1) and the end point on the recording track. There is a G4 area. In this way, by arranging the recording tracks in exactly the same way as on the information recording disk, it is possible to read out the contents of the data section of the maintenance disk even when the system is installed.

Next, a second
This will be explained using figures.

FIG. 2, like FIG. 7, shows arbitrary recording tracks of the maintenance disk developed in a straight line. First, in manufacturing maintenance disks, it is necessary to have highly precisely aligned magnetic heads that write to every device track at its predetermined radial location. That is, the second
The physical center line of the track to be measured shown in the figure is centered with respect to the effective track width W magnetized by the magnetic head, and the distance from the center of the spindle that rotates the disk is very precisely aligned with the specified value. It is necessary that the

For example, when the track pitch is about 265 μm, the allowable radial position error for the magnetic head is about ±50 μm, so an accuracy of ±5 μm or less is required for the ideal value. With such precision, the state of the magnetized recording track of the maintenance disk that has been written continuously for -3 cycles is determined as follows:
Sector 0 and sector 2Vc are shown in the figure. Here, the recording track is composed of a plurality of sectors as described above.

Next, this maintenance disk is inserted into the flexible disk device to be maintained, and the data portion of every other sector 0 to (N-1) is rewritten using the magnetic head of the flexible disk device to be maintained. Sector 1 shown in FIG.
The data section 6 shows an example of a data section that has been rewritten using the magnetic head of the flexible disk device to be maintained, and is an example of the data section of sectors 0 and 2 that has maintained the state at the time of manufacturing the maintenance disk. It is different from the magnetization position. That is, both sides of the data portion of sector 1.3 are erased by the tunnel erase head, and the magnetization position of the data portion of sectors 1 and 5 is determined by the position of passage of the magnetic head of the flexible disk device to be measured.

FIG. 5 is a diagram showing a reproduced waveform signal obtained by reproducing the recording track shown in FIG. 2 with the magnetic head of the flexible disk device to be maintained.

Among the amplitudes of this reproduced waveform signal, the amplitudes of the rewritten data part V, , V, and the amplitudes of the unrewritten data part V
. By comparing h''2, the radial deviation amount Δ of the magnetic head of the flexible disk drive to be measured can be confirmed using equation (1).

However, Δ: Amount of radial deviation of the magnetic head v,: Amplitude of the rewritten data section vo: Amplitude of the unrewritten data section W: Track width of the magnetic head. This disc uses the same recording format as a normal information recording disc. Therefore, the data section is read by the flexible disk device to be maintained, and in addition to reading the data section that has been rewritten such as sectors 1 and 5, the data section that was written at the time of manufacturing the maintenance disk, such as sector 0.2, is read. The problem in diagnosis is whether or not it is possible to read the data. This is because it is natural that the data portion rewritten using the magnetic head of the flexible disk device to be maintained can be read by the flexible disk device to be maintained. The above diagnosis can be performed by observing the waveform using, for example, an oscilloscope.

Next, it is also possible to find the amplitude of the average value signal of the reproduced waveform signal of the data section and find the amount of deviation of the magnetic head. FIG. 4 is a diagram showing an example of a measurement circuit used for diagnosing such a flexible disk device to be maintained. In the figure, a reproduced waveform signal from a magnetic head 11 that reproduces a maintenance disk 12 is sent to a demodulation circuit 18 via an amplifier 15, and then transferred to a data discrimination circuit 19 as a digital signal. On the other hand, the output of the amplifier 13 is input to an integrating circuit 14, and the signal amplitude of the data portion is detected. This integrating path 14 is connected to the read command signal of the control circuit section 20 and the address mark (A) immediately before the data section.
M) Operates based on the logical sum of detection signals. That is, the read command signal is terminated when the control circuit section 20 recognizes the CRC code indicating that the data section has ended. At this point, the integrating circuit 14 transfers the integrated voltage (proportional to the average voltage of the data section) to the memory 15. Therefore, after securing a memory area equal to the number of data parts on one revolution of the disk and storing the integrated voltage of each data part,
The amount of deviation of the magnetic head is calculated by the arithmetic circuit 16 from the integrated voltage of the rewritten data section and the integrated voltage of the data section that is not rewritten. Furthermore, the arithmetic circuit 1
6 averages the amount of deviation of a plurality of magnetic heads over the circumference of the recording track, and detects the deviation fL- (average value) of the magnetic head 11 of the flexible disk device to be maintained. The determination circuit 17 determines whether the amount of deviation (average value) thus detected is an appropriate value. Figure 5 explains the above operation corresponding to the recording format, and shows that the integrating circuit voltage V
i corresponds to the above-mentioned vo-vN-1.

Although not mentioned in the above explanation, in order to compare the average signal voltage of the data part, it is preferable that the data patterns before and after rewriting are the same in order to eliminate errors caused by signal resolution.

Further, the number of divided sectors on the circumference of the recording track does not necessarily have to be an even number, as long as the signals of a set of data portions before and after rewriting can be compared at two nearby locations on the circumference. However, in order to reduce errors depending on the magnetic characteristics of the disk, the average value of the amount of deviation described above is the best method.

〔Effect of the invention〕

According to the present invention, the following effects can be obtained.

(1) Determining the amount of positional deviation of the magnetic head of a flexible disk drive to be maintained installed in the system using an oscilloscope or a simple and inexpensive measurement circuit added to the system, without requiring special measuring equipment. I can do it.

(2) Furthermore, the overall characteristics of the flexible disk device to be maintained, including the magnetic head, can be easily determined.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of the format of the maintenance disk used in the present invention, FIG. 2 is a diagram showing the magnetization pattern of each sector shown in FIG. 1, and FIG. 3 is a diagram showing the magnetization pattern of each sector shown in FIG. FIG. 4 is a waveform diagram showing an example of a measurement circuit installed in the system. FIG. 5 is a waveform diagram showing the operation of the measurement circuit shown in FIG. 4. FIG. 6 is a waveform diagram showing the operation of the measurement circuit shown in FIG. 4. The magnetization pattern of the maintenance disk, FIG. 7 is a diagram showing a reproduced waveform signal of the magnetization pattern shown in FIG. 6. 11...Magnetic head, +2...Maintenance disk, 1
5... Amplifier, 14... Integrating circuit, 15... Memory, 16... Arithmetic circuit, 17... Judgment circuit, 18...
...Demodulation circuit, 19...day 1st paper 3rd drawing 5th picture 4th stuttering of scratches L
vikuru figure

Claims (1)

[Claims] Using an accurately positioned magnetic head, data is written to the recording track of the maintenance disk in the same format as when recording normal information, and then a portion of the data written to the maintenance disk is Rewriting using the magnetic head of the flexible disk device to be maintained, reproducing the rewritten data and unrewritten data using the magnetic head of the flexible disk device to be maintained, and comparing the amplitudes of both reproduced waveform signals. 1. A method for maintaining a flexible disk device, comprising: detecting the amount of deviation of a magnetic head of a flexible disk device to be maintained.