JPH03238621A - Magnetic disk testing system for magnetic disk certifier - Google Patents

Abstract

PURPOSE:To simplify a circuit by connecting two pieces of magnetic heads for the outer circumferential area and the inner circumferential area of the halved range of a recording medium alternately to a common set of a write-in control circuit and an error detection circuit by switching them by a test controller controlled by a microprocessor. CONSTITUTION:The range of the recording medium of a magnetic disk 1 is halved into the outer circumferential area 1a and the inner circumferential area 1b, and the recording medium is inspected by seeking a track and writing in and reading out a test signal for every area by using two pieces of the magnetic heads 2a provided for each area. A set of the write-in control circuit 2e and the error detection circuit 2f common for each area is provided, and the magnetic head 2a of each area is switched to the write-in control circuit 2e and the error detection circuit 2f by the test controller 3a controlled by the microprocessor 3. Thus, the write-in control circuit and the error detection circuit having been considered to be required by two sets in the past can be saved into one set, and simultaneously, a test can be executed in the same test duration as in the past, and it can contribute to the simplification of a magnetic disk certifier.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a magnetic disk test method for a magnetic disk certifier.

[Prior Art] Magnetic disks, which are frequently used as information recording media, are
During the production process, the quality of the recording medium is inspected using a magnetic disk certifier. During inspection, a test signal of an appropriate frequency is written, and it is read out to detect errors such as missing codes (MIS) and EXT), and to detect fluctuations in the peak value of the test signal (MOD).
) is measured. Since these tests are performed for each of the many tracks provided on the disk, the tests require a considerable amount of time. On the other hand, in order to shorten inspection time and improve inspection efficiency, the recording medium surface of the disk is divided into two areas, an outer circumferential area and an inner circumferential area, and two sets of magnetic heads and necessary circuits are installed for each area. A method of simultaneously testing is being used.

FIGS. 2(a), (b), and (c) illustrate the above-mentioned two-part type magnetic disk certifier.
In Figure (a), the recording medium of a magnetic disk 1 to be inspected is divided into two areas, an outer circumferential area 1a and an inner circumferential area ib, and a testing section 2-1, 2-2 is provided for each area. The magnetic heads (HDl) 2a-1 and (HD2) 2a-2- of each inspection section scan the tracks within the outer circumferential area la and inner circumferential area lb using their respective carrier machines lateral 2b-1 and 2b-2. - to do. For each magnetic head, write amplifiers 2cm1, 2c2, read amplifiers 2d-1, 2d-
2, δ input control circuit 2 e-1+2 e-2, and error detection circuit 2f-12f-2 are connected to each other. For these, a test controller 3a controlled by a microprocessor 3 is provided, and an index (INDEX) signal indicating the starting point of the disk circumference from an index detection sensor that does not return to the controller is manually inputted to each part. Given the necessary control signals, Figure (c)
The inspection is performed according to the sequence shown in . In the diagram (C), the sequences on the magnetic heads HDl side and HD2 side have the same processing content and the same phase, and the following processing is performed on both sides at each time of the manually input INDEX signal. First, a track is sought, and a test signal is written by the write control circuit 2e for one round of this track.

Then, for one round of this track, the error detection circuit 2
The above-mentioned inspection items are inspected by f.

Figure TAA/! In determining If, the peak value of the test signal is detected and the average value thereof is calculated by the microprocessor 3. A test for MIS errors and a MOD test for the peak value of the test signal are performed using the calculated average value as a reference, and when these are completed, the test signal is erased in the next round and an EXT error is tested. The above inspection of one track is completed after five revolutions of the disk, transparent seeking is performed to the next track, the above test sequence is executed, and all tracks are inspected.

[Problem to be Solved] In the above inspection, since the area of the recording medium is divided into two, it is very effective to shorten the inspection time.

Two sets of δ writing control circuits 2 are provided for each HD2.
e-1, 2e-2 and error detection circuits 2f-1, 2f-
2, the disadvantage is that the number of circuits increases. Therefore, it is desired to simplify the device by commonly using these as a set.

This invention has been made in view of the above, and it is possible to simplify the circuit by commonly using one set of a write control circuit and an error detection circuit in a magnetic disk certifier that divides the area of a recording medium into two. The purpose is to provide a test method.

"One step to solve the problem" This invention divides the range of a magnetic disk recording medium into two areas, an outer area and an inner area, and uses two magnetic heads provided for each area to This is a test method for magnetic disk certifiers that inspects the recording medium by seeking tracks and reading/reading test signals for each area.It uses a set of old control circuits and error detection common to each area. A circuit is provided, and a test controller controlled by a microprocessor switches the magnetic field of each area to the a write control circuit and the error detection circuit. In addition, the phases of the test blocks for each area are set by one revolution of the magnetic disk, and the tests of writing test signals, reading test signals, and writing test signals are performed on consecutive tracks for each rotation of the magnetic disk. Erasing the test signal and performing an extra error test on the erased track are performed alternately.

[Effect] In the above test method, the two magnetic nodes for the outer circumferential area and the inner circumferential area, which divide the range of the recording medium into two, are switched by a test controller controlled by a microprosensor and co-flex. They are alternately connected to one set of δ input control circuit and error detection circuit. The phase of the test sequence for each area is shifted by one revolution of the magnetic disk, and the track seek, 8-write test signal, test signal read test, test signal erase, and extra error test for erased tracks are performed. are performed alternately.

[Embodiment 1] Figures (a) and (b) show the circuit configuration and test sequence in an embodiment of the magnetic disk certifier test method according to the present invention. In figure (a),
The recording medium of the magnetic disk is divided into two areas, one in the outer area and one in the inner area.
For each area, magnetic heads HDt, HD
2 are correspondingly provided, and each light amplifier 2 c
-1+2c-2 and lead amplifier 2d-1,
The connection to 2d-2 is shown in Figure 2(b) above.
It is similar to In contrast, one set of δ-input control circuit 2
e and error detection circuit 2f.

and switches SWI 3b-1 and 5W23b-2 are provided. The test controller 3a is controlled by the microprocessor 3, and the switches sw, , SW, 2 are switched by this and the input INDEX signal, and a test sequence for each magnetic head HD1+HD2 is executed. In Figure (C), the phase of each test sequence is one rotation of the magnetic disk (each IND
EX signals) are shifted. First, a track in the outer peripheral area is sought, and a test signal outputted from the write control circuit 2e is written to the track by the HD.

Here, the solid line and dotted line in the figure indicate the switching timing of each switch SWI and SW2 by the INDEX signal. By this switching, the test signal of the outer peripheral area read by HDl is manually input to the error detection circuit 2f for TAA measurement (track Measurement of the average value of peak values for one round), MI
S and MOD tests are performed, and at the same time test signals are written to the tracks in the inner circumferential area by the HD 2. When this is finished, each switch is switched again, and the test signal for the track in the outer area or HDr is erased, and the TAA signal for the track in the inner area is erased.
Measurements and MIS and MOD tests are performed. Then each switch is changed and the EX of the track in the outer area is changed.
The T test was done and the test of the track in the outer area was 1
go around At the same time, the test signal of the track in the inner area is erased, and furthermore, by changing each switch, the EXT signal is erased.
A test is performed and one test is missed for that track.

Such a test sequence is performed for each track in turn.

[Effects of the Invention] As is clear from the following explanation, according to the test method according to the present invention, the old control circuit and error detection circuit, which were required in the past, are reduced to one set, and the old control circuit and error detection circuit are reduced to one set. 6ft.
Negative (There are some significant effects that contribute to the simplification of the disk certifier.

4. What is the meaning of 4? F. Explanation FIGS. 1(a) and 1(b) show an embodiment of the magnetic disk certifier test method according to the present invention.
A diagram showing the circuit configuration and test sequence, FIG. 2(a),
(b) and (c) are diagrams showing a method of dividing a recording medium area into two in a magnetic disk certifier, a conventional circuit configuration, and a test sequence.

1...Magnetic disk, la...Outer area,
1b...Inner peripheral area, 2...Inspection section, 2a...
・Magnetic nod, 2b... Carriage mechanism, 2C
...Light amplifier, 2d...Read amplifier, 2
e...Write control circuit, 2f...Error detection circuit, 3...Microprocessor, 3a...Test controller, 3b...Switch.

Claims (1)

[Claims] (1) The range of the recording medium of the magnetic disk is divided into two areas, an outer area and an inner area, and two areas are provided for each area.
In a magnetic disk certifier that tests the recording medium by writing/reading test signals in each area using two magnetic heads, a set of write control circuit and error detection circuit common to each area is provided. , a test controller controlled by a microprocessor switches the magnetic head for each area with respect to the write control circuit and error detection circuit;
and the phase of the test sequence for each area is shifted by one rotation of the magnetic disk, and track seeking is performed sequentially for each rotation of the magnetic disk, writing of the test signal, and writing of the written test signal. A magnetic disk test method for a magnetic disk certifier, characterized in that a reading test of the test signal, erasing of the test signal, and an extra error test of the erased track are performed alternately.