JPH03268276A - Medium defect inspecting instrument - Google Patents

Abstract

PURPOSE:To unnecessitate the waiting of one revolution for performing the read-out of test data by writing the test data in a recording medium by switching an index signal synchronizing with the rotation of a rotary recording medium and a delayed index signal, and detecting the defect of the recording medium by reading out it. CONSTITUTION:The index signal 10 synchronizing with the rotation of the rotary recording medium from a storage device 1 and the delayed index signal 13 through an index delay circuit 3 are switched by a switching circuit 4. The gate of a write-in control circuit 5 is controlled by this signal 10, and the test data 14 from a host device becomes write data 12, and is written in a storage medium, and this data is read out from the storage medium by the next signal 10, and the defect of the storage medium is detected by a medium defect detection circuit 6. The detection of the defect is executed similarly for a next track as well by using the signal 13. Accordingly, the rotation waiting of one revolution portion of the recording medium for perform the read-out of a test pattern becomes unnecessary, and time required for detecting the defect can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a medium defect inspection apparatus, and more particularly to a medium defect inspection apparatus having an index signal delay circuit.

[Conventional technology]

Conventionally, a medium defect inspection device for a storage medium used in a rotating storage device (hereinafter referred to as the device) detects a certain dropout or drop in the playback signal of data written to the storage medium at the highest possible operating frequency of the device. An analog test method that compares the test data with equipment inspection reference values to determine defects, and a digital test method in which specific test data is written to a storage medium and the digital signal pattern is read out through a discrimination circuit inside the equipment. - There is a digital test method that compares signal patterns and identifies defects, and both methods typically use several types of test data to improve inspection accuracy.

[Problem to be solved by the invention]

As shown in FIG. 3, the conventional medium defect inspection apparatus described above uses an index signal 20 indicating the starting point of a data track, which is sent out at a period T in synchronization with the rotation of the storage medium from a device equipped with the storage medium to be inspected. The test data (test data) -21 of the medium defect inspection device is turned on and off in synchronization with A processing time t4 is required as shown in software processing 22, including software processing for detecting free time and medium defects. Therefore, test data is written to the storage medium using the first index signal, software processing for detecting medium defects is performed using the next index signal, and test data is read using the next index signal. That is, in order to read the test data, a rotation waiting time equivalent to one revolution of the storage medium is required. Therefore, for example, when two types of test data are used, eight cycles are required, and there is a drawback that it takes a long time to inspect all the tracks of one storage medium. In addition, if the test gate is turned off before the index signal in order to eliminate this rotation waiting time, the software processing time is t.
This method has the drawback that an undetected error portion occurs on the track of the storage medium for a time corresponding to 3.3 seconds, making it difficult to improve the efficiency of inspection.

[Means to solve the problem]

The present invention provides a medium defect inspection method that detects defects existing on data tracks of the storage medium by writing test data on a storage medium used in a rotating storage device, and reading and comparing the test data. In the apparatus, a delay circuit delays an index signal synchronized with rotation of the storage medium sent from the rotary storage device by a predetermined time, and switches between the index signal and the delayed index signal output from the delay circuit. a switching circuit that outputs, a write control circuit that inputs the output signal of the switching circuit and the test pattern sent from the upper circuit and sends the test data to the rotary storage device;
medium defect detection means for detecting defects in the storage medium by inputting the output signal of the switching circuit and the test data read from the rotary storage device, and outputting error information to the upper circuit. It is characterized by:

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the medium defect inspection apparatus of the present invention. In FIG. 1, the media defect inspection bag W2
is the index delay circuit 3. Switching port 284. Write control circuit 5. Consisting of a medium defect detection circuit 6 and an error position memory circuit, an index signal 10 sent from a storage device 1 equipped with a storage medium to be inspected is connected to an index delay circuit 3 and a switching circuit 4 via a signal line, and the switching circuit 4
The output of is connected to the write control diagram &jfr5 and the medium defect detection circuit 6. The write control circuit 5 is connected to a signal line for sending test data 14 from the upper circuit and a signal line for sending the output of the switching circuit, and is further connected to a signal line for sending write data 12 to the memory bag W1. . The medium defect detection circuit 6 also receives a read signal 1 from the storage device 1.
1, and is also connected to the error position memory circuit 7, and the output line is connected to the upper circuit.

Next, the operation of this embodiment will be explained. FIG. 2 is a timing chart showing the operation of the medium defect inspection apparatus of this embodiment. In this embodiment, a case will be explained in which two types of test data are used. First, when a test start command is issued from the upper circuit, the switching circuit 4 selects the index signal 10 with a period T synchronized with the rotation of the storage medium sent out from the storage device 1, and the write control circuit is synchronized with the index signal 10. Then, test gate 16 is turned on, test data 14 is sent to storage device 1 as write data 12, and data A is written to the storage medium to be tested mounted in storage device 1. This test game 1
~ is the same as the conventional embodiment, in order to correctly detect the start code of data, there is an empty time of about 10 bytes immediately before the data, and the processing time required for detecting a medium defect in the medium defect detection circuit 6, so-called software processing. In order to provide a margin for 9 or more, the time during which the test gate 16 is turned on after the index signal is set in advance to time t2. Next, predetermined software processing (processing time ts
) is performed, the medium defect detection circuit 6 immediately turns on the test game () with the second index signal, performs a read operation of data A which is the test data from the storage device 1, and outputs the read signal. 11 is determined. If an error is detected therein, information regarding the position of the error occurrence and the length of the error in the track to be inspected is stored in the error position memory circuit 7 using the index signal as a starting point, and from the error position memory circuit 7 to the upper level circuit. Report to.

Subsequently, the switching circuit 4 passes the index signal 10 through the index delay circuit 3 and selects the third delayed index signal 13 which is delayed by a time t. and test gate 21. The software processing 22 is performed at a timing delayed by the time t1 from the above, and the write control circuit 5 writes data 12 to the memory bag N1.
At the same time, the fourth delayed index signal 13 is used to read test data from the storage device 1 in the medium defect detection circuit 6, and the contents of the read signal 11 are determined.

Note that the period T1 time 1. ．． 12 and t are respectively t,
The relationship is ≧T t 2 > t 3.

〔Effect of the invention〕

As explained above, according to the medium defect inspection device of the present invention, by alternately switching the timing of the test gate using a plurality of test data, mutually undetected portions on the tracks of the storage medium can be compensated for. Therefore, there is no need to wait for one rotation of the storage medium to read the test data, and for example, when two types of test data are used, it is possible to perform the inspection in four cycles. Therefore, it is possible to inspect all the tracks of the storage medium in a short time, so that it is possible to provide a medium defect inspection apparatus with high inspection efficiency.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the medium defect inspection apparatus of the present invention, FIG. 2 is a timing chart showing the operation of the medium defect inspection apparatus of this embodiment, and FIG. 3 is a medium of a conventional embodiment. 5 is a timing chart showing the operation of the defect inspection device. 1...Storage device, 2...Media defect inspection device, 3...
・Index delay circuit, 4... switching circuit, 5...
Write control circuit, 6... Medium defect detection circuit, 7...
Error position memory circuit, 10. 20... Index signal, 11... Read signal, 12... Write data, 13... Delayed index signal, 14...
・Test data, 15...Error information, 16.21
...Test gate, 17.22...Software processing.

Claims (1)

[Claims] In a medium defect inspection device that detects defects existing on data tracks of the storage medium by writing test data on a storage medium used in a rotating storage device and reading and comparing the test data, the a delay circuit that delays an index signal synchronized with the rotation of the storage medium sent out from the rotary storage device by a predetermined time; and a switching circuit that switches and outputs the index signal and the delayed index signal output from the delay circuit. a write control circuit that inputs the output signal of the switching circuit and the test pattern sent from the host circuit and sends test data to the rotating storage device; and the output signal of the switching circuit and the rotating storage device. A medium defect inspection device comprising: medium defect detection means for inputting the test data read from the device, detecting defects in the storage medium, and outputting error information to the upper circuit.