JPS6028083A - Off-track detecting method of disk memory - Google Patents

Abstract

PURPOSE:To decide the end detection of positioning with off-track and to simplify the division of faults by shifting an information recording/reproducing device in the direction where a track is crossed and measuring the reading signal and its output level during the shift of said recording/reproducing device. CONSTITUTION:An information recording/reproducing device is shifted in steps in the direction where a track is crossed by a program to read the information to a control circuit which actuates an access function. Then the peak of the reading signal which is supplied to a peak detecting circuit 10 is detected by the signals which are applied selectively from drivers 40-90 respectively and stored in a memory circuit 20. An operator/comparator 30 compares the peak values with each other when an offset action is through and each peak value is stored in the memory 20. Thus off-track/non-off-track signals are obtained.

Description

[Detailed description of the invention] <Detailed description of the invention> The present invention relates to a magnetic disk device and an optical disk device.

This invention relates to a disk storage device such as an optical-magnetic disk device, and is particularly capable of detecting whether or not an information recording/reproducing device such as a magnetic head, an MR head, an optical head, etc. is positioned near a track to be recorded/reproduced. The present invention relates to an off-trunk detection method.

<Technical Background> A disk storage device is generally equipped with a plurality of concentric information tracks (simply referred to as tracks) on a disk-shaped recording medium, and an information storage head, which is generally referred to as a head, is attached to the information track. /Positioning the reproducing device and recording and/or reproducing information.

The disk storage device according to the present invention includes a recording-only disk storage device for recording information, a reproduction-only disk storage device for reproducing information, and an information recording/reproducing disk storage device for recording and reproducing information.

The disk storage device records/records information on the desired trunk.
To position the playback device, servo information is generally, but not always, used for positioning, and once the playback device is positioned at the desired trunk, the information is played back and the track number is determined from the played information. Positioning is completed by reading out the information shown and confirming that the information recording/reproducing device is positioned at the desired trunk.

<Prior Art and Problems> By the way, if the positioning of the information storage/reproducing device with respect to the trunk is not completed, that is, the information cannot be read when reproducing the information to confirm the positioning. In this case, a retry will be made, but
In this retry, the information recording/reproducing device is slightly moved in the direction across the track to reproduce the information again.

If such retry is performed a plurality of times and reproduction is not performed, an error will occur.

However, with conventional methods, it was not possible to determine why the error occurred.

That is, there is a drawback that it is impossible to determine whether the information recording/reproducing device is not actually positioned at the desired trunk, or whether the information recording/reproducing device is positioned but an error occurs due to an abnormality in the reproduction system.

(Objective of the Invention) Therefore, the present invention aims to provide a novel off-track detection method for a disk storage device that eliminates the above-mentioned disadvantages, and particularly aims to provide a new method for detecting off-track in a disk storage device that eliminates the above-mentioned disadvantages. The purpose of this is to determine whether or not it is not detected.

<Structure of the Invention> In order to achieve the above object, the present invention provides a disk storage device that records/reproduces information by selectively positioning an information recording/reproducing device with respect to a plurality of recording tracks, comprising: If the completion of positioning of the information recording/reproducing device to the trunk to be recorded/reproduced cannot be detected, the information recording/reproducing device
When the reproducing device is moved in a direction across the trunk and the read signal obtained at that time increases or decreases, it is detected that the information recording/reproducing device is located at least near the track.

<Embodiments of the Invention> FIG. 1 shows a diagram for explaining the off-track phenomenon according to the present invention, and FIG. This shows the readout signal waveform.

In Fig. 1, 1.2 indicates tracks (also called cylinders) on the recording medium, and 3 a - d indicate information recording/
3A and 3B show a state in which the information recording/playback device is on-track to the trunk/or 2, and 3c and 3d show a state in which it is off-trunk.

In particular, when the information recording/reproducing apparatus in states 3c and 3d is moved in a direction across trunk 1 or 2, a read waveform as shown in FIG. 2 is obtained.

That is, when the information recording/reproducing device at position 3d is moved toward the arrow A side, the readout signal output level decreases sequentially as shown in FIG. When the signal is moved to the side, the readout signal level first increases sequentially as shown in FIG. 2(B), reaches a peak when on-track, and then decreases sequentially.

Therefore, if the readout signal level changes when the information recording/reproducing device is moved in the direction across the trunk, it can be detected that the information recording/reproducing device is located near the trunk. .

Therefore, in the present invention, this phenomenon is utilized to detect whether or not the information recording/reproducing device is located near the track.

FIG. 3 is a diagram for explaining the off-track detection method in the disk storage device of the present invention.

In the figure, 10 is a peak detection circuit, 20 is a memory circuit,
30 indicates an arithmetic operation and a comparator, and 40 to 90 indicate drivers, respectively.

Although not shown, in addition to the configuration shown in FIG. 3, there is an access mechanism for moving and positioning the information recording/reproducing device to a desired track on the recording medium, a control circuit for controlling the access mechanism, and an information recording/reproducing device. A sending circuit that sends information to be recorded to the device.

An amplifier or the like is provided to amplify the read signal from the information recording/reproducing device at a predetermined amplification factor.

The disk storage device including these devices is connected to an adapter and a control device, and has an interface control section for transmitting and receiving data, instructions, commands, etc. to and from a host device.

These configurations are detailed in ``Computer Systems Viewed from Technical Trends Series Patents'' published by the Japan Institute of Invention and Innovation on April 10, 1981.

First, an access mechanism (not shown) positions the information recording/reproducing device at a desired track on the recording medium, and then information is read from the trunk to confirm that it is positioned at the desired trunk.

At this time, if the information cannot be read, it is detected by the configuration shown in FIG. 2 whether or not the information cannot be read by off-track.

First, a control circuit for operating the access mechanism is programmed to offset the information recording/reproducing device, that is, to move it in a direction across the trunk.

This movement is performed in steps by a predetermined movement length in the directions of arrows A and B shown in FIG.

For example, it is sequentially moved in steps by 0.54 in the direction of the starting arrow A, returned to the original position at the start of offset after advancing n steps, and conversely moved in the direction of arrow B in the same stepwise manner.

These steps are programmed in the control circuit so that they can be moved in a predetermined sequence.

During this offset operation, information is read by the information recording/reproducing device.

From the control circuit, a signal indicating what kind of movement instruction is given to the access mechanism is transmitted to each driver 40 to 90, and the driver is selectively driven at each step position.

On the other hand, a read signal is input from the amplifier to the peak detection circuit 10.

The peak detection circuit 1o outputs the peak of the readout signal input to the peak detection circuit 10, that is, the average value of the time required for the recording medium to go around once, according to signals selectively given from each of the drivers 40 to 9o, and outputs the average value of the time required for the recording medium to go around once. 20, for the address selected by the drivers 40 to 9o,
Record the peak value.

When the off-cent operation is completed and the peak values of each step are input into the memory 2o, the arithmetic circuit and comparator 30 compare the respective peak values, and when the phenomenon explained in FIG. 2 appears, an off track signal is sent out. , and in other cases, a non-off-trasok signal is sent.

Therefore, it is possible to detect whether the reason why the information continuous signal cannot be obtained is due to off-track or something else.

Although this calculation and comparator 30 is configured to detect only whether the vehicle is off-trunk or not, it is also possible to detect the direction of off-track.

<Effects of the Invention> As described above, in the present invention, information can be recorded/reproduced near the track by moving the information recording/reproducing device in the direction across the track and measuring the read signal and output level at that time.
It becomes possible to detect whether or not the playback device is located, making it easy to isolate the problem.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the off-track phenomenon according to the present invention, and FIG. 2 shows a read signal waveform obtained when the information recording/reproducing device is moved in a direction across the trunk.
FIG. 3 shows diagrams for explaining the off-track detection method in the disk storage device of the present invention. Furthermore, in the figure, 1 and 2 are trunks, 3 is an information recording/reproducing device, 10 is a peak detection circuit, 20 is a memory circuit, 3
0 indicates an arithmetic operation and a comparator, and 40 to 90 indicate drivers, respectively.

Claims (1)

[Claims] 1) A disk storage device that records and reproduces information by selectively positioning an information recording/reproducing device with respect to a plurality of recording tracks, in which the information recording/reproducing device is positioned on a trunk to be recorded/reproduced. If the information recording/reproducing device cannot be detected, move the information recording/reproducing device in a direction across the track, and if the readout signal obtained at that time increases or decreases, it is determined that the information recording/reproducing device is located at least near the trunk. A method for detecting off-trunk in a disk storage device, characterized by detecting.