JPS62154385A - Storage device - Google Patents

Abstract

PURPOSE:To detect previously the possibility of an erasure accident of stored information being slightly high by providing a detecting circuit which detects a drop in the voltage of the playback signal which is read out of a disk by a head. CONSTITUTION:When a head 6 floats normally, the voltage of the playback signal of the head 6 from the disk 3 has a normal value, so the output voltage (a) of an amplifier 21 becomes a signal having a waveform with a relatively high crest value. It becomes higher than the output voltage (b) of a reference voltage generating circuit 22 cyclically, the output (c) of a comparator 23 varies periodically, the output (d) of a retrigger one-shot multivibrator 24 becomes a signal with logic 0 at the time of positive logic, so that no detection signal with logic 1 is outputted. When the head 6 and disk 3 begin to damage, the output voltage (a) of an amplifier 21 becomes invariably lower than the output voltage (d) of the reference voltage generating circuit 22. Then, the output (c) does not vary any more and the output (d) is outputted as a detection signal with logic 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a storage device used in electronic computers, computer peripheral terminals, and the like.

[Conventional technology]

FIG. 6 shows, for example, Japanese Patent Application Laid-Open No. FM360-101777,
A conventional storage device used as an example of a storage device as shown in Electronics (April 1985 issue, hard disk, p59-p65, Ohmsha) and Software Knowledge (written by Mitsuharu Yada, 1982, p75-p83, Ohmsha). 1 is a configuration diagram showing a magnetic disk device of FIG. In the same figure,
1 is a support base, 2 is a rotating device such as a spindle motor attached to the support base 1, 3 is a disk such as a magnetic disk as a recording medium attached to the rotating shaft of the rotating device 20, and 4 is an arm whose one end is an arm. A pressure spring 5 is fixed to the head 5, and a head 6, such as a magnetic head, for recording and reproducing is mounted upward at the other end. 7 is a support mechanism that supports the arm 5; 9 is a head moving mechanism that incorporates the support 1 mechanism 7 and moves the head 6 in the radial direction of the disk 30; 10 is a head drive that drives the head moving mechanism 9. It is a circuit. 11 is a recording/reproducing circuit which outputs a recording signal to the head 6 in order to write information on the disk 3, and which uses a signal read from the disk 3 via the head 6 as a reproduction signal; 12 is a disk drive circuit; , the rotation device 2 is driven to rotate. Reference numeral 13 denotes a control device which includes, for example, a central processing unit, etc., and includes a head drive circuit 10. Recording/reproducing circuit 11
and the disk drive circuit 12, and an electronic computer (
(not shown), and inputs information to be recorded on the disc 3 and outputs information reproduced from the disc 3.

Next, the operation will be explained. When information is being recorded or reproduced, the disk drive circuit 12 receives a start command from the control device 13 and drives the rotation device 2 to rotate. When this rotating device 2 is rotationally driven and the disk 3 rotates, a viscous air flow generated on the surface of the disk 30 causes a head 6
A downward buoyant force is generated.

This buoyancy balances the pressure force of the pressure spring 4 that presses the head 6 upward, and the disk 3 is rotated while maintaining a small gap between the disk 3 and the head 6. This results in
The head 6 is arranged facing the disk 3. In this state, when a recording or reproducing command is sent from an electronic computer (not shown) to the recording/reproducing circuit 11 via the control device 13, the recording/reproducing circuit 11 controls the recording/reproducing circuit 11 to write a command to the disk 3 via the head 6. Information is recorded or reproduced from the disc 3. Of course, at this time, the head 6 is connected to the disk 3.
The head moving mechanism 9 receives a drive command from the busy control device 13 via the head drive circuit 10 so as to position the support mechanism 7 on a predetermined track of the disk 3, and drives the support mechanism 7 in the radial direction of the disk 3.

In the conventional example above, one disk is representatively shown, but when a large number of disks are rotated by one rotating device, the busyness is
A head is arranged for each disk. There is also a conventional example in which the control device 13 of the magnetic disk device is incorporated into the control device of the above-mentioned computer. Furthermore, there is also a conventional example in which the support mechanism is supported and fixed to a fixed mechanism, and in this case, the head moving mechanism 9 and head drive circuit 10 shown in FIG. 6 are not required.

[Problem that the invention seeks to solve]

Conventional storage devices have a busy structure as described above, so if dust generated from inside the storage device enters and exits the tiny gap between the head and disk, or if the storage device is exposed to strong photography or impact from outside, the head The head or disk may be damaged due to intermittent or temporary pressure contact with the disk.
After a long period of time, the head will no longer be able to lift off the disk.
There were problems such as the loss of information stored on the disk.

This invention was made in order to solve the above-mentioned problems, and in order to prevent the accident of loss of stored information on a disk, a storage device that can detect in advance that there is a slightly high possibility of the loss of information stored on a disk is provided. The purpose is to obtain.

[Means for solving problems]

The storage device according to the present invention is configured to detect a drop in the voltage of a reproduction signal of a head using a detection circuit.

[For production]

In the storage device in this review, when the head or disk starts to get scratched, the voltage of the reproduction signal of the head decreases.
The detection circuit detects this decreased voltage and outputs a detection signal, thereby making it possible to prevent accidents in which stored information is lost.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, and in the same figure, the constituent elements indicated by reference numerals 1 to 7 are the same as those of the conventional one. Reference numeral 20 denotes a detection circuit, which is comprised of the components described below, and detects a drop in the voltage of the reproduced signal from the head 6. Reference numeral 21 denotes an amplifier that amplifies the reproduced signal from the head 6. 22 is a reference voltage generation circuit that generates a predetermined reference voltage set in advance. 23 is a comparator,
The reference voltage generation circuit 220 inputs the reference voltage to the non-inverting input terminal, and the output signal of the amplifier 21 to the inverting input terminal to compare the input signals. 24 is a retrigger one-shot multivibrator which uses the output signal of the comparator 23 as an input signal and outputs (or does not output) when there is no change (or exists) in the input signal.

Note that symbols a to d are output signal waveforms corresponding to the components indicated by symbols 21 to 24. Note that the other configurations are the same as those described in the conventional example, so they are omitted.

In FIG. 2, the symbol a = d is the same as in FIG. 1 and indicates the signal waveform of each output, and the solid line (or dotted line) indicates the state where there is (or is not) a drop in the voltage of the reproduction signal of the head 6. show.

Next, the operation of this embodiment will be explained. In such a storage device, when the disk 3 is rotating and the head 6 is flying normally, the voltage of the reproduced signal from the disk 3 of the head 6 becomes a normal value, so the output voltage of the amplifier 21 is a becomes a waveform signal with a relatively high peak value as shown by the dotted line, and the output voltage 1 of the amplifier 21 is cyclically higher than the output voltage of the reference voltage generation circuit 22.
The output C of the comparator 23 changes periodically as shown by the dotted line, and the output d of the retrigger one-shot multivibrator 24 is a positive logic signal of logic @0", and the detection signal of logic ""12 is not output. When the head 6 and/or the disk 3 begin to be damaged, the voltage of the reproduced signal from the head 6 decreases depending on the degree of damage, and the output voltage a of the amplifier 21 becomes lower than the peak value shown by the solid line. The waveform becomes very low, and the output voltage a of the amplifier 21 is always lower than the output voltage d of the reference voltage generation circuit 22. As shown by the solid line, the output C of the comparator 23 does not change, and the retrigger one-shot multivibrator 24 The output d is output as a detection signal of logic @l''. This detection signal outputted from the detection circuit 20 is given to an external device of the magnetic disk device, such as an electronic computer, via or without the control device described in the conventional example.

FIG. 3 shows another embodiment, in which most of the parts having the same configuration as the conventional example are omitted from the illustration, and the angle is 3,6°22.23. b
, d are the same as in FIG.

25 is an automatic gain control amplifier which inputs the reproduced signal e from the head 6 and outputs a control voltage f to the inverting input terminal of the comparator 23, so that when the control voltage f becomes high (or low), the gain becomes low (or high). and the control voltage f
becomes higher (or lower) as the output g of the automatic gain control amplifier 25 becomes larger (or smaller). Therefore, as shown in FIG. 4, the automatic gain control amplifier 25
The output g of is always a constant value, but the control voltage f and the output d of the comparator 23 become like the solid line (or dotted line) when there is (or is not) a drop in the voltage of the reproduction signal e of the head 6. , an operation similar to that shown in FIG. 1 is expected. That is,
When the reproduction signal e of the head 6 decreases, the gain of the automatic gain control amplifier 25 increases, and its control voltage f decreases.
The voltage is always lower than the reference voltage of the reference voltage generation circuit 22. Therefore, since the input voltage on the non-inverting input terminal side of the °C comparator 23 is always higher than the input voltage on the inverting input terminal side, the comparator 23 outputs a detection signal of logic 11'' with positive logic.During normal operation, this operation is performed. is the opposite, and comparator 2
3 outputs a logic @0# signal.

FIG. 5 shows an example of application of the present invention, in which 30° and 32 are the first and second magnetic disk drives shown in FIG. It is. The detection signal of the detection circuit 20 of the first magnetic disk device 30 is transmitted from the first magnetic disk device 30 to the electronic computer 3.
1, the computer 31 immediately issues a command to the first magnetic disk device 30 to reproduce information from the disk 3 before the head 6 of the first magnetic disk device 30 becomes unable to fly above the disk 3. However, by storing this reproduced information in the second magnetic disk device 32, it is possible to prevent an accident of loss of stored information.

In each of the above embodiments, the head 6 is used for recording and reproducing, but it does not need to be used for recording and reproducing, and may be used only for reproducing. In this case, a reproducing circuit is used in place of the recording/reproducing circuit described in the conventional example.

Furthermore, although the above embodiments have been described with respect to magnetic disk devices, recording devices and storage devices that utilize optical systems, magneto-optical systems, laser systems, electric field systems, electric charge systems, and other systems may also be used. In many cases, the same effects as in the above embodiment can be achieved.

〔Effect of the invention〕

As described above, the present invention is configured to detect a drop in the voltage of the reproduced signal of the head, thereby preventing an accident in which information stored on the disk is lost due to an accident in which the head becomes unable to float above the disk. This has the effect of being able to detect a button in advance that there is a slightly high possibility of it happening, and making it possible to prevent the accident of its disappearance.

[Brief explanation of drawings]

FIG. 1 is a block configuration diagram of a storage device according to an embodiment of the present invention, FIG. 2 is a waveform diagram of each part of FIG. 1, FIG. 3 is a block configuration diagram showing another embodiment of the invention, and FIG. The figure is the third
FIG. 5 is a block diagram showing an application example of the present invention, and FIG. 6 is a front view showing a conventional storage device. In the figure, 3 is a disk, 6 is a head, 2° is a detection circuit, 22 is a reference voltage generation circuit, and 23 is . 24 is a retrigger one-shot multivibrator, and 25 is an automatic gain control amplifier. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (3)

[Claims] (1) Rotating a disk as a recording medium with a rotating device,
In a storage device in which a head used for at least reproducing information on the disk is arranged opposite to a recording surface of the disk, a detection for detecting a drop in voltage of a reproduction signal of the head obtained by reading from the disk. A storage device characterized by being provided with a circuit. (2) The detection circuit includes a reference voltage generation circuit that generates a reference voltage, a comparator that compares the voltage of the playback signal of the head with the reference voltage, and a retrigger one-shot multivibrator that receives the output of this comparator as input. A storage device according to claim 1, characterized in that the storage device comprises: (3) The detection circuit includes an automatic gain control amplifier that inputs the reproduction signal of the head, a reference voltage generation circuit that generates a reference voltage, and a comparator that compares the control voltage of the automatic gain control amplifier and the reference voltage. A storage device according to claim 1, characterized in that the storage device comprises: