JPH01169772A - Information memory - Google Patents

Abstract

PURPOSE:To prevent the recording information dissipation of a magnetic disk by providing a comparator, comparing a variable gain amplifier position signal and a reference signal and commanding the transferring of an information signal with a generated pulse signal. CONSTITUTION:A gain adjusting signal is outputted from a computer 20, and a variable gain amplifier 32 is adjusted to a regular amplifying gain with D/A converting. Besides, the computer 20 makes a positioning command signal input a corresponding driving current through a servo circuit 21 to the amplifier 32. The driving current amplified by the amplifier 32 detects a position signal with a position sensor 13 with making a magnetic head move in the radius direction of a magnetic disk 3, moreover, detects a speed signal with a speed demodulation circuit 22. The position signal and the speed signal are fed back to the circuit 21. Then, the position signal is detected with the sensor 13, the position signal and the above-mentioned gain signal are compared with a comparator 33 with position controlling, the result is instructed to the computer 20 with an output pulse signal, and an information signal is transferred. Consequently, the head 4 falls on the recording face of the disk 3, and the recording information of the disk 3 is prevented to dissipate.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention records information or reproduces recorded information by means of relative movement between a disk-shaped record carrier and a head held close to its recording surface. The present invention relates to an information storage device capable of storing information.

[Conventional technology]

FIG. 3 is a sectional view including the side surface of a conventional information storage device similar to that shown in, for example, Japanese Patent Application Laid-Open No. 60-101777, and FIG. 4 is a sectional view including the side surface of this information storage device. FIG. 2 is a block diagram showing a positioning control system of the device. In Figure 3, (1) is a support stand, (2) is a spindle motor fixed to this support stand, and (3) is a magnetic disk of a disk-shaped record carrier fixed to the rotating shaft of this spindle motor. A recording medium for recording information is attached to the surface of the recording medium.

(4) is a magnetic head which is held close to the recording surface of the magnetic disk (3) and converts an electrical signal corresponding to information into a change in the magnetic state of the recording surface or vice versa;
(5) is a pressure spring that supports and pressurizes the magnetic head (4); (6) is an arm that fixedly supports this pressure spring;
l is an actuator αυ that linearly moves the magnetic head (4) in the radial direction of the magnetic disk (3) via this arm and a pressure spring (5), and αυ is a carrier 7 to which the arm (6) is fixed. Then, put on a hair ring and move on the support stand (tl). θno is the carriage Oo above
The drive coil mounted on the drive coil, α, is a position sensor, which is composed of an optical scale fixed to the carriage 0υ and a photosensor fixed to the support base 11). 09 is a yoke forming a magnetic path, and Oo is a permanent magnet attached to this yoke.

In FIG. 4, (to) is an electronic computer that performs information processing such as the positioning control n system, and (21) is a servo circuit that receives a positioning command signal from the electronic computer ate and is connected to the position detected by the position sensor Q31. While comparing the signal and the speed signal obtained by differentially shaping the position signal, the drive coil 0 of the actuator G[I is energized to drive the carriage 0υ. (22) is the speed 53 obtained by differentially shaping the position signal detected by the position sensor 03 above.
(23) a read/write circuit which receives the recording/reproduction command No. 13 from the electronic computer 4 and transfers the information to the magnetic disk (3) via the magnetic head (4); recording or reproducing recorded information.

Next, the operation will be explained with reference to FIG. Fifth
The figure is a waveform chart showing the position signal output by the position sensor OJ when the magnetic head 4) is positioned on a predetermined track of the magnetic disk 3 and is in a state of hydrodynamic spacing with the recording surface. First, the spindle motor (2
) is energized and the magnetic disk (3) is rotated at a predetermined number of rotations, the magnetic head (4) held close to the recording surface receives a buoyant force due to the viscous air flow generated on the recording surface, and the pressure is applied. A state of hydrodynamic spacing is established in which a predetermined gap is maintained between the recording surface of the 6n air disk (3) and the recording surface of the 6N air disk (3) in equilibrium with the pressurizing force (5).

In this state, when a positioning command signal is output to the servo circuit (21) in the electronic meter Under the action of the magnetic field of the magnetic path consisting of the permanent magnet Oe and the air gap, the carriage 0υ is driven according to Fleming's left hand rule, and the magnetic head (4) moves in the radial direction of the magnetic disk (3). Along with this movement, the position sensor 0■ detects a position signal, and the speed demodulation circuit (22) differentially shapes this position signal to detect the speed signal, and the servo circuit (21) converts it into an electronic computer (
The magnetic head (4) is positioned on a predetermined track of the magnetic disk (3) while comparing it with the positioning command signal from the magnetic disk (3). Thereafter, the position sensor α1 continues to detect a position signal (see FIG. 5), and based on this position signal, the process moves to position control for causing the magnetic head (4) to follow the predetermined track. and an electronic computer (21I) read/write circuit (23
) to record information on the magnetic disk (3) via the magnetic head (4) or to reproduce the recorded information.

By the way, the servo system consisting of the servo circuit (21), actuator 0 [, position sensor a1, and speed demodulation circuit (22)] is a stable control system that can obtain good response by adjusting the gain of its round transfer function. It has become. The criteria for making this gain adjustment include the phase margin, which indicates the phase angle that can be delayed before the servo system becomes unstable, and the gain margin, which indicates the gain that can be increased. The gain margin is usually adjusted to several 6B (decibels).

[Problems to be Solved by the Invention] In the conventional information storage device as described above, the magnetic head (4) and the magnetic disk (4) are in a state of hydrodynamic spacing.
If contaminants are present in the gap between the magnetic head (4) and the recording surface of the magnetic head (4), or vibrations or shocks are applied to the support (1+), the magnetic head (4)
) comes into contact with the recording surface of the magnetic disk (3), producing a fundus on the recording surface of the magnetic disk (3) and the magnetic head (4), causing a change in the buoyancy of the disk (4) due to the magnetic field. There was a problem in that after a month had passed, the magnetic throat (4) would fall onto the recording surface of the magnetic disk (3) and the recorded information on the magnetic disk (3) would be lost.

This invention was made in order to solve this problem, and the object is to obtain an information storage device that can prevent the magnetic head from falling onto the recording surface of the magnetic disk and causing the information recorded on the magnetic disk to disappear. shall be.

[Means for solving problems]

An information storage device according to the present invention holds a head close to the recording surface of a rotating disk-shaped record carrier, and outputs a drive current from a servo circuit based on a positioning command signal from an electronic computer to drive an actuator equipped with the head. The head is moved in a direction across tracks provided concentrically on the recording surface of the record carrier, and position signals corresponding to the position and speed of the head on the recording surface are detected and used as positioning command signals. In a device that positions the head on a predetermined track on the recording surface while comparing, the amplification gain is adjusted to:A based on the gain adjustment signal from the electronic computer, and the variable gain amplifier amplifies the drive current output from the servo circuit, the position signal and the external The device is equipped with a comparator that compares the position signal with a reference signal and outputs a pulse signal when the position signal exceeds the reference signal.

[Effect]

In this invention, the variable gain amplifier adjusts its amplification gain based on the gain adjustment signal from the electronic computer, and the drive N? output from the servo circuit is adjusted. A is amplified, the actuator is driven with this amplified drive current, a position signal is detected, this position signal is compared with an external reference signal using a comparator, and when the position signal exceeds the reference signal, a pulse signal is generated. The computer is commanded to transfer the information signal outputted and recorded on the record carrier.

[Embodiments of the invention]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG.
The figure shows the reference signal (4) and the position signal (
FIG. 4 is a waveform diagram showing pulse No. 13 (C) output from the comparator. In Figure 1, (2) to (41,0ψ, 0
3. The f2 field ~(23) is exactly the same as the above conventional device. (3I) is a D/A converter that converts a digital quantity into an analog quantity, (32) is a variable gain amplifier that adjusts the amplification gain based on gain adjustment No. 18 from the above-mentioned computer (to), and (33) is the above-mentioned This is a comparator that compares the position signal from the position sensor 0 with a reference signal from the outside and outputs a pulse signal when the position signal exceeds the reference signal.

Next, the operation of the above embodiment will be explained with reference to FIG. First, when the spindle motor (2) is energized and the magnetic disk (3) is rotated at a predetermined number of revolutions, the magnetic head (4) held close to the recording surface receives buoyancy due to the viscous air flow generated on the recording surface. The receiver is in a state of hydrodynamic spacing that maintains a predetermined gap with the recording surface of the magnetic disk (3) in equilibrium with the pressing force of the pressure spring (5). In this state, the electronic computer (to) outputs a gain adjustment signal to the D/A converter (
31) into an analog quantity, and then a variable gain amplifier (3
2) is adjusted to a regular amplification gain, and a positioning command signal is output from the electronic computing engine to the servo circuit (21), and the servo circuit (21) outputs a drive current corresponding to this positioning command signal. This drive current is transferred to a variable gain amplifier (
32) and drives the actuator 0ω equipped with the magnetic head (4) to move the magnetic head (4) onto the magnetic disk (
3) while moving in the radial direction, the position sensor 031 detects position No. 13, and this position signal is sent to the speed demodulation circuit (2).
Step 2) performs differential shaping to detect speed No. 13. The position signal and speed signal are fed to the servo circuit (2I), and the magnetic head (4) is positioned on a predetermined track of the magnetic disk (3) while being compared with the positioning command signal from the electronic computer 01. After that, the position sensor o1 continues to detect a position signal, and the control moves to 11 to make the magnetic head (4) follow the predetermined track based on the l signal, and a comparator compares this position signal with an external reference signal. (33
) to compare. At this time, the variable gain amplifier (32) is adjusted to the normal amplification gain, so the magnetic field (4) may contact or fall onto the recording surface of the magnetic disk (3), causing a transient vibration waveform to be superimposed on the position signal. Even if the reference signal is current, the comparator (33) does not output a pulse signal. Next, for example, once every few months, the electronic computer QI outputs a gain adjustment signal different from the above, converts it into an analog quantity with the D/A converter (31), and then adjusts the amplification gain of the variable gain amplifier (32). Adjust it to make it higher and connect the servo circuit (2
1), variable gain amplifier (32), actuator (II
When the servo system consisting of the position sensor G1 has almost no gain left, the servo system becomes unstable and the position signal starts to oscillate slowly (as shown by the solid line waveform in Figure 2 (B)). ), at this time, if the magnetic head (4) contacts or falls onto the recording surface of the magnetic disk (3) and a transient vibration waveform is superimposed on the position signal (see the broken line waveform in Figure 2 (B)), this A part of the transient vibration waveform is the reference signal (Fig. 2 (A)
)) and the pulse signal (second
(See figure (C)).

The electronic computer (to) outputs a reproduction command signal to the read/write circuit (23) using this pulse signal, and the magnetic head (4)
), the information recorded on the magnetic disk (3) is reproduced and transferred to, for example, the memory of an electronic computer (to) for re-recording.

In the above embodiment, the actuator Ql is driven by the magnetic head (
4) in the radial direction of the magnetic disk (3), the position sensor side detects a position signal, and this position signal is differentially shaped by a speed demodulation circuit (22) to detect a speed signal and compare it with the positioning command signal. However, a reference servo method was adopted in which the magnetic head (4) is positioned on a predetermined track of the magnetic disk (3), but the metal part on one side of the magnetic disk (3) is used as a servo surface, and the servo information recorded on this servo surface is used. Servo surface for positioning the magnetic head (4)
It may also be a data surface servo method in which the magnetic disk (3) is entirely a data surface, servo information is embedded in this data surface, and the magnetic head (4) is positioned based on this servo information. There may be.

〔Effect of the invention〕

As explained above, this invention holds a head close to the recording surface of a rotating disk-shaped record carrier, outputs a drive current from a servo circuit based on a positioning command signal from an electronic computer, drives an actuator equipped with the head, and records data. The head is moved in a direction across tracks provided concentrically on the recording surface of the carrier, and position and speed signals corresponding to the position and speed of the head on the recording surface are detected and compared with the positioning command signal. What is the gain from the electronic computer in positioning the head to a predetermined track on the recording surface? A variable gain amplifier that adjusts the amplification gain based on the J4 adjustment signal and amplifies the drive current output by the servo circuit. Compares the position signal with an external reference signal and outputs a pulse signal when the position signal exceeds the reference signal. This pulse signal instructs the electronic computer to transfer the information signal recorded on the record carrier, thereby preventing the magnetic head from falling onto the recording surface of the magnetic disk and causing the recorded information on the magnetic disk to be lost. There is an effect that can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG.
The figure shows the reference signal (A), position signal (B), and pulse signal (C).
), FIG. 3 is a sectional view including a side view of a conventional information storage device, and FIG. 4 is a waveform diagram showing the information storage device shown in FIG. 3! ! FIG. 5 is a block diagram showing a positioning control system of the apparatus. FIG. 5 is a waveform diagram showing a position signal when a magnetic head is positioned on a predetermined track of a magnetic disk. In the figure, (2) is the spindle motor, (3) is the magnetic disk, (4) is the magnetic head, 001 is the actuator, 01 is the position sensor, Q@ is the electronic computer, (21) is the servo circuit, and (22) is Speed demodulation circuit, (31) is D/
A converter, (32) is a variable gain amplifier, and (33) is a comparator. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Masuo Oiwa Figure 1 Figure 2

Claims (1)

[Claims] A head is held close to the recording surface of a rotating disk-shaped record carrier, and based on a positioning command signal from an electronic computer, a drive current is output from a servo circuit to drive an actuator equipped with the head, which is arranged concentrically on the recording surface. The head is moved in a direction across the recorded tracks, and a position signal and a speed signal corresponding to the position and speed of the head on the recording surface are detected, and the signals are compared with the positioning command signal to determine a predetermined position on the recording surface. In the apparatus for positioning the head on the track, a variable gain amplifier adjusts the amplification gain based on the gain adjustment signal from the computer and amplifies the drive current output from the servo circuit, and a variable gain amplifier that amplifies the drive current output from the servo circuit; and a comparator that outputs a pulse signal when the position signal exceeds the reference signal, and the pulse signal instructs the electronic computer to transfer the information signal recorded on the record carrier. Information recording device.