JPS61141016A - Positioning device for magnetic head - Google Patents

Abstract

PURPOSE:To prevent a high-speed collision between a magnetic head and a stopper by setting the shift speed of the head at a reference speed or a limit speed that has the smaller absolute value even in case the target position of the head is indicated at a place out of an allowed mobile range. CONSTITUTION:A target position signal 12a delivered from an upper controller 12 is supplied to the 1st counter means 17 of the 1st setting means 19. At the same time, the 1st signal 14a given via a signal converting means 16 is also supplied to the means 17 from a drive mechanism 9 for a magnetic head 2. A position deviation signal 17a is delivered from the means 17, and a motor 4 of the mechanism 9 is controlled via the 1st control means 23, etc. Here the 2nd counter means 25 is added together with the 2nd setting means 28 consisting of the 2nd limit speed producing means 26 and 27 and the 2nd control means 31 consisting of a discriminating means 29 and an open/close means 30. Thus the shift sped of the head 2 is set at a reference speed 18a, the limit speed 26a or 27a that has the smallest absolute speed even in case the target position of the head 2 is commanded at a place out of an allowed mobile range by the device 12, etc., and outputted.

Description

[Detailed Description of the Invention] [Technical Field to which the Invention Pertains] The present invention relates to a magnetic head positioning device in a magnetic disk device used in a combination data storage device, etc. The present invention relates to a positioning device.

[Prior art and its problems]

In the above-mentioned magnetic disk devices, etc., it is required to position the magnetic head at high speed, and the magnetic head is therefore driven by a voice coil motor, such as a pulse motor, which does not have a self-locking mechanism. A voice coil motor has a moving coil wound around a magnetic path of a permanent magnet, and uses the force generated in the coil when the moving coil is energized to drive a magnetic head. FIG. 6 is a schematic configuration diagram of a conventional magnetic head positioning device in a magnetic disk device using such a voice coil motor, where 1 is a magnetic disk and 2 is a magnetic head. The magnetic head 2 is hinged to one end of a lever 3, and a motor 4 is connected to the other end of the lever 3.
The lever 3 is configured to be driven in the axial direction of the lever 3 by a motor 4 while being supported by a bearing 5. In this case, the magnetic head 2 is moved over the magnetic disk 1 through a narrow gap by the axial movement of the lever 3. 6 is a retaining member fixed to the lever 3, 7 is a first stopper, 8 is a second stopper, and both stoppers 7.8 are such that when the lever 3 moves, the retaining member 6 comes into contact with either stopper and the lever is closed. 3 is arranged so that the movement range of the robot 3 is limited. This arrangement of the stopper 7.8 is provided to prevent mechanical and electrical problems caused by the magnetic head 2 moving beyond the permissible movement limit on the surface of the magnetic disk 1. There is. Reference numeral 9 denotes a magnetic head drive mechanism comprising the lever 3, motor 4, bearing 5, engaging member 6, and stoppers 7 and 8 described above. A detection sensor 10 detects the moving state of the magnetic head 2 driven by the magnetic head drive mechanism 9. In this case, the detection sensor 10 will be described later.

The motor 4 is configured with an encoder attached to the motor 4, which outputs a signal like this. Reference numeral 11 receives the output signal 10a of the detection sensor 10 and the target position signal 12a output from the host controller 12 such as a combiator, and generates a drive signal 11a.
The magnetic head drive mechanism 9 is a control device that outputs a target position signal 12 in which the magnetic head 2 is controlled by a drive signal 11a.
It is controlled to be positioned at a position corresponding to a. 1
3 is a magnetic head positioning device consisting of a detection sensor 10 and a control device 11.

FIG. 7 is a block diagram of the positioning device 13 of FIG. 6, and the operation of the positioning device 13 of FIG. 6 will be explained below using FIG. 7 as well. 6 and 7, 101
is a movement direction signal as a binary electric signal outputted from the detection sensor 10 in accordance with the movement direction of the magnetic head 2 accompanying the movement of the lever 3, and thus in accordance with the rotation direction of the motor 4; As a position change signal of the magnetic helad 2 output from the detection sensor 10 in accordance with the position change of the magnetic head 2 as the magnetic head 2 moves, and therefore in accordance with the rotation of the motor 4 at every predetermined angle. The output signal 10a of the detection sensor 10 is composed of the above-mentioned moving direction signal 101 and position signal 102. 14 receives the signals 101 and 102, and increases the electric pulse signal from the first terminal 14b according to the temporal change of the current position Xf of the magnetic head 2 when the moving direction signal 101 is a positive direction signal. When the moving direction signal 101 is a reverse direction signal, the second terminal 1 is outputted as a signal 141.
gate means for outputting as a reduced signal 142 from 4c, 14;
a is a g1 signal consisting of an increase signal 141 and a decrease signal 142. 15 is a moving direction signal 101 and a position change signal 102
is input, the number of electric pulses included in the signal 102 within a unit time is counted, and a second signal 15a corresponding to the rotational speed of the motor 4, and thus the moving speed of the magnetic head 2, is generated.
A speed detection means that outputs as a positive sign analog signal when the signal 101 is a positive direction signal and as a negative sign analog signal when the signal 101 is a reverse direction signal,
Reference numeral 16 denotes a signal conversion means which includes the gate means 14 and the speed detection means 15 and outputs the first signal 14a and the second signal 15a as described above.

The target position signal 12a outputted from the host controller 12 has a resistance and a number according to the difference between the target position Xt of the magnetic head 2 and the position of the magnetic head immediately before the target position signal is output (immediate position). an electric pulse signal having 1
Reference numeral 7 denotes an M1 counting stage in which the target position signal 12a is first input and the polarity and number of electric pulses in the signal are stored.

When the first signal 14a is input after the target position signal 12a is input, the first counting means 17 calculates that if the signal 14a is an increased signal 141, the electric pulse constituting the signal 141 is input. 141, and outputs a signal corresponding to the result of the subtraction as a position error signal 17a, which changes over time as the signal 141 is input. Signal 14a is reduced signal 1
42, each time an electric pulse constituting the signal 142 is input, addition is performed to the stored value of the counting means 17, and a signal corresponding to the addition result and corresponding to the input of the signal 142 is added. It is configured to output a signal that changes over time as a positional deviation signal 17a having a different sign from the positional deviation signal. Since the counting means 17 is configured as described above, the position deviation signal 17a is a signal corresponding to the deviation ΔX of the current position ftXt of the electric head 2 from the eye tilt position Xt commanded by the host controller [12]. It is. Reference numeral 18 denotes a reference speed generating means which receives the position deviation signal 17a and outputs a reference speed signal 18a8 as a digital signal according to this input signal according to the reference speed characteristic diagram shown in FIG. This is a first setting means consisting of a generating means 18. @ In Figure 8, the horizontal axis represents the positional deviation ΔX, and the vertical axis represents the reference speed vr.
In the diagram of FIG. 8, the speed vr takes negative and positive values depending on the positive value of the deviation ΔX, and when the absolute value of the deviation ΔX is ΔX3 or more, the absolute value of the speed vLar becomes Vrl, If the absolute value of the deviation ΔX is smaller than ΔX, the absolute value of the speed vr is proportional to the square root of the absolute value of the deviation ΔX. The reference speed signal 18a is a signal that commands the moving speed of the magnetic head 2, and as is clear from the fi8 diagram, the reference speed vr becomes zero when the deviation ΔX becomes zero.

In FIG. 7, 20 is a D/A conversion circuit that receives the reference speed signal 18a and outputs an analog signal 20a according to the signal, and 21 receives the signal 20a and the second signal 15g and converts it according to the difference between the two signals. The deviation generation circuit outputs the signal 21a, and since the signal 21a is a signal formed as described above, it is the reference speed DtVr of the current moving speed of the magnetic head 2.
This signal corresponds to the deviation from 22 is a drive circuit that amplifies the speed deviation signal 21a and outputs a drive signal 11a for driving the magnetic head drive mechanism 9; 23 is a first drive circuit that includes a D/A conversion circuit 20, a deviation generation circuit 21, and a drive circuit 22;
The first control means 23 controls the magnetic head drive mechanism 9 using the drive signal 11a and converts the signal 15a into a signal 20.
It operates to match a. The control device tll is composed of a single signal conversion means 1G, a first setting means 19, and a first control means 23.

Since the magnetic head positioning device 13 is configured as described above, when the positional deviation ΔX becomes zero, the reference speed vr becomes zero, and as a result, the magnetic head 2 is positioned at the position Xt according to the target signal 12a. When the host control unit ft12 malfunctions and commands the target position of the magnetic head 2 to be at a position where the engaging member 6 of the lever 3 exceeds the movement range defined by the stopper 7.8, the lever 3 moves to the stopper 7.8. It stops after colliding with 7 or 8. For example, as shown in the wce diagram, when the current position +ytXr of the magnetic head 2 is at the reference position corresponding to the innermost track of the magnetic disk 1, the target signal 12a is determined by the stopper 7 or 8. When a position Xtt beyond one end point Xl of the movement range of the magnetic head 2 is commanded, in this case, since the control device 11 and the magnetic head drive device 9 are configured as described above, the magnetic head 2 moves as shown in FIG. The magnetic head 2 moves according to the speed pattern shown in FIG. 2, and stops with a very large negative acceleration after colliding with the stopper 7 or 8:# engaging member 6. Therefore, at this time, an excessive impact force is generated on the magnetic head 2 and the drive mechanism 9iζ, and as a result, the nuclear magnetic head and the recording surface of the magnetic disk l may be damaged. For this reason, one possible method would be to detect the end of the allowable movable range of the magnetic head 2 without providing the stopper 7.8, and apply a brake appropriately outside this movable range to stop the magnetic head. If this method is adopted, there is a problem that the movable range of the magnetic head becomes wide as a result, and the positioning device for the head becomes large. Even if an attempt is made to apply the brake to the magnetic head from a position that is inside the movable range by a corresponding distance, the braking distance will depend on the speed of the magnetic head at the time the brake is started and the degree of braking. As a result, this magnetic head stopping method has a problem in that the braking start position cannot be determined.

[Purpose of the invention]

The present invention solves the problems in the conventional magnetic head positioning device as described above, and even if the target position of the magnetic head is commanded to a position beyond the permissible movable range of the magnetic head, the magnetic head drive mechanism It is therefore an object of the present invention to provide a magnetic head positioning device that does not damage, for example, a magnetic disk and therefore does not require expanding the movable range of the magnetic head.

[Key points of the invention]

In order to achieve the above-mentioned object, the present invention includes a detection sensor that outputs a movement direction signal corresponding to the movement direction of a magnetic head and a position change signal corresponding to a position change accompanying the movement of the magnetic head; A moving direction signal and a position change signal are input,
signal converting means for outputting a first signal according to the current position of the magnetic head and a moving direction signal; and outputting a second signal according to the moving speed of the magnetic head; a first setting means that receives a corresponding target signal and outputs a reference speed signal corresponding to the deviation of the current position of the magnetic head from the target position; output to the head drive mechanism and
a first control means for controlling the magnetic head drive mechanism so that the signal is equal to the reference speed signal; and a magnetic head positioning device that receives the tJc1 signal and outputs a speed limit signal according to the current position of the magnetic head. a second setting means; and a second control means which receives a reference speed signal and a speed limit signal and outputs a signal with a smaller absolute value of both signals as a speed command signal, and the speed command signal is used as a reference. The device is configured to input the speed signal to the first control means, and by configuring it in this way, the target position of the magnetic head can be controlled by the host control device etc. to exceed the allowable range of movement of the magnetic head. Even if the magnetic head is commanded to a specified position, the moving speed of the magnetic head is limited to the smaller absolute value of both the reference speed and the limit speed, and as a result, the magnetic head drive mechanism collides with the stopper at high speed. Therefore, it is possible to obtain a magnetic head positioning device in which the magnetic disk is not damaged by the movement of the magnetic head, and there is no need to expand the movable range of the magnetic head.

[Embodiments of the invention]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. The difference between FIG. 1 and FIG. 7 is that the second setting means 28 includes a second counting means 25, first and second speed limit generating means 26, 27, a determining means 29, and an opening/closing means 30. A second control means 31 is provided. In FIG. 1, 32 is a reference signal composed of a number of electric pulses corresponding to the reference position of the magnetic head 2;
Reference numeral 5 denotes a second counting means to which the reference signal 32 is input in advance and the number of electric pulses is stored. Second counting means 2
In addition to the reference signal 32, the first signal 1411 is also input to the counter 5, and in the counting means 25, the signal 14a is converted into the increased signal 14.
1, the value stored in the counting means 25 is successively added to the value stored in the counting means 25 each time an electric pulse constituting the signal 141 is input, and when the signal 14a is a reduced signal 142, the signal 142 is The counting means 25 is configured so that each time the constituent electric pulses are input, subtraction is performed successively from the stored value of the counting means 25, and a signal corresponding to the result of the addition/subtraction is outputted as 25a.

Since the output signal 25a is a signal output as described above, it is a signal that changes over time as the first signal 14a is input to the second counting means 25, and also changes over time as the first signal 14a is input to the second counting means 25. This is a position signal corresponding to the position Xf. 26.2
7 receives a position signal 25 and a moving direction signal 101, respectively, and outputs first and second speed limit signals 26a and 27a as digital signals corresponding to these input signals.
In FIG. 2, the horizontal axis represents the position X of the magnetic head, and the vertical axis represents the position X. When the first speed limit generating means 26 receives the signal 25a, it outputs the signal 26a according to the characteristics shown by the solid line in FIG. The speed generating means 27 has a characteristic of outputting a signal 27a according to the characteristic indicated by the dotted line in Fig. 2 when the signal 25a is input.In Fig. 1, when the moving direction signal 101 is a forward direction signal, When the first speed limit generation means 26 operates and the signal 26a is output, and when the moving direction signal 101 is a negative direction signal, the second speed limit generation means 2 and 7 operate and the signal 27a is output. .In Figure 2, Xu.

Xd are the positive direction end and the negative direction end of the movable range of the magnetic head, respectively. In this case, the reference position is set to coincide with the position Xd, and the characteristics of the solid line are the positions Xd and
The speed limit becomes a constant value of +V1+ between u, and the speed limit becomes zero at position Xu, and the characteristic of the dotted line is at position Xu.
The speed limit is set to a constant value of -V/l between and the position Xds, and the speed limit becomes zero at the position Xd.

In FIG. 1, the second counting means 25 and the first and second speed limit generating means 26, 27 are constructed as described above, so the second setting means 28 consisting of these means 32 and the first signal 14a are input thereto, and has a function of outputting a speed limit signal V corresponding to the current position #Xf of the magnetic head 2. 29 are reference speed signals 18a and 8g1 and second speed limit signals 26a, 27
a and the moving direction signal 101 are input, and if the signal 101 is a positive direction signal, the first speed limit signal 26a and the reference speed signal 18a are compared and the one with the smaller absolute value of both signals is selected. The first discrimination signal 29a is outputted to select the signal, and when the signal 101 is a negative direction signal, the second discrimination signal 29a is outputted to select the signal.
It is a determining means that outputs a second determining signal 29b so as to compare the speed limit signal 27a and the reference speed signal 18a and select the signal with the smaller absolute value of both signals. 30
are the reference speed signal 18a, the first and second III limited speed change speed signals 26a7a and gl, and the second discrimination signal 29a,
29b is input, and the reference speed signal 18a selected by the discrimination signals 29a and 29b or the limit speed signal 26a
, 27a as the speed command signal 30a.
This is a signal opening/closing means for outputting to the A conversion circuit 20. Reference numeral 31 denotes a second unit consisting of the above-mentioned discriminating means 29 and signal opening/closing means 30.
Control means 33 is signal conversion means 16 and first setting means 19
34 is a magnetic head positioning device consisting of the control device 33 and the detection sensor 1o.

The positioning device 34 in FIG. 1 is constructed as described above, but in this case, the shape of the limit speed characteristic line shown in FIG. 2 and the reference speed characteristic line shown in FIG.
Both characteristic lines are shown in comparison in FIG. 4 and FIG. In other words, Fig. 3 shows the position Xu in Fig. 2 and the
ΔX= in the figure.

The solid characteristic line in Figure 2 and the characteristic line at ΔX40 in Figure 8 are superimposed so that the origin of Δ in the figure
The dotted characteristic line in Figure 2 and the characteristic line in the part of ΔX≧0 in Figure 8 are superimposed so that the origin of X = 0 coincides with the origin, and it is In this case, the absolute value of the reference speed vr is always smaller than the absolute value of the limit speed V/, regardless of the position RXf. A line is formed. Therefore, in the positioning device [34 of FIG. When a command is given to move Xu, in this case, the first setting means 19 outputs a signal according to the reference speed characteristic line shown in FIG. 3, and the second setting means 28 outputs a signal according to the reference speed characteristic line shown in FIG. As a result, the second control means 31 outputs a signal corresponding to the reference speed characteristic line shown in FIG. 3 as the speed command signal 30a, and this signal indicates that the magnetic head position fi Since it becomes zero when it matches XU, the magnetic head 2 is stopped quietly. When the magnetic head 2 is in a position near the end Xd, an abnormal target signal 12a due to a failure of the host controller 12, etc.
When the magnetic head is instructed to move beyond the end Xu to a position Xu outside the movable range, in this case, the positional relationship between the characteristic line in FIG. 2 and the characteristic line in FIG. 8 is as follows. As shown in FIG. 5, in this case, the second control means 31
Since the signal output from is a signal corresponding to the smaller of the reference speed vr and the limit speed vl, the magnetic head 2 has the speed characteristic shown by the thick line in FIG. 5 as it approaches the end Xu. moves, and this velocity becomes zero at position tl X u. Therefore, in the positioning device t34, even if the target position of the magnetic head is commanded to a positive position exceeding the position Xu, the magnetic head will stop quietly at the position Xu, so the magnetic head drive mechanism will collide with a stopper etc. It does not cause any damage to discs etc.

The above explanation is for the case where the target position of the magnetic head is commanded to a position in the positive direction exceeding the position Xu, but in the present invention, the reference speed characteristic line and the limit speed characteristic line are as explained in FIG. is also formed, so it is clear that if the target position of the magnetic head is commanded to a position in the negative direction exceeding position tXa, the magnetic head will stop quietly at position QjLXd.

〔Effect of the invention〕

As described above, in the present invention, an ejection sensor outputs a moving direction signal corresponding to the moving direction of the magnetic head and a position change signal corresponding to the position change accompanying the movement of the magnetic head; and a position change signal, and outputs a first signal according to the current position and moving direction signal of the magnetic head, and outputs a second signal according to the moving speed of the magnetic head; 1 signal and a target position signal corresponding to the target position of the magnetic head, the first setting means outputs a reference speed signal corresponding to the deviation of the current position of the magnetic head from the target position; The second signal is input and a drive signal is output to the magnetic head drive mechanism.
In a magnetic head positioning mechanism, the first control means controls the magnetic head drive mechanism so that the 22nd signal is equal to the reference speed signal; A second setting means for outputting a speed command signal; and a second control means for receiving a reference speed signal and a speed limit signal and outputting a signal having a smaller absolute value of both signals as a speed command signal. is input to the first control means instead of a reference speed signal, so by configuring it in this way, it is possible to prevent the target position of the magnetic head from exceeding the permissible movement range of the magnetic head by a host controller, etc. Even if the position is commanded, the moving speed of the magnetic head is limited to the smaller absolute value of both the reference speed and the limit speed, and as a result, the magnetic head drive mechanism collides with the stopper at high speed. The magnetic disk is not damaged, and therefore a magnetic head positioning device that does not require expanding the movable range of the magnetic head can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a limit speed characteristic line, and Figs. 3, 4, and 5 are different comparisons between the limit speed characteristic line and the reference speed characteristic line. Explanatory drawings, Figures 6 and 7 are a configuration diagram and block diagram of a conventional magnetic head positioning device, respectively, Figure 8 is a reference speed characteristic diagram, and Figure 9 is a diagram of the speed pattern of the magnetic head in Figure 6. be. 2...Magnetic head, 9...Magnetic head drive mechanism, 10
...Detection sensor, 11a... Drive signal, 12a...
Target signal, 13.34...Magnetic head positioning device,
14a...first signal, 15a...second signal, 16...
- Signal conversion means, 18a... Reference speed signal, 19...
・First setting means, 23...First control means, 26a...
・First speed limit signal, 27a・, Second speed limit signal, 2
8... Second setting means, 30a... Speed command signal, 3
1..., second control means, 32... reference signal, 101...
・・Movement direction signal, 102.1 position change signal, so...
Reference position, Xf...Current position, Xt...Target position. f21! l '2"3 b 4th
■ f5 figure gait 9 years old

Claims (1)

[Claims] a detection sensor that detects a moving state of a magnetic head driven by a magnetic head drive mechanism and outputs a moving direction signal corresponding to a moving direction of the magnetic head and a position change signal corresponding to a position change of the magnetic head; the moving direction signal and the position change signal are input, and outputting a first signal according to the current position of the magnetic head and the moving direction signal;
and a signal conversion means for outputting a second signal according to the moving speed of the magnetic head; the first signal and a target position signal corresponding to the target position of the magnetic head are input, and the current position of the magnetic head is inputted. a first setting means for outputting a reference speed signal corresponding to a deviation from the target position; a first setting means for outputting a drive signal to the magnetic head drive mechanism to which the second signal and the reference speed signal are input; a first control means for controlling the magnetic head drive mechanism so that the signal becomes equal to the reference speed signal; and a magnetic head positioning device for positioning the magnetic head by the magnetic head drive mechanism, a second setting means receiving the first signal and outputting a speed limit signal corresponding to the current position of the magnetic head; receiving the reference speed signal and the speed limit signal and determining the absolute value of both signals; a second control means for outputting a smaller signal as a speed command signal; and the speed command signal is input to the first control means in place of the reference speed signal. Positioning device.