JPS60101774A - Positioning mechanism - Google Patents

Abstract

PURPOSE:To facilitate head positioning adjustment by detecting the output of a reference position detector only when a body to be driven approaches in a reference position direction, and preventing an error in detection of a reference position detection signal to be generated when the driven body leaves the reference position. CONSTITUTION:When a magnetic head 5 approaches in the reference position direction, the FF output signal 12 of a D type FF circuit 11 is at a level H, so a head detection signal 7 is set above a head detection lower-limit level 6a so that the signal turns on before a reference phase signal 8 is generated at time t2 in consideration of the delay of a movement track 5a. When the magnetic head 5 leaves the reference position, on the other hand, the FF output signal 12 falls to a level L. Therefore, the reference phase signal 8 is inhibited by a 3-input AND gate 13 at time t3 to prevent the erroneous detection of the reference position signal, but a detection upper-limit level 6c is set for the prevention against the erroneous detection at time t1 corresponding to the last reference position. Therefore, the set margin of the reference position detector is wide and the adjustment is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a head positioning mechanism for a magnetic disk device, and particularly to positioning a head to a reference position.

[Background of the invention]

FIG. 1 shows a configuration diagram of a positioning mechanism in a conventional magnetic disk drive.

The step motor control circuit 3 provides movement target signals 3a, 3b to the step motor 4 using a movement pulse signal 1 and a movement direction signal 2, and also generates a reference phase signal 8. This reference phase signal 8 is a signal generated for each phase of the step motor 4.

The step motor 4 and the magnetic head 5 are mechanically connected, and the step motor 4 moves the magnetic head 5 in response to movement target signals 3a and 3b.

The M m position detector 6 generates a head detection signal 7 by detecting that the magnetic head 5 approaches a home position (hereinafter referred to as a reference position). The head detection signal 7 and the reference phase signal 8 are ANDed by an AND gate 9 to generate a reference position detection signal 10.

FIG. 2 shows a time chart of the positioning mechanism.

Note that the single time chart is an example when the step motor 4 has four phases. Furthermore, the numbers To-T7 written in the movement pulse signal 1 and the magnetic head position indicate the corresponding track numbers, respectively.

The magnetic head 5 approaches the reference position when the moving direction signal 2 is at the ``H'' level, and moves away from the reference position when the moving direction signal 2 is at the rr L11 level. ) is usually set to the outermost track of +h. When the moving direction signal 2 is at the "I (" level) and a pulse is applied to the moving pulse signal 1, the step motor control circuit 3 controls the As a command, a magnetic spatula (-5
A step motor 4 receives a movement command such as a movement target signal 3a.
(A, B, shown in the moving target signals 3a, 3b,
C and D correspond to each phase of the step motor 4). However, due to the load applied to the step motor 4, the actual movement of the magnetic head 5 lags behind the movement L11 signal 3a and moves along a movement trajectory 5a as shown in the figure. In particular, the faster the movement command becomes, the more noticeable the delay in the movement trajectory 5a becomes.

On the other hand, the movement pulse signal l is, after outputting the movement pulse,
By checking the reference position signal 10, it is detected whether or not the reference position has been positioned. If the reference position signal lO is not detected, the next movement pulse is generated. Therefore, in anticipation of the delay in the movement trajectory 5a, the head detection signal 7 is outputted before the reference phase signal 8 at time t2 is generated.
The head detection lower limit level must be set to 68 or higher so that the head detection level is N.

Next, when a pulse is applied to the movement pulse signal 1 when the movement direction signal 2 is at the "L" level, the movement target signal 3b that controls the step motor 4 so that the magnetic head 5 moves away from the reference position is transmitted to the step motor control circuit. 3, but the actual moving trajectory 5b is delayed with respect to this moving target signal 3b, as in the case of approach. For this reason, the reference position detector 6 must be set below the head detection second limit level 6b so that it is turned off before the reference phase (A phase) signal 8 is generated at time t3.

As described above, in the conventional magnetic head positioning mechanism, the setting margin of the reference position detector 6 is extremely narrow, and adjustment is difficult, especially when the positioning interval becomes narrow.

[Purpose of the invention]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a magnetic head positioning mechanism that eliminates the above-mentioned drawbacks of the prior art and allows a wide setting margin for a reference position detector and easy adjustment.

[Summary of the invention]

In order to achieve the above object, the present invention provides a step motor, a driven body driven by the step motor, a reference position detector that detects whether the driven body has reached a reference position, and a reference position detector that detects whether the driven body has reached a reference position. and a logic circuit that outputs a reference position detection signal indicating that the driven body has reached the reference position based on a logic condition consisting of the detection signal of the reference position detector, etc., and continuously monitors the reference position. In the positioning mechanism of the method,
Indicates the moving direction of the driven body (by adding g to the logical condition, the output of the reference position detector is detected only when the driven body approaches the reference position direction, and It is characterized in that it is implanted to prevent erroneous detection of the reference position detection signal that occurs when the body moves away from the reference position.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 3 is a configuration diagram of a positioning mechanism according to an embodiment of the present invention.

The step motor control circuit 3 controls the movement [1 mark signals 3a, 3b] generated by the movement pulse signal 1 and the movement direction signal 2.
is applied to the step motor 4, and a reference phase signal 8 is generated. The reference phase signal 8 is output for each phase number of the step motor 4. The step motor 4 in this embodiment has four phases, and if the phases are named A, B, C, and D, the A phase is the reference phase. The step motor 4 moves the magnetic head 5 based on the applied moving target signals 3a and 3b. The reference position detector 6 detects that the magnetic head 5 approaches the reference position and generates a head detection signal 7. Furthermore, the flip-flop output signal 12 is generated by applying the moving direction signal 2 to the D terminal of the D-type flip-flop circuit 11 and the moving pulse signal 1 to the trigger terminal 1. This flip-flop output signal 1
2, reference phase (A phase) signal 8, and head detection signal 7 are 3.
A reference position detection signal 10 is generated by human-powered AND games 1 to 13. This reference position detection signal 10 is transmitted to the magnetic head 5
indicates that it has been positioned at the reference position, that is, the Baum position, so the output of the movement pulse signal 1 is stopped after the reference position detection signal 10 is detected.

FIG. 4 shows time chart 1 of this embodiment.

When the magnetic head 5 moves in a direction approaching the base i (Q position, that is, when the moving direction signal 2 is "I-bilbel" and a pulse is applied to the moving pulse signal j, the step motor control circuit 3 moves the magnetic head In order to position the magnetic head 5 at the reference position (home position), a movement command such as the movement target signal 3a is given to the step motor 4, but the actual movement of the magnetic head 5 lags behind the movement target signal 3a and does not move as shown in the figure. The movement will be as shown in trajectory 5a.

Here, since the Noritsubu flop output signal 12 of the D-type flip-flop circuit 11 is at the "H" level, the detection signal 7 of the spatula 1 (detection signal 7) is set at the reference point at time t2 in anticipation of a delay in the moving trajectory 5a, as in the conventional case. The head detection lower limit level must be set to 68 or higher so that it turns on before the phase (A phase) signal 8 is generated.

On the other hand, when the magnetic head 5 moves away from the reference position, the flip-flop output signal 12 becomes +r L H level. Therefore, the reference phase (A phase) signal 8 at time t3 is inhibited by the three-man power AND gate 13, and it is possible to prevent the reference position detection signal 10 from being erroneously detected by the reference phase signal 8 at time t3. . Therefore, the setting of the conventional head detection level 6a shown in FIG. 2 is unnecessary.

However, this does not mean that there is no need to provide a bell to the navel 1 only for detection. That is, the new head detection upper limit level of the reference position detector 6 is determined when the magnetic head 5 detects the magnetic head position T4 (the A phase immediately before the A phase corresponding to the reference position, that is, the 7 (θ phase signal) at time t1). It is necessary to consider the case where the magnetic head stops (ends the seek operation) while approaching the reference position at the magnetic head position determined by the output of the reference phase signal 8 at time tl. This is to prevent 10 from being erroneously output.When the seek operation is completed and the transition is to 1-rank following operation, if the magnetic navel 1<5, as shown by the movement trajectory 5c, there will be some initial It moves on a magnetic disk (not shown) accompanied by vibrations.It should be noted that the movement of the magnetic pano 1-5 on the magnetic disk 2 does not mean that the magnetic head 5 actually moves, but rather that the magnetic head 5 itself moves. is stopped on a predetermined trunk space 4, and moves in a circular motion as the magnetic disk rotates.

In consideration of this initial vibration, a new head detection upper limit level 6 has been created.
c is the base output one step before the reference phase corresponding to the reference position! (The position is slightly closer to the reference position than the position determined by phase 0. However, this heno 1 - detection upper limit level 6C
can be set considerably higher than the conventional head detection upper limit level 6b (in the direction away from the reference position), and compared to the setting level of the conventional reference position detector 6.
This provides a large margin and makes adjustment of the reference position detector 6 extremely easy.

〔Effect of the invention〕

According to the present invention, the moving direction signal of the magnetic head is added to the reference position detection logic condition, and the erroneous detection of the reference position signal that occurs when the magnetic head 1 moves away from the reference position can be avoided. By configuring the output of the reference position detector to be detected only when the magnetic spatula 1- approaches the reference position detector, the setting margin of the reference position detector is wide and the magnetic head can be easily adjusted. A positioning mechanism can be realized.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional positioning mechanism, Fig. 2 is a time chart of Fig. 1, Fig. 3 is a block diagram of a positioning mechanism according to an embodiment of the present invention, and Fig. 4 is a time chart of Fig. 3. It is. 3 step motor control circuit, 4 step motor, 5
: Magnetic head, 6: Reference position detector, 12: D type flip-flop, 13: 3 manual AND gate. Fig. 1 Fig. 2 Movement direction signal - 宕2 Time □ Basic position 14 signal 10 Fig. 3 Fig. 4■ Hyperactivity 2%r￥1 9 1st position signal 10

Claims (1)

[Claims] (1) A step motor, a driven body driven by the step motor, a reference position detector that detects whether the driven body has reached the vicinity of a reference position, and a reference position detector that detects whether the driven body has reached a reference position. a logic circuit that outputs a reference position detection signal indicating that the reference position has been reached based on a logic condition consisting of a detection signal of the reference position detector, etc.; , by adding a signal indicating the direction of movement of the driven body to the logical condition, the 21 force of the reference position detector is detected only when the driven body approaches the direction of the reference position, and A positioning mechanism characterized in that the positioning mechanism is configured to prevent erroneous detection of the reference position detection signal that occurs when the body moves away from the reference position.