JPS62241184A - Head position deviation reducing device - Google Patents

Abstract

PURPOSE:To decrease the position deviation of a magnetic head due to the vibration attended with the carrying of the device by short-circuiting the coil of a step motor at power interruption so as to utilize a counter electromotive force. CONSTITUTION:Since relay derive circuits 7, 8 are not activated at the interruption of power, relays 5, 6 are not driven and switches 5a, 6a are closed respectively. The vibration is fed to the rotary shaft 2 of the step motor 1 via a head carriage, an arm and a band actuator attended with the carrying of the device. Since the coils 3a, 3b and 4a, 4b are short-circuited, the counter electromotive force is generated to the rotation of the rotary shaft 2 to suppress the rotation of the shaft 2. Thus, the position deviation of the magnetic head is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a head misalignment reducing device used in a device that reduces the misalignment of a magnetic head from a predetermined position due to impact or the like during movement of a disk drive device or the like.

BACKGROUND OF THE INVENTION Conventionally, in floppy disk drive devices and fixed disk drive devices, in order to prevent the magnetic head from moving during movement, the shock of the magnetic head carriage has been absorbed using a cushioning material such as styrofoam.

Problems to be Solved by the Invention However, with the above-mentioned conventional head position misalignment reducing device, although large shocks can be absorbed by the cushioning material, since the cushioning material such as Styrofoam has elasticity, it cannot absorb even minute vibrations. could not. Therefore, if the magnetic head on the media deviates by a value smaller than the minimum travel distance of the step motor that moves it, correction from the host computer side will be impossible, and the entire magnetic head will deviate from the correct position of the media track. There was a problem when a reading error occurred. To correct this read error, the drive had to be disassembled and readjusted.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, it is an object of the present invention to provide an excellent head position deviation reducing device that reduces reading errors caused by minute vibrations.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention is configured such that the coils of the step motor are connected to each other when the power source is turned on.

Operation According to the present invention, with the above-described configuration, the minute movement of the magnetic head that occurs due to vibration of the entire device when the power is turned off can be reduced by the back electromotive force of the coil.

Embodiment FIG. 1 is a circuit diagram of a head position deviation reducing device according to an embodiment of the present invention, and FIG. 2 is a perspective view showing an example of use of this embodiment.

In Figures 1 and 2, 1 is a step motor with two-phase bidirectional excitation of 0.9 degrees/step, 2 is the rotating shaft of the step motor, 3a, 3b is a set of coils, 4a, 4b
is a set of coils. 5 is a set of coils 3a, 3b
This reed relay short-circuits the 5
When the power is turned on, the relay drive circuit 7 outputs a drive signal to the drive terminal 5b to open the switch 5a. When the power is turned off, the switch 5a is closed. 6 is a set of coils 4a,
When the power is turned on, the reed relay 6 outputs a drive signal from the relay drive circuit 8 to the drive terminal 6b to open the switch 6a. When the power is turned off, the switch 6a is opened.

9 is a coil drive circuit that inputs signals to the coils 3a, 3b, 4a, and 4b to rotate the rotating shaft 2.

10 is a control circuit that controls the coil drive circuit 9.

11a and llb are band actuators that convert the rotation of the rotary shaft 2 into circular motion; 12 is an arm that performs circular motion; 13 is a rotary shaft that rotates due to the circular motion of arm 12;
14 is a head carriage; 15 is a magnetic head for magnetically recording and reproducing information on and from a medium 16;

Reference numeral 17 denotes a foot that houses reed relays 5, 6, relay drive circuits 7, 8, coil drive circuit 9, control circuit 10, and the like.

Next, the operation of this embodiment will be explained.

In Figures 1 and 2, when the power (+12 yen) is turned on, the relay drive circuits 7 and 8 are operating, so the relay 5
, 6 to drive the switch 5a.

6a are opened respectively. Therefore, the control circuit 10
The signal is sent to the coil/' 3a via the coil drive circuit 9.
It is input to l 3b, 4a, and 4b, and controls the rotation of the rotating shaft 2. The rotation of the step motor 1 is the rotating shaft 2-
Band actuator Ila, 1lb-arm 12
, the rotating shaft 13, and the head carriage 14 to move the magnetic head 15 to a desired position on the medium.

On the other hand, when the power supply (+12V) is cut off, the -relay drive circuit 7,
8 is not operating, relays 5.6 are not driven and switches 5a, 5a are each closed.

Here, when this device is moved and vibration is applied to the arm 12 etc., the vibration will cause the band actuator
b, is applied to the rotating shaft 2 via lla.

However, since the coils 3a, 3b and 4a, 4b are connected to each other, the rotation axis of the rotating shaft 2 causes the coil 3
A back electromotive force is generated between a and 3b and 4a and 4b, and a rotational force is applied in a direction that reverses the rotation of the rotating shaft 2. Therefore, the force applied to the single-rotation shaft 2 is caused by the positive rotational force from the arm 12 and the reverse rotational force from the coils 3a, 3b, 4a, and 4b simultaneously canceling each other out - as if a brake had been applied to the single-rotation shaft 2. As a result, the rotation shaft 2 does not rotate at all.

Therefore, when the power is turned off, even if vibration force is applied to the arm 12, the back electromotive force of the coils 3a to 4b will cause the magnetic head 15 to
No minute movement occurs.

Effects of the Invention As is clear from the above-mentioned embodiments, the present invention is configured such that the coils of the step motor are connected to each other when the power is turned off, so that minute movements of the magnetic head caused by vibrations of the entire device are reversed by the coils. It has the effect of being able to be reduced by electromotive force.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a head position reducing device according to an embodiment of the present invention, and FIG. 2 is a perspective view of the same embodiment. 1...Step motor, 2...Rotating shaft, 3at3J
4a-+4b...Coil, 5.6-...Reed relay, 7,8...Relay drive circuit, 9...Coil drive circuit-10...Control circuit.

Claims (1)

[Claims] A step motor that rotates in steps by applying a pulse to an excitation coil, a switch means that connects the excitation coil when the power is turned off, and an actuator means whose rotation is controlled by the step motor, and the actuator means rotates when the power is turned off. 1. A head position deviation reducing device, characterized in that, even if vibration is applied to the actuator, movement of the actuator means is reduced by a back electromotive voltage of the excitation coil.