SU1345252A1 - Device for positioning magnetic heads - Google Patents

Abstract

This invention relates to a magnetic recording technique. The purpose of the invention is to improve the accuracy and speed of installation of magnetic heads on the carrier track. The device contains a stepping motor 1, a yoke 3, carriages 5,6, magnetic heads 7 and 8, a ruler 9, a photosensor 10, a photodetector 11, a diaphragm 12, a source 13 of light, a piezodvigator 14, a plate 16, a spring 17, a control circuit 19 control, consisting of a microprocessor 20, a motor control unit 21 of the motor 1, a vibration converter control unit 22 and a track number counter 23. The introduction of a new element and the formation of new connections between the elements of the device makes it possible to reduce the resistance forces to movement during operation of the electric motor 1. Piezoelectric motor 14 generates high-frequency ones; fluctuations, thereby excluding the forces of dry friction in kinematic pairs. 1 il. (L 1 i SAE Nj SL 1C SP GcE

Description

113

The invention relates to a magnetic recording technique, namely to stepper drives for the movement of magnetic heads, and can be used in magnetic disk drives.

The purpose of the invention is to improve the accuracy and speed of installation of the magnetic heads on the carrier tracks.

The drawing shows a block diagram of the proposed device.

The device contains a reversive stepper motor 1, the shaft 2 of which is connected to the yoke 3, equal-lever lever 4, the opposite ends of which are connected to the carriages 5 and 6, on each of which magnetic heads 7 and 8 are rigidly fixed through the holders 4 9a on the rocker arm 3 - a photosensor 10 with a photo receiver 11, a diaphragm 12 and a light source 13. A piezodigital 44 is attached to the carriage 6, which through the concentrators 15 abuts against the plate 16 and through the compression springs 17 to the base 18. The control circuit and control 19 consists of an MfiKpon processor 20, a control unit for a stepper motor 21, a control unit for the vibrator and a reversible counter 23 for the track number.

The stepper motor control unit includes a low frequency generator

pulses, a switchboard distributor and an amplifier, and a vibrator converter control unit consists of a sinusoidal oscillator, an electronic key that controls the reverse of the vibrator transducer.

The device works as follows.

Before installing the magnetic heads 7 and 8 on the selected information tracks of the magnetic disk (not shown in the figure), a command from the microprocessor 20 via the control unit of the stepper motor 21 is started in a predetermined direction by a stepper motor 1, which through the shaft 2, the rocker arm 3 and the lever 4 sets the magnetic head 7 or 8 to the information path prescribed by the microprocessor 20. A predetermined number of spent discrete steps by a stepping motor is controlled by a reversing counter 23 of the track number and, when specified by the microprocessor 20, the counter content is

but zero, a signal is output to the control circuit to stop the stepper motor 1. The stepper motor 1, through shaft 2, rocker arm 3, lever 4 and carriage 5 and 6, positions magnetic heads 7 and 8. Additional micro-movement of table coordinates is performed by a command from the microprocessor 20, through the control unit 22, the piezomotor 14 is turned on. The piezo actuator 14 through the hubs 15, the plate 16 moves the magnetic head 8, and through the lever 4 and the carriage 5 the magnetic head 7 moves to the center of the information track, which Yedelev a photosensor 10.and raster line 9 to high. positioning accuracy. When changing the micro-movements of the piezoelectric motor 14, the block circuit 21 reduces the current in the phase of the electric motor, in order to reduce the resistance forces of the movement, i.e. reducing the load on the piezomotor.

When a stepper motor is in operation, the law of transformation of the rotational movement of the shaft 2 into the translational movement of the coordinate tables 5 and 6 of the Cartesian coordinates is expressed through the equations

Have

Where

 2RR

cos 9

- radius of the crank; 9 - angle of rotation of the crank; X and y are the linear displacements of the coordinate tables 5 and 6, respectively, from the initial position. During the operation of a piezomotor, the dependence of displacements on a micromeasurement is expressed by

 4R.y-y2

Yy

To reduce the resistance to movement during the operation of a stepper motor, a piezomotor generates high-frequency ones: oscillations, so as to exclude the dry friction forces in the key pairs of mathematics. This makes it possible to increase the switching frequency of the phases of the stepping motor and thereby increase the speed of positioning.

Claims (1)

Invention Formula A magnetic head positioning device comprising a set31345252 The carriage in the housing with the holder head, the transfer mechanism of the semi-magnetic head, reversible jnaro-ny in the form of rocker arm, one end of the kovy electric motor, the second mechanism is connected to the shaft of the step electric motor and the piezomotor, distinguishes the rotor, and the other - with equal arm e so that, with the aim of a higher lever, the ends of which attach precision and speed are positioned to the carriages, and the piezoelectric motor dioning, it has been supplemented with a surface of one of the coaxial carriage with a magnet-retok holder. Compiled by S. Karpenkov Editor I. Segl nikTehred A. Kravchuk Proofreader A. Zimokosov Order 4926/50 Circulation 587 Subscription ZNKZHSH USSR State Committee for inventions and discoveries 113035, Moscow, 5K-35, Raushsk nab., 4/5 " Aro-production-poly graphic enterprise, Uzhgorod, Projecto st., 4