SU1644216A1 - Head for optical presentation of information - Google Patents

Description

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(21) 4684436/10 (22) 02.23.89 (46) 04.23.91. №15 (71) Research Institute of Household Electronic Equipment {72) MVKravets. I.Ya.Kokovsky, I.Ya. Shcherbaty and V.Shchur (53) 681.84.083 (088.8) (56) Application of EPO G 0176332, c. C 11 V 7/12, 1985.

(54) HEAD FOR OPTICAL REPRODUCTION OF INFORMATION

(57) The invention relates to an information accumulation technique and can be used for a two-coordinate

positioning the lens in optical video playback devices or audio information from a disk recording medium. The purpose of the invention is to increase the vibration protection and positioning accuracy of the head while simplifying its design. For this, the axis 1 is rigidly connected to the frame 5 of the movable part and is mounted by pins 9 in the supports 10 of an elastic suspension, made in the form of flat springs 3 and fixed on the housing 4. On the housing 4 there is also installed an inductive damping coil 8, magnetically interacting with the counterweight 7 in as a permanent magnet. 1 hp ff, 2 ill.

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The invention relates to an information accumulation technique and can be used for two-coordinate positioning of a lens in video optical playback devices. audio information from disk recording media.

The aim of the invention is to increase the vibration resistance and positioning accuracy of the head while simplifying its design.

FIG. 1 shows a simplified diagram of the head; in fig. 2 - constructive execution of the head.

Head contain 1 {fig. 1) the movable part 2 connected by flat springs 3 with the body 4. The mobile part 2 consists of a frame 5 carrying the lens 6, which is balanced by a counterweight 7, the counterweight being made of a permanent magnet and has the possibility of magnetic interaction with the field of the damping coil 8, mounted on the housing 4.

Axis 1 is connected to the press-fit frame 5 and is installed with conical pins 9 in wear-resistant, for example, stone supports of flat springs 3. Focusing coil 11 of the focus actuator (Fig. 2) and the radial tracking drive coil inductance 2 heads. The head housing 4 consists of a base 16, magnets 17 and 18, and a magnet & wires 19-22 for focusing magnets 23-26 of a radial tracking actuator mounted on brackets 27-30, respectively. The inductive damping coil 8 is mounted on the bracket 31, while the magnetic cores and the brackets are made in one piece with the base 16 and form the rom magnetic system.

The frame 5 has through-holes 32 in which the focusing actuator cores 19 and 20 are included. The dimensions of the holes allow for relative movement of the movable part of the head within the limits sufficient to perform radial tracking and focusing operations.

The dotted line shows the installation directions of the parts.

The focus actuator magnets 17 and 18 are magnetized in the direction of the optical axis of lens 6, and the radial tracking actuator magnets 23-26 are magnetized in the direction perpendicular to the winding plane of the inductance coils 12-15.

The length of axis 1 is much longer than the distance between the flat springs 3 of the assembled head, which leads to the head

deflection of flat / ix springs, the value of which should exceed the working stroke of the movable part of the head in the direction of the optical axis. In this case, due to the elastic forces of the initially bent springs, reliable contact is achieved between the conical axles 9 of the axis 1 and the supports 10, eliminating the presence of a gap in the slip pair. The magnitude of the frictional forces arising from

The 0 rotations of the trunnions 9 of the axis 1 of the moving part of the head and the supports 10 should be reduced by reducing the flexural rigidity of the springs.

Flat springs attached to body 4

5, with the ability to adjust the position of the wear-resistant supports 10 in a plane-perpendicular optical axis, it is 6, which makes it possible to correct small deviations of the direction of the optical axis relative to the recording medium (not shown).

Solovka works as follows. When a focusing drive inductance 11 (Fig. 2) is applied to the kagushka 11, its magnetic field is guided by a magnetic field, interacting with magnetic fields of magnets 17 and 18, moves the movable part of the head with lens 6 along the optical axis, overcoming the elastic forces of flat springs 3 the direction of decreasing the focusing error by an amount proportional to the focusing error.

When fed to the coils 12-15 of the induction of the drive of an oedial tracking of the control signal, its magnetic field, interacting with the magnetic field of magnets 23-26, rotates the moving part of the head with the lens 6 around the axis

0 1 in the direction of reducing the radial tracking error by an amount proportional to the collision rad | / сл01 о tracking.

When the drive focuses, the oscillations of the movable part 2 of the head along the optical axis are damped by elastic flat springs 3.

Hps / i operation of the radial tracking drive system, torsional vibrations of the moving part 2 of the head around axis 1

0 is damped due to the interaction of the magnetic field: the damping inductive coil 8, mounted on the bracket 31, with the counterweight 7 of the permanent magnet mounted on the frame 5 of the movable

5 parts. The required accuracy of the radial positioning of the head is achieved by adjusting the damping coefficient of the torsional vibrations by varying the strength of the current flowing in the winding of the damping coil.

Claims (1)

Claim 1. A head for optical reproduction of information comprising a housing equipped with an electromagnetic two-lord drive of a lens and a movable part including a frame with an object and a counterweight, the movable part being connected to the body through elastic elements and an axis characterized in that , in order to increase the vibration protection and positioning accuracy of the head while simplifying its design, s has introduced an inductive damping coil located on the body with the possibility 0 the magnetic interaction with the counterweight of the movable part, made in the form of a permanent magnet, the axis is made with conical axles, and the elastic elements are made as a pair of parallel flat springs with wear-resistant supports, in which a conical axle axle is mounted. rigidly connected to the frame. 2, a head according to claim 1, characterized in that the wear-resistant supports are mounted with the possibility of an adjustable movement from a plane perpendicular to the optical axis of the lens. ten 18 FIG. 2