JPH0244336Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a support structure for supporting a movable part in an information reading device.

In an information reading device, a disk (recording medium)
A movable part including an optical system that illuminates the recording surface of the disc with a spot light for reading information is fixed to a predetermined base via a support member made of an elastic material, and the spot light is accurately focused on the track of the disc. It is driven in the focus direction (i.e., the direction perpendicular to the disk), the tracking direction (i.e., the radial direction of the disk), and the tangential direction (i.e., the direction in which the disks are connected to the tracks) by a plurality of drive mechanisms provided around the disk. Ru.

In such a support structure for a movable part, by exhibiting the vibration characteristics of a single resonance system, a constant amplitude band occurs below the resonance frequency, so that the amplitude sensitivity below the resonance frequency, that is, the low frequency sensitivity decreases. Also,
Since it is supported by a support member so that it can vibrate and swing in the focus direction, tracking direction, and tangential direction, the position of the center of swing relative to the optical system changes significantly as the position of the optical system in the focus direction changes. There is a drawback.

An object of the present invention is to provide a support structure for an information reading device that reduces the decrease in low frequency sensitivity due to the influence of a single resonance system and reduces changes in the center of oscillation with respect to the optical system.

The support structure according to the present invention supports the movable parts of the optical system that irradiates the recording surface of the recording medium with a spot light for reading information and the plurality of drive mechanism parts that drive this optical system against a predetermined base using a support member. It is configured to be slidably held by a swingably supported sliding guide.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a side sectional view of an information reading device equipped with a support structure according to the present invention, and FIG. 2 is a top view thereof. In the figure, reference numeral 1 denotes a pickup incorporating, for example, a semiconductor laser (not shown), which focuses irradiated light from the laser onto the recording surface of a disk (recording medium) 2. pick up 1
For example, there are four drive mechanism parts 3a, 3 around the pickup 1 in order to drive the pickup 1 in the focusing direction, the tracking direction and the tangential direction.
b, 3c and 3d are arranged. The pick-up 1 is attached to the holding member 4 so as to be located equidistant from the drive mechanism parts 3a to 3d.

In each of the drive mechanism sections 3a to 3d, a magnetic circuit 9 is formed by a yoke 6 fixed to a base 5, a magnet 7 erected on the yoke 6, and a pole piece 8 fixed on the upper surface of the magnet 7. ing. A bobbin 11 fixed to the four corners of the lower surface of the holding member 4 via a member 10 and a drive coil 12 wound around the bobbin 11 are positioned within the gap of the magnetic circuit 9. As shown in FIG. 3, the positional relationship of these drive mechanism sections 3a to 3d is such that the track direction indicated by arrow 13 and the line connecting the centers of drive mechanism sections 3a and 3c coincide with each other, and are perpendicular to this arrow 13. The drive mechanism parts 3b and 3d are arranged so that the lines connecting the centers of the drive mechanism parts 3b and 3d coincide with each other, or the lines connecting the track direction and the centers of the drive mechanism parts 3a and 3b and the drive mechanism part 3 are aligned.
They are arranged so that the lines connecting the centers of c and 3d are parallel. And these drive mechanism parts 3a to 3
The pickup 1 can be driven in the focus direction, tracking direction and tangential direction by appropriately combining the drive signals applied to each drive coil 12 of d.

The pick-up 1 is held by a cylindrical sliding guide 14 so as to be slidable in its optical axis direction, that is, in the focus direction. The sliding guide 14 is swingably supported by a support member 15 relative to the base 5. The support member 15 is fixed to the base 5 by a stopper 16. Support member 15
As shown in a plan view and a side sectional view in FIGS. 4A and 4B, respectively, the outer edge 15a is fixed to the base 5, and the inner edge 1 holds the sliding guide 14.
5b, and for example, four bent, preferably bellows-shaped connecting parts 15c connecting the outer edge part 15a and the inner edge part 15b, and between each of the four connecting parts 15c, there is, for example, a substantially circular shape. hole 15d
is formed. Outer edge 15a, inner edge 15b
The connecting portion 15c is integrally formed with a plastic such as thermoplastic polyester elastomer, which can be molded three-dimensionally and into a thin spring shape, and is integrally formed by injection molding of this plastic. There is.

In this configuration, when no external force is applied to the pickup 1 itself, it is held in a predetermined position by the sliding guide 14, and as shown in FIG. When a driving force in the direction is applied, it slides against the sliding guide 14. At this time, the sliding guide 14 and the holding member 4 sometimes come into contact with each other, and the supporting member 15 does not deform much. Further, when a driving force in the tracking direction or the tangential direction is applied to the pickup 1, the holes 15d formed between the connecting portions 15c in the support member 15 and the connecting portions 15c
By working together, complex deformation is possible, and this allows it to respond to the swinging of the pickup 1.

As described above, according to the present invention, the vibration in the focus direction is dealt with by the sliding guide, and the vibration in the tracking direction and the tangential direction is dealt with by the support member, so that a single resonance system can be used. It is possible to reduce the decrease in low frequency sensitivity due to the influence of the vibration, and also to reduce the change in the center of swing when the pickup swings. Furthermore, since there is no need to fix the pick-up and the supporting member, work such as adhesion is eliminated, and cost reduction and reliability improvement can be expected due to improved workability. Furthermore, since the movable range of the support member is small, its design becomes easier and the device can be made smaller. Furthermore, if some abnormality occurs and the pick-up suddenly moves toward the disk, the supporting member's elastic performance as a single resonance system increases the force that prevents it as the pick-up approaches the disk. It also has the effect of preventing the pickup from colliding with the disk, or acting as a so-called damper to cushion the collision of the pickup and protect the disk.

In addition, in the above embodiment, the drive mechanism section is
Although the description has been given of a configuration in which only one person is used, the configuration is not limited to this, and it goes without saying that a configuration in which three people are used, for example, can also be applied. Further, the optical system driven by the drive mechanism is not limited to a semiconductor laser pickup, and may be only an objective lens or only a part of the optical system.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of an information reading device equipped with a support structure according to the present invention, FIG. 2 is a top view thereof, FIG. 3 is a diagram showing the positional relationship of the drive mechanism, and FIGS. 4A and B are support structures. A plan view and a side sectional view showing an example of the member,
FIG. 5 is an operational diagram for explaining the operation of FIG. 1. Explanation of the symbols of the main parts, 1... Pick up,
2...Disk, 3a-3d...Drive mechanism section, 6
... Yoke, 7 ... Magnet, 12 ... Drive coil, 14 ... Sliding guide, 15 ... Support member,
16...stopper.

Claims (1)

[Claims for Utility Model Registration] (1) A cylindrical body containing an optical system for illuminating the recording surface of a recording medium for reading information is slidably supported, and the peripheral portion is supported by a predetermined base. a cylindrical sliding guide whose one end is supported at the center of a flexible support member; and a driving force that is attached to the cylindrical body via a holding member and that acts independently in the optical axis direction by electromagnetic action. and a plurality of drive mechanism parts that generate the cylindrical body, and the cylindrical body is driven in the optical axis direction and in the direction orthogonal to the optical axis by an appropriate combination of the driving forces generated by these drive mechanism parts. A supporting structure in a featured information reading device. (2) The support member has an inner edge portion that holds the sliding guide, an outer edge portion that is fixed to the predetermined base, and a number of bent drive mechanism portions that connect the inner edge portion and the outer edge portion. A support structure for an information reading device according to claim 1, characterized in that the support structure comprises a plurality of connecting portions corresponding to the above. (3) The support structure for an information reading device according to claim 2, wherein the inner edge portion, the outer edge portion, and the connecting portion are integrally molded from plastic.