JPS6231038A - Optical system support device of optical pickup - Google Patents

Abstract

PURPOSE:To move an optical system in the direction perpendicular to the optical axis with small force by allowing an intermediate support member supporting the 1st leaf springs which are perpendicular to the optical axis and parallel to each other to rotate by the deformation of the 2nd leaf springs arranged alternately on the same plane. CONSTITUTION:When a focus control current is applied to a focus coil 17, the optical system 11 receives displacement force in the direction of the optical axis and the 1st leaf springs 12a and 12b deform to move the optical system 11 in the direction of the optical axis. When a tracking control current is applied to a tracking coil 18, on the other hand, the optical system 11 receives displacement force perpendicular to the optical axis and the intermediate support member 13 rotates by the deformation of the 2nd leaf springs 14a and 14b to move the optical system 11 at right angles to the optical axis. Consequently, the movement perpendicular to the optical axis is obtained by rotary motion around a support body 15 as a center axis, so the force for the movement is small as compared with conventional constitution and the response is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical system support device in an optical pickup used in an optical disc recording/reproducing device.

[Prior Art] Conventionally, an optical signal detection method is known as one of the methods for obtaining a playback signal from a disk in, for example, a disk playback device. This method uses an optical pickup that emits a laser beam through an optical system onto a rotating disk, detects the reflected light, and converts it into an electrical signal. In addition to sliding in the radial direction, the optical system of the pickup is moved in the track width direction (
It is necessary to displace the optical system in the direction perpendicular to the disk (in the direction of the optical axis) for focus control. Furthermore, although it is necessary to displace the optical system in the track direction of the disk for jitter correction, it is possible to eliminate jitter correction by electrical processing.

In order to displace the optical system of an optical pickup in the optical axis direction and in a direction perpendicular to the optical axis, a conventional optical system support device is constructed as shown in FIGS. 14 and 15. FIG. 14 is a plan view, and FIG. 15 is a front view thereof. That is, the optical system support device supports the optical system 1 and the pair of first
leaf spring 2a.

2b, an intermediate support member 3, a pair of second leaf springs 4a,
4b, and a pair of support bodies 5a, 5b. The optical system 1 has an objective lens 1a housed in a holder. First leaf spring 2a.

2b are arranged perpendicular to the optical axis of the optical system 1 and parallel to each other, one end side is fixed to the optical system 1, and the other end side is fixed to the intermediate support member 3. The second leaf springs 4a, 4b are arranged parallel to the optical axis and parallel to each other, and one end side is fixed to the support bodies 5a, 5b, and the other end side is fixed to the intermediate support member 3.

The supporting bodies 5a and 5b are fixed to the base plate 6. Therefore, the optical system 1 can be moved in the optical axis direction Δ without tilting the optical axis by deforming the first leaf springs 2a, 2b, and the second leaf spring 4a.

By deforming 4b, movement in direction B perpendicular to the optical axis is possible. Note that the displacement force for moving the optical system 1 is obtained by fixing a coil for moving in the optical axis direction (not shown) and a coil for moving in the track width direction (not shown) to the optical system 1. This is provided by arranging a field member (not shown) corresponding to each coil in the vicinity and passing a control current through each coil. A mechanism similar to the structure of the conventional support device described above is disclosed in Japanese Patent Application Laid-Open No. 56-130840. However, in the mechanism disclosed in the publication, the leaf spring for moving in the optical axis direction and the leaf spring for moving in the track width direction are integrally constructed without separately providing the above-mentioned intermediate support member 3.

[Problems to be Solved by the Invention] In the conventional technology, when the optical system 1 is moved in the direction B perpendicular to the optical axis (track width direction), the optical system 1 is displaced in the track width direction. applying force to the optical system 1 and the first leaf spring 2a.

2b and the intermediate support member 3 (or a leaf spring material corresponding to the intermediate support member), it is necessary to move the leaf springs 4a and 4b of the cylinder 2 as a result, and a large displacement force is required. It had The present invention was made in view of the above-mentioned problems, and provides an optical system support device for an optical pickup that can move the optical system in a direction perpendicular to the optical axis with little force. The purpose is to

[Means for Solving the Problems] In this device, the first leaf spring 1 is perpendicular to the optical axis of the optical system 11 and parallel to each other, and one end side is fixed to the optical system 11.
2a, 12b, second leaf springs 14a, 14b which are alternately arranged on the same plane parallel to the optical axis and whose one end side is fixed to the support body 13, and the other end side of the first leaf spring 12a, 12b. and an intermediate support member 15 that supports the other end sides of the second leaf springs 14a and 14b, respectively.

[Function] In this device, the intermediate support member 1 supports the first leaf springs 12a and 12b that are perpendicular to the optical axis of the optical system 11 and parallel to each other.
5 moves the optical system 11 in a direction perpendicular to the optical axis by performing a rotational movement by deforming second leaf springs 14a and 14b arranged alternately on the same plane.

[Example] Hereinafter, the present invention will be described in detail based on the drawings.

1 to 4 show a first embodiment of the optical system support device in the optical pickup of the present invention, and FIG. 1 is an exploded perspective view showing the actuator of the optical system including the support device. Figure 2 is a plan view schematically showing the structure of the support device in Figure 1, Figure 3 is a front view of Figure 2, Figure 4 is a right side view of Figure 2, and Figure 5 is a support device. It is a perspective view showing a main body.

In FIG. 1, reference numeral 11 indicates an objective lens 11 inside the holder.
In this optical system, light is emitted from a laser light source (not shown), passes through a mirror, enters the optical system 11 through an entrance (lower side in the figure), and is emitted upwardly in the figure from the objective lens 11a. A disk (not shown) is placed above the objective lens 11a. As shown in FIGS. 2 and 3, the optical system 11 includes first leaf springs 12a that are perpendicular to the optical axis and parallel to each other.

One end side of 12b is fixed, and the first leaf spring 12a
, 12b are fixed to the upper and lower portions of the intermediate support member 13, respectively. The intermediate support member 11 has a substantially U-shape, and inside thereof second leaf springs 14a and 14b are arranged alternately on the same plane parallel to the optical axis and fixed to the support body 15 at one end. is installed.

The other end side of the second leaf springs 14a and 14b is the intermediate support member 1
It is fixed on the inner side of 3. The support body 15 has a substantially shape as shown in FIG. 5, and as shown in FIG. A spring 14a is connected and fixed, and a second leaf spring 14b is connected and fixed between the lower side of the support body 15 and the other inner surface of the intermediate support member 13. The lower end of the support body 15 is connected to a base plate 16.
Fixed. Therefore, the intermediate support member 13 performs a rotational movement around the support body 15 by the deformation of the second leaf springs 14a and 14b, so that the optical system 11 can be moved in a direction perpendicular to the optical axis. There is. Figures 2 to 4
The support device for the optical system shown in the figure is provided with means for applying a displacement force to the optical system 11, as shown in FIG.

That is, two sets of coils, including a focus coil 17 and a tracking coil 18, are fixed to face each other around the optical system 11.
A part of a field member 24.25 having a magnet 22.23 between the yokes 19, 20, 21 is loosely inserted into the hollow portion of each set of the tracking coil 7 and the tracking coil 18. ing. The lower ends of the field members 24 and 25 are fixed to the base plate 16. Therefore, the focus coil 17 or the tracking coil 18 fixed to the optical system 11
coil 17 or 1 by applying a control 11 current to
8 receives a displacement force within the field members 24 and 25, which biases the optical system 11 in the optical axis direction or in a direction perpendicular to the optical axis.

Next, the operation will be explained with reference to FIGS. 6 to 9.

When a focus control current is applied to the focus coil 17, the optical system 11 receives a displacement force in the optical axis direction, and the optical system 11 moves in a direction parallel to the optical axis due to the deformation of the first leaf springs 12a and 12b. In this case, when the focus control current is in the positive direction, for example, the first leaf springs 12a, 12b are at A as shown in FIG.

direction and moves the optical system 11 in the same direction A1. Further, when the focus control tII current is in the negative direction, for example, the first leaf springs 12a, 12b are bent in the A2 direction as shown in FIG. 7, and the optical system 11 is moved in the same direction Δ2. On the other hand, when a tracking control current is applied to the tracking coil 18, the optical system 11 receives a displacement force in a direction perpendicular to the optical axis, and the intermediate support member 13 rotates due to the deformation of the second leaf springs 14a and 14b. The optical system 11 moves in a direction perpendicular to the optical axis. In this case, when the tracking control current is in the positive direction, for example, the displacement force is transmitted to the intermediate support member 13 via the first leaf springs 12a, 12b, and the intermediate support member 13 moves the second leaf springs 14a, 14b as shown in FIG. Deflect as shown in Figure 4.
It rotates in the rotational direction 81 and moves the optical system 11 in the same direction B1.

Further, when the tracking control current is in the negative direction, for example, the intermediate support member 13 bends the second leaf springs 14a and 14b as shown in FIG. It rotates in the clockwise direction B2 and moves the optical system 11 in the same direction B2.

10 to 12 show a second embodiment of the present invention, and FIG. 10 is a plan view schematically showing the structure of the support device;
1 is a front view of FIG. 10, and FIG. 12 is a perspective view of the support body.

In this embodiment, the second leaf springs 14a and 14b, which are alternately arranged on the same plane and parallel to the optical axis, are constructed so that they can be attached at positions rotated by 90' from those in the first embodiment. It is something. That is, the intermediate support member 13 and the second leaf spring 14a are arranged between the first leaf springs 12a and 12b, which are arranged parallel to each other perpendicularly to the optical axis of the optical system 11 and whose one end side is fixed to the optical system 11. , 14b and the support body 15
The first leaf spring 12a
, 12b is supported by a part of the intermediate support member 13, and the intermediate support member 13 is configured in a frame shape between the first leaf springs 12a and 12b. Then, a second leaf spring 1 is attached to each of the opposing plate portions shown by diagonal lines (cross-sectional portion) in FIG.
4a and 14b are fixed at one end side, and the second leaf spring 14a,
The other end side of 14b is fixed to a support body 15 disposed inside the intermediate support member 13. The support main body 15 has a shape as shown in FIG. 12, and the difference from the main body shape shown in FIG. 5 is that it has a protrusion 15a. As shown in FIG. 10, the protrusion 15a of the support body 15 protrudes from the side surface of the intermediate support member 13 and is fixedly supported by the base plate 16. In this case, the base plate 16 is erected in the optical axis direction.

By configuring as in the second embodiment, the overall length of the optical system support device can be made shorter than in the first embodiment. Furthermore, since the moment of inertia with respect to the center of rotation is reduced, responsiveness is improved. At this time, the optical system 11 is located at a portion opposite to the optical system 11 with respect to the center of rotation of the intermediate support member 13.
It is necessary to attach a weight 31 in order to balance the moment of inertia. Instead of adding the weight 31, the shape of the intermediate support member 13 may be changed to maintain balance.

In the second embodiment, when assembled, the second leaf springs 14a are arranged on the same plane parallel to the optical axis.

In order to facilitate the fixed connection between 14b and the support body 15,
First leaf springs 12a, 12b perpendicular to the optical axis and parallel to each other
A hole of an appropriate size may be provided in the hole. By providing the holes in the first leaf springs 12a and 12b in this way, the lower end of the support body 15 can be fixed to the lower base plate through the hole in the leaf spring 12b. The shape shown in Figure 5) can be used. Also, instead of providing holes in the first leaf springs 12a, 12b, each of the first leaf springs 12a, 12b is divided into two thin strip-shaped leaf springs, and a total of four leaf springs are used. A configuration may also be used.

In addition, 1st. In both the second embodiment, three or more second leaf springs may be arranged parallel to the optical axis and on the same plane. The second leaf spring is composed of a single S-shaped leaf spring 14 having two spring deformation parts as shown in FIG.
The bent portion may be fixed in correspondence with the bent portion of the support body 15. This one leaf spring 14
The shape can also be configured to have three or more spring deformable parts other than the fixed part (bending shape part).

[Effects of the Invention] As described above, according to the present invention, by using a configuration in which leaf springs are alternately arranged on the same plane parallel to the optical axis of the optical system, Since the movement in the desired direction is achieved by rotational movement about the support body as the central axis, the force for movement is less than in the conventional structure, resulting in flow and good responsiveness.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of an actuator including an optical system support device of an optical pickup according to a first embodiment of the present invention, and FIG. 2 is a plan view schematically showing the configuration of the support device of FIG. 3 is a front view of FIG. 2, FIG. 4 is a right side view of FIG. 2, FIG. 5 is a perspective view of the support body of FIG. 2, and FIGS. FIGS. 8 and 9 are explanatory diagrams for explaining the operation in the optical axis direction of the first embodiment. FIG. 10 is an explanatory diagram for explaining the operation in the direction perpendicular to the optical axis of the first embodiment. FIG. 11 is a partially cutaway front view of FIG. 10, FIG. 12 is a perspective view of the support body of FIG. 10, and FIG. 13 is a first embodiment. and a front view showing another example of the second leaf spring shown in the second example,
FIG. 14 is a plan view showing a conventional optical system support device, and FIG.
The figure is a front view of FIG. 14. 11...Optical system, 11a...Objective lens, 1
2a, 12b--First leaf spring, 13--Intermediate support member, 14a, 14b--Second leaf spring, 15--Support body, 16--Base plate. Figure 1 Figure 7 Figure 8 0. 0 Susu Lee-Shu-Kou Procedure Ner11jEp1 (self-motivated) 1. Indication of matter A11 1985 patent application No. 1708
96@2, Title of the invention Optical system support device 3 in an optical pickup, person responsible for correction f Figure 18)-Sleep

Claims (1)

[Claims] An optical system support device for an optical pickup that supports an optical system for irradiating a signal writing or signal reading light beam onto a disk surface so as to be movable in the optical axis direction or in a direction perpendicular to the optical axis. a pair of first lenses that are perpendicular to the optical axis, parallel to each other, and one end of which is fixed to the optical system;
a pair of second leaf springs, which are arranged alternately on the same plane parallel to the optical axis and whose one end side is fixed to the support body; An optical system support device for an optical pickup comprising intermediate support members that respectively support the other end sides of leaf springs.