JPH04178923A - Optical system drive device - Google Patents

Abstract

PURPOSE:To obtain a device which has less deterioration, is small, is light, has good frequency characteristics, and can be controlled easily by constituting a support means by using an elastic bar member in which vibration damping material is held or filled, as a support means. CONSTITUTION:A vibration-damping member is put into a hollow part of a cylindrical elastic body consisting of a spring material whose section is nearly rectangular etc. in support members 21a - 21c. A substance with a vibration- damping property such as a macromolecular chemical compound material where butyl rubber, silicon rubber, oil, or a vibration-damping plastic, and elastomer agent are added can be sued as a vibration-damping material. Therefore, the vibration-damping material is in contact with an elastic member efficiently, thus obtaining a device which has a good frequency characteristics although it is light, can be controlled easily at high-speed operation, and has less deterioration of performance since no vibration-damping materials are stucked.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an optical system drive device suitable for, for example, an optical information recording/reproducing device.

[Prior Art] Conventionally, when recording information on an information recording medium such as an optical disk, or when reproducing or erasing recorded information, a light beam emitted from a semiconductor laser light source is formed into a minute spot with a diameter of about 1 μm. An information recording and reproducing device that narrows down and irradiates the recording surface of an information recording medium is often used. The optical system driving device of such information recording and reproducing devices usually has focusing control to correct out-of-focus caused by surface wobbling of the information recording medium, and optical beam control to correct defocusing caused by eccentricity of the information recording medium. A drive device is provided for performing tracking control to correct positional deviation of the spot, and this drive device is entirely mounted on a carriage and performs a seek operation to coarsely move on the information recording medium.

Figure 1O shows a configuration diagram of a conventional optical system drive device, in which coils 3.3 are attached to the left and right sides of a carriage 2, which is movably supported back and forth by two parallel rails 1 and 1, and a coil 3.3 is attached to the main body of the device. is driven in the theta direction parallel to the rails 1 and 2 by the electromagnetic force acting between the yoke 4.4 fixed to the substrate of and the permanent magnet 5.5 attached to the inner surface of the yoke 4.4. It looks like this. A relay member 6 is provided above the carriage 2, and a parallel leaf spring 7.7 with its surface facing vertically extends from the front and rear surfaces of the relay member 6 in the horizontal direction. , four parallel leaf springs 8 with their surfaces oriented in the horizontal direction are extended, and the parallel leaf springs 8
A lens holding member IO is attached to the tip of a parallel plate spring 9.9 which extends further from each tip and whose surface is oriented in the vertical direction. A circular through hole 10a is provided in the center of the lens holding member 10 in the vertical direction, and an objective lens 11 with its optical axis directed in the vertical direction is fixed within the through hole 10a. Rectangular holes 10b and l are provided on both the left and right sides of the hole 10a.
oc is formed in which inner yokes 12a, 12a are arranged. A focusing coil 13 is wound around the lens holding member 10, and two tracking coils 14 are attached to the left and right sides of the lens holding member 10 in a row. A permanent magnet 15 is provided on the side surface of the tracking coil 14, and this permanent magnet 15 is attached to the outer yoke 12.
b, and the outer yoke 12b is fixed to the tracking coil 1.
4.14, is connected to the inner yoke 12a, and is further bonded onto the carriage 2.

In this case, since the focus coil 13 crosses the magnetic field between the permanent magnet 15 and the inner yoke 12a, when a current is passed through the focus coil 13, a vertical force acts, and the 4
The parallel leaf springs 8 are bent, and the objective lens 11 is displaced in the optical axis direction. Furthermore, the same magnetic flux is applied to tracking coil 1
4.14, the tracking coil 14.
When the current of 14 is different between the front and back, a force in the front and back direction acts, the parallel leaf springs 7.7 and 9.9 are bent, and the objective lens 11 is displaced in the tracking direction.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional example, the parallel leaf springs 7 to
Since the resonance peak at the natural frequency of 9 and the peak at multiple resonance points are high and have a negative effect on the electric servo of the optical system drive device, a rubber or plastic plate material with distributing properties is bonded to the parallel leaf springs 7 to 9. to dampen vibrations. In this method, it is necessary to surround the leaf springs 7 to 9 with a damping material, which not only increases the weight of the optical system drive device (complicates the assembly process), but also tends to cause adhesive deterioration over time or the environment.

The purpose of the present invention is to eliminate the above-mentioned drawbacks, reduce deterioration, and
An object of the present invention is to provide an optical system driving device that is small, lightweight, has good frequency characteristics, and is easy to control.

[Means for Solving the Problems 1] In order to achieve the above-mentioned object, in an optical system driving device according to the present invention, the optical system driving device has a supporting means for movably supporting an objective lens. It is characterized in that it is constituted by a rod-shaped elastic member that is gripped or filled with a substance having a damping material.

[Function] In the optical system drive device having the above configuration, the damping material is in reliable contact with the elastic member constituting the support means, so the frequency characteristics are good even if the support means is lightweight. Because it is held without twisting, deterioration is less likely to occur.

[Example] The present invention will be explained in detail based on the example illustrated in FIGS. 1 to 9. Note that the same reference numerals as in FIG. 10 represent the same members.

FIG. 1 shows a configuration diagram of the first embodiment, in which a carriage 2 is movably supported back and forth by two parallel rails 1.1.
The yoke 4. has coils 3.3 attached to its left and right sides and is fixed to a substrate of the information recording/reproducing apparatus main body (not shown).
4. The fact that the yoke 4.4 is driven in the theta direction parallel to the rail 1.1 by the electromagnetic force acting between the yoke 4.4 and the permanent magnet 5.5 attached to the inner surface of the yoke 4.4 is shown in FIG. This is the same as the conventional example. Further, a relay member 6 is provided on the carriage 2, and support members 21a, 21a each having a plate-like outer shape are jutted out laterally from the front and rear sides of the relay member 6 with their surfaces facing each other. Four plate-shaped support members 21b, 21b whose surfaces are oriented in the horizontal direction extend from above and below the tips of the support members 21b, 21.
A plate-shaped support member 21c extends from the tip of b with its surface facing in the vertical direction, and holds the lens holding member IO at the tip. As shown in FIG. 2, the support members 21a to 21c have damping material 23 filled in the hollow part of a cylindrical elastic body 22 made of a spring material or the like and having a substantially rectangular cross section. As the material 2, materials having vibration damping properties such as butyl rubber, silicone rubber, oil, vibration damping plastics, and polymeric chemical composites to which an elastomer agent is added can be used. Further, the rest of the structure of the relay member 6 is the same as that of the conventional example shown in FIG. 1O.

Since the focus coil 13 crosses the magnetic field between the permanent magnet 15 and the inner yoke 12a, the focus coil 1
3, a vertical force acts and the support member 21b
is bent, and the objective lens 11 is driven in the optical axis direction. In addition, the same magnetic flux passes between the poles of the tracking coils 14 and 14, and when the currents in the front and rear tracking coils 14 are different, a force in the front and rear direction acts, bending the support members 21a and 21c, and moving the objective lens 11 in the tracking direction. driven by. Then, resonance due to the restoring force of the elastic body 22 of the support members 21a to 21c and the mass of the lens holding member 1O is caused by the damping material 2.
3, and since the damping material 23 is securely in contact with the inner surface of the elastic body 22, the damping effect is large.

Note that the shape of the supporting members 21a to 21c does not have to be a closed cross section as shown in FIG. 2, and as shown in FIG. The body 25 is rolled (folded into a substantially cylindrical shape), the fourth
As shown in the figure, a damping material 24 is sandwiched between elastic bodies 26 with a U-shaped cross section, and as shown in FIG. 5, a damping material 27 with an L-shaped cross section has three bent parts. Plate-shaped elastic body 28
Alternatively, as shown in FIG. 6, a damping material 29 having a substantially trapezoidal cross section may be held from the long base side of the trapezoid by a plate-shaped elastic body 30 having two bent parts.

Alternatively, the supporting members 21a to 21c may have a cylindrical shape with no directionality, and a damping material may be placed inside. That is, FIG. 7 shows a pipe-shaped elastic body 31 filled with or inserted with a damping material 32, and FIG. 8 shows a cylindrical damping material 33 wrapped around an elastic body 34. .

FIG. 9 shows a support member 40 made of two spring materials whose holding part is movable only in the vertical direction, and four support members 41 having the same U-shaped cross section as shown in FIG. 4 are used. and
A damping material 43 is sandwiched inside each elastic body 42, and the objective lens 11 is supported movably only in the vertical direction by bending the support member 41.

In the above examples, all of the damping materials are held in close contact with the inner surface of the elastic body without adhesion, so there is no reduction in damping performance due to deterioration of the adhesion, and the material is lightweight and has damping performance. expensive.

In the above-described embodiment, the lens holding member IO is movable in two directions, focusing and tracking, but it may be implemented in an optical system drive device configured to only be capable of focusing.

[Effects of the Invention] As explained above, in the optical system drive device according to the present invention, since the damping material efficiently contacts the elastic member, the frequency characteristics are good even though it is lightweight, and control in high-speed operation is easy. Yes, there is little deterioration in performance because the damping material is not bonded.

[Brief explanation of drawings]

Drawings 1 to 9 show an embodiment of the optical system driving device according to the present invention, in which FIG. 1 is a configuration diagram, FIG. 2 is a configuration diagram of a support member, and FIGS. 3 to 8 are diagrams of a support member. A configuration diagram of another embodiment of
FIG. 9 is a block diagram of another embodiment of the support means, and FIG.
The figure is a configuration diagram of a conventional example. 2 is a carriage, 6 is a relay member, 10 is a lens holding member, 11 is an objective lens, 12a is an inner yoke, 12b is an outer yoke, 13 is a focus coil, 14 is a tracking coil, 15 is a permanent magnet, 21a to 21c, 40.4
1 is a support member. 22.25.26.28.30.31.34.42 is an elastic body, and 23.24.27.29.32.33.43 is a damping material. Patent applicant Canon Co., Ltd. Figure 1

Claims (1)

[Claims] 1. An optical system drive device having a support means for movably supporting an objective lens, characterized in that the support means is constituted by a rod-shaped elastic member gripped or filled with a substance having a damping material. .