JPS6153773B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a support device for an electromechanical transducer for vibrating an optical system having at least one lens in three-dimensional space.

Optical reproducing devices that use laser light focus the laser light on a minute spot to detect signals, but in order to read the signal correctly, the light spot must be adjusted according to the irregularities and vibrations of the information recording carrier. Focusing control for focusing on the information recording carrier and tracking control for ensuring that the light spot always follows the correct signal track are required. Furthermore, if a time base error occurs due to uneven rotation or eccentricity of the information recording carrier, control for correcting this error is also required. In order to perform these controls, an error detection device that detects each error and an actuator that moves the optical system to cancel out the errors are essential. Various methods have been devised for error detection devices, but they will be omitted here.

In conventional actuators, as shown in, for example, Japanese Patent Publication No. 14611/1983, a two-stage combination of leaf springs that can bend only in one direction is used as a support device. However, with this configuration, the driving force in the focusing direction is transmitted to the objective lens via the tracking leaf spring, which tends to cause unnecessary resonance phenomena, and the reaction force generated in the tracking leaf spring when driven in the tracking direction Since it is transmitted to the fixed part via the focus plate spring, resonance is also likely to occur and control is difficult.

Further, in the configuration shown in Japanese Patent Publication No. 109801/1983, eight L-shaped springs, each of which is a rod-shaped spring bent at right angles, are used as a support device for the actuator. However, in this L-shaped spring, when one side of the L-shape is bent, the other side is twisted. For this reason, flexural vibration and torsional vibration coexist, causing a coupled vibration, resulting in a disadvantage that a complex resonance phenomenon occurs. When a metal material is used for the L-shaped spring, a large resonance phenomenon occurs, and when a soft material is used, static positioning is difficult.

Further, as an example of a system in which a viscoelastic body is used as a support device, there is one shown in FIG. In FIG. 1, 1 is a driven body including electromagnetic means such as a coil, 2 is a frame, and 3-1 to 3-8 are supports made of viscoelastic bodies. However, in this configuration, when a driving force due to an external magnetic field is applied to the driven body 1 in an axial direction parallel to the support body 3, the deformation of the support body 3 causes bending in addition to expansion and contraction in the axial direction, and the driven body 1 has the disadvantage that it also includes components of motion other than in the axial direction. for example,
FIG. 2 shows an example of a state in which a driving force in an axial direction (x-axis direction) parallel to the support body 3 is applied to the driven body 1. The supports 3-1 and 3-4 are bent in addition to compressive deformation in the x-axis direction, and the shape of the deformation exists in other ways and cannot be uniquely determined, so it is difficult to control the movement of the driven body 1. It is difficult.

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art, eliminate unnecessary resonance phenomena, easily perform focusing control, tracking control, and time base control, and furthermore, eliminate the optical axis inclination associated with focusing control and tracking control. is to provide support equipment for small electromechanical transducers.

The present invention uses a plurality of supports made of a viscoelastic body processed into an elliptical ring shape or an arc shape, one end of each support member is fixed to a driven body, the other end is fixed to a holding part, and the driven body is driven. It is characterized in that the support is supported so that when force is applied, the deformation of the support is mainly a change in its curvature.

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 3 is a plan view showing the configuration of the first embodiment of the present invention. Although the driven object 1 is simplified in the figure, it is equipped with electromagnetic means such as coils for driving in three orthogonal directions and an optical system having at least one lens, and is equipped with an optical system having at least one lens. generates driving force. Support body 4-1
4-4 are made by processing a viscoelastic material such as rubber into an elliptical ring shape, and one of the two longitudinal parts of each is fixed to the driven body 1 and the other to the frame 2. The fixed parts of the support body 4 on the side of the driven body 1 are arranged at two locations in each of two mutually parallel planes that cross the driven body 1, and the fixed parts on the frame 2 are also arranged on two mutually parallel planes. There are two locations inside.

With such a configuration, the driven body 1
Since the support body 4 is a soft viscoelastic body, it can move freely no matter which direction the support body 4 receives a driving force from its rest position. For example, in FIG. 4, the driven body 1 is x
This figure shows the deformation state of the support body 4 when receiving a driving force in the axial direction. The support body 4 mainly changes only its curvature compared to the resting state, and the deformation is uniquely determined, and the fixed parts of the support body 4 are in two mutually parallel planes, so it is difficult to drive. Since the degree of freedom of the body around the three mutually orthogonal axes is suppressed, the driven body 1 is displaced only in the x-axis direction in which it receives the driving force, and is only displaced in the other two mutually orthogonal axes. does not change. Also,
Similarly, when receiving driving force in the other two axial directions, the driven body 1 is displaced only in the axial direction. in this way,
No matter which direction the driven body 1 moves, the deformation that the support body 4 undergoes is mainly bending, so that unnecessary resonance phenomena are unlikely to occur. Furthermore, among the six degrees of freedom that the driven body 1 has, the degrees of freedom around the three axes that are orthogonal to each other are suppressed, and since it actually has degrees of freedom only in the three orthogonal axes directions, the If the optical axis of the optical system to be used coincides with one of the three axes, the optical axis will not be tilted. Therefore, the design of the optical system included in the driven body 1 becomes easy.

FIG. 5 is a plan view showing the structure of a second embodiment of the present invention. This is an example in which eight arc-shaped viscoelastic bodies are used as supports. In this embodiment as well, the deformation of the support body 5 is mainly a bending in which the curvature changes no matter which direction the driven body 1 moves in response to the driving force, and the support body 5
Since the fixed parts of are located in two planes parallel to each other, the degrees of freedom around the three mutually orthogonal axes are suppressed, so the driven body 1 has degrees of freedom only in the three axes, and is unnecessary. Resonance phenomena are unlikely to occur.
Therefore, the use of this support 5 can facilitate the manufacture of the support without changing the functionality compared to the case where the elliptical ring-shaped support 3 described above is used.

FIGS. 6 and 7 show an example in which supports 6 and 7 having substantially the same shape as the arc-shaped support 5 described above are used and supported by changing their arrangement. It is something that

FIG. 8 is a needle perspective view of a combination of a drive device for driving in three orthogonal directions and a support device according to the present invention, and FIG. 9 is an exploded perspective view of the configuration. The driven objects are an optical system 8, an optical system holder 9, drive coils 10-1 to 10-4 in the x direction, and y
It is composed of drive coils 11-1 to 11-4 in the direction, drive coils 12-1 to 12-4 in the z-axis direction, and coil holders 17-1 and 17-2. Frame 13 has yoke 14-1 to 14-6, 15-
1 to 15-6 and magnets 16-1 to 16-
A magnetic circuit constituted by 6 is fixed. The driven body is supported from the frame 13 by supports 4-1 to 4-4 made by processing a viscoelastic body into an elliptical ring shape so that the drive coils 10, 11, and 12 are correctly arranged in the magnetic gap. be done. With such a configuration, driving forces in three orthogonal directions can be obtained, and the effects of the present invention described above can be obtained.

As described above in detail with reference to the embodiments, according to the present invention, since an elliptical ring-shaped or arc-shaped viscoelastic body is used for the support, unnecessary resonance phenomena are less likely to occur, and the manufacturing of the support and the electric machine The converter is easy to assemble. Further, since the fixed portions of the support bodies are located in planes parallel to each other, the degree of freedom in the rotational direction of the driven body is suppressed, and the driven body moves only in two or three orthogonal axes directions. Therefore, the design of the optical system becomes easy, and a compact and low-cost electromechanical transducer can be realized.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a conventionally used support device, FIG. 2 is a plan view showing its deformed state, FIGS. 3 and 4 are plan views showing an embodiment of the present invention and its deformed state, 5 to 7 are plan views showing other embodiments of the present invention, and FIG. 8 is a perspective view showing an embodiment in which a support device according to the present invention and a drive device are combined in three mutually orthogonal directions. , Figure 9 is the 8th
FIG. 2 is an exploded perspective view of the configuration of the illustrated embodiment. 1: driven body, 2: frame, 3 to 7: support body, 8: optical system, 9: optical system holder, 10: x drive coil, 11: y drive coil, 12: z drive coil, 13: frame, 14: Upper yoke, 15:
Lower yoke, 16: magnet, 17: coil holder.

Claims (1)

[Claims] 1. A driven body comprising electromagnetic means such as a plurality of coils or magnets for driving in three directions orthogonal to each other and an optical system having at least one optical lens, and a corresponding electric signal. A support device for an electromechanical transducer that provides vibrational displacement in each direction by using a plurality of viscoelastic bodies processed into an elliptical ring shape as a support body, the curvature of the elliptical ring changing as the driving body is displaced, A support device for an electromechanical transducer, wherein the deformation of the support body results in a change in curvature. 2. The supporting body is fixed in one of two longitudinal directions to the driven body and the other to the holding part, and the fixed part is fixed in two parallel planes crossing the driven body and in two parallel planes to the plane. 2. The electromechanical transducer support device according to claim 1, wherein the device is disposed within two planes of the holding portion that are at equal distances from the plane. 3 A driven body comprising electromagnetic means such as a plurality of coils or magnets for driving in three mutually orthogonal directions and an optical system having at least one optical lens is vibrated in each direction by a corresponding electric signal. In a support device for an electromechanical transducer that provides displacement, a plurality of viscoelastic bodies are processed into an arc shape and whose curvature changes as the driving body is displaced, and the deformation of the support body is caused by the curvature. A support device for an electromechanical converter characterized by a change in 4. Fixing a part of the supporting body to the driven body and fixing the other part to the holding part, and fixing the fixed part in two parallel planes that cross the driven body and in the plane parallel to the said plane. 4. The electromechanical transducer support device according to claim 3, wherein the electromechanical transducer support device is disposed in two planes of the holding portion that are at equal distances from each other.