JPH01251438A - Actuator for optical pickup head - Google Patents

Abstract

PURPOSE:To attain miniaturization, light weight, and low power consumption by driving a first regulation member whose one end is fixed on a base and a supporting part regulated by a second regulation member to be connected via a connection part by corresponding driving mechanisms, respectively. CONSTITUTION:The horizontal flat springs (20-23) of the regulating member in the focusing direction of an objective lens whose one end is fixed on the base and the vertical flat springs 30 and 31 of the regulation member in a tracking direction are coupled with the connection part 24, and the supporting part of the objective lens 33 is mounted via the springs 30 and 31. And the driving of the supporting part in the focusing and the tracking directions are performed by a first driving mechanism 29 and a second driving mechanism 38, respectively. By employing constitution in which the driving mechanism is bi-sected, the actuator miniaturized and with low power consumption can be obtained.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) This invention projects a light spot onto an information track that records digital signals at high density, such as a CD or LV (laser vision). The present invention relates to an actuator for an optical pickup head that writes and reads information.

(Prior Art) An actuator for an optical pickup head is used as a device for moving a light spot in two axial directions (focusing and tracking directions) by following the surface wobbling and warping of an optical disk. Figures 6 and 7 show the actuator of a conventional optical pickup head, with a magnet 1.2
A coil 4. is included in the magnetic circuit composed of a yoke 3.3a and a yoke 3.3a.
A bobbin 7 wound with a material 5.
Alternatively, it is driven only in the focus direction.

Further, the inner yoke 11.12 is inserted into an opening 9.10 provided inside the bobbin 7, so that the magnetic circuit is closed.

Further, the bobbin 7 is elastically supported by four support rods 13, - 15, and as these four support rods 13, - 15 are twisted together, the bobbin 7 is moved in the focusing direction and the tracking direction. is now moving.

The optical pickup head configured in this manner includes a coil 4 for generating a driving force in the focusing direction, and a coil 5.6 provided outside of this coil 4 for generating a driving force in the tracking direction. are doing. The coil 4 in the focusing direction and the coil 5 in the tracking direction are provided between the magnet 1 and the bobbin 7 so as to overlap each other.

Similarly, a coil 4 in the focusing direction and a coil 6 in the tracking direction are provided between the magnet 2 and the bobbin 7, which are symmetrically provided, so that they overlap.

A movement space 16.17 is provided between the magnet 1.2 and the tracking coil 5.6 facing the magnet 1.2 when the magnet 1.2 moves in the two directions.

For this reason, if the coils 4.5.6 for driving in two axial directions are provided in an overlapping manner, a large moving space 16.17 is required, and the coil 5.6 and the magnet 1.
2, the power consumed to obtain a predetermined driving force increases and the actuator itself becomes larger.

On the other hand, as CD5LVs become smaller and more portable, optical pickup heads are desired to be improved in the direction of smaller size, lighter weight, and lower power consumption (higher output).

(Problem to be Solved by the Invention) As mentioned above, in the conventional structure, a bobbin having an objective optical system and a magneso!・Two coils for driving in the focus direction and tracking direction are provided so as to be overlapped between the two coils, and the bobbin itself is arranged between the two coils.
Since they are driven simultaneously in the axial direction, a large amount of movement space is required. For this reason, a large amount of power is consumed to drive the bobbin, and the device itself becomes large.

This invention was made in view of the above-mentioned circumstances, and aims to provide an actuator for an optical pickup head that is smaller, lighter, and consumes less power, and that satisfies the currently required performance. .

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a base with one end of a first elastic body having a free direction in one of the focusing direction and the tracking direction, and a connecting portion at the other end of the first elastic body. established,
A first drive mechanism is provided to drive the connecting portion in the one direction, and one end of the second elastic body having a free direction in the other direction of the focusing direction or the tracking direction is provided,
A support part is provided at the other end of this second elastic body, an objective optical system is provided in this support part, and a second part that drives the support part in the other direction is provided.
An actuator for an optical pickup head is provided with a drive mechanism.

(Function) First and second elastic bodies each having free directions in the focusing direction and the tracking direction are independently provided, and first and second drive mechanisms each driving in the two axial directions are provided respectively. By setting it up independently,
The travel space is reduced, thereby reducing the number of turns required in the coil to obtain the required driving force.

(Example) Hereinafter, a first example of the present invention will be described with reference to FIG. The actuator 18 of the optical pickup head shown in the figure is fixed to the base (not shown) by the protrusion 1.
are connected through one. This fixing convex portion 19 has a first
One end of four horizontal leaf springs 20, - 23 as elastic bodies are connected to each other. These four horizontal leaf springs 2
Two horizontal leaf springs 20.21 are separated from the other two horizontal leaf springs 22.23 by a predetermined distance. are arranged in parallel. These horizontal springs 20. ~23
is elastically deformed only in the focus direction indicated by arrow A.

Further, a connecting portion 2 is provided at the other end of the horizontal leaf springs 20, 23.
4 are integrally connected. This connecting portion 24 is formed in a rectangular shape, and the horizontal plate springs 20 are attached to the four corners of the connecting portion 24.
~23 are combined.

In other words, the connecting portion 24 is elastically supported only by the four horizontal leaf springs 20, 23.

An insertion portion 25 is formed in a substantially central portion of the connecting portion 24 and extends vertically through the insertion portion 25, and a focus coil 26 is inserted into the insertion portion 25.

This focus coil 26 has a communicating portion in the vertical direction.
It is wound into a rectangular tube shape.

One end of a yoke 27 having a concave cross-sectional shape H is loosely inserted into the cylindrical opening of the focus coil 26. A magnet 28 is coupled to the surface of the other end of the yoke 27 facing the focus coil 26, and the lower surface is coupled to the base to constitute a first drive mechanism 29.

Furthermore, two vertical springs 30.
31 are connected to each other at one end. Here, the vertical leaf springs 30, 31 are elastically deformed only in the tracking direction indicated by arrow B. At the other end of these vertical leaf springs 30, 31 there is a support 1'! The j section 32 is connected. An objective lens 33 serving as an objective optical system is provided at the center of the support portion 32. Here, the support section 32 is configured to move only in the I-racking direction with respect to the connection section 24.

Further, a rectangular through hole 34 passing through the support portion 32 in the vertical direction is formed on the distal end side of the support portion 32, and an eyeglass-shaped tracking coil 35 is attached to the distal end surface corresponding to the through hole 34. ing.

One end of a yoke 36 formed in a concave shape is inserted into the through hole 34, and a magnet 37 is coupled to the other end facing the tracking coil 35. 2 drive mechanism 38 is tIXs
has been completed.

Because of this, the support structure and drive mechanism that moves in the focus direction are
It is composed of horizontal leaf springs 20, - 23 as elastic bodies and a first drive mechanism 29.

Further, the support structure and movement mechanism for movement in the tracking direction are constituted by vertical leaf springs 30, 31 as second elastic bodies and a second drive mechanism 38.

In other words, the coils 26.35 that are driven in the focusing direction and the tracking direction are provided in different parts, so that the coils 26.35 in the same two directions are no longer provided in an overlapping structure, and can be driven independently. Since it is provided, the movement space can be made more compact. Further, by reducing the moving space, the same driving force as in the conventional case can be obtained even if the number of turns of the coil 26.35 is reduced.

Further, horizontal leaf springs 20, ~23 and vertical leaf springs 30
．． 31, each end of which is connected by a connecting portion 24, and parallel leaf springs 20, 23, 30 between the fixed convex portion 19 of the base (not shown) and the support portion 32 of the objective lens 33.
．． 31 is elastically deformed sequentially from the proximal end to the distal end, so the movement space required for each drive mechanism 29, 38 can be reduced. That is, since it moves only in two directions, there is no need for space for movement in diagonal directions as in the conventional case, and the magnet 28.37 and coil 26.35 can be provided close to each other. By providing the magnet 28.37 close to the coil 26.35 in this way, it is possible to obtain the same driving force as before with a small number of turns of the coil 26.35, resulting in lower power consumption and lower power consumption. It can also be made smaller and lighter.

A second embodiment of the present invention will be described below with reference to FIGS. 2 and 3. The actuator 39 of the optical pickup head shown here is provided with a fixing protrusion 4 in the approximate center of a base 40, and the fixing protrusion 41 is provided with two horizontal leaf springs 42 as first elastic bodies. One end of the .43 is connected.

Here, the horizontal leaf springs 42 and 43 are provided vertically apart from each other, and a connecting portion 44 is coupled to the other end.

A focus coil 45 is coupled to the distal end side of the connecting portion 44, and one end of a yoke 46 having a concave cross section and whose bottom portion is coupled to the base 40 is loosely inserted into the focus coil 45. , the same focus coil 45
A magnet 47 is coupled to the side surface of the other end corresponding to the outer surface of the magnet 47, thereby forming a first drive mechanism 48.

Further, one ends of vertical leaf springs 49,50, which serve as second elastic bodies, are respectively coupled to the connecting portion 44 so as to be located on both sides of the horizontal leaf springs 42,43.

Both of these vertical leaf springs 49 and 50 are provided in parallel, and a support portion 51 is coupled to the other end. An objective lens 52 as an objective optical system is provided approximately at the center of the support portion 51, and a rectangular through hole 53 is formed at the tip thereof in the vertical direction. 5
An eyeglass-shaped tracking coil 54 is attached to the distal end surface corresponding to No. 3. Further, one end of a concave-shaped yoke 55 whose bottom part is connected to the base 40 is loosely inserted into the through hole 53, and the tracking coil 55 is inserted into the other end.
A second drive mechanism 57 is configured by combining a magnet 56 facing the magnet 4 with the magnet 56 .

By doing (+y) in this way, the same effect as in the first embodiment can be obtained.

A third embodiment of the present invention will be described below with reference to FIGS. 4 and 5. The actuator 58 of the optical pickup head in this embodiment has fixed protrusions 60 and 61 provided on the left and right sides of one end of the base 59. One end of a vertical leaf spring 62, 63 as a first elastic body is coupled to each of these fixed protrusions 60, 61. These vertical leaf springs 62 and 63 are connected at a predetermined slope so that their tips are close to each other, and a connecting portion 64 is connected to the other end. A through hole 65 is formed in the vertical direction in this connecting portion 64, and one end of a yoke 66 is loosely inserted into this through hole 65. Further, a tracking coil 67 is attached to the distal end surface of the connecting portion 64 corresponding to the through hole 65, and this tracking coil 6
7 faces the other end of the yoke 66, and a magnet 68 is coupled to this opposing surface to form a first drive mechanism 69.

Further, two horizontal leaf springs 70.71 as second elastic bodies are located at the center of the proximal side surface of the connecting portion 64 and are vertically spaced apart between the vertical leaf springs 62.63. One end is joined.

A support portion 72 is coupled to the other end of the horizontal leaf spring 70, 71. An objective lens 73 as an objective optical system is provided in the center of the support portion 72, and a focus coil 74 is coupled to the end surface on the distal end side, and one end of a yoke 75 is connected to the focus coil 74. A magnet 76 facing the focus coil 74 is connected to the other end of the yoke 75 which is loosely inserted, and a second drive mechanism 77 is connected.
(:14 has been completed.

With this configuration, effects similar to those of the first and second embodiments can be obtained.

〔Effect of the invention〕

By providing separate elastic bodies and drive mechanisms in the focus direction and tracking direction, it is possible to achieve a reduction in size and weight, and to reduce power consumption.
It is possible to provide an actuator for an optical pickup head that can be easily made portable for applications such as (laser vision).

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a first embodiment of the invention, FIGS. 2 and 3 are a second embodiment of the invention, FIG. 2 is a plan view of an optical pickup head, and FIG. 3 is a perspective view of a second embodiment of the invention. The cross-sectional view taken along the line ■-■ in the figure, FIGS. 4 and 5 are the third embodiment of the present invention, and FIG. 4 is a plan view of the optical pickup head, and FIG. 6 and 7 are conventional examples, and a perspective view of the ^th optical pickup head. FIG. 7 is a sectional view of the section taken along the line ■--■ shown in FIG. It is. 20, to 23... horizontal leaf spring (first elastic body), 24
...Connection part, 29...First drive mechanism, 30°'3
1... Vertical leaf spring (second elastic body), 32... Support [1
j section, 33... Objective lens (objective optical system), 38...
Second drive mechanism. Attorney Takehiko Suzue Figure 1 Figure 3

Claims (1)

[Claims] a first elastic body having one end coupled to the base and having a free direction in one of the focusing direction and the tracking direction; a connecting portion provided at the other end of the first elastic body;
a first drive mechanism that drives the connecting portion in the one direction;
A second portion having one end coupled to the connecting portion and having a free direction in the other of the focusing direction or the tracking direction.
an elastic body, a support provided at the other end of the second elastic body, an objective optical system provided on the support, and a second drive mechanism that drives the support in the other direction. An actuator for an optical pickup head, comprising: