JPS60115031A - Objective lens driver - Google Patents

Abstract

PURPOSE:To obtain the stable and satisfactory characteristics of an objective lens driver with a simple and thin constitution, by using two means which drive an objective lens supported by an elastic support member capable of displacement in two directions orthogonal to each other in two directions orthogonal to an optical axis. CONSTITUTION:Both ends of an elastic support member 100 containing flat parts 100a and 100b orthogonal to each other and a coupling part 100c are attached to attachment parts 102a and 102b of an objective lens holder 102 as well as to a fixed stage 104. When a coil 105 is energized, an objective lens 101 is driven in the focusing direction with the magnetic force generated between the coil 105 and a magnet 8. While the lens 101 is driven in the tracking direction on the basis of the part 100c when a coil 106 is energized. Thus the lens 101 supported by the member 100 is driven in two directions orthogonal to each other. This reduces the number of manufacturing processes of parts, and no separation is needed between the focusing and tracking parts for assembly. This maintains high accuracy to ensure the stable characteristics of an objective lens driver.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention is applied to an optical recording and reproducing device that optically records information on a disk or optically reproduces information recorded on a disk. The present invention relates to an objective lens driving device.

(B) Prior Art Conventionally, optical recording and reproducing apparatuses for optically recording information on a disk or optically reproducing information recorded on a disk are known. As an objective lens drive device applied to an optical recording/reproducing device, the one shown in FIG. 1 is known.

That is, the objective lens holder (2) to which the objective lens (11 is attached and fixed) is supported by a pair of parallel plate springs (3a) (3b), and the other ends of the plate springs (3a) (3b) are connected to the laser beam. A ring-shaped spring support member (4) in which a light passage hole (4a) and a protrusion (4b) for attaching a bobbin (5) are formed.
) is fixed. Further, an objective lens (1) [i.e.,
A coil /l/(61 is wound around the coil for driving the objective lens holder (2)) in the optical axis direction (focus direction). (71 (81 is the spring support member (4) and the bobbin (5
) is a disk-shaped spring that is attached to the case body (9), and the spring support side (
4) and bobbin (5) are displaceably mounted. (r
or (+ 1 is a yoke attached to each case (9), and a ring-shaped magnet rod is arranged in the middle thereof. Note that the yoke is a damper for suppressing resonance.

When a current is passed through the magnetic circuit consisting of the above-mentioned coil /l/ (61 and magnet θ) [that is, when a current is passed through the coil /L' +61], the magnetic The repulsive force or magnetic attraction force acts to drive the spring support member (4), the object lens (5), and the objective lens (1) in the direction of the optical axis indicated by the arrow in FIG. , focus control of the objective lens (1) is achieved.

On the other hand, the drive 111 in the direction (tracking direction) perpendicular to the optical axis of the objective lens ill is attached to the objective lens holder (
The surface (2) adjacent to the leaf spring mounting surface (2a) (2b) of 2)
c) The magnet θ6) (lQI placed in (2d) and the coil 1 placed in a position opposite to this magnet (1610G+)
This is achieved by the magnetic repulsion force and/or magnetic attraction force that acts between

Note that since the leaf springs (3a) and (3b) are formed in a band shape, they are displaced in the focus direction (optical axis direction) and form a bell shape.

However, in the conventional device with the above-mentioned configuration, (1) the objective lens is supported independently by a tracking spring and a focusing spring, and there are parts intervening between both springs, so it is difficult to install each spring. It is difficult to determine the relative positional accuracy of the focusing spring, and it is difficult to maintain a uniform drive balance in the tracking and focusing directions. (1)) For racking, the tracking spring may not be displaced in the lateral direction correctly even when Since springs and focus springs have many support points and are fixed by adhesive, they require a lot of assembly man-hours, and their installation tends to require a lot of accuracy. Therefore, variations occur in the amount of spring change, frequency characteristics, and sensitivity depending on the product.

(Ill) In order to ensure the desired tracking sensitivity, we use a plate-shaped tracking spring with a thickness of approximately several micrometers, so it does not deform and the two opposing springs are set in an accurate parallel state. It is extremely difficult to
It was not possible to accurately position the objective lens. In addition, since a band-shaped spring that deforms in this way is used, care must be taken when handling it during assembly.Furthermore, since the spring is stored in a case, it is necessary to check if any deformation occurs after assembly. (oV) Since the tracking spring is configured to extend in the optical axis direction, the dimensions of the entire device (especially the height dimension) are large.
Cannot adapt to thinning.

There was a problem.

(c) Purpose of the Invention In view of the above points, an object of the present invention is to provide an objective lens driving device that can obtain stable and good characteristics with a simple configuration and can also be adapted to thinning. shall be.

B) Structure of the Invention In order to achieve the above object, there is provided an objective lens driving device in an optical recording and reproducing apparatus that optically records information on a disk or optically reproduces information recorded on a disk, comprising: A first driving means for driving the objective lens in the direction of the optical axis, a second driving means for driving the objective lens in a direction perpendicular to the optical axis, and two driving means having flat portions orthogonal to each other and at least orthogonal to each other. The objective lens is supported by the elastic support member, and the objective lens is driven by the first or second driving means, so that the objective lens can be moved in two orthogonal directions. It was configured to drive to.

(Example of practical use) 3 and 4 show an embodiment of the present invention.

First, phosphor bronze, nickel silver (Cu + Ni, Zn alloy, Cu 60-65%*Ns 12-22%.

Tubes and cylinders made of alloys containing about 18 to 23% Zn), Be-Cu, stainless steel, etc.

By pressing members such as prismatic rods, flat parts (1ooa) (loob) and connecting parts (10
0c).

Next, an objective lens driving device using the elastic support member (100) will be described.

An objective lens holder (102) to which an objective lens (101) is fixed has an elastic support member (100) attached to a fixing base (104) whose one end is fixed to a base (103).
The other end of 100') (100") is the mounting part (192a) (
102b) supported by being attached to the
The fixing point of the elastic support member (100) (100') (100'') with the fixed base (104) is the fulcrum, and the fulcrum is the arrow direction (focus direction) in FIG. 4(b) and the boundary with the connecting part (100c). 4(a) in the direction of the arrow (tracking direction).

Also, the objective lens holder (2) 0cof lv mounting part (
102c) (102d) is the focus river carp ρ(10
5) is wound, and a frame-shaped tracking coil Iv (106) is fixed on the coil /l/ (105). (107) is a yoke attached to face the base (103), and coils (105) and (106)
A magnet ((108) is disposed at a position opposite to the magnet (108).

In order to perform focus control in the prayer device, when a current is passed through the focusing coil (105) from a servo circuit (not shown), a magnetic repulsive force is generated between the coil/l/(105) magnet (108). Alternatively, a magnetic attraction force acts to drive the objective lens holder (102) (that is, the objective lens (101)) in the direction of the arrow in FIG. 4(b). At this time, the elastic support member (100) is elastically displaced using the fixed portion to the fixed base (104) as a fulcrum.

In addition, in order to perform tracking control, a tracking carp/
When current is passed through l/(106), carp/l/(106)
A magnetic repulsion force or a magnetic attraction force acts on the magnet (108) and the objective lens holder (102) is connected to the flat part (100b) of the elastic support member (100) and the connecting part (100c).
It is driven in the direction of the arrow in FIG. 4(a) using the boundary between the two as a fulcrum.

In addition, when attaching the elastic support member (100) to the fixed base (104), the flat part (100b)
may be attached to the identification stand (104). In this case, the elastic support member (100) is displaced using the boundary between the flat portion (100a) and the connecting portion (100C) as a fulcrum during focus control, and is displaced using the boundary between the flat portion (100a) and the connecting portion (100C) as a fulcrum during tracking control.
00b) is displaced using the fixed point with the identification table (104) as a fulcrum.

By the way, in the objective lens drive device, the spring member that supports the objective lens causes resonance due to its displacement. Since such resonance does not have a negative impact on the recording or reproduction characteristics, it is necessary to attach paulownia wood to suppress the resonance.

Therefore, in the present invention, as shown in FIG. 5(a), the flat part (1
00a) (100b) plate-shaped rubber (109a) (10
9b), or attach tubular rubber (110a) (110b) to flat parts (100a) (10
0b).

FIG. 6 shows another embodiment of the elastic support member, and FIG. 6(a) shows the flat parts (2ooa) (200b
) (200c) and (200d) in a continuous shape, and in FIG. Also, the same figure (c) (d
) ld - mutually orthogonal flat parts (200a) (200b
) (200c) are formed continuously, and a flat part (
200b) into a U-shape.

If such an elastic support member (200) is used to support the objective lens (102) as shown in FIG. 7, the elastic support member (200)
2oo) The number of parts can be reduced from four to two.

FIG. 8 shows still another embodiment, in which the elastic support member (
300), one end of which is formed into a U-shape is used. According to the praying device, a flat part for tracking (
300b) (300b') can be made substantially longer, and the sensitivity of tracking control can be improved.

Note that the end of the elastic support member is attached to the objective lens holder (102
) fixing parts (102a) (102b) (102a') (
102b') and the objective lens holder (
102) has a flat part (300b) during tracking control.
and the U-shaped part (300d) come into contact with the concave part (1o2
f) is formed.

It goes without saying that in all the embodiments described above, the elastic support members are arranged substantially parallel to each other.

Furthermore, in order to correct the fluctuation in the time opening axis direction (jitter direction), a flat portion may be formed perpendicular to the above two directions (focus, tracking).

By the way, the damper member (209) for suppressing resonance is not only attached to a flat part as shown in FIG.
It may be coated as shown in a), or it may be coated with orthogonal flat portions as shown in FIGS. 9(b) and 9(c).

(F) Effects of the Invention According to the present invention, there is provided an objective lens driving device in an optical recording/reproducing apparatus for optically recording disc VC information or optically reproducing information recorded on a disc, which A first driving means for driving the lens in the optical axis direction, a second driving means for driving the objective lens in a direction perpendicular to the optical axis, and two directions having flat portions perpendicular to each other and at least perpendicular to each other. The objective lens is supported by the elastic support member, which is movable to the elastic support member. By driving the objective lens with the first or second driving means, the objective lens is driven in at least two orthogonal directions, which reduces the number of man-hours required for parts processing compared to the conventional method. There is no need to separate and assemble and fix the parts, and since the relative positional accuracy of the flat part is maintained, it is possible to obtain a device with stable characteristics with little variation.

Furthermore, if a plurality of flat portions are formed and the intermediate or one end flat portion is formed into a U-shape, sensitivity can be improved.

The number of parts can be reduced.

Furthermore, by attaching the coil p constituting the second drive means on the coil p constituting the first drive means, it is possible to reduce the size of the drive means as a whole, and the thickness of the entire device can be reduced.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams showing conventional examples, and Figure 3 (,) (b
) are a front view and a perspective view showing an elastic support member applied to the present invention, FIGS. 4(a) and 4(b) are a plan view and a side view showing an embodiment of the present invention, and FIG. Figure 6 (b) is a diagram showing the case where one damper member is attached. Figure (c) ij: side view, Figure 6 (a), (b) (c). )(d) is a diagram showing another embodiment of the elastic support member, FIG. 7 is a diagram showing the main part of the objective lens driving device when the elastic support member of FIG. 6 is used, and FIG. 8(a) (
9b) is a front view of the main part and a partial sectional view of the main part of the main part showing another embodiment, and FIGS. 9(a), 9(b), and 9c are diagrams showing other examples of damper member attachment. (100) (200) (300)... elastic support member,
(101)...Objective lens, (105)...Focusing coil, (106)...Tracking coil, (
108)...Magnet. Fig. 1 Fig. 2 Fig. 7 Fig. 3 ol (bJ Fig. 4 (0) Fig. 5 (0) Fig. 6 200c' Fig. 7 bl e1 09

Claims (1)

[Scope of Claims] +l) An objective lens driving device in an optical recording/reproducing apparatus for optically recording information on a disk or optically reproducing information recorded on a disk, the objective lens driving device being configured to drive the objective lens along the optical axis. a first driving means for driving the objective lens in a direction perpendicular to the optical axis; a second driving means for driving the objective lens in a direction perpendicular to the optical axis; an elastic support member, the objective lens is supported by the elastic support member, and the objective lens is driven by the first mounting mechanism and second driving means,
An objective lens driving device characterized in that the objective lens is driven in at least two orthogonal directions. (2) The objective lens driving device according to claim 1, wherein the elastic support member has flat portions that are orthogonal to each other and are formed alternately and integrally. (3) The objective according to claim 111, wherein the elastic member has a plurality of mutually orthogonal flat portions alternately and integrally formed, and the flat portion at the middle or one end is formed in a U-shape. Lens drive device. (4) The objective lens driving device according to claim 11, wherein a damper member made of rubber or the like is attached to the flat portion. (5) The first driving means includes a coil wound around a holder to which the objective lens is mounted, and the coil/l' constituting the second driving means is mounted on the coil. ) The objective lens driving device described in item 2.