JPH11167735A - Objective lens driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an objective lens driving device in which the objective lens is hardly inclined to an optical disk at the time of moving a movable part in the directions parallel with the optical axis and orthogonal to the optical axis. SOLUTION: The passing holes 23a-23d of wires 7a, 7b of a connecting substrate 9 and a fixed substrate 11 are made to be a taper shape in the longitudinal direction of the wires. Otherwise, the diameters of the wire passing holes 23a-23d are made larger than the diameter of a hole of a terminal plate. Moreover, the diameters of the wire passing holes 23a-23d and the diameters of holes of the terminal plates 34a-34d are continuously made to be the taper shape in the longitudinal directions of the wires 7a, 7b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an objective lens driving device used for an optical disk device.

[0002]

2. Description of the Related Art In an optical disk apparatus, light emitted from a light source such as a semiconductor laser is focused on an optical disk by an objective lens. Conventionally, an objective lens driving device that moves the objective lens in a direction parallel to the optical axis of the objective lens and in a direction perpendicular to the optical axis has been used. The objective lens driving device drives and displaces the objective lens in a direction parallel to the optical axis and in a direction perpendicular to the optical axis in accordance with the focusing error signal and the tracking error signal, thereby recording a signal on the disk accompanying the rotation of the disk. The light irradiated through the objective lens is focused on a predetermined signal recording surface of the disk, following the surface runout, the meandering and eccentricity of the signal track. An example of an objective lens driving device used in such an optical disk device is described in Japanese Patent Application Laid-Open No. 8-263860.

[0003]

In recent years, there has been a tendency to use an objective lens having a large numerical aperture in order to improve the recording density of an optical disk device. Therefore, strict accuracy is required for the relative angle shift amount between the objective lens and the disk.

In the conventional objective lens driving device described in the above publication, a movable portion composed of an objective lens, a bobbin, a focusing coil, a tracking coil and the like is cantilevered on a fixed portion via an elastic support member, and ,
A magnetic circuit including a yoke and a magnet is provided on the fixed portion side. The elastic support member is made of a conductive material. One end of the elastic support member is a focusing coil,
And it is electrically connected to the tracking coil via a terminal plate. Further, the other end of the elastic support member is fixed to a terminal plate of the substrate attached to the fixing portion with a conductive adhesive such as solder.

A focus coil via an elastic support member,
When an electric current is applied to the tracking coil, the electric current flows in a magnetic flux created by a magnetic circuit constituted by a yoke and a magnet, and a force for displacing the movable portion is generated. With this force, the movable part moves in a direction parallel to the optical axis of the objective lens and in a direction perpendicular to the optical axis. In the conventional objective lens driving device described in the above-mentioned publication, a total of four elastic support members are disposed, one pair on the left and right sides of the movable portion, that is, two upper and lower portions on one side. When the movable portion is moved, the fulcrum of the movable portion side and the fixed portion side of these elastic support members are shifted, so that the left and right, up and down intervals of the elastic support members, and the length of each elastic support member are further reduced. Vary. For this reason, there is a problem that the inclination of the objective lens when the movable section is moved in a direction parallel to and perpendicular to the optical axis of the objective lens becomes large. In addition, there is a problem that extremely high assembling accuracy is required in order to reduce the displacement of the mounting position of the elastic support member and suppress the inclination of the objective lens.

[0006]

In order to solve the above-mentioned problems, an objective lens driving device according to the present invention includes a movable portion including an objective lens and a bobbin holding the objective lens, a fixed portion, and one end. The movable part is attached to the substrate held by the fixed part at the other end, and the movable part is supported movably in a direction parallel to the optical axis of the objective lens and in a direction perpendicular to the optical axis of the objective lens. A plurality of elastic support members are provided, and the holes provided through the elastic support members provided on the substrate are configured to increase in diameter in the extending direction of the elastic support members.

[0007] In one embodiment of the invention, the holes are configured in a conical shape. Further, a substrate for fixing one end of the elastic support member is attached to the movable portion, and a hole through which the elastic support member penetrates is provided in the substrate, and the hole of the substrate is formed in the extending direction of the elastic support member. It is configured so that the diameter becomes larger toward it. Preferably this hole is configured in a conical shape. Alternatively, the substrate attached to the fixed portion has a conductive terminal plate held on the surface opposite to the extending direction of the elastic support member, and the terminal plate has a hole through which the elastic support member passes. The hole and the hole of the substrate are arranged concentrically, and the diameter of the hole of the substrate is larger than the diameter of the hole of the terminal plate.

Further, a conductive terminal plate is held on the surface of the substrate attached to the bobbin on the surface opposite to the extending direction of the elastic support member, and the terminal plate has a hole through which the elastic support member penetrates. And the holes are arranged concentrically with the holes in the substrate, and the diameter of the holes in the substrate is larger than the diameter of the holes in the terminal plate.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the objective lens driving device according to the present invention will be described in detail using some examples.

[0010]

FIG. 3 is a perspective view showing the basic structure of an objective lens driving device. FIG. 4 is a plan view of the objective lens driving device of FIG. 3 as viewed from above. FIG. 5 is a side view showing the objective lens driving device of FIG. 4 from the direction of arrow c. 3, 4 and 5, an objective lens 1 is mounted on a bobbin 2, and a focusing coil 3 is arranged at the center of the bobbin 2. The focusing coil 3 is formed of an air-core coil having a rectangular cross section, and is fixedly adhered to the bobbin 2. Further, in order to generate the driving force in the focusing direction, the magnet 5 and the yoke are arranged so that the longitudinal component 3a of the focusing coil 3 is sandwiched and a magnetic flux acts on the longitudinal component 3a substantially at right angles. 4
Are arranged. A pair of tracking coils 6 is attached to the surface of the longitudinal component 3a of the focusing coil 3.

In the objective lens driving device shown in FIGS. 3, 4 and 5, the movable portion comprises an objective lens 1, a bobbin 2, a focusing coil 3, a tracking coil 6, and the like. On the other hand, the fixed part is provided with the fixed substrate 11 on the holder 8.
Is attached, and the holder 8 is fixed to the yoke 4 by screws 12. The movable portion is cantilevered by the fixed substrate 11 of the fixed portion via elastic support members 7a to 7d (hereinafter abbreviated as wires), and a magnetic circuit including the yoke 4 and the magnet 5 is provided on the fixed portion side. It has a configuration. The wire 7 is made of a conductive material. In this embodiment, the holder 8 is also called a gel box, and the space portion through which the wires 7a to 7d pass is filled with gel. The fixed substrate 11 is fixed to the side surface of the holder 8, but may be fixed to the yoke 4. In any case, the fixed substrate 11 only needs to be fixed to a fixed portion including the yoke 4, the holder 8, and the like.

FIG. 5 is a partial cross-sectional side view of the vicinity of the wire attachment position of the movable portion and the vicinity of the wire attachment position of the fixed portion for clarifying the wire attachment state. In order to support the bobbin 2 by four wires 7a and 7b (two of the four wires are not shown in the drawing), two connection substrates 9 integrally attached to the bobbin 2 are provided.
Are provided with four holes 13a and 13c through which one ends of four wires 7a and 7b respectively penetrate (two of the four wire passage holes are not shown in the drawing). (In the embodiment of the present invention, this hole is provided for passing a wire serving as an elastic support member, and hence is hereinafter referred to as a wire passage hole for convenience.) That is, the wire passage hole 1
3a and 13c are provided in parallel with each other in pairs. Further, terminal plates 14a and 14c for connecting conductive wires extending from the coil ends of the focusing coil 3 and the tracking coil 6 are formed around the periphery where the wire passage holes 13a and 13c are provided. One end of each wire 7a, 7b is connected to the wire passage hole 13a, 13c.
To the connection board 9 by a conductive adhesive such as a solder 10 applied to the terminal boards 14a and 14c.
Fixed to The electrical conduction between the wires 7a and 7b made of a conductive material and the terminal plates 14a and 14c is achieved by the solder 10, and therefore, the focusing coil 3 and the tracking coil 6 connected to the terminal plates 14a and 14c are provided. Is electrically conducted between the conductive wire of the first and second wires 7a and 7b. The other ends of the wires 7a and 7b are connected to the terminal plates 14b and 14d of the fixed substrate 11 attached to the fixed portion.
Then, it is fixed with solder 10 like the movable part side.

When a current is applied to the focusing coil 3 and the tracking coil 6 via the wires 7a and 7b, the current flows in a magnetic flux created by a magnetic circuit formed by the yoke 4 and the magnet 5, so that the movable portion is displaced. Force is generated. With this force, the movable part moves in a direction parallel to the optical axis of the objective lens 1 (the direction of arrow a in FIGS. 3 and 5) and in a direction perpendicular to the direction (the direction of arrow b in FIGS. 3 and 4).

FIGS. 6 and 7 are sectional side views showing the positional relationship between the wires and the substrate. FIG. 6 shows the connection board 9 on the movable section shown in FIG. 5, the terminal boards 14a and 14c, the wires 7a and 7b attached to the connection board 9, the fixed board 11 on the fixed section, and the fixed board 11. Terminal board 14 to be attached
Only b and 14d are shown extracted. The upper wire 7a is connected to the wire passage hole 13a of the connection board 9 on the movable portion side.
Further, it is fixed through substantially the center of the wire passage hole of the terminal plate 14a, the wire passage hole 13b of the fixed substrate 11 on the fixed part side, and the wire passage hole of the terminal plate 14b. On the other hand, the lower wire 7b is fixed in a state shifted from the center of the wire passage holes 13c and 13d. This means that during assembly
This is because the relative positions of the wires 7b and the connection board 9 and the fixed board 11 are shifted.

Now, assuming that the connection between the wires 7a and 7b and the connection board 9 and the fixed board 11 is fixed as shown in FIG. 6, the connection board 9 is moved in the direction of arrow A from the state of FIG. FIG. 7 shows the state in which the operation is performed. As shown in FIG. 7, since the upper wire 7a passes through the centers of the wire passage holes 13a and 13b, the upper wire 7a is not in contact with the fixed substrate 11, and is indicated by the arrow i of the solder 10 fixed to the terminal plate 14b. The portion is deformed into a cantilever shape with the fixed end. On the other hand, the lower wire 7
Since b is in contact with the fixed substrate 11 at the portion indicated by the arrow j in FIG. 7, it bends at the portion indicated by j. Therefore, the upper wire 7a and the lower wire 7b are differently deformed. Therefore, as shown in FIG. 7, the connection substrate 9 is largely inclined toward the fixing portion. This indicates that the movable section is inclined, and therefore, the inclination of the objective lens 1 is increased. When the connection board 9 moves upward as shown in FIG. 7, the wire 7b comes into contact with the portion j of the fixed board 11, but when the connection board 9 moves down, the connection board 9
In addition, since the contact holes do not contact the wire passage holes 13c and 13d of the fixed substrate 11, the length between the contact points of the wires 7b differs between when the connection substrate 9 moves upward and when it moves downward. For this reason, the natural frequency of the wire 7b changes, and the servo characteristics are shifted.

In order to avoid the above-mentioned contact between the wires 7b and the fixed substrate 11, a method of enlarging the wire passage holes 13a, 13b, 13c and 13d of the fixed substrate 11 and the connection substrate 9 is considered. FIG. 8 is a sectional side view showing the positional relationship between the wires and the substrate. In FIG. 8, the wire 7
With respect to the diameters of a and 7b, the fixed substrate 11 and the wire passage holes 13a, 13b, 13b, 13c and 13d of the connection substrate 9
Also, the wire passage holes of the terminal plates 14a, 14b, 14c and 14d were made sufficiently large. The solid line is the right side in FIG.
FIG. 5 shows two wires 7a and 7b on the near side,
The dotted lines indicate the two wires 7c and 7d on the left side in FIG. 4 and on the back side in FIG. From this state, even if the movable part is moved in the direction of arrow A, the wires 7a, 7b, 7c, 7
d, the edges of the wire passage holes 13b and 13d of the fixed substrate 11 (the wire passage holes provided in the fixed substrate 11 for passing the wires 7c and 7d are not shown in the drawing), and the wire passage holes of the connection substrate 9 13a, 13c (wire 7d,
(The wire passing holes provided in the connection board 9 for passing 7d are not shown in the drawing.) There is a sufficient gap between the wire 7a to 7d, the fixed board 11, and the connection board 9 But never touch. However, even when the relative positions of the wires 7a to 7d and the fixed board 11 and the connection board 9 are displaced during assembly, the wires 7a to 7d are formed by the edges of the wire passage holes 13a to 13d of the fixed board 11 and the connection board 9. Position is not regulated. Also, the terminal boards 14a to 14
Since the wire passing holes d have the same diameter as the wire passing holes 13a to 13d of the fixed board 11 and the connection board 9, the positions of the wires 7a to 7d are not restricted. For this reason, the gap between the upper and lower wires 7a and 7b and between the wires 7c and 7d becomes large. That is, two wires 7a and 7b on the near side shown by solid lines and two wires 7a on the back side shown by dotted lines.
The intervals of c and 7d are different. Also in this case, when the movable part is moved in the direction of arrow A, the movable part is greatly inclined in various directions, the inclination of the objective lens 1 is increased, and servo cannot be performed properly.

As shown in FIG. 8, the wire passage holes 1 of the fixed substrate 11 and the connection substrate 9 correspond to the diameters of the wires 7a to 7d.
3a to 13d, and terminal plates 14a to 14
When the wire passage hole of 14d is made sufficiently large, it is necessary to make the distances between the wires 7a and 7b and 7c and 7d equal to each other in order to prevent the above-mentioned disadvantage. For this purpose, the wires 7a to 7d, the movable portion and the fixed portion are accurately set at predetermined relative positions during assembly, and the wires 7a to 7d are fixed to the fixed substrate 11 and the wire passage holes 13a to 13d of the connection substrate 9. It is necessary to pass through the center of. For this purpose, extremely high assembling accuracy is required, and the assembling efficiency is greatly deteriorated. Therefore, even if the relative positions of the wires 7a to 7d, the movable portion and the fixed portion are displaced during assembly, the displacement of the mounting positions of the wires 7a to 7d is reduced, and the inclination of the objective lens 1 accompanying the movement of the movable portion is reduced. In order to reduce the size, it is necessary to restrict the positions of the wires 7a to 7d by the edges of the wire passage holes 13a to 13d of the fixed board 11 and the connection board 9 during assembly. That is, the diameter of the wire passage holes 13a to 13d of the fixed board 11 and the connection board 9 is as small as possible within a range that does not deteriorate the assemblability when the wires 7a to 7d are passed through the wire passage holes 13a to 13d. Must be close to the diameter. Therefore, the method of enlarging the wire passage holes 13a to 13d of the fixed substrate 11 and the connection substrate 9 shown in FIG. 8 cannot be adopted.

FIG. 1 is a sectional side view of a wire and a substrate showing a first embodiment of the objective lens driving device according to the present invention.
As shown in FIG. 1, the wire passage holes 23b and 23d provided in the fixed substrate 11 fixed to the fixed portion are provided with the wires 7a and 7d.
It has a conical shape (a so-called tapered shape) whose diameter gradually increases toward the movable portion in the axial direction of b. That is, the wire passing holes 23b and 23d are configured such that the diameter of the hole facing the movable portion is increased. Fixed substrate 1
In the first wire passage holes 23b and 23d, the terminal plate 24
b, 24d are in contact with the terminal plates 24b, 24d.
And the diameter of the wire 7a, 7b
Is the closest to the diameter of the wires 7a, 7b within a range that does not degrade the assemblability when passing through the wire passage holes 23b, 23d. The wire passage holes 23a and 23c provided in the connection board 9 of the movable section have a conical shape whose diameter gradually increases toward the fixed section, that is, the fixed board 11 in the axial direction of the wires 7a and 7b. . In the wire passage holes 23a, 23c of the connection board 9, the terminal plates 24a,
The diameter of the portion in contact with 24c matches the diameter of the wire passage holes of the terminal plates 24a and 24c, and the wires 7a and 7b are connected to the wire passage holes 23a and 23c of the connection board 9 as in the case of the fixed board 11. It is a value closest to the diameter of the wires 7a and 7b as long as the assemblability at the time of passing is not deteriorated.

As in the case of FIG. 6, the upper wire 7a
Are fixed through substantially the centers of the wire passage holes 23b of the fixed substrate 11 on the fixed portion side and the wire passage holes of the terminal plate 24b. In addition, the wire passes through the center of the wire passage hole 23a of the connection board 9 on the movable portion side and the wire passage hole of the terminal plate 24a. On the other hand, the lower wire 7b
Are fixed in a state shifted from the centers of the wire passage holes 23c and 23d. However, since the position of the wire 7b is regulated by the minimum diameter portions of the wire passage holes 23c and 23d of the connection board 9, the fixed board 11, and the edges of the wire passage holes of the terminal plates 24c and 24d, the amount of displacement is small. 8 are smaller than those in FIG. Note that the terminal plates 24a to 24d in FIG. 1 are configured to fit into recesses provided in the connection substrate 9 and the fixed substrate 11.

FIG. 2 is a sectional side view when the movable part is moved in the direction of arrow A from the state of FIG. As shown in FIG. 2, the upper wire 7a is not in contact with the fixed substrate 11, and is deformed into a cantilever shape with the portion indicated by the arrow i of the solder 10 fixed to the terminal plate 24b as a fixed end. Also, wire 7
a is not in contact with the connection substrate 9 either. On the other hand, the lower wire 7b does not contact the fixed board 11 or the connection board 9 either. This is because the wire passage hole 23d of the fixed substrate 11 has a conical shape in the axial direction of the wire 7b toward the movable portion, and the wire passage hole 24c of the connection substrate 9 has a conical shape in the axial direction of the wire 7b toward the fixed portion. Because it is. Therefore, the lower wire 7b is also deformed into a cantilever shape with the portion indicated by the arrow j of the solder 10 as a fixed end. That is, the upper and lower wires 7a and 7b are deformed into the same shape. Further, as described above, in FIG. 2, since the positions of the wires 7a and 7b are regulated by the edges of the holes of the terminal plates 24a to 24d, the gap between the wires does not occur as shown in FIG. The objective lens 1 does not tilt.

According to this embodiment, the interval between the wires 7a and 7b can be set within a predetermined error range without requiring extremely high assembling accuracy, and the movable portion can be set in a direction parallel to the optical axis of the objective lens 1, and The objective lens 1 does not tilt with respect to the disk surface even when the objective lens 1 is moved in the direction perpendicular to the disk.

FIG. 9 is a sectional side view of a substrate and wires showing a second embodiment of the objective lens driving device according to the present invention.
As shown in FIG. 9, the diameters of the wire passage holes 33b and 33d provided in the fixed substrate 11 of the fixed portion are the same as those of the terminal plates 24b and 24d.
Is larger than the diameter of the wire passage hole. The diameter of the wire passage holes of the terminal plates 24b and 24d is the largest in the range that does not deteriorate the assemblability when the wires 7a and 7b are passed through the wire passage holes, similarly to the terminal plates 24a to 24d shown in FIG. The value is closer. The wire passage holes 33b and 33d of the fixed substrate 11 are sufficiently larger than the diameters of the wires 7a and 7b. Also, the diameter of the wire passage holes 33a, 33c provided in the connection board 9 of the movable part is the same as that of the terminal plate 24a,
24c is larger than the diameter of the wire passage hole. The diameter of the wire passage holes of the terminal plates 24a, 24c is a value closest to the wire diameter as long as the assemblability when passing the wires 7a, 7b through the wire passage holes is not deteriorated. The wire passage holes 33b and 33d of the fixed substrate 11 are sufficiently larger than the diameters of the wires 7a and 7b. Further, the wire passage holes provided in the connection board 9 and the fixed board 11 for passing the wires 7c and 7d and the wire passage holes of the terminal plate are configured in the same manner as described above. From this state, even if the movable part is moved in the direction of arrow A, between the wires 7a, 7b and the edges of the wire passage holes 33b, 33d of the fixed substrate 11, or between the wire passage holes 33a, 33c of the connection substrate 9. Since there are sufficient gaps, the wires 7a and 7b do not come into contact with the substrates 9 and 11. The same can be said for the wires 7c and 7d. Now, the wires 7a and 7b are fixed through substantially the centers of the wire passage holes of the fixed board 11, the connection board 9, and the terminal board 14, and the wires 7c are fixed to the wire passage holes of the fixed board 11 and the connection board 9. 9, the wire 7d is fixed above the center of the wire passage hole of the fixed board 11 and the connection board 9 in the state shifted downward in FIG. The position is regulated by the portion of the fixed substrate 11 and the connection substrate 9 having the smallest diameter of the wire passage hole, and the edge of the wire passage hole of the terminal plate (not shown in the figure). Two wires 7a and 7b,
The distance between the two wires 7c and 7d on the far side shown by dotted lines may be said to be substantially equal, and is within a predetermined error range. .

According to the present embodiment, as in the first embodiment, the wires 7a and 7b can be used without requiring extremely high assembly accuracy.
The distance between 7c and 7d can be set within a predetermined error range, and the objective lens 1 is inclined with respect to the disk surface even if the movable part is moved in a direction parallel to the optical axis of the objective lens 1 and in a direction perpendicular to the optical axis. There is no.

FIG. 10 is a sectional side view of a substrate and wires showing a third embodiment of the objective lens driving device according to the present invention. As shown in FIG. 10, wire passing holes 23b and 23d provided in the fixed substrate 11 fixed to the fixed portion and the terminal plate 3
The diameter of the wire passage hole of 4b, 34d is the wire 7a, 7b
Has a conical shape whose diameter gradually increases toward the movable portion in the axial direction. Here, the wire passage holes 23b and 23d of the fixed substrate 11 and the wire passage holes of the terminal plates 34b and 34d are continuously formed in a conical shape. This terminal plate 3
The minimum diameter of the wire passage hole of 4b, 34d is the wire 7a,
7b is the value closest to the wire diameter within a range that does not degrade the assemblability when passing 7b through the wire passage holes of the terminal plates 34b and 34d. Further, the wire passage holes 23a and 23c provided in the connection board 9 of the movable portion and the terminal plates 34a and 34
The diameter of the wire passage hole c has a conical shape whose diameter gradually increases toward the fixed portion in the axial direction of the wires 7a and 7b. Here, the wire passage hole 23 of the connection board 9
a, 23c and the wire passage holes of the terminal plates 34a, 34c
It has a conical shape continuously. The terminal plates 34a, 3
The minimum diameter of the wire passage hole 4c is within a range that does not deteriorate the assemblability when the wires 7a and 7b are passed through the wire passage hole.
The value is closest to the wire diameter. In this embodiment, the shape of the wire passage holes 23a to 23d provided in the fixed board 11 and the connection board 9 is the same as that shown in FIG. Is different from the embodiment shown in FIG. 1 in that the minimum diameter of the conical shape is a value closest to the wire diameter.

Even if the movable part is moved in the direction of arrow A from the state shown in FIG.
1. There is no contact with the connection board 9. Further, since the positions of the wires 7a and 7b are regulated by the edge of the portion having the smallest diameter in the wire passage holes of the terminal plates 34a to 34d, the intervals between the two wires 7a and 7b can be made substantially equal. .

According to this embodiment, as in the first and second embodiments, extremely high assembly accuracy is not required and the wires 7a, 7
The distance b can be set within a predetermined error range, and the objective lens 1 does not tilt with respect to the disk surface even when the movable part is moved in a direction parallel to and perpendicular to the optical axis of the objective lens 1. . Further, according to this embodiment, the substrates 9, 11 and the terminal plates 34a to 34d can be simultaneously processed by a conical drill or the like, so that the processability is improved and the cost can be reduced.

In the above description of the first to third embodiments of the present invention, the configuration of the wire and the substrate on the right side of FIG. 4 will be mainly described with reference to FIGS. 1, 2, 9 and 10. However, it is clear that the wire and the substrate on the left side of FIG. 4 have the same configuration. Further, in the embodiment of the present invention, a wire has been described as an example of the elastic support member. However, the cross section of the wire does not necessarily have to be circular and may be polygonal. Further, the elastic support member may be any one that can move up, down, left and right with elasticity. The first and third embodiments of the holes provided in the fixed substrate and the connection substrate have been described as having a conical shape with reference to FIGS. 1 and 10; however, the holes need not necessarily be conical, and may be formed on one side of the substrate. It is clear that the object and effect of the present invention can be achieved if the size of the hole is configured to be larger than the size of the hole on the other side.
In the embodiment of the present invention, the fixed substrate 11 is
The fixed substrate 11 is attached to the yoke 4
It may be attached to. That is, a notch may be provided in the yoke 4 and a rib provided on the substrate may be inserted into the notch and fixed.

[0028]

As described above, in the objective lens driving device according to the present invention, the movable part side and the fixed part side substrate and the terminal board are configured as proposed in the present invention. In the direction parallel to the optical axis of the objective lens,
And even if moved in the direction perpendicular to the optical axis of the objective lens,
The objective lens is hardly inclined with respect to the optical disk.

[Brief description of the drawings]

FIG. 1 is a sectional side view showing a first embodiment of an objective lens driving device according to the present invention.

FIG. 2 is a sectional side view of the first embodiment of the objective lens driving device shown in FIG. 1 when the connection substrate is moved in the direction of arrow A;

FIG. 3 is a perspective view of an objective lens driving device.

FIG. 4 is a plan view of the objective lens driving device.

FIG. 5 is a side view of the objective lens driving device.

FIG. 6 is a sectional side view showing a conventional objective lens driving device.

FIG. 7 is a cross-sectional side view when the connection board is moved in the direction of arrow A in FIG.

FIG. 8 is a sectional side view showing the objective lens driving device.

FIG. 9 is a cross-sectional side view showing a second embodiment of the objective lens driving device according to the present invention.

FIG. 10 is a sectional side view showing a third embodiment of the objective lens driving device according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Objective lens, 2 ... Bobbin, 3 ... Focusing coil, 3a ... Longitudinal component of a focus coil, 4 ... Yoke, 5 ... Magnet, 6 ... Tracking coil, 7a-
7d: wire, 8: holder, 9: connection board, 10: solder, 11: fixing section board, 23a to 23d, 33a to 33
d: wire passage holes, 24a to 24b, 34a to 34d ...
Terminal board

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Nobuyuki Maeda 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Pref. Multimedia System Development Division, Hitachi, Ltd. 292, Hitachi, Ltd. Multimedia System Development Division, Hitachi, Ltd. (72) Inventor Michio Miura 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Pref. Hitachi, Ltd.Video Information Media Division (72) Inventor Akio Yabe Kanagawa 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Japan Inside Hitachi Image Information System Co., Ltd.

Claims (14)

[Claims] 1. A movable part comprising an objective lens and a bobbin for holding the objective lens, and a force mounted on the movable part and driving the movable part in a direction parallel to an optical axis of the objective lens. A focus coil, a tracking coil attached to the movable part and generating a force for driving the movable part in a direction orthogonal to the optical axis of the objective lens, a focusing coil, and a magnetic circuit for generating a magnetic flux acting on the tracking coil And a first substrate attached to the movable portion, a second substrate held by a fixed portion movably supporting the movable portion with respect to the fixed portion, The other end is supported by the second substrate, and the movable portion is parallel to the optical axis of the objective lens with respect to the second substrate. And an elastic support member movable in a direction orthogonal to the optical axis of the objective lens, wherein the second substrate is provided with a hole through which the elastic support member passes, and the second substrate is provided with the hole. An objective lens driving device, wherein the size of the hole on the side facing the movable portion of the hole is larger than the size of the hole on the other side of the second substrate. 2. A movable section comprising an objective lens, a driving means for the objective lens, and a bobbin for holding the objective lens, a first substrate attached to the movable section, and a first substrate disposed opposite to the first substrate. And a second substrate forming a fixed portion with respect to the movable portion, and the second substrate is inserted and fixed in holes provided in the first substrate and the second substrate, and the second substrate is fixed to the second substrate. An elastic support member that movably supports one substrate,
An objective lens driving device, characterized in that a diameter of the hole provided on the second substrate on a side facing the movable portion is larger than a diameter of the hole on the opposite side. 3. A movable part comprising an objective lens, a driving means for the objective lens, and a bobbin for holding the objective lens, a first substrate attached to the movable part, and a first substrate disposed opposite to the first substrate. Forming a fixed portion with respect to the movable portion;
A terminal board attached to a surface of the first substrate and the second substrate opposite to a facing surface of the first substrate, the first substrate, the second substrate, and the first and second substrates. An elastic support member inserted into and fixed to a hole provided in the terminal plate attached to the substrate and movably supporting the first substrate with respect to the second substrate; provided on the second substrate; An objective lens driving device, wherein the size of the hole on the side facing the movable portion of the hole is larger than the size of the hole of the terminal plate. 4. The objective lens driving device according to claim 1, wherein four elastic support members are provided, and the movable portion is provided in an optical axis direction of the objective lens and in a direction orthogonal to the optical axis. An objective lens driving device, which is movably supported. 5. The objective lens driving device according to claim 1, wherein a hole for passing the elastic support member is provided in the first substrate, and the first substrate faces the second substrate. An objective lens driving device, wherein the size of the hole on the side is made larger than the size of the hole on the side opposite to the first substrate. 6. The objective lens driving device according to claim 1, wherein said hole provided in said second substrate has a conical shape. 7. The objective lens driving device according to claim 1, wherein a hole for passing the elastic support member is provided in the first substrate, and the first substrate is opposed to the second substrate. An objective lens driving device, characterized in that the shape of the hole is conical so that the size of the hole on the side is larger than the size of the hole on the side opposite to the first substrate. 8. The objective lens driving device according to claim 3, wherein said holes provided in said second substrate and said holes provided in said terminal plate have a continuous conical shape. Lens driving device. 9. The objective lens driving device according to claim 3, wherein the size of the hole provided on the first substrate on the side facing the second substrate is larger than the size of the hole on the terminal plate. An objective lens driving device characterized by being enlarged. 10. The objective lens driving device according to claim 3, wherein the size of the hole provided in the first substrate facing the second substrate is larger than the size of the hole of the terminal plate. An objective lens driving device, wherein the shape of the hole provided in the first substrate and the shape of the hole provided in the terminal plate are a continuous conical shape. 11. A movable part comprising an objective lens and a bobbin for holding the objective lens, and a force attached to the movable part and driving the movable part in a direction parallel to an optical axis of the objective lens. A focus coil, a tracking coil attached to the movable part and generating a force for driving the movable part in a direction orthogonal to the optical axis of the objective lens, a focusing coil, and a magnetic circuit for generating a magnetic flux acting on the tracking coil A driving unit comprising: a fixed portion supporting the movable portion; a substrate attached to the fixed portion; and a movable portion having one end attached to the movable portion and the other end attached to the substrate. An elastic support member movable in a direction parallel to the optical axis of the objective lens and in a direction orthogonal to the optical axis of the objective lens. In addition, the substrate is provided with a hole through which the elastic support member penetrates, and the hole of the substrate has a conical portion whose diameter increases in a direction in which the elastic support member extends. Objective lens driving device. 12. The objective lens driving device according to claim 11, wherein another substrate for fixing one end of the elastic support member is attached to the bobbin, and the elastic support member penetrates the other substrate. A hole is provided,
The objective lens driving device, wherein the hole of the other substrate has a conical portion whose diameter increases in a direction in which the elastic support member extends. 13. A movable part comprising an objective lens and a bobbin holding the objective lens, and a force which is attached to the movable part and drives the movable part in a direction parallel to an optical axis of the objective lens. A focus coil, a tracking coil attached to the movable part and generating a force for driving the movable part in a direction orthogonal to the optical axis of the objective lens, a focusing coil, and a magnetic circuit for generating a magnetic flux acting on the tracking coil And a fixed part supporting the movable part, a substrate attached to the fixed part, and one end attached to the movable part, and the other end attached to the substrate. An elastic support member movable in a direction parallel to the optical axis of the objective lens and in a direction perpendicular to the optical axis of the objective lens. The substrate attached to the fixing portion holds a conductive terminal plate on a surface opposite to a direction in which the elastic support member extends, and the terminal plate has a hole through which the elastic support member passes. The hole of the terminal plate and the hole of the substrate are arranged so as to be substantially concentric, and the diameter of the hole of the substrate is larger than the diameter of the hole of the terminal plate. Objective lens drive. 14. The objective lens driving device according to claim 13, wherein said hole of said substrate and said hole of said terminal plate are formed in a continuous conical shape.