JP2003085796A - Objective lens driving device and optical pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a movable part from being stuck with an adhesive adhering to a stopper. SOLUTION: The objective lens driving device is equipped with a yoke made of a magnetic material having a U-shaped cross section, an auxiliary yoke plate mounted on the upper end face of the yoke and provided with a stopper extending outward from both sides of the yoke, and a permanent magnet fixed on the yoke. A part of the movable part which holds an objective lens, a focusing coil and a tracking coil, is brought into contact with the stopper of the auxiliary yoke plate, thereby restraining the upward movement of the movable part. The auxiliary yoke plate is mounted on the upper end face of the yoke by means of the adhesive or by the adhesive and caulking. On the inner side from the stopper of the auxiliary yoke plate, there is provided an adhesive leak preventing means preventing the adhesive from leaking out to the stopper portion where the part of the movable part can come into contact.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective lens driving device and an optical pickup device, and more particularly to driving an objective lens in which an auxiliary yoke plate (yoke upper wall) of a yoke assembly has stopper portions on both outer sides. The present invention relates to a device and an optical pickup device.

[0002]

2. Description of the Related Art For example, in Japanese Unexamined Patent Publication No. 10-124901, "In order to record information on an optical disc or read information recorded on the optical disc, an objective lens for irradiating the optical disc with a light beam, A yoke portion having a pair of leg portions having a U-shaped cross section for driving in a direction perpendicular to the recording surface of the optical disc and a radial direction of the optical disc, and disposed on an inner surface of at least one leg portion of the yoke portion. In an optical pickup device having a magnetic circuit composed of a magnet that generates magnetic force lines between both legs, in advance, among a plurality of small magnetic members of different thickness, shape, or magnetic characteristics, An optical pick-up characterized by using at least one magnetic member to adjust a magnetic flux density distribution generated in the yoke portion by the magnet. Method of adjusting the radial dynamic skew device ", or to record information in" optical disk,
Alternatively, an optical system having a magnetic circuit for driving an objective lens for irradiating the optical disc with a light beam to read information recorded on the optical disc in a direction perpendicular to the recording surface of the optical disc and in a radial direction of the optical disc. In the pickup device, the magnetic circuit includes a yoke portion having a pair of leg portions having a U-shaped cross section and a magnet disposed on an inner surface of at least one leg portion of the yoke portion and generating a magnetic force line between the leg portions. An optical pickup device characterized in that a small magnetic member for adjusting the magnetic flux density distribution of the yoke portion is bridged to both legs of the yoke portion is disclosed. ing.

In the above publication, the "magnetic member" is caulked and fixed to the upper surface of the yoke portion, but no adhesive is used. Further, the "magnetic member" does not have a stopper portion that restricts the upward movement of the movable portion that holds the objective lens.

Further, in Japanese Patent No. 2892557,
"A lens holding portion that holds an objective lens, a coil holding portion that is provided continuously to the lens holding portion, is supported so as to be able to float in the focus direction together with the lens holding portion, and holds a coil, and cooperates with the coil. A magnetic circuit for driving the objective lens in the focus direction or the tracking direction,
A protective plate fixedly arranged so as to cover the coil disposed in the magnetic gap of the magnetic circuit, and a position where the lens holding portion contacts before the coil floats in the focus direction and contacts the protective plate. And a stopper provided as a part of the protection plate. In this device, a protective plate attached to a yoke portion that is a magnetic circuit is provided with a stopper that restricts upward movement of a lens portion (which is connected to a coil holding portion that holds a coil) that holds an objective lens. Prepared as a part. However, this publication also does not disclose how the protective plate is attached to the upper surface of the yoke portion.

FIG. 25 shows a main part of an objective lens driving device developed by the present applicant, in which a yoke assembly Y is fixed to a fixed base S and a yoke low wall,
A pair of yoke side wall portions integrally extending upward from this,
The yoke upper wall A as an auxiliary yoke plate is attached to the upper surface of the yoke side wall with an adhesive d. The movable portion K holding the objective lens and the focus coil F (not shown) is integrally formed with a protrusion P, which is a stopper portion A formed at both outer ends of the yoke upper wall A.
When the movable part K moves upwards more than an allowable amount, it comes into contact with a and Aa, so that an unexpected failure does not occur. As shown in FIG. 25A, if the leaking movable portion K is not allowed to move upward beyond an allowable level until the adhesive d is unnecessary, as shown in FIG.
As shown in 5B, one or both stoppers A
There is a possibility that the protrusion P may be stuck to the a and may not move, resulting in damage to a part of the device. In addition, a serious defect occurs in the operating characteristics of the optical pickup device using this.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a stopper portion is stuck to a movable portion by an adhesive to damage a part of the device, or a serious defect in pickup operation characteristics occurs. It is an object of the present invention to provide a fearless objective lens driving device and an optical pickup device.

[0007]

SUMMARY OF THE INVENTION The above-mentioned problems are solved by a yoke portion made of a magnetic material having a U-shaped cross section, and a stopper portion attached to the upper end surface of the yoke portion and extending outward from both sides of the yoke portion. Of the objective lens, a part of the movable part that holds the focus coil and the tracking coil, and the stopper part of the auxiliary yoke plate. In the objective lens driving device configured to limit the upward movement of the movable part by abutting, the auxiliary yoke plate is attached to the upper end surface of the yoke part by an adhesive or an adhesive and caulking, and the auxiliary yoke plate Adhesive leakage preventive means is provided inward of the stopper portion, and the adhesive is not applied to a portion of the stopper portion that can come into contact with the movable portion. Is solved by a drive device, the objective lens is characterized in that so as not to leak out.

Alternatively, in order to record information on the optical disc and / or reproduce the information recorded on the optical disc, an objective lens for converging and irradiating a light beam on the optical disc, and a movable portion for holding the objective lens. , A fixed part that is connected to this movable part with a pair of left and right / upper and lower suspension wires, a yoke part made of a magnetic material with a U-shaped cross section that is fixed to this fixed part, and attached to the upper end surface of this yoke part. And an auxiliary yoke plate having stopper portions extending outward from both sides of the yoke portion, a permanent magnet fixed to the yoke portion, and a magnetic flux from the permanent magnet passing through the yoke portion. The movable unit includes a focus coil and a tracking coil held by the movable unit for driving the movable unit in the focus direction and the tracking direction, respectively. In an optical pickup device in which a part of the auxiliary yoke plate abuts on the stopper portion so as to limit the upward movement of the movable portion, the auxiliary yoke plate is attached to the upper end surface of the yoke portion with an adhesive or Attached by adhesive and caulking, an adhesive leakage prevention means is provided inward of the stopper portion of the auxiliary yoke plate, and by this means, a portion of the stopper portion that can come into contact with the part of the movable portion is provided. Is solved by an optical pickup device characterized in that the adhesive is prevented from leaking from the inside.

With the above construction, the stopper portion of the yoke upper wall as the auxiliary yoke plate and the adhesive agent do not cause a situation of sticking and always guarantee good operating characteristics.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below with reference to FIGS. With reference to FIGS. 1 to 3, in an objective lens driving device 1, a movable part 3 holding an objective lens 2 is connected to a fixed part 4 by a pair of upper, lower, left and right suspension wires 5. As a result, the movable portion 3 can move vertically and horizontally. Fixed part 4
Are fixed to the fixed base 6. The movable portion 3 holding the objective lens 2 further holds a focus coil 7 and a pair of tracking coils 8a and 8b. Figure 3-
As shown in FIG. 6, the yoke assembly 9 is integrated with the fixed base 6. It is composed of a yoke bottom wall 9a, a pair of yoke side walls 9b and 9c extending upward from the yoke bottom wall 9a, and a yoke upper wall 11 as an auxiliary yoke plate which is attached to the upper surfaces thereof with an adhesive d. Permanent magnets 10a and 10b are attached to the inner surfaces of the yoke side walls 9b and 9c which face each other.

Next, details of the yoke upper wall 11 as the auxiliary yoke plate according to the present invention will be described. York upper wall 1
1 is a rectangular flat plate shape as a whole as shown in FIGS. 1 and 6 to 8. A pair of semi-circular cutouts 16 are formed in the central portions of both side edge portions, and bent portions 12a and 12b bent in a stepwise manner are formed therebetween. Semicircular notches 13a and 13b are formed at this end. A yoke forming portion 14 is formed between them, and portions extending outward from the yoke forming portion 14 are stopper portions 15a and 15b. Grooves 17a and 17b according to the present invention are formed at boundaries between the yoke forming portion 14 and the stopper portions 15a and 15b. The groove is formed by coining or pressing, and almost no convex portion is formed on the opposite surface, and the groove remains almost flat. This reduces the height of the entire device. That is, a thin design can be achieved.
Further, by this coining or pressing, work hardening of the material of the yoke upper wall 11 can be obtained, and advantageous strength can be obtained against deformation of the present component due to vertical impact.

Protrusions 18a and 18b are formed at portions of the movable portion 3 that face the stoppers 15a and 15b.
As shown in FIGS. 3, 4 and 5, the upper surfaces thereof are higher than the upper surfaces of both sides and both outer side portions of the yoke side walls 9b and 9c. As shown in FIG. 1, the objective lens 2 held by the movable portion 3 is supported by a pair of upper and lower suspension wires 5 in the radial direction x (tracking direction) of the disk.
And its optical axis direction y (focus direction). Therefore, in FIG. 2, the protrusions 18a, 18
The distance between b and the grooves 17a and 17b is larger than the maximum movement distance of the movable portion 3 in the x direction. The objective lens 2 is attached to the movable portion 3 with an adhesive d at three points as clearly shown in FIG. At such a position, the entire adhesive d is sufficiently irradiated with ultraviolet rays, so that it does not flow out to an unnecessary area.

The first embodiment of the present invention is constructed as described above, and its operation will be described below. The objective lens driving device 1 is arranged in a disk recording and / or reproducing device in a known manner (see FIG. 24 described later). The objective lens 2 is arranged close to a disk that is driven to rotate by a spindle motor. Return light coming from the disc through the objective lens 2 is processed by a known mechanism to reproduce information on the disc. At this time, a control current is passed through the focus coil 7 and the tracking coils 8a and 8b so that the information on the disc can be always read accurately. When a control current is passed through the coils 7, 8a, 8b, the movable portion 3 moves in the x direction and / or the y direction in FIG. 1 due to the interaction with the magnetic flux flowing in the yoke assembly 9. At this time, according to the optical pickup device 1 of the present invention, the control operation is always guaranteed accurately.

Next, the assembling work of the yoke assembly 9 will be described. The bent portions 12a and 12b of the yoke upper wall 11 are fitted into the notches 9ba and 9ca (see FIG. 1) formed at the upper ends of the yoke side walls 9b and 9c and press-contacted, and then the adhesive d is placed on top of this. (Syringe)
It is applied with. The adhesive d is cured by being irradiated with ultraviolet rays. Since the bent portions 12a and 12b are positioned by the notches 9ba and 9ca, the yoke upper wall 11 is accurately attached to the yoke assembly 9. Even if the adhesive d is excessively applied and protrudes from the notch 16 to the lower surface of the yoke upper wall 11, the adhesive d is taken in by the grooves 17a and 17b and does not leak further outward. As shown in FIG. 8, the adhesive d that has flowed in through the gap between the lower surfaces of the bent portions 12a and 12b and the recesses 9ba and 9ca formed in the upper ends of the yoke side walls 9b and 9c is the outer stopper portion 15a, 15b
It flows toward, but is stuck in the grooves 17a and 17b and cannot proceed any further. Therefore, it does not flow into the stopper portions 15a and 15b. That is, the stopper portions 15a and 15b
Since the adhesive does not leak out to, the protrusions 18a and 18b of the movable portion 3 directly contact with each other. Therefore, even if the movable portion 3 is moved upward largely for some reason, the movable portion 3 is prevented from further moving by its original function.

Next, an objective lens driving section of an optical pickup device according to a second embodiment of the present invention will be described with reference to FIGS. 9 to 13. The yoke assembly includes a yoke portion 21 having a U-shaped cross section and a yoke upper wall 23, which are integrated by an adhesive d. The yoke portion 21 includes a yoke lower wall 21a and both side wall portions 21b and 21c integrally extending upward from the lower wall 21a. Protrusions 22a and 22b are formed in the center of the upper ends of these. A pair of hanging parts 23a, 23b are formed on both side edges of the yoke upper wall 23 corresponding to the projecting parts 22a, 22b, and the projecting parts 22a, 22b of the yoke part 21 are fitted in the notches c between them. Are combined.

A rectangular space is formed by the inner side surfaces of the hanging parts 23a and 23b and the upper surfaces of the protrusions 22a and 22b. Here, as shown in FIG. 11, the adhesive d is filled with a shrinkage. The adhesive cures when exposed to ultraviolet light. However, before the adhesive is cured, FIG.
As shown in FIG. 3, the adhesive d may leak to the bottom surface of the yoke upper wall 23. This is the outer stopper 24a, 2
4b, but is blocked by the grooves 25a and 25b. As shown in FIGS. 12 and 13, the adhesive d flows inward through the gap between the upper surfaces of the protrusions 22 a and 22 b and the both side edges of the central portion of the yoke upper wall 23. At this time, since no ultraviolet ray is emitted, the inflow proceeds gradually and flows into the shallow recess e. The adhesive d that has flowed in here is stopped by the inner wall of the recess e and does not proceed further outward, but the adhesive d that flows on the outer surface f of the recess e flows outwardly. It is guided into 25a and 25b. Therefore, the adhesive d does not reach the stopper portions 24a and 24b. According to the present invention, the adhesive d is guided into the grooves 25a and 25b and does not flow out from the grooves 25a and 25b to the stopper portions 24a and 24b. In the embodiment of the present invention, the adhesive d is also introduced into the recess e, and the groove 25 on the outer side of the adhesive d is introduced.
The burden on a and 25b is reduced.

FIG. 14 is a perspective view of the yoke upper wall 30 of the yoke assembly in the objective lens driving device according to the third embodiment of the present invention, but other configurations are similar to those of the first embodiment of the present invention. Is. In this embodiment, protrusions 32a and 32b are formed inside the stopper portions 34a and 34b at both ends. The adhesive that has flowed from the central portion of the yoke upper wall 30 is dammed up by these and does not move outward any further. Therefore, the same effect as that of the above-described embodiment of the present invention can be obtained.

16 to 17 are perspective views of the yoke upper wall 40 of the yoke assembly in the objective lens driving device according to the fourth embodiment of the present invention, the other parts being the same as those of the first embodiment of the present invention. It is the same. In the embodiment of the present invention, the stopper portions 42a and 42b are much higher than the central portion in the inverted posture as shown in the drawing. That is, steps 44a and 44b are provided between the stopper portions 42a and 42b and the central portion (yoke forming portion). Due to these, the adhesive d flowing from the central portion is dammed here, and there is no further outward flow. Therefore, the same effect as each of the above-described embodiments of the present invention is obtained. Although the steps 44a and 44b are formed so as to be displaced downward, they may be arranged to be displaced upward. The same effect can be obtained with this.

18 to 19 are perspective views of the yoke upper wall 50 of the yoke assembly in the objective lens driving device according to the fifth embodiment of the present invention, but the other parts are the same as those of the first embodiment of the present invention. It is the same. In the embodiment of the present invention, the stopper portions 52a and 52b are located inward, but from both side edges of the central portion inward, that is, the bent portions 12a and 1b.
Trapezoidal grooves 54a and 54b are formed inside 2b. As described in the first embodiment of the present invention, the bent portion 1
When the adhesive d is applied on the surfaces 2a and 12b, the adhesive d flowing into the central portion from here is introduced into these arcuate grooves 54a and 54b, and the further progress is stopped. To be Therefore, the adhesive d is not applied to the stopper portions 52a and 52b. Therefore, also in the embodiment of the present invention, the same effect as that of the above-described embodiment can be obtained.

20 to 23 are exploded perspective views of the yoke assembly of the objective lens driving device according to the sixth embodiment of the present invention. The yoke portion 62 includes a yoke lower wall 64a and a yoke side wall integrally extending upward from the yoke lower wall 64a. The yoke side walls 64b and 64c are integrally formed with wedge-shaped protrusions 65a and 65b at the upper end center portions thereof. A pair of rectangular parallelepiped protrusions 70a and 70b are formed on both side edges of the yoke upper wall 60, and a groove 72 is formed on the outside of these protrusions 70a and 70b.
a and 72b are formed, and further stopper portions 68a and 68b are formed on the outside thereof.

When attaching the yoke upper wall 60 to the yoke forming portion, first, the adhesive d is applied to both sides of the protrusions 65a and 65b. Then, the yoke upper wall 60 has its protrusions 70 a and 70 b attached to the protrusion 65 of the yoke forming portion 62.
The protrusions 70a and 70b are arranged so as to engage with both side edges of a and 65b, and the protrusions 70a and 70b are pressed from the outside to the inside by a tool. The protruding portions 70a and 70b of the yoke upper wall 60 are deformed inward and fixed to the yoke portion 62 by caulking. The adhesive d is irradiated with ultraviolet rays. As a result, as shown in FIGS. 19 and 20, the adhesive d which has flowed into the back side of the yoke upper wall 60 before being cured has fluidity because it is not irradiated with ultraviolet rays or is insufficient even when irradiated. . However, according to the present invention, since the grooves 72a and 72b are formed inside the stopper portions 68a and 68b, the grooves 72a and 72b flow into the stopper portions 68a and 72b and do not flow out from the grooves. Therefore, the stopper portions 68a and 68b can exhibit their original functions. In addition, the above-mentioned caulking fixing can perform the function of positioning the yoke upper wall 60 with respect to the yoke portion 62.

FIG. 24 is a block diagram of an optical system applied to the above-described embodiment of the present invention, a control system for controlling it, and a drive system for driving it. The above-mentioned objective lens 2 is arranged close to the disc D. The return light from the disk D passes through the objective lens 2, is reflected by the mirror 50, and is guided to the integrated optical element 52. This includes a composite prism 54, a composite lens 56, and an element package 58, and the element package 58 contains a light emitting element and a light receiving element. Moreover, the electrode part 60a is attached.

The electrode section 60a is connected to the arithmetic processing IC 62, and its output is supplied to the digital signal processor 64. It supplies an output to the controller 70 and receives various control signals therefrom. The output of the digital signal processor 64 is further supplied to the drive circuit 66 and the AD / DA circuit 68.
Reproduction data is obtained from this DA circuit section. Drive circuit 6
Reference numeral 6 is connected to the electrode portion 60a of the integrated optical element 50 and is also connected to the fixed portion 4 of the objective lens driving device 1 described above, and is connected to the focus coil 7 and the tracking coils 8a and 8b via the suspension wire 5 in this device. Connected. The drive output of the drive circuit 66 is supplied to the light emitting element in the element package 58 through the electrode portion 60a described above. In this way, the configuration of the portion shown by the dotted line in FIG. 24 including the configuration shown in FIG. 1 constitutes the optical pickup device Q.

Although the embodiments of the present invention have been described above, the present invention is not limited to these, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiments, the type of disc is not particularly mentioned, but the present invention can be applied to any type of disc regardless of the type.

Further, in the first embodiment described above, the two permanent magnets 10a and 10b are attached to the yoke side walls 9b and 9c in the yoke assembly 9, but either one may be omitted. Further, the shapes of the upper ends of the yoke side walls 9b and 9c are not limited to the shapes shown in the drawings. For example, three or four bent portions 12a and 12b may be formed on each side edge portion. The same applies to the recesses 9ba and 9ca.

[0027]

As described above, according to the objective lens driving device and the optical pickup device of the present invention, the upward movement of the movable portion holding the objective lens is surely restricted, causing a large malfunction in the optical pickup device. There is no such thing. Further, it is possible to manufacture an optical pickup having excellent performance at low cost without changing the number of conventional components by only additional processing.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an objective lens driving device according to a first embodiment of the present invention.

FIG. 2 is a plan view of the same.

3 is a sectional view taken along line [3]-[3] in FIG.

FIG. 4 is a sectional view taken along line [4]-[4] in FIG.

5 is a cross-sectional view taken along line [5]-[5] in FIG.

FIG. 6 is a perspective view showing a state in which a yoke upper wall as an auxiliary yoke plate is attached to the yoke forming portion with an adhesive.

FIG. 7 is a rear perspective view of the yoke upper wall.

FIG. 8 is a cross-sectional view taken along line [8]-[8] in FIG. 5, showing the yoke upper wall as seen from below.

FIG. 9 is a perspective view of a yoke assembly in an objective lens driving device according to a second embodiment of the present invention.

FIG. 10 is a rear perspective view of a yoke upper wall of the yoke assembly.

FIG. 11 is a perspective view showing a state in which the yoke upper wall is attached to the yoke portion with an adhesive.

FIG. 12 is a vertical sectional view of the yoke assembly.

13 is a cross-sectional view taken along the line [13]-[13] in FIG.

FIG. 14 is a rear perspective view of the yoke upper wall in the yoke assembly of the objective lens driving device according to the third embodiment of the present invention.

FIG. 15 is a rear view similar to FIG.

FIG. 16 is a rear perspective view of the yoke upper wall in the objective lens driving device according to the fourth embodiment of the present invention.

FIG. 17 is a rear view similar to FIG.

FIG. 18 is a rear perspective view of the yoke upper wall of the yoke assembly in the objective lens driving device according to the fifth embodiment of the present invention.

FIG. 19 is a rear view similar to FIG.

FIG. 20 is an exploded perspective view of a yoke assembly in an objective lens driving device according to a sixth embodiment of the present invention.

FIG. 21 is an assembled perspective view of the yoke assembly.

22 is a cross-sectional view taken along line [22]-[22] in FIG.

23 is a cross-sectional view taken along the line [23]-[23] of FIG.

FIG. 24 is a block diagram of an optical system, a drive system, and a control system of the optical pickup device applied to the embodiment of the present invention.

FIG. 25 is a cross-sectional view of a main part of a conventional objective lens driving device, in which A shows a situation in which an adhesive agent is attached to a stopper portion, and B shows a situation in which a movable portion is attached thereby.

[Explanation of symbols]

1 ... Objective lens driving device, 2 ... Objective lens, 3 ...
Movable part, 4 ... Fixed part, 5 ... Suspension wire,
7 ... Focus coil, 8a, 8b ... Tracking coil, 9 ... Yoke assembly, 9a ... Yoke bottom wall, 9b, 9c ... Yoke side wall, 10a, 10b ... Permanent magnet, 11 ... Yoke upper wall, 14 ... central part, 15
a, 15b ... stopper part, 17a, 17b ... groove,
18a, 18b ... protrusion, 20 ... yoke forming portion, 2
4a, 24b ... stopper part, 25a, 25b ...
Groove, 30 ... York upper wall, 34a, 34b ... Stopper portion, 40 ... York upper wall, 42a, 42b ... Stopper portion, 44a, 44b ... Stopper portion, 50 ... York upper wall, 52a, 52b ...... Stopper part, 54a,
54b ... groove, 60 ... yoke upper wall, 62 ... yoke forming portion, 68a, 68b ... stopper portion, 72a, 72
b ... Groove, d ... Adhesive.

Claims (10)

[Claims] 1. A yoke portion made of a magnetic material having a U-shaped cross section, an auxiliary yoke plate having a stopper portion attached to an upper end surface of the yoke portion and extending outwardly from both sides of the yoke portion, and the yoke. Above the movable part by contact between the objective lens, a part of the movable part that holds the focus coil and the tracking coil, and the stopper part of the auxiliary yoke plate. In the objective lens driving device configured to limit the movement, the auxiliary yoke plate is attached to the upper end surface of the yoke portion by an adhesive or an adhesive and caulking, and is bonded inward from the stopper portion of the auxiliary yoke plate. A means for preventing agent leakage is provided, and by this means, the adhesive does not leak from the inside to a portion of the stopper portion that can come into contact with the portion of the movable portion. A drive device for an objective lens characterized by: 2. The driving of the objective lens according to claim 1, wherein the part is formed as a pair of upward projecting portions, and an upper surface thereof is higher than another upper surface of the movable portion facing the stopper portion. apparatus. 3. A recess having a U-shaped cross section is formed at an upper end of the yoke portion, and bent portions formed on both side edges of the auxiliary yoke plate engage with the recess, The objective lens driving device according to claim 1, wherein the driving device is an adhesive. 4. The objective lens driving device according to claim 1, wherein the adhesive leakage prevention means is formed as a groove or a protrusion and extends to both side edges of the auxiliary yoke plate. 5. The objective lens driving device according to claim 1, wherein the adhesive leaking means is formed as a step extending to both side edge portions. 6. An objective lens for focusing and irradiating a light beam on the optical disc for recording information on the optical disc and / or reproducing the information recorded on the optical disc, and a movable portion for holding the objective lens. , This movable part and left and right
A fixed part connected by a pair of upper and lower suspension wires, a yoke part fixed to the fixed part and made of a magnetic material having a U-shaped cross section, and a yoke part attached to the upper end surface of the yoke part. An auxiliary yoke plate having a stopper portion extending outward, a permanent magnet fixed to the yoke portion, and a magnetic flux from the permanent magnet passing through the yoke portion interact with each other to move the movable portion in the focus direction and A focus coil and a tracking coil held by the movable part for driving in the tracking direction are provided, and a part of the movable part and the stopper part of the auxiliary yoke plate are brought into contact with each other to move the movable part above the movable part. In the optical pickup device with the movement restricted, the auxiliary yoke plate is fixed to the upper end surface of the yoke portion with an adhesive or an adhesive and caulking. The adhesive leakage preventing means is provided inward of the stopper portion of the auxiliary yoke plate, and the adhesive is prevented from contacting the portion of the movable portion of the stopper portion by this means. An optical pickup device characterized in that it does not leak from the inside. 7. The optical pickup device according to claim 6, wherein the part is formed as a pair of upwardly projecting portions, and an upper surface of the portion is higher than an upper surface of the movable portion facing the stopper portion. 8. A recess having a U-shaped cross section is formed at an upper end portion of the yoke portion, and bent portions formed at both side edge portions of the auxiliary yoke plate engage with the recess portion. The optical pickup device according to claim 6, wherein the optical pickup device is adhered by an adhesive. 9. The optical pickup device according to claim 6, wherein the adhesive leakage prevention means is formed as a groove or a protrusion and extends to both side edges of the auxiliary yoke plate. 10. The optical pickup device according to claim 6, wherein the adhesive leaking means is formed as a step extending to both side edge portions.