JPH0916976A - Objective lens driving device and jig for assembling the same - Google Patents

Abstract

(57) [Abstract] [Purpose] The work of assembling the carriage assembly to the base is simplified, and it is not necessary to remove the carriage assembly from the base when replacing parts. [Structure] The magnetic circuit units 31 and 32 are attached to the base 18. The magnetic circuit units 31 and 32 have yokes 23 and 26, coils 25 and 28, and magnets 24 and 27. The carriage 10 is divided into a lens support portion 11 that supports the objective lens 12 and moving portions 13 and 14. The moving parts 13 and 14,
It is attached to the guide rails 21 and 22 connected to the yokes 23 and 26. The lens supporting portion 11 is connected to the moving portions 13 and 14 with screws 46. The moving parts 13 and 14 move along the guide rails 21 and 22 by the electromagnetic force generated in the magnetic circuit parts 31 and 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk having an objective lens for optically recording information on an optical disk medium such as a magneto-optical disk or reproducing the information optically in a magneto-optical disk apparatus. The present invention relates to an objective lens driving device that moves along a surface of a medium.

[0002]

2. Description of the Related Art Conventionally, an objective lens driving device of this type guides a carriage supporting the objective lens in a radial direction of an optical disk medium by a pair of guide rails, and an electromagnetic force generated in the magnetic circuit for the carriage. Is used to displace the optical disc medium to an arbitrary position from the inner circumference to the outer circumference. The magnetic circuit has a magnet, a yoke provided around the magnet, and a pair of coils movably fitted in a part of the yoke. These coils are orthogonal to the moving direction of the carriage. It is connected to both sides of the direction.

In the process of assembling the objective lens driving device, coils are first connected to predetermined positions on both sides of the carriage, and then the carriage is attached to guide rails to form an assembly. Further, the coil of this assembly is fitted to a part of another assembly composed of a magnet and a yoke to be assembled as a carriage assembly. Finally, the guide rail and the yoke of the carriage assembly are fixed to the base of the optical disc device, respectively, to complete the objective lens driving device. At this time, the clearance between the coil and the yoke is always ensured within a certain range so that the carriage can move smoothly over the entire moving range, and the pair of guide rails have a predetermined parallelism. , And that the carriage and the guide rail maintain a predetermined positional relationship.

[0004]

However, in the carriage assembly as described above, the base is so arranged that the positional relationship between the coil and the yoke and the carriage and the guide rail maintains a predetermined relationship over the entire movement range of the carriage. The assembling work is complicated, and it has been desired to simplify this assembling work. Even if a part of the components of the carriage assembly is replaced, the entire carriage assembly must be removed from the base once, and the above-mentioned positional relationship must be maintained when reassembling the carriage assembly after the parts replacement. This had to be done with due consideration, and the replacement work was not easy.

An object of the present invention is to provide an objective lens driving device which simplifies the work of assembling the carriage assembly to the base and does not require the carriage assembly to be removed from the base when replacing parts.

[0006]

SUMMARY OF THE INVENTION An objective lens driving device according to the present invention includes a base, a carriage for supporting the objective lens, a magnetic circuit portion attached to the base for electromagnetically driving the carriage, and a carriage. The objective lens is divided into a lens supporting portion provided with the objective lens and a moving portion which is displaced by receiving an electromagnetic force generated by the magnetic circuit portion. And the moving part are connected to each other by a connecting means.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is an exploded perspective view showing an objective lens driving device according to a first embodiment of the present invention, showing a state in which an objective lens supporting portion 11 of a carriage 10 is detached from an apparatus main body.

This objective lens driving device is provided in, for example, a magneto-optical disc device, and optically information is recorded on a recording surface of a magneto-optical disc (not shown) via an objective lens 12 supported by a lens supporting portion 11. Is recorded, or the information is optically reproduced. Since the objective lens 12 needs to move in parallel to the magneto-optical disk and in the radial direction from the inner circumference to the outer circumference of the disk, a pair of guide rails 21 and 22 for this purpose are arranged along the radial direction of the magneto-optical disk. It is laid parallel to.

The carriage 10 is divided into a lens supporting portion 11 provided with an objective lens 12 and a pair of moving portions 13 and 14, and the moving portions 13 and 14 are each a guide rail 2.
1 and 22 are movably supported. Guide rail 2
1 is located outside the center yoke 23 that is connected to the U-shaped back yoke 31 and forms a rectangular frame shape, and is fixed to both ends of the back yoke 31 by metal pressing plates. A magnet 24 is bonded to the inner wall of the back yoke 31 that faces the center yoke 23. A coil 25 is movably fitted in the center yoke 23. Similarly, the guide rails 22 are located outside the center yoke 26 and are fixed to both ends of a U-shaped back yoke 32. The inner wall of the back yoke 32, which is a surface facing the center yoke 26, is fixed to the guide rail 22. Magnet 27
And a coil 28 is loosely fitted to the center yoke 26. The center yokes 23 and 26 are fixed to both ends of the back yokes 31 and 32 with screws or the like, and the back yokes 31 and 32 are fixed to the base 18 with screws or the like.

The moving parts 13 and 14 have coils 25 and 25, respectively.
It is connected to 28. On the other hand, the magnets 24 and 27 are both divided into N-poles and S-poles on a plane parallel to the bonding surface with the back yokes 31 and 32. As a result, from the pole on the side where the magnet is attached to the magnet, it passes through the back yoke and reaches the inside of the center yoke. An annular magnetic field reaching the poles is generated. Therefore coil 2
By energizing 5 and 28, an electromagnetic force perpendicular to the magnetic field is induced in the portion sandwiched between the magnet of each coil and the center yoke, whereby the carriage 10 is electromagnetically driven,
It is displaced along the guide rails 21 and 22. That is, the coils 25 and 28, the yokes 23 and 26, the back yoke 3
1, 32 and the magnets 24 and 27 constitute each magnetic circuit portion, and the guide rails 21 and 22 include the magnetic circuit portion 3.
It is fixed to Nos. 1 and 32.

The moving portion 14 has a circular hole 15, and the circular hole 15 is fitted in the guide rail 22. Moving unit 14
Is provided with a guide roller 43 that rolls along the guide rail 22, and a guide roller (not shown) is also provided below the guide roller 43. Similarly, the other moving portion 13 has a circular hole (not shown), and this circular hole is fitted to the guide rail 21. In addition, a guide roller 41 that rolls along the guide rail 21 is attached to the moving portion 13.
42 is provided, and a guide roller (not shown) is also provided below these guide rollers.

The moving portion 14 is provided with a connecting plate 16 which projects toward the other moving portion 13 side, and the connecting plate 16 has the screw hole 1
6a are formed. The other moving portion 13 has a similar structure and is provided with a pair of connecting plates 17 having screw holes 17a. On the other hand, the lens support 11 includes a connecting plate 16,
Connecting plates 44 and 45 are formed at positions corresponding to 17, and holes 44a and 45a are formed in these connecting plates 44 and 45. Therefore, the connecting plate 44 and the moving unit 14
Of the connecting plate 16 and the connecting plate 45 and the moving part 1
In a state where the connecting plate 17 of No. 3 is superposed, the holes 44a, 45
The lens support portion 11 is integrally connected to the moving portions 13 and 14 by screwing the screw 46 into the screw holes 16a and 17a.

Next, the assembly of the apparatus of this embodiment will be described. First, the center yokes 23 and 26 are attached to the moving portion 13,
The coils 14 and 14 are fitted into the adhered coils 25 and 28, respectively, and then fixed to the back yokes 31 and 32. Next, in addition to the circular holes 15 of the moving parts 13 and 14, the guide rails 21 and 2
2 is inserted and these guide rails 21 and 22 are fixed to the back yokes 31 and 32. The assembly thus obtained is attached to a base 18 fixed to a housing (not shown) of the magneto-optical disk device. At this time, the center yokes 23 and 26 are positioned so that the guide rails 21 and 22 and the center yokes 23 and 26 are separated from each other by a predetermined distance and the parallelism thereof has an accuracy of a predetermined value or more. Next, the pair of moving parts 13 and 14 are moved along the guide rails 21 and 22 and positioned so as to face each other. The connecting plates 44 and 45 of the lens supporting portion 11 are moved by the moving portions 13 and 1,
4 is mounted on the connecting plates 17 and 16, and the screw 46 is provided with a hole 44.
a, 45a and screw holes 16a, 17a.

As described above, in this embodiment, the carriage 10 is divided into the lens supporting portion 11 and the moving portions 13 and 14, and the first assembly includes the moving portion 13, the guide rail 21, the center yoke 23, the back yoke 31 and the like. And the moving part 1
4, the guide rail 22, the center yoke 26, the second assembly including the back yoke 32, and the like are attached to the base 18, and then the lens support portion 11 is moved to the moving portions 13 and 14.
It is configured to be attached to. Therefore, the carriage 10, the guide rails 21 and 22, and the magnetic circuit unit 3
The work for assembling to the base 18 while maintaining the predetermined positional relationship between the first and the second parts is unnecessary, which is extremely simple. Also, when exchanging components such as the objective lens 12,
The lens support 11 may be removed from the moving parts 13 and 14 by loosening the screw 46, and the lens support 11 may be attached to the moving parts 13 and 14 after the objective lens 12 is replaced. That is, unlike the prior art, the positioning work of the parts such as the back yokes 31 and 32 is unnecessary, and therefore the replacement work of the objective lens 12 and the like is easy.

FIG. 2 is an exploded perspective view showing the second embodiment. Coils 25 and 28 loosely fitted to the yokes 23 and 26
Are connected by a plate-shaped moving portion 51, and the moving portion 51 is provided with four screw holes 51a. On the other hand, a hole 52a is formed in the lens supporting portion 52 at a position corresponding to the screw hole 51a of the moving portion 51. Also, the lens support 5
2 has a pair of circular holes 53, 54, and each circular hole 5
Guide rails 21 and 22 are inserted into 3 and 54, respectively. The lens support portion 11 is provided with guide rollers 41 and 42 that roll on one of the guide rails 21,
Further, a guide roller 43 rolling on the other guide rail 22 is provided. That is, the lens support portion 52 is movably supported by the guide rail.

The assembly of the second embodiment is performed as follows. That is, the coils 25 and 28 to which the moving portion 51 is connected are loosely fitted to the yokes 23 and 26 and attached to the base (not shown). Then, the guide rail 21,
The lens moving part 52 in which 22 is inserted is placed on the moving part 51, and the screw 46 is screwed into the hole 52a and the screw hole 51a. Both ends of the guide rails 21 and 22 are fixed to the base.

Therefore, according to the second embodiment, the relative positioning of the yokes 23 and 26 is simplified and the positioning of the moving portion 51 on the guide rails 21 and 22 is unnecessary as compared with the first embodiment. As a result, the assembling work of the objective lens driving device becomes easier.

FIG. 3 is an exploded perspective view showing the third embodiment. This figure corresponds to the case where the device of the second embodiment is viewed from the opposite side of FIG. 2, that is, the arrangement of the guide rails 21, 22 and the like is the opposite of that in FIG.

The guide rollers 41 and 42 roll on one guide rail 21, and the guide roller 43 rolls on the other guide rail 22. The moving unit 51 is provided with a pressing roller 56 via a leaf spring 55. Pressing roller 5
6 is pressed against the surface of the guide rail 22 by the leaf spring 55, so that the moving portion 51 is moved to the guide rail 21 on one side.
Always urged to the side. Therefore, the moving portion 51 and the lens supporting portion 52 (that is, the carriage) are always provided with the guide rail 2.
It will be guided and moved by 1 and guide rail 2
The error of parallelism of 1 and 22 is absorbed. Other configurations and effects are similar to those of the second embodiment.

FIG. 4 is a perspective view showing a fourth embodiment. This embodiment is an assembling jig 61, which is, for example, the assembling process of the apparatus of the first embodiment, that is, the moving unit 13,
When assembling the magnetic circuit portions 31 and 32 to which 14 is attached and the lens support portion 11 to the base 18 (see FIG. 1),
It is used as a guide member that determines the relative positions of the moving portions 13 and 14 and the lens support portion 11, and is removed from the base 18 after the assembly process is completed.

The assembling jig 61 is constructed by projecting first to third guide pins 63, 64 and 65 on the upper surface of a flat plate 62. The first guide pin 63 located at the center can be engaged with a positioning recess (not shown) formed in the lower surface of the lens support 11. The second and third guide pins 64 and 65 located on both sides of the first guide pin 63 are engageable with positioning recesses (not shown) formed on the lower surfaces of the moving portions 13 and 14. First to third guide pins 63, 6
Reference numerals 4 and 65 are formed at positions such that the lens supporting portion 11 and the moving portions 13 and 14 are attached to the base in a predetermined positional relationship, and the flat plate 61 is formed in the housing in the assembly process of the objective lens driving device. It is placed in place. To fix the flat plate 61 to the housing, the flat plate 6
Holes 66 for mounting screws are formed at the four corners of 1.

According to this embodiment, when the moving parts 13 and 14 and the lens supporting part 11 are assembled, the accuracy of their relative positions can be improved, and the positioning work can be simplified.

[0023]

As described above, according to the present invention, the work of assembling the carriage assembly to the base is simplified,
Further, there is an effect that it is not necessary to remove the carriage assembly from the base when replacing the parts.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an objective lens driving device according to a first embodiment of the present invention, showing a state in which a lens supporting portion of a carriage is removed from a main body of the device.

FIG. 2 is an exploded perspective view showing a second embodiment.

FIG. 3 is an exploded perspective view showing a third embodiment.

FIG. 4 is a perspective view showing a fourth embodiment.

[Explanation of symbols]

 10 Carriage 11 Lens Support Part 12 Objective Lenses 13 and 14 Moving Part 18 Bases 21 and 22 Guide Rails 31 and 32 Magnetic Circuit Part 46 Screws (Connecting Means)

Claims (6)

[Claims] 1. An objective lens driving device provided in an optical information recording / reproducing device for moving an objective lens along a recording medium, comprising: a base, a carriage supporting the objective lens, and a base mounted on the base. A magnetic circuit part for electromagnetically moving the carriage and a guide rail for movably supporting the carriage, wherein the carriage comprises a lens support part provided with the objective lens, and a magnetic circuit part. An objective lens driving device characterized in that the objective lens driving device is divided into a moving part that is displaced by receiving an electromagnetic force generated, and the lens supporting part and the moving part are connected to each other by a connecting means. 2. The objective lens driving device according to claim 1, wherein the guide rail is fixed to the magnetic circuit unit. 3. The objective lens driving device according to claim 1, wherein the guide rail movably supports the lens support portion. 4. The objective lens driving device according to claim 3, wherein a biasing member that presses the lens support portion against the surface of the guide rail is provided in the moving portion. 5. The objective lens driving device according to claim 1, wherein the connecting means is a screw. 6. A guide member, which is used when assembling the magnetic circuit part to which the moving part is attached and the lens supporting part to the base, and which determines a relative position between the moving part and the lens supporting part. An assembling jig for assembling the objective lens driving device according to claim 1.