JP2007179615A - Optical pickup - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely adjust the tilt angle of an objective lens with inexpensive structure. <P>SOLUTION: The optical pickup has a capsule 21 composed of a pair of a bottomed cylindrical capsule half bodies 21A, 21B. The capsule 21 with an adjusting spring 17 is formed by inserting the adjusting spring 17 into respective capsule half bodies 21A, 21B. The height of the capsule 21 is freely extended and contracted against the adjusting spring 17. The capsule 21 is inserted between a pressing part 20A of an optical base 1 and a receiving part 2A of an act base 2 against the adjusting spring 17 to adjust the tilt angle by the adjusting spring 17 and both tilt angle adjusting bolts 13, and the act base 2 is fixed to the optical base 1 by adhesive UV. Thereafter, the capsule 21 is pulled out against the adjusting spring 17, thereby removing the capsule 21 from between the pressing part 20A and the receiving part 2A. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to an optical pickup capable of precisely adjusting an inclination angle of an objective lens with an inexpensive structure.

Conventionally, there is a description of Patent Document 1 or the like as a technique related to an optical pickup, and an example thereof will be described based on FIGS. 8 to 10. This is a pinion (not shown) that meshes with a rack 1 a formed on one side edge. 1) and a plastic base 1 made of synthetic resin that can be reciprocated in the radial direction of the disk D by rotating it forward and backward, and a support base 1b integrally formed with the top plate 1A of the base 1 is made of metal. By engaging the projecting portion 2a integrally projecting on the lower surface of the plate-shaped act base 2 so as to be swingable, the act base 2 is disposed on the top plate portion 1A of the optical base 1 at a predetermined interval α. Yes.

An objective lens OL is disposed on a lens holder 4 that is slidably and swingably fitted to a shaft 3 that is erected substantially at the center of the act base 2, and a focus coil 5 and a magnetic piece 6 are disposed on a boss 4 a of the lens holder 4. And a pair of left and right side plate portions 2b, 2c on which the pair of magnets 8 stand up from the act base 2 with the lens holder 4 interposed therebetween. The lens holder 4 is energized through the printed wiring 9 while the lens holder 4 is floated by a magnetic spring acting between the magnet 8 and the magnetic piece 6. Is slid along the shaft 3 in the focus directions a and b, and the tracking coil 7 is energized to shuffle the lens holder 4. Tracking direction c 3 around, it is swung to d, to follow a predetermined track of the disk D.

L-shaped connecting frames 2d and 2e are integrally formed on the act base 2 at a predetermined interval, and the optical base 1 is opposed to the screw holes 11 formed at the distal ends of the connecting frames 2d and 2e. A through hole 12 is formed concentrically in the top plate portion 1A, and two inclination angle adjusting bolts 13 are screwed into the screw holes 11 of the connecting frames 2d and 2e through the through holes 12, respectively. An insertion hole 14 is formed in the seat portion 2A projecting integrally with the act base 2 at a position spaced from the both tilt angle adjusting bolts 13 by bringing the head portion 13a of the tilt angle adjusting bolt 13 into contact with the lower surface of the top plate portion 1A. The screw hole 15 is concentrically formed in the top plate portion 1 </ b> A so as to face the insertion hole 14, and one support bolt 16 is screwed into the screw hole 15 through the insertion hole 14. Between the head 16a of the support bolt 16 and the seat 2A. An adjustment spring 17 for biasing the act base 2 toward the optical base 1 by loosely fitting to the support bolt 16 is provided, and the screwing amount of each inclination adjustment bolt 13 is adjusted against the adjustment spring 17. By finely adjusting the position of the act base 2, the optical axis O1 of the objective lens OL is changed in the radial directions e and f and the tangential direction g,
The optical axis O1 of the objective lens OL is tilted to h to coincide with the optical axis O2 of the laser beam emitted from the semiconductor laser (not shown), and a plurality of locations between the act base 2 and the top plate 1A. Is filled with an ultraviolet curable adhesive UV, and the adhesive UV is irradiated with ultraviolet rays to be cured,
The act base 2 is fixed to the optical base 1. In FIG. 9, QWP is a collimating lens.
JP 2003-317265 A

In the above conventional configuration, in order to adjust the tilt angle of the objective lens OL, the support bolt 16 and the adjustment spring 17 are used in addition to the two tilt angle adjusting bolts 13, but the act base 2 is optically bonded with the adhesive UV. After fixing to the base 1, the support bolt 16 and the adjustment spring 17 become unnecessary, and the cost is increased by using them.

Therefore, after the act base 2 is fixed with the adhesive UV, it is conceivable to release the adjusting spring 17 by unscrewing the support bolt 16 with a tool such as a screwdriver. There is a possibility that the position of the act base 2 that has been finely adjusted, for example, by the tool or the support bolt 16 coming into contact with the act base 2, may be shifted, and if the position shift occurs, the tilt angle adjustment of the objective lens OL becomes meaningless. .

An object of the present invention is to provide an optical pickup capable of precisely adjusting the tilt angle of an objective lens with an inexpensive structure in view of the above-described conventional drawbacks.

In order to achieve the above object, according to the first aspect of the present invention, the act base for supporting the lens holder with the objective lens is disposed on the optical base, and the two tilt angle adjusting bolts act through the through hole of the optical base. Screwed into screw holes formed at predetermined intervals on the base,
A support bolt is screwed into the screw hole of the optical base through the insertion hole of the act base at a predetermined distance from the both tilt angle adjusting bolts, and is loosely fitted to the support bolt and attached to the optical base toward the optical base. An adjusting spring is provided, and the optical axis of the objective lens is emitted from the semiconductor laser by finely adjusting the position of the act base by adjusting the screwing amount of each inclination adjusting bolt against the adjusting spring. In the optical pickup that is aligned with the optical axis of the laser beam and the act base is fixed to the optical base with an adhesive, the support bolt is omitted, and the capsule includes a pair of bottomed cylindrical capsule halves, By inserting both ends of the adjustment spring into the capsule halves from the open ends of the capsule halves, a capsule with an adjustment spring is formed. A long hole is formed in the half body along the expansion / contraction direction, and a hook is integrally formed on the other capsule half body so as to face the long hole. The body is integrally connected, and the height of the capsule can be expanded and contracted within a certain range against the adjustment spring, and a pressing portion facing one end of the capsule with the adjustment spring is provided through the leg portion. A receiving portion that is integrally formed with the base and opposite to the other end of the capsule is integrally formed with the act base, and the height when the capsule is extended is greater than the facing distance between the pressing portion and the receiving portion. And the height at the time of reduction is set to be smaller than the facing interval, and a capsule locking recess is formed on the facing surface of the pressing portion and the receiving portion, and the capsule is used as an adjustment spring. Against the holding part and the receiving part Inserted in between, both end faces of the capsule were fitted into the respective capsule locking recesses, and the capsule was pulled against the adjustment spring to be detached from between the holding part and the receiving part. It is characterized by that.

According to the second aspect of the present invention, the act base that supports the lens holder with the objective lens is disposed on the optical base, and the two tilt adjustment bolts pass through the through hole of the optical base at a predetermined interval from the act base. Adjustment springs are provided that are screwed into the formed screw holes and bias the act base toward the optical base at a predetermined distance from both inclination angle adjustment bolts. By finely adjusting the position of the act base by adjusting the screwing amount of the adjustment bolt, the optical axis of the objective lens coincides with the optical axis of the laser beam emitted from the semiconductor laser, and the act base is fixed to the optical base with an adhesive. An optical pickup having a capsule composed of a pair of bottomed cylindrical capsule halves, wherein both ends of the adjustment spring are open to the respective capsule halves Are inserted into the respective capsule halves to form a capsule with an adjustment spring, the height of the capsule can be expanded and contracted against the adjustment spring, and a pressing portion facing one end of the capsule with the adjustment spring is provided. The optic base is integrally formed through the leg, and the receiving portion facing the other end of the capsule is integrally formed in the act base.
The capsule is adjusted so that the height when the capsule is extended is larger than the facing distance between the pressing portion and the seat and the height when the capsule is contracted is smaller than the facing distance. It is characterized in that it is inserted between the holding part and the receiving part against the spring, and the capsule is pulled out against the adjustment spring to be separated from between the holding part and the receiving part. .

According to a third aspect of the present invention, in the second aspect of the present invention, a capsule locking recess is formed on the opposing surface of the pressing portion and the receiving portion, and the pressing portion and the receiving portion It is characterized in that both end faces of the capsule inserted therebetween are fitted into the respective capsule locking recesses.

According to a fourth aspect of the invention, in the invention of the second or third aspect, a long hole is formed in the one capsule half body along the expansion and contraction direction, and the other half is opposed to the long hole. The capsule half is integrally formed with a hook, and the hook half is inserted into the long hole so that both capsule halves are connected together and the height of the capsule is expanded and contracted within a certain range against the adjustment spring. It is characterized by being possible.

The invention according to claim 1 corresponds to the second embodiment (see FIGS. 6 and 7), and according to this, the capsule with adjustment spring is received between the holding portion of the optical base and the receiving portion of the act base. It is inserted between the seat part, the tilt angle of the objective lens is adjusted, the act base is fixed to the optical base with an adhesive, and then the capsule is detached from between the holding part and the seat part. In addition, the capsule is not used as a component for an optical pickup just by using the capsule as a tilt adjustment jig, and a component corresponding to a conventional adjustment spring support bolt is unnecessary, so the adjustment spring and the support bolt are omitted. The number of parts is reduced by that amount, the structure is simple, and the production cost can be reduced.

Also, just by inserting the capsule with adjustment spring between the holding part and the receiving part, both end surfaces of the capsule are inserted into the holding part and the capsule locking recesses of the receiving part, so that the capsule is pressed. Can be reliably positioned at a desired position between the portion and the seat portion.

Furthermore, after the fixing of the act base with the adhesive, the capsule can be easily detached from between the holding part and the receiving part by simply pulling the capsule against the adjustment spring, and fine adjustment has been completed. There is no fear that the position of the act base will be mad.

In addition, by engaging the hook of the other capsule half with the long hole of one capsule half, the both capsule halves are connected together, and the height falls within a certain range against the adjustment spring. Since the capsule that can be expanded and contracted is formed, the capsule is not disassembled by the spring force of the adjusting spring, and it is easy to use.

The invention according to claim 2 corresponds to the basic form. According to this, the capsule with adjustment spring is inserted between the holding portion of the optical base and the seat portion of the act base, and the objective lens After the tilt angle is adjusted and the act base is fixed to the optical base with an adhesive, the capsule is detached from between the holding portion and the receiving portion, and the capsule is used as a tilt angle adjusting jig. It is not a component part of the optical pickup alone, and there is no need for an equivalent to the conventional adjustment spring support bolt, so the number of parts is reduced and the structure is simplified by omitting the adjustment spring and support bolt. Production costs can be reduced.

According to the third aspect of the present invention, just by inserting the capsule with the adjustment spring between the pressing portion and the receiving portion, both end surfaces of the capsule become the capsule locking recesses of the pressing portion and the receiving portion. Since it is inserted, the capsule can be reliably positioned at a desired position between the pressing portion and the receiving portion.

In addition, after fixing the act base with the adhesive, the capsule can be easily detached from between the holding part and the receiving part by simply pulling the capsule against the adjustment spring, and fine adjustment is completed. There is no fear that the position of the act base will be mad.

According to the fourth aspect of the present invention, by engaging the hook of the other capsule half with the elongated hole of one capsule half, both the capsule halves are integrally connected to the adjustment spring. On the other hand, since the capsule whose height can be expanded and contracted within a certain range is formed, the capsule is not disassembled by the spring force of the adjusting spring, and it is easy to use.

FIGS. 1 to 5 show an optical pickup according to a first embodiment of the present invention, and a substantially L-shaped frame is formed on a synthetic resin optical base 1 adjacent to a seat portion 2A of an act base 2. FIG. The body 20 is integrally projected, and the frame body 20 includes a pressing portion 20A facing the seat portion 2A, and the pressing portion 20A.
The leg portion 20B is integrally connected to the optical base 1, and the pressing portion 20A and the seat portion 2 are connected.
A capsule 21 is inserted between A and A. Since the configuration other than the above is substantially the same as the configuration shown in FIGS.

As shown in FIG. 4, the capsule 21 is made of a synthetic resin (or metal) capsule half 21.
Each of the capsule halves 21A, 21B is formed in a bottomed cylindrical shape by having an open end 21a at one end and a hemispherical end face 21b at the other end, and has outer diameters d1, d2
Are set to be the same, and both ends of the adjustment spring 17 are inserted into the capsule halves 21A and 21B from the open ends 21a of the capsule halves 21A and 21B, thereby forming the capsule 21 with the adjustment spring 17 As shown in FIG. 5A, the height m of the capsule 21 can be expanded and contracted in the directions of arrows j and k against the adjustment spring 17.

As shown in FIG. 4, the capsule halves 21A,
A capsule locking concave portion 22 having a hemispherical concave shape having a smaller diameter d3 than the outer diameters d1 and d2 of 21B is formed, and as shown in FIG. It is set so as to be larger than the facing interval t between the pressing portion 20A and the seating portion 2A and to have a height m at the time of reduction smaller than the facing interval t.

The procedure for adjusting the tilt angle will be described. As shown in FIG.
1 is pressed against the adjusting spring 17 between the holding portion 20A and the receiving portion 2A, and the hemispherical end surfaces 21b of the capsule half bodies 21A and 21B are fitted into the capsule locking recesses 22 [ FIG. 5 (a) phantom line reference]. Subsequently, the optical axis O1 of the objective lens OL is adjusted in the radial directions e and f and the tangential direction by finely adjusting the position of the act base 2 by adjusting the screwing amount of each inclination adjusting bolt 13 against the adjusting spring 17. The optical axis O1 of the objective lens OL is made to coincide with the optical axis O2 of the laser beam emitted from the semiconductor laser (not shown) by tilting to g and h,
A plurality of locations between the act base 2 and the top plate portion 1A are filled with an ultraviolet curable adhesive UV, and the adhesive UV is irradiated with ultraviolet rays to be cured. Fix it.

Thereafter, as shown in FIG. 5 (b), the capsule 21 containing the adjustment spring 17 is pulled to separate the capsule 21 from between the pressing portion 20A and the seat portion 2A.

According to the above configuration, the capsule 21 including the adjustment spring 17 is attached to the pressing portion 20 </ b> A of the optical base 1.
And the seat base 2A of the act base 2 and the tilt angle of the objective lens OL is adjusted to fix the act base 2 to the optical base 1 with the adhesive UV.
0A and the receiving portion 2A are separated from each other, and the capsule 21 is not used as a component of the optical pickup only by being used as a tilt adjustment jig, and the conventional support spring for the adjustment spring 17 is used. Since the thing corresponding to 16 is also unnecessary, the number of parts is reduced by the amount that the adjustment spring 17 and the support bolt 16 are omitted, and the structure is simple and the manufacturing cost can be reduced.

Moreover, the hemispherical end surface 21b of the capsule 21 is simply inserted between the holding portion 20A and the receiving portion 2A by inserting the capsule 21 containing the adjustment spring 17 into the capsule locking recess 22 between the holding portion 20A and the receiving portion 2A. Therefore, the capsule 21 can be reliably positioned at a desired position between the pressing portion 20A and the receiving portion 2A.

Furthermore, after the act base 2 is fixed with the adhesive UV, the capsule 21 can be easily detached from between the holding portion 20A and the receiving portion 2A simply by pulling the capsule 21 against the adjustment spring 17. This is possible, and there is no possibility that the position of the act base 2 that has been fine-tuned is out of order.

6 and 7 show the main part of the optical pickup according to the second embodiment of the present invention, and the outer diameters d1 and d2 of both capsule halves 21A and 21B are set to be different from each other. Thus, the open ends 21a of the capsule halves 21A and 21B are movably fitted to each other, and a plurality of long holes are provided at a predetermined interval (180 ° in this embodiment) in one of the capsule halves 21B. 24 is formed along the expansion / contraction directions j and k, and the distal ends of the connecting pieces 25 extending from the open end 21a of the other capsule half 21A along the expansion / contraction directions j and k so as to face the long holes 24. The hooks 26 are integrally formed with each other, and the capsule halves 21A and 21B are integrally connected by fitting the hooks 26 into the long holes 24, and the height m of the capsule 21 is adjusted. Spring 17 And it is capable of within a certain range expansion and. Since the configuration other than the above is substantially the same as that of the first embodiment shown in FIGS. 1 to 5, the same parts are denoted by the same reference numerals and the description thereof is omitted.

The procedure for adjusting the tilt angle will be described. As shown by a solid line in FIG. 7, the grasped capsule 21 containing the adjustment spring 17 is pushed between the pressing portion 20A and the seat portion 2A, and as shown by a virtual line in FIG. Then, both hemispherical end faces 21b of the capsule 21 are engaged with the respective capsule locking recesses 22, and then the tilt angle is adjusted in the same procedure as in the first embodiment, and then the act base 2 and the top plate portion The act base 2 is fixed to the optical base 1 by filling the UV curable adhesive UV with a plurality of locations between the optical base 1A and irradiating the adhesive UV with ultraviolet rays to be cured.

Thereafter, as shown by a solid line in FIG.
1 is separated from between the holding portion 20 </ b> A and the receiving portion 2 </ b> A against the adjustment spring 17.

According to the above configuration, substantially the same effect as that of the first embodiment (see FIGS. 1 to 5) can be obtained. In particular, the other capsule half 21A is inserted into the long hole 24 of one capsule half 21B. By engaging the hook 26, both capsule halves 21 </ b> A and 21 </ b> B are integrally connected to form the capsule 21 that can extend and contract within a certain range in height m against the adjustment spring 17. Therefore, the capsule 21 is not disassembled by the spring force of the adjustment spring 17 and is easy to use.

It is a top view which shows the optical pick-up which is the 1st Embodiment of this invention. It is the same part notch side view. It is an AA arrow line view of FIG. It is a disassembled perspective view of the principal part. (A) is the longitudinal cross-sectional view of the principal part which shows the insertion procedure of the capsule, (b) is the cross-sectional view of the principal part which shows the removal procedure of the capsule. (A) is a disassembled perspective view which shows the principal part of the optical pick-up which is the 2nd Embodiment of this invention, (b) is a perspective view of the principal part. It is a longitudinal cross-sectional view of the principal part which shows the procedure of insertion and removal of the capsule. It is a top view which shows a prior art example. It is the longitudinal cross-sectional view. It is a BB arrow line view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Opti base 2 Act base 2A Seat part 4 Lens holder 11 Screw hole 12 Through hole 13 Inclination adjustment bolt 16 Support bolt 17 Adjustment spring 20A Holding part 21 Capsule 21A, 21B Capsule half 21a Capsule half opening 22 Capsule engagement Recessed recess 24 Long hole 26 Hook OL Objective lens UV UV curable adhesive O1 Optical axis of objective lens O2 Optical axis of laser beam

Claims (4)

An act base that supports the lens holder with the objective lens is disposed on the optical base, and 2
The two tilt adjustment bolts are screwed into the screw holes formed at predetermined intervals in the act base through the through holes of the optical base, and the act base insertion holes are formed at positions spaced from the both inclination adjustment bolts by a predetermined interval. A support bolt is screwed into the screw hole of the optical base, and an adjustment spring that is loosely fitted to the support bolt and biases the act base toward the optical base is provided.
By adjusting the screwing amount of each tilt adjustment bolt against the adjustment spring and finely adjusting the position of the act base, the optical axis of the objective lens is made to coincide with the optical axis of the laser beam emitted from the semiconductor laser. In the optical pickup in which the base is fixed to the optical base with an adhesive, the support bolt is omitted, the capsule includes a pair of bottomed cylindrical capsule halves, and both ends of the adjustment spring are connected to the capsules. By inserting into each capsule half from the open end of the half, a capsule with an adjustment spring is formed, and a long hole is formed in the one capsule half along the direction of expansion and contraction, and is opposed to the long hole. Then, a hook is integrally formed on the other capsule half, and by inserting the hook into the long hole, both the capsule halves are connected together, and the height of the capsule is increased. A holding portion that is capable of expanding and contracting within a certain range against the adjusting spring and that is opposed to one end of the capsule with the adjusting spring is formed integrally with the optical base via the leg portion, and is opposed to the other end of the capsule. A receiving part is formed integrally with the act base, and the height when the capsule is extended is larger than the facing distance between the pressing part and the receiving part, and the height when the capsule is reduced is smaller than the facing distance. A concave portion for capsule locking is formed on the opposing surface of the pressing portion and the receiving portion, and the capsule is inserted between the pressing portion and the receiving portion against the adjustment spring. In addition, both end faces of the capsule are fitted into the respective capsule locking recesses, and the capsule is pulled against the adjustment spring to be detached from between the pressing portion and the receiving portion. Optical pickup. An act base that supports the lens holder with the objective lens is disposed on the optical base, and 2
The two tilt adjustment bolts are screwed into the screw holes formed at predetermined intervals in the act base through the through holes of the optical base, and the act base is turned into the optical base at a position spaced from the both tilt adjustment bolts by a predetermined interval. An adjustment spring that urges toward the end is provided, and the position of the act base is finely adjusted by adjusting the screwing amount of each inclination adjustment bolt against the adjustment spring, thereby adjusting the optical axis of the objective lens to the semiconductor laser. In the optical pickup in which the act base is fixed to the optical base with an adhesive so as to coincide with the optical axis of the laser beam emitted from the capsule, the capsule includes a pair of bottomed cylindrical capsule halves, By inserting both end portions into the respective capsule halves from the open ends of the respective capsule halves, a capsule with an adjustment spring is formed, and the height of the capsule is adjusted. The holding part facing the one end of the capsule with the adjustment spring is formed integrally with the optical base via the leg part, and the receiving part facing the other end of the capsule is acted. It is integrally formed with the base, and the height when the capsule is extended is set to be larger than the facing interval between the pressing portion and the receiving portion, and the height when the capsule is reduced is set to be smaller than the facing interval. The capsule is inserted between the holding part and the receiving part against the adjustment spring, and pulled out against the adjusting spring so that the capsule is detached from between the holding part and the receiving part. An optical pickup characterized by Capsule locking recesses are formed on the opposing surfaces of the pressing part and the receiving part, and both end surfaces of the capsule inserted between the pressing part and the receiving part are fitted into the capsule locking recesses. The optical pickup according to claim 2, wherein the optical pickup is configured as described above. A long hole is formed in the one capsule half along the expansion / contraction direction, and a hook is integrally formed on the other capsule half facing the long hole, and the hook is fitted into the long hole. 4. The optical pickup according to claim 2, wherein both the capsule halves are integrally connected, and the height of the capsule can be expanded and contracted within a certain range against the adjustment spring. .

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