KR100357919B1 - Optical pickup and mrthod for assembling the same - Google Patents

Abstract

It is a carriage made of sheet metal with low cost, which fixes the light transmitting part with high precision, and provides optical pickup and assembly method with little change even in the change of the surrounding environment.

Box-shaped carriage 12 made of sheet metal, a pair of second cut pieces 31 formed by cutting a portion of the bottom plate of the carriage 12, and the second cut pieces ( 31, a predetermined gap is formed to arrange the light transmitting part 18, the positioning of the light receiving part 18 is adjusted, and the light transmitting part 18 is made to pass through the adhesive 13 to the first agent. 2 It is cut and attached to the upright piece 31.

Description

Optical pickup and assembly method {OPTICAL PICKUP AND MRTHOD FOR ASSEMBLING THE SAME}

The present invention relates to an optical pickup suitable for an optical disk device using an optical disk such as a magneto-optical disk and an assembly method thereof.

The optical pickup is attached to the optical disk apparatus to inject laser light into the optical disk to record information on or reproduce the recorded information on the disk surface.

In Fig. 9, a conventional optical pickup 50 is provided with a carriage 51 attached to an optical disk device for reciprocating motion, a light transmitting portion 18 attached to the carriage 51, and a light transmitting portion 18. A flexible substrate 19 and a circuit board 21 for supplying signals, and a cover 55 covering the circuit board 21.

The transmissive light receiving portion 18 is provided with a jaw-shaped stem portion 23a integrally formed with the metal main body 23, and includes a light emitting element such as a laser diode and a light receiving element such as a photodiode, and the like in the main body 23. Optical components, such as a prism, are accommodated.

On both sides of the stem portion 23a, gently curved surfaces 25 are formed, and on the bottom portion 18b, a plurality of terminals 100 of the light emitting element and the light receiving element protrude outward. The front face of the stem portion 23a, which is the opposite side of the bottom portion 18b, serves as an attachment reference surface for attaching the light transmitting portion 18 to the carriage 51.

And on the side opposite to the terminal 100 of the main body 23, the light transmission surface 33 which formed the window part which a laser beam enters and exits is formed.

Electronic components (not shown) are soldered to the surface of the circuit board 21, and groove portions 60 formed by cutting a part thereof are formed in the peripheral portion thereof. The terminal 100 and the circuit board 21 are made to conduct by inserting and passing the terminal 100 of the light receiving part 18 into the groove part 60 of the circuit board 21. The circuit board 21 constitutes a circuit for stably driving the light emitting element of the light transmitting part 18.

The cover 55 is a box-shaped member formed by bending a metal plate to have one opening, and both sides of the cover 55 are provided with a locking portion 61 which is cut and bent a portion.

Then, a part of the flexible substrate 19 and the circuit board 21 are attached to the bottom portion 18b side of the main body 23 described above, and the cover 55 is fitted to the stem portion 23a of the light receiving portion 18. It is touched and covered.

The carriage 51 is formed by die-casting a metal material such as aluminum into a relatively thick box shape. The carriage 51 has two different lengths extending from the main body 62 at regular intervals in the same direction. It consists of arm parts 63a and 63b.

And inside the both arm parts 63a and 63b, the recessed part 66 is formed in proximity to the edge part 65 and this edge part 65, respectively. In the end portion 65, a gently curved groove portion 67 is formed, and one surface of the groove portion 67 serves as an attachment reference surface of the light transmitting portion 18. As shown in FIG.

And the attachment hole 68 is formed in the inside of the recessed part 66, and the notch groove 64 is formed in the front-end | tip part of the long arm part 63a.

And in the center part of the main body 62, the recessed part 70 formed in the groove shape along the extension direction of the arm parts 63a and 63b is formed. In the center of the recess 70, a triangular prism 73 having an inclined surface 73a serving as an attachment reference surface is integrally formed with the main body 62.

The flat mirror 40 is appropriately fixed to the inclined surface 73a of the protrusion 73 of the carriage 51 by an adhesive or the like.

Moreover, by forming the recessed part 70 in the main body 62, the thin wall part 71 which connects the arm parts 63a and 63b between the arm parts 63a and 63b is integrated with the main body 62 integrally. Formed. And the round hole 72 penetrates and is formed in the center of the wall part 71. As shown in FIG.

The carriage 51 is fixed with an objective lens (not shown) disposed immediately above the projection 73.

In the case of assembling the light receiving portion 18 in the carriage 51, the curved portion 25 of the light transmitting portion 18 is fitted into the groove portion 67 of the carriage 51, so that the stem portion 23a is formed. While finely adjusting the attachment position of the light receiving portion 18 while pressing the front surface against the attachment reference surface of the groove portion 67, fixing it with an adhesive or the like and then covering the cover 55 from the rear side and covering the attachment hole 68. The locking portion 61 of the 55 is made to snap.

Subsequently, in order to assemble the mirror 40 to the carriage 51, an ultraviolet curable adhesive or the like is applied to the rear surface of the mirror 40 to fix the mirror 40 to the inclined surface 73a of the protrusion 73 accurately. have.

In the carriage 51, a shaft rod (not shown) is arranged in the notch groove 64 so that the carriage 51 moves along the shaft rod in the optical disc apparatus so as to conform to the recording surface of the optical disc.

In the optical pickup 50 configured as described above, the laser light emitted from the light transmission surface 33 of the light transmission portion 18 passes through the round hole 72 of the wall portion 71 and again passes through the mirror 40 and is at right angles. Is reflected and is incident on the objective lens 14 shown in FIG.

Thus, the carriage 51 of the said prior art example uses the aluminum die-casting which has high rigidity, and can process it with high precision, and when assembling the light receiving part 18 which requires assembly precision, the machining surface of this aluminum die-casting is carried out. It is assembled on the basis of However, the price of aluminum die-casting itself was high, causing a cost increase.

Therefore, when the carriage 51 is assembled in the same structure as the conventional optical pickup 50 by replacing the carriage 51 with a low-cost sheet metal in aluminum diecast, in the recent request for cost reduction, 18), there is a problem that the precision of the sheet metal cannot be obtained, and that the carriage 51 is deformed and the positioning accuracy cannot be obtained simply by the method of adjusting the positioning by attaching the plate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical pickup and a method for assembling the same, which can accurately fix the light transmitting part even using a carriage made of sheet metal having low cost.

1 is a perspective view of an optical pickup according to the present invention.

2 is an enlarged perspective view of a part of the optical pickup in a state in which the second side wall portion of the present invention is removed;

3 is a partially enlarged plan view of an optical pickup according to the present invention;

4 is a perspective view of a carriage of an optical pickup according to the present invention;

5 is a perspective view showing a state in which a mirror is attached to a carriage of an optical pickup according to the present invention.

Fig. 6 is a partially enlarged perspective view showing the assembly of a light transmitting portion and a holder of an optical pickup according to the present invention;

7 is a plan view of an optical pickup according to the present invention.

Fig. 8 (a) is a sectional view near the center of a carriage schematically shown in the optical pickup according to the present invention, and Fig. 8 (b) is a perspective view showing a jig for assembling a mirror.

9 is a partially perspective view of a conventional optical pickup;

* Description of the symbols for the main parts of the drawings *

10: optical pickup 12: carriage

13: bonding means 18: light transmitting part

31: bending piece (second cut-up piece)

As a first solution for solving the above problems, a carriage made of sheet metal, a bending piece bent a portion of the carriage, and a predetermined gap are formed between the bending pieces to arrange a light transmitting part. The light transmitting part is attached and fixed to the bent piece through an adhesive means.

And as a 2nd solution means, a bending piece consists of a pair of bending pieces arrange | positioned opposingly, and it cuts and stands in the opposite direction mutually, It is characterized by the above-mentioned.

And as a 3rd solution means, the clearance of the cross section of a bending piece and a light transmission part is set to 200 micrometers or less.

As a fourth solution, the assembling method according to the present invention forms a bent piece in which a part of the carriage made of sheet metal is bent in opposite directions to each other, and a gap is formed in the space of the bent piece using a jig. It forms, arrange | positions, adjusts the positioning of a light transmission part, and fixes a light transmission part to the bending piece using the adhesion means.

Embodiment of the invention

An optical pickup that is an embodiment of the present invention will be described below with reference to the drawings of FIGS. 1 to 8.

1 is a perspective view of an optical pickup 10 according to the present invention.

As shown in FIG. 1, the optical pickup 10 includes a lens actuator 110 having an objective lens 14 housed in a carriage 12 made of metal sheet metal, and a mirror 40 with the objective lens 14. Permeable light portion 18 for emitting a laser beam through the light and incident the return light from the objective lens 14, a holder 20 for supporting the light-transmitted light portion 18, and covering the holder 20. The cover 22 is comprised.

4 is a perspective view showing the carriage 12 of the optical pickup 10 according to the present invention.

As shown in FIG. 4, the carriage 12 has the flat plate-shaped bottom plate part 24 which consists of rectangular metals, and the 1st side wall part provided facing each other along the longitudinal edge of this bottom plate part 24, respectively. And a second side wall portion 27. One end of the first and second side wall portions 26 and 27 protrudes from the bottom plate portion 24.

And the 3rd side wall parts 29 and 29 which were installed upright similarly to the 1st, 2nd side wall parts 26 and 27 are provided in the bottom plate part 24 with a fixed space in the longitudinal direction of this side wall parts 26 and 27. As shown in FIG. And are formed integrally with each other.

In the third side wall portions 29 and 29, penetrating round holes 30 are formed to have a size through which one shaft rod not shown is inserted.

The notch groove 28 is formed in the front-end | tip of the 1st side wall part 26. As shown in FIG.

Subsequently, the bottom plate part 24 is formed with a substantially rectangular opening 36, and a pair of first cut pieces 38 formed to face each other are formed in a part of the edge portion facing the opening 36. The opposing surface is a side wall surface 38b.

An approximately rectangular cutout 39 is formed at the outer edge portion of the bottom plate portion 24. At the edges on the opposite sides of the cutouts 39, there are formed bent pieces, that is, second cut-up pieces 31, which are formed so as to face the first and second sidewall portions 26 and 27, respectively. .

The second cutting piece 31 is formed by bending from the bottom plate portion 24 in the opposite direction to each other by a bending jig (not shown) and is bent at almost right angles.

In the remaining edge portion of the cutout portion 39, a substantially convex support portion 42 having a sidewall surface in a direction orthogonal to the opposite sidewall surface 31b of the second cut piece 31 is provided. It is formed upright.

A round hole 72 penetrates through the center of the base 42.

Subsequently, a flat end face 31a is formed in each of the second cut pieces 31 at right angles to the side wall surface 31b.

And the holder 20 which supports the light transmission part 18 shown in FIG. 1 is attached to this end surface 31a.

Subsequently, in each of the first cut pieces 38, an inclined portion 38a formed by obliquely cutting one corner portion of the side wall surface 38b is formed, and is precisely formed to prevent scratches and the like.

And the mirror 40 mentioned later is assembled between the side wall 38b of FIG. 1 of the 1st cutting piece 38 in the inclined part 38a side.

5 is a perspective view showing a state in which the mirror 40 is attached to the carriage 12 of the optical pickup 10 according to the present invention.

The mirror 40 shown in FIG. 5 is a rectangular plate in which a metal film is deposited on optical glass or an optical resin member.

The side wall part 40a and the surface part (or back part) 40b of this mirror 40 are processed with high precision.

That is, the surface portion 40b reflects the laser beam so as to emit the incident laser beam at a predetermined angle at a predetermined angle, and the side wall portion 40a is a side wall surface 38b of the first cut piece 38: 2) is attached.

Fig. 6 is a perspective view showing a holder 20 for supporting the light transmitting portion 18 and the like of the optical pickup 10 according to the present invention.

As shown in Fig. 6, the light transmitting part 18 is formed with a jaw-shaped stem portion 23a integrally formed with the metal main body 23. In the main body 23, a light emitting element such as a laser diode and the like are formed. A light receiving element such as a photodiode and an optical component such as an integrated prism are housed.

On the left and right sides of the stem portion 23a, smoothly curved curved portions 25 are formed, and at the rear portion thereof, the terminal 100 of the light emitting element and the light receiving element protrudes plural outwardly (in Fig. 6, inward direction). It is.

In addition, the front surface of the stem portion 23a serves as an attachment surface for attaching the light receiving portion 18 to the carriage 12.

The front surface of the metal main body 23 is a light transmission surface 33 on which the window portion 33a through which the laser light enters and exits is formed.

The holder 20 is die cast or mold-molded, and includes an opposingly arranged side wall portion 16, a jaw portion 4a formed at one end of the side wall portion 16, and a bottom wall portion 17. Consists of.

A curved opening 15 is formed in the jaw portion 4a, and the curved surface portion 25 of the stem portion 23a of the light receiving portion 18 has an adhesive means such as an adhesive 13 in the opening 15. 7) to be fitted using.

A circuit board 21 having electronic components is disposed between the side wall portions 16 of the holder 20 to form a high frequency superimposed circuit.

In the edge portion of the circuit board 21, a groove portion 60 is formed, a part of which is cut off, and the terminal 100 of the light receiving portion 18 is inserted into the groove portion 60 to be soldered and fixed, whereby the terminal 100 and The circuit board 21 is made to conduct.

2 is a partially enlarged perspective view in a state in which the second side wall portion 27 of the optical pickup 10 according to the present invention is removed.

The cover 22 is a metal box-shaped member having one opening, which covers the entire holder 20 from the opening, and shows a holder hook portion 22a protruding toward the opening side of the cover 22 in FIG. 6. It fits in the attachment hole 45 of the 20, and is fixed by bending the front-end | tip part of the attachment hook part 22a after that.

As shown in FIG. 1, two holes 46 for positioning adjustment are formed side by side on the side wall facing the opening of the cover 22.

Subsequently, as shown in FIG. 1, the lens actuator 110 is supported by the actuator base 111 and the actuator base 111 with flexibility, the lens holder 112 having the objective lens 14, and The yoke 113 is integrated with the lens holder 112.

And the actuator base 111 is comprised so that attachment and fixation may be carried out on the opening part 36 (FIG. 2) of the carriage 12 shown in FIG.

Next, assembly of each component is demonstrated.

FIG. 8 (a) shows a cross-sectional view near the center of the carriage 12 schematically shown in the optical pickup 10 of the present invention, and FIG. 8 (b) shows the assembly of the mirror 40 on the carriage 12. The perspective view which showed the jig | tool for this is shown.

First, the jig for assembling the mirror 40 to the carriage 12 will be described.

In Fig. 8 (b), roughly cuboid protrusions 152a, 152b, 152c, and 152d are formed integrally with the base 151 at the four corners of the flat base 151 of the jig. In the projections 152a, 152b, 152c, and 152d, end portions 153 notched in part are formed in the outward direction, among which the ends of the projections 152a, 152b are formed. The engaging portions 154 and 154 are fixed to 153, respectively.

Further, an elongated cylindrical shaft bar 155 is attached between the end portions 153, 153 of the projections 152a, 152b and pressed by the locking portions 154, 154.

This shaft rod 155 has the same diameter as the shaft rod used when the optical pickup 10 is attached to the disk apparatus.

In the central portion of the upper surface of the base 151, a protrusion 156 having a cutout portion 156a having a substantially V-shape at a height lower than the above-described protrusions 152a, 152b, 152c and 152d is provided with the base 151. ) Is integrally formed with

And the width dimension of the notch 156a of this protrusion part 156 is narrower than the width dimension between the 1st cutting pieces 38. As shown in FIG.

And the pin 157 is formed in the front-back position of the protrusion part 156 of the upper surface of the base 151. As shown in FIG.

Next, a method of assembling the mirror 40 of the optical pickup 10 according to the present invention to the first cut piece 38 of the carriage 12 will be described.

First, the mirror 40 is placed on the cutout portion 156a of the protrusion 156 of the jig in an inclined state, and the carriage 12 is placed upside down, thereby placing the first side wall portion of the carriage 12 ( The notched groove 28 of 26 is fitted to the shaft rod 155 of the jig. Then, the pin 157 is inserted through the pin support hole (not shown) of the bottom plate portion 24 of the carriage 12 and supported on the base 151 of the jig so that the carriage 12 is not moved.

At this time, the mirror 40 has a surface portion 40b of the mirror 40 than the inclined surface 38a of the first cut piece 38 in the space between the side wall faces 38b of the first cut piece 38. Is located in a slightly protruding state (FIG. 2).

Subsequently, in FIG. 2, the gap between the side wall 38b of the first cut piece 38 and the side wall 40a of the mirror 40 (gap width H2 in FIG. 3) behind the carriage 12. Is 0.1 mm or less.) The UV-curable adhesive 13 is injected and filled to irradiate ultraviolet rays to fix it in a floating state as shown in FIG. 5.

Here, the mirror 40 is placed on the cutout of the projection 156 (Fig. 8 (b)), which is the attachment reference plane, by the jig, so that the mirror 40 is fixed to the upright piece 38, so that the mirror can be attached and fixed with high precision.

In addition, a space is formed in the first cut-out piece 38 of the carriage 12 by cutting it up, and since this space becomes an injection port for filling and applying the adhesive 13, it is easy from the rear of the carriage 12. Since it can bond, workability can be improved.

Moreover, the adhesive agent 13 mentioned above is attached to the inclined surface 38a of the 1st cutting piece 38 shown in FIG. 2 by attaching the mirror 40 in the state which the surface part 40b protruded from this inclined surface 38a. ) Can be formed into a structure that does not push out to the surface portion 40b of the mirror 40.

Subsequently, the lens actuator 110 of FIG. 1 is directly at the opening 36 (FIG. 2) in the bottom plate portion 24 of the carriage 12 so that the objective lens 14 is located at the center of the outgoing light from the mirror 40. Disposed over.

Next, based on FIG. 2, the method of assembling the light transmission part 18 of the optical pickup 10 which concerns on this invention to the 2nd cutting piece 31 of the carriage 12 is demonstrated.

First, the light receiving part 18 is integrally assembled to the holder 20.

And fixing the holder 20 which provided the light receiving part 18 in the space (cutout part 39) enclosed by the 2nd cutting pieces 31 and 31 of the carriage 12, and the support part 42. In order to do this, first, a jig is used to arrange the transmissive light portion 18 in a state with a predetermined gap therebetween.

At this time, as shown in FIG. 3, the said jig is used, and the window part 33a (FIG. 6) of the light transmission part 18 and the round hole 72 of the support part 42 oppose and arrange | position slightly.

Moreover, the upper surface of the end surface 31a of the 2nd cutting piece 31, the jaw part 4a of the holder 20, and the stem part 23a of the light receiving part 18 fixed to this jaw part 4a is fixed. It is slightly spaced apart and arranged.

Subsequently, the laser light emitted from the light transmitting part 18 shown in FIG. 1 is separately provided to the hole 46 of the holder 20 so that the laser light is emitted to the center of the objective lens 14 of the lens holder 112 through the mirror 40. The jig of 2 is inserted and the attachment position of the light receiving part 18 is adjusted to the center of this hole 46.

Thereafter, the gap dimension H1 is formed between the end face 31a of the second cut piece 31 described above and the upper face of the jaw portion 4a of the holder 20 and the stem portion 23a of the light transmitting portion 18. Is fixed to 200 µm or less by injecting and filling the ultraviolet curable adhesive 13 (S portion in FIG. 7).

The ultraviolet curable adhesive 13 is injected between the light transmitting surface 33 of the light transmitting portion 18 and the side wall surface of the supporting portion 42 so as not to block the window portion 33a and the round hole 72 that serve as the optical path of the laser beam. It is fixed by filling (T part in Fig. 7).

Thus, since at least 4 parts are affixed with the adhesive agent 13, the light transmission part 18 can be fixed to the carriage 12 reliably.

In the optical pickup 10 of the present invention, in which the assembly is completed, the laser light emitted from the light transmitting surface 33 of the light transmitting portion 18 passes through the round hole 72 of the supporting portion 42, and then the mirror ( It passes through 40 and is reflected at right angles to enter the objective lens 14 of FIG.

Then, the laser light emitted from the objective lens 14 is condensed on the optical disk surface, that is, reads the information recorded on the optical disk, and again passes through the same optical path the return light reflected from the optical disk surface corresponding to this information. It enters into the light receiving element in the light portion 18.

The information on the optical disc can be read by converting into a necessary electric signal in accordance with the light amount of the returned light.

In addition, following the information on the surface of the optical disc, the carriage 12 of the optical pickup 10 is controlled and moved along the shaft rod of the optical disc apparatus.

As described above, a carriage made of sheet metal, a bending piece that bends a portion of the carriage, and a predetermined gap is formed between the bending pieces to arrange a light receiving part, and the light transmitting part is formed by the bonding means. Since the light transmitting portion is fixed to the carriage in a floating state, it is possible to precisely adjust the positioning of the light transmitting portion without applying stress to the carriage when fixing for positioning.

The bending piece is composed of a pair of bending pieces arranged oppositely, and is formed by cutting and standing in opposite directions to each other, so that the bending pieces are easily deformed in the return direction. It is difficult to deform in the direction, so that it can be fixed securely and accurately.

Since the gap between the end face of the bent piece and the light transmitting portion is 200 µm or less, the amount of change in the linear expansion coefficient on the adhesion bonding surface can be reduced, and stable positioning accuracy can be maintained.

Then, a part of the carriage is raised in the opposite direction to form a bent piece, the jig is used to arrange a light transmitting part by forming a constant gap in the space of the bent piece, and the positioning of the light receiving part is adjusted, and the adhesion is also performed. By attaching and fixing the above-mentioned light transmitting part to the bent piece by means, it is possible to assemble with high precision even with a cheap carriage, thereby reducing the cost.

Claims (4)

A carriage made of sheet metal, a pair of bent pieces which are cut out in a direction opposite to each other, and arranged to face each other, and a light gap is formed by forming a predetermined gap between the bent pieces, and the light receiving part is disposed. The optical pickup, characterized in that the fixing means is attached to the bent piece through the adhesive means. delete The optical pickup according to claim 1, wherein a gap between a cross section of the bent piece and the light transmitting part is 200 m or less. A method of assembling a light transmitting part into a carriage made of sheet metal, wherein a part of the bottom plate of the carriage is bent in an opposite direction to form a bent piece, and a jig is used to form a bent piece in a space of the bent piece. And arranging a predetermined gap, adjusting the position of the light transmitting portion, and fixing and fixing the light transmitting portion to the bent piece using an adhesive means.