JP2000163756A - Optical pickup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently radiate the heat generated by a projection and photodetection member by fixing a holding part to a sticking means which has heat conductivity and radiating the heat from the projection and photodetection part through the holding part. SOLUTION: An optical integrated element 10 is clamped and fitted between contact parts 23f and 23g and the holding part 23 is arranged opposite while leaving a slight gap between an arm part 23b and the side wall surface 41b of a cut and raised piece 41. The heat generated by the optical integrated element 10 is radiated from its entire reverse surface and radiated directly to the holding part 23 from a vertical end surface through the contact parts 23f and 23g of the holding part 23. The arm part 23b is stuck on the opposite surface (side wall surface 41a of the 3rd cut and raised piece 41 of a carriage by using the sticking means such as solder and an adhesive having good heat conductivity and the heat from the small optical integrated element 10 as a heating source is conducted not only from the small-sized holding part 23, but also to the whole carriage by the sticking means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention 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 more particularly to a fixing structure of a light emitting / receiving member of the optical pickup.

[0002]

2. Description of the Related Art A conventional optical pickup includes a lens actuator having an objective lens housed in a carriage made of metal, a laser beam emitted from a mirror to the objective lens, and a return light from the objective lens. And a light projecting / receiving member for incidence.

As shown in FIG. 8, the carriage 51 has a box-like shape having a recess 54 formed by die-casting of aluminum or the like. The opening 52 is formed. The periphery of the opening 52 is a projection 53 having guides 53b on the left and right sides, and the surface of the projection 53 is formed with a pressed portion 53a that is processed with high precision.

As shown in FIG. 9, an optical integrated device (laser coupler) 10 serving as a light projecting / receiving member is provided with a ceramic main body 1.
0a, a concave portion 10c formed by depressing the center of the surface portion 10b of the main body 10a, and a laser beam (reflected light) which is disposed in the concave portion 10c, emits laser light to the outside, and returns from the outside. Light emitting and receiving element 10d for receiving
Window 10 made of transparent optical glass or resin to cover Oc
e. A plurality of cutouts 10f are formed in the vertical direction on the side surface of the main body 10a, and the cutouts 10f dissipate heat generated in the light emitting / receiving element 10d. A U-shaped second notch 10g, which is a positioning means, is formed on the side surface (end surface) in the left-right direction with high precision one by one, and serves as a reference when assembling. The surface portion 10b serves as an attachment reference surface when attaching to the carriage 51. A plurality of terminals (not shown) are provided on the back surface of the main body 10a so as to be electrically connected to the flexible substrate.

A method of incorporating the optical integrated device 10 into the carriage 51 in the optical pickup having the above-described configuration will be described with reference to FIG. First, after the mirror and the lens actuator are attached and fixed to a predetermined portion of the carriage 51, the optical integrated device 1 is inserted into the opening 52 of the carriage 51.
The optical integrated device 10 is brought into contact with the pressing portion 53a by using the two guide portions 53b of the projecting portion 53 as a guide so that the zero window portion 10e is located. Next, with the optical integrated device 10 pressed against the pressing portion 53a of the projecting portion 53, the mounting position of the optical integrated device 10 is finely adjusted and positioned, and the surface portion 10b of the optical integrated device 10 and the pressing portion are pressed. An adhesive or the like is applied to and fixed to the gap portion in a state where it is in contact with 53a.

[0006] By mounting the optical pickup having the optical integrated device 10 constructed as described above and the optical integrated device 10 incorporated therein to the optical disk device, the laser beam emitted from the optical integrated device 10 is transmitted to the window 10 e of the optical integrated device 100 and the carriage. 51
Through the square opening 52 of the wall portion 51b, further through the mirror, and bends at right angles from horizontal to vertical,
The light enters the objective lens of the lens holder. Then, the laser light emitted from the objective lens is condensed on the optical disk surface and reads information recorded on the optical disk. Further, the return light reflected from the optical disk surface according to this information enters the optical integrated device 10 through the same optical path. Then, according to the amount of the returning light, the light is converted into a necessary electric signal, and the information on the optical disk can be read. Further, following the information on the optical disk surface, the carriage 51 of the optical pickup is movably supported by the optical disk device, and performs a controlled movement along a shaft rod of the device.

[0007]

By the way, when the optical integrated device 10 which requires positioning accuracy is mounted on the carriage 51 of the conventional optical pickup, the optical integrated device 10 is assembled on the basis of the pressing portion 53a of the carriage 51. The carriage 51 is made of aluminum die cast or zinc die cast which has high rigidity and can be machined with high accuracy.
The cost of die casting is high and the carriage 51
Since the pressing portion 53a is subjected to secondary processing and finished with high accuracy, this has caused an increase in cost.

When information is recorded on the optical disk surface using an optical pickup, the laser light output of the optical integrated device 10 needs to be increased to several mW, which is about ten times the normal value. It was not possible to sufficiently cool only by heat radiation by the cutout portion 10f provided on the side surface, and the oscillation of the laser beam might be unstable. Therefore, the optical integrated device 1
It was necessary to efficiently radiate the heat generated at zero.

The present invention solves the above-mentioned problems, and uses a low-cost carriage made of a sheet metal to accurately mount and fix a light emitting and receiving member and efficiently radiates heat generated in the light emitting and receiving member. The purpose is to provide an optical pickup.

[0010]

At least one of the above objects is attained.
As a first solution to solve the above problem, a heat transmitting and receiving member and a holding part having a heat dissipating property to which the light emitting and receiving member is attached and fixed are provided. The heat is emitted from the light emitting and receiving member through the holding portion while being fixed by fixing means having a property.

As a second solution, the holding portion is formed with an arm having both ends bent in the same direction, and the arm is made substantially parallel to a side wall surface of a bent piece provided on the carriage. It is attached to the bent piece at the position where it is arranged so as to face.

Further, as a third solution, the fixing means is soldering.

As a fourth solution, the holding portion and the light emitting / receiving member are provided with positioning means at opposing portions, and are positioned by being inserted into a jig with each positioning means as a guide. .

As a fifth solution, the holding portion is provided with a contact portion capable of contacting the light emitting / receiving member.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1 to 6, an optical pickup 1 according to one embodiment of the present invention has an objective lens 14 attached to a carriage 11 made of a metal sheet metal. A lens actuator 15, an integrated element 10 that emits laser light to the objective lens 14 through a mirror 60, and receives return light from the objective lens 14, and a holding unit 23 to which the integrated element 10 is attached. It is composed of

The carriage 11 has a rectangular bottom plate 1.
2 and side walls 13a and 13b that are opposed to each other along both longitudinal edges of the bottom plate 12. One end of the side wall 13a protrudes from the bottom plate 12 in the longitudinal direction, and an engagement hole 13c is formed at the tip. The second side walls 20a, 20b, which are erected in the same manner as the side walls 13a, 13b, are provided integrally with the bottom plate 12 with a certain space in the longitudinal direction of the side walls 13a, 13b. I have. Second side wall 2
Penetrated round holes 21 are formed in Oa and 20b, respectively, and the inner diameter of each round hole 21 is formed to a size that can be inserted by one shaft rod (not shown).

The bottom plate 12 has a first opening 36 formed substantially in the center and penetrating in a substantially rectangular shape, and a first opening 36.
And a second opening 37 which is formed adjacently to and penetrates in an H-shape, and a notch groove 40 which is formed in a substantially rectangular shape at an outer side edge. A pair of first cut-and-raised pieces 38 that are opposed to each other are formed on a part of the edge portion facing the first opening 36, and the opposed surface is a side wall surface 38b. On a part of the edge facing the second opening 37,
The pair of second raised portions 39 that are bent pieces are
3a and 13b are opposed to each other, and the facing surface is a side wall surface 39b. An adhesive is injected and filled between the side wall surfaces 39b of the second cut-and-raised pieces 39 so that a collimator lens described later is attached and fixed.

At a part of the edge facing the notch groove 40,
The pair of third cut-and-raised pieces 41 is formed by the side wall portions 13a, 13b
Are opposed to each other so as to be along the side wall surface 41.
a, the back surface is a side wall surface 41b. Also, the third
Each of the cut-and-raised pieces 41 has a round hole 43 formed therethrough. Accordingly, the first, second, and third cut-and-raised pieces 38, 39, and 41 are cut and raised in opposite directions from the bottom plate portion 12 by a bending jig (not shown), and are bent at substantially right angles. It is a thing. Further, on the remaining edge of the notch groove 40, a plate-shaped connecting portion 18 is formed in a state slightly raised in a direction orthogonal to the side wall surface 41b facing the third cut-and-raised piece 41. . A rectangular cut groove 18a is provided on the connecting portion 18.
Are formed obliquely.

The lens actuator 15 includes an actuator base 15a and the actuator base 15a.
Are supported via four wires 65, and the objective lens 14
And a yoke 16 integrated with the lens holder 15b.
The actuator base 15a is provided with the carriage 1
The lens holder 15b is mounted and fixed on the first opening 36 so that the lens holder 15b can be moved vertically and horizontally by four wires 65.

The mirror 60 is a rectangular plate formed by depositing a metal film on an optical glass or an optical resin member, and is incorporated between the side walls 38 b of the first cut and raised piece 38. The mirror 60 and the lens actuator 15 reflect the laser beam incident on the mirror 60 right above, and
Each is attached to the carriage 11 so as to be incident on the center of the objective lens 14 held by 5b.

The collimator lens 45 is made of glass or resin, and comprises an optical lens 46 for converting incident laser light into parallel light, and a cylindrical lens barrel 47 having a cylindrical shape. The optical lens 46 is firmly fitted to the lens. The collimator lens 45 is arranged between the side wall surfaces 39b of the second cut-and-raised piece 39 of the carriage 11, and is fixedly attached using an ultraviolet curing adhesive.

The optical integrated device 10, which is a light projecting / receiving member, includes a light emitting device such as a laser diode for generating laser light, a light receiving device for detecting laser light, and the like. The holding unit 23
A heat radiating plate made of metal such as aluminum or zinc, comprising a substantially rectangular base 23a and arms 23b provided by bending both ends of the base 23a at substantially right angles.
A cut groove 23d, which is a positioning means cut out in a substantially semicircular shape, is formed on an end surface (upper surface, lower surface in FIG. 1), and a round hole 23c is formed in the arm portion 23b. The optical integrated device 10 is attached on the base portion 23a of the holding portion 23, and is electrically connected to a part of a flexible substrate described later. Then, at a position where the round hole 23c of the holding portion 23 and the round hole 43 of the third cut-and-raised piece 41 are opposed to each other, it is mounted and fixed by using the solder 17 as a fixing means. In addition, as this fixing means, in addition to a metallic material such as the solder 17, an adhesive having good heat conductivity or the like may be attached and fixed. As shown in FIGS. 4 and 5, the flexible substrate 19 includes a plurality of band-shaped circuit patterns (not shown) and a flexible insulating sheet sandwiching the circuit patterns from both sides.
Furthermore, it has two holes 19a penetrating the circuit pattern and the insulating sheet, and one semicircular cutout 19b. Then, on the flexible substrate 19,
The electronic components are fixed by soldering.

The flat lens 25 is formed by depositing a metal film on an optical glass or an optical resin member, and corrects optical aberration of incident light. Then, the flat lens 25 is fitted into the cut groove 18a of the connecting portion 18, and the optical integrated element 10
The optical integrated device 10 and the collimator lens 45 are arranged obliquely with respect to the optical axis direction between the optical integrated device 10 and the collimator lens 45.

Next, assembling of each component will be described with reference to FIG.
It will be described based on. First, a jig (not shown) for incorporating each component into the carriage 11 is prepared. Here, the jig includes a base having a rectangular parallelepiped shape, a plurality of protrusions formed to project upward from the base, and a notch formed by forming one of these protrusions into a substantially V shape. Have. Then, in order to attach the collimating lens 45 to the carriage 11 on which the cut-and-raised pieces 38, 39 and 41 formed by pressing and bending into a predetermined shape are formed, the carriage 11
Place it on a jig with it turned upside down, and accurately position and fix it so that it does not move. At this time, a projection of a jig projecting upward from the base is located in each of the openings 36 and 37 of the carriage 11. Before mounting the carriage 11 on the inclined surface of the notch of the jig,
The mirror 60 is placed in advance along the inclined portion 38a of the first cut-and-raised piece 36.

Next, the collimator lens 45 is fitted into the second opening 37 of the carriage 11 from above (from the bottom plate 12 side) while being attached to the jig.
5 is sandwiched between the side walls 39b of the second cut-and-raised piece 39. An ultraviolet curable adhesive (not shown) is injected and filled around the contact portion between the side wall surface 39b of the second cut-and-raised piece 39 and the outer peripheral wall of the lens barrel 47 of the collimator lens 45. Ultraviolet rays are applied to the portion where the adhesive has been sufficiently applied to fix the collimator lens 45 to the second cut-and-raised piece 39 of the carriage 11. Similarly, the flat lens 25
In the case where the carriage 11 is mounted upside down on the jig, the flat lens 25 is fitted into the cut groove 18a of the connecting portion 18 from above, and the adhesive is attached in the same manner as when the above-described collimator lens 45 is incorporated. Fix with. In the mirror 60, the mirror 60 is mounted on the basis of the notch of the protrusion of the jig, the mirror 60 and the first cut-and-raised piece 38 are positioned, and the above-described collimator lens 45 is bonded. Attach and fix in the same way as above.

Next, as shown in FIG.
After returning to the original state from the upside down state, the lens actuator 15 is placed across the opening 36 of the carriage 11 so that the objective lens 14 is located directly above the mirror 60, and the positioning and adjustment are performed to adhere. Attach and fix with an agent.

Next, a method for incorporating the optical integrated device 10 into the carriage 11 will be described with reference to FIGS. First, a new jig provided with two round bars 100a is prepared. The holding portion 23 is arranged between the round bars 100a,
The holding portion 23 is held on the jig so that the cut grooves 23d of the holding portion 23 are fitted into the holding grooves 23a. Next, the holding unit 2
3 and a thin double-sided tape 160 on the base 23a (see FIG. 6).
Then, a part of the flexible substrate 19 is placed thereon, and the flexible substrate 19 is fixed to the holding portion 23 via the double-sided tape 160. At this time,
The flexible substrate 19 has a hole 19a formed in one round bar 100.
a, and the notch 19b is inserted with the other round bar 100a as a guide, and is accurately positioned. next,
On the flexible substrate 19, the integrated element 10 is inserted between the round bars 100a using the second cutouts 10g as guides. And the flexible substrate 1
9, the integrated element 10 is fixed with an adhesive, and the circuit pattern (not shown) of the flexible substrate 19 and the integrated element 10 are fixed.
And the terminals are fixed by soldering. In this way, the integrated element 10 and the holding section 23 are attached and fixed with the flexible substrate therebetween.

Next, as shown in FIG.
In order to mount and fix the optical integrated device 10 mounted and fixed to the holding portion 23 in a space (a cutout groove 40) surrounded by the third cut-and-raised pieces 41 and the connecting portion 18, the jig is used. The optical integrated device 1 is provided with a certain gap in this space.
Place 0 floating. At this time, the inner wall surface of the arm portion 23b of the holding portion 23 and the side wall surface 41a of the third cut-and-raised piece 41 are opposed to each other with a slight gap. Next, the mounting position of the holding section 23 is adjusted using a jig so that the laser light emitted from the optical integrated device 10 is emitted to the center of the objective lens 14c of the lens holder 15b. Then, the solder 17 as a fixing means is inserted into a gap between the side wall surface 41b of the third cut-and-raised piece 41 and the arm 23b of the holding portion 23.
Is attached and fixed. Hole 43 and arm 2 of side wall surface 41b
The solder 17 accumulates in the hole 23c of 3b and is attached and fixed with a predetermined strength. Next, with reference to the dotted line L shown in FIGS. 4 and 5, the flexible substrate 19 is bent by about 90 degrees, and the terminals (not shown) of the flexible substrate 19 and the electromagnetic drive mechanism are arranged along the bottom plate 12 of the carriage 11. On the bottom plate portion 12 by soldering. Thus, the holding unit 2
Since the positioning of the carriage 3 is adjusted in a state of being floated in the air, and the carriage 3 is fixed in the air with the solder 17, the carriage 11 can be mounted and fixed at an accurate position without applying force.

In the optical pickup 1 in which the integration is completed, the laser light emitted from the optical integrated device 10 is connected to the connecting portion 18.
Is passed through a flat lens 25, further converted into parallel light by a collimator lens 45, passes through a mirror 60,
It is bent at a right angle and enters the objective lens 14. Then, the laser light emitted from the objective lens 14 is condensed on an optical disk surface (not shown) and reads information recorded on the optical disk. Further, the return light reflected from the optical disk surface according to this information enters the optical integrated device 10 through the same optical path. Then, according to the amount of the returning light, the light is converted into a necessary electric signal and the information on the optical disk is read. In addition, following the information on the optical disk surface, the carriage 11 of the optical pickup 1 is movably supported by the optical disk device, and performs a controlled movement along a shaft rod of the device.

In addition, the integrated device 10 performs a high output laser beam for writing information on the optical disk surface, and generates heat according to the output. This heat is radiated from the notch 10f of the optical integrated device 10, and
The holding portion 23 is radiated to the outside by conducting or radiating heat. Further, the carriage 1 is moved from the arm 23 b of the holding section 23.
1 through the solder 17 to be radiated.

Therefore, in the optical pickup 1 configured as described above, since the holding portion 23 can be assembled using the same sheet metal material as the carriage 11, the cost can be reduced by the material or the processing. In addition, in general, a cut groove 10g is formed in the optical integrated device 10 in advance, and this is used for positioning adjustment. Therefore, it is not necessary to perform additional processing, and the number of processing steps can be reduced.

Next, as a second embodiment, the holding unit 2
Modification 3 will be described with reference to FIG. In the first embodiment described above, the back surface of the optical integrated device 10 is
3 is mounted and fixed on the base 23a via the flexible substrate 19, whereas in the present embodiment, the holding portion 2
The contact portions 23f and 23g are provided on the upper edge and the lower edge of the base 23a.
Are set up at right angles, the back surface of the optical integrated device 10 is mounted and fixed on the base portion 23a of the holding portion 23 via the flexible substrate 19, and the vertical end surface of the optical integrated device 10 is contacted with the contact portion 23f, It is in direct contact with the inner wall of 23 g. Here, the contact portions 23f and 23g are bent pieces formed by bending the base 23a at substantially right angles. As described above, the optical integrated device 10 is sandwiched and fitted between the contact portions 23f and 23g, and the holding portion 23 provides a slight gap between the arm portion 23b and the side wall surface 41b of the third cut-and-raised piece 41. After being positioned and adjusted so as to be opposed to each other and being adjusted in position, it is fixed to the carriage 11 by fixing means such as soldering 17.

Accordingly, the heat generated in the optical integrated device 10 is radiated from the entire back surface of the optical integrated device 10 and is radiated directly from the vertical end surface to the holding portion 23 through the contact portions 23f and 23g of the holding portion 23. . The arm 23b
Is fixed to the opposing surface (side wall surface 41a) of the third cut-and-raised piece 41 of the carriage 11 by using a fixing means such as solder 17 or an adhesive having good thermal conductivity, so that a small optical integration which is a heat source is generated. Since the heat conduction from the element 10 is conducted not only from the small holding portion 23 but also to the entire carriage 11 by the fixing means and dissipated, the heat dissipating effect can be further enhanced.

[0034]

As described above, the optical pickup according to the present invention comprises a light emitting / receiving member and a heat-radiating holding member to which the light emitting / receiving member is attached and fixed, and the holding portion is mounted on a carriage made of sheet metal. By providing a gap and fixing with heat-conductive fixing means, and by releasing heat from the light emitting and receiving member via the holding portion, unnecessary external force is not applied to the carriage, and accurate positioning adjustment can be performed. It is possible to dissipate heat generated in the light emitting and receiving member via the holding portion. In addition, the light emitting and receiving member can be attached and fixed with high precision to the carriage by using a low-cost sheet metal.

Further, the holding portion has an arm portion having both ends bent in the same direction, and the arm portion is opposed to the side wall surface of the bent piece provided on the carriage so as to be substantially parallel to the side wall surface. As a result, the fixing space can be secured, the mounting and fixing can be performed smoothly, and the light emitting / receiving member separated from the arm can be mounted without affecting the heat.

Further, since the fixing means is formed by soldering, it can be firmly fixed after positioning, and the generated heat can be efficiently released to the outside via the solder.

The holding portion and the light emitting / receiving member are provided with positioning means at opposing portions, respectively, and are positioned by being inserted into the jig using the positioning means as a guide. It can be easily assembled.

Further, since the holding portion is provided with a contact portion capable of contacting the light emitting and receiving member, a large heat radiation area from the light emitting and receiving member, which is a heat source, can be secured, and the holding portion can be directly held from the contact portion. Since the heat can be dissipated to the entire part, the heat dissipating effect can be further enhanced, and the light emitting and receiving member can be used stably.

[Brief description of the drawings]

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

FIG. 2 is an enlarged perspective view of a main part of the optical pickup.

FIG. 3 is a perspective view for explaining assembly of each component of the optical pickup.

FIG. 4 is an exploded perspective view for explaining assembly of a light emitting / receiving member and the like of the optical pickup.

FIG. 5 is a perspective view showing a state where the light emitting and receiving members of the optical pickup are assembled.

FIG. 6 is an exploded perspective view for explaining the assembly of the carriage and the light emitting / receiving member of the optical pickup.

FIG. 7 is an enlarged perspective view of a main part of a second embodiment of the present invention.

FIG. 8 is an exploded perspective view for explaining assembly of a light emitting and receiving member of a conventional optical pickup.

FIG. 9 is a perspective view showing an optical integrated device.

[Explanation of symbols]

 Reference Signs List 10 Emitter / receiver member (optical integrated device) 10g Positioning means (second notch) 23 Holding part 23a Base 23b Arm part 23d Positioning means (cut groove) 23f, 23g Contact part 41 Third cut-and-raised piece (bent) Piece) 100a round bar

Claims (5)

[Claims] 1. A light emitting and receiving member and a holding part having a heat dissipating property to which the light emitting and receiving member is attached and fixed, and the holding part is fixed to a carriage made of sheet metal with a gap provided by a heat conductive fixing means. An optical pickup characterized in that heat generated from the light emitting / receiving member is released via the holding portion. 2. An arm portion having both ends bent in the same direction is formed on the holding portion, and the arm portion is arranged so as to be opposed to a side wall surface of a bent piece provided on the carriage so as to be substantially parallel to the side wall surface. 2. The bent piece is attached to the bent piece at a bent position.
Optical pickup as described. 3. The optical pickup according to claim 1, wherein said fixing means is soldering. 4. The holding unit and the light emitting / receiving member are each provided with a positioning means at a portion facing each other, and are positioned by being inserted into a jig by using the positioning means as a guide. 2. The optical pickup according to item 2. 5. The optical pickup according to claim 1, wherein the holding section is provided with a contact section capable of contacting the light emitting / receiving member.