JP2000339879A - Optical pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical pickup device which obviates an increase in a cost, has a good assembly characteristic and is not deteriorated in performance against impact during the transportation of an optical disk device even if a carriage composed of thin parts, such as a sheet metal carriage in particular, is used. SOLUTION: A main shaft 27 is inserted into round holes 21i and 21i and a first notched groove 21g is slidably supported by a sub-shaft 28, by which the carriage 21 is slidably supported. The front end of a second side wall part 21e is provided with a second notched groove 21h and a spacing is disposed between this second notched groove 21h and the sub-shaft 28. As a result, the carriage 21 is so regulated as not to be deformed more than this spacing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an optical pickup device used in an optical disk device for recording or reproducing information on or from an optical disk.

[0002]

2. Description of the Related Art An optical pickup device is mounted on an optical disk device, is supported movably in a radial direction of the optical disk, and makes a laser beam incident on an information recording surface of the optical disk.
The information is recorded on the information recording surface, and the recorded information is reproduced.

FIG. 11 shows a conventional optical pickup device 50.
A carriage 51 attached to an optical disk device (not shown), a biaxial actuator 52,
The carriage 51 includes a reflection mirror 53 that is adhered and fixed at approximately 45 degrees to the bottom plate 51 a of the carriage 51, a light emitting / receiving element 55 held by a holder 54, and a cover 56.

The biaxial actuator 52 includes a biaxial base 52a as a fixed portion, a lens holder 52c elastically supported on the biaxial base 52a via a suspension wire 52b, and a lens holder 52c.
, And is fixed to the carriage 51 by an adhesive S (see FIG. 12).

The lens holder 52c has a yoke 52e which forms a magnetic circuit together with a magnet (not shown).
Are formed integrally, and by energizing each coil of the coil bobbin 52f around which the focusing coil and the tracking coil are wound, the magnetic flux generated in each coil is
By interacting with the magnetic flux generated by the magnetic circuit, the lens holder 52c is driven in the focusing direction and the tracking direction.

On the other hand, the light emitting / receiving element 55 is mainly composed of a light emitting element for emitting laser light and a light receiving element for receiving laser light. The holder 54 holding the light emitting / receiving element 55 is attached and fixed to the carriage 51 by an adhesive T (see FIG. 12). A circuit board (not shown) to which electronic components are soldered is attached to the back of the light emitting / receiving element 55. A cover 56 that covers the circuit board is provided for protection of the circuit board and electromagnetic shielding. Is provided. Note that the circuit board constitutes a circuit for supplying an electric signal to the light emitting / receiving element 55 and for stably driving the light emitting element.

The laser light emitted from the light emitting element passes through the light emitting / receiving surface 55a of the light emitting / receiving element 55,
By about 90 degrees, and enters the objective lens 52d along the optical axis of the objective lens 52d. Then, a focusing operation is performed so that the laser beam narrowed down by the objective lens 52d is focused on the information recording surface of the optical disk, and a tracking operation is performed so as to follow the information recording track of the optical disk.

The return light reflected on the information recording surface of the optical disk again passes through the objective lens 52d,
In 3, the signal is bent by 90 degrees and is received by the light receiving element in the light emitting / receiving element 55, whereby a reproduction signal from the optical disk can be obtained.

The carriage 51 is made of sheet metal and has a substantially rectangular bottom plate portion 51a.
And a first side wall 51b and a second side wall 51c, which are respectively opposed to each other along both longitudinal edges. One end of the first side wall 51b is connected to the bottom plate 5
1a, and has a notch groove 51d at its tip.
Are formed.

Further, the first and second side wall portions 51b, 51
Similarly to c, third side wall portions 51e, 51e which are erected along the longitudinal direction are provided integrally with the bottom plate portion 51a. Further, round holes 51f, 51f are formed in the third side wall portions 51e, 51e, respectively.

On the other hand, in the optical disk device, a main shaft 57 and a sub-shaft 58 are held at predetermined intervals so as to be parallel to each other, and the main shaft 57 is inserted through round holes 51f, 51f formed in the carriage 51. ,
The sub-shaft 58 is slidably supported by the notch groove 51d, so that the optical pickup device 50 is slidably supported along each shaft.

[0012]

However, in the conventional optical pickup device 50 having such a configuration,
There were the following problems.

That is, although the low cost sheet metal is used for the carriage 51 of the conventional example, as shown in FIG. 12, the round holes 51f, 51f and the portions A and B where the main shaft 57 is engaged with the round holes 51f. The center of gravity of the optical pickup device 50 is located substantially at the center G 'of the substantially rectangular bottom plate portion 51a with respect to the center of gravity G of the triangle ABC formed by the notch groove 51d and the portion C with which the sub shaft 58 is engaged. So, for example,
When an impact is applied during transportation of the optical disk device, the impact acts on the center of gravity G ′, and a torque is generated due to a deviation from the center of gravity G of the triangle ABC, and the second side wall 51 of the carriage 51 is generated.
The c-side, particularly the end 51g, is greatly deformed, and as a result, the two-axis actuator 52, the reflection mirror 53, or the holder 54, which is bonded and fixed to the carriage 51, is peeled off and the strength is reduced, or their positions are shifted. ,
There is a problem in that the optical axis is shifted due to plastic deformation of the carriage 51 itself, making it impossible to perform recording / reproduction, and the performance of the optical pickup device 50 is deteriorated.

In order to prevent the above-described deformation, the end of the end 51g of the second side wall 51c of the carriage 51 is extended at the end thereof, and the same notch groove 51d formed at the end of the first side wall 51b is not shown. A notch groove 51d is formed, and part A,
A method of supporting the carriage 51 at four points together with the parts B and C is considered, but in this case, the main shaft 5
7 and the sub-shaft 58 are accurately kept parallel to each other,
If the respective positions of f, 51f and the two notched grooves 51d, 51d are not accurately formed, each shaft 57, 58
The smooth movement of the carriage 51 between them cannot be obtained, so that the optical disc apparatus itself must be designed with high accuracy, and there is a problem that the cost is greatly increased.

FIGS. 13A and 13B show Japanese Patent Application Laid-Open No. 58-115.
659 includes a rail 10
By moving four rotors 101 from the inside between 0 and 100 ', the movable table 102 as a carriage is
A method of supporting by points is shown. In this case, rail 1
The holders 103, 103 for rotatably supporting the rotors 101, 101 are fixed to the movable table 102 at predetermined intervals on the 00 side, and the rotor 101, 103 on the rail 100 'side.
Holders 103 ′ and 103 ′ that rotatably support 101 are
The rails 100, 100 'are elastically displaceable in a direction connecting the rails 100, 100' to the movable table 102 via leaf springs 104 at predetermined intervals.
Even if the parallelism between 0 'is slightly shifted, the shift is caused by the leaf spring 104.
The movable table 102 can be moved smoothly even with four-point support.
No additional parts other than the movable table 102, such as the holder 103, 103 ', and the holding shaft 105, are required, and the cost is increased and the assemblability is deteriorated.

Further, in the structure shown in FIG. 11, by adopting a thicker metal plate,
Although the strength of 1 is increased, the optical pickup device becomes heavy, and the access speed becomes slow because the moving acceleration becomes small when controlling the access to the information recording surface of the optical disk. Therefore, it is desirable to use a thin carriage. In addition, a larger press machine is required for sheet metal processing of a thicker carriage, so that the cost of the carriage increases due to the introduction of expensive equipment.

On the other hand, when the carriage is formed by aluminum die-casting or the like, the carriage is not plastically deformed by an impact having a predetermined strength by forming the carriage entirely or partially with a thick portion. Can be designed as follows. However, in recent years, small-sized optical disc devices such as portable types have been proposed, and optical pickup devices mounted thereon have been required to be further reduced in weight and thickness. Under such circumstances, the carriage has to be designed to have a thin portion. Therefore, even with a carriage formed by aluminum die-casting or the like, the same problem as the above-described sheet metal carriage has occurred.

For applications in which a small optical disk device is not required, the above-mentioned carriage, which is entirely or partially formed of a thick portion, is used. Even in this case, a particularly strong impact is applied. Finally, it should be added that when the optical disk device is placed under the expected conditions, the same problem as that of the carriage constituted by the thin portion occurs.

According to the present invention, in particular, even if a carriage composed of a thin portion such as a sheet metal carriage is used, the cost is not increased, the assemblability is good, and the optical disk apparatus is resistant to impact during transportation or the like. An object is to provide an optical pickup device whose performance does not deteriorate.

[0020]

Means for Solving the Problems As a first means for solving the above problems, one end of the carriage is
The first shaft is slidably supported in at least two places along the longitudinal direction of the first shaft, and the other end of the second shaft is substantially parallel to the first shaft. A supporting portion slidably supported, and a regulating portion provided along with the supporting portion in a longitudinal direction of the second shaft, and a predetermined gap is provided between the regulating portion and the second shaft. When the carriage is displaced, the displacement is regulated by the contact of the regulating portion with the second shaft.

Further, as a second solving means, a side wall portion is provided on the carriage in the longitudinal direction of the first and second shafts, and a through hole provided at one end of the both side wall portions. Wherein the first shaft is inserted through the first shaft, and the supporting portion and the regulating portion are provided at the other ends of the side wall portions, respectively.

Further, as a third solving means, the carriage is made of sheet metal, and the side walls are a pair of side walls formed by bending a part of the carriage.

Further, as a fourth solving means, the support portion and the restricting portion are notched grooves in which a part of the side wall portion is cut out.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical pickup device according to an embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a perspective view of an optical pickup device 20 according to a first embodiment of the present invention. The optical pickup device 20 includes a carriage 21 made of a sheet metal formed by press working, a biaxial actuator 22 having an objective lens 22 a attached and fixed to the carriage 21,
Laser light is emitted to the objective lens 22a through the collimator lens 23 and the reflection mirror 24, and the objective lens 22a
And a holder 26 for holding the light emitting / receiving element 25.

The carriage 21 has a substantially rectangular bottom plate portion 21c partially having a curved portion 21a and a protruding portion 21b.
A first side wall 21d and a second side wall 21e, which are opposed to each other along both longitudinal edges of the bottom plate 21c.
And a third side wall 21f erected from the protrusion 21b along the longitudinal direction of the bottom plate 21c. One end of each of the first and second side walls 21d and 21e protrudes from the bottom plate 21c, and has a front end provided with a first notch groove 21g as a support part and a second notch as a restriction part. A groove 21h is formed.

Further, an end of the first side wall 21d opposite to the end on which the first notch 21g is formed, and a third end.
Are formed in the side wall 21f.

Next, a substantially square opening 21j is formed substantially at the center of the bottom plate 21c.
A pair of projecting portions 21k, 21k are formed so as to be opposed to each other at an edge in the longitudinal direction with respect to the bottom plate portion 21c of j.
The opposing surfaces of the projecting portions 21k, 21k have side wall surfaces 211, 2
11 are provided.

On the other hand, a first bent piece 21m is provided upright adjacent to the curved portion 21a of the bottom plate portion 21c. A substantially triangular projection 21n is provided on the upper end of the first side wall 21d.
Is provided, and the protruding portion 21n is constituted by a second bent piece 21o and a support piece 21p. Further, the second bent piece 21o is arranged substantially symmetrically with respect to a longitudinal straight line passing through the center of the first bent piece 21m and the objective lens 22a.

The bottom plate 21c has a pair of third bent pieces 21 erected along the direction perpendicular to the longitudinal direction at the ends opposite to the round holes 21i in the longitudinal direction.
q and 21q are formed at predetermined intervals.

Next, the collimator lens 23 is a lens for making the emission angle of the laser light emitted from the light emitting / receiving element 25 substantially parallel, and is provided between the side walls 21l provided on the projecting portions 21k. Is fixed at a predetermined position using an adhesive. On the other hand, the reflection mirror 24
Is for reflecting the laser light transmitted through the collimator lens 23 from the light projecting / receiving element 25 and incident on the mirror surface 24a in the optical axis direction of the objective lens 22a. The reflection mirror 24 is attached at an angle of approximately 45 degrees to the bottom plate 21c, between the side walls 211, 211 of the protruding portions 21k, 21k, and fixed using an adhesive.

Next, the light emitting / receiving element 25 is composed of a main body 25a and a flange-shaped stem portion 25 integrally assembled with the main body 25a.
A light emitting element such as a laser diode and a light receiving element such as a photodiode (not shown) are mainly accommodated in the main body 25a. Further, a terminal 25c of the light emitting element and the light receiving element is provided at the rear of the stem 25b.
Are projecting outward (in FIG. 1, toward the front).

An optical element 25d for transmitting laser light emitted from the light emitting element and guiding return light from the optical disk to the light receiving element is fixed to the front surface of the main body 25a with an adhesive. The light emitting / receiving element 25 is pressed into a through hole having the same shape as that of the stem portion 25b provided in the holder 26 so that the holder 2
6 is held. Left and right ends 26a of the holder 26,
26a is a third bent piece 21 erected on the carriage 21.
A predetermined gap is provided on each of the opposing surfaces of q and 21q, and fixed by bonding or soldering.

Next, the biaxial actuator 22 includes a biaxial base 22b and a mounting portion 22 fixed to the biaxial base 22b.
c, one end of the four suspension wires 22d is fixed to the mounting portion 22c, the other end is fixed and held flexibly, and a lens holder 22e having an objective lens 22a, and a lens holder 22e And an integrated yoke 22f.

The biaxial base 22b is formed with a pair of mounting pieces 22g, 22g standing substantially symmetrically.
The biaxial actuator 22 is mounted on the carriage 21 such that the mounting pieces 22g, 22g face the first and second bent pieces 21m, 21o formed on the carriage 21 with predetermined gaps therebetween. Is fixed by an adhesive or soldering.

The optical pickup device 20 described above is
Third side wall 21f and first side wall 2 of carriage 21
1d, the first shaft, that is, the main shaft 27 is inserted through the round holes 21i, 21i formed respectively.
The first notch 21g provided on the side of the first side wall 21d opposite to the round hole 21i is slidably supported by the second shaft, that is, the sub-shaft 28. It is slidably supported.

Further, in the second notch groove 21h provided at the end of the second side wall 21e, the direction 2 in FIG.
As shown in FIG. 2 which is a partial side view as viewed from above, gaps d and d are provided between the sub shaft 28 and the upper end 29 and the lower end 30 of the second cutout groove 21h. . As a result, an impact is applied to the optical disk device, and FIG.
Even when the second side wall 21e is deformed upward 31 as shown in A or downward 32 as shown in B, the maximum displacement is d, and the carriage 21 is not plastically deformed. The two-axis actuator 22 adhered and fixed to the carriage 21, the holder 26 holding the light emitting / receiving element 25, and the reflecting mirror 24 are not peeled off or displaced. Does not deteriorate.

The second notch 21h is provided in the carriage 2
Since they can be formed simultaneously during one press working, the cost of parts does not increase. When assembling the optical disk device, even if the sub-shaft 28 is held by the optical disk device,
8 can support the first and second notched grooves 21g and 21h having an open shape at the end, so that assemblability is improved. In the embodiment of the present invention, the gap d is set to about 0.5 mm.
Although it is 2 mm, the present invention is not limited to this, and may be set within a range where the performance of the optical pickup device does not deteriorate.

In the embodiment of the present invention, the optical pickup device 20 is connected to the main shaft 27 so that the optical axis of the laser beam emitted from the objective lens 22a is substantially perpendicular to the information recording surface of the optical disk. By adjusting the angle or position of the sub-shaft 28, the radial direction (RAD) and the tangential direction (TA) shown in FIG.
N), the angle is adjusted (SKEW adjustment). Then, after the adjustment, as shown in FIG.
In some cases, the sub-shaft 28 may be inclined up to ± θ (≒ 0.5 degrees) in the vertical direction with respect to the bottom plate 21 c of the carriage 21 from the state where the sub-shaft 28 is parallel to the main shaft 27. The gap d is set so that the performance of the optical pickup device 20 is not deteriorated by an impact to the device.

FIG. 5 is a partial perspective view showing a second embodiment of the present invention, in which the second notch groove 21h in FIG. FIG. 6 shows FIG.
FIG. 9 is a partial side view as viewed from the direction 6 in the same manner as in the first embodiment. As in the first embodiment, a gap d is provided between the sub shaft 28 and the upper end 34 and the lower end 35 of the oval hole 33. d is provided. By doing so, the same effect as that of the first embodiment can be obtained, and further, the first embodiment can be obtained.
Since the tip of the second side wall surface 21e is not cut away as in the embodiment, even when a strong impact is applied, the tip has an effect of further improving the strength against plastic deformation. is there.

FIG. 7 is a partial perspective view showing a third embodiment of the present invention, in which the second notch 21h in FIG. 1 is replaced by a notch 36 with a bent piece. This is one in which bent pieces 37 and 38 are erected along the upper end 29 and the lower end 30 of the second notch groove 21h shown in FIG. 2 so as to be substantially 90 degrees with the second side wall surface 21e. is there. FIG.
FIG. 8 is a partial side view seen from a direction 8 in FIG.
As in the second embodiment, gaps d and d are provided between the sub shaft 28 and the upper end surface 39 and the lower end surface 40 of the cutout groove 36 with a bent piece. Also in this case, the same effects as those of the first embodiment can be obtained, and the upper end surface 39 and the lower end surface 40 that are the contact portions with the sub shaft 28 when an impact is applied are flat. First,
There is an effect that the surface of the sub-shaft 28 is less likely to be damaged as compared with the case where the sheet is received at the edge of the sheet metal as in the second embodiment.

FIG. 9 shows a fourth embodiment of the present invention, in which the first and second notched grooves 21g and 21h in FIG. 1 are eliminated, and the U-shaped guide member 41 is bent. Piece 4
FIG. 4 is a partial perspective view showing a state in which 1a and 41b are fixed to the carriage 21 so as to be integrated with first and second side walls 21d and 21e of the carriage 21, respectively. The guide member 41 is screwed to the carriage 21.
It is fixed by a method such as bonding or soldering. Further, a part of the carriage 21 may be formed in the shape of the guide member 41.

The bent pieces 4 above and below the guide member 41
The second ribs 45, which also have the function of the second notch groove 21h, are provided so that the first ribs 44, 44 having the function of the first notch groove 21g shown in FIG.
45 are formed to face each other.

FIG. 10 is a sectional view taken along the line 10-10 in FIG. 9, in which the sub shaft 28 is slidably supported. Further, similarly to the first to third embodiments, the gaps d and d are provided between the sub shaft 28 and the upper end surface 47 and the lower end surface 48 of the second ribs 45 and 45, respectively.
Is provided. Also in this case, the same effects as those of the first embodiment can be obtained, and the first ribs 44,
Can be formed on the same bent piece 42, 43, so that the center between the sliding surfaces 46, 46 of the first ribs 44, 44 and the upper end surface 47 of the second ribs 45, 45 are formed. There is an effect that the accuracy in alignment with the center between the and the lower end face 48 can be improved.

The first to fourth embodiments of the present invention have been described with reference to the case of a sheet metal carriage. However, the present invention is not limited to this. For example, a carriage formed by die casting such as aluminum die casting or molding may be used. In this case, the present invention can be applied.

In the optical pickup device 20 of the present invention, the laser light emitted from the light emitting element in the light emitting / receiving element 25 passes through the collimator lens 23 and further passes through the reflection mirror 2.
4 is reflected by the mirror surface 24a and bent at a right angle, and enters the objective lens 22a. The laser light emitted from the objective lens 22a is condensed on the information recording surface of the optical disk, and the return light reflected from the information recording surface in accordance with the information passes through the same optical path, and passes through the same optical path. The light is incident on the light receiving element in 25. Then, according to the amount of the returning light, it is converted into a necessary electric signal, and the information on the information recording surface of the optical disk can be read. In addition, following the information recording surface of the optical disk, the carriage 21 of the optical pickup device 20 moves the shafts 27 and 28 of the optical disk device.
Make a controlled movement along.

[0047]

As described above, according to the present invention,
One end of the carriage is slidably supported on the first shaft at at least two places along the length of the first shaft, and the other end of the carriage is substantially parallel to the first shaft. A supporting portion slidably supported by the arranged second shaft, and a regulating portion provided along with the supporting portion in a longitudinal direction of the second shaft, and the regulating portion, the second shaft, When the carriage is displaced, the displacement is regulated by contact of the regulating portion with the second shaft, so that the displacement is regulated.
Since the restricting portion restricts the deformation of the carriage beyond the predetermined gap in response to an impact during transportation to the optical disk device or the like, the performance of the optical pickup device can be prevented from deteriorating.

Further, side walls are provided on the carriage so as to face in the longitudinal direction of the first and second shafts, and the first shaft is inserted through through holes provided in the both side walls. By providing the supporting portion and the regulating portion at the other end of the optical pickup device, it is possible to prevent the performance of the optical pickup device from deteriorating due to an impact even if a carriage constituted by a thin portion is used.

Further, since the carriage is made of sheet metal and the side walls are a pair of side walls formed by bending a part of the carriage, the supporting portion and the regulating portion can be formed simultaneously with the processing of the carriage, so that the cost is increased. Without letting
It is possible to prevent the performance of the optical pickup device from deteriorating due to impact on the optical disk device.

Further, since the supporting portion and the regulating portion are cutout grooves in which a part of the side wall portion is cut out, the second shaft is held in the optical disk device at the time of assembling the optical disk device. Even so, the second shaft can support the cutout groove, so that the assemblability can be improved.

[Brief description of the drawings]

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

FIG. 2 is a partial side view of the optical pickup device according to the first embodiment of the present invention.

FIG. 3 is a partial side view for explaining a function of a second cutout groove in the optical pickup device according to the first embodiment of the present invention.

FIG. 4 is a partial cross-sectional view illustrating a function of a second cutout groove in the optical pickup device according to the first embodiment of the present invention.

FIG. 5 is a partial perspective view of an optical pickup device according to a second embodiment of the present invention.

FIG. 6 is a partial side view for explaining a function of an oval hole according to the optical pickup device of the second embodiment of the present invention.

FIG. 7 is a partial perspective view of an optical pickup device according to a third embodiment of the present invention.

FIG. 8 is a partial side view for explaining a function of a notched groove with a bent piece according to an optical pickup device of a third embodiment of the present invention.

FIG. 9 is a partial perspective view of an optical pickup device according to a fourth embodiment of the present invention.

FIG. 10 is a partial cross-sectional view illustrating a function of a guide member according to an optical pickup device according to a fourth embodiment of the present invention.

FIG. 11 is a perspective view of a conventional optical pickup device.

FIG. 12 is a plan view of a conventional optical pickup device.

13A and 13B are a plan view and a side view for explaining another example of a conventional pickup feed mechanism.

[Explanation of symbols]

 Reference Signs List 20 optical pickup device 21 carriage 21h second notch groove 22 biaxial actuator 22a objective lens 23 collimator lens 24 reflection mirror 25 light emitting / receiving element 26 holder 27 main shaft 28 sub shaft

Claims (4)

[Claims] An end of the carriage is slidably supported on the first shaft at at least two places along a length direction of the first shaft, and the other end is provided with the first shaft. A supporting portion slidably supported by a second shaft disposed substantially in parallel with the shaft, and a restricting portion provided along with the supporting portion in the longitudinal direction of the second shaft. An optical pickup, wherein a predetermined gap is provided between the optical pickup and the second shaft, and when the carriage is displaced, the displacement is regulated by abutting the restricting portion against the second shaft. apparatus. 2. A side wall portion is provided on the carriage in the longitudinal direction of the first and second shafts, and the first shaft is inserted into a through hole provided at one end of each of the side wall portions. 2. The optical pickup device according to claim 1, wherein the supporting portion and the regulating portion are provided at the other ends of the side wall portions, respectively. 3. 3. The optical pickup device according to claim 2, wherein the carriage is made of sheet metal, and the side wall portions are a pair of side wall portions obtained by bending a part of the carriage. 4. The optical pickup device according to claim 3, wherein said support portion and said regulating portion are cutout grooves formed by cutting out a part of said side wall portion.