JPH09231582A - Optical pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To relax the mounting accuracy for a semiconductor laser element on a substrate and to facilitate the manufacturing of a device by flexibly displacing the position of a substrate part, mounting an optical part, between the position on which a light emitting element is arranged and the position on which an objective lens is arranged. SOLUTION: In this optical pickup device, a substrate 36 is flexibly displaced in the direction of a principal plane part (vertical direction) at a flexibly displacing part 52 located between the position on which a semiconductor laser element (laser coupler) is arranged and the position on which an objective lens driving mechanism 6 is arranged. In the optical pickup device, the inclination of the laser coupler 3 to the objective lens driving mechanism 6 is adjustable by means of the flexible displacement of such a substrate part 36.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technical field of an optical pickup device for recording / reproducing information signals on / from an optical recording medium such as an optical disk.

[0002]

2. Description of the Related Art Conventionally, an optical recording medium such as an optical disc has been proposed, and an optical pickup device for reading an information signal from the optical disc has been proposed.

This optical pickup device is composed of a light source such as a semiconductor laser element and a plurality of optical components for guiding a light beam emitted from the light source. The light beam emitted from this light source is focused on the signal recording layer of the optical disc by the objective lens.

Then, the light beam condensed on the signal recording layer is reflected by the signal recording layer and returns to the objective lens. The light beam returning to the objective lens is split by the beam splitter from the optical path returning to the light source, and is received by a photodetector such as a photodiode. The photodetection output output from the photodetector becomes a read signal of the information signal recorded on the optical disc.

In an optical disk reproducing apparatus having such an optical pickup device, the optical disk is rotated while being held at its central portion,
The optical pickup device is supported with the objective lens facing the main surface of the optical disc. By moving the optical pickup device over the inner and outer circumferences of the optical disc, the information signal can be read over the entire surface of the signal recording layer of the optical disc.

As such an optical pickup device,
The semiconductor laser device, the photodetector, the beam splitter, and the objective lens driving mechanism are arranged on one substrate portion, and these elements and optical components are covered by a cover member (shell cover) attached to the substrate portion. It has been proposed that it is configured.

In this optical pickup device, the light flux emitted from the semiconductor laser element is incident on the objective lens supported by the objective lens driving mechanism via the beam splitter, and the signal recording layer of the optical disc is recorded. Focused on top. Then, this light flux is reflected by the signal recording layer and is received by the photodetector via the objective lens and the beam splitter.

The objective lens drive mechanism is a mechanism for supporting the objective lens and moving the objective lens in the optical axis direction of the objective lens and in the direction orthogonal to the optical axis direction. The objective lens driving mechanism moves the objective lens in accordance with a read signal of an information signal recorded on the optical disc to cause the objective lens to follow eccentricity and so-called surface wobbling caused by rotation of the optical disc. It is moved so that the focal point of the light flux formed by the objective lens is always formed on the recording track on the surface of the signal recording layer of the optical disc.

In such an optical pickup device, the objective lens drive mechanism needs to be accurately positioned and mounted on the substrate portion with the position of the semiconductor laser element as a reference.

In such an optical pickup device, the cover member is provided with a supported portion which is supported in the optical disk reproducing device. Therefore, the cover member needs to be accurately positioned and attached to the substrate portion. Further, the cover member needs to be attached so that it does not move with respect to the substrate portion due to vibration or impact transmitted from the outside, that is, in a so-called play-free state with respect to the substrate portion.

[0011]

By the way, in the above optical pickup device, when the semiconductor laser element is mounted on the substrate portion, an error in mounting the cover portion on the substrate portion is taken into consideration. , It is necessary to make accurate positioning.

For example, in the semiconductor laser device, the allowable value of the amount of floating with respect to the substrate portion needs to be within 0.01 mm (10 μm) with respect to a predetermined position. This accuracy is obtained when the semiconductor laser device is attached to the substrate portion by adhesion.
This is close to the limit of the mounting accuracy, and when it is mass-produced, there are many cases that deviate from this allowable value.

When the semiconductor laser element is bonded to the substrate portion by a positional displacement exceeding the allowable value, the substrate portion and the semiconductor laser element have no room for reuse and are discarded. It is supposed to be.

Therefore, the present invention is proposed in view of the above-mentioned circumstances, and is an optical pickup device constituted by mounting a semiconductor laser element on a substrate portion, and the semiconductor laser element for the substrate is provided. It is intended to solve the problem of providing an optical pickup device in which the mounting accuracy is eased, manufacturing is facilitated, and the substrate portion and the semiconductor laser element can be effectively used. .

[0015]

In order to solve the above-mentioned problems, an optical pickup device according to the present invention comprises a substrate portion,
An optical part configured to have a light emitting element fixedly arranged on the substrate part and an objective lens for condensing a light beam emitted from the light emitting element on an optical recording medium, and an optical part arranged on the substrate part. And an objective lens drive mechanism that supports the objective lens so that the objective lens can be moved and operated, and the substrate portion includes a position where the light emitting element is disposed and a position where the objective lens drive mechanism is disposed. Bending displacement can be performed in the bending displacement portion located between them, and the inclination of the light emitting element with respect to the objective lens driving mechanism can be adjusted by this bending displacement.

Further, according to the present invention, in the above optical pickup device, the substrate portion is positioned and held with reference to a portion on the side on which the objective lens driving device is arranged with respect to the bending displacement portion. It is a thing.

Further, according to the present invention, in the above optical pickup device, the substrate portion is made of iron.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

The optical pickup device according to the present invention, as shown in FIG. 1, is an optical disc 101 which is an optical recording medium.
A light flux is condensed and irradiated on the surface of the signal recording layer 102, and the light flux is reflected on the light flux to cause the optical disc 10 to
1 is a device for reading the information signal recorded in 1.

In the optical disc reproducing apparatus having the optical pickup device, the optical disc 1 is used.
01 is rotated while holding the central part,
The optical pickup device is supported in a state in which the objective lens 20 for condensing the light flux is opposed to the main surface portion of the optical disc 101. The optical pickup device can be moved over the inner and outer circumferences of the optical disc 101 to read the information signal over the entire surface of the signal recording layer of the optical disc 101.

In this optical pickup device, a semiconductor laser element, a photodetector, a beam splitter, and an objective lens driving mechanism 6 for supporting the objective lens 20 are arranged on one substrate portion 2, 36, and these elements are arranged. And the optical component is covered with a shell cover 30 which is a cover member attached to the substrate portions 2 and 36.

The board parts 2 and 36 are composed of a base board 2 which is a first board part, and a printed board 36 which is a second board part attached to an upper surface part of the base board 2. .

The base substrate 2 is formed of an iron plate. The printed circuit board 36 includes a base material portion made of various insulating materials, a printed wiring pattern made of a copper foil having a predetermined shape on the main surface portion of the base material portion, and the wiring pattern. And a resist film covering the same.

As shown in FIGS. 2 to 5, the printed circuit board 36 is formed on the upper surface of the base substrate 2 with a part of the upper surface of the base substrate 2 exposed to the upper side. Is installed along with. This base substrate 2
The exposed portion of the upper side of the is the reference surface 44.

The printed circuit board 36 has a flange portion 50 protruding outward from the edge of the upper surface of the base substrate 2. As shown in FIGS. 2 and 3, the brim portion 50 has a defect portion 3 provided on the base substrate 2.
The printed circuit board 36 is formed by covering the upper part of the printed circuit board 8, 39.

The reference surface 44 and the collar portion 50 may be provided adjacent to each other, as shown in FIG. 5 (note that the numbers in parentheses in FIG. 5 are examples of dimensions). The unit is mm).

An optical section is arranged on the printed circuit board 36. The optical section is a semiconductor laser element 10 serving as a light emitting element, which is fixedly provided on the printed circuit board 36, and first and second photodetectors (photodiodes) 14a and 14b serving as light receiving elements. A laser beam emitted from the semiconductor laser device 10 is transferred to the optical disc 101.
And the objective lens 20 which is an optical component for condensing light on the surface of the signal recording layer 102.

As shown in FIG. 9, the semiconductor laser chip 10 and the photodetectors 14a and 14b are arranged on the same semiconductor base material portion 13, so that the laser coupler (L / C) 3 is formed. Are configured. That is, the semiconductor laser element 10 is disposed on the semiconductor base material portion 13 via the heat sink 11. In addition, the first
The second photodetectors 14a and 14b are formed on the semiconductor base member 13 in a state of being divided into a plurality of light receiving surfaces, respectively.

Then, in this laser coupler 3,
A beam splitter prism 12 is provided on each of the photodetectors 14a and 14b. The beam splitter prism 12 has a beam splitter surface 12R, which is an inclined surface portion having a predetermined inclination angle with respect to an upper surface portion of the semiconductor base material portion 13, directed toward the semiconductor laser element 10 side.

The laser coupler 3 is fixed on the printed circuit board 36 by gluing with the upper surface of the semiconductor substrate 13 parallel to the upper surface of the printed circuit board 36.

In this laser coupler 3, the semiconductor laser element 10 emits a laser beam toward the beam splitter surface 12R. The laser light flux emitted from the semiconductor laser device 10 is the beam splitter surface 1 described above.
The light is reflected by 2R and is emitted vertically above the semiconductor base portion 13.

The laser beam emitted from the laser coupler 3 is reflected by the reflection mirror 4 provided on the printed board 36 so as to cover the upper side of the laser coupler 3, and the laser beam of the printed board 36 is reflected. It is deflected in a direction parallel to the upper surface portion. Then, the laser light flux is reflected by the reflection prism 5 disposed below the objective lens 20 on the printed circuit board 36, and is deflected to the upper side perpendicular to the upper surface portion of the printed circuit board 36. The objective lens 20 is supported above the printed circuit board 36 by an objective lens driving mechanism 6 which will be described later and is spaced apart from the printed circuit board 36.

The laser light flux incident on the objective lens 20 via the reflection prism 5 is condensed by the objective lens 20 on the surface portion of the signal recording layer 102 of the optical disc 101.

The laser light flux focused on the surface of the signal recording layer 102 is reflected by the signal recording layer 102 and returns to the objective lens 20. The reflected light flux returning to the objective lens 20 is passed through the reflection prism 5 and the reflection mirror 4 and the beam splitter surface 12
Return to R.

The reflected light flux returning to the beam splitter surface 12R is split from the optical path returning to the semiconductor laser element 10 by passing through the beam splitter surface 12R and entering the beam splitter prism 12. The light is received by the first photodetector 14a. Further, this reflected light flux is reflected by the surface portion of the first photodetector 14a and the inner surface portion of the beam splitter prism 12, and is also received by the second photodetector 14b.

A read signal (RF signal) of an information signal recorded on the optical disc 101 based on the photodetection outputs output from the photodetectors 14a and 14b, and the focal point of the light flux by the objective lens 20. And a focus error signal (FE signal) indicating a deviation (focus error) between the surface of the signal recording layer 102 and the surface portion, and
A tracking error signal (TE signal) indicating the optical axis between the converging point and the recording track formed on the surface of the signal recording layer 102 and the deviation (tracking error) in the direction orthogonal to the recording track is calculated. .

That is, the read signal (RF signal)
Is obtained as the sum of the photodetection outputs of the photodetectors 14a and 14b. In addition, the focus error signal (F
E signal) is obtained as a difference between the photodetection outputs of the photodetectors 14a and 14b.

Further, the tracking error signal (T
E signal) is the photodetection output (A) from the light receiving surface on one side of the first photodetector 14a and the second photodetector 14
a, the sum of the photodetection outputs (D) from the light-receiving surface on the other side, and the photodetection output (B) from the light-receiving surface on the other side of the first photodetector 14a and the second photodetection. Difference ((A + D)-(B) with the sum of the photodetection output (C) from the light receiving surface on one side of the container 14a.
+ C)).

In each of the photodetectors 14a and 14b, the dividing line between the light receiving surface on one side and the light receiving surface on the other side is
As shown in FIG. 10, an angle of 45 ° is formed with respect to the tangential direction T of the recording track on the optical disc 101. The recording track is formed on the surface of the signal recording layer 102 on the optical disc 101.
Is formed in a spiral shape having a substantially concentric circle shape centered on the central part of the.

The objective lens driving mechanism 6 is arranged on the printed circuit board 36. As shown in FIG. 21, the objective lens driving mechanism 6 is configured to have a lens bobbin 21 that movably supports the objective lens 20 and a magnetic circuit unit that moves and operates the lens bobbin 21. .

The objective lens drive mechanism 6 supports the objective lens 20 and also supports the objective lens 20.
This is a mechanism for moving the objective lens 20 in the optical axis direction and in a direction orthogonal to the optical axis direction.

The objective lens driving mechanism 6 operates the objective lens 20 according to the focus error signal and the tracking error signal to move the objective lens 20 so that the objective lens 20 is eccentric with the rotation of the optical disc 101 or so-called surface wobbling. And is moved so that the focal point of the light flux formed by the objective lens 101 is always formed on the recording track.

The objective lens drive mechanism 6 is moved and adjusted on the printed circuit board 36, and then the printed circuit board 3 is adjusted.
The adjustment plate 54 is fixed to the unit 6 and is configured. A support block 6e is fixedly disposed on the adjustment plate 54. This support block 6e
Supports the lens bobbin 21 via four leaf springs 22, 23, 24, 25. The objective lens 20 is attached to the lens bobbin 21. The lens bobbin 21 includes the leaf springs 22, 23, 2
Due to the elastic displacement of 4, 25, it is movable in two axial directions, that is, vertical and horizontal directions.

A coil bobbin 26 constituting the magnetic circuit section is attached to the lens bobbin 21. This coil bobbin 26 has a focus coil 26
A is wound around the outer peripheral surface portion, and a pair of tracking coils 26b wound in a substantially annular shape are attached.

On the printed circuit board 36, there is arranged a movable yoke 60 which is moved and adjusted in conjunction with the adjusting plate 54. This movable yoke 60 is shown in FIG.
As shown in FIGS. 1 to 23, a pair of engaging protrusions (doughs) 63, 64 which are to be coupled are provided, and these engaging protrusions 63, 64 are provided on the arm portion 56 on the front end side of the adjusting plate 54. , 58 are fitted in and engaged with the holes 59 and the elongated holes 57, the movement of the adjustment plate 54 is adjusted. The movable yoke 60 is moved and adjusted in a two-dimensional direction along the upper surface portion of the printed circuit board 60.

The movable yoke 60 has a pair of yokes 27a and 27b protruding upward. A magnet 28 is attached to one of the yokes 27a and 27b. These magnets 28 and each yoke 27
The a and 27b form a magnetic circuit via the movable yoke 60. In this magnetic circuit, a magnetic gap portion is formed between the magnet 28 and the other yoke 27a.

The coil bobbin 26 is attached to the lens bobbin 21 to position a part of the focus coil 26a and a part of each tracking coil 26b within the magnetic gap of the magnetic circuit.

That is, when the focus coil 26a is supplied with a drive current corresponding to the focus error signal, the focus coil 26a receives an electromagnetic force due to the magnetic flux in the magnetic gap portion, and the lens bobbin 21 is moved to the focus coil 26a. The objective lens 20 is moved in the optical axis direction (vertical direction). In addition, the tracking coil 26
By supplying a drive current corresponding to the tracking error signal to b, the tracking coil 26b
Receives an electromagnetic force due to the magnetic flux in the magnetic gap,
The lens bobbin 21 is moved in a direction (left-right direction) orthogonal to the optical axis of the objective lens 20.

In this optical pickup device, the shell cover 30 is attached to the substrate portions 2 and 36.

As shown in FIGS. 6 to 8, the shell cover 30 has a shape capable of covering the optical portion by being mounted on the substrate portions 2 and 36.
It is made of a material having high dimensional accuracy and rigidity, such as PS resin or zinc die casting, by means such as injection molding.

The shell cover 30 includes the substrate portion 2,
A plurality of contact rods 43, 43, which are first contact portions protruding downward, are provided on the lower surface portion facing 36. Further, the shell cover 30 has a pair of contact claws 42, 42, which are second contact parts, on the side portion. These abutting claws 42, 42 correspond to the shell cover 30.
Support rods 41, 4 projecting downward from the lower surface of the
It is provided at the lower end side of 1 so as to project laterally.

As shown in FIG. 8, the lower end portions of the contact rods 43, 43 and the upper surface portions of the contact claws 42, 42 are located on the same plane P with each other.

When the shell cover 30 is attached to the base plates 2 and 36, the contact rods 43 and 43 are attached.
As shown in FIGS. 2 and 3, the lower end portion of the reference surface 4 is an exposed portion of the upper surface of the base substrate 2 to the upper side.
4 abuts. Further, when the shell cover 30 is attached to the board portions 2 and 36, the contact claws 42,
As shown in FIGS. 2 and 3, the upper surface of 42 is in contact with the lower surface of the collar portion 50 of the printed circuit board 36.

Since the lower surface of the printed circuit board 36 is along the upper surface of the base substrate 2, the lower surface of the printed circuit board 36 and the upper surface of the base substrate 2 are located on the same plane. Since the lower end portions of the contact rods 43, 43 and the upper surface portions of the contact claws 42, 42 are located on the same plane, the lower end portions of the contact rods 43, 43 are The abutting claws 42, 4 abutted on the reference surface 44
When the upper surface of the shell cover 30 is brought into contact with the lower surface of the collar portion 50, the shell cover 30 moves to the base plate portions 2, 36.
On the other hand, the positioning is accurately performed in the up-down direction (that is, in the contacting / separating direction with respect to the substrate portions 2 and 36).

As shown in FIG. 2, the shell cover 30 is formed so that the screws 37 inserted from the lower side into the screw insertion holes 40 formed in the substrate portions 2 and 36 are directed downward. It is attached to the board portions 2 and 36 by being screwed into the screw holes.

The shell cover 30 has a through hole 31 on the upper surface for exposing the objective lens 20 to the upper side.

When the shell cover 30 is formed by molding using a molding die, by forming the plane P as a plane located on the parting line (die-cutting portion), the shell cover 30 can be formed by the above-mentioned steps. It is possible to form the lower ends of the contact rods 43, 43 and the upper surfaces of the contact claws 42, 42 on exactly the same plane.

As a structure for attaching the cover member to the base plate portion which is a flat member, as shown in FIG. 27, the contact rod 143 and the hooking claw 141 are integrally formed on the side edge portion of the cover member 130. It is conceivable that the lower end portion of the corresponding rod 143 is brought into contact with the side edge portion of the upper surface portion of the substrate portion 112 while the hook claw 141 is hooked on the side edge portion of the substrate portion 112. Above hook 1
On the lower end side of 41, the claw portion 14 faces toward the contact rod 143.
2 is projected.

With this structure, the cover member 13
When 0 is attached to the substrate portion 112, the hooking claw 141 is elastically deformed outside the outer peripheral edge of the substrate portion 112 when the cover member 130 is attached to the substrate portion 112. Therefore, in this case, the cover member 130 needs to be formed of a material having elasticity such that the hooking claw 141 can be elastically deformed.

A material having such elasticity, for example, A
Synthetic resin materials such as BS resin are not suitable as materials for forming the cover member on which the supported portion is provided, because the dimensional accuracy is low and the temperature that causes thermal deformation is low.

Since the cover member is formed of PPS resin or zinc die-casting, which has high dimensional accuracy but does not have elasticity, it cannot be attached to the substrate portion due to the above-described structure of providing the hooking claw.

Further, the cover member 13 is attached to the substrate portion 112.
28, a pair of upper and lower support pieces 144 and 145 are provided at the side edge portions of the cover member 130 and the vicinity of the side edge portions of the base plate portion 112 is provided as shown in FIG. It is conceivable that it is sandwiched between 144 and 145.

In such a structure, the substrate portion 1
Depending on the accuracy of the thickness of 12 and the accuracy of the position and thickness of each of the support pieces 144 and 145, the space between the substrate portion 112 and each of the support pieces 144 and 145 is press-fitted or loosely fitted. This is either (backlash) and is unsuitable as a configuration for attaching the shell cover 30 to the board portions 2 and 36.

The shell cover 30 has an engaging groove 32 which is a supported portion at one side portion. The engagement groove 32 is formed as a portion between the coupling pieces 33, 34 by a pair of coupling pieces 33, 34 protruding from one side portion of the shell cover 30 toward the lateral side. ing. A thrust sleeve portion 35, which is a supported portion, is formed on the other side portion of the shell cover 30. The thrust sleeve portion 35 is formed as a linear cylindrical through hole.

In the above-mentioned optical disk reproducing apparatus, FIG.
As shown in FIG. 3, the support shaft 104 of the optical disk reproducing device is inserted into the thrust sleeve portion 35, and the supporting piece 103 of the optical disk reproducing device is fitted into the engaging groove 32 to engage with the optical pickup device. Is
It is supported in place.

The printed circuit board 36 is shown in FIG.
As shown in FIGS. 18 and 19, it has a short land portion 46 protruding outward from the side edge portion of the base substrate 2. On the short land portion 46, one short land 47 continuous with the printed wiring pattern to which the power supply terminal (+ terminal) of the semiconductor laser element 10 is connected, and in proximity to the one short land 47,
The ground terminal of the semiconductor laser device 10 (ground (GN
D) The other short land 48 continuous to the printed wiring pattern to which the terminal) is connected is formed.

The respective short lands 47 and 48 are short-circuited (short-circuited) with each other by soldering or the like during transportation and transportation of the optical pickup device alone. That is, in this state, the semiconductor laser device 1 is
The power supply terminal of 0 and the ground terminal are in a short-circuited state, and electrostatic breakdown of the semiconductor laser element 10 is prevented.

When the optical pickup device is used, that is, when the optical pickup device is incorporated in the optical disc reproducing device, as shown in FIG.
The short circuit between the power supply terminal and the ground terminal of the semiconductor laser element 10 can be released by folding the semiconductor laser element 10 along the side edge thereof.

The printed circuit board 36 is preferably a glass-epoxy printed circuit board, and has a thickness of about 0.2 mm, considering the ease of breaking the short land portion 46.

On the printed circuit board 36, as shown in FIG.
0 and FIG. 17, each of the above signals (RF signal, F signal
A connector 53 is provided for taking out (E signal, TE signal), supplying power to the semiconductor laser element 10, and supplying a drive current to the objective lens drive mechanism.

Then, in this optical pickup device, as shown in FIGS. 10 and 11, the substrate portions 2 and 36 are located at the positions where the semiconductor laser device 10 is disposed (that is, the laser coupler 3 is attached thereto). Position)
In the bending displacement portion (base substrate bending position) 52 located between and the position where the objective lens driving mechanism 6 is disposed, the bending displacement in the main surface portion direction (vertical direction) is possible.

In this optical pickup device, the tilt displacement of the laser coupler 3 with respect to the objective lens drive mechanism 6 can be adjusted by such bending displacement of the substrate portions 2 and 36.

That is, assuming that the distance L between the bending displacement portion 52 and the side edge portion on the side where the laser coupler 3 is attached is 10 mm to 11 mm as shown in FIG. 10, as shown in FIG. , The bending displacement portion 52 by moving the side edge portion upward or downward by 0.1 mm.
It is found that when the laser is bent, the tilt of the laser coupler 3 can be adjusted over ± 0.52 ° from sin ⁻¹ (0.1 / 11) = 0.52 °. At this time, the direction in which the board portions 2 and 36 are bent depends on the polarity (+ side, − side) of the EF balance (the direction in which the neutral point of the focus error signal deviates from the best state of jitter in the read signal).
Side).

In the optical disc reproducing apparatus, the substrate portions 2 and 36 are positioned and held with reference to the portion on the side where the objective lens driving device 6 is arranged with respect to the bending displacement portion 52. That is, the board portions 2 and 36 are positioned with respect to the shell cover 30 in a portion on the side where the objective lens driving device 6 is arranged with respect to the bending displacement portion 52. Therefore, the adjustment by bending the substrate portions 2 and 36 is performed by the laser coupler 3 with respect to the reference plane of the optical disk reproducing device.
Is tilted.

The base substrate 2 is preferably formed of an iron plate. Aluminum (AL) may be broken by bending, and zinc (Zn) may be bent to cause creep.
Also, even if bent with stainless steel (Sus), it will return due to spring back and high-precision adjustment cannot be performed.

An example of component accuracy and mounting accuracy in this optical pickup device will be given below with reference to FIGS. 13 to 16.

In this optical pickup device, the position of the principal ray emitted from the objective lens 20 is targeted within ± 0.3 mm with reference to the position of the shell cover 30. Further, in this optical pickup device, the fall of the chief ray is caused by the shell cover 3
The target is within ± 0.5 ° with reference to the position of 0.

The positional deviation between the board portions 2 and 36 and the shell cover 30 is caused by the X-axis direction (the board portions 2 and 3).
6 within ± 0.05 mm with respect to the upper surface of 6 and the direction along the recording track) and the Y direction (direction along the upper surface of the substrate portions 2 and 36 and perpendicular to the recording track). Further, the displacement of the shell cover 30 in the height direction with respect to the substrate portions 2 and 36 is within ± 0.05 mm. Therefore, as shown in FIG. 13, the inclination error between the board portions 2 and 36 and the shell cover 30 is as follows.
In the X direction, sin ⁻¹ (0.05 / 22) = 0.13 ° In the Y direction, sin ⁻¹ (0.05 / 15) = 0.19 °. However, the distance between the reference surfaces 44 in the X direction is 22 mm, and the reference surface 44 in the Y direction is
This is when the distance between them is 15 mm.

The accuracy of the positional deviation of the reference hole, which serves as a reference for the position of the objective lens driving mechanism 6 on the substrate portions 2 and 36, is ± 0.05 m in both the X and Y directions.
It is within m. Further, the flatness of the upper surface portions of the substrate portions 2 and 36 is within ± 0.02 mm as shown in FIG. Assuming that the distance L between the optical axis of the objective lens 20 and the semiconductor laser device 10 (laser coupler 3) is 10 mm, the inclination of the portion to which the semiconductor laser device 10 is attached is sin ⁻¹ (0 .02 / 10) = 0.10 ° In the Y direction, sin ⁻¹ (0.02 / 10) = 0.10 °.

Next, considering the positional accuracy of the reflection mirror 4 and the reflection prism 5, the positional deviation with respect to the substrate portions 2 and 36 is ± 0.05 m in both the X and Y directions.
Within m, the error of span between them is ± 0.1
Within mm. As shown in FIG. 15, the accuracy of mounting the reflection mirror 4 on the substrate portions 2 and 36 is within ± 0.2 °, and the parallelism between the reflection mirror 4 and the reflection prism 5 is ± 0. It is within 1 °.

The positional deviation of the laser coupler 3 with respect to the substrate portions 2 and 36 is caused in both the X and Y directions.
Within ± 0.05 mm. In addition, the laser coupler 3
The float of the substrate parts 2 and 36 is within ± 0.01 mm as shown in FIG. Therefore, the inclination of the disc laser coupler 3 with respect to the substrate portions 2 and 36 is sin ⁻¹ (0.01 / 1.8) = 0.32 ° in the X direction and sin ⁻¹ (0.01 / 0.01 in the Y direction. 3.4) = 0.17 °. However, the laser coupler 3 in the X direction
Is 1.8 mm, and the length of the laser coupler 3 in the Y direction is 3.4 mm.

Here, when the tilt of the chief ray in the X direction is calculated, √ ((0.32) ² + (0.2) ² + (0.1) ² +
(0.1) ² + (0.13) ² ) = 0.42 ° When the tilt of the principal ray in the Y direction is calculated, √ ((0.17) ² + (0.2) ² + (0.1) ² +
(0.1) ² + (0.19) ² ) = 0.35 ° When the displacement of the principal ray in the X direction is calculated, √ ((0.05) ² + (0.05) ² + (0.1) ² +
(0.05) ² + (0.05) ² + (23 x sin 0.42
°) ² ) = 0.21 mm Next, when the displacement of the principal ray in the Y direction is calculated, √ ((0.05) ² + (0.05) ² + (0.05) ² +
(0.05) ² + (23 x sin 0.35 °) ² ) = 0.1
It will be 7 mm. As a result, the tilt of the chief ray in the X direction (0.42 °) approaches the target value of ± 0.5 °, and an increase in the defect rate for this item is expected.

In this optical pickup device, the tilt of the chief ray in the X direction can be corrected by adjusting the bending displacement of the substrate portions 2 and 36.
A reduction in defective rate can be realized.

Next, the procedure for assembling and adjusting the optical pickup device will be described.

In order to assemble this optical pickup device, first, the laser coupler 3 is fixed and disposed by adhesion at a predetermined position on the substrate portions 2 and 36.

Next, the lens bobbin 21 to which the objective lens 20 is attached is attached to the leaf springs 22, 23, 24, 2 described above.
Adjustment plate 5 supported so as to be movable via
4 is arranged on the substrate portions 2 and 36.

Then, the position of the lens bobbin 21 is set to a predetermined position with respect to the semiconductor laser element 10 by adjusting the position of the adjusting plate 54 with respect to the substrate portions 2 and 36.

For adjusting the position of the lens bobbin 21 to a predetermined position with respect to the semiconductor laser device 10, the information signal recorded on the optical disc 101 is read,
Level and jitter of the read signal (RF signal), E
F balance (amount of deviation between the neutral point of the focus error signal and the best state of jitter in the read signal)
This is done by finding the position where and are the best.

The position of the adjusting plate 54 is adjusted by moving and rotating (tilting) in the three-dimensional direction on the substrate portions 2 and 36.

With the position of the lens bobbin 21 at the predetermined position with respect to the semiconductor laser device 10, the adjusting plate 54 has its rear end portion 55 with respect to the printed circuit board 36, as shown in FIG. By being soldered with the solder 66, it is fixed to the substrate portions 2 and 36.

By adjusting the adjusting plate 54 as described above, the objective lens driving mechanism 6 causes the objective lens 2 to move.
It is adjusted to a state in which 0 is supported at the best position with reference to the position of the semiconductor laser device 10.

Then, the yokes 27a and 27b are positioned with reference to the position of the lens bobbin 21, that is, the position of the coil bobbin 26, and the substrate parts 2, 3
6 above.

As described above, the yokes 27a and 27b are connected to each other via the movable yoke 60 and arranged on the substrate portions 2 and 36, and are arranged along the upper surface portion of the substrate portions 2 and 36. It is designed to be movable in the dimension. Also,
The movable yoke 60 is an engaging projection (dough) that serves as a coupled portion for adjusting the position on the substrate portions 2 and 36.
It has 63 and 64, and is connected to the adjusting plate 54 through these engaging projections 63 and 64.

That is, each of the above-mentioned yokes 27a, 27b
Is moved on the substrate portions 2 and 36 following the two-dimensional component of the movement of the adjustment plate 54 on the substrate portions 2 and 36 along the upper surface portion of the substrate portions 2 and 36. Therefore, the positioning of the yokes 27a and 27b with reference to the position of the coil bobbin 26 is performed simultaneously with the movement adjustment of the adjustment plate 54.

The respective yokes 27a and 27b are
The position of the substrate portions 2 and 36 on the upper surface portion is fixed to the substrate portions 2 and 36 with the position of the lens bobbin 21 adjusted with the semiconductor laser device 10 as a reference. To be done. These yokes 27
The a and 27b are fixed to the board portions 2 and 36 by screwing the screws 65 and 65 inserted in the screw insertion holes 61 and 62 provided in the movable yoke 60 into the screw holes of the board portions 2 and 36. By doing.

By adjusting the adjusting plate 54 and the movable yoke 60 as described above, in the objective lens driving mechanism 6, the yokes 27a and 27b are arranged in the substrate portions 2 and 3 respectively.
It is adjusted in a state in which it is arranged perpendicular to 6 and a sufficient space between the yokes 27a and 27b and the coil bobbin 26 is secured.

Now, as shown in FIG. 24, each yoke 1
When 27a and 127b are fixedly attached to the substrate portion 112, the two-dimensional direction on the substrate portion 112 indicated by the arrow A and the arrow B in FIG. When the position of the coil bobbin 126 is adjusted in the tilting direction on the substrate 112, the yokes 127a, 12 are
The distance between 7b and the inner wall of the coil bobbin 126 becomes narrow. If the distance between each of the yokes 127a and 127b and the inner wall of the coil bobbin 126 becomes narrow, the movable range of the coil bobbin 126 with respect to the substrate portion 112 becomes narrow, which hinders the normal operation of the optical pickup device. There is a risk that

Further, as shown in FIG. 25, the adjusting plate 154 and the yokes 127a and 127b are integrated, and the yokes 127a and 127b are also synchronized with the position adjustment of the adjusting plate 154. When the coil bobbin 126 is moved upward, when the coil bobbin 126 is tilted and supported with respect to the adjustment plate 154 due to the twist of the leaf spring 124, the yoke 127a,
The distance between 127b and the inner wall of the coil bobbin 126 becomes narrower.

Further, when the coil bobbin 126 is tilted with respect to the base plate portion 112, as shown in FIG. 26, the movable stroke of the coil bobbin 126 toward the lower side, that is, the base plate portion 112 side is reduced. Resulting in. The stroke of the coil bobbin 126 that can be moved to the lower side depends on the substrate portion 11 of the coil bobbin 126.
This is because it is regulated by the contact with 2.

[0100]

As described above, in the optical pickup device according to the present invention, the substrate portion to which the optical portion having the light emitting element and the objective lens is attached has the position where the light emitting element is arranged and the objective lens. The bending displacement can be performed in the bending displacement portion located between the position where the light emitting element is disposed, and the inclination of the light emitting element with respect to the objective lens can be adjusted by the bending displacement.

That is, the present invention is an optical pickup device constructed by mounting a semiconductor laser element on a substrate portion, and the mounting accuracy of the semiconductor laser element on the substrate is relaxed, and the manufacturing is facilitated. Thus, it is possible to provide an optical pickup device capable of effectively utilizing the substrate portion and the semiconductor laser element.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a configuration of an optical pickup device according to the present invention.

FIG. 2 is an exploded perspective view showing a schematic configuration of the optical pickup device.

FIG. 3 is a longitudinal cross-sectional view of a main part showing a main part of the optical pickup device in a state where a shell cover is attached to a substrate part.

FIG. 4 is a plan view showing a configuration of a substrate portion of the optical pickup device.

FIG. 5 is a main part perspective view showing a main part of a state where the shell cover is attached to the substrate part in the optical pickup device.

FIG. 6 is a perspective view showing a configuration of a shell cover of the optical pickup device.

FIG. 7 is a plan view showing a configuration of a shell cover of the optical pickup device.

FIG. 8 is a vertical sectional view showing a configuration of a shell cover of the optical pickup device.

FIG. 9 is a perspective view showing a configuration of a laser coupler of the optical pickup device.

FIG. 10 is a plan view showing a positional relationship of optical components in the optical pickup device.

FIG. 11 is a vertical cross-sectional view showing a positional relationship of optical components in the optical pickup device.

FIG. 12 is a side view showing position adjustment of a laser coupler in the optical pickup device.

FIG. 13 is a plan view showing an error in the plane of the position of the shell cover with respect to the substrate portion in the optical pickup device.

FIG. 14 is a plan view showing an in-plane error of the position of the laser coupler with respect to the substrate portion in the optical pickup device.

FIG. 15 is a vertical cross-sectional view showing the positional accuracy of optical components in the optical pickup device.

FIG. 16 is a plan view showing an error due to the inclination of the position of the laser coupler with respect to the substrate portion in the optical pickup device.

FIG. 17 is a plan view showing the arrangement of optical components in the optical pickup device.

FIG. 18 is a plan view showing a shape of a substrate portion in the optical pickup device.

FIG. 19 is a side view showing the shape of a substrate portion in the optical pickup device.

FIG. 20 is a side view showing a state where the short land portion of the substrate portion of the optical pickup device is bent.

FIG. 21 is an exploded perspective view showing a configuration of an objective lens driving mechanism of the optical pickup device.

FIG. 22 is an exploded perspective view showing the configuration of an adjusting mechanism for adjusting the position of the coil bobbin in the objective lens driving mechanism of the optical pickup device.

FIG. 23 is a vertical cross-sectional view showing the configuration of an adjusting mechanism for adjusting the position of the coil bobbin in the objective lens driving mechanism of the optical pickup device.

FIG. 24 is a perspective view showing a broken configuration of an adjusting mechanism for adjusting the position of a coil bobbin in an objective lens driving mechanism of a conventional optical pickup device.

FIG. 25 is a vertical cross-sectional view showing the configuration of an adjusting mechanism for adjusting the position of the coil bobbin in the objective lens driving mechanism of the conventional optical pickup device.

FIG. 26 is a front view showing the configuration of an adjusting mechanism for adjusting the position of the coil bobbin in the objective lens driving mechanism of the conventional optical pickup device.

FIG. 27 is a vertical cross-sectional view of a main part showing a main part of a conventional optical pickup device in a state where a shell cover is attached to a substrate part.

FIG. 28 is a vertical cross-sectional view of a main part showing another example of the main part in a state where the shell cover is attached to the substrate part in the conventional optical pickup device.

[Explanation of symbols]

2 base substrate, 3 laser coupler (L / C), 4 reflection mirror, 5 reflection prism, 6 objective lens drive mechanism, 10 semiconductor laser device, 13 semiconductor substrate part, 1
4a 1st photodetector, 14b 2nd photodetector, 20
Objective lens, 21 lens bobbin, 26 coil bobbin, 27a, 27b yoke, 28 magnet, 30
Shell cover, 32 engagement groove, 35 thrust sleeve part, 36 printed circuit board, 42 contact claw, 43 contact rod, 44 reference surface, 46 short land part, 47 one short land, 48 one other short land, 5
0 collar part, 52 base board bending position, 54 adjustment plate, 60 movable yoke, 63, 64 engaging protrusion

Claims (3)

[Claims] 1. An optical system comprising a substrate portion, a light emitting element fixedly arranged on the substrate portion, and an objective lens for condensing a light beam emitted from the light emitting element onto an optical recording medium. And an objective lens driving mechanism which is disposed on the substrate portion and movably supports the objective lens. The substrate portion includes a position where the light emitting element is disposed and the objective lens. An optical pickup in which a bending displacement can be performed in a bending displacement portion located between the driving mechanism and a position, and the inclination of the light emitting element with respect to the objective lens driving mechanism can be adjusted by the bending displacement. apparatus. 2. The optical pickup device according to claim 1, wherein the substrate portion is positioned and held with reference to a portion on the side where the objective lens driving device is arranged, relative to the bending displacement portion. 3. The optical pickup device according to claim 1, wherein the substrate portion is made of iron.