JP2000228027A - Optical axis adjusting device for optical pickup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of work steps and to automate assembling by facilitating the optical axis adjustment of an optical pickup and improving assembling workability. SOLUTION: Rigid boards are used as an actuator wiring board 21 and a base wiring board 26, and the first connection terminal 23 of the actuator wiring board 21 and the second connection terminal 27 of the base wiring board 26 are not soldered before optical axis adjustment, and placed to closely face each other by keeping a moving space X necessary for adjustment. During optical axis adjustment, power to be supplied to a coil is directly supplied to the conductive terminal 24 of the actuator wiring board 21 from the outside, and after the optical axis adjustment is finished, by soldering the connection terminals 23 and 27 of both boards, the electrical conduction and mechanical fixing of both boards are carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical axis adjusting device for an optical pickup.

[0002]

2. Description of the Related Art FIG. 8 shows a first conventional optical axis adjusting device of an optical pickup. The objective lens 1 is fixed to a bobbin 2 and is elastically supported by four conductive springs 3. Coils 4a and 4b are wound around the bobbin 2, and constitute an electromagnetic driving circuit together with magnets 5a and 5b held on magnetic yokes 6 disposed on both sides of the bobbin. By applying a drive current to the tracking coil 4a and the tracking coil 4b, the objective lens can be driven in the focusing direction (Fo direction) and the tracking direction (Tr direction: a direction perpendicular to the paper surface). The other end of the spring 3
It is soldered to an actuator wiring board 9 fixed to the yoke 6. The above-described lens support system is called a four-wire system, and is the same as that disclosed in Japanese Patent Publication No. H03-21972 and Japanese Patent Publication No. H04-45894.

[0006] A rising mirror 13 is fixed to the bottom of the base 10, and a light emitting / receiving element 14 is provided on a side wall of the base 10. The light-emitting and light-receiving element includes a light-emitting element such as a semiconductor laser and a light-receiving element incorporated in one element. Each of them may have a separate structure, but for simplicity of description, the description will be made with a structure of a light emitting and receiving element.

[0004] Light rays emitted from the light emitting and receiving element 14 are reflected upward by the rising mirror 13 so that the objective lens 1
And irradiates a light spot on the disk 100. The reflected light from the disk 100 passes through the objective lens 1 again, is reflected in the horizontal direction by the rising mirror 13, returns to the light receiving element surface of the light emitting and receiving element 14, converts this into an electric signal, and Information can be read.

In an optical pick, a tangential tilt of an objective lens (TA in FIG.
Angle adjustment is performed for the N direction) and the radial tilt (the RAD direction in the figure). At the bottom of the base 10, there is a concave spherical sliding portion 10a, and at the bottom of the yoke a convex spherical sliding portion 6a.
, The tilt of the objective lens 1 can be changed around the center of the objective lens 1 as a center of rotation.

A female screw 6b is screwed on the bottom of the yoke 6, and a base 10 coaxially drilled below the female screw 6b.
Adjustment screw 11 is screwed into the female screw 6b. On the other hand, a leaf spring 12 is provided on the base 10,
One end of the yoke is pressed by the tip, and the adjusting screw 1
Along with 1, it acts in the direction of bringing the concave spherical sliding portion 10 a of the base 10 and the convex spherical sliding portion 6 a of the yoke 6 into close contact with each other while maintaining a balance around the center of the objective lens 1 as a center of rotation. ing. By rotating the adjustment screw 11 from the lower part of the base in this state, the objective lens 1 is
Can be fine-tuned.

If another adjusting screw 11 is arranged at a position (not shown) orthogonal to the plane perpendicular to the optical axis, the two adjusting screws 11 are appropriately rotated to allow the radial and tangential of the lens. Tilt adjustment in both directions is possible. The above prior art is generally used as a tilt adjustment mechanism for an optical pickup.
4-62133.

In the above-described optical axis adjusting device, after the optical axis adjustment, there is a danger that the tilt of the lens will be deviated due to external vibration or impact. Therefore, for example, the yoke 6 and the base 10
It is common to fill and solidify the adhesive 8 between them to reinforce them.

FIG. 9 shows an optical axis adjusting device of a second conventional optical pickup different from the first conventional example. The same reference numerals are given to the same parts as those in FIG. The objective lens 1 is fixed to a bobbin 2 and is elastically supported by four conductive springs 3. Coils 4a and 4b are wound around the bobbin 2, and constitute an electromagnetic driving circuit together with magnets 5a and 5b held on magnetic yokes 6 disposed on both sides of the bobbin. By applying a drive current to the tracking coil 4a and the tracking coil 4b, the objective lens can be driven in the focusing direction (Fo direction) and the tracking direction (Tr direction: a direction perpendicular to the paper surface). The other end of the spring 3 is soldered to an actuator wiring board 9 fixed to the yoke 6. The above-mentioned lens support system is called a four-wire system,
It is the same as that disclosed in JP-A-3-21972 and JP-B-04-45894.

A rising mirror 13 is fixed to the bottom of the base 10, and a light emitting and receiving element 14 is installed on a side wall of the base 10. The light-emitting and light-receiving element includes a light-emitting element such as a semiconductor laser and a light-receiving element incorporated in one element. Each of them may have a separate structure, but for simplicity of description, the description will be made with a structure of a light emitting and receiving element.

The light beam emitted from the light emitting and receiving element 14 is reflected upward by the rising mirror 13 and is reflected by the objective lens 1.
And irradiates a light spot on the disk 100. The reflected light from the disk 100 passes through the objective lens 1 again, is reflected in the horizontal direction by the rising mirror 13, returns to the light receiving element surface of the light emitting and receiving element 14, converts this into an electric signal, and Information can be read. The above is the same as in the first conventional example.

In the second conventional example, an actuator section is mechanically separated from the base 10, and a tangential tilt of an objective lens (T in FIG.
AN direction) and radial tilt (RAD direction in the figure)
Can be adjusted. Also, if necessary,
It is also possible to adjust the relative position of the objective lens with respect to the base 10 in the XYZ directions in the figure.

In the optical pickup having such a configuration, when adjusting the optical axis, the actuator section is held by an adjustment jig, and both tilts required for the adjustment and fine adjustment mechanisms in the XYZ directions are adjusted on the adjustment jig side. And can be fine-tuned.

In the above optical axis adjusting device, after adjusting the optical axis, for example, the adhesive 8 is filled between the yoke 6 and the base 10 and solidified to fix the relative positions of the base 10 and the lens. Then, the holding of both by the adjustment jig is released, and the adjustment of the pickup is completed. This method is called an air adjustment or an air tilt, and is an adjustment mechanism that is widely used in thin optical pickups. As in the first conventional example, a concave spherical tilt adjustment mechanism is provided on the bottom of the base 10. This is an effective method when the space cannot be mounted.

[0015]

However, the conventional configuration has the following problems to be solved. Since the optical axis of the pickup is adjusted so as to obtain the best signal while checking the level and balance of the reproduction signal, it is necessary to establish electrical continuity between the pickup and the adjustment jig during the adjustment. A light-emitting and light-receiving element is mounted on the base portion, and it is necessary to actually perform servo drive on one of the actuators. Therefore, it is necessary to make an electrical connection between the base and the actuator before the optical axis adjustment. Moreover,
The actuator and the base section need to use a flexible printed circuit board or the like as the actuator wiring board 9 so that the actuator wiring board 9 can follow the change in the relative position accompanying the adjustment. In addition, since it is necessary to electrically connect the actuator side and the base side, the mutual positions of the two are liable to fluctuate, the work is complicated, the automation of assembly is difficult, and the cost is increased. In the second prior art, in particular, in the stage before the adjustment, the mechanical connection between the base and the actuator is not performed, but both must be electrically connected by a flexible printed circuit board having low strength. And required careful handling.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide an optical axis adjusting device of an optical pickup which can improve workability of assembling the optical pickup, reduce man-hours, and automate assembly. With the goal.

[0017]

The following means are employed to solve the above two problems. The electric connection between the actuator and the base by the flexible printed circuit board is abolished, and rigid actuator wiring boards and base wiring boards are used, and each is firmly fixed to the actuator and the base. Before the adjustment, the solder connection portions of the two substrates are not soldered, and a space necessary for the adjustment is kept.

Prior to the optical axis adjustment, the step of electrically connecting the base and the actuator is eliminated. That is, the supply of the drive current to the actuator wiring board during the adjustment of the pickup is not directly performed through the base-side wiring board but is directly supplied to the actuator wiring board from the adjustment jig side.

After the adjustment of the mutual position between the actuator and the base is completed, the solder is bridged in the gap between the solder connection portions of the two substrates to establish electrical continuity and at the same time mechanically fix the relative positions of the two.

According to the present invention, the electrical connection by the flexible printed circuit board can be eliminated, so that the number of assembling steps of the optical pickup can be reduced and the assembling work can be easily automated.

Therefore, an optical axis adjusting device for an optical pickup according to a first aspect of the present invention comprises a light source, an objective lens for condensing light emitted from the light source on a recording medium, and an elastic support for the objective lens. An optical pickup comprising an actuator supported by a member and electromagnetically driven in a focus direction and a tracking direction, and a base for storing and holding the light source, the objective lens and the actuator, wherein the optical pickup is fixed to the actuator, and one end of the optical pickup is elastically supported. A first wiring member that is electrically connected to the coil via the member and has a first connection terminal at the other end; a first wiring member fixed to the base; one end connected to the drive body side; A second wiring member having a connection terminal, wherein the first wiring member is displaceable in accordance with optical axis adjustment of the pickup,
The first connection terminal and the second connection terminal are closely opposed to each other, and after adjusting the optical axis of the pickup, the first connection terminal and the second connection terminal are soldered. Fixing, electrically connecting the first wiring member and the second wiring member,
It is characterized by mechanical joining.

According to this configuration, the operation of electrically connecting the base of the optical pickup and the actuator section and the operation of mechanically fixing the optical pickup are performed at the same time, thereby reducing the number of assembly steps.

According to a second aspect of the present invention, in the optical axis adjusting device for an optical pickup according to the first aspect of the present invention, the first wiring member includes an electrical connection to the outside in addition to the first connection terminal. It has a conduction terminal, and supplies driving power to the actuator via the conduction terminal when adjusting the optical axis. Thereby, while giving the degree of freedom of the electrical connection to the actuator being adjusted, by separating the conductive terminal from the soldering portion, after the adjustment, the first connection terminal,
When the second connection terminal is solder-bridged, it has an effect of improving workability of soldering.

Further, according to a third aspect of the present invention, an optical axis adjusting device for an optical pickup according to the second aspect of the present invention,
The first wiring member has an electrically conductive terminal on an end side from the first connection terminal, and after the optical axis adjustment, cuts off the conductive terminal from the first wiring member. is there. This provides an effect of providing a degree of freedom of electrical connection to the actuator being adjusted, and enabling a reduction in the size of the pickup after adjustment.

[0025]

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

(Embodiment 1) FIG. 1 is a sectional view of an optical pickup according to Embodiment 1 of the present invention, FIG. 2 is a rear view of the optical pickup, and FIG. 3 is an actuator wiring board from the direction of arrow A in FIG. FIG.

First, the configuration on the actuator side will be described. The objective lens 1 is fixed to a bobbin 2 and is elastically supported by four conductive springs 3. Coils 4a and 4b are wound around the bobbin 2, and constitute an electromagnetic driving circuit together with magnets 5a and 5b held on magnetic yokes 6 disposed on both sides of the bobbin. By applying a drive current to the tracking coil 4a and the tracking coil 4b, the objective lens can be driven in the focusing direction (Fo direction) and the tracking direction (Tr direction: a direction perpendicular to the paper surface). The other end of the spring 3 is soldered to a rigid actuator wiring board 21, and the actuator wiring board 21 as a first wiring member is fixed to the yoke 6.

Next, the configuration of the base will be described. A rising mirror 13 is fixed to the bottom of the base 10, and a light emitting and receiving element 14 is installed on a side wall of the base 10. The light beam emitted from the light emitting and receiving element 14 is reflected upward by the rising mirror 13, condensed by the objective lens 1, and irradiates a light spot on the disk 100. The reflected light from the disk 100 passes through the objective lens 1 again, is reflected in the horizontal direction by the rising mirror 13, and
Then, the light returns to the light receiving element surface of No. 4 and is converted into an electric signal so that the information on the disk can be read.

Next, the connection between the actuator section and the base section will be described. The actuator wiring board 21 is made of a rigid glass epoxy board, for example, and is firmly fixed to the yoke 6. On the other hand, the base-side wiring board 26 as the second wiring member is also made of a rigid, for example, glass epoxy board, and is firmly fixed to the base 10.

As shown in FIG. 3, the actuator wiring board 21 has a soldering portion 22 of the conductive spring 3 at one end.
a, 22b, 22c, and 22d, (first) connection terminals 23a, 23b, 23c, and 23d at the other end (23 when formed as a whole, formed on the back surface), and further, at the tip end, with the outside. Terminals 24a, 24b, 24 for establishing electrical conduction between
c and 24d (24 when shown as a whole) are formed, and they are connected by a conductive pattern and a through hole, respectively.

On the other hand, as shown in FIG. 2, the base-side wiring board 26 has a flexible arm portion 26a extending toward the drive body, and the terminal portion of the light emitting / receiving element 14 and the actuator wiring board. 21 connection terminals 23a, 23b,
(Second) connection terminals 27a, 27b, 27c, 27d (27 when shown as a whole) are formed to be connected to 23c, 23d, respectively, and these terminals are connected to a connector connection portion (not shown) at the tip of the arm 26a. Are connected by a conductive pattern.

FIG. 1 shows a state before the optical axis adjustment of the optical pickup is performed. Connection terminal 23 of actuator wiring board 21 and connection terminal 27 of base-side wiring board 26
Does not perform soldering at the soldering portion H, and makes the optical pickups face each other with a gap X necessary for movement when adjusting the position and angle of the optical pickup.

When adjusting the optical pickup, the contact pin 200 of the adjustment jig is connected to the conductive terminal 2 of the actuator wiring board 21.
4 and the drive current to the actuator is supplied directly from the adjustment jig side. The current supply to the base such as a laser is supplied from the adjustment jig via the arm 26a of the base-side wiring board as in the related art.

After the adjustment of the optical pickup is completed, the solder is bridged and bonded to the gap X between the soldering portions H of the two substrates, and the electrical connection between the actuator wiring substrate 21 and the base-side wiring substrate 26 is established. Is fixed mechanically. Thereafter, the optical pickup is removed from the adjustment jig, and the conductive terminal portion is cut off from the actuator wiring board 21 along the cutout 25 of the actuator wiring board 21.

(Embodiment 2) Next, Embodiment 2 of the present invention will be described with reference to FIG. 4 and FIG. FIG. 4 is a sectional view of the optical pickup, and FIG. 5 is a rear view of the optical pickup. Since the configuration has many parts similar to those of the first embodiment, differences will be described.

The four conductive springs 3 are insert-molded together with the resin support block 30 and both are fixed. One end of the spring 3 elastically supports the bobbin 2. Further, the spring 3 is bent downward at a right angle inside the support block 30, and the other end is an extension 3 a that is exposed longer downward than the bottom surface of the support block 30.

The actuator wiring board 31 is made of a rigid, for example, glass epoxy board, and
It is firmly fixed to zero. On the other hand, the base-side wiring board 26
Similarly, is made of a rigid glass epoxy substrate, for example, and is firmly fixed to the base 10.

The spring 3 penetrates the hole of the actuator wiring board 31 and protrudes downward.
One of the lands 32a, 32b, 32c, 32d is soldered. Connection terminal 2 of base-side wiring board 26
The connection terminals 33a, 33b, 33c, 33d connected to 7a, 27b, 27c, 27d, respectively,
2a, 32b, 32c, 32d and four conductive springs 3 are connected by conductive patterns, respectively.

On the other hand, as shown in FIG. 5, the base-side wiring board 26 has a flexible arm portion 26a extending toward the drive main body, and the terminal portion of the light emitting / receiving element 14 and the connection terminal 27 are provided. And a connector connecting portion (not shown) at the tip of the arm portion are connected by a conductive pattern.

FIG. 4 shows a state before the optical axis adjustment of the optical pickup is performed. The soldering portion H is not soldered, and the actuator wiring board 31 and the base-side wiring board 2 are not soldered.
6 is opposed to the soldering portion H with a gap X required for movement at the time of position and angle adjustment.

When adjusting the optical pickup, the contact pin 200 of the adjusting jig is brought into contact with the extension 3a of the conductive spring 3,
The drive current to the actuator is supplied directly from the adjustment jig side. The current supply to the base, such as a laser, is supplied from the arm 26a of the base-side wiring board 26 from the adjustment jig as before.

After the adjustment of the optical pickup is completed, the solder is bridged in the gap between the soldering portions H of the two substrates, so that the actuator wiring substrate 31 and the base-side wiring substrate 26 are electrically connected and mechanically fixed. Thereafter, the optical pickup is removed from the adjustment jig, and the extension 3a of the conductive spring 3 is removed.
From the vicinity of the actuator wiring board 31.

(Embodiment 3) FIG. 6 is a sectional view of an optical pickup according to Embodiment 3 of the present invention, and FIG. 7 is a rear view of the optical pickup. The optical axis adjusting device of the optical pickup according to the third embodiment is substantially the same as that of the first embodiment. The actuator has a convex spherical sliding portion 6a at the bottom of the yoke 6 and a concave spherical shape at the bottom of the base 10. The difference is that the sliding portion 10a slides.

The actuator has a convex spherical sliding portion 6a at the bottom of the yoke 6 and a concave spherical sliding portion 1 at the bottom of the base 10.
0a is connected to the base 10 by the adjustment screw 11 and the holding spring 12 while being in contact with the base 10. By rotating the adjustment screw 11 to change the radial (Rad direction) tilt and the tangential (Tan direction) tilt, the optical axis of the objective lens 1 is optimally adjusted by the relative angle between the base 10 and the actuator. This tilt mechanism is disclosed in Japanese Patent Publication No. 04-62133.
This is the same as that disclosed in Japanese Patent Application Publication No.

Next, the connection between the actuator section and the base section will be described. The actuator wiring board 21 is made of a rigid glass epoxy board, for example, and is firmly fixed to the yoke 6. On the other hand, the base-side wiring board 26 is also made of a rigid glass epoxy board, for example, and is firmly fixed to the base 10.

The connection terminals 23a, 23b, 23c and 23d of the actuator wiring board 21 are connected to four conductive springs 3 by a conductive pattern, respectively, as shown in FIG. In addition, the conduction terminal 24 with the outside
Is also connected.

On the other hand, as shown in FIG. 7, the base-side wiring board 26 has a flexible arm 26a extending toward the drive main body, and the terminal of the light emitting / receiving element 14 and the actuator wiring board. Connection terminals 23a, 23b, 23
c, 23d, connection terminals 27a, 27b, 27
c, 27d, and these terminal portions are connected to a connector connection portion (not shown) at the tip of the arm portion by a conductive pattern.

FIG. 6 shows a state before the optical axis adjustment of the optical pickup is performed. The soldering portion H is not soldered, and the actuator wiring board 21 and the base-side wiring board 2 are not soldered.
6 is opposed to the soldering portion H with a gap X necessary for movement at the time of position and angle adjustment.

When adjusting the optical pickup, the contact pins 200 of the adjustment jig are connected to the conductive terminals 2 of the actuator wiring board 21.
4 and the drive current to the actuator is supplied directly from the adjustment jig side. In addition, current supply to the base side such as a laser is performed by using an adjustment jig as in the related art using an arm 2 of the base side wiring board.
6a.

After the adjustment of the optical pickup is completed, the solder is bridged and joined to the gap between the soldering portions H of the two substrates, so that the electrical connection between the actuator wiring board 21 and the base-side wiring board 26 is established and the mechanical wiring is performed. Perform fixing. After soldering, the optical pickup is removed from the adjustment jig, and the conductive terminal portion is cut off from the pick body along the cutout portion 25 of the actuator wiring board 21.

[0051]

As described above, according to the present invention, since the flexible printed circuit board is not used for the electrical connection between the actuator and the base, the flexible printed circuit board is destroyed, and the flexible printed circuit board is warped or deformed. This eliminates the risk of holding mistakes and makes it easy to automate the work.

Further, the electrical connection between the actuator and the base is established by soldering, and at the same time, by mechanically fixing the actuator, the number of assembling steps of the optical pickup can be reduced.

Further, the conductive terminal portion is extended on the actuator wiring board, and the optical axis is adjusted while supplying drive power from the adjustment jig to the actuator via the conductive terminal portion. Since it is possible to cut off from the substrate, it is possible to sufficiently secure the area of the conductive terminal portion that is extended and connected, and it is possible to improve the reliability of conduction when supplying driving power directly from the adjustment jig to the actuator. In addition, the size of the pickup can be reduced.

The wiring on the actuator side is usually four terminals for focus and tracking. However, it is not necessary to apply the present invention to all of the terminals. Even when the present invention is applied to some of the terminals, It can be easily inferred that the same effect can be obtained.

Although the wiring on the actuator side is usually four terminals in total for focus and tracking, the same effect can be obtained when the present invention is applied to other terminals (for example, terminals of sensors and ground terminals). Can easily be inferred.

Further, in the embodiment of the present invention, the light emitting and receiving elements are used for simplification of the description, but the effect of the present invention does not change even if the light emitting and receiving separate optical structures are used.

[Brief description of the drawings]

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

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

FIG. 3 is a circuit pattern diagram of the actuator wiring board viewed from the direction of arrow A in FIG. 1;

FIG. 4 is a sectional view of an optical pickup according to a second embodiment of the present invention.

FIG. 5 is a rear view of the optical pickup according to the second embodiment of the present invention.

FIG. 6 is a sectional view of an optical pickup according to a third embodiment of the present invention.

FIG. 7 is a rear view of the optical pickup according to the third embodiment of the present invention.

FIG. 8 is a cross-sectional view of a first conventional optical pickup.

FIG. 9 is a sectional view of a second conventional optical pickup.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Objective lens 2 Bobbin 3 Spring 4a, 4b Coil 5a, 5b Magnet 6 Yoke 8 Adhesive 10 Base 11 Adjustment screw 12 Pressing spring 13 Start-up mirror 14 Light emitting / receiving element 21, 31 Actuator wiring board 23, 33 Connection terminal 24 Conductive terminal 25 Notch 26 Base side wiring board 27 Connection terminal 30 Support block 100 Recording medium 200 Contact pin of adjustment jig

Claims (3)

[Claims] A light source; an objective lens for condensing light emitted from the light source onto a recording medium; an actuator supporting the objective lens by an elastic support member and electromagnetically driving the objective lens in a focus direction and a tracking direction; light source,
An optical pickup comprising an objective lens and a base for storing and holding an actuator, wherein the optical pickup is fixed to the actuator, one end of the optical pickup is electrically connected to the coil via the elastic support member, and the other end has a first connection terminal. A first wiring member having, fixed to the base,
A second wiring member having one end connected to the drive body and the other end having a second connection terminal, wherein the first wiring member is displaceable in accordance with the optical axis adjustment of the pickup; The first connection terminal and the second connection terminal are closely opposed to each other, and after adjusting the optical axis of the pickup, the first connection terminal and the second connection terminal are soldered. Fixed, said first
An optical axis adjusting device for an optical pickup, wherein the wiring member is electrically and mechanically joined to the second wiring member. 2. The first wiring member has an electric conduction terminal with the outside in addition to the first connection terminal, and supplies driving power to the actuator via the conduction terminal when adjusting the optical axis. 2. The optical axis adjusting device for an optical pickup according to claim 1, wherein: 3. The first wiring member has an electrically conductive terminal on the end side from the first connection terminal, and after the optical axis adjustment, cuts off the conductive terminal from the first wiring member. 3. An optical axis adjusting device for an optical pickup according to claim 2, wherein: