JPH0721871B2 - Balanced movable device for optical pickup - Google Patents

Description

The present invention relates to an objective lens of an optical pickup for reading recorded information from an information recording medium such as an optical video disc or a compact disc by light, or a mirror used in an optical system. The present invention relates to a balanced movable device for an optical pickup that drives a prism or the like.

(Prior Art) A laser diode is built in an optical pickup, and its output laser light is focused on an information recording surface of a disc by an objective lens to form a spot light spot, and an information recording example (called a track) is irradiated. The information recording train is recorded on a medium that modulates transmitted or reflected light (hereinafter, referred to as reflected light),
When the reflected light is modulated in an analog manner by the information,
There are cases where digital modulation of 1 and 0 is performed, but digital formats such as compact discs (CD) are increasing.

In a CD, the depth is recorded in a 1/4 wavelength hole (pit), the reflection of the laser light from the bottom and the reflection from the periphery cancel each other out, and the light reflected from the pit becomes weak, and the mirror surface has no hole. The reflected light from is stronger. The width of this pit is about 0.5 microns, and the length increases or decreases by a certain unit depending on the information. In CD, the pits are spirally arranged in a row at intervals of about 1.6 microns. This 1.6 micron wide pit row is called a track. The reflected light from the track passes through the objective lens again, the optical system, and is converted into an electric signal by an optical semiconductor detector or the like.

In general, the disc is not flat but has distortion, and the rotating system is tilted with respect to the disc axis, so that the disc information surface moves closer to or farther from the optical system, thereby deviating the focus condition. Further, when the center of the disk and the center of the rotating system are eccentric or the track is distorted, the track touches the optical system to the left and right. In order to perform a stable operation, an automatic focus control function is generally provided for the former and an automatic tracking function for the latter. This is often done by moving only the objective lens vertically and horizontally. Therefore, the objective lens is configured as a movable element integrally with a driving movable portion for moving up and down and left and right. Generally, a moving coil in a magnetic field is often used for driving. Therefore, the mover is supported by the base using the rotating shaft and the deformable elastic body.

With the objective lens drive mechanism of the conventional optical pickup for CD,
As shown in FIG. 6 (a), the mover weights of some manufacturers are not balanced in either the focusing direction or the tracking direction. For other manufacturers, Fig. 6 (b),
As shown in FIG. 6C, mass balance is achieved in the tracking direction.

However, in neither case is mass balance in the focusing direction. This is to make the force point of the driving force coincide with the center of gravity of the mover in order to balance the dynamic mass of the objective lens or the mover. This is because if there is a dynamic imbalance, the mover surface, that is, the objective lens is tilted during focusing servo, and the quality of image formation is deteriorated. For this reason, the mover was forced to be in an unbalanced state with respect to gravity and external acceleration forces during shaking. Representative structures are shown in FIG. 6 (a), FIG. 6 (b), and FIG.
It is shown in Figure (c).

FIG. 6A shows an example of mass imbalance in both focusing and tracking. FIGS. 6 (b) and 6 (c) show examples in which tracking is mass balanced but focusing is unbalanced. In these figures, 1 is an objective lens, 17 is a movable body, 2 is a focusing driving moving coil, 3 is a tracking moving coil, 4 is a balancing mass, 19 is a rotating shaft sliding sleeve, 20 is a rotating shaft, and 21 is elastic. The rod and mesh hatched part 18 is the fixing part to the base, AC
B is an elastic parallelepiped.

In FIG. 6 (a), the movable body 17 holding the lens 1 is largely swung by vertical and horizontal gravity and external acceleration force. 6 (b) and 6 (c), since the movable body 17 is vertically swung because it is located at the tip of the elastic parallelepiped C or the shaft 20, the movable body 17 is moved to the left and right. Is immovable, and since it is mass-balanced with respect to the rotating shaft 20, it hardly oscillates. However, none of them are mass-balanced in the vertical direction, that is, in the focusing direction, so that they are largely shaken by an external force, the focusing condition of the optical system is disturbed, and it becomes impossible to read and reproduce information. This is designed so that the driving force point and the center of gravity coincide with each other when the mover weight is driven by a dynamic driving coil, but mass balance is performed against gravity or an accelerating force from the outside. Due to the absence.

In order to solve this problem, conventionally, as shown in FIG. 7, the optical block 100 and the balancing block 110 are connected by a rigid link 130, and the center of gravity G ₀ of the entire movable system (both blocks and the link) is approximately at the center of the link. There is a system in which the entire movable system is supported by a fixed base 45 in a seesaw shape by pivots 71a and 71b (Japanese Patent Laid-Open No. 61-133049).

In FIG. 7, each of the optical block and the balance block has coils 2 and 3 which are driven in the focus direction (Z direction) and the tracking direction (X direction).

In the focus direction drive, the in-block coil driving force resultant force passes through the centers of gravity G ₁ and G ₂ of the respective blocks in FIG. 7, and the centers of gravity are in the block support reference planes ac, bc and ad, bd of the link.

In the tracking direction drive, as shown in FIG.
There For respect G ₁ only one side, the driving force is the block center of gravity in G ₁
It doesn't go through. However, the center of gravity is within the block support reference planes ac and bc of the link.

(Problems to be Solved by the Invention) The conventional optical pickup shown in FIG. 6 has the following problems.

Although the movable body 17 including the objective lens of FIG. 6 is mass-balanced with respect to the driving force of the driving unit in both the focusing direction and the tracking direction, gravity or an accelerating force from the outside May not be mass-balanced for
In particular, since there is no equilibrium in the focusing direction, the information may not be read out when the user takes an operation posture in an unusual azimuth, is shaken, or receives an impact.

In particular, the portable type and the in-vehicle type have an operation posture in all directions and are subject to shaking and impact, so that stable operation is likely to be impaired. With compact discs, the number of in-car and portable types has increased,
It is required to have a free movement posture in all directions and to be stable against shaking, vibration and impact.

This request is solved by the conventional method shown in FIG. However, even in FIG. 7, there were the following problems.

． In concretely realizing the one shown in FIG. 7, since the optical block and the balance block are driven in a seesaw shape in the focus direction and the tracking direction, a complicated structure is taken. As shown in FIG. Pivots have to be used at the connection fulcrums 70-1 and 70-2 between both blocks and the link, and the connection fulcrums 71a and 71b between the link and the fixed base. The former can be replaced with a rotating shaft because it rotates in one direction, but the latter must be a pivot because it can rotate in two directions, the X direction and the Z direction. Since the sharp tip of the pivot serves as a fulcrum, the tip is easily worn and rattles.

Further, even in the initial assembly, the precision adjustment of the distance between the upper and lower pivots is delicate. If it is a little loose, play will occur, and if it is a little hard, the frictional force will increase and the drive sensitivity will decrease, and in either case, the transmission characteristics will deteriorate.

As a method without such backlash, as disclosed in JP-A-60-209935, a method utilizing bending of a thin portion is known, but in the balanced type, it is necessary to be movable in X and Z2 directions. Yes, it was difficult to construct with a thin hinge.

． Regarding FIG. 7, Japanese Patent Laid-Open No. 61-133049 discloses
The center of gravity of the blocks G ₁ and G in the blocks 100 and 110, respectively.
₂ , it is described that the block driving resultant force and the block supporting reference surface are the same in three in terms of driving in the focus direction. However, in the tracking direction, as shown in FIG. 7C, the center of gravity of the block and the support reference surface are coincident with each other, but the driving force in the tracking direction is out of the center of gravity thereof. The description differs from the direction. Therefore, in driving in the tracking direction, each block generates rotational vibration around the block centroids G ₁ and G ₂ . This causes a secondary resonance in the transfer characteristic or blurring of the optical axis.

． Further, in FIG. 7, in driving in the focus direction, in order to allow the resultant force in the focus direction to pass through the center of gravity of each block in each block, two sets of magnetic circuits and drive coils are provided for each block. Four sets are provided. This leads to an increase in cost. In addition, there is a drawback that the overall size is increased.

(Object of the Invention) The object of the present invention is to be able to operate in all azimuth postures while keeping the azimuth of the objective lens accurately, to operate stably against external shaking and impact, and to have low power consumption, An object is to provide a balanced movable device such as an inexpensive and small optical pickup. In a concrete structure, it is to provide a high-performance balanced type movable device in which a fulcrum is used with a less vibration and a vibration damping property, and the secondary vibration of each block is suppressed.

(Summary of the Invention) A balanced movable device such as an optical pickup according to the present invention includes an objective lens for autofocus focusing and automatic track following, and a drive mover for driving the objective lens (focusing control drive coil 2 and tracking coil). 3) The optical block 100 and the equilibrium block 110 provided with are connected before and after a parallel link 130 having a deformable parallel four reference plane structure, and a support block 120 provided between the parallel links 130 has a vertical rotation axis. Provide X ₁ and X ₂ ,
By arranging so that the mass balance can be perfectly achieved with respect to the operating directions of both blocks 100, 110, it is possible to operate in all azimuth postures while keeping the optical axis azimuth of the objective lens accurately, and vibration resistance, In a balanced movable device having impact resistance, in particular, by using hinges utilizing bending of thin members at all fulcrums, vibration is attenuated by eliminating play and friction.

In addition, in both the optical block and the balance block,
In each of the driving in the focus direction and the tracking direction, the driving force resultant force passes through the center of gravity of each block, and the center of gravity is within the support reference plane of each block. It is designed to suppress vibration.

The thin hinge structure is a generally known technique, and its application to a non-balanced type optical pickup is known, for example, from JP-A-60-209935. In the present invention, this thin hinge structure can be applied to a balanced complex structure.

(Means for Solving the Problems) A balanced movable device for an optical pickup according to claim 1 is characterized by having the following structures A to G.

(A) The optical block 100 is connected to the front of the parallel link 130, and the balance block 110 is connected to the rear of the parallel link 130.
A structure provided with a support block 120 for supporting the.

(B) The parallel link 130 includes an upper surface member 35, a lower surface member 36,
It is composed of a front surface member 37 and a rear surface member 38, and an upper reference surface a of the upper surface member 35, a lower reference surface b of the lower surface member 36, a front reference surface c of the front surface member 37 and a rear reference surface d of the rear surface member 38 are parallel to each other. Thin-structured first to fourth hinges that can be deformed while being held
Link structure connected by 22, 23, 24, 25.

(C) First hinge 22 and second hinge 23 at both ends of the upper surface member 35
An island portion A which is connected to the upper surface member 35 and is rotatable in the vertical direction by a fifth hinge 10 having a thin structure formed in parallel with the first and second hinges 22 and 23; A sixth hinge 13 having a thin structure which is parallel to the third hinge 24 and the fourth hinge 25 at both ends and is formed between the third and fourth hinges 24, 25 is connected to the lower surface member 36 to rotate in the vertical direction. A structure in which the movable island portion B is provided and the distance between the first hinge 22 and the fifth hinge 10 is equal to the distance between the third hinge 24 and the sixth hinge 13.

(D) In the optical block 100, the front base 30 is rigidly configured to include the front member 37 of the parallel link 130, and is rotated by the first hinge 22 and the third hinge 24 to the upper and lower members 35 and 36. Movably connected to the front base 30 with an objective lens,
A structure provided with a mounting portion 41 to which an optical member such as a mirror is attached.

(E) In the balancing block 110, the rear base 31 includes the rear surface member 38 of the parallel link 130 and is rigidly and integrally formed, and the upper and lower surface members 35 and 36 have the second hinge 23 and the fourth hinge 25.
Structure that is rotatably connected with.

(F) In the support block 120, the holding portion 56 and the connecting member E are connected by a thin seventh hinge 55 so that the connecting member E can be rotated around the seventh hinge 55. The left / right rotation axis Y is the vertical rotation axis X ₁ , X ₂ of the fifth and sixth hinges 10, 13.
The support block 120 is fixed to the mounting base, the connecting member E is attached to the islands A and B of the parallel link 130 to support the parallel link 130, and the optical block 100 and the balance block 110 are supported. A structure that can move up and down, left and right with respect to 120 support points in a seesaw shape.

(G) The fifth hinge 10 and the sixth hinge are located at positions where the primary mass moments of the front and rear masses are respectively balanced with respect to the vertical rotation axes X ₁ and X ₂ and the horizontal rotation axis Y in the vertical and horizontal directions. 1
3, the structure with the seventh hinge 55.

In the balanced type movable device of the optical pickup according to claim 2, the focusing control drive coil 2 is provided on the rear surface member 38,
The tracking coil 3 is provided.

(Operation of the Invention) The operation of the balanced movable device of the optical pickup of the present invention is as follows.

． When the balancing block 110 moves up and down and left and right by energizing the focusing control drive coil 2 and the tracking coil 3 of the drive unit of the balance block 110 by the seesaw motion of the parallel link 130 of the parallelepiped structure, the optical block Since the front board 30 of 100 is provided on the front reference plane c of the parallel link 130, the optical block 100 moves up and down and left and right while keeping its orientation. In this case, since the front and rear mass balance is balanced with respect to the vertical and horizontal seesaw rotation, it is not affected by gravity or external force. Although it is not balanced in FIG. 1 with respect to the driving force of the driving unit, the front base 30 does not tilt because it is the seesaw movement of the parallel link 130 with the pivot as the fulcrum.

． As will be described later, as shown in FIG. 5, the focusing control drive coil 2 and the tracking coil 3 are provided in front of the vertical rotation axes X ₁ and X ₂ and the horizontal rotation axis Y of the parallel link 130 so as to provide a mass moment. In addition to the equilibrium, the driving force moments can be made equal.

． The vertical movement of the rear base 31 of the balancing block 110 is the vertical movement of the front base 30 of the optical block 100 due to the seesaw movement of the parallel link 130 with the vertical rotation axes X ₁ and X ₂ as fulcrums. At this time, since the parallel links 130 have a parallelepiped structure, the upper surfaces of the front base 30 and the rear base 31 are always kept horizontal.

． Since the horizontal rotation axis Y is orthogonal to the vertical rotation axes X ₁ and X ₂ , the horizontal movement of the rear base 31 is a seesaw movement with the horizontal rotation axis Y as a fulcrum, similarly to the vertical movement. Front base
30 movements to the left and right. In this case also the front base 30,
The upper surface of the rear base 31 is always kept horizontal. Therefore, the focusing control causes the objective lens attached to the front substrate 30 to move up and down, and even if the objective lens moves to the left or right for tracking, the objective lens is always kept horizontal, that is, the optical axis Yo is kept vertical, and image formation deteriorates. Does not occur.

． Further, in the invention of claim 1, since all the movable fulcrums are formed by bending the thin portion of the hinge, it is possible to eliminate the backlash and frictional force found in the pivot and the sliding rotary shaft. Moreover, since the thin portion of the material can be a viscoelastic body, it can be used for absorbing and damping secondary vibrations.

(Embodiment) FIG. 1 is a principle diagram of an objective lens moving mechanism in a first embodiment of a balanced movable device such as an optical pickup according to the present invention.

Reference numeral 130 in FIG. 1 is a parallel link having a parallel four reference plane structure.
This is composed of an upper reference plane a and a lower reference plane b as mutually parallel links, a front reference plane c and a rear reference plane d which are parallel to each other, and an upper reference plane a, a lower reference plane b, a front reference plane c, The rear reference surface d can be bent by the reference axes ac, ad, bc, and bd to be parallel and deformable.

A mounting hole 41 for mounting an objective lens and a balancing mass 44 are formed on the front substrate 30. The balancing mass 44 is formed by bending the front end of the front base 30 downward.

A drive unit 61 mainly including a focusing control drive coil 2 for vertically moving the objective lens and a tracking coil 3 for horizontally moving the objective lens is fixed to the rear substrate 31.

In FIG. 1, 47 is a permanent magnet, and 46-1 and 46-2 are yokes. The magnetic field goes from 46-1 to 46-2. When assembled, the yoke 46-1 is inserted inside the focusing control drive coil 2.

X _1, X ₂ of FIG. 1 is a vertical rotation axis, the reference axis ac, is parallel to the bc etc., equal to the distance Ac～X ₁ and bc~X _2.

In FIG. 1, Y is a left / right rotation axis, which is a vertical rotation axis X ₁ ,
The upper reference plane a and the lower reference plane b of the parallel link 130 orthogonal to X ₂
Is almost in the center in the width direction of the base plate, and the lower end is held vertically by the member 45 on the base.

As described above, the present invention provides a parallel link having a parallel four reference plane structure.
By moving the 130 in a seesaw motion and balancing the mass both forward and backward with respect to both the focusing and tracking directions, the objective lens can be moved in both directions without tilting, and the effects of gravity and external acceleration forces can be eliminated. Do not receive and drive 61
With respect to the unbalance of the driving force of the above, the parallel four reference plane structure with the vertical rotation axes X ₁ and X ₂ and the horizontal rotation axis Y as fulcrums prevents the tilt of the objective lens and solves the conventional problems. To do.
Of course, as will be described later, the driving force moment is also the vertical rotation axis.
X _1, may be equilibrated before and after the X ₂ and left and right rotation axes Y.

FIG. 2 is a concrete example of the first embodiment of the present invention. In FIG. 2, the focusing control drive coil 2, the tracking coil 3 and the permanent magnets 46 and 47 in FIG. 1 are omitted.

Reference numeral 30 in FIG. 2 designates a front base on which an objective lens is loaded, which extends horizontally at a right angle to the front reference plane c and has a front end portion which is suspended to form a balance mass 44.

Reference numeral 31 in FIG. 2 denotes a rear base for mounting the focusing control drive coil 2 and the tracking coil 3, which extends horizontally at a right angle to the rear reference plane d.

In FIG. 2, ac, ad, bc, and bd are reference axes, which are moved up and down by thinning the boundaries of the members 35, 36, 37, 38 forming the reference surfaces a, b, c, d. It can be bent.

Holes 48 and 49 are formed in the upper reference surface a, and an island portion A is formed in the hole 49, and the island portion A is connected to the upper reference surface a by the connecting portion 10. The connecting portion 10 has a narrow thin wall (hinge), and can be pivoted up and down by bending the hinge to serve as a vertical pivot axis X ₁ .

Holes 51 and 52 are formed in the lower reference surface b, an island portion B is formed in the hole 52, and the island portion B is connected to the lower reference surface b by the connecting portion 13. The connecting portion 13 has a thin wall (hinge), and can be pivoted up and down by bending the hinge to serve as a vertical pivoting axis X ₂ .

A connecting member E is inserted between the lower surface of the island portion A and the upper surface of the island portion B, and the connecting member E is fixed to the island portions A and B by means such as fitting and bonding so that they are integrated. Be converted. The connecting member E is thin-walled, vertical, and connected to the base holding portion 56 via a narrow connecting portion 55. The connecting portion 55 forms the left-right rotation axis Y of the parallel link 130 as shown in FIG. Connecting member E
Are islands A and B due to injection molding
It may be integrally molded with. In the case of FIG. 2, they are shown separately for the sake of illustration.

The holding portion 56 is press-fitted between the sandwiching members 63 and 64 formed of an elastic material, and the sandwiching members 63 and 64 are formed into holes using the elasticity of the holding portion 56.
By being inserted into 48 and 51, the parallel link 130 is fixed to the sandwiching members 63 and 64 following the mounting base 45 (FIG. 5) which is a separate body.

In FIG. 2, assuming a vertical rotation axis X ₁ , X ₂ (horizontal direction) and a Z axis (front-back direction) orthogonal to the horizontal rotation axis Y (vertical direction), all movers are symmetrical with respect to the Z axis. It is possible to reduce the mass imbalance around the Z-axis, though it is not symmetrical in the vertical direction. If necessary, it is possible to balance the mass up and down.

It is necessary to add a balancing mass (front hanging part) 44 around the vertical rotation axes X ₁ and X ₂ and around the horizontal rotation axis Y when the target mass arrangement cannot be performed. Is.

If the vertical rotation axes X ₁ and X ₂ and the horizontal rotation axis Y are made orthogonal to each other in the same plane, if the mass balance is made around the vertical rotation axes X ₁ and X ₂ , it will rotate simultaneously to the left and right. Mass balance has been achieved around axis Y. If the position of the plane including the vertical rotation axes X ₁ and X ₂ and the horizontal rotation axis Y is moved back and forth in the Z-axis direction while maintaining the azimuth, mass balance can be obtained without using the balancing mass 44. However, conversely, the balancing mass 44 may be added to the rear base 31 side.

In this way, swinging about the vertical rotation axes X ₁ and X ₂ and the horizontal rotation axis Y does not occur due to gravity or external acceleration from all directions, and the rotation around the Z axis assumed in FIG. Since there is no rotation axis in the and is fixed by the thin connecting part 55, it is not necessary to equilibrate originally, but further imbalance is reduced around the Z axis, and the thin connecting part 55
It is also possible to reduce the torsional deformation of the element, or to balance the element around the Z-axis to make the torsional element of zero.

The driving force is not balanced around the X and Y axes with respect to the forces from the coils 2 and 3, but due to the seesaw motion with the vertical rotation axes X ₁ and X ₂ and the horizontal rotation axis Y as fulcrums. There is no problem in keeping the lens surface horizontal.

As described above, the advantage of using the thin structure is that the error and the frictional force due to the air gap in the joint portion of a plurality of parts are removed, and the effect of reducing the number of parts by integration is obtained.

The upper reference plane a, the front reference plane c, the lower reference plane b, the rear reference plane d, the front base 30, the rear base 31, the islands A and B in FIG. 2 are integrally formed as one part by the injection molding method or the like. can do. By doing so, the number of parts is significantly reduced, which is effective in reducing the price.

The movable portion 61 for driving, which is composed of the coils 2 and 3 and the rear base 31 shown in FIG. 1, is configured as a balancing block 110 such that its center of gravity and / or center of driving force is in the rear reference plane d. By doing so, it is possible to reduce the occurrence of dynamic distortion during driving, improve accuracy and improve dynamic characteristics.

The present invention can also be configured as shown in FIG. As shown in FIG. 3, this is an optical block 100 composed of a front substrate 30 and a lens mounted on a lens mounting portion 41 thereof.
The center of gravity is configured to be within the front reference plane c as shown in FIG. 5, thereby reducing the occurrence of dynamic distortion of the lens unit itself, improving accuracy and improving dynamic characteristics. You can

In FIG. 5, the driving movable portion 61 is also provided in the front to balance the driving force in the front-rear direction.

In addition, as shown in FIG. 5 which is the second embodiment, the drive movable portion 61 composed of the drive coils 2 and 3 shown in FIG. 4 and the substrate 31 shown in FIG. Is also newly provided on the front reference plane c side, and by arranging one piece 46-1 of the magnet 46 to be inserted into the focusing control drive coil 2, the vertical rotation axes X ₁ , X ₂ , left and right Movable part for front-back drive with respect to the rotation axis Y
By making the driving force moments of 61 equal, and making the moment of inertia of the front system equal to the moment of inertia of the rear system, the occurrence of dynamic strain in the system is reduced,
Improved accuracy and improved dynamics can be obtained.

In this case, the front driving movable part may be integrated with the optical block 100, and the rear driving movable part may be integrated with the balancing block 110.

Reference numeral 44 in FIG. 5 is a mass for balancing the primary and moment of inertia with respect to the mass of the lens portion. The balancing mass 44 may be provided on the front substrate 30 side in FIG. 6 to have a front-back (left-right) symmetrical structure. In the embodiment shown in FIG. 2 of claim 1, all the rotating shafts are realized by using the bending of a narrow thin structure (hinge), but twisting may be used.

The above description is all about the case of an optical pickup in which focusing control and tracking are performed by moving the objective lens, but the present invention is also possible by moving a mirror, a prism or the like, and the present invention moves them. It also includes cases. Although the moving coil is used as the driving method in the above description, it goes without saying that the driving method may be a moving magnet.

(Effects of the Invention) A movable device such as an optical pickup of the present invention has the following general effects (1) to (5) as a balanced type, and in addition, has the effects (6) to (8) in particular.

(1) It has high movement accuracy and is stable against gravity, shaking, and impact.

(2) The movable device has low power consumption, a large optical system coupling space, and a small number of parts.

(3) Stable suitable not only for stationary type but also for portable type, in-vehicle type, etc.
It is a low-power, inexpensive mobile device.

(4) When used in a portable device or an in-vehicle device, the instability due to use in any omnidirectional posture, shaking, and impact is eliminated.

(5) Focusing control power to withstand gravity can be reduced to zero, extending the usable time of portable equipment using a battery as a power source, and using a small battery to reduce weight and size. To help.

(6) Since the movable fulcrum is composed of a thin hinge, voids (backlash) and friction are removed. In addition, secondary vibration is also absorbed.

(7) The optical block and the balance block do not generate rotational vibration around their respective centers of gravity.

(8) Since only two sets of coil magnetic circuits are needed, the weight, size, and cost are reduced as compared with the four sets shown in FIG.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of the movable device of the present invention, FIG. 2 is a perspective view showing an embodiment of the movable device, and FIGS. 3 to 5 are explanatory views of a technique related to the present invention, and FIG. FIG. 7 is a diagram of a conventional optical pickup, FIG. 7 (A) is a plan view,
(B) is a side view, (C) is a plan view of an optical block portion,
(D) is a detailed view of the link support portion. 2 is a drive coil for focusing control 3 is a tracking coil 44 is a balanced mass 100 is an optical block 110 is a balanced block 120 is a support block 130 is a parallel link a, b, c and d are reference planes ac, ad, bc and bd Reference axes X, X ₁ and X ₂ are vertical turning axes Y are horizontal turning axes A and B are islands E is a connecting member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideaki Ishizuke 1-19-16 Omorikita, Ota-ku, Tokyo Inside Tajiri Machine Industry Co., Ltd. (56) References JP-A-61-133049 (JP, A) JP-A-SHO 60-209935 (JP, A)

Claims (2)

[Claims] 1. A balanced movable device for an optical pickup having the following structures A to G. (A) The optical block 100 is connected to the front of the parallel link 130, and the balance block 110 is connected to the rear of the parallel link 130.
A structure provided with a support block 120 for supporting the. (B) The parallel link 130 includes an upper surface member 35, a lower surface member 36,
It is composed of a front surface member 37 and a rear surface member 38, and an upper reference surface a of the upper surface member 35, a lower reference surface b of the lower surface member 36, a front reference surface c of the front surface member 37 and a rear reference surface d of the rear surface member 38 are parallel to each other. Thin-structured first to fourth hinges that can be deformed while being held
Link structure connected by 22, 23, 24, 25. (C) First hinge 22 and second hinge 23 at both ends of the upper surface member 35
An island portion A which is connected to the upper surface member 35 and is rotatable in the vertical direction by a fifth hinge 10 having a thin structure formed in parallel with the first and second hinges 22 and 23; A sixth hinge 13 having a thin structure which is parallel to the third hinge 24 and the fourth hinge 25 at both ends and is formed between the third and fourth hinges 24, 25 is connected to the lower surface member 36 to rotate in the vertical direction. A structure in which the movable island portion B is provided and the distance between the first hinge 22 and the fifth hinge 10 is equal to the distance between the third hinge 24 and the sixth hinge 13. (D) In the optical block 100, the front base 30 is rigidly configured to include the front member 37 of the parallel link 130, and is rotated by the first hinge 22 and the third hinge 24 to the upper and lower members 35 and 36. A structure in which a mounting portion 41 is provided that is movably connected and to which optical members such as an objective lens and a mirror are attached to the front substrate 30. (E) In the balancing block 110, the rear base 31 includes the rear surface member 38 of the parallel link 130 and is rigidly and integrally formed, and the upper and lower surface members 35 and 36 have the second hinge 23 and the fourth hinge 25.
Structure that is rotatably connected with. (F) In the support block 120, the holding portion 56 and the connecting member E are connected by a thin seventh hinge 55 so that the connecting member E can be rotated around the seventh hinge 55. The left / right rotation axis Y is the vertical rotation axis X ₁ , X ₂ of the fifth and sixth hinges 10, 13.
The support block 120 is fixed to the mounting base, the connecting member E is attached to the islands A and B of the parallel link 130 to support the parallel link 130, and the optical block 100 and the balance block 110 are supported. A structure that can move up and down, left and right with respect to 120 support points in a seesaw shape. (G) The fifth hinge 10 and the sixth hinge are located at positions where the primary mass moments of the front and rear masses are respectively balanced with respect to the vertical rotation axes X ₁ and X ₂ and the horizontal rotation axis Y in the vertical and horizontal directions. 1
3, the structure with the seventh hinge 55. 2. The balanced movable device for an optical pickup according to claim 1, wherein the rear surface member 38 is provided with a focusing control drive coil 2 and a tracking coil 3.