JPH1173661A - Optical part supporting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the stable operation of a supporting device by supporting an optical part with three lines of supporting wires parallel with each other in which a stipulated plane becomes one and an excess stressis not imparted on the wires in operation. SOLUTION: An optical part 1 is movably supported with three lines of first and second supporting wires 5, 5, 10 to make it slightly swingable in the up-and-down direction and in the horizonal direction with repulsive force. Thickness of the second supporting wire 10 is made thicker than that of the two lines of the first supporting wires 5, 5 and the rigidity of it is also made equal to the synthesized rigidity of the two lines of the first supporting wires 5, 5. The synthesized position of the two lines of the first supporting wires 5, 5 and the second supporting wire 10 are set symmetrically holding the center of gravity of the optical part 1. For example, when the optical part 1 is minutely swung or moved in the radial direction of an optical disk by stopping a movable base 6 with a tracking fine adjustment, since only one plane of the part 1 is stipulated because the part 1 is supported by three points and the synthesized rigidity of the wires 5, 5 and the rigidity of the wire 10 are set equally, an inclined degree characteristic expressing the relation ship between the angle of the optical axis deviation of an objective lens 3 before and after the movement and the moving quantity of the part becomes a straight line to facilitate the assembling adjustment of the optical part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supporting device for supporting an optical component such as an optical pickup by a parallel wire system.

[0002]

2. Description of the Related Art Generally, an optical pickup is used as an optical component for reading and writing information from and on an optical disk such as a CD (compact disk) and a DVD (digital versatile disk). This optical pickup is horizontally supported by, for example, four support wires, and is moved in the radial direction of the optical disk while moving the optical pickup in the focal direction or the disk radial direction in accordance with a focus signal or tracking signal. It is made movable. Such an optical pickup support device is disclosed in, for example, Japanese Utility Model Registration No. 2521564 or the like, and will be described with reference to the drawings.

FIG. 8 is a perspective view showing a conventional optical device support device, FIG. 9 is a plan view of the support device shown in FIG. 8, and FIG. 10 is a side view of the support device shown in FIG. As shown in the drawing, an optical component 1 constituting an optical pickup is configured by mounting an objective lens 3 at a center portion of a holder 2 having a substantially rectangular shape, and the objective lens 3 is arranged to face an optical disc (not shown). You. Protrusions 4, 4 are provided at substantially center portions on both sides of the holder 2, and a total of four flexible support wires 5 are provided from each of the protrusions 4, 4.
It extends parallel to the horizontal direction, and its end is
It is fixed to. As a result, the optical component 1 is movably supported by the four support wires 5 and can be slightly swung in the horizontal and vertical directions by the elastic force of the support wires 5.

A pair of focus coils 13 and tracking coils 14 are wound on both sides of the holder 2, and a focus error signal and a tracking error signal are supplied to these coils so as to be interposed between a magnet (not shown). Due to the generated electromagnetic force, the entire optical component is slightly adjusted in the disk direction or the disk radial direction. The holder 2 has a rectangular yoke window 7 through which a yoke erecting from a pickup base (not shown) is inserted.
Is formed. The movable base 6 is attached to a pickup pace (actuator base), not shown, so that the entire movable base 6 can move in the radial direction of the optical disk, that is, in the tracking direction (X direction).

[0005]

Incidentally, as described above, the optical component 1, which is an optical pickup, is supported by four support wires 5 arranged symmetrically in the vertical and horizontal directions. The point is that it is difficult to arrange the four support wires 5 with perfect symmetry. If there is any error in the length or position of these support wires 5, the movement of the support wires 5 will be hindered. The reason for this is that one plane is originally determined by three points, but this is determined by four points. The fact that there are four support points means that a maximum of four planes can be considered as a plane determined by extracting three arbitrary points from the four points, and this causes inconsistency.

That is, if two diagonal support wires of the four support wires 5 receive a tension, the other two diagonal support wires receive a compressive force, and the two support wires 5 receive a compression force. When one of the wires buckles, one plane determined by the other three support wires becomes dominant and one state is determined. And there are four states. In an actual mounting state of the support wire 5, there is always an error in the length, the connection position, and the like, and for example, an S-shaped inclination characteristic as shown in FIG. 11 is exhibited. Here, the movement amount is shown in FIG.
In addition, the optical component 1 is bent by bending the support wire 5 in a state where the movable base 6 is fixed in FIG.
Is the amount moved in the X or Z direction, and the angle indicates the angle between the optical axis of the pickup and the central axis of the objective lens 3.
FIG. 10 shows a case where the normal line 8 and the optical axis 9 coincide with each other.

In this case, at the time of assembling adjustment, the light spot on the light receiving element (not shown) of the optical pickup is adjusted to the K point at an angle of 0 so that the coma aberration is minimized. There are some points, and the point K is not at the approximate average position of the whole, but rather biased to the end. Therefore, when the optical component 1 is moved up and down or left and right, the optical component 1 is greatly inclined. In addition, since the tilt during the operation also moves in an unstable manner, there is a disadvantage that the operation becomes unstable such as an increase in jitter. In addition, there is a problem that productivity is poor because adjustment takes time. FIG. 12 shows the optical component 1 at this time.
FIG. 3 conceptually shows the fluctuation of the S-shaped inclination characteristic of the optical axis 9, and the direction of the optical axis 9 greatly changes left and right a plurality of times according to the change of the movement amount. FIG. 13 conceptually shows the fluctuation with respect to the V-shaped inclination characteristic. In this case as well, the direction of the optical axis 9 fluctuates largely right and left according to the change of the movement amount. FIG. 14 shows the characteristics of the optical component when assembled properly without any error, and there is no inclination during operation.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been made in order to solve the problems effectively. It is an object of the present invention to provide an optical component which is easy to adjust and can suppress unstable operation. It is to provide a support device.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a supporting device for supporting an optical component in a swingable manner, wherein the optical component is supported by three parallel supporting wires. You. As a result, the optical component is supported at three points, so that only one plane is defined, and no excessive stress is applied during operation, and stable operation is possible. Further, the present invention provides a supporting device for swingably supporting an optical component, wherein two first supporting wires provided in parallel to support one side of the optical component, A second support wire having twice the rigidity and supporting the other side of the optical component.

Accordingly, the optical component is swingably supported by the two first support wires and the one second support wire. And the second support wire is the first support wire.
Since the support wire has twice the rigidity of the support wire, the combined rigidity of the two first support wires and the one second
The stiffness of the support wire is mechanically equivalent and therefore
Both sides of the optical component will be supported with equal rigidity. In this case, since the optical component is supported at three points instead of four points, only one plane is determined by these three points. Therefore, when the optical component is moved, excessive stress is applied to each support wire. And the unstable operation can be suppressed. The mechanically combined position of each of the three support wires passes through the center of gravity of the optical component.

Further, since the inclination characteristic of the optical component is substantially linear, the mounting adjustment work can be easily performed.
In this case, the operation of the optical component is further stabilized by setting the combined position of the two first support wires and the second support wire to be symmetrical with respect to the center of gravity of the optical component. Can be. The direction of symmetry of the support wire is set to be substantially perpendicular to the optical axis of the optical component. As this optical component, an optical pickup that reads information from an optical disk can be applied.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an optical component supporting apparatus according to an embodiment of the present invention. FIG. 1 is a perspective view showing a device for supporting an optical component of the present invention, and FIG.
Is a plan view of the support device shown in FIG. 3, and FIG. 3 is a side view of the support device shown in FIG. The same parts as those of the conventional apparatus shown in FIGS.

As shown in the figure, an optical component 1 constituting an optical pickup is configured by mounting an objective lens 3 at the center of a holder 2 having a substantially rectangular shape, and this objective lens 3 is mounted on an optical disk (not shown). They are arranged facing each other. Protrusions 4, 4 are provided at substantially center portions on both sides of the holder 2, and from one of the protrusions 4, 2
One flexible support wire 5 extends in parallel with the horizontal direction, and one flexible support wire 10 as a second support wire extends in the horizontal direction from the other convex portion 4. They extend in parallel and each end is fixed to the movable base 6. Thereby, the optical component 1 is movably supported by the three support wires 5, 5, and 10,
It can be slightly swung in the horizontal and vertical directions by the resilience of the support wires 5, 5, 10.

Specifically, the second support wire 10 is formed to be slightly thicker than the first support wire 5, and
The support wire 5 has the same rigidity as the combination of the two first support wires 5, that is, a spring constant. Then, the two first support wires 5,
5 and the second support wire 10 are positioned symmetrically with respect to the center of gravity G of the optical component 1 as a movable part, that is, a line segment extending through the center of gravity G and parallel to the support wire. 11 is set to be line-symmetrical. Furthermore, the symmetrical direction of the first support wires 5, 5 and the second support wire 10 is, in this example, the optical component 1
Are set so as to be substantially perpendicular to the central axis 9. Therefore, the spring constant is symmetrical in the vertical and horizontal directions with respect to the center of gravity G of the optical component 1 which is a movable part. The first
The positional relationship between the support wires 5, 5 and the second support wire 10 may be reversed in the figure. Therefore, no matter how the optical component 1 swings up and down, left and right,
The movement can be relatively stable with little fluctuation.

On the other hand, a pair of focus coils 13 and a tracking coil 14 are wound on both sides of the holder 2, and a focus error signal and a tracking error signal are supplied to these coils so as to be connected to a magnet (not shown). Due to the electromagnetic force generated therebetween, the entire optical component is slightly adjusted in the disk direction or the disk radial direction. Each of the support wires 5, 5, and 10 is also used as a conductor for passing electricity through each of the coils. Also,
The holder 2 is formed with a rectangular yoke window 7 through which a yoke erecting from a pickup base (not shown) is inserted. The movable base 6 is attached to a pickup base (actuator base) (not shown).
The whole can be moved in the radial direction of the optical disk, that is, in the tracking direction (X direction).

Next, the operation of the apparatus configured as described above will be described. For example, by fine-tuning the tracking,
Assuming that the optical component 1 slightly swings or moves in the X direction (radial direction of the optical disk) in a state where the movable base 6 is substantially stopped, assuming that the deviation angle of the optical axis of the objective lens 3 before and after the movement and the amount of movement. The gradient characteristics indicating the relationship are different from the conventional characteristics shown in FIGS. 12 and 13 and are linear as shown in FIG.
The reason is that the conventional optical component 1 is held by a four-point support that defines a plurality of planes, whereas the present invention uses a three-point support that can define only one plane in the present invention. The combined rigidity (spring constant) of the two first support wires 5, 5 held and the
This is because the rigidity (spring constant) of the first support wires 10 is set to be the same.

As described above, since the inclination characteristic is straight and straight, the portion where the angle of 0 crosses the inclination characteristic is one, and the best point can be quickly determined at the time of assembling and adjusting the optical component 1. And productivity can be greatly improved. Further, from the above points, even during the operation of the optical component 1, the degree to which the optical component 1 fluctuates is reduced, and the stability is relatively improved.
The occurrence of jitter can also be suppressed. FIG. 5 conceptually shows wobble with respect to the inclination characteristic of the optical component supported by the apparatus of the present invention, and the direction of the optical axis 9 fluctuates left and right according to the change in the amount of movement. It can be seen that the degree of fluctuation and the degree of fluctuation are much suppressed as compared with the fluctuations of FIGS. 12 and 13 showing the case of the conventional device. Here, the tilt angle in the X direction is described as an example, but the same applies to the Z direction. Although the optical pickup has been described as an example of the optical component, the present invention can be applied to the optical component of an optical recording apparatus. Here, the first support wires 5 and 5 have the same rigidity, but the first support wires 5 and 5 are not limited thereto, and may have different rigidities.
That is, even if the three support wires have different stiffnesses, or if all three support wires have the same stiffness, they may be attached so that their mechanical combined position passes through the center of gravity G.

Therefore, a mode shown in FIG. 6 can be considered as a mode of support by three support wires. In the figure, black circles and white circles indicate support wires. FIG. 6A shows two supporting wires 20 and 20 having the same rigidity and one supporting wire 21.
Are shown on the left and right sides of the optical component 1, and FIG.
FIG. 6C shows a mode in which the support wires 20, 20, 21 are arranged above and below the optical component 1, and FIG.
FIG. 6D shows an aspect in which three support wires 22, 23, 24 are arranged at asymmetric positions, and FIG. 6D shows an aspect in which three support wires 25, 25, 25 having the same rigidity are arranged asymmetrically. However, in all aspects, the mechanically combined position of the three support wires passes through the center of gravity G.
This means that in FIG. 7, the spring constants and coordinates of the three support wires are denoted by a1, a2, a3 and (x1, y, respectively).
1), (x2, y2), and (x3, y3) mean that the following equation is satisfied when the center of gravity G is set to the origin (0, 0).

A1.x1 + a2.x2 + a3.x3 = 0 a1.y1 + a2.y2 + a3.y3 = 0 Thus, the function and effect of the present invention can be exhibited with any rigid supporting wire if the above expression is satisfied. .

[0020]

As described above, according to the optical component supporting apparatus of the present invention, the following excellent operational effects can be exhibited. Since the optical component is supported by the three support wires, not only the instability during the swing operation can be suppressed, but also the adjustment operation at the time of assembly can be performed quickly, and the production Performance can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a supporting device for an optical component of the present invention.

FIG. 2 is a plan view of the support device shown in FIG.

FIG. 3 is a side view of the support device shown in FIG.

FIG. 4 is a graph showing a gradient characteristic of the optical component support device of the present invention.

FIG. 5 is a diagram conceptually showing a fluctuation with respect to a gradient characteristic of an optical component supported by the apparatus of the present invention.

FIG. 6 is a diagram showing an arrangement of three support wires.

FIG. 7 is a diagram for explaining a mechanically combined position of a support wire.

FIG. 8 is a perspective view showing a conventional optical component support device.

9 is a plan view of the support device shown in FIG.

FIG. 10 is a side view of the support device shown in FIG.

FIG. 11 is a graph showing a gradient characteristic of a conventional optical component support device.

FIG. 12 is a diagram conceptually showing a fluctuation with respect to an S-shaped inclination characteristic of an optical component.

FIG. 13 is a diagram conceptually showing a fluctuation with respect to a V-shaped inclination characteristic.

FIG. 14 is a diagram conceptually showing operating characteristics of optical components assembled properly.

[Description of Signs] 1 ... optical parts, 2 ... holder, 3 ... objective lens, 5 ... support wire (first support wire), 6 ... movable base, 9 ...
Optical axis, 10 ... support wire (second support wire), G ...
Center of gravity.

Claims (6)

[Claims] 1. A supporting device for swingably supporting an optical component, wherein the optical component is supported by three support wires parallel to each other. 2. A supporting device for swingably supporting an optical component, comprising: two first support wires provided in parallel to support one side of the optical component; An optical component support device, comprising: one second support wire having twice the rigidity and supporting the other side of the optical component. 3. The optical component supporting apparatus according to claim 1, wherein the mechanically combined position of each of the three supporting wires passes through the center of gravity of the optical component. 4. The apparatus according to claim 2, wherein a position where the two first support wires are combined and a position where the one first support wire is symmetric with respect to a center of gravity of the optical component. Or the support device for an optical component according to 3. 5. The optical component supporting device according to claim 4, wherein a symmetric direction of the support wire is substantially perpendicular to an optical axis of the optical component. 6. The optical component supporting device according to claim 1, wherein the optical component is an optical pickup that reads and writes information from and on an optical disk.