JPH0426977Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to an optical pick-up device for optically picking up information recorded on a disk. The present invention relates to an optical pickup device that can be used.

(B) Prior Art An optical pickup device is known that uses a light beam to extract information from a digital audio disk on which unevenness corresponding to a digital signal is engraved. In the optical pickup device, it is necessary to perform tracking control and focusing control of the objective lens in order to correctly project the light beam onto the irregularities on the disk. In order to perform the tracking control and focusing control, a lens holder with an objective lens attached must be movably attached to the frame. A common method is to support the lens holder using a support body having:

Furthermore, in order to correctly project a light spot onto the disk, if the light beam is projected perpendicularly onto the disk, the objective lens must be placed at right angles to the axis of the light beam. That is, if the objective lens is tilted with respect to the optical axis, the light spot will spread in the jitter direction or in the tracking direction, making it impossible to pick up information correctly. Therefore, in general, the bottom surface of the frame that supports the lens holder is made spherical, and the receiving part of the pick-up body that holds the frame is made spherical, and the positions of the two are adjusted. It was controlling its posture.

(c) Problems to be solved by the invention However, the method of supporting the lens holder using a viscoelastic support has a problem in that it is susceptible to twisting. In addition, the method of controlling the lens posture by adjusting the positional relationship between the spherical bottom surface of the frame and the spherical receiving part of the pickup body cannot independently adjust the jitter direction and the tracking direction. If one is correct, the other may become misaligned, and the adjustment is troublesome.

(d) Means for solving the problems The present invention was developed in view of the above points, and uses four support wires to support the lens holder and also controls the attitude of the objective lens in the tracking direction. The present invention is characterized in that this is performed by rotating the substrate to which one end of the support wire is fixed.

(E) Effect According to the present invention, if the substrate is rotated to control the attitude of the objective lens and then the substrate is fixed to the frame, the position of the objective lens is always maintained correctly by the tension of the support wire. . Further, the attitude control of the objective lens in the jitter direction and the attitude control in the tracking direction can be performed independently.

(F) Embodiment FIG. 1 is a perspective view showing an embodiment of the present invention.
Reference numeral 1 denotes a lens holder in which an objective lens 2 is arranged and fixed in an integrally molded cylinder 1a, 3 a tracking coil wound around the lens holder 1, and 4 a focusing coil wound around the lens holder 1. Coil, 5 is a frame, 6 to 9 are the frames 5
first to fourth support wires 10 for supporting the lens holder 1;
A printed circuit board for fixing one end of the support wires 6 to 9, and a hole member 11 having holes 11a into which the other ends of the first to fourth support wires 6 to 9 are inserted. However, the printed circuit board 1
0 is fixed to the frame 5 by screws 12 that are tightened in the same direction as the axial direction of the first to fourth support wires 6 to 9,
One end of the fourth support wires 6 to 9 passes through the hole 5a of the frame 5 and connects to the printed circuit board 10.
It is fixed by soldering. Further, the hole member 11
are fixed to the frame 5 by screws 13, and the other ends of the first to fourth support wires 6 to 9 pass through the holes 5b filled with the dumping material of the frame 5 to the holes 11a of the hole member 11. is inserted into. Further, the first to fourth support wires 6 to 9 are made of conductive metal elastic wires such as phosphor bronze, and the first and second support wires 6 and 7 are electrically connected to the ends of the tracking coil 3. The third and fourth support wires 8 and 9 are electrically connected to the ends of the focusing coil 4 . The frame 5 is made of aluminum die-cast and has conductivity, but the holes 5a and 5
b is sufficiently large, and the first to fourth support wires 6
There is no direct contact with 9 to 9. Furthermore, since the hole member 11 is made of synthetic resin, no short circuit will occur even if it comes into contact with the first to fourth support wires 6 to 9.

Now, in order to perform tracking control, a tracking signal input terminal (not shown) of the printed circuit board 10 is connected.
When a tracking control signal is applied to , the control signal is supplied to the tracking coil 3 via the first and second support wires 6 and 7, and the lens holder 1 moves in the tracking direction (arrow A-A'). At this time, the moving direction of the lens holder 1 is determined by the polarity of the applied control signal, and the moving distance is determined by the magnitude of the control signal. Further, in order to perform focusing control, when a focusing control signal is applied to a focusing signal input terminal (not shown) of the printed circuit board 10, the control signal is transmitted to the tracking coil 4 via the third and fourth support wires 8 and 9. supplied to,
Lens holder 1 is in the focusing direction (arrow B
−B′). At this time, the moving direction of the lens holder 1 is determined by the polarity of the applied control signal, and the moving distance is determined by the magnitude of the control signal.

When assembling the optical pickup device shown in FIG. is fixed to frame 5. The first end is fixed to the printed board 10.
The other ends of the fourth support wires 6 to 9 are connected to the hole member 11 through the hole 5a of the frame 5, the hole of the holding part 1b of the lens holder 1, and the hole 5b of the frame 5.
into the hole 11a. Thereafter, the first to fourth support wires 6 to 9 and the holding part 1b of the lens holder 1 are glued together, the printed circuit board 10 is fixed to the frame 5 with screws, and the objective lens 2 is inserted into the cylinder 1a of the lens holder 1. Once you place the , assembly is complete.

Next, attitude control of the objective lens 2 will be explained. The objective lens 2 is a cylinder 1a of the lens holder 1.
The light beam is not necessarily positioned at right angles to the axis of the light beam. Therefore, it is necessary to adjust the angle of the objective lens 2 so that the objective lens 2 is perpendicular to the axis of the light beam. The tracking direction is adjusted by adjusting the positional relationship with the receiving portion of the main body (not shown) and by rotating the printed circuit board 10. The adjustment in the jitter direction is achieved by forming a curved surface in the jitter direction on the bottom surface of the frame 5, and also forming a curved surface corresponding to the receiving portion of the pickup body, and adjusting the positional relationship between the two. Further, the adjustment of the tracking direction is achieved by loosening the screws 12 that fix the printed circuit board 10 to the frame 5 and rotating the printed circuit board 10 around the screws 12. The screw 12 is attached to the objective lens 2.
It is attached and fixed at a position that approximately coincides with the principal point (the center point of the objective lens). That is, as shown in FIG.
It is also arranged at a position that substantially coincides with the principal point of the objective lens 2. Therefore, when the printed circuit board 10 is rotated around the screw 12, the first to fourth support wires 6 to 9 are moved from the apex positions of the rectangle shown by the four solid lines to the rectangle shown by the four dashed lines. , and the angle α of the objective lens 2 in the lens holder 1 supported by the first to fourth support wires 6 to 9 changes. In that case, the angle change of the printed circuit board 10 and the objective lens 2
is equal to the angle change, and since the rotational diameter of the first to fourth support wires 6 to 9 is larger than the rotational diameter of the objective lens 2, it is possible to finely adjust the attitude of the objective lens 2 in the tracking direction. Become. When the adjustment is completed, the screw 12 is tightly screwed into the frame 5 again. Thereby, the attitude of the objective lens 2 is maintained in an adjusted state.

(g) Effects of the invention As described above, according to the invention, the objective lens can be supported correctly. Furthermore, according to the present invention, when controlling the attitude of the objective lens, it is possible to control the jitter direction and the tracking direction independently, so adjustment for attitude control is easy and the lens holder can be adjusted. Support wires are used for support, so that there is no directionality in the direction perpendicular to the tensioning direction, so even if the objective lens is tilted to control its posture, the objective lens will not move in the tracking or focusing direction. It is possible to provide an optical pickup device that does not have any adverse effect on displacement. Furthermore, according to the present invention, the attitude of the objective lens in the tracking direction can be controlled simply by rotating the printed circuit board that fixes one end of the support wire, so there is no need for a special adjustment mechanism, and furthermore, fine adjustment is possible. It is possible to provide an optical pick-up device.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a cross-sectional view showing how the support wire is attached, and FIG. 3 is a model diagram for explaining attitude control of the objective lens. . Explanation of main drawing numbers, 1... Lens holder, 2...
...Objective lens, 3...Tracking coil, 4...
...Focusing coil, 5...Frame, 6,
7, 8, 9...support wire, 10...printed circuit board, 12...screw.

Claims (1)

[Scope of utility model registration request] In an optical pickup device having a lens holder with an objective lens attached thereto, in order to support the lens holder, four
A main support wire, a board to which one end of the four support wires is fixed, and a frame that is fastened to the frame so as to be fastened in the same direction as the axial direction of the four support wires with the board interposed therebetween. A fixing member that fixes the substrate to the frame by attaching the fixing member, and the substrate is rotatably supported with respect to the frame around the part that fixes the fixing member. type pick-up device.