JPS6236747A - Positioning mechanism for attachment member of optical pickup device - Google Patents

Abstract

PURPOSE:To secure the effect equivalent to the combination of a round pin and a slender hole and to simplify comparatively the working, by having a round form and an oval having a larger length in the direction orthogonal to the straight line connecting two feet or a diamond form for the sections orthogonal to the axes of said two feet which are fitted to two round holes respectively. CONSTITUTION:A collimator lens 5 is supported by a collimator lens holder 5a having two feet 5b and 5c on its back side. Both feets 5b and 5c are fitted to the positioning round holes 1i of a body 1 respectively. For the sections orthogonal to the axes of both feet 5b and 5c, the foot 5b has a round form and the foot 5c has an oval form having the larger length toward the optical axis and the shorter length in the direction orthogonal to the optical axis or a diamond form respectively. Thus the foot 5c can move slightly in the direction orthogonal to the optical axis within the hole 1i. As a result, a dimensional error is allowed to some extent (between the spaces of feet and round holes) in the direction orthogonal to the optical axis with the high positioning accuracy kept in the direction of the optical axis.

Description

[Detailed description of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting plate positioning mechanism for an optical pickup device used in a video disc player, a compact disc player, etc. (Summary of the Invention) A body is provided with two round holes for positioning, a member attached to the body is provided with two protruding legs that fit into the two round holes, and the two legs The shape of the cross section perpendicular to the axis of This is a mounting member positioning mechanism in an optical pickup device that allows dimensional errors between the leg spacing and the round hole spacing to a certain extent while maintaining high directional positioning accuracy.

[Conventional technology]

Conventionally, in order to accurately position the mounting member in an optical pickup device, two legs consisting of a round bottle protruding from the mounting member are connected to a round hole in the body (a straight line connecting the two legs). This allows the ax to be fitted into the elongated holes (long in the direction of There are known devices that allow it by letting it escape. However, such a device has the disadvantage that processing to space the long holes with high dimensional accuracy is technically quite difficult. [Problems to be Solved by the Invention] The purpose of the present invention is to improve the above-mentioned drawbacks of the conventional 1iKl. An object of the present invention is to provide a mounting member positioning mechanism for an optical pickup device. Means for Solving Problem K] In order to achieve the above object, the attachment member positioning mechanism of the optical pickup [IF of the present invention] has two round holes for positioning provided in the body and a two legs protruding from the member to be attached and fitted into the two round holes, and one of the two legs has a cross section perpendicular to the axis, one of which is circular; The other side is shaped like an ellipse or a diamond, which is long in the direction perpendicular to the straight line connecting the two legs. K effect 1 By doing this, the leg with an elliptical or diamond-shaped cross section can move a little inside the hole in the direction of the straight line connecting the two legs, so the positioning accuracy in the direction perpendicular to it can be improved. It absorbs the dimensional error between the distance between the two legs and the distance between the round holes to a certain extent while keeping the distance high, and it is much easier to process the outer shape into an oval or diamond shape compared to the long holes of conventional machines. can be done. K Embodiment] An optical pickup device which is an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view and a front view thereof, and FIG.
The figure is a plan view (partial view) showing the state where the base 10 in which the actuator 9 is integrated is removed. The optical pickup device includes a laser diode 2, a grating 3, and a plate prism 4 built into a body 1.
, a collimator lens 5, a triangular prism 6, a multi-lens 7, a photodetector 8, and an actuator 9 built into a base 10. FIG. 3 is an explanatory diagram showing the optical path. In order to display on the same plane, the triangular prism 6, objective lens 9a, and disk D are arranged at 90 degrees centering on the optical axis in the left and right direction in the figure.
The laser beam emitted from the laser diode 2 is reflected by the plate prism 4 and the triangular prism 6, focused by the objective lens 9a, and is focused on the disk D located above the optical pickup device. The reflected light that is converged on the signal recording surface and modulated by the recording signal is reflected again by the triangular prism 6, passes through the plate prism 4 and the multi-lens 7, is given astigmatism, and is guided to the photodetector 8. The plate prism 4 has a half mirror 4a made of a thin gold film formed on one side of a glass plate with parallel planes.
The laser beam emitted from the laser diode 2, which is arranged at an angle of about 45 degrees with respect to the optical axis, is reflected by this half mirror 4a toward the triangular prism 6, and conversely, it is sent from the triangular prism 6 to the disc. The reflected light (modulated by the signal recording surface of D) passes through the plate prism 4 and is sent to the multi-lens 7. The reflected light from the signal recording surface of the disk D passes through the plate prism 4.
Astigmatism is applied when passing through the light. The multi-lens 7 is a combination of a concave lens and a cylinder lens, and provides astigmatism (in a direction different from that of the plate prism 4) to transmitted light, as well as (by moving its position in the optical axis direction). Change the convergence position of transmitted light. The photodetector 8 is composed of a focus detector consisting of four photodetecting elements divided by two orthogonal straight lines and a pair of tracking detectors placed on both sides of the focus detector, and the detection signals of these rain detectors are detected by the objective lens. The signal 9a is input to the actuator 9 as a drive control signal. The direction in which astigmatism, which is the combination of astigmatism given by the plate prism 4 and the multi-lens 7, occurs is set so that it faces the direction in which the sensitivity of the focus detector of the photodetector 8 is maximum, and To eliminate the influence of recording track shadows on focus detection,
The direction of the recording track is set to match the direction of one dividing line of the focus detector. By adjusting the position of the multi-lens 7 in the optical axis direction and in the plane orthogonal to the optical axis so that the light beam transmitted through the plate prism 4 enters the photodetector 8 correctly (with the photodetector 8 fixed), the light is It is designed to perform axis alignment and focus adjustment. FIG. 4 shows a support structure for the multi-lens 7, in which the multi-lens 7 is fixed within a lens sleeve 7b having a diameter of 18 mm in the circumferential direction.
is supported in a lens base 7d having a pair of internal parts 7C so as to be slidable in its axial direction but not rotated. As shown in FIG. 2, the lens base 7d has its pair of wing parts 7C held between the positioning part 1a of the body 1 and the elastic base presser 1b, and is thereby moved in a plane perpendicular to the optical axis. Possibly supported. The tips of the wing ICs of the lens base 7d face windows 1C formed on both sides of the body 1, and when aligning the optical axis, use a jig to open the wing parts 7C from the windows 1C. Position WI adjustment is performed within a plane perpendicular to the clamping optical axis. Further, when adjusting the focus, an eccentric bottle is inserted through a hole formed on the back surface of the body 1 and the lens base 7d, and the eccentric bottle is engaged with the groove 18 of the lens sleeve 7b and rotated. Adjustment is made by changing the position of the lens sleeve 7b in the optical axis direction. The plate prism 4 is adhesively fixed to the positioning portion 1d of the body 1 on the surface on which the half mirror 4a is provided, and is also fixed at a small interval on both ends of the plate prism 4 and on the surface opposite to the half mirror 4a. Four protrusions 11a are arranged to prevent movement. These four protrusions 11a are provided on the back cover 11, as shown in FIG.
Used for temporary positioning when installing. As shown in FIG. 2, a G holder 38 that supports the grating 3 and the laser diode 2 are installed in an attachment hole 1e formed in a protrusion on the side surface of the body 1. The G holder 3a is positioned by bringing its front surface into contact with the first step 1'' in the mounting hole 1e, and the G holder 3a is positioned between the rear surface and the base of the laser diode 2.
It is pressed forward by a spring 3b and supported so as to be rotatable and adjustable around the optical axis. Laser diode 2 attaches the shoulder of its base to mounting hole 1.
It is positioned by coming into contact with the second step 1g in e, and its rear surface is pressed and supported by the LD presser 12. The LD presser 12 has two elastic legs each having an engaging claw 12a at the tip thereof. are engaged with the engaging portions 1h, respectively. When installing the G holder 3a and the laser diode 2, insert the G holder 3a1 washer, G spring 3b, and laser diode 2 into the mounting hole 1e in this order, and place the LD holder 12 on the rear surface of the base of the laser diode 2. The engaging claws 1 of the two elastic legs are brought into contact and pressed.
2a are respectively engaged with the engaging portions 111 of the body 1 by the elasticity of the elastic legs. The laser diode 2 is very susceptible to static electricity and easily damaged, but if it breaks, remove the engaging claw 12a of the LD presser 12 from the engaging portion 1h of the body 1 and remove the LD presser 12 (or Easy Laser Diode 2
can be replaced individually. The collimator lens 5 is supported by a collimator holder 5a having two legs 1l15b and 5C on the back surface, and its two legs 5b and 5C are inserted into the positioning round hole 11 of the body 1, as shown in FIG. They are fitted together. The shape of the cross section perpendicular to the axis of the two legs 5b and 5C is
One leg 5b has a circular shape, and the other leg 5C has an elliptical or diamond shape that is long in the direction of the optical axis and short in the direction orthogonal to the optical axis, and the leg 5C is shaped like an optical axis within the round hole 11. It can be moved slightly in the orthogonal direction, thereby allowing a certain degree of dimensional error (between the distance between the legs and the distance between the round holes in the direction perpendicular to the optical axis) while maintaining high positioning accuracy in the direction of the optical axis. It looks like this. FIG. 7 is an exploded perspective view of the objective lens 9a@actuator 9 which is swingably supported and performs focus control and tracking control. The actuator 9 is integrated into the base 10, and when the base 10 is attached to the body 1, the objective lens 9a is positioned above the triangular prism 6. The positioning of the base 10 with respect to the body 1 is similar to the positioning of the collimator holder 5a shown in FIG. 6, by fitting the round bottle J3 and the diamond bottle protruding from the base 10 into the round holes provided in the pickup body, respectively. It is done by method. The actuator 9 includes a flange 9d to which an objective lens 9a, a focus coil 9b, and two tracking coils 9C are fixed, and a projection 10 of a base 10 that connects the flange 9d.
It is comprised of two sets of suspension springs 9e and 9f on each of the left and right sides that are swingably supported on the base 10, a magnet 9g fixed to the base 10, and a yoke 9h. The magnet 9g has a trapezoidal shape in which the width on the side facing the coil is wider than that on the opposite side, so that the magnet 9g has a trapezoidal shape that is wider on the side facing the coil than on the opposite side. 7 lunge 9d (for tracking) when the outer corner of the magnet side of the pickup P is cut diagonally (to avoid hitting the wall of the CD player)
Both tracking coils 9c remain intact even if there is a large vibration left or right.
(The straight part on the inside of the J) is shaped like a sea urchin so that it does not come off the surface of the magnet 9g. Note that it is sufficient that the magnet 9g has a shape in which at least the corners on the outer circumferential side are shaved, so the shape is not limited to an isosceles trapezoid, but may also be an isosceles trapezoid in which the outer circumferential side is more inclined than the inner circumferential side. Needless to say, it's a good thing. In order to keep the attitude of the objective lens 9a parallel to the optical axis when driving the objective lens 9a to perform focus control and tracking control, the flanges 9d are arranged in parallel with each other at intervals vertically on both the left and right sides of the flanges 9d. It is supported by two sets of suspension springs 9e and 9f. There are a total of 4 sets of suspension springs 9e and 9'' on the left and right sides.
As shown in FIG. 9, the flange 9 has a shape in which mounting terminals 9j are provided at both ends of two elongated elastic plate-shaped conductors 91 arranged in parallel.
d and also serves as a lead wire for sending control signals to the focus coil 9b and the tracking coil 9C. As shown in the figure, the upper and lower suspension springs 9e and 9f on one side are integrally manufactured in a shape in which the terminals 9j on both sides thereof are connected by two claw portions 9k through narrow connection portions. When installing, the terminals 9j on both sides are adhesively fixed to the protrusion 10a and flange 9d of the base 10, respectively, and the two claws 9k are broken off to electrically separate the upper and lower springs (9e and 9f, etc.). This facilitates the gluing work and allows the upper and lower suspension springs 9e and 9'' to be attached accurately in parallel. The two plate-shaped conductors 91 forming each suspension spring 9e and 9f have different widths (for example, 0
．． 10IllIIl and 0.12mm) Due to the different resonance frequencies, suspension springs 9e and 9f are less likely to resonate at a specific frequency, thereby making it less likely that unnecessary resonance will occur. In addition, in this case, it seems that placing the wider plate-shaped conductor 91 on the outside (that is, on the upper side in 9e and on the lower side in 9f) will have a more pronounced effect. It is. Furthermore, a dance material 9III made of a viscoelastic material such as butyl rubber or silicone rubber is filled between the two plate-shaped conductors 91 of the suspension springs 9e and 9f, thereby damping the resonance generated in the plate-shaped conductor 91. It looks like this. The manufacturing process of the suspension spring will now be described with reference to FIGS. 10 and 11. A large number of suspension springs 9e and 9f are simultaneously formed on one sheet 13 by etching, with the periphery connected at only the @ locations so that they can be easily separated. After thoroughly washing this sheet 13, ■ apply a brimer, and as shown in FIG. ■Temperature 2
Vulcanize at 00°C for 15 minutes and bake 9 m of dump material. 9m of dump material is coated with primer as a pre-treatment.
This is to make it easier to adhere. Dump material 9m with silk screen mark @1ffit4
When applying, a printing brush is moved in the longitudinal direction of the plate-shaped conductor 91. In addition, if scaly particles 9n (for example, scaly graphite, mica, etc.) with a size of several μm to several tens of μm are mixed into the dump material 9m, the two plate-like conductors 91
The effect of the so-called book damper becomes stronger, and the ``braking'' effect becomes larger. Furthermore, by using silk screen printing,
As shown in FIG. 12, the scale-like particles 9n are distributed in the moving direction of the printing brush (that is, in the longitudinal direction of the plate-shaped conductor 91).
Since they are aligned facing the same direction, the "shear damping" effect becomes even greater. In addition, in the above embodiment, each suspension spring 9e
Although the number of plate-like conductors 91 constituting ``and 9'' is two, it is not limited to this and may be three or more. The attachment member positioning mechanism for an optical pickup device of the present invention includes two round holes for positioning provided on a body, and a member attached to the body that protrudes from the body and fits into the two round holes, respectively. The shape of the cross section perpendicular to the axis of the two legs is circular, and the other is oval or long in the direction perpendicular to the straight line connecting the two legs. By making each leg into a diamond shape, it is possible to maintain a high positioning t of 11 degrees in the direction perpendicular to the straight line connecting the two legs, while allowing for the difference in dimension W4 between the leg spacing and the round hole spacing to a certain extent. Furthermore, machining of legs having an oval or rhombic outer shape is much easier than machining of long holes in conventional devices.

[Brief explanation of the drawing]

Fig. 1: A plan view and front view of an embodiment of the invention Fig. 2: A plan view with the cover removed Fig. 3:
...Explanatory diagram showing the optical path Fig. 4...A perspective view without showing the support mechanism of the multi-lens Fig. 5...A perspective view of the back cover Fig. 6...Showing the collimator lens positioning means Explanatory diagram: Figure 7: Disassembled perspective view of the actuator: Figure 8:
・・Plan view showing its arrangement in a CD player FIG. 9 ・Plan view of the suspension spring FIG. 10 ・・Plan view of one manufacturing process of the suspension spring FIG. 11 ・・Silk screen of the suspension spring Side view showing printing FIG. 12...Explanatory diagram of the damping agent of the suspension spring 11...Round hole 5a...Collimator holder 5b, 5c...
Leg 10...Base

Claims (1)

[Claims] Consisting of two round holes for positioning provided on the body, and two legs protruding from a member attached to the body and fitted into the two round holes, respectively, the two legs An optical pickup characterized in that the shape of the cross section perpendicular to the axis of the optical pickup is circular on one side, and elliptical or diamond-shaped long in the direction perpendicular to the straight line connecting the two legs. A mechanism for positioning attachment members in a device.