JP2634546B2 - Optical means tilt adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device inclination adjusting device for adjusting the inclination of an optical device mounted on an optical disk device or the like.

[0002]

2. Description of the Related Art FIG. 11 is an exploded perspective view showing a conventional optical means inclination adjusting device described in Japanese Patent Application Laid-Open No. 59-223953, and FIG. 12 is a schematic sectional view thereof. 11 and 12, 1 is an objective lens, 2 is an objective lens driving device, 10 is a convex spherical surface formed on the bottom of the base of the objective lens driving device 2, 3 is an optical block, and 11 is an optical block 3. 4a, 4a, concave spherical surface formed or fixed on the upper surface of
b, 12a, 12b are coil springs, 5a, 5b, 5c,
5d is a screw hole, 6a, 6b, 6c and 6d are screws, 8 is an optical axis of the objective lens 1, and 9 is a focal point.

A convex spherical surface 10 is fitted into a concave spherical surface 11, and an objective lens driving device 2 is attached to the optical block 3 so as to be rotatable about the centers of the convex spherical surface 10 and the concave spherical surface 11. The coil springs 12a and 12b are compressed by screws 6c and 6d screwed into the screw holes 5c and 5d, and pull the objective lens driving device 2 toward the optical block 3 with a constant force.

Next, the operation will be described. Coil spring 4
a and 4b push up the objective lens driving device 2 and
And the spherical surface 11 move smoothly. Screw 6a,
Reference numeral 6b denotes a screw for adjusting the tilt of the objective lens. By turning these two screws, the tilt of the objective lens 1 integrated with the objective lens driving device 2 is adjusted.

[0005]

However, in the conventional optical device tilt adjusting device configured as described above, the tilt of the entire objective lens driving device is adjusted even though only the tilt of the objective lens is to be adjusted. Therefore, there is a problem in that the inclination adjusting device for the optical means is complicated and the number of parts is large, which is an obstacle to downsizing and thinning. In addition, there is another problem that the degree of freedom of design is greatly restricted by providing a spherical surface. Also, an adhesive is often used as a fixing method after adjusting the tilt angle, but the weight of the portion held by the adhesive is large, and the entire objective lens driving device vibrates when accessing the optical disc, and the tracking pull-in after the access is performed. , It takes a long time, so that the access time cannot be reduced.

The present invention has been made to solve such a problem, and the tilt of only the objective lens can be adjusted.
Moreover, it is an object of the present invention to provide an optical device inclination adjusting device having a simple configuration, a small number of components, and hardly causing unnecessary vibration during access.

[0007]

According to the present invention, there is provided an optical device inclination adjusting apparatus in which a ring-shaped flat plate is arranged between an optical unit such as an objective lens and a holder for holding the same, and one surface of the flat plate is arranged on the flat plate. to and between the holder in contact with the other surface of the flat plate of the optical unit in contact, first in street and twisted relationship with each other the optical axis, respectively, a plurality of protrusions across the optical axis to the second straight line It is provided.

A notch is provided in the holder, and the ring-shaped flat plate is fitted into the notch to form a circumferential portion.
The tongue is provided to restrict the rotation of the flat plate in the direction .

A notch is provided on the holder, and the flat plate is fitted in the notch on the flat plate in the circumferential direction.
The tongue that regulates the rotation of the
Tongue that fits into the opening and restricts rotation of the optical means in the circumferential direction
Each piece is provided.

[0010]

A pair of projections provided between the ring-shaped flat plate and the optical means have an end corresponding to the height of the projection about the first straight line connecting the projections with the tip as a fulcrum. Only, and a pair of protrusions provided between the ring-shaped flat plate and the holder can be tilted in one direction about a second straight line intersecting the first straight line as a rotation center. As a result, the tilt angles can be adjusted in two directions intersecting the optical means.

Further, since the tongue of the ring-shaped flat plate fits into the cutout portion of the holder, the ring-shaped flat plate does not rotate with respect to the holder, so that the tilt direction of one of the optical means does not change.

Further, since the tongue of the ring-shaped flat plate and the tongue of the optical means are fitted into the notch of the holder and do not rotate together, the two inclination directions of the optical means do not change.

[0013]

【Example】

Embodiment 1 FIG. FIG. 1 is an exploded perspective view of a main part of an optical means inclination adjusting device according to a first embodiment of the present invention, FIG. 2 is a perspective view of an objective lens driving device equipped with the optical means inclination adjusting device of FIG. 1, and FIG. 2 is a plan view of FIG. 2, FIG. 4 is a cross-sectional view of FIG. 3A-A, and FIG. 5 is a cross-sectional view of FIG. 3B-B.

In FIG. 1, reference numeral 20 denotes an objective lens, 21 denotes a ring-shaped flat plate (hereinafter, referred to as a “flat plate”), 22a and 2a.
Reference numeral 2b denotes a pair of upper projections provided on the flat plate 21 and provided on a first straight line L1 passing through the optical axis 8. 23a,
Reference numeral 23b denotes a pair of lower projections provided on the flat plate 21, and a second projection having a torsion relationship with the first straight line L1 through the optical axis 8.
On the straight line L2. 24 is an objective lens holder, 25 is a bearing, and 26 is a focusing coil.

2 to 5, reference numeral 100 denotes a base, which has a light beam passing hole 100a on a side surface so that a light beam 101 emitted from a light source (not shown) can be incident on the side surface. Reference numeral 102 denotes a focus base, which is a support shaft 1 coated with a fluorine resin having a small friction coefficient.
03 is held at the lower end. Numerals 104a and 104b denote focusing magnets magnetized in the vertical direction, which are fixed to the focus base 102 together with the focusing yokes 105a and 105b, and the focus base 102 is fixed to the base 100 by fixing screws 106a and 106b. Have been.

Reference numerals 107a and 107b denote tracking magnets magnetized in two poles in the left-right direction, and reference numeral 108 denotes a launch mirror that reflects the light beam 101 incident from the side vertically upward, and is bonded and fixed to the base 100, respectively. ing. 109 is a drive current application FPC, 110 is a photo interrupter, 111 is a photo interrupter 110
Are the photointerrupter fixing plates, and the driving current applying FPC 109 and the photointerrupter 110 are fixed to the base 100 by screws 113 and 114, respectively.

Reference numeral 24 denotes an objective lens holder formed of a lightweight, highly rigid plastic material or the like, so that a fin portion 24a protruding in parallel with the support shaft 103 is disposed in the gap of the photointerrupter 110. It is provided integrally with the objective lens holder 24. Reference numeral 20 denotes an objective lens fixed to one end of the objective lens holder 24 in the longitudinal direction, reference numeral 21 denotes a flat plate disposed between the objective lens holder 24 and the objective lens 20, and reference numeral 117 denotes an objective lens 20 in the longitudinal direction of the objective lens holder 24. The balance weight is fixed to one end that is not arranged.

Reference numeral 25 denotes a bearing fixed to the objective lens holder 24 so as to have an axis parallel to the optical axis of the objective lens 20, and is fitted to the support shaft 103.
Reference numeral 26 denotes a focusing coil fixed to the objective lens holder 24 so as to be coaxial with the bearing 25 so as to be disposed in a magnetic gap formed by the focus base 102 and the focusing yokes 105a and 105b. It is configured. Reference numeral 120 denotes a movable portion FPC fixed to the objective lens holder 24, which connects between the tracking coils 121a and 121b adhesively fixed to both side surfaces of the objective lens holder 24, as well as the focusing coil 26 and the tracking coil 12
It has a function of a relay board for supplying a drive current to the lead wires 1a and 121b through lead wires (not shown). The movable part 123 is configured by the above-described 24 to 121b . 1
24a to 124d are dampers, and the objective lens holder 2
4 and projections 125a and 125b provided on base 1
The movable portion 123 is slidably and rotatably supported on the support shaft 103 by being fixed to the pin portions 126a to 126d provided at 00. 127 is a cover, and the base 1
00 is fixed.

Next, the operation will be described. When performing the tilt adjustment of the objective lens 20 in the direction of arrow A shown in FIG. 1, the objective lens 20 is tilted in the direction of arrow A around the tips of the upper protrusions 22 a and 22 b provided on the flat plate 21. A desired force is applied to an appropriate point on the objective lens 20. When the inclination of the objective lens 20 in the direction of arrow B is adjusted, similarly, the objective lens 20 is tilted in the direction of arrow B around the tips of the lower protrusions 23a and 23b. Apply the desired force to the appropriate points.

The actual amount of tilt adjustment is 10 mrad (about 0.57 de) in a general optical disk device.
g) is often adjusted. When the outer diameter of the objective lens 20 is about 5 mm, the amount of protrusion of the pair of upper protrusions 22a and 22b and the pair of lower protrusions 23a and 23b necessary for performing the adjustment of 10 mrad is 25 μm.
m, which is a value that does not cause any problem in production.

After the tilt adjustment of the objective lens 20 is completed,
The flat plate 21 and the objective lens 20 are fixed to the objective lens holder 24 with an adhesive or the like.

The operation for driving the objective lens 20 is as follows.
When correcting the focus shift of the light spot (not shown) applies a desired current to the focusing coil 26, focusing magnet 104a, by an electromagnetic force obtained by the interaction of the magnetic force 104b occurs, the movable The unit 123 and, consequently, the objective lens 20 are driven and controlled in the direction of arrow C shown in FIG. 4 to control the focusing direction. When correcting a track deviation of a light spot (not shown), the tracking coil 121a,
The desired current is applied to 121b, tracking magnets 107a, by an electromagnetic force obtained by the interaction of the magnetic force 107b occurs, arrow direction showed movable portion 123 in FIG. 3 around the support shaft 103 toward To control the tracking direction of the objective lens 20.

Embodiment 2 FIG. FIG. 6 is an exploded perspective view of a main part of the second embodiment of the present invention, and two of the four projections for imparting an inclination angle to the objective
4 are provided as protrusions 24b and 24c, and the second embodiment can expect the same operation as the first embodiment.

Embodiment 3 FIG. FIG. 7 is an exploded perspective view of a main part of the third embodiment of the present invention. Of the four projections for giving an inclination angle to the objective lens 20, two are provided on the objective lens 20 as projections 20a and 20b. In the third embodiment,
The same operation as in the first embodiment can be expected.

Embodiment 4 FIG. FIG. 8 is an exploded perspective view of a main part of the fourth embodiment of the present invention. Of the four protrusions for imparting an inclination angle to the objective lens 20, two are formed on the objective lens 20 as protrusions 20a and 20b. The two are provided as projections 24b and 24c on the objective lens holder 24, and the fourth embodiment can expect the same operation as the first embodiment.

Embodiment 5 FIG. FIG. 9 is an exploded perspective view of a main part of a fifth embodiment of the present invention, in which a flat plate 21 is provided with a tongue piece 21a for restricting rotation in the in-plane direction, and the tongue piece 21a is fitted into the objective lens holder 24. This shows another embodiment in which the notch 24d is provided, and it is possible to limit the direction of adjusting the tilt angle of the objective lens 20.

Embodiment 6 FIG. FIG. 10 is an exploded perspective view of a main part of a sixth embodiment of the present invention, in which a flat plate 21 is provided with a tongue piece 21a for regulating in-plane rotation,
0, a tongue piece 20c for restricting rotation in the in-plane direction is provided so as to fit into a notch portion 24d provided in the objective lens holder 24, thereby limiting the direction of tilt angle adjustment of the objective lens 20. It is possible to do.

In each of the above embodiments, the case where the present invention is used for adjusting the inclination of the objective lens has been described. However, the present invention is also used for other lenses such as a collimator lens or for optical means such as a reflection mirror. It goes without saying that you can do it.

Further, in each of the above embodiments, the case where the present invention is used for adjusting the tilt of the objective lens alone has been described. However, the present invention includes the entire objective lens driving device or the objective lens driving device and the light source unit and the light detecting unit. Needless to say, it can be used for adjusting the tilt of the entire optical head device.

[0030]

Since the present invention is configured as described above, it has the following effects.

Since the component for adjusting the tilt can be constituted by only one thin ring-shaped flat plate, it is possible to obtain an inexpensive, small and thin optical device tilt adjusting device.

Further, since there is no need to provide a large spherical surface as in the conventional example, it is possible to greatly expand the degree of freedom in design.

Further, since the weight of the portion held by the adhesive is only the objective lens, the weight is light. Therefore, unnecessary vibration hardly occurs when accessing the optical disk, and the access time can be shortened.

Further, a notch and a tongue piece are provided so that the positions of the two pairs of projections do not change, and the straight lines connecting the respective pairs of projections are arranged substantially orthogonally.
By configuring the direction of each straight line to correspond to the radial direction and the tangential direction of the optical disk, it is possible to define the tilt direction of the optical unit and to easily adjust the tilt.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a main part of an optical device inclination adjusting device according to a first embodiment of the present invention.

FIG. 2 is a perspective view of an objective lens driving device equipped with the optical unit inclination adjusting device of FIG. 1;

FIG. 3 is a plan view of an objective lens driving device equipped with the optical unit inclination adjusting device of FIG. 1;

4 is a cross-sectional view of the objective lens driving device equipped with the optical unit inclination adjusting device of FIG.

FIG. 5 is a cross-sectional view of the objective lens driving device equipped with the optical unit inclination adjusting device of FIG.

FIG. 6 is an exploded perspective view of a main part of an optical unit inclination adjusting apparatus showing Embodiment 2 of the present invention.

FIG. 7 is an exploded perspective view of a main part of an optical unit inclination adjusting apparatus showing Embodiment 3 of the present invention.

FIG. 8 is an exploded perspective view of a main part of an optical unit inclination adjusting device showing Embodiment 4 of the present invention.

FIG. 9 is an exploded perspective view of a main part of an optical unit inclination adjusting apparatus showing Embodiment 5 of the present invention.

FIG. 10 is an exploded perspective view of a main part of an optical unit inclination adjusting apparatus showing Embodiment 6 of the present invention.

FIG. 11 is an exploded perspective view showing a conventional optical unit inclination adjusting device.

FIG. 12 is a schematic cross-sectional view showing a conventional optical unit inclination adjusting device.

[Explanation of symbols]

 8 Optical axis 20 Objective lens 20a Projection 20b Projection 20c Tongue 21 Ring-shaped flat plate 21a Tongue 22a Upper projection 22b Upper projection 23a Lower projection 23b Lower projection 24 Objective lens holder 24a Fin 24b Projection 24c Projection 24d Notch 25 Bearing 26 Focusing coil L1 First straight line L2 Second straight line

Claims (3)

(57) [Claims] 1. A contact to the optical unit inclination adjustment device for angular Docho integer in the desired direction of the optical axis of the optical science means that is held in the holder
There are, distributing the-rings flat plate between said optical means and the holder
And passes through the optical axis in one plane of the flat plate and
On a first straight line perpendicular to the optical axis and the other of the flat plates
Of the first straight line passing through the optical axis in the plane of
The optical axis is placed on each of the second straight lines in the relationship.
Nde optical means inclination adjustment device, characterized in that digits setting a plurality of projections. 2. The method of claim 1, provided with a cutout portion in the holder, in the cutout portion in the flat plate
An inclination adjusting device for optical means, comprising a tongue which is fitted to regulate rotation of a flat plate in a circumferential direction. 3. The method of claim 1, provided with a cutout portion in the holder, in the cutout portion in the flat plate
The tongue fitted to restrict the rotation of the plate in the circumferential direction, the
The optical means is fitted in the notch and the optical
An optical device inclination adjusting device, wherein a tongue piece for restricting rotation of the device is provided.