JPH06195722A - Optical head moving mechanism - Google Patents

Abstract

PURPOSE:To embody a thinner and lighter type device and to provide a fine adjustment for an angle of inclination and accurate movement. CONSTITUTION:A shape like a substantially square pillar is made with a long hollow in the direction X, and a carriage 19 for slidably inserting a guide shaft 3a into the hollow is provided with a cylinderic shaft 19a having a groove 19b in one-side surface and is provided on the other end side with a hood having a screw hole 19c made. In one-side of a base 11, a hole 2a is provided in the direction Y vertically crossing the optical axis of an objective lens 12 and the shaft part 19a is inserted into the hole 2a. Further, the base 11 is provided with a notch like a rectangular parallelopiped in the position corresponding to the hood 19d, and a hole 2e is made in the bottom thereof. A screw 17 used for adjusting an angle of inclination is inserted into the hole 2e from the lower side and a compressing coil spring 16 is fitted to the screw 17 used for adjusting an angle of inclination from the upper side, and futher the screw 17 used for adjusting an angle of inclination is screwed into a screw 19c. Thereby, the angle of inclination of an optical head part 2 in the direction of thetay is adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical head transfer mechanism having an optical head tilt adjustment mechanism in an optical disk device for optically recording or reproducing information.

[0002]

2. Description of the Related Art FIG. 10 is an exploded perspective view showing a conventional optical head transfer mechanism. Reference numeral 1 in the drawing denotes a carriage for moving the optical head unit 2 along two parallel guide shafts 3a, 3b extending in the radial direction (X direction in the drawing) of the optical disk 18. The carriage 1 is provided with fixing members 1a and 1b for fixing the optical head portion 2 on one side of a plate portion 1d larger than the optical head portion 2 at a distance corresponding to the width of the optical head portion 2. The fixing members 1a and 1b are both in the shape of a truncated quadrangular pyramid, and they are juxtaposed in the tangential direction (Y direction in the drawing) of the optical disc 18, and the spring pins 14a and 14b.
Holes 15a and 15b penetrating in the Y direction for inserting the holes are formed.

A cylindrical portion 1c for slidably inserting the guide shaft 3a is attached to the outside of the fixing member 1a with the longitudinal direction thereof being the X direction. Further, an eccentric pin fixing member 1f having substantially the same form as the fixing member 1b is attached side by side with the fixing member 1b in the X direction.
In 1f, two through holes 81, 81 penetrating in the Y direction are arranged side by side in the vertical direction (Z direction) in the figure at a predetermined distance, and these through holes are formed from one side surface in the X direction. Two holes 82, 82 reaching 81, 81 have been opened.

The optical head unit 2 has an objective lens 12 for collecting and irradiating a light beam perpendicularly to the surface of the optical disc 18.
Is provided in a portion of the upper surface of the base 11 having a substantially rectangular parallelepiped shape, the central portion in the width direction being opened. The side surface of the base 11 is provided with a hole 13a at a position corresponding to the hole 15a and a hole (not shown) at a position corresponding to the hole 15b. By mounting the optical head portion 2 on the carriage 1 and inserting the spring pins 14a and 14b into the hole 13a and the hole (not shown) through the holes 15a and 15b, the optical head portion 2 is rotated about the Y axis. It can be supported rotatably in the moving direction (radial tilt direction; θy direction). Board part 1d
A hole 1e is opened on the other side, and a tilt adjusting screw 17 is screwed into the hole 1e from below, and a compression coil spring 16 is fitted into the tilt adjusting screw 17 from above the plate portion 1d. . Then, the tilt angle adjusting screw 17 is rotated to change the tip position of the tilt angle adjusting screw 17 in contact with the optical head unit 2, thereby adjusting the tilt angle of the optical head unit 2 in the θy direction.

A spring 5 is fitted on the guide shaft 3a, and linear ball bearings 4a and 4b are further fitted from the outside thereof.
Are fitted. Then, in this state, it is inserted into the hollow portion of the carriage 19, and both sides are C-rings to define the positions of the linear ball bearings 4a and 4b in the carriage 19.
It is fitted with 6a and 6b. As a result, the carriage 19 can be moved along the guide shaft 3a.

The eccentric pins 8a and 8b, which are integrally provided with shafts having different axes, are inserted into the through holes 81 and 81, respectively.
The other shaft part is exposed to the side (outside) on which the optical head part 2 is not placed. Radial ball bearings 7 are attached to the other shafts, respectively.
a, 7b are fitted together, these radial ball bearings 7a,
The eccentric pins 8a and 8b are pressed against the 7b by fitting retaining rings 9a and 9b. A negative groove (not shown) is formed in the head of the other shaft of the eccentric pin 8a, and the carriage 1 is rotated by rotating the eccentric pins 8a and 8b with a flat head screwdriver.
By changing the relative height between the guide shaft 3b and the guide shaft 3b, a direction around the X axis of the optical head unit 2 (a tangential tilt angle direction;
The tilt angle in the θx direction) can be adjusted. Further, by screwing the screws 10a and 10b into the holes 82 and 82, the eccentric pins 8a and 8b can be fixed.

Here, the distance between the radial ball bearings 7a and 7b corresponds to the diameter of the guide shaft 3b, the guide shaft 3b is clamped by the radial ball bearings 7a and 7b, and the carriage 1 is moved along the guide shaft 3b. It is possible. The lower eccentric pin 8b has a larger eccentric weight than the upper eccentric pin 8a.

Next, a method of adjusting the tilt angle of the optical head portion 2 will be described. First, by rotating the tilt adjusting screw 17, the optical head part 2 is rotated with respect to the carriage 1 about the spring pins 14a and 14b, and the radial tilt direction (θ
Fine adjustment in y direction). On the other hand, eccentric pins 8a, 8b
By rotating, the fine adjustment is performed in the tangential tilt angle direction (θx direction) of the entire carriage 1. After that, by tightening the screws 10a and 10b, the optical head unit 2
Is fixed at the required tangential tilt angle.

As described above, in the conventional optical head transfer mechanism, by using the two linear ball bearings 4a and 4b and the two radial ball bearings 7a and 7b,
The optical head unit 2 can be smoothly moved along the two parallel guide axes 3a and 3b in the radial direction (X direction) of the optical disc 18 at an appropriate inclination angle. Further, the eccentric pin 8b is appropriately rotated to sandwich the guide shaft 3b between the radial ball bearings 7b, so that the carriage 1 can be stably moved. The optical head unit 2 can also be used in a vertical position.

[0010]

However, in the conventional optical head transfer mechanism, since the carriage 1 is arranged below the optical head portion 2, in addition to the thickness of the optical head portion 2, the thickness of the carriage 1 and A space for operating the tilt adjusting screw 17 is required, which is inconvenient for thinning and weight reduction. Further, since the guide shaft 3b is sandwiched by the radial ball bearings 7a and 7b whose intervals are fixed by screwing, the dimensional accuracy and arrangement accuracy of the guide shaft 3b are directly dependent on the optical head unit 2.
However, there is a problem in that the sliding characteristics of the carriage 1 are significantly affected. The present invention has been made in view of such circumstances, and by arranging the carriage on the side of the optical head unit and reducing the space for adjusting the tilt angle, thinning and weight reduction are realized, and An object of the present invention is to provide an optical head transfer mechanism that can perform fine adjustment of the tilt angle of the optical head part and transfer in the radial direction with high accuracy.

[0011]

According to a first aspect of the present invention, there is provided an optical head transporting mechanism, wherein a carriage having an edge portion protruding toward the optical head portion is provided on one side surface of the optical head portion, and an edge portion provided on the carriage. And the bottom of the optical head section are screwed together to adjust the tilt angle about the tangential direction of the optical disk. Further, a hole is provided on the other side surface of the optical head section, and an eccentric pin is provided in this hole. By mounting and rotating this eccentric pin, the tilt angle of the optical head unit about the other guide shaft is adjusted.

The optical head transfer mechanism according to the second invention is the first
In the invention, a bearing holder is provided, which is rotatably fitted to an eccentric pin and in which a pin to which a second rolling element is fitted is erected, and the bearing holder is provided by the second rolling element and the first rolling element. It is characterized in that one guide shaft is sandwiched.

[0013]

According to the first aspect of the present invention, the carriage is arranged on the side of the optical head portion to realize a thin structure. Further, since the fine adjustment in the radial tilt direction of the optical head portion is performed by screwing the edge portion provided on the carriage and the bottom portion of the optical head portion, it is possible to reduce the space required for the adjustment as compared with the conventional case. .

According to the second invention, in addition to the above effects,
One of the guide shafts is sandwiched by the first rolling body having the fixed rotation shaft and the second rolling body having the rotation shaft rotatable about the rotation shaft. It is possible to reduce the influence of accuracy and placement accuracy on sliding characteristics.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments. FIG. 1 is an exploded perspective view showing a first embodiment of an optical head transfer mechanism according to the present invention, FIG. 2 is this perspective view, and FIG. 3 is a front view. Further, FIG. 4 is a side view of the optical head portion. In the figure, 18 is an optical disc,
2 is an optical head unit. Two guide shafts 3 parallel to each other in the radial direction (X direction in the figure) of the optical disk 18
A and 3b are extended, and the optical head unit 2 is moved in the radial direction of the optical disc 18 along the guide shafts 3a and 3b.

The optical head unit 2 has an objective lens 12 for collecting and irradiating a light beam perpendicularly to the surface of the optical disk 18.
Is provided in a portion of the upper surface of the base 11 having a substantially rectangular parallelepiped shape, the central portion in the width direction being opened. On one side surface of the base 11, there is provided a hole 2a for mounting the carriage 19 in the tangential direction (Y direction) of the optical disk 18 which intersects the optical axis of the objective lens 12 perpendicularly. hole
A hole 2c reaching 2a is provided in the vertical direction (Z direction).

On the other hand, the carriage 19 is in the shape of a hollow prism having a long shape in the X direction. The spring 5 is fitted in the hollow portion, and the linear ball bearing is attached from the outside.
The guide shaft 3a in which the 4a and 4b are fitted is slidably inserted.
And the linear ball bearing in the carriage 19
C-rings 6a and 6b are fitted on both sides to define the positions of 4a and 4b. This causes the carriage 19 to move to the guide shaft 3a.
Can be transported along.

A columnar shaft portion 19 provided with a groove 19b at a position corresponding to the hole 2a on one side surface of the carriage 19.
with a. On the other end side that does not have this shaft portion 19a, a side portion 19d with a screw hole 19c opened from the upper surface toward the base 11.
Is provided. By fitting the shaft portion 19a into the hole 2a, the base 11 can be rotatably supported in the rotation direction about the Y axis (radial tilt angle direction; θy direction). When the set screw 20 is further screwed into the hole 2c, the set screw 20 is caught in the groove 19b of the shaft portion 19a, and the shaft portion 19a can be prevented from coming off.

The base 11 is provided with a rectangular parallelepiped notch at a position corresponding to the ridge 19d, and a hole 2e is opened at a position corresponding to the screw hole 19c at the bottom thereof. Then, the tilt adjusting screw 17 is inserted into the hole 2e from below, the compression coil spring 16 is fitted from above, and the tilt adjusting screw 17 is screwed into the screw hole 19c.
The tilt angle is adjusted.

As shown in FIG. 4, the side surface of the base 11 facing the one side surface is provided with a hole 2b for inserting an eccentric pin 8a integrally provided with a shaft portion having a different axis. Further, a screw hole 2d reaching the hole 2b in the X direction is provided. One shaft part of the eccentric pin 8a is inserted into the hole 2b, a radial ball bearing 7a is fitted to the other shaft part, and this radial ball bearing 7a is compressed by fitting the retaining ring 9a to the eccentric pin 8a. To do. A negative groove (not shown) is machined on the head of the other shaft of the eccentric pin 8a. By rotating the eccentric pin 8a with a flat head screwdriver, the base 11 is moved in the tangential tilt direction (θx direction).
It is possible to fine-tune to. Then, by screwing the eccentric pin 8a with the screw 21, if necessary, the eccentric pin 8a
It is designed to prevent the rotation of the.

Next, a method of adjusting the tilt angle of the optical head portion 2 will be described. First, by rotating the tilt angle adjusting screw 17, the optical head unit 2 is rotated about the shaft portion 19a of the carriage 19 to perform fine adjustment in the radial tilt angle direction (θy direction). Here, by tightening the set screw 20, the rotation of the carriage 19 is suppressed as necessary.

On the other hand, with the radial ball bearing 7a engaged with the guide shaft 3b, that is, with the height of the other shaft portion of the eccentric pin 8a kept constant, the eccentric pin 8a is rotated by a flat-blade screwdriver. As a result, the relative height of the one shaft portion with respect to the other shaft portion of the eccentric pin 8a is changed, whereby one side portion of the optical head portion 2 (base 11) into which the one shaft portion is inserted and the other shaft portion are fitted. The relative height of the radial ball bearing 7a and the guide shaft 3b on which the radial ball bearing 7a moves changes. At this time, since the height of the other side portion of the optical head portion 2 (base 11) to which the carriage 19 is attached is fixed, if the height of one side portion of the optical head portion 2 (base 11) is changed. The entire optical head unit 2 can be rotated in the tangential tilt angle direction (θx direction). In this way, the optical head section 2 is finely adjusted in the θx direction, and then the set screw 21 is tightened to fix the optical head section 2 at a required inclination angle.

As described above, the optical head unit 2 can be fixed by adjusting the tilt angle independently in the radial tilt direction and the tangential tilt direction. Furthermore, the two linear ball bearings 4a and 4b and the one radial ball bearing 7a enable smooth movement along the two parallel guide shafts 3a and 3b. Moreover, the space required in the thickness direction (Z direction) is significantly reduced as compared with the conventional one.

FIG. 5 is an exploded perspective view showing a second embodiment of the device of the present invention, and FIG. 6 is a side view thereof. In the above-described first embodiment, the guide shaft 3b has one radial ball bearing.
In the second embodiment, the guide shaft 3b is supported by two radial ball bearings 7a, 7b which are automatically sandwiched by an appropriate force.

As in the first embodiment, the base 11 has an eccentric pin.
The uniaxial portion of 8a is fitted. Further, a pin 23 is provided so as to penetrate the oval bearing holder 22 in a direction of the major axis in a direction perpendicular to the bearing holder 22, and has a hole in the other end. By inserting the other shaft portion of the eccentric pin 8a into this hole, the bearing holder 22 is attached so as to be rotatable around the other shaft portion of the eccentric pin 8a.

A tension spring 24 is attached to a portion of the pin 23 inside the bearing holder 22 (on the side of the base 11), and the other end of the tension spring 24 is fixed to the base 11 with a screw 25. The mounting position of the screw 25 is provided at a position equal to or higher than the guide shaft 3b so that the guide shaft 3b can be sandwiched by the radial ball bearings 7a and 7b. Also, the strength of the tension spring 24 is determined by the radial ball bearing 7a and the radial ball bearing 7b.
When and are in contact with the guide shaft 3b, they are set to values such that the guide shaft 3b can be sandwiched with a required force.

On the other shaft of the eccentric pin 8a, a spring ring 22a and a radial ball bearing 7a are further fitted to the outside of the bearing holder 22, and a retaining ring 9a is fitted to the spring ring 22a and the radial ball bearing. Holds 7a. A radial ball bearing 7b is also fitted to the outside of the pin 23 and is held by a retaining ring 9b. The distance between the radial ball bearings 7a and 7b is set to be slightly larger than the diameter of the guide shaft 3b. Other configurations are first
It is similar to the embodiment.

In the second embodiment, the radial ball bearing 7b is arranged so as to be located below the guide shaft 3b during assembly as shown in FIG. Then, the pin 23 is pulled by the force of the tension spring 24, the bearing holder 22 rotates about the other shaft of the eccentric pin 8a, and the radial ball bearing 7b moves to the fixed position side of the screw 25, which causes the radial ball to move. The bearing 7b sandwiches the guide shaft 3b.

Fine adjustment of the optical head section 2 in the second embodiment in the radial tilt direction and the tangential tilt direction can be performed by the same method as in the first embodiment. Further, the guide shaft 3a is supported by two linear ball bearings 4a and 4b, and the guide shaft 3b includes a radial ball bearing 7a having a fixed rotation shaft and a radial ball bearing 7b having a rotation shaft moved by a spring force. The optical head unit 2 can be stably transferred in the radial direction of the optical disc 18 by being sandwiched by In addition, since the guide shaft 3b is clamped with the required force, it can be used in a vertical position and the like, and the guide shaft due to vibration and impact can be used.
It is possible to prevent the separation of 3b.

FIG. 7 is an exploded perspective view showing a third embodiment of the device of the present invention. In the first and second embodiments described above, the radial ball bearing and the linear ball bearing are used to transfer along the guide shaft, but in the third embodiment, four outer groove bearings are used. , Guide shaft 3a,
The optical disk is moved in the radial direction by engaging the grooves of these bearings with external grooves with 3b.

In the figure, reference numeral 30 denotes a substantially L-shaped carriage having a longer bottom portion when viewed from the front (side surface viewed from the X direction), and the vertical portion 301 has a shaft portion 30a fitted into the hole 2a. Further, a ridge portion 30i having a screw hole 30b is provided toward the base 11 side above the vertical portion 301 at a position corresponding to the hole 2e. By fitting the shaft portion 30a into the hole 2a, the base 11 can be rotatably supported in the θy direction. Then, insert the tilt adjustment screw 17 into the hole 2e from below, fit the compression coil spring 16 from above, and
The inclination angle adjusting screw 17 is screwed into 30b to adjust the inclination angle of the optical head portion 2 in the θy direction, and the rotation is suppressed by screwing the set screw 20 into the hole 2c. You can do it.

Further, in the carriage 30, holes 30c and 30d are formed at the corners of the bottom portion 302 on the side where the vertical portion 301 is not provided, and screw holes 30e and 30f are formed in the substantially central portion of the bottom portion 302 with a predetermined distance therebetween, and the vertical portion 301
Holes 30g and 30h are provided at positions where the shaft portion 30a is not provided. The holes 30c and 30d are for inserting the shafts of the outer groove bearings 31a and 31b, and these outer groove bearings 31a and 31b are rotatable about the Z axis. The guide shaft 3a is engaged with the grooves of the outer groove bearings 31a and 31b.

The screw holes 30e and 30f are coils of a mover of a linear motor (not shown) that moves in parallel with the guide shaft 3a.
It is for fixing with a screw. Further, the holes 30g and 30h are for screwing the carriage 30 and the base 11 with the screws 26a and 26b after adjusting the radial tilt angle, and the side of the base 11 has holes 2f at positions corresponding to the holes 30g and 30h. , 2g are provided.

Similar to the above-described embodiment, one shaft portion of the eccentric pin 8a is fitted to the side surface of the base 11 facing the one side surface, and the other shaft portion of the eccentric pin 8a is a bearing. The holder 32 is adapted to be fitted. The bearing holder 32 includes a bottom portion 321 having a substantially rectangular parallelepiped shape that is long in the X direction, and an arch portion 322 attached to one end of the bottom portion 321 so as to straddle the bottom portion 321. A hole 32a for fitting the other shaft portion of the eccentric pin 8a and a screw hole 32b reaching the hole 32a in the X direction are formed in one leg of the arch portion 322.
The other leg is provided with screw holes 32c and 32d for screwing a coil (not shown) of a mover of a linear motor that moves parallel to the guide shaft 3b. The width of one leg of the arch portion 322 is narrower than that of the other leg, and the hole 32a and the screw holes 32c and 32d are located at different positions in the X direction. A negative groove (not shown) is machined on the head of the other shaft of the eccentric pin 8a, so that the eccentric pin 8a can be rotated by a flat-blade screwdriver.
The position corresponding to the hole 32a of the other leg is omitted. By rotating the eccentric pin 8a, the base 11 can be finely adjusted in the tangential inclination direction (θx direction), and the set screw 21 can be screwed and fixed in the screw hole reaching the hole 2b.

Holes 32e and 32f penetrating in the Z direction are formed in the bottom portion 321 with a predetermined distance therebetween, and the end not having the arch portion 322 has the Y direction for inserting the screw 28. It has a wall portion having a hole 32g penetrating therethrough. The base 11 is provided with a screw hole (not shown) at a position corresponding to the hole 32g.

The holes 32e and 32f are provided with outer groove bearings 33a and 3f.
It is for inserting the shaft of 3b, and these outer groove bearings 33a, 33b are rotatable about the Z axis. The guide shaft 3a is engaged with the grooves of the bearings 33a, 33b with outer grooves. In this way, the guide shaft 3a and the outer grooved bearing 33a,
It is possible to transfer the optical head part 2 in the radial direction of the optical disc 18 by engaging with 33b and engaging with the guide shaft 3a and the grooves of the outer groove bearings 31a and 31b as described above. .

Next, a method of adjusting the tilt angle of the optical head portion 2 will be described. First, by rotating the tilt angle adjusting screw 17, the optical head unit 2 is rotated about the shaft portion 30a of the carriage 30 to perform fine adjustment in the radial tilt direction (θy direction). After that, by tightening the screws 26a and 26b and the set screw 20, the optical head unit 2 is fixed at a required radial inclination angle. Next, by rotating the eccentric pin 8a with a flat-blade screwdriver, the relative height between the optical head unit 2 and the bearing holder 32 is adjusted, and the tangential tilt direction is adjusted. Then, by tightening the set screw 21, rotation of one shaft portion of the eccentric pin 8a is suppressed, and by tightening the set screw 27, rotation of the bearing holder 32 with respect to the other shaft portion of the eccentric pin 8a is suppressed. By tightening the screw 28 for reinforcement, the base 11 can be tilted at the required tangential tilt angle.
And the bearing holder 32 are fixed. Also in this embodiment, it is possible to use it vertically and prevent it from coming off the guide shaft.

As described above, also in this embodiment, the optical head unit 2 can be fixed by adjusting the tilt angle independently in the radial tilt direction and the tangential tilt direction. Further, by using the bearings 31a, 31b, 33a, 33b with outer grooves, it is possible to stably transfer the optical head portion 2 in the radial direction of the optical disk 18 along the two guide shafts 3a, 3b. Further linear ball bearings 4a, 4b
Since the bearings 31a and 31b with outer grooves are used instead, the weight can be further reduced.

In this embodiment, two guide shafts 3a and 3b are provided.
Although it is configured to be supported by individual bearings with outer grooves,
The bearings may be supported by one bearing each having an outer groove. In addition, the guide shafts 3a and 3b are located at the same height, and the bearings with outer grooves are also provided at the corresponding positions, but by changing the heights of the guide shafts 3a and 3b, The bearings may also be provided at the corresponding positions.

FIG. 8 is a front view showing a fourth embodiment of the device of the present invention, showing the YZ plane. In this embodiment, the guide shafts 3a and 3b are supported by two radial ball bearings whose rotary shafts are arranged at a predetermined angle. The carriage 40, which is attached to the base 11 with the same structure as the above-described carriage 30, includes a vertical portion 401, a bottom portion 402, and a bearing attachment portion 403. This bearing mount 40
3 is a right-angled triangle in a front view (a plane viewed from the X direction), and a hypotenuse thereof is perpendicular to the bottom portion 402. Radial ball bearings 41a, 41b are mounted on both sides (both sides) of the right-angled portion so as to form a relatively right angle, and the guide shaft 3a is provided between the radial ball bearings 41a, 41b.
Support.

On the other hand, the guide shaft 3b is also supported by two radial ball bearings 43a and 43b which are also mounted so as to form a relatively right angle. The bearing holder 42 holding the radial ball bearings 43a, 43b has a hole for fitting the other shaft portion of the eccentric pin 8a, and is a right-angled triangle in a front view like the bearing mounting portion 403.

FIG. 9 is a front view showing a fifth embodiment of the device of the present invention, showing the YZ plane. In this embodiment, the guide shaft 3a is supported by the slide bearing, and the guide shaft 3b is supported by the radial ball bearing. Carriage 50 mounted on base 11 in a similar configuration to carriage 30
Is the vertical portion 501, the bottom portion 502, and the bearing mounting portion 503.
Consists of. Inside the bearing mounting portion 503, a sliding bearing 51 is provided in the X direction, and a guide shaft 3a is fitted inside thereof. A hole for inserting the eccentric pin 8a is provided on the side surface of the base 11 facing the side surface to which the carriage 50 is attached, and a radial ball bearing 52 is provided on the other end side of the eccentric pin 8a as in the first embodiment. It is attached. The radial ball bearing 52 is mounted on the guide shaft 3b.

Also in the above-described fourth and fifth embodiments, the optical head portion 2 can be adjusted and fixed to an appropriate tilt angle, and the optical head portion 2 can be moved in the radial direction of the optical disc 18. In addition, it can be made thinner and lighter. Furthermore, since a radial ball bearing or a sliding bearing is used instead of the linear ball bearing, further weight reduction is realized. All the above examples are for recording only,
The present invention can be applied to all types of optical disc devices such as read-only type and recording / playback type.

[0044]

As described above, the optical head transfer mechanism according to the present invention can be made thinner by disposing the carriage on the side of the optical head section. Further, by improving the method of adjusting the radial tilt angle direction of the optical head unit, it is possible to reduce the space required for fine adjustment as compared with the conventional case. Further, by sandwiching one of the guide shafts by a first rolling member having a fixed rotating shaft and a second rolling member having a rotating shaft rotatable about the rotating shaft, the guide shaft The present invention has an excellent effect such that the influence of the dimensional accuracy and the placement accuracy on the sliding characteristics can be reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of an optical head transfer mechanism according to the present invention.

FIG. 2 is a perspective view showing a first embodiment of an optical head transfer mechanism according to the present invention.

FIG. 3 is a front view showing a first embodiment of an optical head transfer mechanism according to the present invention.

FIG. 4 is a side view showing an optical head portion of an optical head transfer mechanism according to the present invention.

FIG. 5 is an exploded perspective view showing a second embodiment of the optical head transfer mechanism according to the present invention.

FIG. 6 is a side view showing a second embodiment of the optical head transfer mechanism according to the present invention.

FIG. 7 is an exploded perspective view showing a third embodiment of the optical head transfer mechanism according to the present invention.

FIG. 8 is a front view showing a fourth embodiment of the optical head transfer mechanism according to the present invention.

FIG. 9 is a front view showing a fifth embodiment of the optical head transfer mechanism according to the present invention.

FIG. 10 is an exploded perspective view showing a conventional optical head transfer mechanism.

[Explanation of symbols]

 2 Optical heads 3a, 3b Guide shafts 4a, 4b Linear ball bearings 7a Radial ball bearings 8a Eccentric pins 12 Objective lens 18 Optical disc 19 Carriage 19d Side part

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 31, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0039

[Correction method] Change

[Correction content]

In this embodiment, two guide shafts 3a and 3b are provided.
Although it is configured to be supported by individual bearings with outer grooves,
Either one may be supported by one bearing having an outer groove. In addition, the guide shafts 3a and 3b are located at the same height, and the bearings with outer grooves are also provided at the corresponding positions, but by changing the heights of the guide shafts 3a and 3b, The bearings may also be provided at the corresponding positions.

Claims (2)

[Claims] 1. A mechanism for moving an optical head unit, which irradiates a light beam condensed by an objective lens onto an optical disc to record or reproduce information, in the radial direction of the optical disc along two parallel guide axes. And a mechanism for adjusting the tilt angle of the optical head unit about the tangential direction of the optical disk by a carriage that is rotatable about an optical axis of the objective lens and an axis perpendicular to the radial direction as a rotation axis, One guide shaft and one side of the optical head portion are positioned via a first rolling element fitted to an eccentric pin integrally provided with shaft portions having different cores, and the other engaged with the carriage. And a mechanism for adjusting the inclination angle of the optical head section around the guide axis of the optical head section, wherein a carriage having an edge projecting toward the optical head section is provided on one side surface of the optical head section. In order to adjust the tilt angle about the tangential direction as an axis by screwing the ridge portion of the carriage and the bottom portion of the optical head portion, a hole is formed on the other side surface of the optical head portion. An optical head transfer mechanism, wherein the eccentric pin is provided in the hole. 2. A bearing holder, which is rotatably fitted to the eccentric pin and in which a pin fitted with a second rolling element is provided upright, the second rolling element and the first rolling element being provided. The optical head transfer mechanism according to claim 1, wherein the one guide shaft is held by a moving body.