JPH05298726A - Guide mechanism of optical-disk pickup - Google Patents

Abstract

PURPOSE:To shorten the access time of an optical disk pickup. CONSTITUTION:The V-groove part of a bar roller 11 provided with the V-groove 11a in the periphery and supported by a pair of rolling bearings 12 is brought into contact with a guide shaft 4. Thus, the space between left and right guide shafts 4 becomes smaller and the lateral width of a linear motor coil 16 provided in the form of surrounding the outside of the guide shafts also becomes smaller so that an optical disk pickup is lightened and an access time is shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guide mechanism for an optical disk pickup device.

[0002]

2. Description of the Related Art An optical disk recording device (which means a device having an optical pickup device generically and includes a magneto-optical disk recording / reproducing device which reproduces information by utilizing the difference in polarization angle) stores a large amount of information. Since it has excellent advantages such as being able to record and accessing the place where the information is recorded to retrieve only that information,
In recent years, its development and utilization have been greatly advanced.

And, in order to speed up the access time,
It is desired to reduce the weight and size of the optical disc pickup device.

In particular, in order to speed up the access time, in recent years, the optical disc pickup device is divided into a fixed part having LDs and PDs and a movable part having a raising mirror, and only the movable part is moved. Is often adopted.

By the way, in these cases, conventionally, a guide mechanism for movably supporting the optical disk pickup device in the radial direction of the optical disk is, for example, as shown in FIG.
A metal bearing 32 is provided at one end of the optical disc pickup device 31, and a rolling bearing 33 and a rolling bearing 3 are provided at the other end.
3 of the pair of guide shafts, one guide shaft 35a is fitted to the metal bearing 32, and the other guide shaft 35b is connected to the rolling bearing 33 and the leaf spring 34. There was a configuration fitted between. However, in this configuration, between the metal bearing 32 and the one guide shaft 35a, and between the leaf spring 34 and the other guide shaft 35.
Since there is a sliding contact with b, the frictional force at the time of movement of the optical disk pickup device 31 is large and the access time cannot be shortened.

Therefore, a structure in which the optical disc pickup device is supported on the guide shaft by rolling contact has been considered. For example, as shown in FIG. 4, a set of rolling bearings 42 mounted on one side of the optical disc pickup device 41 at an angle of 45 ° upward and downward from the horizontal line.
a is arranged at two positions, and is attached to the other side of the optical disc pickup device 41 at an angle of 45 ° above and below the horizontal line.
Is installed at one position, and one set of rolling bearings 42b on this side is attached to the optical disc pickup device 41 with a leaf spring 43 interposed, that is, preloaded.
There has been a structure in which the outer ring of a pair of rolling bearings is brought into contact with the guide shafts 44a and 44b on each side.

[0007]

However, in this structure, the rolling bearings are provided on the both sides of the optical disk pickup device in the vertical direction by 45 degrees, respectively.
Since the outer ring portions of a pair of rolling bearings that are arranged at an angle and are opposed to each other and project outwardly are in contact with the guide shafts, the distance between the guide shafts is increased, and thus the outer sides of the pair of guide shafts are surrounded. There is a problem in that the width of the linear motor coil provided in (1) becomes long, which makes the linear motor coil heavy, and thus makes the optical disk pickup device heavy.

Therefore, an object of the present invention is to provide a guide mechanism for an optical disc pickup device, which can reduce the weight of the optical disc pickup device and shorten the access time when the optical disc pickup device is supported on a guide shaft by rolling contact. To do.

[0009]

In order to achieve the above object, a guide mechanism of an optical disk pickup device of the present invention is supported by a pair of opposed rolling bearings, and a V-shaped groove is provided around the rod-shaped roller. The rod-shaped roller is attached to the optical disc pickup device by supporting the outer ring of the rolling bearing to the optical disc pickup device, and the rod-shaped roller is attached to at least three places in the optical disc pickup device. At least two of the rod-shaped rollers are supported by the same guide shaft from the inside of the pair of opposed guide shafts by abutting the V groove on the guide shaft.

On one side of the pair of guide shafts, the outer rings of the rolling bearings facing each other of the rod-shaped rollers are supported by an arm rotatably supported by the optical disc pickup device main body, and the optical disc pickup device main body and the arm are provided. It is preferable that a compression coil spring is interposed between the two to urge the rod-shaped roller in one direction.

[0011]

The function is supported by a pair of rolling bearings facing each other, and V
Since the V-shaped groove of the rod-shaped roller, which is provided around the groove, is brought into contact with the guide shaft, the distance between the pair of guide shafts can be shortened. Therefore, the linear shape provided so as to surround the outside of the pair of guide shafts. The width of the motor coil can be shortened,
This reduces the weight of the linear motor coil and thus the weight of the optical disc pickup device.

On one side of the pair of guide shafts, the outer rings of the opposed rolling bearings that support the rod-shaped rollers are supported by the arm rotatably supported by the optical disk pickup device main body and the optical disk pickup device main body. By interposing the compression coil spring between the arm and the vertical downward weight of the optical disk pickup device, the weight is supported by the arm and supported by the guide shaft, and therefore the spring constant of the compression coil spring is set to a small value. can do. Therefore, even if the length of the compression coil spring changes slightly in the compressed state, the restoring biasing force does not change significantly. Therefore, even if the length of the compression coil spring in the compressed state during preload varies among individual optical disc pickup devices, it is possible to obtain a predetermined preload value that is almost designed for each individual optical disc pickup device. ..

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS.

In FIG. 2, the optical disc pickup device 1 is of a separated optical type, and has a fixed optical part 2 fixed to the main body of the optical disc recording device and a guide shaft 4 provided in the radial direction of the optical disc 3 (omitted in FIG. 2, It has a movable optical part 6 that moves along the direction (see FIG. 1). The movable optical unit 6 is a uniaxial actuator that only performs focus adjustment. Permanent magnets 7 (omitted in FIG. 2, see FIG. 1) are arranged parallel to the guide shaft 4 on both sides of the movable optical unit 6. The tracking adjustment is performed by rotating a plane mirror 8a of the galvanometer scanner 8 arranged at a position orthogonal to the optical axis of the fixed optical unit 2 and the optical axis of the movable optical unit 6. The optical disc 3 is a compact disc for reproduction only, and information is recorded by arranging the protrusions 3a.

Next, the movable optical section 6 will be described.

The rod-shaped roller mounting member 9 of the movable optical section 6 is
It has an H-shaped cross section with the recess facing toward the side, and a through hole 9a for passing a laser beam is provided in the central part, and the through hole 9a is connected to the inner part of the rod-shaped roller mounting member 6a. Then, a vertical hole (not shown) orthogonal to the upper side is formed. A rising mirror (45 ° mirror, not shown) is provided at the connection position between the through hole 9a and the vertical hole.
Therefore, the laser beam is refracted by the rising mirror,
Proceed through the through hole 9a and the vertical hole.

Next, two rod-shaped rollers 11 are attached to the recess 9b on the right side of the rod-shaped roller attachment member 9 at the front and rear positions. As shown in FIG. 1, the rod-shaped roller 11 has a shape in which a V groove 11a is provided around the center thereof,
Both ends are fixed to and supported by the inner ring of the rolling bearing 12 composed of a pair of radial ball bearings. Then, the rod-shaped roller 11 is arranged in the recess 9b with the axis line in the vertical direction, and the outer ring of the rolling bearing 12 is fixed to the upper surface 9c and the lower surface 9d of the rod-shaped roller mounting member 9.

Next, in the recess 9f on the left side of the rod-shaped roller mounting member 9, one bar-shaped roller 11 is attached to the recess 9 on the right side.
It is arranged at a position approximately in the middle of the two bar-shaped rollers 11b. The configuration of the rod-shaped roller 11 in the depression 9f on the left side is the same as that on the right side. And one rod-shaped roller 11
The outer ring of the rolling bearing 12 is rotatably supported on the rod-shaped roller mounting member 9 at both ends by a shaft support 13a provided at a position slightly centered from the position of the recess 9f on the left side. The arm 13 is fixed to the free end of the arm 13 and is attached to the rod-shaped roller attachment member 9. A compression coil spring 14 is interposed between each arm 13 and the rod-shaped roller mounting member 9. Therefore, one rod-shaped roller 11 is biased toward the outside of the recess 9f on the left side. When the movable optical unit 6 is supported by the pair of guide shafts 4, the vertically downward weight of the movable optical unit 6 is supported by the arms and supported by the guide shafts 4. Therefore, the spring constant of the compression coil spring 14 can be set to a predetermined small value as compared with the case where the conventional leaf spring of FIG. 4 is used. Therefore, at the time of preloading, the compression coil spring 14 is compressed by the arm 1 while being compressed to a predetermined length.
3, that is, when the biasing force is applied to the rod-shaped roller 11, even when the compressed length of the compression coil spring 14 varies due to an attachment error or the like in the assembly of the individual optical disk recording devices, the spring as described above is used. Since the constant is a predetermined small value, the biasing force does not change significantly. Therefore, in each optical disk recording device, it is possible to provide a predetermined preload urging force of approximately the designed value.

All the bar-shaped rollers 11 having V-grooves are arranged on the bar-shaped roller mounting member 9 with their axis lines in the vertical direction, and are supported by the opposing rolling bearings so that the outer ring is mounted on the bar-shaped roller mounting member 9. Since it is attached, the guide mechanism of the optical disk pickup device is extremely simple, and therefore the guide mechanism can be manufactured with extremely high accuracy.
In addition, it can be manufactured easily and inexpensively.

Next, a pair of guide shafts 4 are arranged outside the rod-shaped rollers 11 on both sides of the rod-shaped roller mounting member 9 so as to be fixed to the optical disk recording apparatus. Each of the guide shafts 4 is composed of an abutting member 4a that abuts the V groove 11a of the rod-shaped roller 11 and a rigid member 4b that is positioned outside the abutting member 4a and that supports the abutting member 4a. Since the contact member 4a of the guide shaft 4 contacts the V groove 11a of the rod-shaped roller 11, the position of the contact member 4a can be near the central axis of the radial ball bearing 12, and thus the position of the contact member 4a. Can be located inward of the outer ring of the ball bearing 12, thereby reducing the distance between the pair of abutting members 4a, and thus the outer side of the pair of rigid members 4b. The distance between the ends can be reduced.

Next, the rod-shaped roller mounting member 9 is provided with a linear motor coil 16 having a rectangular cross section so as to surround the rigid member 4b of the guide shaft 4. Since the distance between the outer ends of the pair of rigid members 4b is small, the lateral width of the linear motor coil 16 can be reduced. Therefore, the weight of the linear motor coil 16 can be reduced, and since the main part of the weight of the movable optical unit 6 is occupied by the linear motor coil 16, the weight of the movable optical unit 6 can be significantly reduced. When a current flows through the linear motor coil 16, the movable optical unit 6 causes the movable optical unit 6 to move according to the Fleming's law that acts between the linear motor coil 16 and the permanent magnet 7 arranged outside the linear motor coil 16.
Move in the radial direction.

Next, the focus actuator 17 is arranged in front of the linear motor coil 16. The other end of the leaf spring 18 fixed to the upper and lower surfaces of the end of the rod-shaped roller mounting member 9 is fixed to the upper and lower surfaces of the focus actuator 17. Therefore, the focus coil 19 provided on the side of the focus actuator 17
When a current flows through the focus actuator 17, the focus actuator 17 is supported by the leaf spring 18 and moves up and down according to Fleming's law acting between the permanent magnet 7 and the permanent magnet 7 arranged outside the focus actuator 17.
The objective lens 21 provided facing the vertical hole of the rod-shaped roller mounting member 9 moves up and down.

Since the space between the pair of guide shafts 4 and the space between the pair of permanent magnets 7 can be narrowed, the optical disk recording apparatus using the guide mechanism of the present invention can be miniaturized.

When the optical disk recording apparatus is driven as described above, a current flows through the linear motor coil 16 in the movable optical section 6 so that the V groove 11a of the rod-shaped roller 11 abuts the guide shaft 4. The rod-shaped roller 11 rotates with the inside of the ball bearing 12 to access a specified position on the optical disc 3. Since the V groove 11a is fitted to the guide shaft 4, the vertically downward weight of the movable optical unit 6 is supported. Then, at the access position, a current flows through the focus coil 19 and the focus actuator 17 moves up and down to perform focusing, and the galvanometer scanner 8 moves to perform tracking, while the laser emitted from the fixed optical unit 2 is moved. The beam hits the projection 3a of the optical disc, and the reflected light returns to the fixed optical unit 2 to reproduce the recorded information.

The weight of the movable optical section 6 is extremely reduced, the movable optical section 6 is in rolling contact with the guide shaft 4, and the preload biasing force is applied by the compression coil spring 14. , The preload urging force can be set to a substantially predetermined value and does not become a large value. With these, access to the specified position on the optical disk 3 of the movable optical unit 6 is performed very quickly, and information of Fast playback takes place. Further, since the guide mechanism has high accuracy, it is possible to access an extremely accurate position.

Although the above embodiment has been described with respect to the case of the uniaxial actuator, the present invention is naturally applicable to the case of a biaxial actuator which performs focusing and tracking by the movable optical portion. Further, although the above embodiment has been described with respect to the case of the separation optical type, the present invention can be applied to the case of the integrated optical type.

[0027]

Since the present invention is configured as described above, it is possible to reduce the weight of the optical disc pickup device, shorten the access time, and downsize the optical disc recording device.

Further, since the guide mechanism is simple, a highly accurate guide is possible, and the guide mechanism is easy and inexpensive to manufacture.

[Brief description of drawings]

FIG. 1A is a plan view of an optical disk pickup device of the present invention, and FIG. 1B is a sectional view taken along the line AA of FIG.

2 is an overall perspective view of the optical disk pickup device of FIG. 1. FIG.

FIG. 3 is a schematic diagram of a conventional optical disc pickup device.

FIG. 4 is a schematic view of a conventional optical disc pickup device.

[Explanation of symbols]

 1 Optical Disk Pickup Device 4 Guide Shaft 11 Rod Roller 11a V Groove 12 Rolling Bearing 13 Arm 14 Compression Coil Spring

Claims (2)

[Claims] 1. A pair of rolling bearings which are opposed to each other,
A rod-shaped roller having a V-shaped groove is supported on the optical disc pickup device by supporting an outer ring of the rolling bearing on the optical disc pickup device, and at least the rod-shaped roller is The rod-shaped rollers are attached to the optical disk pickup device at three locations. The rod-shaped rollers are arranged inside the pair of opposed guide shafts, and at least two of the rod-shaped rollers are arranged on the same guide shaft, and the V-shaped groove is formed on the guide shaft. A guide mechanism for an optical disk pickup device, which is supported by abutting. 2. The outer ring of the rolling bearings of the rod-shaped rollers facing each other on one side of the pair of guide shafts is supported by an arm rotatably supported by the optical disk pickup device main body. A guide mechanism for an optical disc pickup device, wherein a compression coil spring is interposed between the main body of the optical disc pickup device and the arm to urge the rod-shaped roller in one direction.