JP3325438B2 - Objective lens driving device, information recording device and information reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an objective lens driving device, an information recording device and an information reproducing device.

[0002]

2. Description of the Related Art In recent years, with the development of optical information recording media such as optical disks and magneto-optical disks, the development of an objective lens driving device used in a reproducing apparatus for these optical information recording media has been actively performed. The objective lens driving device has already been generally and widely used as a CD-ROM represented by a compact disk (CD) or a laser disk (LD).

Recently, an objective lens driving device has been developed not only as a reproducing device but also as an optical recording device. In particular, a recording method using an MO (Magnet-optical) method or a PC (Phase-Change) method has been developed. Are known.

[0004]

Generally, the recording structure of an optical disk or a magneto-optical disk is defined by standards. However, it is expected that the recording density will improve over time. For example, the size of a pit, which is a unit for recording information, is likely to reach submicron from about 1 micron at present.

[0005] In order to realize this, the wavelength of the laser beam to be used is shortened, or the NA (Number) of the objective lens is reduced.
A device has been devised to reduce the spot diameter of the light beam by increasing the aperture of the aperture.

[0006] Also, discs having different substrate thicknesses have been born as a new standard, and there is a danger that information on a disc of the conventional standard cannot be recorded or reproduced with a new device.

[0007] In order to be able to handle discs of any standard, a plurality of devices must be prepared, so that costs are high and efficient recording / reproducing processing cannot be performed. There is.

Therefore, it is desired that a single device can record / reproduce not only the conventional standard optical disk and magneto-optical disk but also the new standard optical disk and magneto-optical disk.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an objective lens driving apparatus capable of recording / reproducing a plurality of optical disks and magneto-optical disks having different standards and characteristics with one apparatus. It is an object to provide an information recording device and an information reproducing device.

Further, the present invention provides an objective lens driving device, an information recording device, and an information reproducing device which realize a good recording / reproducing operation without causing coma and the like when recording / reproducing an optical disk or a magneto-optical disk. It is intended to provide a device.

Further, the present invention provides an objective lens driving device which realizes a good recording / reproducing operation without danger of cutting a lead wire when recording / reproducing an optical disk or a magneto-optical disk with one device. It is an object to provide an information recording device and an information reproducing device.

[0012]

In order to achieve the above object, an objective lens driving device according to the present invention comprises an optical information recording medium.
A carriage movable on the body, and standing on the carriage;
A rotating shaft provided, and a first rotatable around the rotating shaft.
A movable body, and an optical system provided on the first movable body.
Multiple objective lenses with different characteristics and around the rotation axis
Rotatable and before the first movable body is attracted by magnetic force
A second movable body rotatable together with the first movable body;
Through a desired one of a plurality of objective lenses;
In order to guide the light beam to the optical information recording medium, the first
And by rotating and positioning the second movable body
Selectively rotate and position one of the objective lenses
And a drive unit for determining.

In the objective lens driving device, it is preferable that a magnetic body is attached to the first movable body, and a magnet that generates an attractive force to the magnetic body is attached to the second movable body. .

It is preferable that a coil capable of supplying a current for controlling the driving of the first movable body is attached to the first movable body. In this case, it is preferable that a lead wire for supplying a current to the coil is connected to the outside by relaying the second movable body from the first movable body.

Preferably, the first movable body is formed such that its center of gravity is located on the rotation axis. Further, it is preferable that the carriage is configured to be movable to the outside of the optical information recording medium.
In this case, it is preferable that the drive unit includes a drive gear that meshes with the second movable body when the carriage moves to the outside of the optical information recording medium, and a motor that rotates the drive gear. . Alternatively, the driving unit includes:
It is preferable that a lever is provided to abut the second movable body so that the second movable body is rotated while the carriage moves to the outside of the optical information recording medium.

In addition, the second carriage is provided on the carriage.
It is desirable that an intermediate gear meshing with the movable body is mounted. In this case, it is preferable that the drive section includes a drive gear that meshes with the intermediate gear when the carriage moves to the outside of the optical information recording medium, and a motor that rotates the drive gear. Alternatively, it is preferable that the driving unit includes a lever that comes into contact with the intermediate gear so that the intermediate gear is rotated while the carriage moves outside the optical information recording medium.

According to another aspect of the present invention, there is provided an information recording apparatus, comprising: a carriage movable on an optical information recording medium; a rotating shaft erected on the carriage; A first movable body rotatable about the first movable body, a plurality of optical elements of different standards provided on the first movable body, and a first movable body rotatable about the rotation axis;
The second movable body rotatable together with the first movable body by attracting the movable body with magnetic force, and data recording on the optical information recording medium is performed by a desired optical element among the plurality of optical elements. A driving unit that selectively rotates and positions one of the plurality of optical elements by rotating and positioning the first and second movable bodies. I do.

According to another aspect of the present invention, there is provided an information reproducing apparatus, comprising: a carriage movable on an optical information recording medium; a rotating shaft erected on the carriage; A first movable body rotatable therearound, and a plurality of optics provided on the first movable body and having different standards.
An element and rotatable about the rotation axis;
The second movable body rotatable with the first movable body by attracting the movable body with magnetic force, and the desired optical element among the plurality of optical elements reproduces data from the optical information recording medium. Rotating and positioning the first and second movable bodies to thereby adjust the position of the plurality of optical elements.
And a drive unit for selectively rotating and positioning one of them.

In the information recording device and the information reproducing device, a magnetic body is attached to the first movable body.
It is preferable that a magnet that generates an attractive force to the magnetic body is attached to the second movable body.

Further, it is preferable that a coil capable of supplying a current for driving control of the first movable body is attached to the first movable body. In this case, it is preferable that a lead wire for supplying a current to the coil is connected to the outside by relaying the second movable body from the first movable body.

Preferably, the first movable body is formed such that its center of gravity is located on the rotation axis. Preferably, each of the plurality of objective lenses has a different numerical aperture.

It is desirable that the carriage is configured to be movable to the outside of the optical information recording medium. In this case, it is preferable that the drive unit includes a drive gear that meshes with the second movable body when the carriage moves to the outside of the optical information recording medium, and a motor that rotates the drive gear. . Alternatively, it is preferable that the driving unit includes a lever that comes into contact with the second movable body so that the second movable body is rotated while the carriage moves to the outside of the optical information recording medium. .

In addition, the carriage has the second
It is desirable that an intermediate gear meshing with the movable body is mounted. In this case, it is preferable that the drive section includes a drive gear that meshes with the intermediate gear when the carriage moves to the outside of the optical information recording medium, and a motor that rotates the drive gear. Alternatively, it is preferable that the driving unit includes a lever that comes into contact with the intermediate gear so that the intermediate gear is rotated while the carriage moves outside the optical information recording medium.

According to the above configuration, a plurality of objective lenses (or heads) are mounted on one apparatus, and these objective lenses and the like are mounted on an information storage medium (optical disk or magneto-optical disk) on which the objective lenses are mounted. It is controlled so that it can be appropriately switched according to the type. Therefore, it is possible to record / reproduce not only the conventional standard optical disk and magneto-optical disk but also the new standard optical disk and magneto-optical disk with one apparatus. That is, it is possible to realize recording / reproducing of a plurality of optical disks and magneto-optical disks having different standards and characteristics by one apparatus.

In particular, according to the present invention, a magnet (a part of a magnetic circuit) for rotationally driving the first movable body on which the objective lens is mounted is attached to the second movable body. It is characterized in that it is configured to be able to rotate around a central axis. Therefore, since the inclination of the movable body with respect to the rotation axis does not change, if the optical axes of a plurality of objective lenses are adjusted so that they coincide when assembling the apparatus, any one of the objective lenses can be used when the apparatus is driven. It is also possible to realize a good recording / reproducing operation without generating coma or the like.

Further, even if the second movable body rotates, the relative position between the first movable body and the second movable body hardly changes, so that a lead wire or the like is moved from the first movable body to the second movable body. By connecting to the outside by relaying, it is possible to realize a good recording / reproducing operation without danger such as disconnection of a lead wire.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) First, a first embodiment of an information recording / reproducing apparatus according to the present invention will be described with reference to FIGS. Here, FIG. 1 is a plan view of an optical disk device which is a kind of information recording / reproducing device, FIG. 2 is a plan view of an objective lens driving device incorporated in the optical disk device, FIG. 3 is a sectional view of the objective lens driving device, and FIG. FIG. 2 illustrates an optical processing system and a signal processing system.

As shown in FIG. 1, a disk 1 (optical disk, magneto-optical disk, etc.) for recording and reproducing information
Is held by a chucking means such as a magnet chuck with respect to a spindle motor 3 fixed to the base 2, and is stably rotated by the spindle motor 3 during recording and reproduction.

A carriage 4 is arranged at a position near the lower portion of the disk 1. The carriage 4 has a first movable body 5 and a second movable body 6 mounted thereon. As described later, the first movable body 5 is supported so as to be movable in the radial direction and the thickness direction of the disk 1, and the second movable body 6 is supported so as to be movable only in the radial direction of the disk 1. . That is, both the first and second movable bodies 5 and 6 are rotatable about their respective axes.

As shown in FIG. 3, the first movable body 5 comprises a flat blade 5a facing the surface of the disk 1 and a cylindrical coil bobbin 5b fixed below the blade 5a. The blade 5a and the coil bobbin 5
A slide bearing 5c is provided at the center of b.

A rotating shaft 7 having one end fixed to a fixed portion (non-rotating portion) 4a of the carriage 4 is inserted and fitted into the sliding bearing 5c through a minute gap (10 microns or less).
It constitutes a sliding bearing mechanism (shaft sliding mechanism). And
The first movable body 5 is capable of rotational movement about the rotation axis 7 and translational movement in the axial direction.

A plurality of, here two, objective lenses 8a, 8b are fixed on the blade 5a with a space therebetween. These objective lenses 8a and 8b have different optical characteristics (for example, the numerical aperture (NA) of the objective lens 8a is 0.45
The numerical aperture of the objective lens 8b is selected to be 0.6). The mounting positions of these two objective lenses 8a and 8b are adjusted so that the center of gravity of the total mass of the first movable body 5 is substantially coincident with the rotation axis 7. That is, the first movable body 5 has a structure in which the weight is balanced with respect to the rotating shaft 7 by the two objective lenses 8a and 8b.

As shown in FIG. 2, on the side face of the coil bobbin 5b, two rectangular focus coils 9a and 9b wound flatly, and similarly, a rectangular wound coil flatly wound. Tracking coils 100a, 100b
Is affixed. Two focus coils 9a, 9b
Are respectively attached at positions symmetrical with respect to the rotation axis 7, and two tracking coils 100a, 10a
Similarly, 0b is stuck at a position symmetrical with respect to the rotation axis 7, respectively.

The focus coils 9a, 9
b and on the second movable body 6 around the tracking coils 100a and 100b, the permanent magnets 10a, 10b, 1
Magnetic circuits 12a and 12b are provided. As shown in FIG. 2, the focus coils 9a, 9b and the tracking coils 100a, 100b are composed of permanent magnets 10a, 10b.
b, 101a, 101b and the yokes 11c, 11d, and are opposed to each other via a magnetic gap of a predetermined length. And the permanent magnets 10a, 1
0b corresponds to the focus coils 9a and 9b, and the permanent magnets 101a and 101b correspond to the tracking coils 100a and 1b.
00b is provided with a magnetic field.

The yokes 11a to 11d constituting the magnetic circuits 12a and 12b are fixed on the second movable body 6 by means such as welding or caulking. Here, the magnetization directions of the permanent magnets 10a and 10b coincide with the axial direction of the rotating shaft 7, and the magnetization directions of the permanent magnets 101a and 101b are orthogonal to the magnetization directions of the permanent magnets 10a and 10b. Matches. Further, the two magnetic circuits 12a, 12
b has the same structure.

The focus coils 9a and 9b
And the magnetic flux from the permanent magnets 10a and 10b generates Lorentz force, and the first movable body 5 is finely translated in the thickness direction of the disk 1 (axial direction of the rotating shaft 7). . Also, while the tracking coils 100a and 100b are energized,
The Lorentz force is generated by receiving the magnetic flux from 1a and 101b, and the first movable body 5 is driven to rotate minutely in the radial direction of the disk 1 (around the rotation axis 7).

Further, two magnetic members 110a and 110b made of iron pieces or the like are provided at the center (hollow portion in a wound state) of the tracking coils 100a and 100b attached to the side surface of the coil bobbin 5b. These magnetic materials 1
10 a and 110 b are attached at positions symmetrical with respect to the rotation axis 7. When one of the objective lenses 8a and 8b is in the optical path 24 (described later), these magnetic members 110a and 110b are connected to the permanent magnets 101a and 101b of the magnetic circuits 12a and 12b and the yokes 11c and 11d. The relationship is sandwiched.

As shown in FIG. 3, a sliding bearing 6a is provided at the center of the second movable body 6 so as to fit with the rotating shaft 7. The sliding bearing 6a is inserted and fitted to the rotating shaft 7 via a minute gap (10 microns or less), and constitutes a sliding bearing mechanism that allows only rotation. Therefore, the second movable body 6 can rotate independently of the first movable body 5. As shown in FIG. 2, stoppers 32a and 32b are provided on the fixed portion 4a of the carriage 4, and the stoppers 32a and 32b hold the second movable body 6 so as not to move in the axial direction of the rotating shaft 7. I do.

The sliding bearing 6a is fixed to the second movable body 6 by means of ultrasonic welding, heat welding, bonding or the like. As shown in FIG. 3, an elastic body (for example, a spring coil or a coil spring) or a viscoelastic body (for example, between the sliding bearing 5c of the first movable body 5 and the sliding bearing 6a of the second movable body 6). A first spacer ring 102 made of silicone rubber or butyl rubber) and a second spacer ring 103 having a smaller coefficient of friction than the first spacer ring 102 are stacked. The first spacer ring 102 is fixed to the slide bearing 6a,
The spacer ring 103 is opposed to the second sliding bearing 5c. It is preferable that the coefficient of friction between the second spacer ring 103 and the second sliding bearing 6a is set to, for example, 0.4 or less, so that both can be prevented from being adsorbed.

As shown in FIG. 2, first terminals 104a and 104b connected to the focus coils 9a and 9b are provided above the blade 5a, and the second terminals 105a and 104b on the magnetic circuit 12a are provided. 105b is connected via lead wires 106a and 106b. Similarly, first terminals 104c and 104d connected to the tracking coils 100a and 100b are provided, and second terminals 105c and 104c on the magnetic circuit 12b are provided.
105d is connected via lead wires 106c and 106d. These lead wires 106a to 106d
Are used to supply power (current) to the focus coils 9a and 9b and the tracking coils 100a and 100b.

A flexible printed circuit board 107 is connected between the second terminals 105a to 105d on the magnetic circuits 12a and 12b and an external power supply (not shown). Flexible printed circuit board 10
As 7, a member longer than half the outer peripheral length of the second movable body 6 is employed, and as shown in FIG. 2, the member 7 is disposed in a state of being curved substantially in a U-shape. .

On the other hand, a rotary shaft 7 is erected and fixed to the fixed portion 4a of the carriage 4, and the first movable member 5 and the second movable member 6 are held and mounted via the rotary shaft 7. FIG.
As shown in FIG. 5, a pair of radial coils 13a and 13b are attached to both ends of the fixed portion 4a of the carriage 4 at the same distance from the center of gravity of the carriage 4. A magnetic field is applied to these radial coils 13a and 13b from radial magnetic circuits 14a and 14b fixed to the base 2.

The radial magnetic circuits 14a, 14b are composed of back yokes 15a, 15b and center yokes 16a, 16a.
b and permanent magnets 17a and 17b, and the radial coils 13a and 13b are connected to the center yokes 16a and 16b.
b and is movably inserted into a magnetic gap defined by the permanent magnets 17a and 17b. The two radial magnetic circuits 14a and 14b have the same structure, and the direction of magnetization of the permanent magnets 17a and 17b matches the thickness direction of the magnetic gap.

Also, two to four sliding bearings 19a and 19b are provided on the left and right sides of the fixed portion 4a of the carriage 4 (FIG. 2).
), And two guide rails 18a and 18b are arranged in parallel with each other so as to be inserted into these slide bearings. Both ends of the guide rails 18a and 18b are fixed to the base 2. The carriage 4 has these guide rails 18a, 1
8b.

When the radial coils 13a, 13b are energized while receiving the magnetic flux from the radial magnetic circuits 14a, 14b, a Lorentz force is generated, and the second movable body 6 translates in the radial direction of the disk 1. Driven.

Note that the magnetic gap width of the radial magnetic circuits 14a and 14b is such that the second movable body 6
a, 18b so that the objective lenses 8a, 8b can be moved in the radial direction from the outermost circumference to the innermost circumference of the disk 1.
It is formed long enough in the same direction.

Here, the radial magnetic circuits 14a and 14b
Has a length that allows the objective lenses 8a and 8b mounted on the carriage 4 to be moved further outside the outermost periphery of the recording area of the disk 1. When the carriage 4 moves outside the outermost periphery of the disk 1, a drive gear (pinion) 108 of a drive motor fixed to the base 2 is provided on a side surface of the second movable body 6. (See FIG. 4). By rotating the drive gear 108 by the drive motor, the second movable body 6 can be rotated by an arbitrary angle.

Next, an optical system and a signal processing system of the present apparatus will be described. As shown in FIG. 4, laser light for irradiating the disk 1 is generated by an optical unit 20 fixed to a lower portion of the movable body 4 and movable integrally with the movable body 4. The laser beam LB emitted from the semiconductor laser 21 in the optical unit 20 is converted into a parallel beam through the collimator lens 22, is bent by 90 ° by the first beam splitter 23a, and is bent in the carriage 4 from the radial direction of the disk 1 It is led to. An optical path (specifically, a space) 41 for introducing the laser light LB is provided at the bottom of the carriage 4, and the laser light LB passes through the optical path 41 and enters the objective lens 8 (8 a or 8 b). . The laser beam LB incident on the objective lens 8 has a predetermined convergence, and is condensed on the information storage surface of the disk 1.

Here, when the system is in the information reproducing state, the laser beam LB guided to the disk 1 is intensity-modulated according to the information recorded on the information storage surface, that is, the presence or absence of minute pits. It is returned to the objective lens 8 again.
The reflected laser beam LB returned to the objective lens 8 is
It passes through the inside and is again guided to the fixed optical unit 20. Then, the light passes through a first beam splitter 23a, is divided into two paths by a second beam splitter 23b, and is divided into two paths by focusing lenses 24a and 24b, respectively.
5a and the second photodetector 25b.

The reflected laser beams LB guided to the photodetectors 25a and 25b are respectively converted into electric signals corresponding to the size of the beam spot, and are respectively provided to a track control circuit 27 and a focus control circuit provided in the control unit 26. The signal is supplied to a circuit 28. The signals generated by the track control circuit 27 and the focus control circuit 28 are
The focus offset signal and the track offset signal of (8a, 8b) are used for focus direction control and track direction control.

A position shift (focus shift) of the objective lens 8 in the focus direction is detected by using the focus offset signal and the track offset signal, and a current value applied to the focus coils 9a and 9b is controlled so as to correct the position shift. Is done. Further, a position shift of the objective lens 8 in the track direction is detected by using the track offset signal, and a current value applied to the tracking coils 100a and 100b is controlled so as to correct the position shift.

The reflected laser beam LB guided to the photodetector 25b is also supplied to the information reproducing circuit 29. The information in the information reproducing circuit 29 is various kinds of information recorded on the disk 1, and is sent to a host system (not shown) (not shown) such as a character or a still image or a moving image from a display. Output as audio. In this case, the carriage 4
Is controlled to move along the track on the information storage surface of the disk 1 in the radial direction of the disk 1 by large drive or minute drive.

In the control section 26, a recording signal generating circuit 30 for generating a recording signal in accordance with information input from an external host system (for example, a personal computer or the like) not shown, and the objective lens 8a, 8b It includes an objective lens switching circuit 31 that generates a signal for controlling the rotation of the first movable body 6 so that one of them is arranged in the optical path 24 of the laser beam LB.

Next, a mechanism for switching the two objective lenses 8a and 8b will be described. The disc 1 that can be used in the apparatus of the present invention is not limited to one kind of disc as in the related art, but may be a plurality of discs having different standards such as disc recording density, warpage tolerance, disc substrate thickness and the like. Different types of discs are available. For example, C
Not only D-ROM disks but also MO disks and PC disks can be used. As the two objective lenses 8a and 8b, those adapted to the processing of an available disc are prepared.

For example, when using a disk that requires a small spot diameter of the laser beam LB, an objective lens having a large numerical aperture (NA) is selected, and it is necessary to increase the spot diameter of the laser beam LB. When a disk is used, an objective lens having a small numerical aperture (NA) is selected.

The user of the apparatus mounts the target disc 1 on the spindle motor 3, and receives information indicating the type of the disc 1 (for example, a CD-ROM disc, a PC disc, etc.) from a host system (for example, a personal computer). Information as a different disc).
This input information is sent to the objective lens switching circuit 31 to control the objective lens 8 to move on the optical path 41 of the laser beam LB.

Next, the operation of the present apparatus will be described. This first
In the embodiment, when switching between the objective lenses 8a and 8b, the magnetic circuits 12a and 12b mounted on the second movable body 6 are used.
The rotation drive control of b is performed.

First, upon receiving a signal from the objective lens switching circuit 31, the carriage 4 is driven to move further outside the outermost periphery of the disk 1. Then, the drive gear 108 of the drive motor fixed to the base 2 and the rack 109 are engaged with each other as shown in FIG.
When a rotational force is applied by the drive motor after detecting the state in which both are engaged, this rotational force is transmitted to the second movable body 6, and as a result, the magnetic circuits 12a and 12b can be rotated.

Here, two magnetic bodies 110a and 110b are attached to the first movable body 5 as described above. Therefore, the first movable body 5 includes these magnetic bodies 110a, 1
10b is the permanent magnet 1 of the magnetic circuits 12a and 12b.
In a state of being sandwiched between the first and second yokes 11a and 101b and the yokes 11c and 11d, the attraction force is maximized, and magnetically stable. That is, as described above, the magnetic circuits 12a and 12a
b, the first movable body 5 is magnetically attracted to the permanent magnets 101a and 101b.
Will rotate with it. For example, the second movable body 6
Is rotated by 180 °, the first movable body 5 can be automatically rotated by 180 °. Thus, the switching of the objective lenses 8a and 8b can be performed.

When the desired objective lens corresponding to the loaded disk 1 already exists on the optical path 41, there is no need to rotate the second movable body 6. As described above, according to the first embodiment, the two objective lenses can be switched and used in accordance with the disc standards and specifications. 2) It is not necessary to prepare a plurality of objective lens driving devices. Therefore, an objective lens driving device capable of handling various information satisfactorily with only one device is provided.

According to the first embodiment, since the rotating shaft 7 is fixed to the fixed portion 4a of the carriage 4,
The inclination of the blade 5a with respect to the rotating shaft 7 does not change. Therefore, if the optical axes of the objective lens 8a and the objective lens 8b are adjusted so as to be substantially coincident with each other at the time of assembling the device, coma aberration or the like may occur even when the objective lens 8a or 8b is used when the device is driven. Therefore, the recording / reproducing operation can be performed favorably.

Further, the first movable body 5 and the magnetic circuit 12a,
The relative position with respect to 12b (the second movable body 6) changes only by a few degrees when the first movable body 5 is driven to rotate minutely. Because of this, since the boundary conditions at both ends of the lead wires 106a to 106d connecting the first movable body 5 and the second movable body 6 hardly change, the objective lens 8
Even in a situation where it is necessary to rotate a and 8b by 180 °, there is a great effect in practical use such that the risk that these lead wires 106a to 106d are cut can be avoided.

(Second Embodiment) Next, a second embodiment of the information recording / reproducing apparatus of the present invention will be described with reference to FIG. In addition, about the same component as 1st Embodiment mentioned above,
The same reference numerals are given and duplicate descriptions are omitted.

The difference between the second embodiment (FIG. 5) and the first embodiment (FIG. 1) lies in a specific method for switching the objective lenses 8a and 8b. In the above-described first embodiment, the drive gear 108 and the drive motor for rotating the drive gear are employed, whereas in the second embodiment, the first protrusion 121, the second protrusion 122, and the first A lever 123 and a second lever 124 are employed.

That is, in the process of moving the carriage 4 further outside the outermost periphery of the disk 1 in order to rotate the magnetic circuits 12a and 12b, the first projections provided on the second movable body 6 121 is brought into contact with a first lever 123 fixed to the base 2. If such a method is adopted, the magnetic circuit 12 is moved in accordance with the amount of movement of the carriage 4.
The rotation angles of a and 12b can be arbitrarily changed.

In order to rotate the magnetic circuits 12a and 12b in the opposite direction, a second projection 122 projecting from the second movable body 6 is connected to a second lever 124 having one end fixed to the base 2. Should be brought into contact with.

The first lever 123 may be provided with a spring function. That is, the first lever 1
By rotating the magnetic circuits 12a, 12b by about 90 ° by bringing the 23 into contact with the first protrusion 121, the remaining 90
The minute may be automatically rotated by a spring force. In such a case, the second lever 124 is retracted in the direction A using a cam or the like (not shown) to a position where collision with the second protrusion 122 is avoided. Conversely, the magnetic circuit 1
When rotating 2a and 12b, the first lever 123 is moved to the first protrusion 12 using a cam (not shown) or the like.
The robot is retracted in the direction A to a position where collision with the vehicle 1 is avoided.

As described above, according to the second embodiment, the same effects as those of the first embodiment can be obtained, and of course, the second movable member 6 (magnetic circuits 12a, 12b
), Which eliminates the need for expensive devices such as motors for rotating the magnetic circuits 12a and 12b, thereby reducing the manufacturing cost.

(Third Embodiment) Next, a third embodiment of the information recording / reproducing apparatus of the present invention will be described with reference to FIGS. Note that the same components as those in the above-described first embodiment are denoted by the same reference numerals, and redundant description will be omitted.

The third embodiment (FIG. 6) differs from the second embodiment (FIG. 5) in a specific method for switching between the objective lenses 8a and 8b. In the above-described second embodiment, the first protrusion 121, the second protrusion 122,
While the third lever 123 and the second lever 124 are employed, the third embodiment employs an intermediate gear 131, a driving gear 132, and a driving motor for rotating the driving gear.

That is, in the third embodiment, the intermediate gear 131 fitted to the second movable body 6 is provided on the carriage 4 main body, and the drive gear 132 and the drive gear 1
A drive motor for rotating 32 is installed on the base. A driving force for rotating the magnetic circuits 12a and 12b is transmitted from the driving gear 132 to the second movable body 6 via the intermediate gear 131. When the carriage 4 moves outside the outermost periphery of the disk 1,
The intermediate gear 131 meshes with a drive gear 132 of a drive motor fixed to the base 2. By rotating the drive gear 132 with the drive motor, the second movable body 6 can be rotated by an arbitrary angle.

FIG. 7 shows the second movable body 6 and the intermediate gear 131.
FIG. 4 is a cross-sectional view illustrating a structure of the objective lens driving device in a state where the and are fitted. As shown in the figure, the second movable body 6 includes:
A groove 133 is provided. A stopper pin 134 is provided upright at one end of the fixed portion (non-rotating portion) of the carriage 4, and the stopper pin 134 is engaged with the groove 133. Here, the stopper pin 13
Reference numeral 4 is provided on a straight line connecting the rotation shaft 7 and the rotation center of the intermediate gear 131.

FIG. 8 is a plan view of the second movable body 6 shown in FIG. 7 as viewed from below. As is apparent from FIG. 8, the groove 133 is formed so that the rotation angle of the second movable body 6 is restricted. In the example of FIG. 8, the groove 1 is formed so that the second movable body 6 is rotatable within a range of 180 °.
33 are formed.

The procedure for rotating the magnetic circuits 12 a and 12 b is as follows. First, the carriage 4 is moved further outward than the outermost periphery of the disk 1 and provided on the intermediate gear 131 provided on the carriage 4 and the base 2. And the driving gear 132 of the driving motor. Then, the second movable body 6 is rotated via the intermediate gear 131 by rotating the drive gear 132 with the drive motor. As a result, the magnetic circuits 12a and 12b are rotated by 180 °, and the objective lens to be used is replaced.

As described above, according to the third embodiment, since the driving force from the driving gear 132 is transmitted to the second movable body 6 via the intermediate gear 131, the driving gear 13
2 does not directly press the second movable body 6 to tilt the rotating shaft 7. Therefore, according to the third embodiment, not only the same effect as in the first embodiment can be obtained, but also a practical effect that deterioration of the reproduction signal due to the inclination of the axis can be prevented. is there.

(Fourth Embodiment) Next, an information recording / reproducing apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. In addition, about the same component as 1st Embodiment mentioned above,
The same reference numerals are given and duplicate descriptions are omitted.

The fourth embodiment (FIG. 9) is different from the third embodiment (FIG. 6) in a mechanism for applying a rotational driving force to the intermediate gear 131 to switch between the objective lenses 8a and 8b. In the third embodiment, the intermediate gear 131 is used.
A drive gear 132 and a drive motor for rotating the drive gear are employed as a mechanism for applying a rotational drive force to the drive shaft. On the other hand, in the fourth embodiment, a rack 134 for contacting and rotating the intermediate gear 131 is employed. Is done.

That is, in order to rotate the magnetic circuits 12a and 12b, the rack 134 fixed to the base 2 was provided on the carriage 4 in the process of moving the carriage 4 further outside the outermost periphery of the disk 1. An operation is performed so as to press against the intermediate gear 131. As a result, the intermediate gear 131 against which the rack 134 is pressed rotates with the movement of the carriage 4, and rotates the magnetic circuits 12a and 12b. Conversely, in order to return the rotated magnetic circuits 12a and 12b to their original positions, the rack 134 is moved to the intermediate gear 131 in the process of moving the carriage 4 to the inner peripheral side of the disk 1.
It is sufficient to operate so as to press against.

By employing such a method, the rotation angles of the magnetic circuits 12a and 12b can be arbitrarily changed according to the amount of movement of the carriage 4. As described above, according to the fourth embodiment, not only the same effects as in the third embodiment can be obtained, but also the second movable body 6 (including the magnetic circuits 12a and 12b) is rotated. This eliminates the need for expensive equipment, such as a motor, and has the practical effect of reducing manufacturing costs.

It should be noted that the present invention is not limited to the above-described embodiments, and can be implemented with various modifications without departing from the scope of the invention. For example, when rotating the second movable body 6 in each embodiment, it is not necessary to rotate the entire magnetic circuits 12a and 12b, and only the yokes 11c and 11d may be rotated.
That is, by rotating only the yokes 11c and 11d, the yokes 11a and 11b that are magnetically attracted to the yokes 11c and 11d also automatically rotate, and as a result, the first movable body 5 is moved. Rotate. In addition,
In this case, it is preferable that the yokes 11a and 11b are rotatably attached to the rotating shaft 7.

Further, it is of course possible to replace the flexible printed circuit board 107 in each of the above embodiments with a lead wire. Further, the present invention is not limited to application to an objective lens driving device, but can also be applied to an information recording / reproducing device having a plurality of heads (for example, a magnetic disk device having a plurality of magnetic heads). It is.
That is, a plurality of heads can be attached to the first movable body instead of the plurality of objective lenses.

In each of the above embodiments, an information recording / reproducing apparatus capable of performing both recording and reproduction has been described. However, the present invention is not limited to this, and performs either recording or reproduction. It goes without saying that the present invention can be applied to an information recording device and an information reproducing device.

In the third and fourth embodiments, the magnetic circuits 12a and 12b are rotated while the carriage 4 is moved outside the outermost periphery of the disk 1 (outside the recording area). For example, the magnetic circuits 12a and 12b can be rotated using the driving force of the spindle motor 3 inside the recording area of the disk 1. In this case, the spindle motor 3 and the second movable body 6 are formed so as to mesh with each other so that the rotational force of the spindle motor 3 is transmitted to the magnetic circuits 12a and 12b. It is necessary that the range of the rotatable angle is within 180 degrees.

[0084]

As described above in detail, according to the present invention, 1
A plurality of objective lenses (or heads) are mounted on one device, and these objective lenses and the like are controlled so that they can be appropriately switched according to the type of information storage medium (optical disk or magneto-optical disk) arranged. You. for that reason,
It is possible to record / reproduce not only the conventional standard optical disk and magneto-optical disk but also the new standard optical disk and magneto-optical disk with one apparatus. That is, it is possible to realize recording / reproducing of a plurality of optical disks and magneto-optical disks having different standards and characteristics by one apparatus.

In particular, according to the present invention, a magnet (a part of a magnetic circuit) for rotationally driving the first movable body on which the objective lens is mounted is attached to the second movable body. It is characterized in that it is configured to be able to rotate around a central axis. Therefore, since the inclination of the movable body with respect to the rotation axis does not change, if the optical axes of a plurality of objective lenses are adjusted so that they coincide when assembling the apparatus, any one of the objective lenses can be used when the apparatus is driven. It is also possible to realize a good recording / reproducing operation without generating coma or the like.

Further, since the relative position between the first movable body and the second movable body hardly changes even if the second movable body rotates, the lead wire or the like is moved from the first movable body to the second movable body. By relaying and connecting to the outside, it is possible to realize a good recording / reproducing operation without danger such as the lead wire being cut.

[Brief description of the drawings]

FIG. 1 is a plan view showing the configuration of an information recording / reproducing device (optical disc device) according to a first embodiment of the present invention.

FIG. 2 is a plan view showing the structure of an objective lens driving device incorporated in the optical disk device shown in FIG.

FIG. 3 is a sectional view showing a structure of an objective lens driving device incorporated in the optical disc device shown in FIG. 1;

FIG. 4 is a diagram showing an optical processing system and a signal processing system of the optical disk device shown in FIG.

FIG. 5 is a plan view showing a configuration of an information recording / reproducing device (optical disc device) according to a second embodiment of the present invention.

FIG. 6 is a plan view showing the configuration of an information recording / reproducing device (optical disc device) according to a third embodiment of the present invention.

FIG. 7 is a sectional view showing a structure in a state where the second movable body and the intermediate gear are fitted in the objective lens driving device shown in FIG. 6;

FIG. 8 is a plan view showing a state where a groove is formed in the second movable body shown in FIG. 7;

FIG. 9 is a plan view showing the configuration of an information recording / reproducing device (optical disc device) according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Disk, 2 ... Base, 3 ... Spindle motor, 4 ... Carriage, 4a ... Fixed part, 5 ... First movable body, 5a ... Blade, 5b ... Coil bobbin, 5c ... Sliding bearing, 6 ... Second movable body 6a: sliding bearing, 7: rotary shaft, 8a, 8b: objective lens, 9a, 9b: focus coil, 10a, 10b: permanent magnet, 11a to 11d: yoke, 12a, 12b: magnetic circuit, 13a, 13b: radial Coil, 14a, 14b radial magnetic circuit, 15a, 15b back yoke, 16a, 16b center yoke, 17a, 17b permanent magnet, 18a, 18b guide rail, 19a, 19b slide bearing, 20 optical unit, Reference numeral 21: semiconductor laser, 22: collimating lens, 23a, 23b: beam splitter, 24a, 24b ... Focusing lens, 25a, 25b photodetector, 26 control unit, 27 track control circuit, 28 focus control circuit, 29 information reproduction circuit, 30 recording signal generation circuit, 31 objective lens switching circuit, 32a, 32b: stopper, 41: optical path, 100a, 100b: tracking coil, 101a, 101b: permanent magnet, 102: first spacer ring, 103: second spacer ring, 104a to 104d: first terminal, 105a to 105d ... second terminals, 106a-106d ... lead wires, 107 ... flexible printed circuit boards, 108,132 ... drive gears (pinions), 109 ... racks, 110a, 110b ... magnetic bodies, 121,122 ... projections, 123,124 ... Lever, 131: Intermediate gear (pinion), 133: Groove 134 ... stopper pin.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Naomasa Takahashi 70, Yanagicho, Saiwai-ku, Kawasaki-shi, Kanagawa Pref. JP-A-138265 (JP, A) JP-A-8-315408 (JP, A) JP-A-58-69812 (JP, U) JP-A-64-24521 (JP, U) (58) Fields investigated (Int. .7, DB name) G11B ^7/ 08-7/22

Claims (9)

(57) [Claims] A carriage movable on the optical information recording medium; a rotating shaft erected on the carriage; a first movable body rotatable around the rotating shaft; and a first movable body. A plurality of objective lenses provided on a body, having different optical characteristics; a plurality of objective lenses rotatable around the rotation axis; attracting the first movable body by magnetic force; and rotatable with the first movable body. And the first and second movable bodies are rotated and positioned so that a light beam is guided to the optical information recording medium through a desired objective lens among the plurality of objective lenses. And a drive section for selectively rotating and positioning one of the objective lenses. 2. The apparatus according to claim 1, further comprising a magnetic body attached to said first movable body, and a magnet attached to said second movable body for attracting said first movable body. Item 2. The objective lens driving device according to Item 1. 3. The objective lens driving device according to claim 1, further comprising a coil attached to said first movable body for receiving a current for rotating said first movable body. 4. The apparatus according to claim 3, further comprising a lead wire connected to the outside via the first movable body to the second movable body and for supplying a current to the coil. Objective lens driving device. 5. The objective lens driving device according to claim 1, wherein the first movable body is formed such that its center of gravity is located on the rotation axis. 6. The objective lens driving device according to claim 1, wherein each of the plurality of objective lenses has a different numerical aperture. 7. The objective lens driving device according to claim 1, wherein the carriage is configured to be able to move outside the optical information recording medium. 8. A carriage movable on an optical information recording medium, a rotating shaft erected on the carriage, a first movable body rotatable around the rotating shaft, and the first movable body. A plurality of optical elements of different standards provided on the body; a second movable element rotatable around the rotation axis, attracting the first movable element by magnetic force, and rotatable together with the first movable element. The first and second movable bodies are rotated and positioned so that data is recorded on the optical information recording medium by a desired one of the plurality of optical elements . An information recording apparatus, comprising: a drive unit for selectively rotating and positioning one of the optical elements . 9. A carriage movable on an optical information recording medium, a rotating shaft erected on the carriage, a first movable body rotatable around the rotating shaft, and the first movable body. Multiple lights of different standards provided on the body
And Manabu element is rotatable around the rotary shaft, the desired one of the second movable body of the first movable body rotatable together with the attracted by the magnetic force the first movable member, said plurality of optical elements Selectively rotating one of the plurality of optical elements by rotating and positioning the first and second movable bodies so that the optical element reproduces data from the optical information recording medium. An information reproducing apparatus, comprising: a driving unit for rotating and positioning.