JPH08212574A - Objective lens driving device, information recorder and information reproducing device - Google Patents

Abstract

PURPOSE: To record/reproduce plural disks with standards and characteristics different from each other by one objective lens driving device. CONSTITUTION: A first movable body 5 loads two pieces of objective lenses 8a, 8b. Magnetic circuits 12a, 12b actuating magnetic field to tracking coils 100a, 100b stuck to the first movable body 5 are fixed to a second movable body 6. The first movable body 5 and the second movable body 6 are rotatable around a rotary shaft 7. By controlling so as to properly switch these objective lenses 8a, 8b according to the kinds of the arranged disks, the disks with different characteristics are recorded/reproduced by one device. Further, since it is eliminated that the slope of the first movable body 5 for the rotary shaft 7 changes, the probability that coma aberration, etc., occurs is eliminated even when either one of objective lenses 8a, 8b is used and recording/reproducing operation is performed excellently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention 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, along with the development of optical information recording media such as optical discs and magneto-optical discs, objective lens driving devices used for reproducing devices of these optical information recording media have been actively developed. The objective lens driving device is already widely used as a CD-ROM represented by a compact disc (CD) and a laser disc (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 system such as an MO (Magnet-optical) system or a PC (Phase-Change) system has been developed. Are known.

[0004]

Generally, the recording structure of an optical disc or a magneto-optical disc is defined by a standard. However, it is expected that the recording density will improve with the passage of time. For example, the size of a pit, which is a unit in which information is recorded, is likely to reach submicron from the current 1 micron.

In order to achieve this, the wavelength of the laser light used is shortened, and the NA (Number
The device side has been devised to increase the numerical aperture) to reduce the spot diameter of the light beam.

Discs having different substrate thicknesses are also emerging as a new standard, and there is a risk that the new device will not be able to record or reproduce information on the discs of the conventional standard.

Since a plurality of devices must be prepared in order to be compatible with discs of any standard, there is a problem that cost is high and efficient recording / reproducing processing cannot be performed. There is.

Therefore, it is desired that not only conventional optical disks and magneto-optical disks but also new standard optical disks and magneto-optical disks can be recorded / reproduced by one device.

The present invention has been made in view of the above circumstances, and the present invention is an objective lens driving device capable of performing recording / reproducing of a plurality of optical disks or magneto-optical disks having different standards and characteristics with a single device. , An information recording device and an information reproducing device are provided.

The present invention also provides an objective lens driving device, an information recording device and an information reproducing device for realizing a good recording / reproducing operation without causing coma aberration when recording / reproducing an optical disc or a magneto-optical disc. The purpose is to provide a device.

Further, according to the present invention, an objective lens driving device which realizes a good recording / reproducing operation without danger such as cutting of a lead wire when recording / reproducing an optical disc or a magneto-optical disc with one device. , An information recording device and an information reproducing device are provided.

[0012]

In order to achieve the above object, an objective lens driving device according to the present invention comprises a carriage movable on an optical information recording medium, and a rotary shaft erected on the carriage. A first rotatable about the rotation axis
Of the movable body, a plurality of objective lenses provided on the first movable body and having different optical characteristics, a second movable body rotatable about the rotation axis, and a plurality of the objective lenses. Of these, a driving unit for rotating and positioning the first and second movable bodies to a predetermined position so that the light beam is guided to the optical information recording medium through a desired objective lens is provided.

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

Further, it is desirable that a coil capable of passing an electric current is attached to the first movable body in order to control the drive of 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.

Further, it is desirable that the first movable body is formed so that its center of gravity is located on the rotation axis. Further, it is preferable that the carriage is configured to be able to move 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 drive is
It is preferable to provide 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 is provided with the second
It is desirable that an intermediate gear meshing with the movable body of is attached. In this case, it is preferable that the drive unit 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 to the outside of the optical information recording medium.

In order to achieve the above object, the information recording apparatus according to the present invention has a carriage movable on an optical information recording medium, a rotary shaft erected on the carriage, and a rotary shaft of the rotary shaft. A first movable body rotatable around the plurality of optical elements of different standards provided on the first movable body; a second movable body rotatable around the rotation axis; A driving unit that rotates and positions the first and second movable bodies to predetermined positions so that data can be recorded on the optical information recording medium by a desired one of the optical elements. It is characterized by

In order to achieve the above object, the information reproducing apparatus according to the present invention has a carriage movable on an optical information recording medium, a rotary shaft erected on the carriage, and a rotary shaft of the rotary shaft. A first movable body rotatable around the plurality of optical elements of different standards provided on the first movable body; a second movable body rotatable around the rotation axis; A driving unit that rotates and positions the first and second movable bodies to a predetermined position so that data can be reproduced from the optical information recording medium by a desired one of the optical elements. It is characterized by

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

Further, it is desirable that a coil capable of passing a current is attached to the first movable body for drive control of 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.

Further, it is desirable that the first movable body is formed so that its center of gravity is located on the rotation axis. It is desirable that each of the plurality of objective lenses has a different numerical aperture.

It is desirable that the carriage is constructed so as 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 drive unit includes a lever that comes into contact with the second movable body so that the second movable body is rotated in a process in which the carriage moves to the outside of the optical information recording medium. .

In addition, the carriage is provided with the second
It is desirable that an intermediate gear meshing with the movable body of is attached. In this case, it is preferable that the drive unit 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 to the outside of the optical information recording medium.

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

In particular, according to the present invention, a magnet (a part of a magnetic circuit) for rotationally driving the first movable body carrying these objective lenses is attached to the second movable body, and the second movable body is It is characterized in that it can be rotated around the central axis. Therefore, the inclination of the movable body with respect to the rotation axis does not change, so if the optical axes of the multiple objective lenses are adjusted to match when assembling the device, whichever objective lens is used when driving the device. In addition, it is possible to realize a good recording / reproducing operation without causing coma aberration and the like.

Further, since the relative position between the first movable body and the second movable body hardly changes even when 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 disconnection of the lead wire.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) First, a first embodiment of the information recording / reproducing apparatus of 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 type 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 cross-sectional view of the objective lens driving device, and FIG. It is a figure which shows an optical processing system and a signal processing system.

As shown in FIG. 1, a disc 1 (optical disc, magneto-optical disc, etc.) used 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 driven to rotate by the spindle motor 3 during recording and reproduction.

A carriage 4 is arranged near the lower portion of the disk 1. A first movable body 5 and a second movable body 6 are mounted on the carriage 4. As will be described later, the first movable body 5 is movably supported in the radial direction and the thickness direction of the disc 1, and the second movable body 6 is movably supported only in the radial direction of the disc 1. . That is, both the first and second movable bodies 5 and 6 can be rotationally moved around their axial centers.

As shown in FIG. 3, the first movable body 5 comprises a flat blade 5a facing the surface of the disk 1 and a tubular coil bobbin 5b fixed to the lower portion of the blade 5a. In addition, these blade 5a and coil bobbin 5
A slide bearing 5c is provided at the center of b.

A rotary shaft 7 having one end fixed to a fixed portion (non-rotating portion) 4a of the carriage 4 is vertically inserted into the slide bearing 5c through a minute gap (10 microns or less).
It constitutes a plain 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.

On the blade 5a, a plurality of, here two, objective lenses 8a and 8b are fixed separately. These objective lenses 8a and 8b have different optical characteristics (for example, the numerical aperture (NA) of the objective lens 8a is 0.45).
Then, 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 entire mass of the first movable body 5 substantially coincides 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 rotation shaft 7 by the two objective lenses 8a and 8b.

As shown in FIG. 2, on the side surface of the coil bobbin 5b, two planarly wound rectangular focus coils 9a and 9b are similarly provided. Two tracking coils 100a and 100b
Is affixed. Two focus coils 9a and 9b
Are attached at positions symmetrical with respect to the rotating shaft 7, and the two tracking coils 100a and 10a are provided.
Similarly, 0b is also attached at a position symmetrical with respect to the rotating shaft 7.

Then, these focus coils 9a, 9
b and around the tracking coils 100a, 100b and on the second movable body 6, the permanent magnets 10a, 10b, 1 are arranged in a symmetrical positional relationship with respect to the rotation axis 7.
Magnetic circuits 12a and 12b, each of which includes 01a and 101b and yokes 11a to 11d, are provided. As shown in FIG. 2, the focus coils 9a and 9b and the tracking coils 100a and 100b are composed of permanent magnets 10a and 10b.
b, 101a, 101b and the yokes 11c, 11d are sandwiched between them, and they are opposed to each other with a magnetic gap of a predetermined length. And the permanent magnets 10a, 1
0b is the focus coils 9a and 9b, while the permanent magnets 101a and 101b are the tracking coils 100a and 1b.
A magnetic field is applied to each of 00b.

The yokes 11a to 11d forming the magnetic circuits 12a and 12b are fixed on the second movable body 6 by means such as welding or caulking. Here, the permanent magnets 10a and 10b have their magnetizing directions aligned with the axial direction of the rotating shaft 7, and the permanent magnets 101a and 101b are magnetized in a direction orthogonal to the magnetizing directions of the permanent magnets 10a and 10b. Is consistent with. In addition, the two magnetic circuits 12a and 12
b has the same structure.

Then, the focus coils 9a and 9b
Is energized and receives a magnetic flux from the permanent magnets 10a and 10b to generate a Lorentz force, and the first movable body 5 is finely translated in the thickness direction of the disk 1 (axial direction of the rotary shaft 7). . In addition, the tracking coils 100a and 100b are energized and the permanent magnet 10 is
Lorentz force is generated by receiving the magnetic flux from 1a and 101b, and the first movable body 5 is finely rotated in the radial direction of the disk 1 (around the rotation axis 7).

Further, two magnetic bodies 110a and 110b made of iron pieces or the like are provided at the centers (hollow parts in a wound state) of the tracking coils 100a and 100b attached to the side surfaces of the coil bobbin 5b. These magnetic materials 1
10a and 110b are attached at positions symmetrical with respect to the rotation axis 7. When any of the objective lenses 8a and 8b is in the optical path 24 (described later), these magnetic bodies 110a and 110b are just used as the permanent magnets 101a and 101b of the magnetic circuits 12a and 12b and the yokes 11c and 11d. It becomes a sandwiched relationship.

As shown in FIG. 3, a slide bearing 6a is provided at the center of the second movable body 6 so as to fit with the rotary shaft 7. The plain bearing 6a is inserted and fitted into the rotary shaft 7 through a minute gap (10 microns or less), and constitutes a plain bearing mechanism which allows only rotation. Therefore, the second movable body 6 can rotate independently of the first movable body 5. Further, 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 rotary shaft 7. To do.

The slide bearing 6a is fixed to the second movable body 6 by means of ultrasonic welding, heat welding, or adhesion. As shown in FIG. 3, an elastic body (for example, a spring coil or a coil spring) or a viscoelastic body (for example, a spring coil or a coil spring) is provided 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 friction coefficient than the first spacer ring 102 are laminated and arranged. The first spacer ring 102 is fixed to the slide bearing 6a,
The spacer ring 103 is arranged opposite to the second plain bearing 5c. The friction coefficient between the second spacer ring 103 and the second slide bearing 6a is preferably set to, for example, 0.4 or less, and thereby it is possible to prevent both from adsorbing.

Further, 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 105a on the magnetic circuit 12a are provided. 105b is connected via lead wires 106a and 106b. Similarly, the first terminals 104c and 104d connected to the tracking coils 100a and 100b are provided, and the 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.

Flexible printed circuit boards 107 are connected between the second terminals 105a to 105d on the magnetic circuits 12a and 12b and an external power source (not shown). Flexible printed circuit board 10
As the member 7, a member longer than half the outer peripheral length of the second movable body 6 is adopted, and as shown in FIG. 2, it is arranged in a substantially U-shaped curved state. .

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

The radial magnetic circuits 14a and 14b include back yokes 15a and 15b and center yokes 16a and 16b.
b and permanent magnets 17a and 17b, the radial coils 13a and 13b are center yokes 16a and 16b.
It is movably inserted into a magnetic gap defined by b and the permanent magnets 17a and 17b. The two radial magnetic circuits 14a and 14b have the same structure, and the magnetizing directions of the permanent magnets 17a and 17b coincide with the thickness direction of the magnetic gap.

Two to four plain bearings 19a and 19b are provided on the left and right of the fixed portion 4a of the carriage 4 (see FIG. 2).
2), the two guide rails 18a and 18b are arranged in parallel so as to be inserted into these plain 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
It is movably supported along 8b.

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

The magnetic gap width of the radial magnetic circuits 14a and 14b is such that the second movable body 6 has a guide rail 18a.
a so that the objective lenses 8a and 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.
Is long enough to move the objective lenses 8a and 8b mounted on the carriage 4 to the outside of the outermost circumference of the recording area of the disk 1. Then, when the carriage 4 moves to the outside of 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 portion of the second movable body 6 in a rack ( Gear train) 109 (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, the optical system and signal processing system of this apparatus will be described. As shown in FIG. 4, the laser light for irradiating the disc 1 is generated by the optical unit 20 which is fixed to the lower part of the movable body 4 and is 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, bent by 90 ° by the first beam splitter 23a, and then the inside of the carriage 4 from the radial direction of the disc 1. Be 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 is incident on the objective lens 8 (8a or 8b) through the optical path 41. . The laser beam LB incident on the objective lens 8 is given a predetermined focusing property and is focused on the information storage surface of the disc 1.

Here, when the system is in the information reproducing state, the laser beam LB guided to the disc 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 light LB returned to the objective lens 8 has an optical path 41.
It is guided through the inside to the fixed optical unit 20 again. Then, it passes through the first beam splitter 23a, is split into two paths by the second beam splitter 23b, and is passed through the focusing lenses 24a and 24b respectively to the first photodetector 2
An image is formed on 5a and the second photodetector 25b.

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

By using the focus offset signal and the track offset signal, the positional deviation (focus deviation) of the objective lens 8 in the focusing direction is detected, and the current value given to the focus coils 9a and 9b is controlled so as to correct this positional deviation. To be done. Further, the track offset signal is used to detect the positional deviation of the objective lens 8 in the track direction, and the current value given to the tracking coils 100a and 100b is controlled so as to correct the positional deviation.

The reflected laser light 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 disc 1, and is sent to a host system (for example, a personal computer or the like) (not shown) to be displayed as characters or still images or moving images, or music from a speaker. It is output as voice. In this case, carriage 4
Is controlled to follow the tracks on the information storage surface of the disk 1 in the radial direction of the disk 1 by a large drive or a minute drive.

In the control unit 26, there are provided a recording signal generating circuit 30 for generating a recording signal according to information input from an external host system (not shown) (for example, a personal computer), and the objective lenses 8a and 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 placed in the optical path 24 of the laser light LB described above.

Next, the switching mechanism of 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 type of disc as in the conventional case, and a plurality of discs having different standards such as disc recording density, warp tolerance, disc substrate thickness, etc. Different types of discs are available. For example, C
Not only D-ROM discs but also MO discs, PC discs, etc. can be used. As the two objective lenses 8a and 8b, those adapted to the processing of usable discs are prepared.

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

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

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

First, by receiving a signal from the objective lens switching circuit 31, the carriage 4 is driven and moved further outside the outermost circumference of the disk 1. Then, as shown in FIG. 1, the drive gear 108 of the drive motor fixed to the base 2 and the rack 109 are engaged with each other.
When a rotational force is applied by the drive motor after detecting a state in which the two are in mesh, 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, as described above, the two magnetic bodies 110a and 110b are attached to the first movable body 5. Therefore, the first movable body 5 is provided with these magnetic bodies 110a, 1a.
10b is just the permanent magnet 1 of the magnetic circuits 12a and 12b.
In the state of being sandwiched between 01a, 101b and the yokes 11c, 11d, the attraction force is maximized and magnetically stable. That is, as described above, the magnetic circuits 12a, 12
By adopting the structure of rotating b, the first movable body 5 is magnetically attracted and the permanent magnets 101a, 101b are
Will rotate with. For example, the second movable body 6
Is rotated by 180 °, the first movable body 5 can be automatically rotated by 180 °. In this way, the objective lenses 8a and 8b can be switched.

When the desired objective lens corresponding to the mounted disk 1 is already present on the optical path 41, it is not necessary to rotate the second movable body 6. As described above, according to the first embodiment, the two objective lenses can be switched and used according to the standard or specification of the disc, and therefore, it is possible to use a dedicated (separate It is not necessary to prepare a plurality of objective lens driving devices. Therefore, an objective lens driving device that can handle various kinds of information satisfactorily with only one device is provided.

Further, according to the first embodiment, since the rotary 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 to be substantially coincident with each other when the device is assembled, coma aberration or the like may occur regardless of which objective lens 8a or 8b is used for driving the device. Therefore, the recording / reproducing operation can be performed well.

Further, the first movable body 5 and the magnetic circuit 12a,
The relative position to 12b (the second movable body 6) only changes by a few degrees when the first movable body 5 is driven to rotate slightly. Because of this, 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, so that the objective lens 8
Even in a situation where it is necessary to rotate a and 8b by 180 °, there is a great practical effect that the risk of cutting the lead wires 106a to 106d is 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, regarding the same components as those in the first embodiment,
The same reference numerals are given and duplicate explanations are omitted.

The second embodiment (FIG. 5) is different from the first embodiment (FIG. 1) described above in the specific method for switching the objective lenses 8a and 8b. In the first embodiment described above, the drive gear 108 and the drive motor that rotates the drive gear are adopted, whereas in the second embodiment, the first protrusion 121, the second protrusion 122, and the first protrusion 121 are used. The lever 123 and the second lever 124 are adopted.

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

In order to rotate the magnetic circuits 12a and 12b in the opposite directions, the second protrusion 122 projecting from the second movable body 6 has a second lever 124 whose one end is fixed to the base 2. It may be contacted with.

The first lever 123 may be added with a spring function. That is, the first lever 1
When the magnetic circuits 12a and 12b are rotated about 90 ° by bringing 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, a cam (not shown) or the like is used to retract the second lever 124 in the A direction to a position where collision with the second protrusion 122 is avoided. On the contrary, the magnetic circuit 1
When rotating 2a and 12b, a cam (not shown) or the like is used to move the first lever 123 to the first protrusion 12 this time.
Evacuate in the direction A to a position where collision with 1 is avoided.

As described above, according to the second embodiment, the same effect as in the first embodiment can be obtained, and the second movable body 6 (the magnetic circuits 12a and 12b) can be obtained.
It is not necessary to use expensive equipment such as a motor for rotating the magnetic circuits 12a and 12b for rotating the magnetic circuit 12a and 12b, and the manufacturing cost can be reduced.

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

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

That is, in the third embodiment, the intermediate gear 131 fitted to the second movable body 6 is provided in the carriage 4 main body, and the drive gear 132 and the drive gear 1 are provided.
A drive motor for rotating 32 is installed on the base. The 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 to the outside of the outermost circumference of the disc 1,
The intermediate gear 131 is adapted to mesh with the drive gear 132 of the 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.
It is sectional drawing which shows the structure of the objective-lens drive device in the state with which and were fitted. As shown in the figure, the second movable body 6 includes
A groove 133 is provided. Further, a stopper pin 134 is provided upright at one end of a fixed portion (non-rotating portion) of the carriage 4, and the stopper pin 134 is in a state of being engaged with the groove portion 133. Here, the stopper pin 13
4 is provided on a straight line that connects the rotation shaft 7 and the center of rotation of the intermediate gear 131.

FIG. 8 is a plan view of the second movable body 6 shown in FIG. 7 as seen from below. As is clear 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 portion 1 is provided so that the second movable body 6 can rotate within a range of 180 °.
33 are formed.

As a procedure for rotating the magnetic circuits 12a and 12b, first, the carriage 4 is moved further outward than the outermost circumference of the disk 1 and is provided on the intermediate gear 131 and the base 2 provided on the carriage 4. The drive gear 132 of the drive motor thus obtained is engaged. Then, the drive gear 132 is rotated by the drive motor to rotate the second movable body 6 via the intermediate gear 131. As a result, the magnetic circuits 12a and 12b rotate by 180 °, and the objective lens to be used is replaced.

As described above, according to the third embodiment, the driving force from the driving gear 132 is transmitted to the second movable body 6 via the intermediate gear 131, so that the driving gear 13
There is no case in which 2 presses the second movable body 6 directly and tilts the rotating shaft 7. Therefore, according to the third embodiment, not only the same effects as in the first embodiment can be obtained, but also the practical effect that the deterioration of the reproduced signal due to the tilt of the axis can be prevented. is there.

(Fourth Embodiment) Next, a fourth embodiment of the information recording / reproducing apparatus of the present invention will be described with reference to FIG. In addition, regarding the same components as those in the first embodiment,
The same reference numerals are given and duplicate explanations are omitted.

The fourth embodiment (FIG. 9) is different from the above-described third embodiment (FIG. 6) in the mechanism for applying the rotational driving force to the intermediate gear 131 in order to switch the objective lenses 8a and 8b. In the above-described third embodiment, the intermediate gear 131
While the drive gear 132 and the drive motor for rotating the drive gear are adopted as the mechanism for applying the rotational drive force to the rack, the rack 134 for contacting the intermediate gear 131 and rotating the same is adopted in the fourth embodiment. To be done.

That is, in order to rotate the magnetic circuits 12a and 12b, the rack 134 fixed to the base 2 is provided on the carriage 4 in the process of moving the carriage 4 further outside the outermost periphery of the disk 1. It is operated so as to be pressed against the intermediate gear 131. As a result, the intermediate gear 131, to 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.
Just press it against.

By adopting such a method, the rotation angles of the magnetic circuits 12a and 12b can be arbitrarily changed according to the movement amount of the carriage 4. As described above, according to the fourth embodiment, the same effect as in the third embodiment can be obtained, and the second movable body 6 (including the magnetic circuits 12a and 12b) is rotated. There is a practical effect in that expensive equipment such as the motor is unnecessary and the manufacturing cost can be reduced.

It is needless to say that the present invention is not limited to each of the above-described embodiments, and can be variously modified and implemented 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 in a magnetically attracted relationship with the yokes 11c and 11d also automatically rotate, and as a result, the first movable body 5 moves. Rotate. In addition,
In this case, it is preferable that the yokes 11a and 11b be rotatably attached to the rotary 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 the application to the objective lens driving device, but can 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). Is.
That is, it is possible to attach a plurality of heads to the first movable body instead of a plurality of objective lenses.

In each of the above embodiments, the information recording / reproducing apparatus capable of both recording and reproducing has been described, but the present invention is not limited to this, and either recording or reproducing is performed. It goes without saying that it 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 to the outside of the outermost circumference of the disk 1 (outside the recording area). For example, the magnetic circuits 12a and 12b can be rotated by utilizing the driving force of the spindle motor 3 located 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 to keep the range of the rotatable angle of 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 are controlled so that they can be switched appropriately according to the type of information storage medium (optical disk or magneto-optical disk) in which they are arranged. It for that reason,
It becomes possible to record / reproduce not only the optical disc and the magneto-optical disc of the conventional standard but also the optical disc and the magneto-optical disc of the new standard by one device. That is, it is possible to realize recording / reproducing of a plurality of optical discs or magneto-optical discs having different standards and characteristics with one device.

In particular, according to the present invention, a magnet (a part of a magnetic circuit) for rotationally driving the first movable body mounting these objective lenses is attached to the second movable body, and the second movable body is It is characterized in that it can be rotated around the central axis. Therefore, the inclination of the movable body with respect to the rotation axis does not change, so if the optical axes of the multiple objective lenses are adjusted to match when assembling the device, whichever objective lens is used when driving the device. In addition, it is possible to realize a good recording / reproducing operation without causing coma aberration and the like.

Further, since the relative position between the first movable body and the second movable body hardly changes even when 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 disconnection of the lead wire.

[Brief description of drawings]

FIG. 1 is a plan view showing the configuration of an information recording / reproducing apparatus (optical disk apparatus) 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 disc device shown in FIG.

3 is a sectional view showing the structure of an objective lens driving device incorporated in the optical disc device shown in 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 the configuration of an information recording / reproducing apparatus (optical disk apparatus) according to the 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.

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

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

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 ... 1st movable body, 5a ... Blade, 5b ... Coil bobbin, 5c ... Sliding bearing, 6 ... 2nd movable body , 6a ... Sliding bearing, 7 ... Rotating shaft, 8a, 8b ... Objective lens, 9a, 9b ... Focus coil, 10a, 10b ... Permanent magnet, 11a-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 ... Sliding bearing, 20 ... Optical unit, 21 ... Semiconductor laser, 22 ... Collimating lens, 23a, 23b ... Beam splitter, 24a, 24b ... Focusing lens, 25a, 25b ... Photodetector, 26 ... Control section, 27 ... Track control circuit, 28 ... Focus control circuit, 29 ... Information reproducing circuit, 30 ... Recording signal generating 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-104d ... First terminal, 105a-105d ... second terminal, 106a to 106d ... lead wire, 107 ... flexible printed circuit board, 108, 132 ... drive gear (pinion), 109 ... rack, 110a, 110b ... magnetic material, 121, 122 ... projection, 123, 124 ... Lever, 131 ... Intermediate gear (pinion), 133 ... Groove 134 ... stopper pin.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naomasa Takahashi 70 Yanagi-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Toshiba Yanagimachi factory

Claims (34)

[Claims] 1. A carriage movable on an optical information recording medium, a rotary shaft erected on the carriage, a first movable body rotatable about the rotary shaft, and a first movable body. The plurality of objective lenses having different optical characteristics provided on the body, the second movable body rotatable around the rotation axis, and the optical information recording through a desired objective lens of the plurality of objective lenses. An objective lens driving device comprising: a driving unit that rotates and positions the first and second movable bodies to a predetermined position so that a light beam is guided to a medium. 2. A magnetic body is attached to the first movable body, and a magnet that produces an attractive force to the magnetic body is attached to the second movable body. Objective lens driving device. 3. The objective according to claim 1, wherein the first movable body is attached with a coil capable of passing an electric current for drive control of the first movable body. Lens drive device. 4. The objective according to claim 3, wherein 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. Lens drive 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 movable to the outside of the optical information recording medium. 8. 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. The objective lens driving device according to claim 7. 9. The drive 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. The objective lens driving device according to claim 7, wherein 10. The objective lens driving device according to claim 7, wherein an intermediate gear meshing with the second movable body is attached to the carriage. 11. The drive unit 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. The objective lens driving device according to claim 10. 12. The drive unit is provided with a lever that comes into contact with the intermediate gear so that the intermediate gear is rotated when the carriage moves to the outside of the optical information recording medium. Item 10. The objective lens driving device according to item 10. 13. A carriage movable on an optical information recording medium, a rotary shaft erected on the carriage, a first movable body rotatable around the rotary shaft, and the first movable body. A plurality of optical elements of different standards provided on the body; a second movable body rotatable about the rotation axis; and a desired optical element of the plurality of optical elements for applying the optical information recording medium. An information recording apparatus, comprising: a drive unit that rotates and positions the first and second movable bodies to a predetermined position so that data can be recorded. 14. A magnetic body is attached to the first movable body, and a magnet that produces an attractive force to the magnetic body is attached to the second movable body. Information recording device. 15. The information according to claim 13, wherein the first movable body is attached with a coil capable of passing an electric current for drive control of the first movable body. Recording device. 16. The information according to claim 15, wherein 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. Recording device. 17. The information recording apparatus according to claim 13, wherein the center of gravity of the first movable body is located on the rotation axis. 18. The information recording apparatus according to claim 13, wherein the carriage is configured to be movable to the outside of the optical information recording medium. 19. 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. 19. The information recording device according to claim 18, wherein: 20. The drive 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. 19. The information recording device according to claim 18, characterized in that: 21. An information recording apparatus according to claim 18, wherein an intermediate gear meshed with said second movable body is attached to said carriage. 22. The drive unit 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. The information recording device according to claim 21. 23. The drive unit is provided with a lever that comes into contact with the intermediate gear so that the intermediate gear is rotated in a process of moving the carriage to the outside of the optical information recording medium. Item 21. The information recording device according to item 21. 24. A carriage movable on an optical information recording medium, a rotary shaft erected on the carriage, a first movable body rotatable around the rotary shaft, and the first movable body. A plurality of optical elements of different standards provided on the body, a second movable body rotatable about the rotation axis, and a desired optical element of the plurality of optical elements from the optical information recording medium. An information reproducing apparatus comprising: a drive unit that rotates and positions the first and second movable bodies to predetermined positions so that data is reproduced. 25. A magnetic body is attached to the first movable body, and a magnet that produces an attractive force to the magnetic body is attached to the second movable body. Information reproducing device. 26. The information according to claim 24, wherein the first movable body is provided with a coil capable of passing a current for drive control of the first movable body. Playback device. 27. The information according to claim 26, wherein 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. Playback device. 28. The information reproducing apparatus according to claim 24, wherein the first movable body is formed such that its center of gravity is located on the rotation axis. 29. An information reproducing apparatus according to claim 24, wherein said carriage is configured to be movable to the outside of said optical information recording medium. 30. 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. 30. The information reproducing apparatus according to claim 29. 31. The drive unit includes a lever that comes into contact with the second movable body so that the second movable body is rotated when the carriage moves to the outside of the optical information recording medium. 30. The information reproducing apparatus according to claim 29, wherein: 32. The information reproducing apparatus according to claim 29, wherein an intermediate gear meshing with the second movable body is attached to the carriage. 33. The drive unit 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. 33. The information reproducing apparatus according to claim 32. 34. The drive unit is provided with a lever that comes into contact with the intermediate gear so that the intermediate gear is rotated when the carriage moves to the outside of the optical information recording medium. Item 32. The information reproducing apparatus according to Item 32.