JPH11213431A - Optical pickup and optical disk device - Google Patents

Abstract

(57) [Problem] To provide a small-sized optical pickup with a simple configuration and an optical disk device provided with the optical pickup. SOLUTION: An optical pickup 1 for reproducing and / or recording a signal on at least two serially mounted optical disks 11 having a signal recording surface formed on one side, an optical block 2 for emitting a light beam, and the optical block And at least two light guiding means 3 for causing the light beam emitted from the light source to enter and guide the light from the incident portion 3b, and to emit and converge the light beam from each of the emitting portions 3a on each signal recording surface of the optical disk. The light guide means is configured to be movable between incident portions of the light guide means, and the light guide means is configured to be rotatable along the signal recording surface of each of the optical discs with the incident portion as a rotation axis. It is configured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reproducing or recording a signal on or from at least two consecutively mounted optical disks having a signal recording surface formed on one surface or at least one optical disk having a signal recording surface formed on both surfaces. The present invention relates to an optical pickup and an optical disk device provided with the optical pickup.

[0002]

2. Description of the Related Art With the recent increase in the capacity of data and programs, it is desired to increase the density of recording media. In order to respond to such a demand, a mini disk (MD), a magneto-optical disk (MO), a compact disk (CD), a CD-ROM, a CD-R,
Optical discs such as a Video CD, a laser disc (LD), and a phase change disc (PD) are mounted in multiple units, and a digital versatile disc (DVD) having signal recording surfaces formed on both sides, a DVD-ROM, a DVD-RAM, and the like. Optical discs are being developed.

A conventional optical pickup provided in an optical disc apparatus for reproducing or recording signals from a plurality of optical discs having a signal recording surface formed on one surface has a configuration arranged for each signal recording surface of each optical disc. ing.
Further, an optical pickup provided in an optical disk device for reproducing or recording a signal of an optical disk having a signal recording surface formed on both surfaces is arranged for each signal recording surface of the optical disk.

[0004]

A plurality of optical pickups provided in the above-mentioned conventional optical disk drive require a plurality of optical pickups. However, since a plurality of drive units for the optical pickups are also required, the structure becomes complicated and the cost increases. There was a problem. As an optical disk device that solves this problem, only one optical pickup is provided, a signal recording surface is formed on one side of the optical pickup, and a mechanism for transporting and exchanging necessary optical disks out of multiple optical disks, or both sides. 2. Description of the Related Art There is an optical disk device provided with a mechanism for inverting the front and back surfaces of an optical disk on which a signal recording surface is formed. However, there is a problem that a space for transporting and reversing the optical disk is required, and the optical disk device itself is enlarged.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a small-sized optical pickup having a simple configuration and an optical disk device provided with the optical pickup.

[0006]

According to the present invention, there is provided, in accordance with the present invention, at least two consecutively mounted optical disks having a signal recording surface formed on one side or at least one optical disk having a signal recording surface formed on both surfaces. An optical pickup for reproducing and / or recording a signal on an optical disk, comprising: an optical block for emitting a light beam; and a light beam emitted from the optical block, which is incident from an incident portion to guide the light, At least two light guides for emitting and converging the light from the emission unit on the signal recording surface, wherein the optical block is configured to be movable between the entrances of the respective light guides; However, this is achieved by the configuration in which the emission section is rotatable along the signal recording surface of each of the optical discs with the incidence section as a rotation axis.

Further, according to the present invention, there is provided an optical disk having at least two continuous optical disks having a signal recording surface formed on one side or at least one optical disk having a signal recording surface formed on both surfaces. An optical disc device having an optical pickup for reproducing and / or recording a light beam, wherein the optical pickup emits a light beam, and guides the light beam emitted from the optical block by entering from an incident portion. And at least two light guides for emitting and converging each signal recording surface of the optical disc from an emission unit, wherein the optical block is configured to be movable between the entrances of the respective light guides, Each of the light guide means is configured to be rotatable along the signal recording surface of each of the optical discs, with the emission section being the rotation axis of the incidence section. It is made.

According to the above arrangement, a light beam for reproducing and recording a signal can be transmitted by the light guide means disposed on each signal recording surface of the optical disk, and therefore, the light guide means can be moved between the light guide means. Only one optical block needs to be arranged, so that the configuration can be simplified and the size can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The embodiment described below is a preferred specific example of the present invention, and thus various technically preferable limitations are added. However, the scope of the present invention particularly limits the present invention in the following description. It is not limited to these forms unless otherwise stated.

FIG. 1 is a schematic block diagram showing an embodiment of the optical disk apparatus of the present invention, and FIG. 2 is a schematic perspective view showing an embodiment of the optical pickup of the present invention provided in the optical disk apparatus. . This optical disk device 1
Numeral 0 denotes a spindle motor 12 as a driving means for rotating a plurality of optical discs 11 having a signal recording surface formed on one side and rotating the optical discs 11, and irradiating an optical beam to the signal recording faces of the rotating optical discs 11 to reproduce them. The optical pickup 1 reproduces a recording signal on each signal recording surface during recording, and records a signal on each signal recording surface using a magnetic field from a magnetic field head during recording, and a control unit 13 for controlling these.

The optical pickup 1 receives one optical block 2 for emitting a light beam and a light beam emitted from the optical block 2 to guide the light beam, emits the light beam to a signal recording surface of each optical disk 11, and focuses the light. In addition, a plurality of light guide means 3 for generating a magnetic field on the signal recording surface of each optical disc 11 are provided. As shown in FIG. 2, the optical block 2 is formed in a box shape, and is arranged below and below the lowermost optical disc 11 in the figure. As shown in FIG. 2, each light guide means 3 is formed in a substantially S-shaped rod shape, and one end face 3a faces substantially the center of the signal recording surface of each optical disc 11, and each other end face 3b has The lower optical disk 11 is arranged so as to be arranged radially below and below the outermost optical disk 11. A coil-shaped magnetic field head 3e corresponding to the magnetic field modulation overwrite is wound on one end face 3a side of each light guide means 3 and is arranged along the outer periphery of the light guide means 3 from the one end face 3a side. On the side of the end face 3b, both ends of the magnetic field head 3e are provided as magnetic field head signal lines 3f.

The optical block 2 is connected to the other end face 3 of any light guide means 3 whose light beam emitting portions 2a are arranged in parallel.
The moving means (not shown) is configured to be movable in the illustrated arrow a direction so as to be able to oppose b at any time. Each light guide means 3 is rotated by a rotating means (not shown) so that each one end face 3a can perform a seek operation along the signal recording surface of each optical disc 11 about the substantially center of each other end face 3b as a rotation axis. It is configured to be rotatable in the direction.

By moving the optical block 2 having such a configuration in the direction of the arrow a in the figure, the light beam emitting portion 2a
Is emitted from the other end face 3b of an arbitrary light guide means 3, that is, an incident portion, and propagates through the light guide means 3 to be emitted from one end face 3a of the light guide means 3, that is, the emission section. As a result, the light can be focused on the signal recording surface of the corresponding optical disc 11. In addition, a magnetic field can be generated on the signal recording surface of the corresponding optical disc 11. Further, by rotating the light guide means 3 in the direction of the arrow r in the figure, signals can be recorded / reproduced on the entire signal recording surface of the corresponding optical disc 11.

The shape of the light guide means 3 is not limited to a substantially S-shape. For example, the light guide means 3 may be formed in a substantially L-shape such that the incident portion 3b of the light guide means 3 is arranged in the direction of the rotation axis of the optical disk 11. The optical block 2 is configured to be movable in the direction of the rotation axis of the optical disk 11 along the incident portion 3b of each light guide means 3, and the light guide means 3 and the optical block 2 are connected to the incident part of each light guide means 3. It may be configured to be rotatable around 3b as a rotation axis.

FIGS. 3A and 3B are a side view and a plan view showing a detailed example of the optical block 2 described above. The optical block 2 includes a semiconductor laser element 21 as a light source.
Correction plate 22a as astigmatism correction means, grating 22b as light splitting means, beam splitter 23 as light separation means, arranged in parallel in the optical path of the light beam emitted from A collimator lens 24 as a light converting means, a prism mirror 25 as a light path bending means, an objective lens 26 as a light focusing means, and a separated light path of a return light beam from the optical disk 11 reflected by the beam splitter 23 are sequentially arranged. An optical system 20 having a Wollaston prism 27 as a light splitting means, a multi-lens 28 as a light focusing means, and a photodetector 29 as a light detecting means,
And a two-axis actuator 30 for holding and moving in the two-axis direction.

The semiconductor laser device 21 is a light-emitting device utilizing recombination light emission of a semiconductor, and emits predetermined laser light. The astigmatism correction plate 22 a is a parallel flat plate that is disposed at a predetermined angle with respect to the optical axis, and corrects the astigmatism of the light beam emitted from the semiconductor laser device 21.
The grating 22 b is a diffraction grating for diffracting incident light, and is provided from the semiconductor laser element 21 to the astigmatism correction plate 22.
The light beam incident through a is divided into at least three light beams of a main beam composed of zero-order diffracted light and side beams composed of ± first-order diffracted light. Therefore, at least 3
As long as the light beam of the book can be divided and generated, another division element such as a hologram element may be used.

The beam splitter 23 is a polarization beam splitter provided with its polarization separating film 23a inclined at 45 degrees with respect to the optical axis. The beam splitter 23 reflects the light beam from the grating 22b and the signal from the signal recording surface of the optical disk 11. The return beam is polarized and separated. That is, the semiconductor laser element 21
A part of the light beam from the light beam passes through the polarization splitting film 23a of the beam splitter 23, and a part of the return light beam is reflected by the polarization splitting film 23a of the beam splitter 23.

The collimator lens 24 is a cemented lens combining a convex lens and a concave lens, and converts the light beam from the beam splitter 23 into a parallel light beam. The prism mirror 25 is a triangular prism-shaped mirror,
The parallel light beam from the collimator lens 24 is reflected 90 degrees in the vertical direction, and the return light beam from the optical disk 11 is reflected 90 degrees in the horizontal direction. Objective lens 26
Is a convex lens constituting the light beam emitting portion 2a, which converges the parallel light beam from the collimator lens 25 and makes it incident on the incident portion 3b of the light guide means 3. Here, the objective lens 26 is driven by a two-axis actuator 30 of a shaft sliding rotation type.
It is supported so as to be movable in two axial directions, ie, a focusing direction and a tracking direction.

The Wollaston prism 27 is a quadrangular prism, and emits a plurality of light beams by performing polarization separation based on a return light beam from the optical disk 11. The multi-lens 28 is a cylindrical lens and a concave lens, and adjusts the optical path length by giving astigmatism to the return light beam for detecting a focus error signal. The photodetector 29 is a photodetector and receives the return light beam transmitted through the beam splitter 23.

The biaxial actuator 30 includes an XY base 31 mounted on the housing so as to be movable in the XY directions,
The movable unit holder 32 supports the XY base 31 so as to be movable in the optical axis direction and swingable around the swing axis so that the optical axis of the objective lens 26 is parallel to the swing axis. A lens holder 33 for holding the objective lens 26 and driving means for the objective lens 26 described later are provided.

The movable portion holder 32 is entirely made of a resin such as a rubber-like polyester elastomer. The movable portion side 32a is attached to the lens holder 33, and the fixed portion side 32b is attached to the XY base 31. Fixed against. Further, the movable portion holder 32 has a link having a substantially parallelogram vertical section so that the movable portion side 32a can move in the focusing direction. And a pair of hinges 32c and 32d extending to

The means for driving the objective lens is a lens holder 3
3 includes a focus coil 34 and a tracking coil 35, a yoke 36 fixed to the XY base 31, and a magnet 37 attached to the yoke 36. By energizing the focusing coil 34 and the tracking coil 35, the magnetic flux generated in each of the coils 34 and 35 interacts with the magnetic flux generated by the yoke 36 and the magnet 37, so that the lens holder 33 and the objective lens 26 is driven and controlled in a focusing direction and a tracking direction.

FIGS. 4A and 4B are a side view and a plan view, respectively, showing a detailed example of the light guide means 3 described above. The light guide means 3 is formed on the outer peripheral surface of the light guide part 3c made of glass or plastic having high transparency, such as an optical fiber, which can transmit a light beam, and the light guide part 3c for shielding external light. It is composed of an external light shielding film 3d. And
One end face 3a of the light guide means 3, that is, the emission part and the other end face 3b,
That is, the incident portion is formed in a hemispherical shape that acts as a lens in order to converge the light beam emitted from the light beam emitting portion 2a of the optical block 2. Light guide means 3
A magnetic field head 3e corresponding to the magnetic field modulation overwrite is provided on the one end face 3a side. This magnetic field head 3
e is made of a thin copper wire or the like and wound around the outer periphery of the external light shielding film 3d on one end surface 3a side in a coil shape, and both ends are formed along the outer periphery of the light guide means 3 as magnetic field head signal lines 3f. It is arranged on the end face 3b side.

The control unit 13 includes an optical disk drive controller 14, a signal demodulator 15, an error correction circuit 16, an interface 17, a head access control unit 18, a servo circuit 19, a signal modulator 15 ', and a magnetic field head controller 18'. ing. The optical disk drive controller 14 controls the drive of the spindle motor 12 at a predetermined rotation speed. The signal demodulator 15 demodulates the recording signal from the optical block 2 and sends it to the error correction circuit 16. The error correction circuit 16 corrects the error of the recording signal from the signal demodulator 15 and sends it to an external computer or the like via the interface 17. With this, the external computer etc.
A signal recorded on the optical disk 11 can be received as a reproduction signal.

The head access control section 18 moves the optical block 2 and rotates the light guide 3. The servo circuit 19 moves the objective lens 26 held by the biaxial actuator 30 of the optical block 2 in the focusing direction and the tracking direction. Signal modulator 1
5 ′ is an interface 17 from an external computer or the like.
Is sent to the optical block 2.
The magnetic field head controller 18 'controls the magnetic field head 3e according to a control signal input from an external computer or the like via the interface 17. Thus, the optical pickup 1 can record a signal from an external computer or the like on the optical disc 11.

The optical disk device 10 incorporating the optical pickup 1 according to this embodiment is configured as described above, and operates as follows when reproducing a signal recorded on the optical disk 11. First, the optical disk drive controller 14 drives the spindle motor 12 to rotate the optical disk 11, and
Is transmitted to the head access control unit 18. The head access control unit 18 moves the optical block 2 to reproduce the signal of the designated optical disk 11, and the light beam emitting unit 2 a of the optical block 2 faces the incident unit 3 b of the corresponding light guide unit 3. Then, the light guide means 3 is rotated, and the emission portion 3a of the light guide means 3 is moved to a designated recording track on the optical disk 11 by a track jump or the like.

In this state, the light beam from the semiconductor laser element 21 is split into three light beams by the grating 22b, and then passes through the beam splitter 23,
The light is converted into a parallel light beam by the collimator lens 24. Then, the light is reflected by the prism mirror 25 and is incident on the incident portion 3b of the light guide means 3 via the objective lens 26. The light beam incident on the incident part 3b of the light guide means 3
c, and is emitted from the emission part 3a of the light guide means 3,
It is focused on the signal recording surface of the optical disc 11.

The return light beam from the optical disk 11 is incident on the light emitting part 3a of the light guiding means 3, travels through the light guiding part 3c, and is emitted from the light incident part 3b of the light guiding means 3. Light guide means 3
The return light beam emitted from the light incident portion 3b enters the beam splitter 23 again via the objective lens 26, the prism mirror 25, and the collimator lens 24. Then, the light is reflected by the reflection surface 23a of the beam splitter 23,
The light is focused on the photodetector 29 via the Wollaston prism 27 and the multi-lens 28, and the detection signal of the photodetector 29 is sent to the signal demodulator 15.

The signal demodulator 15 includes a photo detector 29
Is demodulated and sent to the error correction circuit 16. The error correction circuit 16 corrects the error of the recording signal from the signal demodulator 15 and sends it to an external computer or the like via the interface 17 to reproduce the recording signal on the optical disk 11. At this time, the signal demodulator 15 detects a tracking error signal based on a detection signal from the photodetector 29 and detects a focusing error signal using an astigmatism method.

The servo circuit 19 servo-controls the drive current to the focusing coil 34 and the tracking coil 35 via the optical disk drive controller 14. That is, the magnetic field generated in the focusing coil 35 acts on the magnetic field generated by the magnet 37 and the coil 36, so that the lens holder 33 is moved and adjusted in the focusing direction, thereby performing focusing. Further, the magnetic field generated in the tracking coil 35 acts on the magnetic field generated by the magnet 37 and the yoke 36, so that the lens holder 33 is moved and adjusted in the tracking direction to perform tracking.

According to the above configuration, since the configuration is simple, the cost can be reduced and the failure rate can be reduced. Further, since switching of the optical disk is not required as in the conventional optical disk device, the speed of signal reproduction and recording can be increased.

The optical disk device 1 according to the above embodiment
In the optical pickup 1 and the optical pickup 1, the configurations of the polarization optical pickup and the optical disk apparatus for reproducing the magneto-optical disk are shown, but the present invention is not limited thereto, and the present invention is also applied to the non-polarization optical pickup and the optical disk apparatus. be able to. When the present invention is applied to an optical disk having a signal recording surface formed on both sides, as shown in FIG.
a are arranged so as to face each other.

[0033]

As described above, according to the present invention, downsizing can be achieved with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an optical disk device according to the present invention.

FIG. 2 is a perspective view showing an embodiment of the optical pickup of the present invention.

FIG. 3 is a side view and a plan view showing a detailed example of an optical block of the optical pickup of FIG. 2;

FIG. 4 is a side view and a plan view showing a detailed example of a light guide unit of the optical pickup of FIG. 2;

FIG. 5 is a perspective view showing another embodiment of the optical pickup of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical pickup, 2 ... Optical block, 2
a: light beam emitting part, 3, 43: light guide means, 3
a, 43a ... outgoing part, 3b ... incoming part, 3c ...
-Light guide part, 3d-external light shielding film, 3e-magnetic field head, 3f-magnetic field head signal line, 10-optical disk device, 11, 41-optical disk, 12-spindle Motor, 13: control unit, 14: optical disk drive controller, 15: signal demodulator, 1
6 ... Error correction circuit, 17 ... Interface,
18 head access control section, 19 servo circuit, 20 optical system, 21 semiconductor laser element,
22a: astigmatism correction plate, 22b: grating, 23: beam splitter, 24: collimator lens, 25: prism mirror, 26: objective lens, 27: Wollaston Prism, 28 ...
・ Multi-lens, 29 ・ ・ ・ Photo detector, 30 ・
..Two-axis actuator, 31 ... XY base, 32
... Movable part holder, 33 ... Lens holder, 34
..Focusing coils, 35 ... Tracking coils, 36 ... Yoke, 37 ... Magnets

Claims (4)

[Claims] 1. An optical pickup for reproducing and / or recording signals on at least two consecutively mounted optical disks having a signal recording surface formed on one surface or at least one optical disk having a signal recording surface formed on both surfaces. An optical block that emits a light beam; and at least two light beams emitted from the optical block are incident from an incident portion to guide the light beam, and are emitted from each of the signal recording surfaces of the optical disk from the emission portion to be focused. The optical block is configured to be movable between the entrances of the respective light guides, and the respective light guides are arranged such that the exits have the entrances as a rotation axis. An optical pickup characterized by being rotatable along a signal recording surface of each optical disc. 2. The optical pickup according to claim 1, wherein said light guide means includes a rod-shaped light guide portion made of a material having high transparency. 3. The optical pickup according to claim 1, wherein an entrance and an exit of the light guide are formed in a hemispherical shape. 4. An optical pickup for reproducing and / or recording signals on at least two consecutively mounted optical disks having a signal recording surface formed on one surface or at least one optical disk having a signal recording surface formed on both surfaces. An optical disc device comprising: the optical pickup; an optical block that emits a light beam; and a light beam emitted from the optical block is incident from an incident portion to guide the light beam, and is emitted to each signal recording surface of the optical disc. And at least two light guide means for emitting light from the part and converging the light, wherein the optical block is configured to be movable between incident parts of the respective light guide means, and each of the light guide means is configured to be the incident part. An optical disk device, wherein the light-emitting unit is configured to be rotatable along a signal recording surface of each of the optical disks, with a rotation axis as a rotation axis.