JPH11185267A - Optical pickup and optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate dealing with optional two kinds of disks, for example, among plural kinds of optical disks having different wavelengths. SOLUTION: An optical pickup 20 is provided with a light converging means for projecting a light beam emitted from a light source to be focussed on the signal recording surface of an optical disk, biaxial actuators 31b to 32b for driving and adjusting the light converging means in a biaxial direction, and a photodetector for receiving the light beam returning from the signal recording surface of the optical disk. The light converging means and the biaxial actuators 31b to 32b are unitized as a biaxial block, the light source and an optical system including the photodetector are unitized as an optical unit, two groups of biaxial units (biaxial blocks) 30 and an optical unit (optical block) 40 are attached to a reference base 21 so as to be detached, and according to the kind of an optical disk to be recorded/reproduced, the two groups of biaxial block 30s and the optical block 40 are switched to be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical recording medium,
For example, an optical pickup and an optical disk device for recording and reproducing information on a compact disk (CD), a CD-ROM, a magneto-optical disk, etc. (hereinafter, referred to as an "optical disk"), and particularly capable of reproducing a plurality of types of optical disks having different disk formats And an optical disk device.

[0002]

2. Description of the Related Art Conventionally, optical disks include, for example, CDs and Cs.
Since there are a plurality of types of formats such as D-R, MD, MO, and high-density recording optical disks, a dedicated optical pickup is required for recording or reproducing a specific optical disk. Each type of optical pickup requires a manufacturing facility. Therefore, there is a problem that the manufacturing cost is increased.

[0003] For this reason, an optical pickup for reproducing a plurality of types of optical disks has been disclosed. For example, a plurality of types of optical disks, for example, a compact disk (C
D) and an optical pickup for reproducing high-density optical discs, for example, 650 nm and 780 nm in order to cope with reproduction of CD-R in all wavelength regions.
There is a need for a two-wavelength optical pickup provided with light sources in two wavelength ranges. Such a two-wavelength optical pickup is configured, for example, as shown in FIG.

In FIG. 7, an optical pickup 1 is actually composed of two sets of optical pickups. In the case shown in the figure, a first optical pickup 2 for reproducing a first type of optical disc D1 such as a CD. Is composed of, for example, a light emitting / receiving element 3, a rising mirror 2a, and an objective lens 2b. A second optical pickup 4 for reproducing a second type optical disc D2 such as a high density optical disc is a semiconductor laser element. 4a, a grating 4b, a beam splitter 4c, a collimator lens 4d, a rising mirror 4e, an objective lens 4f, a multi-lens 4g, and a photodetector 5.

First, with respect to the first optical pickup 2, the objective lens 2b is a convex lens, and the light beam from the light emitting / receiving element 3 is focused on a desired track on the signal recording surface of the optical disk D1 which is driven to rotate. Make an image. further,
The objective lens 2b is supported by a biaxial actuator (not shown) so as to be movable in a biaxial direction, that is, a focusing direction and a tracking direction. The light emitting and receiving element 3 has a known configuration for a CD, and is formed by enclosing a light emitting element and a light receiving element in a semiconductor package as an integrated optical block.

According to the first optical pickup 1 having such a configuration, the light beam emitted from the light emitting element of the light receiving / emitting element 3 is transmitted to the first type optical disk via the rising mirror 2a and the objective lens 2b. An image is formed at a certain point on the signal recording surface of D1. The return light beam reflected on the signal recording surface of the optical disk D1 again enters the light receiving element of the light emitting / receiving element 3 via the objective lens 2b and the rising mirror 2a. Thus, based on the detection signal output from the light receiving element of the light receiving / emitting element 3, the information recorded on the signal recording surface of the optical disc D1 is reproduced, and the focus error signal and the tracking error signal are detected.

On the other hand, the second optical pickup 4
The grating 4b is a diffraction grating, and converts the light beam incident from the semiconductor laser element 4a to 0.
The beam is split into a main beam as a secondary light and a side beam as a plus or minus primary light. The beam splitter 4c is disposed with its reflection surface inclined at 45 degrees with respect to the optical axis, and separates the light beam emitted from the semiconductor laser element 4a from the return light from the signal recording surface of the optical disc D2. That is, the light beam from the semiconductor laser element 4a is reflected by the reflection surface of the beam splitter 4c, and the return light from the optical disk D2 passes through the beam splitter 4c.

The objective lens 4f is a convex lens, reflected by the beam splitter 4c, and
The light beam converted into parallel light at d is imaged on a desired track on the signal recording surface of the optical disk D2 that is driven to rotate. Further, the objective lens 4f is supported by a biaxial actuator (not shown) so as to be movable in a biaxial direction, that is, a focusing direction and a tracking direction. The photodetector 5 is configured to have a light receiving unit for each of the return light beams transmitted through the beam splitter 4c and incident via the multi-lens 4g.

According to the optical pickup 4 having such a configuration, the light beam emitted from the semiconductor laser element 4a is
After being split into a main beam and two side beams by the grating 4b, the beam is reflected by the reflection surface of the beam splitter 4c, converted into parallel light by the collimator lens 4d, and then passed through the rising mirror 4e and the objective lens 4f. An image is formed at a certain point on the signal recording surface of the second type optical disc D2. The return light beam reflected on the signal recording surface of the optical disk D2 again enters the beam splitter 4c via the objective lens 4f and the rising mirror 4e. Here, the return light beam passes through the beam splitter 4c and enters the light receiving unit of the photodetector 5 via the multi-lens 4g. Thereby, based on the detection signal output from each light receiving unit of the photodetector 5, information recorded on the signal recording surface of the optical disc D2 is reproduced, and
A focus error signal and a tracking error signal are detected.

[0010]

However, the dual-wavelength optical pickup 1 having such a structure is designed to use a dedicated optical pickup 2 for each type of optical disc.
By incorporating 4, the optical system including the light source, the objective lens, and the biaxial actuator for driving the objective lens in the biaxial directions are provided in duplicate. Therefore, there is a problem that the number of parts increases and the overall size and weight increase.

Further, in the above-described optical pickup 1, each of the dedicated optical pickups 2 and 4 is designed to correspond to the formats of the first and second types of optical discs, respectively, and has a different format. It is impossible to support optical disks. Therefore, in order to perform recording or reproduction of an optical disk of another different format, it is necessary to newly redesign the optical pickup 1 as a whole, and there is a problem that the design cost and the production cost increase.

In view of the above, the present invention provides an optical pickup and an optical disk apparatus which can easily cope with any two types of optical disks among a plurality of types of optical disks having different wavelengths. The purpose is.

[0013]

According to the present invention, a light source for emitting a light beam and a light beam emitted from the light source are focused on a signal recording surface of a rotationally driven optical disk. A light focusing means for irradiating, and a biaxial actuator for driving and adjusting the light focusing means in two axial directions,
An optical pickup including a photodetector for receiving a return light beam from a signal recording surface of the optical disc, wherein the light focusing means and the biaxial actuator are standardized as a biaxial block according to the type of the optical disc. The optical system including the light source and the photodetector is standardized and unitized as an optical block according to the type of the optical disc, and the optical system including different types of the biaxial block and the optical block. The set is mounted on a reference base, and according to the type of the optical disc to be recorded or reproduced, the two sets of the biaxial block and the optical block are configured to be used by switching, by an optical pickup, Achieved.

According to the above configuration, the components of the optical pickup are unitized as a biaxial block and an optical block, and the two sets of biaxial blocks and the optical block are detachably attached to the reference base of the optical pickup. In addition, a plurality of biaxial blocks and optical blocks designed to correspond to a plurality of types of optical discs are prepared.

Therefore, in order to reproduce a first type of optical disk such as a high-density optical disk and a second type of optical disk such as a CD-ROM and a CD-R, the first type of optical disk and the second Two sets of biaxial blocks and optical blocks designed for various types of optical disks are mounted on a reference base of an optical pickup.

Thus, in the case of recording or reproduction of the first type of optical disk, the optical disk is switched to the first biaxial block and the first optical block, and the light beam from the light source of the first optical block is changed. An image is formed on the signal recording surface of the first type optical disk via the light focusing means of the first biaxial block. Then, the return light from the signal recording surface of the first type optical disk again enters the photodetector of the first optical block via the light focusing means of the first biaxial block. Thus, recording or reproduction of the first type of optical disk is performed.

In the case of recording or reproducing data of the second type of optical disk, the optical disk is switched to the second biaxial block and the second optical block, and the light beam from the light source of the second optical block is An image is formed on the signal recording surface of the second type of optical disk via the light focusing means of the second biaxial block. Then, the return light from the signal recording surface of the second type of optical disk again enters the photodetector of the second optical block via the light focusing means of the second biaxial block. Thus, recording or reproduction of the second type of optical disk is performed.

Similarly, in the case of recording or reproduction of another type of optical disk, the third biaxial block and the third optical block designed corresponding to the type of optical disk are used for the above-mentioned first type of optical disk. Alternatively, it is attached to the reference base of the optical pickup instead of the second biaxial block and the first or second optical block. Thus, the light beam from the light source of the third optical block is imaged on the signal recording surface of the optical disk of the type via the light focusing means of the third biaxial block. Then, the return light from the signal recording surface of this type of optical disk again enters the photodetector of the third optical block via the light focusing means of the third biaxial block. Thus, recording or reproduction of the optical disk of that type is performed.

In this manner, of a plurality of sets of biaxial blocks and optical blocks designed for a plurality of types of optical discs prepared in advance, one corresponding to the type of the optical disc to be recorded or reproduced. A pair of biaxial blocks and an optical block are attached to a reference base of an optical pickup, so that an optical pickup corresponding to two types of optical disks to be recorded or reproduced is constituted. Will be recorded or reproduced correctly.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. still,
Since the embodiments described below are preferred specific examples of the present invention, various technically preferred limitations are added.
The scope of the present invention is not limited to these embodiments unless otherwise specified in the following description.

FIG. 1 shows the configuration of an optical disk device incorporating one embodiment of the optical pickup according to the present invention. In FIG. 1, an optical disk device 10 is an optical disk device for reproducing an optical disk, and has a spindle motor 12 as a driving unit for driving the optical disk 11 to rotate.
And an optical pickup 20 for irradiating a signal recording surface of the rotating optical disk 11 with a light beam to record a signal, reproducing a recorded signal by a return light beam from the signal recording surface, and a control unit 13 for controlling these. The optical disc 11 selects a plurality of types of optical discs,
Each can be played. Here, the control unit 13 includes the optical disk controller 14 and the signal demodulator 1
5, an error correction circuit 16, an interface 17, a head access control unit 18, and a servo circuit 19.

The optical disk 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 pickup 20, corrects the error, and sends the signal to an external computer or the like via the interface 17. Thus, an external computer or the like can receive a signal recorded on the optical disk 11 as a reproduction signal.

The head access control section 18 moves the optical pickup 20 to a predetermined recording track on the optical disk 11, for example, by a track jump or the like. The servo circuit 19 moves the objective lens held by the biaxial actuator of the optical pickup 20 in the focusing direction and the tracking direction at the moved predetermined position.

FIG. 2 shows a preferred embodiment of an optical pickup incorporated in the optical disk device 10. In FIG. 2, an optical pickup 20 includes a reference base 21 and two sets of a two-axis unit 30 and an optical unit 4 that are detachably attached to the reference base 21.
0.

The biaxial unit 30 comprises an objective lens as a light focusing means and a biaxial actuator for driving the objective lens in biaxial directions among the optical elements constituting the optical pickup 20. Have been. As shown in FIG. 3, the biaxial unit 30 includes a plurality (three in the illustrated case) of biaxial blocks 31, 32, and 33 designed for a plurality of types of optical disks. I have. Here, the first two-axis block 31 corresponding to the first type of optical disk includes, as an objective lens 31a and a two-axis actuator 31b, for example, an objective lens 21b in the optical pickup 2 shown in FIG. (Not shown).

A second biaxial block 32 corresponding to a second type of optical disk includes, as an objective lens 31a and a biaxial actuator 31b, for example, an objective lens 4f in the optical pickup 4 shown in FIG. A shaft actuator (not shown) is included. Further, the third biaxial block 33 includes an objective lens and a biaxial actuator designed corresponding to a third type of optical disc. Each of the biaxial blocks 31, 32, and 33 has a standardized mounting portion (not shown) to the reference base 21. On the other hand, they are arranged at predetermined optical positions.

The optical unit 40 comprises optical elements including a light source and a photodetector among the optical elements constituting the optical pickup 20. As shown in FIG. 3, the optical unit 40 is provided with a plurality (three in the illustrated case) of optical blocks 41, 42, 43 designed for a plurality of types of optical disks. Here, the first optical block 41 corresponding to the first type of optical disk is, for example, the optical pickup 2 shown in FIG.
The light emitting / receiving element 3 and the rising mirror 2a in FIG.

The second optical block 42 corresponding to the second type of optical disk includes, for example, the semiconductor laser element 4a, the grating 4b, the beam splitter 4c, the collimator lens 4d, and the vertical lens in the optical pickup 4 shown in FIG. It includes a raising mirror 4e, a multi-lens 4g, and a photodetector 5. Further, the third optical block 43
Is designed for a third type of optical disc. Each optical block 41, 42, 43 has a standardized mounting portion (not shown) to the reference base 21. Each is arranged at a predetermined optical position.

The biaxial base 30 and the optical base 4
0 indicates that two sets of two-axis bases and optical bases respectively corresponding to arbitrary two types of optical disks are selected, attached to the reference base 21, and appropriately switched and used according to the optical disk to be recorded or reproduced. It is supposed to be.

The optical pickup 20 according to the present embodiment
Are configured as described above. First, an optical disk D1 of a first type (for example, a high-density recording optical disk) and an optical disk of a second type (for example, a CD-ROM or a CD-ROM)
R), as shown in FIG. 4, the optical pickup 20 includes two sets of biaxial blocks 3 corresponding to the first type optical disc D1 and the second type optical disc D2.
1 and 32 and the optical blocks 41 and 42 are
Attach to 1.

When reproducing the first type of optical disk D1, the optical pickup 20 uses the first two-axis block 31 and the first optical block 41 for switching, and the spindle motor 12 of the optical disk device 10 By rotating, the optical disc D1 is rotationally driven.
Then, by moving the optical pickup 20 in the radial direction of the optical disc D1 along the guide, the optical axis of the objective lens 31a is moved to a desired track position of the optical disc D1 to perform access.

As a result, in the optical pickup 20,
A light beam from a light source in the optical block 41 is emitted toward the optical disc D1, and is irradiated on the signal recording surface of the optical disc D1 via the objective lens of the biaxial block 31.

The return light from the optical disk D1 again enters the optical block 41 via the objective lens, and then enters the light detecting section of the light emitting / receiving element. Thereby, the recording signal of the optical disk D1 is reproduced based on the detection signal of the photodetector. At this time, a tracking error signal and a focus error signal are detected by the signal demodulator 15 based on the detection signal from the photodetector, and the servo circuit 19 is output via the optical disk drive controller 14.
Drives and controls the biaxial actuator to perform focusing and tracking.

Next, when reproducing the second type of optical disk D2, the optical pickup 20 uses the second biaxial block 32 and the second optical block 42 in a switched manner, and in the same manner, the optical disk D2 Is reproduced, and focusing and tracking are performed by the biaxial actuator of the second biaxial block 32.

In the case of supporting the second type optical disk D2 and the third type optical disk, as shown in FIG. 5, the optical pickup 20 includes the second type optical disk D2 and the third type optical disk. Two sets of biaxial blocks 32 and 33 and optical blocks 42 and 43 corresponding to D3
Is attached to the reference base 21. Then, when reproducing the second type of optical disk D2, the optical pickup 20 uses the second biaxial block 32 and the second optical block 42 for switching and performs reproduction of the optical disk D2. Focusing and tracking are performed by the biaxial actuator of the biaxial block 32.

Next, when reproducing the optical disk D3 of the third type, the optical pickup 20 uses the third biaxial block 33 and the third optical block 43 for switching, and in the same manner, the optical disk D3 Is reproduced, and focusing and tracking are performed by the biaxial actuator of the third biaxial block 33.

Further, when the optical pickup 20 corresponds to the first type optical disk D1 and the third type optical disk, as shown in FIG. 6, the optical pickup 20 includes the first type optical disk D1 and the third type optical disk. Two sets of biaxial blocks 31, 33 and optical blocks 41, 43 corresponding to D3
Is attached to the reference base 21. When the first type of optical disc D1 is reproduced, the optical pickup 20 uses the first biaxial block 31 and the first optical block 41 for switching, and performs the reproduction of the optical disc D1. Focusing and tracking are performed by the biaxial actuator of the biaxial block 31. Next, when playing back the third type of optical disc D3, the optical pickup 20 uses the third biaxial block 33 and the third optical block 43 for switching, and in the same manner, plays back the optical disc D3. At the same time, focusing and tracking are performed by the biaxial actuator of the third biaxial block 33.

As described above, according to the optical pickup 20 of the present embodiment, any two types of the two-axis unit 30 and the optical unit 40 designed corresponding to a plurality of types of optical disks are used. Two sets of two-axis unit 30 and optical unit 40 corresponding to optical disc
Is detachably attached to the reference base 21 and includes a light source and an objective lens that are optimal for the type of optical disc by switching and using a biaxial block and an optical block corresponding to the type of optical disc to be reproduced. An optical system will be used, and the reproduction of the optical disc will be performed accurately, and the reproduction of two types of optical discs will be easily performed by switching between two sets of biaxial blocks and optical blocks. . Thus, with respect to optical pickups for different types of optical discs,
As a result, the cost of parts can be reduced, the production equipment can be shared, the development time can be shortened, and the production cost can be reduced.

In the above embodiment, three biaxial blocks 31, 32, and 33 are provided for three types of optical discs.
And three optical blocks 41, 42, and 43 are prepared, but four or more biaxial blocks and optical blocks designed corresponding to four or more types of optical discs are prepared. Obviously, two sets of biaxial blocks and optical blocks corresponding to the optical disk of the above may be selectively attached to the reference base. In this case, the objective lens of the biaxial block is designed corresponding to different types of optical discs, and
The light sources of the optical blocks are configured to emit light beams suitable for recording or reproduction of different types of optical discs.

In the above-described embodiment, the optical disk apparatus for reproducing the optical disk has been described. However, the present invention is not limited to this, and the optical disk apparatus for recording and reproducing an optical disk such as a writable optical disk and a magneto-optical disk, and It is clear that the present invention can be applied to an optical pickup.

[0041]

As described above, according to the present invention, it is possible to provide an optical pickup and an optical disk apparatus which can easily cope with any two types of optical disks among a plurality of types of optical disks having different wavelengths. it can.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an optical disc device incorporating an embodiment of an optical pickup according to the present invention.

FIG. 2 is a schematic side view showing a configuration of an embodiment of an optical pickup in the optical disk device of FIG. 1;

FIG. 3 is a schematic view showing a biaxial block and an optical block to be attached to the optical pickup of FIG. 2;

FIG. 4 is a schematic side view showing a combination for reproducing first and second types of optical disks in the optical pickup of FIG. 2;

FIG. 5 is a schematic side view showing a combination for reproducing second and third types of optical discs in the optical pickup of FIG. 2;

FIG. 6 is a schematic side view showing a combination for reproducing first and third types of optical discs in the optical pickup of FIG. 2;

FIG. 7 is a schematic view showing an example of a conventional optical pickup.

[Explanation of symbols]

10 optical disk device, 11 optical disk, 1
2 ... Spindle motor, 13 ... Control unit, 14.
..Optical disk drive controller, 15 ... signal demodulator, 16 ... error correction circuit, 17 ... interface, 18 ... head access control unit, 20 ...
・ Optical pickup, 21 ・ ・ ・ Reference base, 30, 3
1, 32, 33 ... two-axis block, 31a, 32a
..Objective lenses, 31b, 32b... Biaxial actuators, 40, 41, 42, 43.

Claims (4)

[Claims] A light source for emitting a light beam; a light converging means for irradiating the light beam emitted from the light source so as to be focused on a signal recording surface of a rotationally driven optical disc; and a light converging means. A biaxial actuator for driving and adjusting in a biaxial direction; and a photodetector for receiving a return light beam from the signal recording surface of the optical disc, wherein the light focusing means and the biaxial actuator are adapted to the type of the optical disc. The optical system including the light source and the photodetector is standardized and unitized as an optical block according to the type of the optical disc. Two sets of different types of optical blocks are mounted on the reference base, and the above two sets are set according to the type of optical disc to be recorded or reproduced. The optical pickup, wherein the axial block and optical block is configured to be used by switching. 2. The two-axis block and the optical block,
2. The optical pickup according to claim 1, wherein the optical pickup is designed for a specific type of optical disk. 3. A plurality of sets of biaxial blocks and optical blocks designed respectively corresponding to a plurality of types of optical discs are provided, and two sets of biaxial blocks and optical blocks corresponding to any two kinds of optical discs are provided. The optical pickup according to claim 2, wherein is selected and attached to a reference base. 4. A driving means for driving the optical disc to rotate, and a light source irradiating the rotating optical disc with light from a light source through a light focusing means, and returning light from a signal recording surface from the optical disc through the light focusing means. An optical pickup that detects with a photodetector, a biaxial actuator that supports the objective lens movably in biaxial directions, a signal processing circuit that generates a reproduction signal based on a detection signal from the photodetector, A servo circuit for moving the light focusing means in two axial directions based on a detection signal from the optical disk, wherein the light focusing means and the two-axis actuator are adapted to the type of the optical disk. The optical system including the light source and the photodetector is standardized as an optical block according to the type of the optical disc. The two sets of different types of the biaxial block and the optical block are mounted on a reference base, and the two sets of the two sets are set according to the type of the optical disc to be recorded or reproduced. An optical disc device, wherein a shaft block and an optical block are switched and used.