JP2001056950A - Optical pickup and optical disk drive - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To increase the degree of freedom of component arrangement. SOLUTION: In a state where a semiconductor laser element 21 and a photodetector 22 for receiving reflected return light from an optical disk 5 are arranged in parallel and in parallel with the disk surface 5a, the same package 24 is provided.
And the integrated optical optics in which the emission optical axis position 25 of the laser light emitted from the semiconductor laser element is shifted to one side 24a of the package in the parallel direction of the semiconductor laser element and the photodetector. An optical pickup 7 including an element 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel optical pickup and an optical disk drive. More specifically, the present invention relates to a technique for increasing the degree of freedom of component arrangement in an optical pickup.

[0002]

2. Description of the Related Art Conventionally, an emission optical axis c of an integrated optical element b in which a semiconductor laser element and a photodetector for receiving reflected return light from an optical disk are arranged in the same package a is shown in FIG. In addition, it was located at a ratio of 1: 1 to the width W of the package a.

[0003]

However, when the above-mentioned conventional integrated optical element b is used, there is a problem that the arrangement of each component of the optical pickup is restricted.

For example, when the optical axis of the objective lens is perpendicular to the emission optical axis of the integrated optical element, the number of components can be reduced, but the integrated optical element is wider than the width of the two-axis actuator having the objective lens. Since the width of b is greater, the integrated optical element b needs to be equidistant in the width direction around the objective lens, which hinders miniaturization of the optical disk drive. That is,
Since the optical pickup moves in the radial direction of the optical disk rotated by the spindle motor, the size of the outside of the optical pickup around the optical axis of the objective lens, that is, the side opposite to the side where the spindle motor is located, is reduced. By doing so, the position outside the optical pickup when the optical pickup moves to the outermost periphery of the optical disk becomes closer to the center, and the optical disk drive device can be downsized accordingly.

In order to prevent the position outside the integrated optical element b from protruding outside the outside of the biaxial actuator having the objective lens d, as shown in FIG.
A mirror f for bending the optical path is required in addition to the rising mirror e on the optical path from the integrated optical element b to the objective lens d, which increases the number of parts and increases the cost.

Therefore, an object of the present invention is to increase the degree of freedom in arranging components.

[0007]

In order to solve the above-mentioned problems, an optical pickup according to the present invention comprises a semiconductor laser element and a photodetector for receiving reflected return light from an optical disk are arranged in parallel and parallel to the disk surface. The laser beam emitted from the semiconductor laser device is disposed in the same package in a state where the laser beam is emitted from the semiconductor laser device, and the optical axis position of the laser beam is shifted to one side of the package in the parallel direction of the semiconductor laser device and the photodetector. An integrated optical element is provided.

Therefore, according to the optical pickup of the present invention,
By setting the position of the output optical axis as desired,
The degree of freedom in component arrangement can be increased.

Further, the optical disk drive of the present invention comprises:
It has a spindle motor for rotating the optical disk, an optical pickup for irradiating the optical disk with light and detecting the reflected light, and a thread mechanism for moving the optical pickup in the radial direction of the optical disk. And a photodetector for receiving the reflected return light are arranged in the same package in parallel with and parallel to the disk surface, and the position of the emission optical axis of the laser light emitted from the semiconductor laser element is changed. And an integrated optical element at a position deviated to a side of the package in a direction parallel to the photodetector opposite to a side where the spindle motor is located.

Therefore, in the optical disk drive of the present invention, the amount of projection from the optical axis of the objective lens to the outside of the optical pickup, that is, the outermost peripheral side of the optical disk rotated by the spindle motor can be reduced. Thereby, miniaturization becomes possible.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the optical pickup and optical disk drive of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 schematically shows an optical disk drive 1.

A spindle motor 3 is disposed substantially at the center of the chassis 2, and an optical disk 5 is mounted on a turntable 4 rotated by the spindle motor 3 and rotated.

A large opening 6 is formed in the chassis 2 from the center where the spindle motor 3 is disposed to one side, and the optical pickup 7 is turned on the turntable 4 with most of the optical pickup 7 positioned in the opening 6. It moves in the radial direction of the optical disc 5 placed thereon.

The optical pickup 7 has necessary components mounted on a slide base 8. That is, an integrated optical element 9 in which a semiconductor laser element, a photodetector, and required optical elements are arranged in one package, and a laser beam emitted from the integrated optical element 9 is applied to a signal recording surface of the optical disk 5. A two-axis actuator 11 having an objective lens 10 for receiving the reflected return light and returning it to the integrated optical element 9, a rising mirror 12 for guiding the laser light emitted from the integrated optical element 9 to the objective lens 10, and the like are a slide base 8. It is installed in.

One end of the slide base 8 is slidably fitted on the guide shaft 13, and the other end of the slide base 8 is a piece to be guided 14, 1, which projects vertically and in parallel.
At 4 (only one is shown), another guide shaft 15 is slidably clamped, whereby the slide base 8 is movable in the radial direction of the optical disk 5.

The sled mechanism 16 is connected to the motor 1 via a motor 17 supported by the chassis 2 and a gear transmission mechanism 18.
A pinion 19 is rotated by the pinion 7 and a rack 20 is fed by the pinion. The rack 20 is connected to one end of the slide base 8.

Therefore, when the motor 17 rotates, the rack 20 is sent by the pinion 19 rotated by the motor 17, and the slide base 8 is moved to the guide shafts 13 and 15 in the radial direction of the optical disk 5 placed on the turntable 4. Guided and moved.

As shown in FIG. 4, the integrated optical element 9 is formed by integrating a semiconductor laser element 21 and a photodetector 22 on a lead frame 23 in a state where the semiconductor laser element 21 and the photodetector 22 are parallel and parallel to the disk surface 5a of the optical disk 5. It is provided in one resin package 24 together with the optical element. Then, the emission optical axis 25 of the laser light of the integrated optical element 9 is located at a position offset to one side. That is, the emission optical axis 25 is located at a position of 2.2 mm from the outer peripheral side surface 24a of the package 24. By using such an integrated optical element 9, it is possible to reduce the amount of protrusion of the optical pickup 7 from the optical axis of the objective lens 10 to the outer peripheral side, that is, the side opposite to the side where the spindle motor 3 is located. Therefore, when the optical pickup 7 reads the signal on the outermost periphery of the recording area of the optical disk 5, the spindle motor 3 at the position of the outer peripheral end 7a of the optical pickup 7
The distance L from the optical disk drive becomes small, and as a result, the optical disk drive 1 itself can be downsized.

In the optical disk drive 1 described above, when reading a signal from the optical disk 5, the spindle motor 3 is driven while the optical disk 5 is mounted on the turntable 4 to rotate the optical disk 5. Then, while moving the optical pickup 7 in the radial direction of the optical disk 5, the laser beam emitted from the semiconductor laser element 21 of the integrated optical element 9 is spotted on the signal recording surface of the optical disk 5 by the objective lens 10 via the rising mirror 12. Irradiate. The return light of the spot-irradiated laser light reflected from the signal recording surface of the optical disk 5 is transmitted through the objective lens 10 and the rising mirror 12 to the integrated optical element 9.
Incident on Then, the return light incident on the integrated optical element 9 is detected by the photodetector 22, and a predetermined process is performed. That is, the tracking error signal and the focus error signal detected from the return light are sent to the servo system and become signals on which the tracking servo and the focusing servo are applied. The data signal is sent to the data processing unit.

In the above-described optical pickup, since the position of the emission optical axis of the laser light in the integrated optical element is displaced to one side in the parallel direction of the semiconductor laser element and the photodetector, it is positioned at the center. By setting the position of the emission optical axis as desired as compared with the case where the light is emitted from, it is possible to increase the degree of freedom in component arrangement.

In the case where the position of the output optical axis is deviated to the side opposite to the side where the spindle motor for rotating the optical disk is located, the protrusion of the optical pickup toward the outer peripheral side of the optical disk is reduced. Accordingly, the size of the optical disk drive can be reduced accordingly.

It should be noted that the shapes and structures of the respective parts shown in the above-described embodiments are merely examples of the embodiments to be carried out when carrying out the present invention, and the technical scope of the present invention will be described below. Should not be interpreted restrictively.

[0024]

As is apparent from the above description, the optical pickup of the present invention has a state in which the semiconductor laser element and the photodetector for receiving the reflected return light from the optical disk are parallel and parallel to the disk surface. And the laser beam emitted from the semiconductor laser device is located in the same package, and the optical axis position of the laser beam is shifted to one side of the package in the parallel direction of the semiconductor laser device and the photodetector. An optical element is provided.

Therefore, according to the optical pickup of the present invention,
By setting the position of the output optical axis as desired,
The degree of freedom in component arrangement can be increased.

According to the second aspect of the present invention, the position of the output optical axis of the integrated optical element is deviated to the side opposite to the side on which the spindle motor for rotating the optical disk is located. Projection to the outer peripheral side can be reduced.

According to the third aspect of the present invention, the optical axis of the objective lens which irradiates the laser beam onto the optical disk and receives the return light reflected by the optical disk is orthogonal to the emission optical axis of the integrated optical element. Since the optical path changing optical component between the objective lens and the integrated optical element is made up of only one mirror, the number of components can be reduced.

Further, the optical disk drive of the present invention comprises:
An optical disk drive device for recording and / or reproducing information on an optical disk, comprising: a spindle motor for rotating the optical disk; an optical pickup for irradiating the optical disk with light and detecting a reflected light thereof; The optical pickup includes a sled mechanism for moving in a radial direction, and the optical pickup is arranged in the same package in a state where a semiconductor laser element and a photodetector for receiving reflected return light from an optical disk are arranged in parallel with and parallel to the disk surface. In addition, the emission optical axis position of the laser light emitted from the semiconductor laser element is located at a position deviated to the side opposite to the side where the spindle motor is located of the package in the parallel direction of the semiconductor laser element and the photodetector. It is characterized by having an integrated optical element.

Therefore, in the optical disk drive of the present invention, the amount of projection from the optical axis of the objective lens to the outside of the optical pickup, that is, the outermost peripheral side of the optical disk rotated by the spindle motor can be reduced. Accordingly, the position of the optical pickup when the optical pickup moves to the outermost periphery of the optical disk can be set further inside, and the size of the optical disk drive can be reduced.

[Brief description of the drawings]

FIG. 1 shows an embodiment of an optical pickup and an optical disk drive of the present invention together with FIGS. 2 to 4, and FIG. 1 is a plan view schematically showing an optical disk drive.

FIG. 2 is a plan view schematically showing an optical pickup.

FIG. 3 is a perspective view showing an optical path diagram of main components.

4 is an enlarged cross-sectional view of the integrated optical element taken along a line IV-IV in FIG.

FIG. 5 is a schematic perspective view showing an example of a conventional optical pickup.

[Explanation of symbols]

1: optical disk drive device, 3: spindle motor,
DESCRIPTION OF SYMBOLS 5 ... Optical disk, 5a ... Disk surface, 7 ... Optical pickup, 9 ... Integrated optical element, 10 ... Objective lens, 11 ... Biaxial actuator, 12 ... Start-up mirror, 16 ... Thread mechanism, 21 ... Semiconductor laser element, 22 ... Photodetector, 2
4 ... Package, 24a ... One side, 25 ... Outgoing optical axis

Continued on the front page (72) Inventor Noriaki Nishi 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo F-term in Sony Corporation (reference) 5D119 AA03 AA39 BA01 CA09 EC38 FA05 FA24 FA35 LB04 LB06

Claims (4)

[Claims] 1. A semiconductor laser device and a photodetector for receiving reflected return light from an optical disk are arranged in the same package in a state of being parallel to and parallel to the disk surface and emitted from the semiconductor laser device. An optical pickup comprising: an integrated optical element in which an emission optical axis position of a laser beam is shifted to one side of the package in a direction parallel to the semiconductor laser element and the photodetector. 2. The optical pickup according to claim 1, wherein the position of the output optical axis of the integrated optical element is deviated to the side opposite to the side on which the spindle motor for rotating the optical disk is located. 3. An optical axis of an objective lens which irradiates the laser beam onto the optical disk and receives return light reflected by the optical disk, and an output optical axis of the integrated optical element is orthogonal to the objective lens and the integrated optical element. 2. The optical pickup according to claim 1, wherein the optical component for changing the optical path between the optical pickup and the optical pickup is only one rising mirror. 4. An optical disk drive device for recording and / or reproducing information on and from an optical disk, comprising: a spindle motor for rotating the optical disk; an optical pickup for irradiating the optical disk with light and detecting reflected light thereof; A thread mechanism for moving the optical pickup in a radial direction of the optical disk; the optical pickup includes a semiconductor laser element and a photodetector for receiving reflected return light from the optical disk in the same package in a state of being parallel to and parallel to the disk surface; The position of the optical axis of the laser light emitted from the semiconductor laser element is arranged on the side opposite to the side where the spindle motor is located of the package in the parallel direction of the semiconductor laser element and the photodetector. Light having an integrated optical element at a deviated position Disk drive device.