JPH11273130A - Optical pickup device and optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical pickup device easily fitting a reflection mirror to an optical base even when it is thinned. SOLUTION: This optical pickup device is provided with a holder main body 51 fitted to an optical base 10 fitted with a first light source emitting a laser beam irradiating an optical disk and formed with a hole part 51a passing the laser beam through and a support member 52 whose base end side is fitted to this holder main body 51 and whose tip side is fitted to a reflection mirror 15 for changing the direction of the laser beam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup device and an optical disk device which support an optical component for changing the direction of a laser beam emitted from a light source and record and reproduce signals on and from an optical disk. On what is possible.

[0002]

2. Description of the Related Art An optical pickup device is used in a system for recording and reproducing information using an optical disk as a recording medium, such as an optical disk device. The optical pickup device records information by irradiating the optical disk with laser light, and receives information reflected from the optical disk to read information. The optical pickup device includes an optical system, a focusing control unit, and a tracking control unit for accurately irradiating a recording track of an optical disc with a laser beam.

In recent years, the types of optical disks have been
Various discs have been developed. Recently, a digital video disk (DVD) has been developed as an optical disk. This digital video disk (DVD) has the same diameter of 12 cm as a conventional compact disk (CD), but has a different track interval due to a difference in recording density. That is, the track interval of the DVD is 0.
74 μm, which is about half of 1.6 μm of CD.

On the other hand, the optical pickup device also has a laser beam wavelength of 640 nm to 670
The one as short as nm is used. 770 nm for CD
Light having a long wavelength of up to 810 nm is used. Furthermore, in the optical system, in order to read the recorded information of the DVD, light whose beam spot is sufficiently small and narrowed down is required. On the other hand, when reading recorded information on a CD, it is necessary that the light be a beam spot adapted to the track interval of the CD.

[0005] By the way, there is a demand for an optical pickup device for reading recorded information of a DVD to have compatibility so that a recorded signal of a CD can also be read. For this purpose, as a light source for emitting laser light, a light source capable of obtaining a laser beam wavelength that can be adapted to read recorded information on DVD or a laser light for forming a beam whose spot is sufficiently small for reading recorded information on DVD is used. Optical system is required.

On the other hand, an optical pickup device having two light sources, one for a CD and the other for a DVD, has been considered in order to support both DVDs and CDs and to reduce the size. FIG. 4 is a diagram illustrating a main part of the optical disc device 1. The disk rotation drive unit 2 of the optical disk device 1 has first substrates having different substrate thicknesses.
The optical disk (DVD) and the second optical disk (CD) are selectively mounted. In FIG. 4, reference numeral 3 denotes an optical pickup device.

[0007] The optical pickup device 3 irradiates the information recording surface of the optical disk mounted thereon with laser light. The optical pickup device 3 is reciprocally movable in the radial direction of the optical disk so as to face the information recording surface of the mounted disk at an interval (in the directions indicated by arrows W1 and W2).
Is to be guided to.

FIGS. 5 and 6 show the optical pickup device 3. FIG. In the figure, reference numeral 10 denotes an optical base. In the figure, reference numeral 11 denotes a first light source for outputting semiconductor laser light (wavelength 650 nm), which is attached to the optical base 10. The laser light output from the first light source 11 passes through the focus error detecting element 12, travels through the cube-shaped beam splitter 13, and passes through the collimator lens 1.
Go through 4. The focus error detector 12 includes the beam splitter 1
The light on the return path, which has been reversed from the third side, is diffracted, and
It is intended to lead to. First light source 11 and photodetector 1
7 is integrated as a unit 18.

In the figure, reference numeral 21 denotes a semiconductor laser beam (wavelength 6).
50 nm), and the optical base 1
0 is attached. The laser light output from the second light source 21 passes through the focus error detecting element 22, travels through the cube beam splitter 13, and passes through the collimator lens 14. The focus error detector 22 is for diffracting the light on the return path that has returned in the backward direction from the beam splitter 13 side and guides the light to the photodetector 27. The second light source 21 and the photodetector 27 are integrated as a unit 28.

The beam splitter 13 converts the laser light from the first light source 11 and the laser light from the second light source 21 into the same output direction in the forward path (the collimator lens 14).
Side) and output. Further, the beam splitter 13 outputs the reflected light of the return path, which has been reversed from the same output direction, to the first and second light sources 11 and
It branches and leads to the 21 side.

The light emitted from the collimator lens 14 is
The objective lens 16 is started up by the reflection mirror 15.
And a beam spot is formed on the information recording surface of the optical disk. The light reflected from the information recording surface of the optical disk passes through the return path of the objective lens 16, the reflection mirror 15, and the collimator lens 14 and enters the beam splitter 13.

When the first light source 11 is used, the beam splitter 13 guides the reflected light to the focus error detecting element 12 side. When the light source 21 is used, the beam splitter 13 13 guides the reflected light to the focus error detection element 22 side.

The light output from the focus error detecting element 12 is guided to a light detector 17. When the light source 21 is used, the light output from the focus error detecting element 22 is guided to the photodetector 27.

The objective lens 16 provides a control current to the tracking coil 31 and the focusing coil 32 of the position control unit 30, controls the electromagnetism, and drives the actuator to physically control the position in the tracking direction and the focusing direction. Is done.

[0015]

The optical disk device provided with the above-mentioned conventional optical pickup device has the following problems. That is, in order to reduce the thickness of the entire optical disc device, the optical pickup device also needs to be designed to be thin. On the other hand, the reflection mirror 15 needs a certain length of the reflection surface 15a because the laser light moves on the reflection surface 15a. Therefore, the height direction cannot be cut, and the reflecting mirror 15 is formed by making a hole in the optical base 10 and attaching the reflecting mirror 15 from the side surface 15b side of the reflecting mirror 15. In addition, since other components such as the objective lens 16 are installed at a high density near the position where the reflection mirror 15 is provided, even if the reflection mirror 15 can be installed in design, each member may be installed for convenience of assembly. Had to be sharpened. For this reason, assembling becomes difficult, it takes time, and accurate installation is difficult.

Accordingly, it is an object of the present invention to provide an optical pickup device in which a reflection mirror can be easily attached to an optical base even if the thickness is reduced. Also,
SUMMARY OF THE INVENTION An object of the present invention is to provide an optical disk device in which the overall shape of the optical pickup device is reduced in size corresponding to a thinned optical pickup device.

[0017]

In order to solve the above-mentioned problems and to achieve the object, the invention according to the first aspect is characterized in that a light source for emitting a laser beam for irradiating an optical disk is mounted on a base. A holder body having a hole through which the laser beam passes, and a support member having a base end attached to the holder body and a distal end attached to an optical component for changing the direction of the laser beam. And was prepared.

According to a second aspect of the present invention, in the first aspect of the invention, another optical component is attached to the holder main body. According to a third aspect of the present invention, in the second aspect, the other optical component is attached to the hole.

According to a fourth aspect of the present invention, there is provided an optical pickup device having a light source for generating a laser beam for irradiating an optical disk, and an objective lens on which the laser beam emitted from the light source is incident. A light source that is attached to the base and emits the laser light, a holder body that is attached to the base and has a hole through which the laser light passes, and a base end side of which is attached to the holder body and a distal end thereof. A supporting member attached to an optical component for changing a direction of the laser beam.

According to a fifth aspect of the present invention, there is provided an optical disc apparatus in which an optical pickup device having a light source for emitting a laser beam reproduces or records a signal by irradiating the optical disc with the light source, and supports the light source and the optical components. A base, a holder body attached to the base and having a hole through which the laser light is formed, and an optical element for mounting the base end side of the holder body and changing the direction of the laser light at the tip end side. And a support member attached to the component.

As a result of taking the above-described measures, the following operation occurs. In other words, according to the first aspect of the present invention, it is not necessary to provide a hole or the like for attaching the optical component to the base, and the optical component can be easily positioned.

According to the second aspect of the present invention, the assembly work can be saved. According to the third aspect of the invention, the other optical component is attached to the hole. In the invention described in claim 4, it is not necessary to provide a hole or the like for attaching the optical component to the base, so that the optical component can be easily positioned and the overall thickness can be reduced.

According to the fifth aspect of the present invention, there is no need to provide a hole or the like for attaching an optical component to the base, so that the optical component can be easily positioned and the overall thickness can be reduced. .

[0024]

1A and 1B are views showing an optical pickup device 30 according to one embodiment of the present invention. Note that, in FIG. 1, the same functional portions as those in FIG. 5 are denoted by the same reference numerals.

FIG. 5 is a perspective view showing a first embodiment of the optical pickup device 40. As shown in FIG. Optical pickup device 40
Has an optical base 10. On the optical base 10, a first semiconductor laser light (wavelength 650 nm) is output.
Light source 11, focus error detecting element 12, and photodetector 17
Are provided. The first light source 11 and the light detector 17 are integrated as a unit 18. Note that the focus error detecting element 12 diffracts the returning light returning from the beam splitter 13 side, which will be described later, by making the incident light go straight or refracted in accordance with the polarization direction by using the diffraction effect of the hologram. In addition, it has a function of leading to the photodetector 17.

On the optical base 10, a second light source 21 for outputting a semiconductor laser light (wavelength 650 nm) is provided.
A focus error detection element 22 and a photodetector 27 are provided. The second light source 21 and the light detector 27 are connected to a unit 28
It is integrated as. Note that the focus error detection element 22
Uses the diffraction effect of a hologram to make incident light go straight or refracted in accordance with the direction of polarization, thereby diffracting backward light returning from the beam splitter 13 side and guiding it to the photodetector 27. have.

Further, a cube-shaped beam splitter 13 is provided on the optical base 10. The beam splitter 13 guides and outputs the laser light from the first light source 11 and the laser light from the second light source 21 toward the same output direction on the outward path (to the collimator lens 14). Further, the beam splitter 13 branches and guides the reflected light on the return path, which has returned in the backward direction from the same output direction, to the first and second light sources 11 and 21 that have emitted the respective reflected lights.

In FIG. 1, reference numeral 50 denotes an optical holder attached to the optical base 10. Optical holder 10
Is a holder main body 51 fixed to the optical base 10, a base end side is attached to the holder main body 51 side, and a front end side is a side surface 15b of the reflection mirror 15 (optical component).
And a support member 52 attached to the main body. Also,
At the center of the holder body 51, a hole 51a through which laser light passes is provided, and the collimator lens 14 is attached. The reflection mirror 15 and the collimator lens 1
Numerals 4 are respectively bonded to the support member 52 and the holder main body 51 with an adhesive, and thereafter, the holder main body 51 is bonded and fixed to the optical base 10.

Since the collimator lens 14 has a property of converging a laser beam as a diffused light, it is used for various purposes such as adjusting the degree of diffusion and obtaining a converged light or a parallel light.

On the other hand, reference numeral 30 in FIG. 1 denotes a position control unit. The position control unit 30 applies a control current to the tracking coil 31 and the focusing coil 32, controls the electromagnetism, and drives the actuator to thereby control the objective lens 1
6 is performed. This position control is physically performed in the tracking direction indicated by the illustrated arrow Tr and the focusing direction indicated by the arrow Fo.

The optical pickup device 40 thus configured operates as follows. That is, the first light source 1
The laser light output from 1 passes through the focus error detection element 12, travels through the cube-shaped beam splitter 13, and passes through the collimator lens 14.

The light emitted from the collimator lens 14 is
The objective lens 16 is started up by the reflection mirror 15.
And a beam spot is formed on the information recording surface of the optical disk. The light reflected from the information recording surface of the optical disk passes through the return path of the objective lens 16, the reflection mirror 15, and the collimator lens 14 and enters the beam splitter 13.

The beam splitter 13 guides the reflected light on the return path, which has returned in the backward direction, to the first and second light sources 11 and 21 from which the reflected light has been emitted. Therefore, when the first light source 11 is used, the beam splitter 13 guides the reflected light to the focus error detecting element 12 side, and when the light source 21 is used, the beam splitter 13 detects the reflected light for the focus error detection. It is led to the element 22 side.

When the first light source 11 is used,
The light output from the focus error detection element 12 is
It is led to. When the second light source 21 is used, the light output from the focus error detecting element 22 is guided to the photodetector 27.

As described above, the reflecting mirror 15 is attached to the optical base 10 via the optical holder 50.
Since no space is required for mounting 5, the overall thickness can be reduced. Further, the positioning can be easily performed, and the reflection mirror 15 can be positioned with high accuracy.

FIG. 2 is a view showing a modification of the above-described optical pickup device. That is, in this modification, the optical holder 60 is used instead of the optical holder 50. The optical holder 60 includes a holder main body 61 fixed to the optical base 10, a support member 62 having a base end attached to the holder main body 61 and a distal end attached to the side surface 15 b of the reflection mirror 15, and a holder main body 61. And a second support member 63 that holds the beam splitter 13. A hole 51a through which laser light passes is provided at the center of the holder main body 61, and the collimator lens 14 is attached to the hole 51a. In this modification, the same effect as in the above-described embodiment can be obtained.

FIG. 3A is a perspective view showing still another modified example of the optical holder incorporated in the optical pickup device described above. In this modification, an optical holder 70 is used instead of the optical holder 50.

The optical holder 70 has a holder main body 71 fixed to the optical base 10, a base end side attached to the holder main body 71 side, and a front end side reflecting mirror 15.
And a support member 72 attached to the reflection surface 15b. Note that the support member 72 is adhered to a position on the reflection surface 15b where the laser light does not move.
Does not block the laser light.

FIG. 3B is a schematic view of the reflection surface 15a of the optical pickup device 40 of FIG. 2 as viewed from the light source side.
In the case of FIG. 2, the optical axis enters obliquely with respect to the feed direction of the optical pickup device 40. At this time, the profile of the light spot L on the reflection surface 15a swings along the direction of the arrow α according to the tracking operation of the objective lens 16. Therefore, by arranging the support member 72 in a portion that does not affect the swing, normal operation can be performed.

On the other hand, when a light beam from the light source is incident perpendicularly to the feed direction of the optical pickup device 40, the profile of the light spot L on the reflecting surface 15a swings in the direction of arrow β. Therefore, in this case, by providing the ends of the support member at the four corners as shown in FIG.

As shown in FIG. 3D, it can be realized by bonding two support members 72 to the lower portion of the mirror 15, and in this case, it is possible to contribute to further reduction in thickness.

The present invention is not limited to the embodiment. For example, a prism or the like that can change the direction of laser light may be used instead of the reflection mirror in the above-described embodiment. In addition, it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0043]

According to the present invention, there is no need to provide a hole or the like for attaching an optical component to the base, and the optical component can be easily positioned. Further, the dimension in the height direction can be saved, and the thickness can be reduced.

[Brief description of the drawings]

FIG. 1 is a view showing an optical pickup device incorporated in an optical disk device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a modification of the optical pickup device.

FIG. 3 is a diagram showing an optical holder according to a modification of the optical pickup device.

FIG. 4 is a plan view showing a main part of the optical disk device.

FIG. 5 is a perspective view showing a conventional optical pickup device incorporated in the optical disc device.

FIG. 6 is an explanatory view showing the principle of the optical pickup device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Optical disk device 15 ... Reflection mirror 40 ... Optical pickup device 50, 60, 70 ... Optical holder 51, 61, 71 ... Holder main body 52, 62, 63 ... Support member

Claims (5)

[Claims] An optical disk is mounted on a base on which a light source for emitting laser light for irradiating the optical disk is mounted, and a holder body having a hole through which the laser light passes is formed, and a base end side is mounted on the holder body. And a support member mounted on an optical component for changing the direction of the laser beam. 2. The pickup device according to claim 1, wherein another optical component is attached to the holder main body. 3. The pickup device according to claim 2, wherein the other optical component is attached to the hole. 4. An optical pickup device comprising: a light source for generating a laser beam for irradiating an optical disc; and an objective lens on which the laser beam emitted from the light source is incident. A light source that emits light, a holder body attached to the base and formed with a hole through which the laser light passes, a base end side of which is attached to the holder body, and a tip side of the holder changes the direction of the laser light. An optical pickup device, comprising: a support member attached to an optical component for use. 5. An optical disc apparatus in which an optical pickup device having a light source for emitting a laser beam reproduces or records a signal by irradiating an optical disc with a light, a base for supporting the light source and the optical component, and a base attached to the base. A holder body having a hole through which the laser light passes, and a support member having a base end attached to the holder body and a distal end attached to an optical component for changing the direction of the laser light. An optical disk device comprising: