JP2003168240A - Optical pickup manufacturing method, optical pickup device, and optical disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently assemble optical elements into an optical pickup device. <P>SOLUTION: In the middle of the assembling process of optical elements into an optical pickup device, a light flux is emitted from a semiconductor laser unit with the outgoing direction of the light flux detected (step 405, 413) and with the optical axis deviation of the light flux corrected which is due to the shift of the outgoing direction from a reference direction (step 407, 415). As a result, there is no need of executing a fine adjustment of one or more optical elements or redoing the assembling itself, for the purpose of correcting the optical axis deviation after completion of the assembling. Thus, it is possible to efficiently assemble optical elements into the optical pickup device. In addition, since the optical axis deviation is corrected on the basis of the detection result of the outgoing direction of the light flux emitted from the semiconductor laser unit, the optical axis deviation can be corrected simply and surely even by an unskilled worker, in which case no holder or the like of a complicated structure is necessary. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an optical pickup device, an optical pickup device, and an optical disk device, and more specifically, at least reproducing of recording, reproducing, and erasing information on an optical recording medium. The present invention relates to a method for manufacturing an optical pickup device used for that purpose, an optical pickup device manufactured by the manufacturing method, and an optical disk device including the optical pickup device.

[0002]

2. Description of the Related Art In an optical disk device, for example, a CD (comp
optical discs such as act discs) and DVDs (digital versatile discs), especially CD-RWs (CD-rewritable), D
Information is recorded on a rewritable optical recording medium such as VD + RW (DVD + rewritable) by irradiating the recording surface with a minute spot of laser light, and reproducing the information based on the reflected light from the recording surface. It is carried out. The optical disc device is provided with an optical pickup device for irradiating the recording surface of the optical recording medium with laser light and receiving reflected light from the recording surface.

Generally, an optical pickup device guides a light source, an optical system for guiding a light beam emitted from the light source to a recording surface of an optical recording medium, and a returning light beam reflected by the recording surface to a predetermined light receiving position, and a light receiving device. It is provided with a light receiving element or the like arranged at a position. They are assembled in the housing of the optical pickup device.

In recent years, the capacity of optical recording media has dramatically increased, and the recording speed has been increased. Accordingly, the optical pickup device can be more quickly and
Moreover, there is an increasing demand for accurately irradiating a minute spot to a predetermined position on the recording surface of an optical recording medium.

For example, the optical axis of a light beam emitted from a light source (hereinafter referred to as "emission optical axis") is the designed optical axis (hereinafter referred to as "optical axis").
If it does not match the "ideal optical axis"), the intensity distribution of the light emitted from the light source is different from the designed intensity distribution, so the light intensity distribution becomes asymmetric on the recording surface of the optical recording medium, and There is an inconvenience that proper recording and reproduction cannot be performed. In some cases, wavefront aberration may occur, the spot may not be fully stopped, and the light quantity (so-called power) of the irradiation light on the recording surface may decrease. This is especially true for DV recorded at high density.
It is not suitable for an optical disc device for recording and reproducing D, an optical disc device for high-speed writing that requires a large power, and the like.

In order to improve such inconvenience, even in the past, a proposal for assembling the light source and the optical system into the housing of the optical pickup device so as to reduce the difference between the outgoing optical axis and the ideal optical axis, that is, the optical axis shift. Has been done in various ways.

For example, Japanese Unexamined Patent Publication No. 9-219033 discloses a holder used when a semiconductor laser unit as a light source is attached to a housing of an optical pickup device.
There is disclosed a laser holder device capable of adjusting the rotation of the semiconductor laser unit in addition to the two-dimensional position adjustment of the semiconductor laser unit by combining a member having a convex portion and a member having a concave portion. This laser holder device corrects the position and orientation of the semiconductor laser unit that causes the deviation of the emission optical axis when the semiconductor laser unit is assembled.

[0008]

However, in the invention described in Japanese Patent Laid-Open No. 9-219033, the structure of the holder itself becomes complicated, and the optical pickup device including the holder becomes large in size and high in cost. There was an inconvenience.

As a means for improving this inconvenience, for example, Japanese Unexamined Patent Application Publication No. 2001-134951 includes a mounting surface for mounting a semiconductor laser unit and a mounting surface for mounting on a housing of an optical pickup device. There is disclosed an optical pickup device using a holder (adapter) having a predetermined angle between a mounting surface and a mounting surface. According to this invention, the structure of the holder is simplified, and by rotating the holder, the emission optical axis of the laser light from the semiconductor laser unit can be brought close to the ideal optical axis.

However, the adjustable amount of the deviation of the optical axis of the outgoing optical axis, that is, the amount of correction of the deviation of the outgoing direction of the laser light is determined by the angle formed between the mounting surface and the mounting surface of the holder, and therefore the semiconductor. It is difficult to deal with all variations in the tilt of the laser unit.

The present invention has been made under the above circumstances, and a first object of the present invention is to provide an optical pickup device capable of surely correcting an optical axis shift without using a holder having a complicated structure. It is to provide a manufacturing method.

A second object of the present invention is to provide an optical pickup device in which the optical axis shift is corrected and the occurrence of wavefront aberration and the reduction of power are reduced.

A third object of the present invention is to provide an optical disk device capable of reproducing information recorded on an optical recording medium with high density with high accuracy.

[0014]

According to a first aspect of the present invention, there is provided an optical pickup device for manufacturing an optical pickup device which is used for at least reproduction of recording, reproducing and erasing of information on an optical recording medium. A manufacturing method, which comprises a light source unit and an optical system for guiding a light beam emitted from the light source unit to a recording surface of the optical recording medium and for guiding a return light beam reflected by the recording surface to a predetermined light receiving position. An assembling step of assembling each optical element in a predetermined positional relationship and arranging the first light receiving element at the light receiving position; and from the light source unit at any point until the processing of the assembling step is completed. A detection step of emitting a light beam and detecting the emission direction of the light beam; and the optical system based on the detected emission direction during the process of the assembling step. A method for manufacturing an optical pickup apparatus comprising: driving at least one specific optical elements constituting the correction process and for correcting the optical axis deviation of the light beam caused by the deviation from the reference direction of the emission direction.

According to this, the light source unit and the optical system for guiding the light beam emitted from the light source unit to the recording surface of the optical recording medium and for guiding the return light beam reflected by the recording surface to a predetermined light receiving position. Each optical element constituting the above is assembled in a predetermined positional relationship, and the first light receiving element is arranged at the light receiving position (assembly step). At any point until the process of this assembling step is completed, a light flux is emitted from the light source unit and the emission direction of the light flux is detected (detection step). Then, in the middle of the process of the assembling step, at least one specific optical element that constitutes the optical system is driven based on the detected emission direction, and the optical axis of the light beam is deviated due to the deviation of the emission direction from the reference direction. Is corrected (correction step). Therefore, in the initial stage of the assembling process of the optical pickup device, the deviation of the optical axis of the light beam caused by the deviation of the emission direction of the light beam emitted from the light source unit from the reference direction is corrected. Further, in this case, since the optical axis deviation is corrected during the process of the assembling process, one or more optical elements may be finely adjusted or the assembly itself may be redone to correct the optical axis deviation after the assembly is completed. There is no need to do it. Therefore, the assembly can be performed efficiently. Further, since the optical axis shift is corrected based on the detection result of the emission direction of the light flux emitted from the light source unit, even an unskilled person can easily and surely correct the optical axis shift. In this case, a holder having a complicated structure is unnecessary.

In this case, the emission direction of the light beam can be detected by using a sensor such as CCD or PSD. However, for example, as in the manufacturing method according to claim 2, in the detecting step, the received light is received. It is possible to detect the emission direction of the light flux using the second light receiving element whose surface is divided into at least two. In such a case, the second
Since the light receiving surface of the light receiving element is divided into at least two, a signal corresponding to the amount of received light is output from each region (each divided region) of the light receiving surface. Therefore, it is possible to reliably detect the deviation of the emission direction of the emitted light beam from the light source unit based on the value of the difference signal formed by an appropriate combination of those signals. In this case, by driving at least one specific optical element so that the absolute value of the difference signal becomes equal to or less than a predetermined value, for example, substantially zero, there is an optical axis deviation that causes the emission optical axis to substantially match the ideal optical axis. Correction is possible.

Here, an appropriate combination of the signals output from each region (each divided region) of the light receiving surface according to the amount of received light is, for example, the first division when the light receiving surface is divided into two. A difference signal, which is a simple difference between the first signal from the area and the second signal from the second divided area, may be obtained. Further, for example, when the light receiving surface is divided into four, it is the difference between the sum of signals from two adjacent areas and the sum of signals from the remaining two adjacent areas among the four divided areas. It suffices to find the difference signal. In this case, by combining the regions, it is possible to obtain the optical axis shift in any of the directions of two orthogonal axes in the two-dimensional plane orthogonal to the ideal optical axis. In addition, even if the light receiving surface is divided into, for example, three or five, it is possible to combine signals so as to obtain a difference signal according to the deviation of the emission direction depending on how the light receiving surface is divided. .

In this case, as in the manufacturing method according to the third aspect, a condensing means for condensing a light beam incident on the light receiving surface of the second light receiving element is arranged in proximity to the light receiving surface. The method may further include steps. here,
"Proximity to the light receiving surface" means within a predetermined distance from the light receiving surface, and includes the case where the distance is zero, that is, the case where the light receiving surface is in contact with the light receiving surface. In such a case, since the cross-sectional area of the light beam incident on the light receiving surface on the light receiving surface can be reduced by the action of the light condensing means, an element having a small overall light receiving surface can be used as the second light receiving element. For this reason, it is possible to detect a signal according to the amount of incident light, that is, the above-mentioned difference signal, which is hardly affected by noise and has a good S / N ratio, and it is possible to improve the detection accuracy in the emission direction.

In each of the manufacturing methods described in claims 2 and 3, a light receiving element different from the first light receiving element can be used as the second light receiving element, but the manufacturing method according to claim 4 As described above, the second light receiving element is
It can be assumed that the light receiving element is the same as the above light receiving element. In such a case, since the first light receiving element arranged in the optical pickup device also serves as the second light receiving element for detecting the emitting direction, it is necessary to separately provide a light receiving element for detecting the emitting direction. Therefore, the cost can be reduced.

In each of the above-mentioned manufacturing methods, the driving of the specific optical element for correcting the optical axis shift of the light beam due to the shift of the emission direction from the reference direction is manually performed. Although it can be performed, for example, as in the manufacturing method according to claim 5, in the correction step, a drive device that drives the specific optical element based on the detected deviation in the emission direction can be used. . In such a case, the drive device drives the specific optical element based on the deviation of the emission direction, so that the optical axis deviation can be automatically corrected.

In each of the manufacturing methods described in claims 1 to 4, as in the manufacturing method described in claim 6, in the detecting step, the emission directions are detected for a plurality of light beams having different wavelengths. When the emission directions of the plurality of light beams are different by a predetermined angle or more, a step of replacing the light source unit may be further included in the process of the assembling step. In such a case, after the assembly is completed (after the pickup device is manufactured), it is proved difficult to correct the deviation of the emission directions of the light beams from the plurality of light source units, and there is a problem such as disassembly and reassembly. There is no danger of it occurring.

The invention according to claim 7 is an optical pickup device manufactured by the method for manufacturing an optical pickup device according to claims 1 to 6.

According to this, since the optical pickup device is manufactured by the manufacturing method according to any one of claims 1 to 6, at the manufacturing stage, the deviation of the emission direction of the light beam emitted from the light source unit from the reference direction is prevented. The deviation of the optical axis between the output optical axis and the ideal optical axis caused by the correction is corrected. Therefore, it is possible to reduce the deviation of the optical axis of the light beam applied to the recording surface of the optical recording medium as much as possible, and to suppress the occurrence of wavefront aberration and the reduction of power as much as possible.

The invention according to claim 8 is an optical disk device for performing at least reproduction among information recording, reproduction, and erasing on an optical disk, and the optical pickup device according to claim 7; An optical disc device, comprising: a processing device that performs at least reproduction of the information recording, reproduction, and erasing by using an output signal of the first light receiving element that constitutes a pickup device.

According to this, the optical axis deviation is reduced as much as possible,
Since the optical pickup device according to claim 7 is provided in which generation of wavefront aberration and reduction of power are suppressed as much as possible, DV
Even for an optical disc in which information is recorded at a high density such as D, it is possible to always irradiate a fine spot at a predetermined position on the recording surface of the optical disc with accuracy. That is, it becomes possible to accurately reproduce the information recorded on the optical recording medium that has been recorded at high density. Of course, when the optical disk device is of a type that records information in addition to reproducing information, high-speed recording operation becomes possible.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION << First Embodiment >> A first embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a schematic configuration of an optical disc device 20 according to the first embodiment, which is equipped with an optical pickup device according to the present invention.

The optical disk device 20 shown in FIG.
Is a spindle motor 22 for rotationally driving an optical disk 15 as an optical recording medium, and an optical pickup device 2.
3, laser control circuit 24, encoder 25, motor driver 27, reproduction signal processing circuit 28, servo controller 33, buffer RAM 34, buffer manager 37, interface 38, ROM 39, CPU 4
0 and RAM 41 and the like. It should be noted that the arrows in FIG. 1 show typical flows of signals and information, and do not show all the connection relations of each block.

The optical pickup device 23 is a device for irradiating the recording surface of an optical recording medium such as the optical disk 15 with a laser beam and receiving the reflected light from the recording surface. The configuration of the optical pickup device 23 will be described later in detail.

The reproduction signal processing circuit 28 converts a current signal which is an output signal of the optical pickup device 23 into a voltage signal, and based on the voltage signal, a wobble signal, an RF signal including reproduction information and a servo signal (focus error). Signal or track error signal). Then, in the reproduction signal processing circuit 28, the ATIP (Abso
lute Time In Pre-groove) Extract information and sync signal. The ATIP information extracted here is output to the CPU 40, and the synchronization signal is output to the encoder 25. Further, the reproduction signal processing circuit 28 performs error correction processing and the like on the RF signal, and then stores it in the buffer RAM 34 via the buffer manager 37. The focus error signal and the track error signal are output from the reproduction signal processing circuit 28 to the servo controller 33.

The servo controller 33 generates a control signal for controlling the focusing actuator of the optical pickup device 23 based on the focus error signal, and a control signal for controlling the tracking actuator of the optical pickup device 23 based on the track error signal. To generate. Both control signals are output from the servo controller 33 to the motor driver 27.

The buffer manager 37 manages the storage of data in the buffer RAM 34 and notifies the CPU 40 when the stored data amount reaches a predetermined value.

The motor driver 27 drives the focusing actuator and the tracking actuator of the optical pickup device 23 based on the control signal from the servo controller 33. Further, in the motor driver 27, based on the instruction from the CPU 40, the spindle motor 22 is controlled so that the linear velocity of the optical disk 15 becomes constant.
To control. Further, in the motor driver 27, the CPU
Based on the instruction from 40, the seek motor of the optical pickup device 23 is driven to control the position of the optical pickup device 23 in the sledge direction (radial direction of the optical disk 15).

In the encoder 25, based on an instruction from the CPU 40, the data stored in the buffer RAM 34 is taken out via the buffer manager 37, an error correction code is added, etc., and write data to the optical disk 15 is created. . Then, the encoder 25 outputs the write data to the laser control circuit 24 in synchronization with the synchronization signal from the reproduction signal processing circuit 28 based on the instruction from the CPU 40.

The laser control circuit 24 controls the output of the semiconductor laser chip 51a (see FIG. 3) of the optical pickup device 23 based on the write data from the encoder 25.

The interface 38 is a bidirectional communication interface with a host (for example, a personal computer), and is an ATAPI (AT Attachment Pack).
et Interface) and SCSI (Small Computer System)
Interface) and other standard interfaces.

The ROM 39 stores a program written in a code readable by the CPU 40.

The CPU 40 controls the operation of each of the above parts in accordance with the program stored in the ROM 39, and temporarily stores the data and the like necessary for the control in the RAM 41.

In this embodiment, the reproduction signal processing circuit 28,
Encoder 25, laser control circuit 24, and C
The PU 40 constitutes a processing device that records information on the optical disc 15 and reproduces information recorded on the optical disc.

Next, the structure of the optical pickup device 23 will be described with reference to FIGS.

As shown in FIG. 2, the optical pickup device 23 includes a semiconductor laser unit 51 as a light source unit, a collimator lens 52, a reflection mirror 53, a polarization beam splitter 54, a λ / 4 plate 55, and a deflection prism 5.
6, which includes an objective lens 57, a condenser lens 58, and the like, guides the light beam (laser beam) emitted from the semiconductor laser unit 51 to the recording surface of the optical disc 15, and receives the return light beam reflected by the recording surface in a predetermined manner. Optical system for guiding to the position and the first light receiving element 59 arranged at the light receiving position
It has and. The semiconductor laser unit 51, the optical system, and the first light receiving element 59 are assembled in a housing of the optical pickup device in a predetermined positional relationship. In addition,
This will be described later. Reference numeral LR in FIG. 2 indicates the ideal optical axis of the light beam emitted from the semiconductor laser unit 51.

As shown in FIG. 3, the semiconductor laser unit 51 includes a semiconductor laser chip 51a that emits laser light, a stem 51b that holds the semiconductor laser chip 51a, and laser light emitted from the semiconductor laser chip 51a to the outside. Opening part (hereinafter referred to as "exit window")
Cover 51 for protecting the semiconductor laser chip 51a
It is configured to include c and the like.

As the first light receiving element 59, a four-divided light receiving element is used as in the case of an ordinary optical disk device. The first light receiving element 59 receives the reflected light from the recording surface of the optical disc 15 and, like the ordinary optical pickup device, a signal including wobble signal information, reproduction data information, focus error information, track error information and the like. Is output.

Returning to FIG. 2, the operation of the optical pickup device 23 configured as described above will be described. Linearly polarized light emitted from the semiconductor laser unit 51 (polarized light (P polarized light parallel to the incident surface of a polarization beam splitter described later) (P The polarized light) is converted into a substantially parallel light by the collimator lens 52, its optical axis is bent in the −X direction by the reflection mirror 53, and is incident on the polarization beam splitter 54. The light beam that has passed through the polarization beam splitter 54 is circularly polarized by the λ / 4 plate 55, its optical axis is bent in the + Y direction by the deflection prism 56, and is slightly reflected on the recording surface of the optical disc 15 via the objective lens 57. It is collected as a spot.

The reflected light reflected by the recording surface of the optical disk 15 becomes circularly polarized light in the opposite direction to the outward path, and the objective lens 5
In 7 again, the light is made into substantially parallel light, is deflected in the + X direction by the deflecting prism 56, and is converted into linearly polarized light (S polarized light) orthogonal to the outward path by the λ / 4 plate 55. Then, the reflected light is deflected in the −Z direction by the polarization beam splitter 54, and is received by the first light receiving element 59 via the condenser lens 58. From the first light receiving element 59, a current (current signal) according to the amount of light received
Is output to the reproduction signal processing circuit 28 of FIG.

Next, regarding the method of manufacturing the optical pickup device 23 configured as described above, along the flowchart of FIG. 4 showing the procedure for manufacturing the optical pickup device 23, and referring to other drawings as needed, explain.

First, in step 401 of FIG.
As shown in (A), the semiconductor laser unit 51,
The collimator lens 52, the reflection mirror 53, and the deflection prism 56 are attached to the housing 60 of the optical pickup device. At this time, the semiconductor laser unit 51 is assembled to the housing 60 while being held by the holder 61.

In step 403 of FIG. 4, the detection light receiving element 62 as the second light receiving element is moved to a predetermined position on the optical path between the reflecting mirror 53 and the deflecting prism 56, as shown in FIG. 5 (A). Place in position. Here, a monitor 64 is connected to the detection optical element 62 via a measurement control device 63, as shown in FIG. In the present embodiment, the measuring device 70 is configured by the detection optical element 62, the measurement control device 63, and the monitor 64. Here, as the detection light-receiving element 62, for example, its light-receiving surface is divided into two vertically (Z-axis direction) along a dividing line in the XY plane including the ideal optical axis in FIG. A divided light receiving element is used. In the following, the detection light receiving element 62
As shown in FIG. 6B, a two-divided light receiving element including a first partial light receiving element 62a and a second partial light receiving element 62b is used.

As is apparent from FIG. 5A and the above description, the predetermined position is a predetermined position where the ideal optical axis is orthogonal to the dividing line of the detection light receiving element 62.
In this case, the housing 60 has a wall on one side in the Y-axis direction as shown in FIG.
As shown in (B), a U-shaped slide guide 60a protruding inward is formed. Therefore, the detection light receiving element 62 is accurately positioned at the predetermined position along the slide guide 60a.

In step 405 of FIG. 4, laser light is emitted from the semiconductor laser unit 51. In this case, if the emission direction is deviated to the + X direction, the optical axis of the laser light becomes
As indicated by the solid line in FIG. 6A, the light flux that does not match the ideal optical axis LR indicated by the alternate long and short dash line and that has passed through the collimator lens 52 is detected by shifting in the −Z direction with respect to the dividing line. Is incident on the light receiving element 62 (see FIG. 6B). As a result, the output signal of the first partial light receiving element 62a (referred to as the signal Sa) and the output signal of the second partial light receiving element 62b (the signal S
The difference signal ΔS _Z = Sa−Sb from the measurement control device 63 is displayed on the screen of the monitor 64 together with the reference level (zero level). In this case, monitor 6
On the screen of No. 4, the reference level and the signal waveform of the negative level substantially parallel to the reference level are displayed. The measurement control device 63 has a built-in operational amplifier that inputs the signals Sa and Sb and outputs the difference signal ΔS _Z.

In step 407 of FIG. 4, the position of the reflecting mirror 53 is adjusted while referring to the display on the screen of the monitor 64. The adjustment of the reflection mirror 53 here is performed with reference to FIG.
The adjustment screw 65 provided on the back surface side of the reflection mirror 53 (the surface opposite to the reflection surface) is rotated counterclockwise (or clockwise) as shown in FIG. The adjustment screw 65 in FIGS. 5A, 6A, 6C, etc. is an adjustment mechanism that drives the reflection mirror 53 in the arrow R or arrow L direction shown in FIG. 5A. It is a conceptual diagram shown. Therefore, the reflecting mirror 53 is always biased in the direction of the arrow L shown in FIG. 5A by a biasing means (not shown), and the reflecting mirror 53 is moved in accordance with the position of the adjusting screw as the adjusting mechanism. Alternatively, the reflecting mirror 53 may be arranged at the position 53 ′ shown in FIG. 5 (A) at the initial stage of assembling, and the reflecting mirror 53 may be moved in the direction of arrow R by an adjusting screw as an adjusting mechanism. Also good. Alternatively, for example, the reflection mirror may be driven via an attachment or the like which is provided on the back surface side of the reflection mirror 53 and which makes three-point contact with the back surface of the reflection mirror 53. In short, the adjusting mechanism may have any configuration as long as the reflecting mirror 53 can be driven in the arrow R or arrow L direction shown in FIG. The driving direction of the reflection mirror 53 may be the X-axis direction or the Z-axis direction. As described above, since various mechanisms can be adopted as the mechanism for driving the reflection mirror 53, the adjustment screw 65 will be hereinafter referred to as an “adjustment mechanism 65”.

In any case, the adjusting mechanism 65
The difference signal ΔS on the screen of the monitor 64. _ZIs almost the standard level
If the reflection mirror 53 can be adjusted so that
Yes. Therefore, as shown in FIG.
The optical axis of the light beam emitted from the unit 51 is the ideal optical axis (one
(Indicated by the dotted chain line) and is behind the reflection mirror 53.
As a result of the misalignment of the optical axis, as shown in FIG.
When the luminous flux incident on the element 62 is shifted to the −Z side,
The reflection mirror 53 is adjusted by adjusting as described above.
The rear optical axis is at least Z as shown in FIG.
Regarding the axial direction, it is possible to match the ideal optical axis LR.
It becomes Noh. As a result, as shown in FIG.
The light flux reflected by the reflecting mirror 53 is detected by the light receiving element 62 for detection.
Will be incident on the central part of.

When the adjustment of the reflecting mirror 53 is completed as described above, in step 409 of FIG. 4, the detection light receiving element 62 is removed from the optical path.

When the deviation in one direction (Z-axis direction) of the optical axis is corrected as described above, the correction of the optical axis deviation in the direction orthogonal to the one direction is then executed as follows.

That is, in step 411 of FIG. 4, as shown in FIG. 7, the detection light receiving element 62 is arranged at a predetermined position on the optical path behind the deflection prism 56. In this case, as can be seen from FIG. 7, the detection light receiving element 62 is arranged in a state where the dividing line thereof coincides with the Z-axis direction orthogonal to the ideal optical axis. Also in this case, a U-shaped (U-shaped) slide guide similar to the slide guide 60a shown in FIG. 5B is formed on the + Z side wall of the housing 60, and the detection light receiving The element 62 is arranged at a predetermined position along this slide guide.

Returning to FIG. 4, in the next step 413, the semiconductor laser unit 51 is caused to emit a laser beam, and the above-mentioned difference signal obtained based on the detection result of the detection light receiving element 62 is passed through the measurement control device 63. And displays it on the screen of the monitor 64. In this case, when the optical axis is shifted in the + Y direction from the ideal optical axis LR indicated by the alternate long and short dash line as shown by the solid line in FIG. In addition, when the light is emitted from the deflection prism 56, the optical axis is deviated from the ideal optical axis in the −X direction.
For this reason, the luminous flux with respect to the detection light receiving element 62 is
The detection signal S in this case is incident as shown in FIG.
The relationship between Sa and Sb is Sa <Sb. Therefore, the difference signal becomes a negative signal.

In the next step 415, the adjusting mechanism 66 similar to the adjusting mechanism 65 described above is adjusted in the same procedure as in step 407 to move the deflecting prism 56 in the + Y direction by a predetermined amount (FIG. 8). (See (C)). This allows
As shown in FIG. 8D, the light flux is incident on the central portion of the detection light receiving element 62.

By the above processing, the optical axis coincides with the ideal optical axis in all the optical paths from the reflecting mirror 53 to the objective lens 57, and the optical axis deviation caused by the deviation of the emitting direction of the laser beam is almost completely corrected. It

The adjusting mechanism 66 includes the deflecting prism 56.
May be driven in the X-axis direction, or the deflection prism 56 may be driven in the axial direction orthogonal to the reflecting surface thereof.

After the position adjustment of the deflection prism 56 is completed as described above, in the next step 417, the detection light receiving element 62 is removed from the optical path behind the deflection prism 56.

In the next step 419, the remaining optical elements which have not been assembled so far (the polarization beam splitter 54, the λ / 4 plate 55, the objective lens 5 shown in FIG. 2) are used.
7, the condenser lens 58) and the first light receiving element 59
After assembling according to the design value in 0, the manufacturing of the optical pickup device 23 is completed by performing processing such as attaching a cover (cover) of the housing. At this time, each optical element, the semiconductor laser unit, and the first light receiving element 59 are
It is assembled in the ideal positional relationship shown in FIG.

As described in detail above, according to the method of manufacturing the optical pickup device of this embodiment, the semiconductor laser unit 51 and each optical element forming the optical system are predetermined in the assembling step of the optical pickup device. The first light receiving element 59 is arranged at the light receiving position of the returning light flux by the optical system. At any point until such processing is completed, for example, the semiconductor laser unit 51, the collimator lens 52, the reflection mirror 53,
When the deflection prism 56 is assembled to the housing 60 of the optical pickup device, a light beam is emitted from the semiconductor laser unit 51, and the emission direction of the light beam is detected using the detection light receiving element 62. Then, in the middle of the process of the assembling process, at least one of the reflection mirror 53 and the deflection prism 56, which is a specific optical element, is driven based on the detected emission direction, and the light flux caused by the deviation of the emission direction from the reference direction is emitted. Correct the optical axis shift. Therefore, in the initial stage of the assembling process of the optical pickup device, the deviation of the optical axis of the light beam caused by the deviation of the emitting direction of the light beam emitted from the semiconductor laser unit 51 from the reference direction (ideal optical axis direction) is corrected. Be seen. Further, in this case, since the optical axis deviation is corrected during the process of the assembling process, one or more optical elements may be finely adjusted or the assembly itself may be redone to correct the optical axis deviation after the assembly is completed. There is no need to do it. Therefore, the assembly can be performed efficiently.
Further, since the optical axis shift is corrected based on the detection result of the emission direction of the light flux emitted from the semiconductor laser unit 51, even an unskilled person can easily and surely correct the optical axis shift. . In this case, a holder having a complicated structure is unnecessary.

Further, the two-divided light receiving element is used as the detection light receiving element 6
Since the second partial light receiving element 62a and the second partial light receiving element 62b are used, the signals corresponding to the respective light receiving amounts are output. Therefore, it is possible to reliably detect the deviation in the emission direction of the emitted light beam from the semiconductor laser unit 51 based on the value of the difference signal between these signals. In this case, by driving the specific optical element so that the absolute value of the difference signal becomes substantially zero, for example,
It is possible to correct the deviation of the optical axis so that the outgoing optical axis substantially coincides with the ideal optical axis.

Further, since the optical pickup device 23 according to the present embodiment is manufactured by the manufacturing method described above, the optical axis shift between the emission optical axis and the ideal optical axis is corrected at the manufacturing stage. Therefore, it is possible to reduce the deviation of the optical axis of the light beam applied to the recording surface of the optical disc as much as possible, and suppress the occurrence of wavefront aberration and the reduction of power as much as possible.

Further, the optical disc device 2 according to the present embodiment.
At 0, the optical axis shift is reduced as much as possible, and the optical pickup device 23 in which the generation of the wavefront aberration and the reduction of the power are suppressed as much as possible is provided. Therefore, for an optical disc on which information is recorded at high density like a DVD. Even in this case, it is possible to always irradiate the predetermined position on the recording surface of the optical disc with a fine spot accurately. Therefore, it is possible to accurately reproduce the information recorded on the high-density recorded optical disc. It is also possible to support high-speed recording operation (writing operation).

The detection light receiving element is not limited to the two-divided light receiving element, and a four-divided light receiving element 62 'whose light receiving surface is divided into four along a cross-shaped dividing line as shown in FIG. 9 may be used. good. In such a case, the detection light receiving element 62 ′ is orthogonal to the ideal optical axis on the optical path behind the deflection prism 56,
A division in which the center of the cross-shaped dividing line coincides with the ideal optical axis and forms a boundary line between the first partial light receiving element 62a and the second partial light receiving element 62b, and the third partial light receiving element 62c and the fourth partial light receiving element 62d. It is desirable that the line pl be inserted with the line pl substantially aligned with the X axis. In this case, the first partial light receiving element 62
The output signal of a is Sa, the output signal of the second partial light receiving element 62b is Sb, the output signal of the third partial light receiving element 62c is Sc,
The output signal of the fourth partial light receiving element 62d is Sd, and the difference signal ΔS _Z ′ = {(Sa + Sb) − (Sc + Sd)} and ΔS _X ′ = {(Sa + Sc) − (Sb + Sd)} are set by the measurement control device 63. It may be calculated and displayed on the screen of the monitor 64 together with each reference level signal (zero level signal).

Then, by adjusting the adjusting mechanisms 65 and 66 so that ΔS _Z ′ and ΔS _X ′ are almost 0, the position adjustment of the reflecting mirror 53 and the deflecting prism 56, that is, the two-dimensional adjustment, can be performed by one measurement. It is possible to correct the optical axis shift in the direction. Therefore, the processes of steps 403 to 409 in FIG. 4 are unnecessary, and the above adjustment is performed in step 415. Therefore, the optical pickup device 23 can be manufactured more efficiently.

Further, as shown in FIG. 10A, in the vicinity of the light receiving surface of the detection light receiving element 62 '(or 62),
For example, a condensing lens 71 as a condensing unit is arranged, and the condensing point FP of the parallel light LB guided onto the light receiving element 62 ′ (or 62) is located behind the light receiving element 62 ′ (or 62). Also good. In such a case, as shown in FIG. 10 (B), the size of the light spot formed on the light receiving surface of the light receiving element 62 ′ (or 62) is smaller than that without the condenser lens 71 (SP1). Then, when the condenser lens 71 is present (SP2), it becomes smaller, so that it is possible to use an element having a small light receiving area as the detection light receiving element 62 '(or 62). In this case, the S / N ratio becomes good, and the detection accuracy of the deviation in the emission direction can be improved. The condenser lens 71 may be arranged in contact with the light receiving surface of the detection light receiving element, or may be arranged slightly apart. The point is that the light spot formed on the light receiving surface of the light receiving element for detecting the light flux should be smaller than in the case where the condenser lens 71 is not provided. In the former case, it is also possible to attach the condenser lens 71 on the light receiving surface of the detection light receiving element and integrate them in advance.

<< Second Embodiment >> Next, a second embodiment of the present invention will be described with reference to FIGS.

The second embodiment is characterized in that the above-mentioned adjustment of the optical axis shift is automatically performed. In addition, the configurations of the optical pickup device and the optical disc device are the same as those of the first embodiment described above. Therefore, in the following, differences from the first embodiment will be mainly described, and the same reference numerals will be used for the same or equivalent components as those in the first embodiment described above, and the description thereof will be simplified. Or it shall be omitted.

FIG. 11 is a flowchart showing a procedure for manufacturing the optical pickup device 23 according to the second embodiment.

In steps 501 and 503 of FIG. 11, the same processing as in steps 401 and 403 described above is performed. However, in step 501, together with the reflection mirror 53, the drive device 165 (see FIG. 12A) that drives the reflection mirror 53 is attached to the housing 60. The drive device 165 includes an actuator such as a motor or a piezo element. A drive device (not shown) that drives the deflection prism 56 and the deflection prism is attached to the housing 60.

At the next step 505, as shown in FIG. 12A, the drive controller 165 is connected to the measurement controller 63.
After connecting, laser light is emitted from the semiconductor laser unit 51. As a result, the laser light flux is received by the detection light receiving element 62, and the signals Sa and Sb from the detection optical element 62 are output to the measurement control device 63. Then, in the measurement control device 63, the difference signal ΔS _Z = (Sa−S
b) is obtained by the above-mentioned operational amplifier, and the position of the reflection mirror 53 is adjusted via the drive unit 165 based on the difference signal so that the optical axis shift is corrected. This will be described in more detail. In advance, the correlation between the difference signal ΔS _Z between the output signals Sa and Sb and the deviation amount in the emission direction in the X-axis direction (for example, the optical axis deviation amount in the Z-axis direction after the reflecting mirror 53) ( 13A), the information on the correlation is stored in the memory inside the measurement control device 63. Therefore, in the measurement control device 63, the deviation of the emission direction (the driving amount of the reflection mirror 53) is calculated based on the difference signal ΔS _Z and the correlation.
Can be accurately determined. Therefore, the reflecting mirror 53 is driven through the driving device 165 according to the calculated driving amount, and the optical axis shift is corrected. For example, in FIG.
As shown in (A), the emission optical axis from the semiconductor laser unit 51 is shifted to the + X side, and the detection light receiving element 62 is detected.
In the case where the optical axis is shifted from the ideal optical axis in the −Z direction, the measurement control device 63 causes the reflecting mirror 53 via the drive device 165 in accordance with the difference signal ΔS _Z at that time.
Is driven by a predetermined amount in the direction of arrow L, and as shown in FIG. 12B, the optical axis shift in the Z-axis direction on the rear side of the reflecting mirror 53 is automatically corrected. The reflection mirror 5
The driving direction of 3 may be the X-axis direction or the Z-axis direction.

At this time, the difference signal approaches the reference level on the screen of the monitor 64 according to the change in the position of the reflecting mirror 53. Therefore, in step 507, it is confirmed on the screen of the monitor 64 that the difference signal substantially matches the reference level, thereby confirming that the optical axis deviation correction is completed.

After that, in steps 509 and 511, the same processing as the above-mentioned steps 409 and 411 is performed. However, in step 509, when the detection light receiving element 62 is removed from the optical path, the connection between the drive device 165 and the measurement control device 63 is released at the same time.

In the next step 513, the deflecting prism 5
After the measurement control device 63 is connected to the driving device of No. 6, laser light is emitted from the semiconductor laser unit 51. As a result, the laser light flux is received by the detection light receiving element 62, and the signals Sa and Sb from the detection optical element 62 are output to the measurement control device 63. Then, the measurement control device 6
3, the difference signal ΔS _X = (Sa−Sb) is obtained by the above-mentioned operational amplifier, and the optical axis deviation (X-axis direction) after the deflection prism 56 is corrected based on the difference signal.
The position of the deflection prism 56 is adjusted via the driving device.
In this case as well, the difference signal Δ shown in FIG.
The correlation between S _X and the shift amount of the optical axis after the deflection prism 56 in the X-axis direction is obtained in advance, and the drive amount of the deflection prism 56 is determined based on this correlation and the difference signal.

Then, in step 515, the monitor 64
By confirming that the difference signal substantially matches the reference level on the screen, it is confirmed that the above optical axis deviation correction is completed.

Thereafter, in steps 517 and 519, the same processes as those in steps 417 and 419 described above are performed, so that the optical pickup device 23 is manufactured. However, in step 517, the detection light receiving element 6
When removing 2 from the optical path, at the same time, the connection between the drive device 165 (not shown) and the measurement control device 63 is released.

As described above, according to the method of manufacturing the optical pickup device of the second embodiment, the same effects as those of the first embodiment described above can be obtained, and the semiconductor laser unit 51 emits light. It is possible to automatically and accurately correct the optical axis shift due to the direction shift.

Also in the case of the second embodiment, instead of the detection light receiving element 62, the above-mentioned four-divided light receiving element 62 'is used.
May be used. In this case, the detection light receiving element 6 is placed at an arbitrary position in the optical path of the optical pickup device 23.
2'can be arranged, and correction of the optical axis shift in the two-dimensional direction can be performed at the same time. Also in this case, the above-mentioned FIG.
3 (A), based on the correlation shown in FIG. 13 (B),
The optical axis shift will be corrected.

In the first and second embodiments, the detection optical element 62 is positioned at a predetermined position through the U-shaped slide guide formed on the housing. The invention is not limited to this, and the detection optical element 62 may be positioned at a predetermined position by using an appropriate positioning jig.

In the first and second embodiments, the case where the detection light receiving element 62 is already removed at the time when the manufacturing of the optical pickup device 23 is finished has been described. The light receiving element 62 for use may be built in the housing of the optical pickup device 23 and used. From this point of view,
It is a third embodiment to be described next.

<< Third Embodiment >> Next, a third embodiment of the present invention will be described with reference to FIGS. 14 (A) and 14 (B).

In the third embodiment, the configuration of the optical pickup device 23 in the first and second embodiments is partially modified, and the other parts are the same as those in the second embodiment.
It is similar to the embodiment. Therefore, in order to avoid redundant description, the same reference numerals will be used for the same or equivalent components as in the first embodiment, and the description will be simplified or omitted. Below, it demonstrates centering around difference with 1st, 2nd embodiment.

In the optical pickup device 23 'according to the third embodiment, as shown in FIG. 14A, the beam shaping prism 69 is arranged on the optical path between the reflection mirror 53 and the polarization beam splitter 54. Is characterized in that a part of the light flux is reflected on the surface (incident surface side) thereof, and the detection light receiving element 62 ′ composed of the four-division light receiving element shown in FIG. 10 is arranged on the reflected light path. Have.

The optical elements of the optical pickup device 23 'according to the third embodiment are arranged three-dimensionally in the same manner as the optical pickup device 23 shown in FIG. However, in FIG. 14A, for convenience of illustration and description, it is shown two-dimensionally. The same applies to the subsequent drawings (FIGS. 14B to 17).

Here, a method of manufacturing the optical pickup device 23 'configured as described above will be described. First,
As shown in FIG. 14B, the semiconductor laser unit 51 and the collimator lens 5 are provided at predetermined positions in the housing 60.
2, the reflection mirror 53, the beam shaping prism 69, and the detection light receiving element 62 'are assembled.

After the assembly is completed, the semiconductor laser unit 51 emits a laser beam, so that the laser beam partially reflected on the surface of the beam shaping prism 69 is received by the detection light receiving element 62 '. After this, similarly to the first embodiment described above, based on the display on the monitor screen displayed by the measurement control device (not shown) connected to the detection light receiving element 62 ′, the adjustment mechanism (not shown) is used. Then, the positions of the reflection mirror 53 and the deflection prism 59 may be adjusted, and like the second embodiment, the detection light-receiving element 6 may be used.
The positions of the reflecting mirror 53 and the deflecting prism 56 may be automatically adjusted via a driving device based on the light receiving result of 2 '.

In this way, the optical pickup device 2
When the correction of the optical axis shift of 3'is completed, the remaining optical elements which have not been assembled up to now are assembled in a predetermined position in the housing 60, and the like. The production ends.

Also according to the manufacturing method of the third embodiment, the reference direction (ideal optical axis direction) of the emission direction of the light beam emitted from the semiconductor laser unit 51 in the initial stage of the assembling process of the optical pickup device 23 '. Since the deviation of the optical axis of the light beam due to the deviation from is corrected, it is possible to obtain the same effect as that of the first and second embodiments described above.
In addition to this, in the optical pickup device 23 ′ according to the third embodiment, unlike the first and second embodiments, the detection light receiving element 62 ′ is still built in the housing 60. The detection light receiving element 62 ′ can be used for various purposes.

For example, the sum signal (Sa +) of the output signals from the four divided areas 62a to 62d of the detection optical element 62 '.
An operational amplifier circuit for obtaining (Sb + Sc + Sd) may be incorporated in the reproduction signal processing circuit 28, and the sum signal may be sent to the laser control circuit 24 as a light quantity monitor signal of laser light. That is, the detection optical element 62 'can have a function as a front monitor light receiver.

Further, for example, similarly to the above, two kinds of difference signals {(Sa +
Sb)-(Sc + Sd)}, {(Sa + Sc)-(Sb
+ Sd)}, the positions of the reflecting mirror 53 and the deflecting prism 56 may be automatically adjusted (feedback control) via a driving device as in the second embodiment. In this case, even if the optical axis shifts over time due to vibration, heat, and other factors, the optical axis shift can always be corrected.

Further, in the optical pickup device 23 'according to the third embodiment, since the optical axis deviation between the emission optical axis and the ideal optical axis is corrected at the manufacturing stage, it is irradiated onto the recording surface of the optical disc. It is possible to reduce the deviation of the optical axis of the luminous flux as much as possible, and to suppress the occurrence of wavefront aberration and the reduction of power as much as possible.

Further, by incorporating the optical pickup device 23 'according to the third embodiment into the optical disc device 20 of FIG. 1, information can be recorded at a high density like a DVD as in the first embodiment. The information on the existing optical disc can be reproduced with high accuracy, and high-speed recording operation (writing operation) is possible.

<< Fourth Embodiment >> Next, a fourth embodiment of the present invention will be described with reference to FIG. The fourth embodiment is a partial modification of the configuration of the optical pickup device 23 in the first and second embodiments. In order to avoid repeated description, the same reference numerals will be used for the same or equivalent components as in the above embodiments, and the description will be simplified or omitted. Below, it demonstrates centering around difference with each said embodiment.

The optical pickup device 123 according to the fourth embodiment employs, as the polarization beam splitter, a deflection beam splitter 54 'having a −X side surface inclined as shown in FIG. A characteristic is that a part of the return light from the objective lens 57 side is reflected on the surface, and the detection light receiving element 62 ′ is arranged on the reflected light path.

In the optical pickup device 123 according to the fourth embodiment, since the optical axis shift can be corrected by using a part of the light flux reflected on the surface of the polarization beam splitter 54 ', the above-mentioned first embodiment is used. The optical pickup device 123 can be manufactured by substantially the same procedure as that of the third embodiment. However, in this case, since the return light is used, it is necessary to dispose the mirror M and other reflecting members near the focal plane of the objective lens 57 at the time of assembling. Excluding this point, the fourth embodiment has the following advantages.

That is, the detection light receiving element 62 'is provided on the optical path.
It is possible to manufacture an optical pickup device in which the optical axis misalignment is corrected simply by adding a detection optical element to the originally necessary component without arranging a new component for guiding the laser beam up to . Therefore, the cost increase can be suppressed, and the assembling time can be shortened, so that the productivity of the optical pickup device 123 and the optical disc device 20 can be improved. The optical pickup device 123 and the optical disc device using the same have the same effects as those of the above-described embodiments. Further, the detection optical element 62 ′ is
Since it can be left in the housing 60 as it is, it can be used for a light amount monitor or for correction of the optical axis shift over time, as in the third embodiment described above.

In the fourth embodiment, the surface of the polarization beam splitter 54 'is inclined with respect to the plane perpendicular to the optical axis. A transmission type polarization diffraction element may be provided. << Other Embodiments >>

Besides, as the optical pickup device, it is also possible to adopt a configuration as shown in FIGS. 16 (A) and 16 (B).

The optical pickup device 23 ″ shown in FIG. 16A detects return light and emits light caused by deviation of the emission direction from the semiconductor laser unit 51, as in the fourth embodiment. The optical pickup device 23 ″ allows almost all the light flux from the semiconductor laser unit 51 side to be transmitted to the optical path rearward (−X direction) of the polarization beam splitter 54 in the optical pickup device 23 ″.
A deflecting element 73 that reflects a part of the return light from the fifth side and transmits most of the returning light is arranged, and a detecting light receiving element 62 ′ composed of a four-divided light receiving element is provided on the optical path reflected by the deflecting element 73.
Are placed.

In the case of manufacturing this optical pickup device 23 ", first, as shown in FIG.
The semiconductor laser unit 51, the collimator lens 52, the reflection mirror 53, the deflection element 73, and the detection light receiving element 62 ′ are assembled at a predetermined position within 0. Then, the mirror M is arranged at a predetermined position where the optical disc is arranged, and the laser light is emitted from the semiconductor laser unit 51, so that the emission direction deviation of the laser light emitted from the semiconductor laser unit 51 is the same as before. The optical axis shift caused by is detected. Then, based on this detection result, the reflection mirror 53
The semiconductor laser unit 51 is operated by manually or automatically driving at least one of
Even if there is a deviation in the emission direction of the laser light emitted from the
(B) is indicated by a dotted line)) and the ideal optical axis LR
(Indicated by an alternate long and short dash line in FIG. 16B).

As described above, when the correction of the optical axis shift is completed, the remaining optical elements are assembled at the predetermined positions in the housing 60, and the manufacturing of the optical pickup device 23 ″ is completed.

In this case also, since the detection light receiving element 62 'is built in the inside of the housing 60, the above-described third and fourth elements are used.
It is possible to obtain the same effect as that of the above embodiment.

The above optical pickup devices 23 'and 2'
In 3 ″ or the like, the detection light receiving element 62 ′ and the beam shaping prism 69 (or the deflection element 73) may be removed after the optical axis adjustment.

Furthermore, the first light receiving element 59 can also be used as the detection light receiving element without newly providing the detection light receiving element 62 or 62 '.

That is, as shown in FIG. 17, for example, in the manufacturing process of the above-mentioned optical pickup device 23,
Main optical elements such as the laser unit 51, the collimator lens 52, the reflection mirror 53, the polarization beam splitter 54, the λ / 4 plate 55, the deflection prism 56, and the objective lens 57, and the first light receiving element 59 (tracking by the push-full method). A mirror M is arranged at a position where the optical disk 15 is positioned in a state where a light receiving element for detecting a servo signal or other servo signals or information signals is incorporated. As a result, as shown in FIG.
When the optical axis of the laser beam emitted from the laser beam 1 is deviated from the ideal optical axis, the deviation can be detected based on the output of the first light receiving element 59. By displaying and driving at least one of the reflecting mirror 53 and the deflecting prism 56 based on the displayed contents, it is possible to correct the optical axis shift after the reflecting mirror 53. After that, the remaining optical elements are attached to the housing.

In such a case, since the optical pickup device in which the optical axis shift is corrected can be manufactured with only the originally necessary parts, it is possible to suppress the cost increase and shorten the assembling time. Therefore, it is possible to improve the productivity of the optical pickup device and thus the optical disc device.

Of course, in each of the above-described embodiments, the first light receiving element 59 is used as the detection light receiving element to correct the optical axis shift, and then the light receiving element 59 is removed from the measurement control device 63 to obtain the original light receiving element 59. It may be arranged again at the light receiving position.

Note that in each of the second and subsequent embodiments described above, similarly to the above, a condensing means such as a condensing lens may be arranged close to the light receiving surface of the detection light receiving element. .

In each of the above embodiments, the reflecting mirror 5
Although the optical axis shift is corrected by driving (moving in a predetermined direction) at least one of the optical axis 3 and the deflection prism 56, for example, a parallel plate is arranged on the optical path and the parallel plate is inclined with respect to the optical axis. The optical axis shift may be corrected by adjusting the. In short, it suffices to correct the optical axis shift by driving at least one optical element arranged on the optical path of the laser light.

Further, in each of the above embodiments, a light receiving element such as a two-divided light receiving element or a four-divided light receiving element is used to detect the optical axis shift of the laser light beam, that is, the emitting direction. This is intended to detect the emitting direction at a low cost. However, the present invention is not limited to this, and instead of the light receiving element of each of the above embodiments, a PSD, a CCD camera, or the like is used,
The emission direction of the laser light may be detected in the manufacturing process of the optical pickup device.

In each of the above embodiments, the case where the semiconductor laser unit 51 emits a light flux having a single wavelength has been described. However, the present invention is not limited to this, and the semiconductor laser unit 51 is not limited to this.
When a plurality of light beams having different wavelengths are selectively emitted (when a plurality of light source units are provided), for example, so-called 1C
Even when an an2LD type semiconductor laser unit is used, the method of manufacturing an optical pickup device according to the present invention can be preferably used. That is, the optical axis deviation is detected for each wavelength when the optical pickup device is manufactured by the same procedure as that of each of the above embodiments. Then, the emission direction of the light flux of each wavelength is a predetermined angle or more (the optical axis is a predetermined distance or more)
If they are different, it is impossible to adjust the optical axis deviation, so if the semiconductor laser unit is replaced and the assembly processing is restarted from the detection of the optical axis deviation again before performing the subsequent processing. good. In such a case, when the adjustment of the optical axis deviation cannot be adjusted, the subsequent processing can be stopped at the time of recognizing it. Therefore, after the assembly is completed (after the optical pickup device is manufactured), the plurality of light source units are It has been found that it is difficult to correct the deviation of the emission direction of the light flux, and the wasteful work such as disassembling and reassembling after the disassembly can be avoided. This makes it possible to improve manufacturing efficiency. Of course, if the optical axis shift can be adjusted, the optical pickup device can be manufactured and the same effect can be obtained by the same procedure as in the above-described embodiments.

The configuration of the optical system described in each of the above embodiments is an example, and it goes without saying that the present invention is not limited to these. The optical system may be any optical system that guides the light beam emitted from the light source unit to the recording surface of the optical recording medium and guides the return light beam reflected by the recording surface to a predetermined light receiving position.

Further, when manufacturing the optical pickup device in each of the above embodiments, the position on the optical path in which the detection light receiving element is inserted is an example, and the present invention is not limited to this. The order of each process in the manufacturing process is not limited to the order of the above embodiment. That is, for example, when the semiconductor laser unit is assembled to the housing, the detection light receiving element (second light receiving element) is arranged on the optical path as described above, the emission direction (optical axis deviation) is detected, and the deviation is detected. Remember the amount, and then assemble each optical element that composes the optical system into the housing. At that time, adjust the position of the specific optical element for adjusting the optical axis deviation according to the above deviation amount ( It is also possible to adjust the optical axis shift by driving). The point is that the light source unit emits a light beam and the emission direction of the light beam is detected at any point until the process of the assembling process is completed.

[0116]

As described above, according to the method of manufacturing the optical pickup device of the present invention, it is possible to surely correct the optical axis deviation without using a holder having a complicated structure. .

Further, according to the pickup device of the present invention, the deviation of the optical axis of the light beam applied to the recording surface of the optical recording medium can be reduced as much as possible, and the occurrence of wavefront aberration and the reduction of power can be suppressed as much as possible. There is an effect.

Further, according to the optical disk device of the present invention, there is an effect that the information recorded on the optical recording medium with a high density can be reproduced with high accuracy.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of an optical disc device 20 according to a first embodiment.

FIG. 2 is a perspective view showing a configuration of an optical pickup device.

FIG. 3 is a diagram showing a configuration of a semiconductor laser unit.

FIG. 4 is a flowchart showing a procedure of manufacturing the optical pickup device according to the first embodiment.

5 (A) is a view showing a state of step 401 in FIG. 4, and FIG. 5 (B) is a perspective view showing a slide guide of FIG. 5 (A).

6A to 6D are views for explaining a method of correcting an optical axis shift using a reflection mirror.

FIG. 7 is a perspective view for explaining the arrangement position and arrangement state of the detection light receiving element in step 411 of FIG.

8A to 8D are diagrams for explaining a method of correcting an optical axis shift using a deflection prism.

FIG. 9 is a plan view showing a four-division light receiving element according to a modification.

FIG. 10 (A) is a diagram showing a state in which a condenser lens is arranged close to the light receiving surface of the detection light receiving element,
FIG. 10B is a diagram for explaining the effect when the condenser lens is arranged close to the light receiving surface of the light receiving element.

FIG. 11 is a flowchart showing a procedure of manufacturing the optical pickup device according to the second embodiment.

12A and 12B are diagrams for explaining a method of correcting an optical axis shift of the optical pickup device according to the second embodiment.

13A and 13B are diagrams showing the correlation between the difference signal and the deviation amount in the emission direction.

14A and 14B are views for explaining the configuration and the manufacturing method of the optical pickup device according to the third embodiment.

FIG. 15 is a diagram for explaining the configuration and the manufacturing method of the optical pickup device according to the fourth embodiment.

16 (A) and 16 (B) are diagrams for explaining a configuration and a manufacturing method of an optical pickup device according to another embodiment.

FIG. 17 is a diagram for explaining a configuration and a manufacturing method of an optical pickup device according to another embodiment.

[Explanation of symbols]

15 ... Optical disc (optical recording medium), 23, 23 ', 2
3 ", 123 ... Optical pickup device, 24 ... Laser control circuit (part of processing device), 25 ... Encoder (part of processing device), 28 ... Reproduction signal processing circuit (one of processing device) Part), 40 ... CPU (a part of the processing device),
51 ... Semiconductor laser unit (light source unit), 53 ...
Reflecting mirror (specific optical element), 56 ... Polarizing prism (specific optical element), 59 ... First light receiving element, 62, 62 '...
Detecting light receiving element (second light receiving element), 71 ... Condensing lens (condensing means), 165 ... Driving device.

Claims (8)

[Claims] 1. Recording and reproduction of information on an optical recording medium,
And a method of manufacturing an optical pickup device for manufacturing an optical pickup device used for reproducing at least one of erasing, comprising: guiding a light source unit and a light beam emitted from the light source unit to a recording surface of the optical recording medium. At the same time, an assembling step of assembling each optical element that constitutes the optical system that guides the return light beam reflected by the recording surface to a predetermined light receiving position in a predetermined positional relationship, and disposing the first light receiving element at the light receiving position. And a detection step of emitting a light beam from the light source unit and detecting the emission direction of the light beam at any point until the processing of the assembly step is completed; and the detection step during the processing of the assembly step. Driving at least one specific optical element constituting the optical system based on the emitted direction, and causing the deviation of the emitting direction from the reference direction. And a step of correcting the optical axis shift of the light flux. 2. The optical pickup device according to claim 1, wherein in the detecting step, the emission direction of the light beam is detected by using a second light receiving element having a light receiving surface divided into at least two. Production method. 3. The method according to claim 2, further comprising the step of disposing a condensing means for condensing a light beam incident on the light receiving surface in the vicinity of the light receiving surface of the second light receiving element. A method of manufacturing the optical pickup device according to item 1. 4. The second light receiving element is the same light receiving element as the first light receiving element.
Alternatively, the method of manufacturing the optical pickup device according to the item 3 above. 5. The light according to claim 1, wherein in the correction step, a drive device that drives the specific optical element based on the detected deviation in the emission direction is used. Manufacturing method of pickup device. 6. In the detecting step, the emission directions are respectively detected for a plurality of light fluxes having different wavelengths, and when the emission directions of the plurality of light fluxes are different from each other by a predetermined angle or more, the process of the assembling step is performed. The method for manufacturing an optical pickup device according to claim 1, further comprising a step of replacing the light source unit on the way. 7. An optical pickup device manufactured by the method for manufacturing an optical pickup device according to claim 1. 8. An optical disc device for recording, reproducing, and erasing information on and from an optical disc, the optical pickup device according to claim 7, and the optical pickup device according to claim 7. An optical disc device comprising: a processing device for performing at least reproduction of the information recording, reproduction, and erasing using the output signal of the first light receiving element.