JPH1031832A - Optical pickup device - Google Patents

Abstract

(57) [PROBLEMS] An optical pickup device capable of positioning a laser light emitting element and a light receiving element for signal detection with high accuracy, assembling without performing complicated fine adjustment, and improving the assembling workability. Is to provide. A laser diode for irradiating the irradiation target with laser light; a photodiode for receiving the laser light reflected from the irradiation target and performing photoelectric conversion;
In the optical pickup device including the laser diode 17 and the base 11 on which the photodiode 19 is mounted, the base 11 is formed of a light-transmitting material, and the base 11 is provided with the laser diode 17.
Outgoing surface 17a, light receiving surface 19a of photodiode 19
At least one of the laser diodes 17
Outgoing surface 17a and light receiving surface 19a of photodiode 19
Are positioned at the same plane position.

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 for reading, for example, a signal from an optical disk and a method for manufacturing the same.

[0002]

2. Description of the Related Art An optical pickup device for reading a signal from an optical disk comprises a laser diode as a laser light emitting element, a hologram optical element and a photodiode as a light receiving element for signal detection. Then, the laser light emitted from the laser diode passes through the hologram optical element, forms an image on the optical disk by the imaging lens, and the reflected light returns along the same optical path and enters the hologram optical element again. I have. The laser light split and deflected by the hologram optical element is incident on the light receiving surface of the photodiode.

Here, the photodiode is an element divided into a plurality of parts, and controls tracking and focusing of the optical pickup device. In recent years, the track pitch has become smaller as the recording density of optical discs has increased, and the depth of focus of imaging lenses has become smaller. I have. That is, in assembling the optical pickup device, a high positional accuracy of the photodiode with respect to the laser diode is required.

FIGS. 11 and 12 show a part of a conventional optical pickup device, wherein 1 is a base such as a metal block. The base 1 has a horizontal plane 1a and a vertical plane 1 orthogonal to each other.
b. A photodiode 2 is mounted on a horizontal surface 1a of the base 1, and a laser diode 3 is mounted on a vertical surface 1b via a submount 4. The photodiode 2 is an element divided into a plurality of parts, the light receiving surface 2a thereof faces a hologram optical element (not shown), and the light emitting point 3a of the laser diode 3 faces the hologram optical element.

In assembling the optical pickup device, first, a submount 4 on which a laser diode 3 is mounted is fixed to a vertical surface 1b of a base 1 with a light-curing or thermosetting adhesive or the like. The photodiode 2 is fixed to the horizontal surface 1a of the base 1. At this time, the light-receiving surface 2a of the photodiode 2 is fixed at a certain distance with respect to the light emitting point 3a of the laser diode 3 in the XYZ directions. Accuracy of 5 μm is required.

[0006]

As described above, in the conventional optical pickup device, when the laser diode 3 and the photodiode 2 are fixed to the base 1, the vertical surface 1b of the base 1 faces upward, The radar diode 3 is fixed on the vertical surface 1b, and then the base 1 is inverted so that the horizontal surface 1a faces upward, and the photodiode 2 is fixed on the horizontal surface 1a. At this time, the light receiving point of the photodiode 2 is positioned with reference to the light emitting point of the laser diode 3, and the light emitting surface 3b of the laser diode 3 and the light receiving surface 2a of the photodiode 2 are adjusted so as to be on the same plane. Both need to be fixed to the base 1. At this time, as described above, since an accuracy of ± 5 μm is required in the XYZ directions, the fine adjustment and the assembling work require many man-hours, resulting in an increase in cost.

The present invention has been made in view of the above circumstances, and an object thereof is to achieve high-precision positioning only by bringing a laser light emitting element and a signal detecting light receiving element into contact with a base. An object of the present invention is to provide an optical pickup device which can be assembled without performing complicated fine adjustment and a method of manufacturing the same.

[0008]

In order to achieve the above object, the present invention provides a laser light emitting element for irradiating a laser beam to an object to be irradiated, and a laser light emitting element for reflecting the laser beam reflected from the object to be irradiated. An optical pickup device comprising: a signal detection light receiving element for receiving light and performing photoelectric conversion; and a base on which the laser light emitting element and the signal detection light receiving element are mounted, wherein the base has a light-transmitting material. The laser light emitting element is brought into contact with the base, and the position of the light emitting surface of the laser light emitting element and the position of the light receiving surface of the signal detecting light receiving element are positioned at the same plane position. .

According to a second aspect of the present invention, the base of the first aspect has a contact surface for contacting a light receiving surface of the signal detecting light receiving element and a contact surface for contacting a surface other than the emission surface of the laser light emitting element. The position of the light emitting surface of the laser light emitting element and the position of the light receiving surface of the signal detecting light receiving element are positioned at the same plane position.

According to a third aspect of the present invention, there is provided the base according to the second aspect, wherein the contact surface for abutting the light receiving surface of the signal detecting light receiving element has a positioning groove for positioning the signal detecting light receiving element. Features.

A fourth aspect of the present invention is characterized in that the base surface of the second aspect has a positioning groove for positioning the laser light emitting element on a contact surface with which the laser light emitting element abuts. 6. A laser light emitting element for irradiating a laser beam to an irradiation target, a signal detection light receiving element for receiving the laser light reflected from the irradiation target and performing photoelectric conversion, the laser light emitting element and the signal. In an optical pickup device including a base on which a light receiving element for detection is mounted, the base is formed of a light-transmitting material, and an emission surface of the laser light emitting element is brought into contact with the base. An abutting surface, an abutting surface formed to intersect the abutting surface, the abutting surface being in contact with the light receiving surface of the signal detecting light receiving element, and the abutting surface being in contact with the emission surface of the laser light emitting element. A reflecting surface that reflects the laser light emitted from the device in a direction in which the laser light travels toward the irradiation target.

According to a sixth aspect of the present invention, the laser light emitting element and the signal detecting light receiving element of the fifth aspect are respectively fixed to a single mounting member, and the light emitting surface of the laser light emitting element and the light receiving surface of the signal detecting light receiving element are fixed. It is characterized by being positioned by contacting each contact surface of the base.

According to a seventh aspect of the present invention, a contact groove for abutting the light receiving surface of the signal detecting light receiving element of the base has a positioning groove for positioning the signal detecting light receiving element. Features.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment, in which 11 is a base, and this base 11 is made of a light-transmitting material, for example, glass or plastic having good heat conductivity such as quartz or sapphire. Although formed, quartz having excellent light transmittance is desirable. The base 11 is integrally provided with a protruding portion 12 protruding downward.

A first contact surface 13 having a horizontal surface 13a and a vertical surface 13b is provided on the lower surface at one end of the base 11 with the protrusion 12 as a boundary, and the lower surface at the other end is perpendicular to the horizontal surface 14a. A second contact surface 14 having a surface 14b is provided. Further, an inclined surface 15 is formed above the base 11 on the first contact surface 13 side to form a clearance so as not to hinder the irradiation of the laser beam.

The angle between the horizontal plane 13a and the vertical plane 13b of the first contact surface 13 is a right angle, and the submount 16 is formed of a rectangular metal block so as to make surface contact with both surfaces.
The submount 16 is fixed to the base 11 with a light-curing or thermosetting adhesive or the like. Further, a laser diode 17 as a laser light emitting element is mounted on the submount 16 by soldering, using an adhesive having good heat conductivity, or the like, and an emission surface 17 a of the laser diode 17 is formed on the second contact surface 14. It is positioned on the Z-direction reference plane 18 on the same plane as the horizontal plane 14a.

The angle between the horizontal surface 14a and the vertical surface 14b of the second contact surface 14 is a right angle, and the photodiode 1 as a signal detecting light receiving element is brought into surface contact with both surfaces.
9 has its light receiving surface 19a in contact with the horizontal surface 14a, and the photodiode 19 is fixed to the base 11 with a light-curing or thermosetting adhesive or the like. The light receiving surface 19a of the photodiode 19 is positioned on the Z-direction reference surface 18 on the same plane as the horizontal surface 14a of the second contact surface 14.

Accordingly, the submount 16 is brought into contact with the first contact surface 13 and the photodiode 19 is brought into contact with the second contact surface 14, so that the emission surface 17 a of the laser diode 17 and the light received by the photodiode 19 are received. The surface 19 a is positioned on the same plane with respect to the Z-direction reference surface 18.

According to the optical pickup device configured as described above, as shown in FIG. 3, after the laser beam L emitted from the laser diode 17 passes through the hologram optical element 20, the optical disk (not shown) is formed by the imaging lens. ), The reflected light returns on the same optical path, and is again incident on the hologram optical element 20, and the hologram optical element 20
The laser beam L split and deflected by the laser beam passes through the light-transmitting base 11 and passes through the light-receiving surface 19 a of the photodiode 19.
To be incident on.

FIGS. 4 and 5 show a second embodiment.
The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the present embodiment, the horizontal plane 13a of the first contact surface 13 and the horizontal plane 1 of the second contact surface 14
4a are provided with positioning grooves 21 and 22 along the Y direction. These positioning grooves 21 and 22 are substantially U-shaped grooves opened on the end face of the base 11, and the laser diode 17 and the photodiode 19 are slid by sliding the submount 16 and the photodiode 19 in the Y direction from the end face of the base 11. 19 are positioned with high precision in the X and Z directions.

That is, the radar diode 17 is mounted on the submount 16, and the submount 16 is positioned in the positioning groove 21 and slid, whereby X
The position in the direction is regulated. Also, the photodiode 19
Is positioned in the positioning groove 22 and slid, whereby the position in the X direction is regulated. Therefore, since the light emitting point of the laser diode 17 and the light receiving point of the photodiode 19 are positioned, fine adjustment at the time of assembly can be simplified, and assembling workability can be improved.

FIG. 6 shows a third embodiment. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. Reference numeral 24 denotes a base. The base 24 is made of a light-transmitting material, for example, optical glass having good heat conductivity such as quartz or sapphire. At one end of the base 24, a projection 25 protruding downward is provided.

A contact surface 26 having a horizontal surface 24a and a vertical surface 24b is provided on a lower surface of the base 24, and a protrusion 25
Is provided with an inclined surface 27 having an inclination angle θ of 45 °, and the inclined surface 27 is provided with a reflecting surface 28 by coating by vapor deposition or the like.

On the other hand, reference numeral 29 denotes a submount base as a mounting member made of a metal plate having excellent heat conductivity. On the upper surface 29a of the submount base 29, the photodiode 19 has its light receiving surface 19a facing upward (horizontal plane 24a).
Side) and fixed. The laser diode 17 has an emission surface 17a at the end of the lower surface 29b of the submount base 29 via a submount 30, and the vertical surface 24.
b.

The submount base 29 on which the photodiode 19 and the laser diode 17 are mounted
Sets the light receiving surface 19a of the photodiode 19 to a horizontal plane 24.
a, and is fixed to the base 24 in a state where the emission surface 17a of the laser diode 17 is in contact with the vertical surface 24b.

According to the optical pickup device configured as described above, the laser light L emitted from the laser diode 17 passes through the projection 25 of the base 24, goes to the inclined surface 27, and is reflected by the reflection surface 28. You. The laser light L reflected by the reflection surface 28 passes through the base 24 and passes through a hologram optical element (not shown), and then forms an image on an optical disk (not shown) by an imaging lens. Then, the laser light L is again incident on the hologram optical element, and is split and deflected by the hologram optical element, passes through the base 24, and is incident on the light receiving surface 19a of the photodiode 19.

FIG. 7 shows a modification of the third embodiment, in which a positioning groove 26a is provided in a horizontal plane 24a of a contact surface 26 of a base 24 along the Y direction. The positioning groove 26a is a substantially U-shaped groove that opens on the end face of the base 24. The laser diode 17 and the photodiode are slid from the end face of the base 24 in the Y direction along the positioning groove 26a. Reference numeral 19 is positioned in the X direction (perpendicular to the plane of FIG. 7), and the Y direction is positioned by bringing the emission surface 17a of the laser diode 17 into contact with the vertical surface 24b.

FIG. 8 shows a fourth embodiment, in which the same components as those of the third embodiment are denoted by the same reference numerals and description thereof is omitted. On the other hand, reference numeral 31 denotes a submount base as a mounting member made of a metal block having excellent thermal conductivity. On the upper surface 31a of the submount base 31, the photodiode 19 has its light receiving surface 19a facing upward (horizontal plane of the base 24). 24a). The laser diode 17 is fixed to an end of the lower surface 31 b of the submount base 31 with its emission surface 17 a facing the vertical surface 24 b of the base 24.

The submount base 31 on which the photodiode 19 and the laser diode 17 are mounted
Sets the light receiving surface 19a of the photodiode 19 to a horizontal plane 24.
The laser diode 17 is fixed to the base 24 in a state where the emission surface 17a of the laser diode 17 abuts against the vertical surface 24b.

According to the optical pickup device configured as described above, the laser light L emitted from the laser diode 17 passes through the projection 25 of the base 24, goes to the inclined surface 27, and is reflected by the reflecting surface 28. You. The laser light L reflected by the reflection surface 28 passes through the base 24 and passes through a hologram optical element (not shown), and then forms an image on an optical disk (not shown) by an imaging lens. Then, the laser light L is again incident on the hologram optical element, and is split and deflected by the hologram optical element, passes through the base 24, and is incident on the light receiving surface 19a of the photodiode 19.

FIG. 9 shows a modification of the fourth embodiment, in which a positioning groove 26a is provided in a horizontal plane 24a on a contact surface 26 of a base 24 along the Y direction. The positioning groove 26a is a substantially U-shaped groove that opens on the end face of the base 24. The laser diode 17 and the photodiode are slid from the end face of the base 24 in the Y direction along the positioning groove 26a. Reference numeral 19 is positioned in the X direction (perpendicular to the plane of FIG. 9), and the Y direction is positioned by bringing the emission surface 17a of the laser diode 17 into contact with the vertical surface 24b.

FIG. 10 shows a fifth embodiment, and a method of manufacturing the optical pickup device shown in the second embodiment will be described. First, the base 11 made of a transparent material such as quartz or sapphire is fixed to the fixing jig 40. The fixing jig 40 is made of a material having excellent thermal conductivity such as Cu (copper), and the base 11 is placed on the first and second contact surfaces 13 and 14 with respect to the fixing jig 40 so that the horizontal plane is horizontal. Fix so that

Next, the submount 16 on which the laser diode 17 is mounted is gripped by a suction head (not shown) or the like, and is positioned on the end face of the positioning groove 21 formed on the horizontal surface of the first contact surface 13. Mount 16
From the end surface of the base 11 in the Y direction. And
The submount 16 contacts the vertical surface 13b.

Similarly, the photodiode 19 is gripped by a suction head (not shown) or the like, and the second contact surface 14
And the photodiode 19 is slid in the Y direction from the end surface of the base 11. And the photodiode 19
Of the photodiode 19 abuts on a horizontal plane, and the end face of the photodiode 19 abuts on a vertical plane. Then, the submount 16 and the photodiode 19 are fixed to the base 11 with a light-curing or thermosetting adhesive.

Next, the laser diode 17 and the photodiode 19 are electrically connected to a circuit board (not shown) by wire bonding or the like. In addition, a solder paste is applied between the laser diode 17 and the fixing jig 40, and a thermosetting potting agent having a heat radiation property is applied between the photodiode 19 and the base 11.

Next, the base 11 including the fixing jig 40, the laser diode 17 and the photodiode 19 are placed in a heating furnace or the like, and the components are joined and fixed by soldering and thermosetting.

As described above, since the laser diode 17 is mounted on the submount 16, the position in the X direction is regulated by positioning and sliding the submount 16 in the positioning groove 21. The position of the photodiode 19 in the X direction is regulated by sliding in the positioning groove 22 while positioning the photodiode 19. Therefore, since the light emitting point of the laser diode 17 and the light receiving point of the photodiode 19 are positioned, fine adjustment at the time of assembly can be simplified, and assembling workability can be improved.

In the fifth embodiment, the method of manufacturing the optical pickup device shown in the second embodiment has been described. However, the first embodiment, the third embodiment, and the fourth embodiment will be described.
The optical pickup device shown in the embodiment can also be manufactured by basically the same manufacturing method.

[0039]

According to the first aspect of the present invention, the base is formed of a translucent material, and the base has at least one of the emission surface of the laser light emitting element and the light receiving surface of the signal detection light receiving element. And the light emitting surface of the laser light emitting element and the light receiving surface of the signal detecting light receiving element are positioned on the same plane, so that the laser light emitting element and the signal detecting light receiving element can be positioned with high accuracy, and complicated fine adjustment can be performed. It is possible to assemble without performing, and to improve the assembling workability.

According to the second aspect, the signal detecting light-receiving element and the laser light-emitting element can be positioned only by abutting on the abutting surface, and the assembling workability can be improved. According to the third aspect, there is an effect that positioning can be performed by sliding the light detecting element for signal detection along the positioning groove.

According to the fourth aspect, the laser light emitting element can be positioned by sliding along the positioning groove. According to the fifth and sixth aspects of the present invention, the base is made of a material having a light-transmitting property, and the light emitting surface of the laser light emitting element and the light receiving surface of the signal detecting light receiving element are brought into contact with the base to position the base. By providing the surface, the laser light emitting element and the signal detecting light receiving element can be simultaneously attached to the base, and workability can be improved. According to the seventh aspect, by sliding the light detecting element for signal detection along the positioning groove, the laser light emitting element can be simultaneously positioned and fixed.

[Brief description of the drawings]

1A and 1B show an optical pickup device according to a first embodiment of the present invention, wherein FIG. 1A is a plan view, FIG. 1B is a front view, and FIG.

FIG. 2 is an enlarged front view of the optical pickup device of the embodiment.

FIG. 3 is an operation explanatory view of the optical pickup device of the embodiment.

4A and 4B show an optical pickup device according to a second embodiment of the present invention, wherein FIG. 4A is a bottom view, FIG. 4B is a left front view, and FIG.
Is a right side view, and (d) is a front view.

FIG. 5 shows the optical pickup device of the embodiment;
(A) is a front view showing an assembling procedure, and (b) is a front view of an assembled state.

FIG. 6 is a front view showing an optical pickup device according to a third embodiment of the present invention.

FIG. 7 is an exemplary front view of an optical pickup device showing a modification of the embodiment;

FIG. 8 is a front view showing an optical pickup device according to a fourth embodiment of the present invention.

FIG. 9 is an exemplary front view of an optical pickup device showing a modification of the embodiment;

FIG. 10 is a front view of an optical pickup device showing a fifth embodiment of the present invention.

11A and 11B show a conventional optical pickup device, wherein FIG. 11A is a plan view and FIG. 11B is a front view.

FIG. 12 is an enlarged front view of the conventional optical pickup device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Base 13 ... 1st contact surface 14 ... 2nd contact surface 17 ... Laser diode 17a ... Outgoing surface 19 ... Photodiode 19a ... Light receiving surface

Claims (7)

[Claims] 1. A laser light emitting element for irradiating a laser beam to an irradiation target, a signal detecting light receiving element for receiving the laser light reflected from the irradiation target and photoelectrically converting the laser light, the laser light emitting element and the signal An optical pickup device comprising: a base on which a light receiving element for detection is mounted; wherein the base is formed of a material having translucency, and an emission surface of the laser light emitting element is brought into contact with the base; An optical pickup device wherein the position of the light emitting surface of the laser light emitting element and the position of the light receiving surface of the light receiving element for signal detection are positioned at the same plane position. 2. The base has an abutment surface that abuts a light-receiving surface of the signal detection light-receiving element and an abutment surface that abuts a surface other than the emission surface of the laser light-emitting element, and the emission surface of the laser light-emitting element. 2. The optical pickup device according to claim 1, wherein a light-receiving surface of the light-receiving element for signal detection is positioned on the same plane. 3. A positioning groove for positioning the signal detecting light receiving element on a contact surface of the base where the light receiving surface of the signal detecting light receiving element abuts.
An optical pickup device as described in the above. 4. The optical pickup device according to claim 2, wherein a positioning groove for positioning the laser light emitting element is provided on a contact surface of the base that contacts the laser light emitting element. 5. A laser light emitting element for irradiating a laser beam to an irradiation target, a signal detecting light receiving element for receiving the laser light reflected from the irradiation target and performing photoelectric conversion, the laser light emitting element and the signal An optical pickup device comprising: a base on which a light receiving element for detection is mounted; wherein the base is formed of a material having translucency, and an emission surface of the laser light emitting element is brought into contact with the base. An abutting surface, an abutting surface formed to intersect the abutting surface, the abutting surface being in contact with the light receiving surface of the signal detecting light receiving element, and the abutting surface being in contact with the emission surface of the laser light emitting element An optical pickup device provided with a reflection surface that reflects a laser beam emitted from the device in a direction in which the laser beam travels toward an irradiation target. 6. A laser light emitting element and a signal detecting light receiving element are respectively fixed to a single mounting member, and an emitting surface of the laser light emitting element and a light receiving surface of the signal detecting light receiving element are each a contact surface of a base. 6. The optical pickup device according to claim 5, wherein the optical pickup device is positioned by being brought into contact with the optical pickup. 7. A positioning surface for positioning said signal detecting light receiving element on a contact surface of said base for contacting a light receiving surface of said signal detecting light receiving element.
An optical pickup device as described in the above.