JP2000294867A - Optical integrated device and optical head device using the same - Google Patents

Abstract

[PROBLEMS] To accurately and easily perform optical axis adjustment and alignment of a light emitting section in an optical integrated device and an optical head device using the same. SOLUTION: The integrated optical element 1 has a configuration in which a light emitting unit 2a and another optical element or a light receiving unit 2b are housed in a housing member. Positioning unit 10 for optical axis adjustment or alignment
Is formed on the housing member of the element 1 or its lead frame or substrate, and the positioning section 10 is provided on the optical axis of the light emitting section 2a or at a position symmetrical with respect to the optical axis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated optical device including a light emitting section and a technique for adjusting and aligning an optical axis in an optical head device using the same.

[0002]

2. Description of the Related Art In the field of an optical integrated circuit in which an optical element is miniaturized and a large number of elements are arranged on a single substrate to achieve integration, a semiconductor laser is used as a light source and packaged. Device is used.

For example, in the case of an optical head device (so-called optical pickup) used for reading information from an optical disk, a device in which only a semiconductor laser is packaged, or a device in which a semiconductor laser and a photodetector are integrated on the same substrate ( A so-called laser coupler) or the like is used, and the recorded content of the optical disk is read by detecting return light after irradiating the optical disk with a laser beam through an objective lens.

Therefore, in such an optical system (or optical path system), the accuracy of the alignment of the optical axis with the center of each optical element is a factor affecting the performance. And the optical axis of other optical components must be accurately aligned.

[0005]

By the way, in a device in which only a semiconductor laser is packaged, the outer shape (shape viewed from the optical axis direction of the laser) such as a can package or a stem base is circular, and an axis passing through the center thereof is formed. If the light emitting point (light emission center point) of the semiconductor laser is designed above, the device only needs to be positioned on the supporting member based on the outer shape (that is, since the outer shape is circular, If the positioning is accurately performed by a guide relative to the outer shape of the device, the laser emission point is inevitably located on the axis passing through the center of the circle.) Therefore, the assembly of the optical head device is relatively easy. For devices with a configuration combining optical elements other than lasers, such as couplers, miniaturization is possible if the external shape is circular. Since a disadvantage that lead to impaired occurs, not been able to locate the emission points of the laser on an axis passing through the center of the outer shape, there is the emission point of the laser comes to a position displaced from the said axis.

In such a case, since the light emitting point comes out of a symmetrical position in the device outer shape (for example, a center position in the longitudinal direction of the device), the laser based on the outer shape of the device is used as a reference. It becomes difficult to adjust the position of the light emitting point, which causes a problem in the accuracy of the mounting or a situation in which the operation takes time.

SUMMARY OF THE INVENTION It is an object of the present invention to accurately and easily perform optical axis adjustment and alignment of a light emitting unit in an optical integrated device and an optical head device using the same.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, according to the present invention, a positioning member formed on an element accommodating member or its lead frame or substrate for optical axis adjustment or alignment is provided. On the optical axis or symmetrically with respect to the optical axis.

Therefore, according to the present invention, since the positioning portion is located on the optical axis of the light emitting portion or symmetrically arranged with respect to the optical axis, it is not necessary to make the outer shape of the housing member or the like circular. In addition, if the adjustment and the positioning of the positioning section are performed accurately, the optical axis of the light emitting section is accurately determined as a result, thereby simplifying the operation.

[0010]

FIG. 1 shows the basic structure of an integrated optical device according to the present invention. In the integrated optical device 1, a light emitting section and another optical element or a light receiving section are contained in a housing member (package). It has a configuration in which

In the example shown in FIG. 1, an optical integrated device 1 is formed as a unitized unit by connecting a lens member 3 to a main body (optical integrated device unit) 2 including a light emitting unit and a light receiving unit. Being manufactured. The light emitting unit 2 in the device
a (shown by a broken line in FIG. 1) is a semiconductor laser,
A light emitting diode or the like is used, and a light receiving portion 2b (FIG. 1)
Is shown by a broken line. For example, a photodiode or a phototransistor is used.

An "LL" line shown by a one-dot chain line in the drawing indicates the optical axis of the light emitting portion 2a, for example, when the light emitting portion 2a is formed of a laser chip, the optical axis of the laser irradiation light. The point P located on the optical axis indicates the light emitting point. As can be seen from the figure, the light emitting unit 2a is the optical integrated device 1
The optical axis “L-L” does not coincide with the central axis of the main body 2 because the optical axis “LL” is provided at a position near the end, not at the central part.

Incidentally, the “optical axis of the light emitting section” includes the irradiation axis emitted from the optical integrated device 1 in addition to the optical axis in a narrow sense.

For example, in the configuration of the optical integrated device 4 shown in FIG. 2, a photodetector 6 serving as a photodetector is provided on a substrate 5.
6 '(for example, two sets of three-division photodiodes are used), and a prism portion 7 is provided thereon. A light emitting section 8 is provided on the substrate 5 at a predetermined distance from the prism section 7. Light emitted from the laser chip 9 toward the slope 7a of the prism section 7 is reflected by the slope. After folding and turning at right angles (only the reflected light is shown in the figure),
The light is emitted from the optical integrated device 4.

The return light reaches the photodetectors 6 and 6 'after refraction on the inclined surface 7a of the prism portion 7 (one of the photodetectors 6 receives the refracted light, and the other photodetector 6' further receives all the light thereafter). The reflected light is received.).

Therefore, in this example, what is important in relation to positioning with other optical components is not the optical axis of the laser chip itself, but the traveling direction of light emitted from the laser chip and reflected by the prism section 7 after being reflected. (Irradiation axis “LL” of the optical integrated device 4), and it is impossible to fulfill the purpose of the present invention unless this axis is considered to be included in the “optical axis of the light emitting unit”. it is obvious. That is, the center of the positioning unit 10 in this case is provided at a position on the irradiation axis LL on the back surface of the substrate 5 (or its support member).

The light emitting section 2 of the optical integrated device 1
a using other optical components (that is, the element 1
A positioning part 10 (see FIG. 1) is formed on the housing member of the optical integrated device 1 or its lead frame or substrate in order to perform optical axis adjustment and alignment with respect to the components constituting the optical system. The positioning section is provided on the optical axis of the light emitting section 2a or at a position symmetrical with respect to the optical axis.

The positioning section 10 has, for example, the following forms.

(I) holes and concave portions (ii) convex portions (iii) landmarks (marks and the like).

That is, the holes and the projections are formed by a method of mechanically adjusting the position of the optical system by using equipment (positioning adjustment device) such as a guide pin or a jig having the corresponding guide holes. used.

The mark is used as a target in the optical axis adjustment method using image recognition, and the mark captured by the imaging device can be used as a substitute for the light emitting point P.
In addition, this mark is a mark by printing, a black and white pattern,
It is desirable to use a material having a clear difference in light and darkness (contrast) and a difference in reflectance, such as a reflective material.

Example 1 of Integrated Optical Device shown in FIGS. 3 and 4
3A shows an example in which the positioning unit 10 is formed as one bottomed hole 10a, and the center of the positioning unit 10 is the optical axis L- of the light emitting unit.
L. That is, when the reference plane for positioning in the main body 2 is “π”, the plane π and the optical axis LL
(This is indicated by the point Q) is the center of the hole 10a when the hole 10a is viewed from a direction orthogonal to the reference plane π.

The shape of the hole for positioning may be a circle, an ellipse, a polygon, or the like. From the viewpoint of improving the accuracy in forming the hole, a shape (a circle or the like) as symmetric as possible is preferable. Further, it is preferable to form a tapered surface in the hole. That is, the hole is formed so that the cross-sectional area becomes smaller as it approaches the light-emitting portion (light-emitting point), and the cross-sectional area gradually increases as the hole becomes farther from the light-emitting portion. And).

FIG. 4 shows the relationship between the positioning portion (hole 10a) and the corresponding guide pin 11.

The guide pin 11 is provided on a jig (not shown) used at the time of optical axis adjustment. In this embodiment, the positioning pin 10a has a tapered surface and is adapted to this. Frustoconical part is formed,
By inserting this into the positioning hole 10a as the insertion portion 11a, the optical integrated device 1 can be positioned smoothly.

That is, when a two-dimensional orthogonal coordinate system XY is set on the reference plane π, and the X axis is the longitudinal direction of the main body 2 and the axis orthogonal to this is the Y axis, the guide pin 11 is The hole is moved in the direction along the optical axis LL, and is inserted into the positioning hole 10a, and the hole position in the XY plane is automatically determined when the final position is determined. become.

Therefore, the remaining adjustment is the angular coordinate θ around the optical axis of the light emitting section. In this adjustment, the positioning holes (or convex portions or marks) are used so that the rotation center of the θ axis can be easily obtained. When the center of is located on the optical axis of the light emitting section,
Positioning is facilitated, and adjustment equipment is simplified.

The positioning section 10 is not limited to a housing member, but can be provided on a lead frame, a board (including a flexible printed board), or the like.

Although FIGS. 3 and 4 show an example in which only one hole as a positioning portion is provided, the present invention is not limited to this.
The positioning part is composed of a plurality of holes or protrusions or marks,
These may be arranged with a symmetrical positional relationship around the optical axis LL of the light emitting section. This is effective when the positioning section cannot be formed directly behind the light emitting section.

FIG. 5 shows two holes (recesses) 10b on both sides of the intersection Q between the reference plane π of the main body 2 and the optical axis LL.
1B shows an example 1B of an optical integrated device in which 10b are arranged at equal distances.

That is, in this example, the positioning holes 10
b and 10b are line-symmetrical with respect to the perpendicular bisector (passing through the point Q) of the line connecting these centers.

In the example shown in FIG. 6, the intersection Q between the reference plane .pi.
1C shows an example of an optical integrated device in which three positioning projections 12, 12,... Are arranged. In this case, the center of each projection 12 is positioned at the vertex of a square (square, rhombus, or the like). The point Q is located at the intersection of the diagonal lines (that is, the center of the cross).

It should be noted that the present invention is not limited to such an example, and it is needless to say that various embodiments such as positioning the center of the positioning portion at each vertex of a triangle or a polygon having five or more angles are possible.

With respect to the optical integrated device described above,
When this is applied to an optical head device used for reproducing and recording information on an optical recording medium (optical disk, magneto-optical disk, etc.), the assembling work is simplified, and the equipment required for assembling and adjusting is simplified. There is an advantage.

That is, in an optical head device including an optical integrated type light transmitting / receiving section having a configuration in which a light emitting section and a light receiving section are housed in a housing member, an optical axis adjustment or alignment of the light emitting section in the light transmitting / receiving section is performed. And a positioning part for the light emitting and receiving part, or a lead frame or a substrate thereof, and the positioning part is provided on the optical axis of the light emitting part or at a position symmetrical with respect to the optical axis. Is preferred.

FIG. 7 shows a configuration example 13 of an optical pickup (or optical pickup) used as an optical head device for reproducing and recording information on an optical recording medium, and is shown along the left and right direction of the paper surface. A light transmitting / receiving unit 15 and a biaxial actuator 16 are attached to a slide base 14 that moves along.

That is, the biaxial actuator 16 for supporting the objective lens 16a is provided on the slide base 14.

A light transmitting / receiving unit (light transmitting / receiving unit) 15
Is composed of an integrated optical device (or integrated optical device) 15a having a light emitting unit and a light receiving unit, a lens 15b, and a prism 15c provided on the lens. 14 is housed in a recess 14 a formed by partially cutting out
The lead frame 17 of the optical integrated device 15a is
The slide base 1 is fixed to the steps 18 of the slide base 1.
4 attached. The “LL” line indicated by a one-dot chain line in the drawing indicates the optical axis, and the optical integrated device 15a
It extends above the plane of the paper through the light emission center of the light-emitting portion inside, and is turned 90 ° by a rising mirror (not shown) so as to be made an axis perpendicular to the paper through the center of the objective lens 16a.

FIG. 8 is a schematic diagram showing only the light transmitting and receiving unit 15 (light transmitting and receiving unit including the lens 15b) from the side.
Package (housing member) for housing optical integrated device 15a
19 and a lens 18 provided on the front surface thereof (the direction in which light is irradiated is defined as forward).

A lead frame 17 is provided along the longitudinal direction of the package 19, and a positioning hole 20 (shown by a broken line in the figure) is provided behind the lead frame and at the rear (rear) of the package 19. As described above, it is formed as a concave portion having a tapered surface extending rearward.)
The center of the hole 20 is located on the optical axis LL of the light emitting unit described later.

FIG. 9 shows the integrated optical device 15a when viewed from the direction along the optical axis LL with the lens 15b removed.
Is shown.

A laser diode is used for the light emitting section 21, and an axis extending perpendicular to the plane of the drawing through the light emitting point is an optical axis LL. That is, the center of the hole 20 (indicated by a broken-line circle in the figure) when viewed from the optical axis direction coincides with the light emitting point.

A photodetector 22 is disposed at a position at a certain distance from the light emitting section 21 and is used for detecting return light. In other words, the light emitted from the light emitting unit 21 passes through the lens 15b and the prism 15c in that order, and is then applied to the optical recording medium through the objective lens 16a (the light emitted from the lens 15b in FIG. The light reflected by the recording layer of the recording medium passes through the lens 15b again and is separated and reaches the photodetector 22 after passing through the objective lens 16a after a 90 ° optical path change. It is well known that a means for separating the emitted light beam and the received light beam (such as a beam splitter) is provided.

In the optical axis alignment of the light transmitting and receiving unit 15 in the above-described assembling process of the optical head device 13, the positioning hole 20 formed in the package 19 of the light transmitting and receiving unit 15 is replaced with this hole. If a guide pin (not shown) having a shape corresponding to the shape is provided on the jig, and the guide pin is moved toward the positioning hole 20 and finally inserted into the hole 20, the optical axis L Positioning in a plane perpendicular to -L (the XY plane described above) is completed.

Then, after the adjustment around the optical axis (the above-described θ adjustment) is performed and the mounting posture of the light transmitting / receiving unit 15 is determined,
What is necessary is just to fix both ends of the lead frame 17 to the abutting surfaces of the steps 18 of the slide base 14.

In the present embodiment, the positioning portion (the center of which is located on the optical axis LL of the light emitting portion 21) provided in the light transmitting / receiving portion 15 is a hole, but is not limited thereto. As described above, it may be a part or a mark, and a plurality of positioning parts may be arranged in a symmetrical positional relationship around the optical axis of the light emitting part 21.

According to the above configuration, the following advantages can be obtained.

By providing the positioning portion on the optical axis of the light emitting portion and behind the light transmitting / receiving portion, it is not necessary to make the outer shape of the element circular. This makes it possible to easily reduce the size of the device.

When the light transmitting / receiving section is incorporated in the optical head device, the X can be obtained simply by inserting the guide pin into the positioning hole.
The adjustment work in the -Y plane is completed, and the position of the center of rotation for the θ adjustment is simple, so that the assembly equipment can be manufactured at low cost.

Since the positioning portion can be used for assembling the light transmitting / receiving portion and the optical head device, the adjustment work in the XY plane is simplified (ideally, no adjustment).
Equipment for adjustment and assembly is simplified.

[0051]

As is apparent from the above description, according to the first aspect of the present invention, since the positioning portion is located on the optical axis of the light emitting portion or symmetrically disposed with respect to the optical axis. In addition, it is not necessary to make the outer shape of the housing member or the like circular, and if adjustment or positioning with respect to the positioning portion is performed, the optical axis alignment of the light emitting portion is determined as a result, thereby simplifying the work.

According to the second and fifth aspects of the present invention,
By locating the center of the positioning section on the optical axis of the light emitting section, only one positioning section is required, and the configuration is simplified.

According to the third and sixth aspects of the invention,
By arranging the plurality of positioning portions in a symmetrical positional relationship around the optical axis of the light emitting portion, even in a situation where it is difficult to position the center of the positioning portion on the optical axis of the light emitting portion, the positioning portion Is no longer restricted, and the degree of freedom in design can be increased.

According to the fourth aspect of the present invention, the positioning section provided for adjusting or aligning the optical axis of the light emitting section in the light transmitting / receiving section is located on the optical axis of the light emitting section or symmetric with respect to the optical axis. Since the outer shape of the housing member or the like does not need to be circular, the optical head device can be downsized, and a light transmitting / receiving element having an irregular outer shape can be used. Become.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a basic configuration of the present invention.

FIG. 2 is a side view schematically showing a configuration example of an optical integrated device.

FIG. 3 shows an example of a positioning section together with FIG. 4, and FIG. 3 shows an example of a configuration using positioning holes.

FIG. 4 is a diagram showing a relationship between a positioning hole and a guide pin.

FIG. 5 is a diagram showing an example in which two positioning holes are provided.

FIG. 6 is a diagram showing an example in which four positioning projections are provided.

FIG. 7 is a diagram illustrating a configuration example of an optical head device.

FIG. 8 is a side view showing the light transmitting and receiving unit of FIG. 7;

FIG. 9 is a diagram showing the optical integrated device with the lens removed.

[Explanation of symbols]

1, 1A, 1B, 1C, 4 ... optical integrated element, 2a ... light emitting section, 2b ... light receiving section, 5 ... substrate, 8 ... light emitting section, 10 ... positioning section, 10a, 10b ... hole, 12 ... convex section, 13: Optical head device, 15: Transmitting / receiving unit, 17: Lead frame,
19: accommodation member, 20: hole

Claims (6)

[Claims] 1. An integrated optical device having a structure in which a light emitting unit and another optical element or a light receiving unit are housed in a housing member, wherein the housing member or its lead frame or substrate is used for optical axis adjustment or alignment. The positioning part formed in
An optical integrated device provided on an optical axis of a light emitting section or at a position symmetrical with respect to the optical axis. 2. The integrated optical device according to claim 1, wherein the positioning portion is a hole, a projection, or a mark, and the center of the positioning portion is located on the optical axis of the light emitting portion. Optical integrated device. 3. The integrated optical device according to claim 1, wherein the positioning portion comprises a plurality of holes, protrusions, or marks.
An optical integrated device, wherein these are arranged with a symmetrical positional relationship around the optical axis of the light emitting section. 4. An optical head device having an optical integrated type light transmitting / receiving section having a configuration in which a light emitting section and a light receiving section are housed in a housing member, wherein an optical axis adjustment or position of the light emitting section in the light transmitting / receiving section is provided. An optical head device, wherein the positioning member formed on the housing member or its lead frame or substrate for alignment is provided on the optical axis of the light emitting unit or at a position symmetrical with respect to the optical axis. 5. The optical head device according to claim 4, wherein the positioning portion is a hole, a protrusion, or a mark, and the center of the positioning portion is located on the optical axis of the light emitting portion. Optical head device. 6. The optical head device according to claim 4, wherein the positioning portion comprises a plurality of holes, protrusions, or marks.
An optical head device wherein these are arranged in a symmetrical positional relationship around the optical axis of the light emitting section.