JP3050721B2 - Optical integrated circuit, optical pickup and optical information processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detecting means such as a multi-divided light receiving element or the like which focuses a laser beam on a fine light spot and makes it incident on a recording surface of an information recording medium such as an optical disk. , An optical integrated circuit provided for reading signal information written on an optical disc or the like, an optical pickup including such an optical integrated circuit, and a laser printer including such an optical integrated circuit And an optical information processing device such as an optical distance meter.

[0002]

2. Description of the Related Art An optical pickup for reading signal information recorded on an optical disk is equipped with a servo function for focusing and tracking, and this servo function makes it possible to perform mechanical operations such as surface deflection and eccentricity due to rotation of the optical disk. The optical pickup is made to accurately follow the fluctuation.

Incidentally, in order to improve the followability of the optical pickup and increase its reliability, it is necessary to reduce the size and weight of the optical pickup. That is, in this case, the movable portion of the optical pickup can be driven at high speed, and the adverse effect of inertia can be suppressed.

As one conventional example of a miniaturized and lightened optical pickup responding to such a demand, Japanese Patent Application Laid-Open No. Sho 62-1 is an example.
There is one disclosed in Japanese Patent No. 17150. FIG. 8 shows this optical pickup. Transparent substrate 100 having a rectangular parallelepiped shape
A light emitting element 1001 composed of, for example, a semiconductor laser element is attached to the upper surface of the transparent substrate 1000. Laser diffused light emitted from the light emitting element 1001 toward the inside of the transparent substrate 1000 is formed on the upper surface of the transparent substrate 1000. The optical path is changed by the diffraction grating 1002 in a direction corresponding to the right side in the figure.

Subsequently, the front and back (up and down) of the transparent substrate 1000
Reflection surfaces (total reflection surfaces) 1003, 100 formed on both surfaces
4, 1005 in order, the transparent substrate 1000
Is transmitted in a zigzag pattern. Then, the transparent substrate 100
The light is collimated by a diffraction grating 1006 formed on the upper surface of the optical disk 11 and focused on a recording surface of an optical disk 1110 by an objective lens 1007 separately provided at a position directly above the diffraction grating 1006 with a predetermined distance. Thereby, a light spot is formed on the recording surface of the optical disk 1110.

[0006] The reflected light from the optical disk 1110 is transmitted through the transparent substrate 1000 in a direction corresponding to the left side in the figure along a path reverse to the above, and is formed on the rear surface of the transparent substrate 1000 with a concave lens 1008 formed on the upper surface. The reflected light is reflected by each reflecting surface of the cylindrical lens 1009 and finally detected by the multi-segment light receiving element 1010, whereby the signal information recorded on the disk surface is read. Further, focusing servo and tracking servo are performed using the detection result of the multi-segment light receiving element 1010.

By the way, the optical pickup having the above configuration has
Optical components such as diffraction gratings 1002, 1006, concave lens 1008, cylindrical lens 1009, etc.
Therefore, it is difficult to position these optical components with respect to the transparent substrate 1000, and there is a drawback that the assembly work is complicated and the cost is increased due to the limitation on the assembly accuracy.

In order to solve such a drawback, Japanese Patent Application Laid-Open No. Sho 62-117150 discloses a method of integrally forming an optical element corresponding to an optical component on both the front and back surfaces of a transparent substrate 1000 by using a molding technique. Is disclosed as another embodiment.

However, in another embodiment, a separate objective lens 10 is provided on the transparent substrate 1000 similarly to the above configuration.
07, there is a drawback that a quick assembling operation cannot be performed due to a limitation in assembling accuracy, resulting in an increase in cost. In addition, since a predetermined separation dimension is required between the objective lens 1007 and the diffraction grating 1006, the thickness dimension of the optical pickup is increased as a whole, which has been a bottleneck particularly in reducing the thickness of the optical pickup. .

As a solution to the above disadvantages of the prior art, the present applicant has disclosed in Japanese Patent Application No. 3-332232, for example.
There is one proposed earlier in the issue. FIG. 9 and FIG. 10 show an optical integrated circuit mounted on this optical pickup.

The optical integrated circuit 200 is constructed by assembling an optoelectronic integrated substrate 240 made of a silicon substrate at one end on the upper surface of a transparent substrate 230 having a rectangular parallelepiped shape.
The transparent substrate 230 is formed by a molding method including an engraving technique. That is, as an example, a diffraction grating for pouring a transparent resin material such as PMMA or PC into a mold, and simultaneously forming three beams of 0th-order light and ± 1st-order light on both upper and lower (front and back) surfaces by using an engraving technique. A hologram beam splitter 233 and a hologram collimating lens 234 are formed. Further, the mirror 236 for reflection and the aspherical objective lens 23 are used.
5 are formed.

More specifically, the upper surface 23 of the transparent substrate 230
0a, the aspherical objective lens 23
5, a hologram collimating lens 234 is formed in a portion of the lower surface 230b located directly below the aspherical objective lens 235. Further, the hologram beam splitter 233 is formed at a position slightly deviated from the longitudinal center of the upper surface 230a toward the aspherical objective lens 235. Further, 3 is provided at the longitudinal center of the lower surface 230b.
A diffraction grating 232 for beam formation is formed.

In addition, at one end in the longitudinal direction of the upper surface 230a, there is formed a storage recess 231 having a square hole shape narrowing toward the bottom surface. The housing recess 231 is provided for housing the semiconductor laser element 241 incorporated in the optoelectronic integrated substrate 240 mounted on the upper surface side of the transparent substrate 230 and the submount 243 on which the semiconductor laser element 241 is mounted.

According to such a configuration, the semiconductor laser element 241 is hermetically sealed from the outside in the assembled state, so that the life of the semiconductor laser element 241 does not deteriorate due to adhesion of moisture to the semiconductor laser element 241. Further, the output of the semiconductor laser element 241 is stabilized.

[0015] As shown in FIG.
The light-receiving element 242 for monitoring the output of the semiconductor laser element 241, a control circuit thereof (not shown), a multi-division light receiving element 244 composed of a multi-division photodiode, and a signal processing circuit thereof (not shown) ) Is monolithically assembled. Specifically, it is assembled using an existing manufacturing process technology such as a surface mounting technology. After that, the submount 243 on which the semiconductor laser element 241 is mounted is assembled.

As shown, the submount 243 has a triangular prism shape, and a semiconductor laser element 241 is mounted on the upper end of the inclined surface 243a. The electrical connection between the submount 243 and the optoelectronic integrated substrate 240 is made by wire bonding the submount 243 and the electrode lands 246 formed on the surface of the optoelectronic integrated substrate 240.

A light receiving element 24 as a monitor means
2 receives the laser beam emitted from the semiconductor laser element 241, photoelectrically converts the amount of received light into an electric signal, and supplies the electric signal as a feedback signal to the control circuit. Thereby, the control circuit controls the output level of the semiconductor laser device 241 to a constant value at all times.

The signal processing circuit includes a noise filter, an amplifier, etc., performs signal processing on a detection signal provided from the multi-segment light receiving element 244, and forms an electrode land formed on the surface at one longitudinal end of the optoelectronic integrated board 240. Output to the outside via 245.

According to the optical integrated circuit having such a configuration, the above-mentioned drawbacks of the prior art can be solved by the manufacturing process, and the cost of the optical pickup can be reduced.

However, since the optical integrated circuits shown in FIGS. 9 and 10 have the following problems, there is still room for improvement in manufacturing efficiency and cost reduction.

(1) When mounting the submount 243 on which the light emitting element including the semiconductor laser element 241 is mounted on the opto-electronic integrated board 240, it is extremely high so as not to impair the function of the optical system of this optical integrated circuit. It is necessary to adjust the emission position and the emission direction of the laser light with high accuracy. Therefore, there is a problem that a complicated manufacturing process is required at the time of mounting, resulting in poor manufacturing efficiency and an increase in cost.

Such a problem arises because the semiconductor laser element 24
The same applies to the case where the light emitting element made of 1 is directly mounted on the optoelectronic integrated substrate 240.

(2) The manufacturing process of the optoelectronic integrated substrate 240 includes a light receiving element 242, a signal processing circuit, and an electrode land 24.
A process using an integrated circuit manufacturing process for integrating 5, 246, etc. on the optoelectronic integrated substrate 240, and a submount 243 on which a light emitting element including a semiconductor laser element 241 is mounted.
Is mounted on the opto-electronic integrated board 240, and an assembly step of wire bonding the submount 243 and the electrode lands 246 on the opto-electronic integrated board 240 is performed. Therefore, it is difficult to unify the manufacturing process. For this reason, both processes must be performed in a divided manner, and it takes a long processing time. In this respect, there is a problem that the cost is increased.

Such a problem arises because the semiconductor laser element 24
The same applies to the case where the light emitting element made of 1 is directly mounted on the optoelectronic integrated substrate 240.

As a solution to the problems of the prior art, the applicant of the present application has subsequently filed Japanese Patent Application No. Hei.
There is an optical pickup proposed in 07408.

FIGS. 11 and 12 show an optical integrated circuit mounted on this optical pickup. This optical integrated circuit 100
Means that the optoelectronic integrated substrate 1 is used when molding a transparent resin material.
10 is manufactured. As shown in FIG. 11, the opto-electronic integrated substrate 110 is made of a compound semiconductor such as a GaAs / GaAlAs-based substrate or an InP / InGaAsP-based substrate. An electronic component including an electronic integrated circuit 112 and an electronic integrated circuit (not shown) and an optical component including a hologram beam splitter 114 and a hologram collimating lens 115 are provided.

Here, the light emitting element 111 and the light receiving element 112
The electronic integrated circuit is formed directly on the optoelectronic integrated substrate 110 by using an existing semiconductor process technology. The hologram beam splitter 114 and the hologram collimating lens 115 are also formed by carving a surface groove shape on the optoelectronic integrated substrate 110 by using a semiconductor process technique.

The transparent resin molded body 120 for taking in the optoelectronic integrated substrate 110 during molding is, for example, PMMA,
A transparent resin such as a PC is used as a material, and the transparent resin is poured into a mold so that the optoelectronic integrated circuit 110 is taken in. At this time, the aspherical objective lens 121 and the reflection surfaces 122a, 122b, 122c and 122d are formed on the upper surface 120a of the transparent resin molded body 120 having a rectangular parallelepiped shape.

More specifically, the aspherical objective lens 121 is formed to protrude at one end in the longitudinal direction corresponding to the right end in the figure of the upper surface 120a of the transparent resin molded body 120.
Further, the reflecting surfaces 122b, 122c, 122d
0a is formed from the center in the longitudinal direction to the other end in the longitudinal direction. Further, the reflection surface 122a is formed as an inclined surface on the end surface at the other end in the longitudinal direction.

Then, a hologram collimating lens 115 is formed on a surface portion of the optoelectronic integrated substrate 110 located directly below the aspherical objective lens 121. The hologram beam splitter 114 is formed on the optoelectronic integrated substrate 110 at the center in the longitudinal direction.

Light emitting device 111 composed of a semiconductor laser device
Is formed on the other end of the optoelectronic integrated substrate 110 in the longitudinal direction, with its end face flush with the end face 110b of the optoelectronic integrated substrate 110. Light emitting element 111 to optoelectronic integrated substrate 1
The optical path of the laser beam emitted toward the inside of the substrate 10 is parallel to the surface of the optoelectronic integrated substrate 110 and the end surface 11
0b. The light receiving element 112 is formed on the surface of the optoelectronic integrated substrate 110 at a position slightly deviated from the hologram beam splitter 114 toward the other end in the longitudinal direction.

The light receiving element 112 is composed of a multi-segmented photodiode, and includes an optoelectronic integrated substrate 110 and a transparent resin molded body 12.
The light propagating between 0 is received and photoelectrically converted into an electric signal. Further, the electronic integrated circuit processes a detection signal given from the light receiving element 112 and outputs the processed signal to the outside via an electrode land (not shown) formed on the optoelectronic integrated substrate 110.

When the optical integrated circuit 100 is used for an optical pickup, the aspherical objective lens 121 is disposed so as to be located below the recording surface of the optical disk. Light emitting element 11
The laser beam emitted from 1 is reflected by the reflection surfaces 122a, 1a
After being reflected by 22 b, it is reflected by a reflection surface 122 c via a hologram beam splitter 114 formed on the optoelectronic integrated substrate 110, and is guided to a hologram collimating lens 115 formed on the optoelectronic integrated substrate 110. Subsequently, the light is collimated by the hologram collimating lens 115, and the collimated light is condensed by the aspherical objective lens 121 and is irradiated as a light spot on the recording surface of the optical disc.

On the other hand, the reflected light from the optical disk follows the reverse path to that described above, and the hologram beam splitter 114
And after being reflected by the reflecting surface 122d, it enters the light receiving element 112. The multi-segmented photodiode of the light receiving element 112 detects the reflected light from the optical disk, photoelectrically converts the detected light, and provides the light to the electronic integrated circuit.
The electronic integrated circuit outputs signal information, a tracking error signal, and a focusing error signal recorded on the optical disc by performing signal processing on the applied electric signal.

When the optical integrated circuit 100 is used for an optical pickup, the focusing actuator and the tracking actuator are used for the optical integrated circuit 10.
0. Focusing actuators are
The optical pickup, that is, the optical integrated circuit 100 is servo-controlled based on the focusing error signal. The tracking actuator servo-controls the optical integrated circuit 100 based on the tracking error signal.

According to such an optical integrated circuit 100, when the transparent resin molded body 120 is molded with a transparent material, the optical integrated circuit 100 is manufactured by taking in the optoelectronic integrated substrate 110, so that the above-mentioned problems of the prior art can be solved. Thus, a low-priced optical pickup can be realized.

[0037]

However, FIG.
The optical integrated circuit 100 shown in FIG. 12 has the following new problem.

(1) As described above, the optical integrated circuit 100 is manufactured by incorporating the optoelectronic integrated substrate 110 when molding a transparent resin material. At this time, the upper surface 120a of the transparent resin molded body 120 is provided with an aspherical objective. The lens 121 is formed. If the positional relationship between the optoelectronic integrated substrate 110 and the aspherical objective lens 121, particularly the angular positional relationship, deviates from the designed positional relationship during molding, the light is condensed by the aspherical objective lens 121. Since a large ray aberration occurs in the light and it becomes impossible to narrow down to a minute light spot on the recording surface of the optical disk, there is a possibility that the signal information recorded on the optical disk surface may not be read. That is, the reliability of the optical pickup may be impaired.

In order to solve such a problem, the positional relationship between the optoelectronic integrated substrate 110 and the aspherical objective lens 121 may be maintained with high precision. However, in order to do so, a complicated manufacturing process is required, and it takes time to manufacture, and it is difficult to reduce the cost. At present, due to such cost restrictions, there is a limit in improving the reliability of the optical pickup.

Such a problem arises because instead of molding the optoelectronic integrated substrate with a transparent resin, the optoelectronic integrated substrate 110 is made of a transparent material molded body 12 made of a transparent resin or a glass material.
The same applies to an optical integrated circuit configured to be housed inside the optical integrated circuit.

(2) The optical integrated circuit 100 has an aspherical objective lens 121 on an upper surface 120 a of a transparent resin molded body 120.
Is bulged, and accordingly, it is difficult to reduce the size of the optical integrated circuit 100, especially to reduce the thickness.

Such a problem arises because instead of molding the optoelectronic integrated substrate with a transparent resin, the optoelectronic integrated substrate 110 is made of a transparent material molded body 12 made of a transparent resin or a glass material.
The same applies to an optical integrated circuit configured to be housed inside the optical integrated circuit.

An object of the present invention is to solve such disadvantages of the prior art, and to provide an optical integrated circuit which can simplify a manufacturing process, improve mass productivity and significantly reduce costs. With the goal.

Another object of the present invention is to provide an optical integrated circuit that can be reduced in size and thickness and that can significantly improve reliability.

Another object of the present invention is to provide an optical pickup and an optical information processing apparatus that can enjoy the advantages of such an optical integrated circuit.

[0046]

An optical integrated circuit according to the present invention comprises:
An optoelectronic integrated substrate in which a light emitting element, a light receiving element, a reflection type hologram beam splitter, and a reflection type hologram having a condensing function are formed directly on the same surface of the same semiconductor substrate by using a semiconductor process technology. A reflection surface is formed on the upper surface and the inclined surface of the longitudinal end surface , and the inside has a transparent body serving as an optical path, and is molded so as to take the optoelectronic integrated substrate into the inside of the transparent body. Comprising the light emitting element and the optoelectronic integrated
Light emitted in a direction parallel to the longitudinal direction of the substrate is transmitted through the reflecting surface of the inclined surface of the longitudinal end surface of the transparent body.
To face the reflective surface of the upper surface of the light emitting element is the light
The electronic integrated substrate is disposed at the longitudinal end, thereby achieving the above object.

In the optical integrated circuit of the present invention, a light emitting element, a light receiving element, a reflection type hologram beam splitter and a reflection type hologram having a condensing function are formed on a same semiconductor substrate on the same surface. and optoelectronic integrated substrate formed directly by using a semiconductor process technology, the upper surface
A reflection surface is formed on the inclined surface of the longitudinal end surface , and
An optoelectronic integrated substrate having a transparent body having an optical path inside.
Is mounted so as to be accommodated inside the transparent body , and the light-emitting element extends in the longitudinal direction of the optoelectronic integrated substrate.
The light emitted in a direction parallel to the longitudinal direction of the transparent body
The light-emitting element is disposed on the optoelectronic integrated substrate so that the light-emitting element faces the reflection surface on the upper surface of the transparent body via the reflection surface of the inclined surface .
It is arranged at the longitudinal end, thereby achieving the above object.

An optical pickup according to the present invention includes the optical integrated circuit according to the first or second aspect.

An optical information processing apparatus according to the present invention is an optical information processing apparatus used for a laser printer, an optical distance meter, and the like, and includes an optical integrated circuit according to claim 1 or 2.

[0050]

SUMMARY OF] According to the above configuration, the light emitting element composed of a semiconductor laser element, the light receiving element, the reflection-type hologram beam splitter, and the reflection-type hologram having a light condensing function
And can be integrally formed on the same surface on the same semiconductor substrate by using a semiconductor process technology, it is possible to simplify the manufacturing process. Therefore, the efficiency of manufacturing efficiency can be improved.

Further, since the reflection type hologram having the light condensing function is provided, it is not necessary to bulge the aspherical objective lens required in the above prior art. Therefore, a thin, small, and lightweight optical integrated circuit can be realized. Further, the reliability can be improved.

[0052]

Examples of the present invention will be described below.

(Embodiment 1 of Optical Integrated Circuit) FIGS. 1 and 2
Shows an optical integrated circuit according to a first embodiment of the present invention. The optical integrated circuit 1 according to the first embodiment is manufactured by incorporating the optoelectronic integrated substrate 10 into a transparent resin material when molding the same. That is, the optoelectronic integrated substrate 10 is taken into the inside of a rectangular parallelepiped transparent resin molded body 20 produced by molding a transparent resin material.

As shown in FIG. 2, this optoelectronic integrated substrate 1
0 is a GaAs / GaAlAs-based substrate, InP / InG
On the upper surface of a substrate made of a compound semiconductor such as an aAsP-based substrate, a light emitting element 11, a light receiving element 12, an electronic device such as an electronic integrated circuit (not shown), a hologram beam splitter 14, and a condensing function are provided. An optical component including the hologram lens 15 and the like is provided.

Electronic devices such as the light emitting element 11, the light receiving element 12, and an electronic integrated circuit (not shown) are formed directly on the optoelectronic integrated substrate 10 by using an existing semiconductor process technology such as a surface mounting technology. Similarly, optical components such as the hologram beam splitter 14 and the hologram lens 15 are formed by engraving a groove shape at a predetermined position on the surface of the optoelectronic integrated substrate 10 using an existing semiconductor process technology and also using an engraving technology.

The transparent resin molded body 20 is formed by, for example, using a transparent resin such as PMMA or PC as a material, pouring the resin into a mold, and taking the optical integrated circuit 10 therein. At this time, the light incidence / emission surface 21 and the reflection surfaces 22a, 22b, 22c are formed on the upper surface of the transparent resin molded body 20.
And 22d are formed.

More specifically, the light incident / exit surface 21 is formed at one end in the longitudinal direction corresponding to the right end in the figure on the upper surface 20a of the transparent resin molded body 20. Also, the reflection surface 22
b, 22c, and 22d are reflection surfaces 22c, 22d, and 2d from the center in the longitudinal direction of the upper surface 20a to the other end in the longitudinal direction.
2b. The reflection surface 22a is formed on an inclined surface provided on the other end surface in the longitudinal direction of the transparent resin molded body 20.

A hologram lens 15 having a light condensing function is formed in a portion of the optoelectronic integrated substrate 10 located immediately below the light incident / exit surface 21. Further, the hologram beam splitter 14 is formed at a central portion in the longitudinal direction of the optoelectronic integrated substrate 10.

Further, the light emitting device 11 composed of a semiconductor laser device is formed at the other end in the longitudinal direction of the optoelectronic integrated substrate 10 with its emission surface flush with the end surface 10b of the optoelectronic integrated substrate 10. Therefore, the laser beam emitted from the emission surface of the light emitting element 11 is parallel to the surface of the optoelectronic integrated substrate 10 and is perpendicular to the end face 10b. A light receiving element 12 is formed on the surface of the optoelectronic integrated substrate 10 at an intermediate position between the light emitting element 11 and the hologram beam splitter 14.

As shown in FIG. 2, the light receiving element 12 is composed of a multi-segmented photodiode, receives light propagating between the optoelectronic integrated substrate 10 and the transparent resin molded body 20, and photoelectrically converts the light into an electric signal. The detection output of the light receiving element 12 is given to an electronic integrated circuit electrically connected to the light receiving element 12. The electronic integrated circuit includes a signal processing circuit including a noise filter, an amplifier, and the like, and is formed at a predetermined position on the optoelectronic integrated substrate 10. The electronic integrated circuit processes the detection signal given from the light receiving element 12 and outputs the processed signal to the outside via an electrode land (not shown) formed on the optoelectronic integrated substrate 10.

When the optical integrated circuit 1 having such a structure is used for an optical pickup, the light incident / exit surface 21 is disposed below the recording surface of the optical disk. The operation when the optical integrated circuit 1 is used for an optical pickup will be described below.

The laser beam emitted from the light emitting element 11 in parallel to the surface of the optoelectronic integrated substrate 10 is reflected on the reflection surface 22 a of the transparent resin molding 20 for molding the optoelectronic integrated substrate 10.
Then, the light is reflected obliquely upward, and then re-reflected by the reflection surface 22b formed on the upper surface of the transparent resin molded body 20, and then guided to the hologram beam splitter 14 formed on the optoelectronic integrated substrate 10. Subsequently, the light is reflected by the reflection surface 22c via the hologram beam splitter 14, and is guided to the hologram lens 15 formed on the optoelectronic integrated substrate 10.
The light guided to the hologram lens 15 is condensed by the hologram lens 15 and is converted into a condensed light beam. The condensed light beam is irradiated as a light spot on the recording surface of the optical disc 303 (see FIG. 7) via the light beam entrance / exit surface 21 formed right above the hologram lens 15.

The reflected light from the optical disk 303 is guided to the position of the hologram beam splitter 14 along a path opposite to the above, and after being reflected downward by the reflection surface 22d, enters the light receiving element 12. The multi-segment photodiode forming the light receiving element 12 detects the reflected light from the optical disk 30, photoelectrically converts the detected light, and gives the electronic integrated circuit 1. The electronic integrated circuit performs signal processing of an input signal and records signal information recorded on the optical disc 303;
A tracking error signal and a focusing error signal are output.

When the optical integrated circuit 1 is used for an optical pickup, a focusing actuator and a tracking actuator are mounted on the optical integrated circuit 1. As a focusing actuator,
For example, a focusing coil is used. Further, a pair of tracking coils is used as the tracking actuator. Such an actuator is disclosed in Japanese Patent Application No. 3-33 previously proposed by the present applicant.
This is described in detail in US Pat.

The focusing actuator drives the optical integrated circuit 1 in the focusing direction based on a focusing error signal given from the electronic integrated circuit to perform focusing servo. Similarly, the tracking actuator performs tracking servo by driving the optical integrated circuit 1 in the track direction based on the tracking error signal.

According to the above configuration, the light emitting element 1
1. An electronic device such as a light receiving element 12 and an electronic integrated circuit, and optical components such as a reflection type hologram beam splitter 14 and a hologram lens having a condensing function are combined with an existing semiconductor process technology such as a surface mounting technology including an engraving technology. , The optoelectronic integrated substrate 1 is placed inside the transparent resin molded body 20.
Since it can be formed integrally with the optoelectronic integrated circuit 1 in which 0 is taken in, the manufacturing process can be significantly simplified as compared with the above-described prior art. Therefore, the efficiency of manufacturing efficiency can be improved.

Further, since a reflection type hologram having a light condensing function is provided, it is not necessary to bulge the aspherical objective lens required in the prior art. Therefore, a thin, small, and lightweight optical integrated circuit can be realized. Further, the reliability can be improved.

FIGS. 3 and 4 show modifications of the optical integrated circuit 1. FIG. In this modified example, the mounting mode of the light emitting element 11 to the optoelectronic integrated substrate 10 is different from that of the above embodiment, and the laser beam emitted from the emission surface is mounted so as to be perpendicular to the surface of the optoelectronic integrated substrate 10. . For this reason, in this modification, the inclined surface 22a is
Is formed above. Further, as shown in FIG. 4, in this modification, since it is not necessary to emit a laser beam from the end face of the optoelectronic integrated substrate 10, the light emitting element 11 is formed at the other end in the longitudinal direction of the optoelectronic integrated substrate 10. . The operation will be described below.

The laser beam emitted from the light emitting element 11 is reflected by the reflection surface 22a,
It is guided to the hologram beam splitter 14 formed above. Subsequently, after being reflected by the hologram beam splitter 14, it is reflected obliquely downward by the reflection surface 22 c formed on the upper surface of the transparent resin molded body 20, and
The hologram lens 15 is formed on the hologram lens 15. The hologram lens 15 converts this reflected light into a condensed light beam. Subsequently, the condensed light beam is irradiated as a light spot on the recording surface of the optical disc 303 (see FIG. 7) via the light beam entrance / exit surface 21 formed right above the hologram lens 15.

Thereafter, in the same manner as in the above embodiment, the optical disk 3
The reflected light from the recording surface of No. 03 is received by the light receiving element 12 and photoelectrically converted. Finally, the electronic integrated circuit outputs the signal information, tracking error signal and focusing error signal recorded on the optical disk 303 to the outside.

According to this modification, there is an advantage that the method for forming the light emitting element 11 on the optoelectronic integrated substrate 10 is simplified.

Parts corresponding to those in the above embodiment are denoted by the same reference numerals, and detailed description is omitted.

(Embodiment 2 of Optical Integrated Circuit) FIG. 5 shows Embodiment 2 of the optical integrated circuit of the present invention. The optical integrated circuit 1 according to the second embodiment is manufactured by mounting the optoelectronic integrated substrate 10 so as to be housed in a transparent material molded body 30 made of a transparent resin or a glass material. Optoelectronic integrated substrate 1 of the second embodiment
0 is the same as that of the optoelectronic integrated substrate 10 of the first embodiment shown in FIG.

The transparent material molded body 30 is, for example, PM
A transparent resin or glass material such as MA or PC is used as a material, and the transparent resin or glass material is poured into a mold and formed. At this time, the light entrance / exit surfaces 3 are provided on both front and back surfaces of the transparent material molded body 30.
1. A reflection surface 32a, 32b, 32c, 32d and a concave portion 33 are formed. The optoelectronic integrated substrate 10 is mounted so as to be housed in a concave portion 33 formed on the lower surface 30 b of the transparent material molded body 30.

Specifically, the light incident / exit surface 31 is formed at one longitudinal end of the upper surface 30 a of the transparent material molded body 30. The reflecting surfaces 32b, 32c, and 32d are formed on the upper surface 30a.
Are formed in the order of the reflection surfaces 32c, 32d, and 32b from the center in the longitudinal direction to the other end in the longitudinal direction. Further, a reflection surface 32 is provided on the other end surface in the longitudinal direction of the transparent material molded body 30.
a is formed as an inclined surface.

A recess 33 for accommodating the transparent material molded body 30
Has two types of concave portions 33a and 33b, and the transparent material molded body 30 is housed in a concave portion 33b having a depth substantially equal to the thickness of the transparent material molded body 30, and corresponding longitudinal and width dimensions. . On the other hand, the depth of the rectangular hole-shaped concave portion 33a provided continuously with the other longitudinal end of the concave portion 33b is slightly deeper than the depth of the concave portion 33b. The optoelectronic integrated substrate 10 is housed and mounted in the recess 33b such that the light emitting element 11 is located at the position of the recess 33a. Specifically, this attachment is performed using an adhesive whose optical characteristics such as the refractive index are as close as possible to those of the transparent material.

Since the other components and the operation principle are the same as those in the first embodiment, the corresponding numbers are given and the detailed explanation is omitted.

FIG. 6 shows a modification of the optical integrated circuit 1 of the second embodiment. The optical integrated circuit 1 of this modification uses the same optoelectronic integrated substrate 10 as the optoelectronic integrated substrate 10 of the modification shown in FIG. In such a configuration, the laser beam emitted from the light emitting element 11 is reflected on the reflection surface 3 formed on the upper surface 30 a at the other end in the longitudinal direction of the transparent material molded body 30.
After being reflected by 2a, the light passes through a hologram beam splitter 14 formed on the optoelectronic integrated substrate 10 and a reflection surface 32c.
And is guided to the hologram lens 15 formed on the optoelectronic integrated substrate 10, and is converted into a condensed light beam by the hologram lens 15. Subsequently, the condensed light beam is irradiated as a light spot on the recording surface of the optical disk 303 (see FIG. 7) via the light beam entrance / exit surface 31.

Since the subsequent operation principle is the same as that of the second embodiment, the corresponding parts are denoted by the same reference numerals and detailed description thereof will be omitted.

Hereinafter, a method of designing the reflection type hologram lens 15 having the condensing function formed on the optoelectronic integrated substrate 10 of the first and second embodiments will be described. The following describes an example in which this is used.

FIG. 7 shows an optical arrangement in designing the hologram lens 15 in this case. In the figure, a point O in a medium 301 (transparent resin molded body) made of a transparent resin or a glass material and a point R on the recording surface of the optical disk 303 are directed toward the hologram lens 311 from the object light, respectively. And spherical waves 321 and 322 as reference light
Emits. At this time, the spherical wave 322 from the point R is
3 through the space 302 and the transparent substrate 301a (optoelectronic integrated substrate),
It becomes 3.

Here, the hologram pattern of the hologram lens 311 is defined by the mutual interference between the spherical wave 321 and the aspherical wave 323, and is expressed as a curve in which the phase difference defined by the following equation (1) is an integral multiple of π. Is done.

[0083]

(Equation 1)

Where Φ _o is the phase of the spherical wave on the hologram lens 311 when the point O is the light source, and Φ _R is the hologram when the light source is the point R assumed to be in the transparent material 301. The phase of the spherical wave on the lens 311 surface,
x and y are coordinates on the surface of the hologram lens 311; λ is the wavelength of light emitted from a light source in the air;
01.

The third term in the above equation (1) is a term that gives optical aberration, and the aberration of the light spot on the recording surface on the optical disk 303 during reproduction is determined by optimally selecting the coefficient C _ij and the orders i and j. Can be minimized.

More specifically, a ray tracing simulation is performed by the optical system having the arrangement shown in FIG. 7 to determine the wavefront aberration on the recording surface on the optical disk 303, and the above-mentioned ( 1) The coefficient C _ij in the equation is determined by a mathematical method such as a damped least squares method (DLS method).

Then, the coefficient C thus determined
_A hologram lens 311 is designed according to _{ij, and} an optical integrated circuit of the present invention including such a hologram lens 311 is manufactured by the above-described method.

In the above description, the optical integrated circuit of the present invention,
Although only the optical pickup as an application example of the optical integrated circuit has been described, the optical integrated circuit of the present invention can be similarly applied to an optical information processing device such as a laser printer or an optical distance meter.

For example, when applied to a laser printer, a semiconductor laser element is driven in response to an image signal sent from an image processing unit, and a laser beam transmitted through an optical integrated circuit is transmitted to a photosensitive drum or the like. This is achieved by a configuration that exposes the image forming means.

When the present invention is applied to an optical distance meter, it is achieved by a configuration utilizing a deviation of a light receiving position of reflected light from a measuring object with respect to a multi-divided light receiving element. Further, the present invention can be applied to other optical information processing apparatuses such as an image scanner.

[0091]

According to the optical integrated circuit according to the first or second aspect, the light emitting device including the semiconductor laser device and the light receiving device
Since the mirror , the reflection hologram beam splitter , and the reflection hologram having the light condensing function can be integrally formed by using the semiconductor process technology, the manufacturing process can be simplified. Therefore, it is possible to realize an optical integrated circuit capable of improving mass productivity and significantly reducing costs.

Further, since the reflection type hologram lens having the condensing function is provided, it is not necessary to bulge the aspherical objective lens required in the prior art from the surface of the optoelectronic integrated substrate. Therefore, a thin, small, and lightweight optical integrated circuit can be realized. Further, since no large ray aberration is generated, the reliability can be improved.

Further, according to the optical pickup of the third aspect, an optical pickup which can enjoy the effects of such an optical integrated circuit can be realized.

According to the optical information processing apparatus of the fourth aspect, it is possible to realize an optical information processing apparatus such as a laser printer, an optical distance meter and an image scanner which can enjoy the effects of such an optical integrated circuit.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing Embodiment 1 of an optical integrated circuit of the present invention.

FIG. 2 is a perspective view showing an optoelectronic integrated substrate of the optical integrated circuit shown in FIG.

FIG. 3 is a side sectional view showing a modification of the first embodiment of the optical integrated circuit of the present invention.

FIG. 4 is a perspective view showing an optoelectronic integrated substrate of the optical integrated circuit shown in FIG. 3;

FIG. 5 is a side sectional view showing Embodiment 2 of the optical integrated circuit of the present invention.

FIG. 6 is a side sectional view showing a modified example of the optical integrated circuit according to the second embodiment of the present invention.

FIG. 7 is a side sectional view showing a method for designing a hologram lens formed in the optical integrated circuit of the present invention.

FIG. 8 is a side sectional view showing a conventional example of an optical pickup.

FIG. 9 is a side sectional view showing an optical integrated circuit previously proposed by the present applicant.

FIG. 10 is a perspective view showing an optoelectronic integrated substrate of the optical integrated circuit shown in FIG. 9;

FIG. 11 is a side sectional view showing still another optical integrated circuit proposed by the present applicant.

FIG. 12 is an exploded perspective view of the optical integrated circuit shown in FIG.

[Explanation of symbols]

 Reference Signs List 1 optical integrated circuit 10 optoelectronic integrated substrate 10a upper surface of optoelectronic integrated substrate 10b end face of optoelectronic integrated substrate 11 light emitting element 12 light receiving element 14 hologram beam splitter 15 hologram lens 20 transparent resin molded body 21 light incident / exit surfaces 22a, 22b, 22c, 22d Reflective surface 30 Transparent material molded body 30a Upper surface of transparent resin molded body 31 Light incident / exit surface 32a, 32b, 32c, 32d Reflective surface 301 Medium made of transparent material 301a Transparent substrate 302 Space 303 Optical disk 311 Hologram lens 321 322 Spherical wave 323 Aspheric wave

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masahiro Kawamura 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Yoshio Yoshida 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Sharp shares In-company (56) References JP-A-1-303638 (JP, A) JP-A-6-139612 (JP, A) JP-A-4-219640 (JP, A) (58) Fields investigated (Int. . ^7, DB name) G11B 7/135

Claims (4)

(57) [Claims] 1. A light emitting element, a light receiving element, a reflection type hologram beam splitter, and a reflection type hologram having a condensing function, which are formed by a semiconductor laser element, are directly formed on the same surface of the same semiconductor substrate by using a semiconductor process technology. A reflection surface is formed on the formed optoelectronic integrated substrate and the upper surface and the inclined surface of the longitudinal end surface, and a transparent body having an optical path inside is provided. The optoelectronic integrated substrate is taken into the transparent body. In parallel with the longitudinal direction of the optoelectronic integrated substrate from the light emitting element
The light emitted in various directions is inclined by the longitudinal end face of the transparent body.
To face the reflective surface of the upper surface of the transparent body through the reflecting surfaces of the inclined surface, the light emitting element longitudinal direction of the optoelectronic integrated substrate
Disposed toward the end light collecting product circuit. 2. A light emitting element, a light receiving element, a reflection type hologram beam splitter, and a reflection type hologram having a condensing function, which are formed by a semiconductor laser element, are directly formed on the same surface of the same semiconductor substrate by using a semiconductor process technology. A reflection surface is formed on the formed optoelectronic integrated substrate and the inclined surface of the upper surface and the end surface in the longitudinal direction, and a transparent body having an internal optical path is provided. The optoelectronic integrated substrate is housed inside the transparent body. Attached from the light emitting element parallel to the longitudinal direction of the optoelectronic integrated substrate
The light emitted in various directions is inclined by the longitudinal end face of the transparent body.
To face the reflective surface of the upper surface of the transparent body through the reflecting surfaces of the inclined surface, the light emitting element longitudinal direction of the optoelectronic integrated substrate
Disposed toward the end light collecting product circuit. 3. An optical pickup comprising the optical integrated circuit according to claim 1. 4. An optical information processing apparatus for use in a laser printer, an optical distance meter, or the like, comprising: the optical integrated circuit according to claim 1 or 2.