JP3035083B2 - Transmission type optical coupling device and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission type optical coupling device for detecting the presence or absence of an object without contact, and a method of manufacturing the same.

[0002]

2. Description of the Related Art FIG. 8 is a perspective view showing the appearance of a double-molded transmission type optical coupling device according to a conventional example 1, and FIG.
10 is an external perspective view of a double mold type transmission optical coupling device of Conventional Example 2, and FIG.
3 is shown. In Conventional Examples 1 and 2, each of the light emitting element 1 and the light receiving element 2 is primarily molded with a translucent resin 3 to form a window portion 4 (slit portion) serving as a light entrance and exit.

[0003] In the conventional example 1, the slit 4 is formed by providing a predetermined protruding portion on the side of the light emitting and receiving elements 1 and 2 of the secondary mold so that the secondary mold body corresponding to the protruding portion is provided. A slit 4 (notch) is formed on the other hand.
Then, the light receiving and emitting elements 1 and 2 of the transparent resin for primary molding 3
By providing a protrusion of predetermined width on the side, to form a slit portion 4 (notches) in the secondary mold body corresponding to the projecting portion. By setting the width of the slit portion 4 appropriately,
The resolution of the transmission type optical coupling device is improved.

[0004]

In order to improve the resolution of the transmission type optical coupling device, it is desirable to narrow the slit portion 4 serving as a light entrance / exit, specifically, 0.2 mm.
The following dimensions (resolution) are required.

However, there is a mechanical limitation in reducing the width of the protrusion of the secondary mold in Conventional Example 1 and the width of the protrusion of the primary mold body in Conventional Example 2. For example, even if the width of the protruding portion can be reduced to 0.2 mm or less, a crack or a chip is generated because the structure becomes to be brought into contact with other members of the mold in the mold. Formation is not possible. Conversely, in order to obtain stable formation of the slit portion 4, it is necessary that the width of the projecting portion be wide.

In each slit forming method,
At the time of the secondary molding, only the lower ends of both the primary molded bodies, that is, the ends on the lead terminal side, can be held.
There is a possibility that the optical signal is shifted from a predetermined position (device shake) as shown in FIG.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a transmission type optical coupling device having high resolution and high transmission characteristics and a method of manufacturing the same.

[0008]

The means for solving the problem according to the first aspect of the present invention, as shown in FIG. 2 , detects the presence or absence of an object without contact, and the light emitting element 11 and the light receiving element 13 are connected to each other. Opposite to each other with the passage 15 for the object to be detected interposed therebetween so as to be optically coupled, these are housed in the exterior 21, and the light from the light emitting element 11 is placed on the light emitting surface 28 of the exterior 21 on the light receiving element 13 side. A light emitting window 17 for projecting light from the light emitting element 1, which is projected from the light emitting window 17, is formed on the light receiving surface 29.
Daylighting window 19 for lighting one light to the light receiving element 13
Is formed, the light receiving element width W1 of the light receiving element 13 is set to 0.0 so that the resolution is improved.
5 mm to 0.2 mm, the circumference of each of the elements 11 and 13
The primary mold bodies 12 and 14 are covered with a transparent resin.
Are formed around the primary mold bodies 12 and 14, respectively.
Is covered with light-shielding resin and has a secondary mold body as an exterior
21 is formed, and the light transfer portion of the secondary mold body 21 is
The projection window 32 of the next molding die 31
A lighting window 19 is formed, and the light projecting window 17 and the lighting window 19 are formed.
Is at least one of the protrusions 3 of the secondary mold 31.
Spread toward the other window to increase the strength of 2
It is formed to have an inclined side wall surface (inclined surface) 33 .

[0009]

As shown in FIG. 3, the problem solving means according to the second aspect of the present invention is to form a light emitting side primary molded body 12 by coating the periphery of a light emitting element 11 with a translucent resin, Light receiving side primary molded body 1 covered with translucent resin
4 and the two primary molded bodies 12 and 14 are arranged to face each other across the passage 15 for the object to be detected.
A light transmitting window 17 and a light receiving window 1 for transmitting and receiving light around the areas 2 and 14.
In a manufacturing method of forming the secondary mold body 21 by covering with a light-shielding resin except for the step 9, at least one of the primary mold bodies 12 and 14 is added to the secondary mold die 31 at the time of the secondary molding. To form a mold-side positioning projection 43 for preventing the positional deviation.

[0013] As shown in FIG. 4, the problem solving means according to the third aspect of the present invention is to cover the periphery of the light emitting element 11 with a translucent resin to form the light emitting side primary molded body 12, and to cover the periphery of the light receiving element 13. Light receiving side primary molded body 1 covered with translucent resin
4 and the two primary molded bodies 12 and 14 are arranged to face each other across the passage 15 for the object to be detected.
A light transmitting window 17 and a light receiving window 1 for transmitting and receiving light around the areas 2 and 14.
9 except that the two primary molded bodies 1 are covered with a light-shielding resin to form a secondary molded body 21.
A device-side positioning projection 44 is formed on at least one of the second and the second 14 to abut on the secondary mold 31 during the secondary molding and to prevent positional deviation.

[0012]

[Action] In SUMMARY by the claim 1, in an outer 21 and opposed to accommodating a light emitting element 11 and the light receiving element 13 across the passage 15 of the detected object to optically couple .

At this time, the resolution of the transmission type optical coupling device greatly depends on the light receiving element width W1.
Are formed as narrow as 0.05 to 0.2 mm, the characteristics thereof are improved.

[0014]

[0015]

Further , the protruding portion 3 of the secondary mold 31
By giving the inclined surface to 2, the mechanical strength of the mold 31 is increased, and the tip is made finer. This makes it possible to reduce the widths of the narrowest portions of the light projecting window 17 and the lighting window 19.

In the second aspect , the slit formed by contacting the positioning projections 43 with the primary mold bodies 12 and 14 or in the third aspect , by contacting the positioning projections 44 with the secondary mold 31. Hold the position exactly,
Prevent device shake.

As described above, high resolution can be obtained without narrowing the light projecting window 17 and the lighting window 19 of the mold.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In general, as a method of improving the separation ability of a transmission type optical coupling device (photo interrupter) for detecting the presence or absence of an object without contact, there is a method of mechanically narrowing an optical slit width between the light receiving and emitting devices. However, in this method, there is a limit to minimizing the slit width in consideration of the strength of the slit forming protrusion of the secondary mold or the slit forming protrusion of the primary device. The transmission type optical coupling device of each embodiment of the present invention is intended to narrow the light transmission / reception width between light reception and light emission and to improve its resolution without being mechanically hindered.

(First Embodiment) A transmission type optical coupling device according to a first embodiment of the present invention is shown in FIGS.
As shown in (C), the periphery of the light emitting element 11 is coated with a translucent epoxy resin, for example, to form a light emitting side primary molded body 12 (device), and the periphery of the light receiving element 13 such as a phototransistor or phototriac is formed, for example. A light receiving side primary molded body 14 (device) is formed by being coated with a translucent epoxy resin, and the two primary molded bodies 12 and 14 are arranged to face each other with a passage 15 for an object to be detected therebetween. Except for the light projecting window 17 and the daylighting window 19, the periphery of the light receiving and transmitting windows 12 and 14 is covered with, for example, a light-shielding resin to form a secondary molded body 21 as an exterior.

The light emitting element 11 is, as shown in FIG.
An infrared LED or the like is used, mounted on the light emitting side mounting lead frame 23, and connected to the light emitting side connection lead frame 25 by the thin metal wire 24.

The light receiving element 13 is mounted on a light receiving side mounting lead frame 26 using a phototransistor or a photo triac, and is connected to the light receiving side connection lead frame 27 by a thin metal wire 24. The light receiving element width W1 of the light receiving element 13 is formed narrow as shown in FIG. Since the light receiving element width W1 can be set to a minimum value by an etching process or the like, if it is designed according to a desired resolution, the design dimensions can be easily created. W1 is specifically set to 0.05 to 0.2 mm.

The secondary mold body 21 is formed by injection molding using a thermoplastic resin or a thermosetting resin as shown in FIG.

The light projecting window 17 is, as shown in FIG.
It is arranged at the center of the light emitting surface 28.

On the other hand, the daylighting window 19 is disposed on the light receiving surface 29 so as to be eccentric to the light projecting window 17 in a direction orthogonal to the optical axis and to overlap the daylighting window 19 with a width W2. ing. Here, W2 is specifically 0.05
０．２0.2 mm.

The width W0 of the light projecting window 17 and the daylighting window 19 is determined in consideration of the durability of the projecting portion of the mold member forming the same and stabilization of the shapes of the light projecting window 17 and the daylighting window 19. Therefore, it is set as large as about 0.4 to 0.5 mm.

In the manufacturing process of the transmission type optical coupling device, a light receiving element 13 having a small light receiving element width W1 is used. Then, after the elements 11 and 13 are primarily molded as primary molded bodies 12 and 14 (devices), they are opposed to each other in a secondary mold 31 and secondary molded.

At this time, the light projecting window 17 and the lighting window 19
Is formed by the protruding portion 32 of the secondary mold 31. However, since the resolution is limited in the width dimension W0 of both windows 17, 19, as shown in FIG. Is eccentric with respect to the light projecting window 17 in a direction orthogonal to the optical axis, and is formed so as to have a width W2 so as to overlap with the lighting window 19.

When the light emitting element 11 emits light during use, the resolution of the transmission type optical coupling device largely depends on the light receiving element width W1. Also, as shown in FIG. 1C, the lighting window 19 and the light emitting window 1 decentered from the center of the light receiving and emitting element.
7 is determined by the overlap width W2. Therefore, if these widths W1 and W2 are set to be small to appropriate dimensions at the manufacturing stage, the resolution of the transmission type optical coupling device is greatly improved.

Here, the light receiving element width W1 can generally be accurately determined by etching.
Also, the overlapping width W2 of the lighting window 19 and the light emitting window 17
Are not limited by the mechanical strength, so that both dimensions W1 and W
Since it is possible to make 2 as small as possible, adjustment to an appropriate size can be performed extremely efficiently as compared with the related art.

(Second Embodiment) As shown in FIG. 2, a transmission type optical coupling device according to the present embodiment includes a light transmitting window 17 and a light receiving window 1 in a secondary mold die 31 for forming a secondary molded body 21.
9 is provided with a taper 33 (inclined surface) in the protruding portion 32, thereby increasing the mechanical strength of the secondary mold 31.
This realizes a finer tip. By doing so, the width of the light projecting window 17 and the daylighting window 19 can be 0.15 to 0.2 mm in the narrowest part. Moreover, since the size of the widest part can be set considerably wider than this, the strength of the mold is not impaired. Other configurations are the same as those of the first embodiment, and the description thereof will be omitted.

(Third Embodiment) As shown in FIG. 3, the transmission type optical coupling device of the present embodiment employs an element 1 of a light projecting window 17 and a daylighting window 19.
In order to accurately hold the slit position with respect to 1 and 13, a blur prevention hole 41 for preventing device blur is formed in the secondary mold 31. Along with this,
Each of the primary mold bodies 12 and 14 is added to the secondary mold 31.
A mold-side positioning protrusion 43 may be formed so as to abut on the mold and prevent this positional deviation. Other configurations are the same as those of the first embodiment, and the description thereof will be omitted.

(Fourth Embodiment) As shown in FIG. 4, the transmission type optical coupling device according to the present embodiment is designed to accurately maintain the positions of the elements 11, 13 with respect to the light projecting window 17 and the lighting window 19. Device-side positioning protrusions 44 for contacting the primary mold bodies 12 and 14 with the secondary mold die 31 to prevent positional deviation.
Is formed. Other configurations are the same as those of the first embodiment, and the description thereof will be omitted.

(Fifth Embodiment) As shown in FIG. 5, the transmission type optical coupling device of the present embodiment further includes a primary mold body 12, 1 to further enhance the directivity of light transmission and reception between the elements 11, 13.
The light transmission / reception surfaces 28 and 29 of No. 4 are convexly curved.
Other configurations are the same as those of the first embodiment, and the description thereof will be omitted.

(Sixth Embodiment) As shown in FIG. 6, the transmission type optical coupling device of this embodiment transmits and receives light to and from the primary molded bodies 12 and 14 in order to enhance directivity in transmitting and receiving light to and from the elements 11 and 13. Only the central portions of the surfaces 28 and 29 have a convex curved shape. Other configurations are the same as in the first embodiment,
The description is omitted.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications and changes can be made to the above-described embodiment within the scope of the present invention.

For example, if the light receiving element width W1 of the light receiving element 13 is formed to be narrow, the resolution is sufficiently improved by this alone, so that the width W0 of each of the windows 17, 19 does not necessarily have to be formed small. However, it is not always necessary to perform eccentricity as in the first embodiment. Therefore, for example, as shown in FIG. 7, it may be one covered with a conventional primary mold body 3.

The primary molded bodies 12 and 14 for receiving and emitting light are also provided.
Of these, only one may be fixed by the positioning protrusion 43 of the secondary mold 31 and the other may be fixed by the positioning protrusion 44 of the primary mold bodies 12 and 14. That is, various combinations can be considered by selectively combining the elements of claims 1 to 4, and any of these may be adopted.

Further, the translucent resin of the primary mold bodies 12 and 14 may be of a type that blocks visible light.

[0040]

As is apparent from the above description , according to the first aspect of the present invention, the light receiving element width of the light receiving element is set to 0.0.
Narrow and 5～0.2Mm, and narrower width of the light projecting window or fenestra so as maintain the slightly even intensity comprises a slanted surface on the projecting portion of the secondary molding die, according to claim 2, 3 Since the device projection is prevented by the positioning projection, a high-resolution transmission and high transmission characteristics that could not be achieved with the conventional double-mold transmission type optical coupling device can be obtained in a low-cost and mass-productive method. Type optical coupling device can be produced.

In this case, it is possible to stably form the light-emitting window and the light- receiving window without causing troubles such as cracks or chipping of the projecting portions corresponding to the light-emitting window and the light- receiving window of the mold . There is an excellent effect that not only can the quality of the optical coupling device be easily improved but also the life of the mold itself can be prolonged.

[Brief description of the drawings]

1A and 1B show a transmission type optical coupling device according to a first embodiment of the present invention, wherein FIG. 1A is a perspective view of a primary molded body, FIG. 1B is a view showing a light receiving element width of a light receiving element, and FIG. Cross section of transmission type optical coupling device

FIG. 2 is a partial cross-sectional view of a transmission type optical coupling device according to a second embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of a transmission type optical coupling device according to a third embodiment of the present invention;

FIG. 4 is a partial cross-sectional view of a transmission type optical coupling device according to a fourth embodiment of the present invention.

FIG. 5 is a perspective view of a primary molded body of a transmission type optical coupling device according to a fifth embodiment of the present invention.

FIG. 6 is a perspective view of a primary mold body of a transmission type optical coupling device according to a sixth embodiment of the present invention.

FIG. 7 is a perspective view of a primary mold body of a transmission type optical coupling device according to another example of the present invention.

FIG. 8 is an external perspective view of a transmission type optical coupling device of Conventional Example 1.

FIG. 9 is a longitudinal sectional view of a transmission type optical coupling device of Conventional Example 1.

FIG. 10 is a cross-sectional view of a transmission type optical coupling device of Conventional Example 1.

FIG. 11 is an external perspective view of a transmission type optical coupling device of Conventional Example 2.

FIG. 12 is a longitudinal sectional view of a transmission type optical coupling device of Conventional Example 2.

FIG. 13 is a cross-sectional view of a transmission type optical coupling device of Conventional Example 2.

FIG. 14 is a longitudinal sectional view showing a primary mold device deviation in Conventional Examples 1 and 2.

FIG. 15 is a cross-sectional view showing primary mold device fluctuation in Conventional Examples 1 and 2.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 light emitting element 12 light emitting side primary molded body 13 light receiving element 14 light receiving side primary molded body 15 passage 17 light emitting window 19 lighting window 21 secondary molded body 28 light emitting surface 29 light receiving surface 31 secondary mold 32 protruding portion 33 inclined Surface 43 Mold-side positioning protrusion 44 Device-side positioning protrusion

Claims (3)

(57) [Claims] 1. A device for detecting the presence or absence of an object in a non-contact manner, wherein a light emitting element and a light receiving element are opposed to each other across a passage of the object so as to be optically coupled. The light emitting window for projecting light from the light emitting element to the light receiving element side is formed on the light emitting surface of the exterior,
In an optical coupling device in which a light receiving window for receiving light of the light emitting element projected from the light emitting window to the light receiving element is formed on a light receiving surface of an exterior, a light receiving element width of the light receiving element has a resolution. It is formed to a thickness of 0.05 to 0.2 mm so as to be improved, and a light- transmitting resin is
Mold bodies are formed respectively, around the two primary mold bodies.
Is covered with light-shielding resin and has a secondary mold body as an exterior
Is formed, and a secondary molding is provided in the light transfer section of the secondary mold body.
A projection window and a lighting window are formed at the protruding portion of the
At least one of the light emitting window and the lighting window is a secondary mold
Spread toward the other window to increase the strength of the mold protrusion.
A transmissive optical coupling device, which is formed to have a gradually inclined side wall surface . 2. A light-emitting element is covered with a transparent resin.
To form the primary mold body on the light-emitting side,
Cover with light-sensitive resin to form the primary mold on the light-receiving side,
The two primary mold bodies are opposed to each other with the passage of the object to be detected interposed therebetween.
And a light-transmitting window and a light-transmitting window around the primary molds.
Cover with a light-shielding resin except for the
In the method of manufacturing the transmission type optical coupling device to be formed,
In the secondary mold at the time of the
Abut on at least one of
Forming a mold-side positioning protrusion
A method for manufacturing a transmission type optical coupling device . 3. A light-emitting side primary mold body is formed by covering the periphery of the light-emitting element with a translucent resin, and a light-receiving side primary mold body is formed by covering the periphery of the light-receiving element with a translucent resin. ,
The both said primary molded member to face each other across the passage of the object to be detected, the circumference of both primary molded body was covered with light projection window and lighting window excluding light blocking resin for optical transfer secondary molded body the method of manufacturing a transmission type optical coupling device for forming, the
At least one of the two primary mold bodies has a secondary mode.
To prevent displacement due to contact with the secondary mold during molding
A method for manufacturing a transmission type optical coupling device, comprising forming a device-side positioning projection .