JPH09312413A - Photo interrupter and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double molded photo interrupter which can be easily manufactured at low costs, has light emitting and receiving elements provided with projections having a lens function in front thereof, and has a molded part for fixing the light emitting and receiving elements provided with projections having elongate slots made in their front sides, and also to provide a method for manufacturing the interrupter. SOLUTION: The interrupter comprises light emitting and receiving elements 1 and 2 and a molded part 3 made of opaque resin. The elements are provided on their front sides with projections 15 and 25 which have a lens function. The molded part 3 is made by integrally molding surroundings of the elements 1 and 2 so that projections 15 and 25 are spaced as opposed by a constant interval therebetween the thus has a space 31 therebetween. The projections 15 and 25 of the elements 1 and 2 of the molded part 3 are formed on their front sides with narrow slits 32 and 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photo interrupter in which a light emitting element and a light receiving element are opposed to each other through a fixed space and the presence or absence of an object passing through the space is determined.
More specifically, a light emitting element and a light receiving element each having a protrusion having a lens function formed on the front surface are used, and the front surface of the protrusion of the package for fixing the light emitting element and the light receiving element so as to face each other at a constant interval. The present invention relates to a photo interrupter in which a package is formed by integral molding of a resin in a photo interrupter in which a thin slit is provided, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, in a photo interrupter, a light emitting element and a light receiving element are inserted into a case formed in advance so that the light emitting element and the light receiving element face each other and fixed by an adhesive or the like. A case type to be assembled, and a double mold type formed by integrally molding a light emitting element and a light receiving element with a resin opaque to the emission wavelength of the light emitting element as shown in FIGS. There is. The light emitting element and the light receiving element each have a light emitting diode chip (hereinafter referred to as LE
D) or a diode or a phototransistor chip is die-bonded, and other electrodes are wire-bonded to the leads and molded with a resin transparent to the emission wavelength of the LED (primary mold). .

In the case type shown in FIG. 4, the light emitting element 1 and the light receiving element 2 are inserted in a case 4 made of polycarbonate or the like which is opaque to the emission wavelength of the light emitting element 1 and fixed by an adhesive or the like. It is assembled by. In this structure, the light emitting element 1 and the light receiving element 2 are formed with projecting portions 1a and 2a on the front side thereof to serve as convex lenses, thereby condensing light emitted or received, and
The resolution can be increased by forming thin slits 4a on the light emitting surface and the light receiving surface of the case 4, respectively. However, the light emitting element 1 and the light receiving element 2 must be inserted and assembled into the case 4 one by one. Therefore, there are problems that the number of assembling steps is large, the cost is increased, it is difficult to output a constant output due to the variation in mounting accuracy of the light emitting element 1 and the light receiving element 2, and the variation in quality is large. In addition, in FIG.
c is a resin molded product used in place of the adhesive.

On the other hand, the double mold type is shown in FIG.
As shown in the sectional view in FIG. 1, the light emitting element 1 and the light receiving element 2 are fixed by a molding die, and integrally molded by injection of a resin opaque to the emission wavelength of the light emitting element 1 such as PPS (secondary molding). The light emitting element 1 and the light receiving element 2 are fixed to each other by the molded portion 3), so that they can be manufactured easily and accurately.

However, in the case of the double mold, the light emitting element 1
When the protrusions 1a and 2a are formed on the front surface of the light receiving element 2 and the light receiving element 2, it is necessary to prevent the opaque resin of the secondary mold from flowing around the protrusions 1a and 2a. As shown in the cross-sectional explanatory view of the element 1 part together with the optical path L, the opening 3 b of the mold part 3 is inserted into the projection 1 of the light emitting element 1.
It is necessary to provide a larger size than a in total, and it is not possible to form a thin slit. Therefore, there is a problem that the resolution is lowered. On the other hand, as shown in FIG. 7 which is a cross-sectional explanatory view of another example of the light emitting element 1 part along with the optical path L, a thin slit 3a is formed in the mold part 3 unless a protrusion is formed on the front surface of the light emitting element 1. Can be, but light-emitting element 1
However, the light emitting element 1 needs to have a large output, resulting in an increase in cost.

[0006]

As described above, in the case of the conventional photo interrupter case type, there is a problem that the manufacturing cost is high and the performance is not constant or deteriorates. In addition, the conventional double mold type cannot form a thin slit, has a low resolution, and cannot form a lens portion in front of a light emitting element or a light receiving element, resulting in high output. There is.

The present invention has been made in order to solve such a problem, and is a double mold type which is easy to manufacture and low in cost, and has a projection portion having a lens function on the front side of a light emitting element and a light receiving element. An object of the present invention is to provide a photointerrupter having a thin slit formed on the front surface of a protruding portion of a mold portion for fixing a light emitting element and a light receiving element.

[0008]

A photointerrupter according to the present invention comprises a light emitting element and a light receiving element each having a convex portion formed on its front surface so as to have a lens effect, and the light emitting element and the convex portion of the light receiving element. And a mold part made of an opaque resin integrally molding the periphery of the light emitting element and the light receiving element so as to have a space between them, and the light emitting element and the light receiving element of the mold part. A slit narrower than the protrusion is formed on the front surface of the protrusion.

Here, the opaque resin means a resin which is opaque to the emission wavelength of the light emitting element.

[0012] The slits are provided, and between the facing portions of the mold portion facing each other through the space portion and the light emitting element and the light receiving element, over the entire surface of the protruding portion, In addition, by forming a void portion that communicates with the end portion of the mold portion, it is possible to
It is preferable that the light emitting element and the light receiving element of the next mold are pressed against each other, and a mold for closing the protruding portion can be inserted to perform molding, and a thin slit can be formed in the mold portion on the front surface thereof.

A method for manufacturing a photo interrupter according to the present invention is the method for manufacturing a photo interrupter according to claim 1, wherein first and second molds for holding the back surfaces of the light emitting element and the light receiving element, respectively, and the light emitting element. A third mold which is inserted from the lead side of the element and the light receiving element, presses the light emitting element and the light receiving element against the first and second molds respectively, and closes the protrusion, and a side opposite to the lead Fourth inserted from to form the space and the slit
A mold is formed by forming a cavity around the light emitting element and the light receiving element with the mold of (1) and injecting a molding resin into the cavity. By manufacturing by such a method, the photointerrupter described above is formed. Is obtained.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a photo interrupter of the present invention and a method for manufacturing the same will be described with reference to the drawings.

FIG. 1 is a partially cutaway perspective view of an embodiment of a photo interrupter of the present invention, and FIG. 2 is a sectional view taken along line II-II thereof. In FIGS. 1 and 2, 1 is a light emitting element, one LED 12 is bonded to the LED chip 11, and the other electrode of the LED chip 11 is wire bonded to the other lead (not shown) so that the emission wavelength of the LED chip 11 is changed. Is molded with a transparent resin 14 (primary molding), and a projection 15 having a lens effect is formed on the front surface of the LED chip 11. Similarly, the light receiving element 2 is formed by a primary mold by bonding a light receiving element chip such as a photodiode or a phototransistor. 22 and 23 are the leads.

The light emission wavelength of the LED chip 11 is such that the light emitting element 1 and the light receiving element 2 have their projections 15 and 25 facing each other and a space 31 is formed therebetween. Is a molded portion formed by molding with an opaque resin. As shown in FIG. 1, the mold part 3 of the photointerrupter of the present invention has slits 32, 33 on the front surface of the protrusions 15, 25 of the light emitting element 1 and the light receiving element 2 which are smaller than the areas of the protrusions 15, 25. Is formed. These slits 32, 3
In order to form 3, it is necessary to prevent the opaque resin from flowing around the protrusions 15 and 25 of the light emitting element 1 and the light receiving element 2, so that the mold for closing the protrusions 15 and 25 is the lead 12. , 22 and 23, the slits 32 and 33 of the mold portion 3 are provided, and the light-emitting element 1 and the light-receiving element 2 respectively project from the facing portions 34 and 35 which face each other through the space portion 31. Over the entire surface of the shaped portions 15 and 25 and at the end of the molded portion 3 (lead 1
A void portion 36 is formed which communicates with the end portions on the 2, 22, 23 side).

The photo interrupter of the present invention is shown in FIG.
As shown in the cross-sectional view of FIG. 2 along line II-II along with the optical path L thereof, the protrusions 15 and 25 having a lens effect are formed in front of the light emitting element 1 and the light receiving element 2 while Narrow slit 32 in the mold part 3 of the next mold,
33 are formed. As a result, the emitted light can be sufficiently condensed or the received light can be sufficiently condensed and detected, so that the sensitivity is high and the resolution is improved by the slits 32 and 33. Moreover, the light emitting element 1 and the light receiving element 2
Since the case for fixing is integrally formed by the mold portion 3 formed by molding, the manufacturing is easy and the cost is low, and the position accuracy of the light emitting element 1 and the light receiving element 2 is good, and a photointerrupter with good performance is provided. can get.

Next, the manufacturing method of the photo interrupter of the present invention will be described with reference to the example of the mold shown in FIG.

First, the back surface of the light emitting element 1 is inserted into the cavity 51 of the first mold 5, which is the lower mold, and is supported by the projections 52 of the first mold 5, and the leads 12 and 13 are the first. The light emitting element 1 is set so that the protrusion 15 faces upward so as to be placed on the upper surface of the mold 5.

Next, the third mold 7 which is a side mold is inserted from the side of the leads 12 and 13 of the light emitting device 1 so that the light emitting device 1 can be obtained.
And the projection 15 of the light emitting element 1 is closed. Next, a fourth mold, which is a core mold, which forms a space in a facing portion between the light emitting element 1 and the light receiving element 2 and forms slits in front of the protrusions 15 and 25 of the light emitting element 1 and the light receiving element 2. The mold 8 is inserted from the side opposite to the leads 12 and 13.

Thereafter, the projection 25 of the light receiving element 2 is placed on the third mold 7 so as to be closed by the third mold 7, and the second mold, which is the upper mold, is placed. 6 is further placed and the protrusion 6
The light receiving element 2 is pressed down and pressurized by 2.

By injecting the resin into the cavity formed by being surrounded by the first to fourth molds 5 to 8 and then solidifying the resin, the resin does not flow into the protrusions 15 and 25, and before that. A double-molded photointerrupter having thin slits 32 and 33 is formed.

[0021]

According to the present invention, a projection having a lens function is formed on the front side of a light emitting element and a light receiving element, and a thin slit is formed on the front side, while being formed by a double mold. Therefore, a photointerrupter having high sensitivity and high resolution can be obtained. Moreover, it is not necessary to incorporate it in the case, and it is very easy to use, and a high-quality photointerrupter with stable performance can be obtained at low cost.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a photo interrupter of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an explanatory cross-sectional view of an example of a mold for manufacturing the photo interrupter of FIG.

FIG. 4 is a cross-sectional explanatory view of a conventional case type photo interrupter.

FIG. 5 is a cross-sectional explanatory view of a conventional double-mold type photo interrupter.

FIG. 6 is a cross-sectional explanatory view of a light emitting element portion of an example of a conventional double mold type photo interrupter.

FIG. 7 is a cross-sectional explanatory view of a light emitting element portion of another example of the conventional double mold type photo interrupter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light emitting element 2 Light receiving element 3 Mold part 5 1st metal mold 6 2nd metal mold 7 3rd metal mold 8 4th metal mold 15 Projection part 25 Projection part 31 Space part 32 Slit 33 Slit 34 Opposition Part 35 Opposing part 36 Void

Claims (3)

[Claims] 1. A light emitting element and a light receiving element, each of which has a convex portion formed on its front surface so as to have a lens effect, and the convex portions of the light emitting element and the light receiving element face each other at a constant interval, and between them. A mold part made of an opaque resin integrally molding the periphery of the light emitting element and the light receiving element so as to have a space part, and the projecting part on the front surface of the projecting part of the light emitting element and the light receiving element of the molding part. A photo interrupter with narrower slits. 2. The entire surface of the projecting portion is provided between each of the light-emitting element and the light-receiving element and each of the facing portions of the mold portion which are provided with the slit and face each other with the space portion interposed therebetween. The photointerrupter according to claim 1, wherein a void portion is formed across the end portion of the mold portion. 3. The method for manufacturing a photointerrupter according to claim 1, wherein first and second molds respectively holding back surfaces of the light emitting element and the light receiving element, and lead sides of the light emitting element and the light receiving element. A third mold for inserting the light-emitting element and the light-receiving element against the first and second molds and closing the protrusion, and the space part inserted from the side opposite to the lead. A method for producing a photointerrupter, in which a cavity is formed around the light emitting element and the light receiving element with a fourth die for forming a slit, and a molding resin is injected into the cavity to perform molding.