JP2695717B2 - Manufacturing method of transmission type photo interrupter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a transmission type photointerrupter (hereinafter simply referred to as a photointerrupter) for detecting the presence or absence of an object without contact.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIGS. FIGS. 7A, 7B and 7C are a front view, a side view and a front view, respectively, of a conventional light receiving side primary molded body.
FIG. 8 is a plan view, FIG. 8 is a cross-sectional view showing a state in which both primary molds and a slit plate on the light receiving and emitting sides according to the conventional example are inserted into a secondary mold, and FIG. It is a protrusion enlarged view.

[0003] A conventional photointerrupter is shown in FIG.
As shown in (c), the light receiving chip 1 is mounted on the lead terminal 2, the light receiving chip 1 is connected to the other lead terminal 3 with the gold wire 4, covered with the translucent resin 5, and the light receiving side primary molded body Is formed. At this time, the light-receiving chip 5 is formed so that the upper surface of the light-receiving chip of the translucent resin portion 5 has a convex shape 5a. Similarly, a light emitting side primary molded body is formed using the light emitting chip 6 instead of the light receiving chip 1 of the light receiving side primary molded body.

[0004] Next, as shown in FIG. 8, these two primary mold bodies are opposed to each other, inserted into the secondary mold 7, and the L portion of the primary mold protrusion 5 a is inserted into the secondary mold 5. 7 and filled with a light-shielding resin 8 to be integrally molded. At this time, since the L portion is in contact with the secondary mold 7, it is not covered with the light-shielding resin 8 after the secondary molding, and serves as a light path for the primary mold. That is, the width of the light path is determined by changing the size of L.

[0005]

By the way, in the above-mentioned prior art, the width (slit) of the light path is narrowed by shortening the length of the L portion, so that a higher resolution photointerrupter can be obtained. As shown in FIG. 7, the corner of the portion 5a in FIG. 7 actually has some curvature.
The portion L ′ contacting the next mold 7 becomes smaller,
The dimension of L 'is unstable due to the resin molded product and may be 0 in extreme cases. It is difficult to stably mold L' to about 0.1 mm by this method.

Even if L 'can be reduced, the L' portion is pressed afterward at 7a so as to contact the mold 7 during the secondary molding, so that it is difficult to mold the 5a portion in terms of strength. There was a problem that.

In view of the above problems, an object of the present invention is to provide a method of manufacturing a photointerrupter which has a simple manufacturing process and can reliably secure a narrow slit width for narrowing an optical path.

[0008]

In order to achieve the above object, the present invention provides a light emitting and receiving chip mounted on a plurality of light emitting side lead terminals and a plurality of light receiving side lead terminals connected to a common frame at the same pitch. A light-transmitting resin, and a primary mold connecting body that is primary-molded with a light-transmitting resin, and a plurality of light-emitting and light-receiving surfaces of the two primary mold connecting bodies, at least on the light-receiving surface side, corresponding to the light-receiving and light-emitting chips. A slit plate connecting body in which the slit plates are connected with the common frame at the same pitch is overlapped, and the two primary mold connecting bodies including the slit plate connecting body are integrally formed of a light shielding resin so as to face each other.
It is characterized by being molded next.

[0009]

A plurality of light receiving and emitting chips are firstly molded and connected to a primary mold connecting member, and a plurality of metal slit plates corresponding to the light receiving and emitting chips are connected to a slit plate connecting member. Since the two primary mold connecting bodies on the light receiving and emitting sides are secondary molded so as to face each other, the slit plate can be easily set, the positional accuracy is accurate, and a plurality of photointerrupters can be formed in a single process, resulting in production efficiency. Can be improved.

In addition, since the slit plate is made of metal, a narrow slit width can be formed, and a high-resolution and high-reliability photointerrupter without deformation can be obtained.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS.

FIGS. 1 (a), 1 (b) and 1 (c) respectively show
A front view, a side view, a plan view, and FIGS. 2A, 2B, and 2C of a light receiving side primary molded body of the photointerrupter according to the present embodiment.
(C) is a front view, a side view, and a plan view of a slit plate for restricting a light passage, and FIG. 3 is a state in which both the primary mold body and the slit plate on the light receiving and emitting sides are inserted into a secondary mold. 4, FIG. 4 is a sectional view taken along line AA 'of FIG. 3, FIG. 5 is a perspective view of a photo interrupter according to the present embodiment, and FIG. 6 is a primary mold connecting member and a slit plate of the photo interrupter according to the present embodiment. It is a perspective view which shows the process of combining an articulation body.

The same symbols are given to the same functional parts as those in the conventional example shown in FIGS.

Although the photointerrupter according to the present embodiment is manufactured in a state where a plurality of photointerrupters are connected as shown in FIG. 6 described later, a single photointerrupter will be described with reference to FIGS.

As shown in FIG. 1, the light-receiving chip 1 is mounted on the lead terminal 2 and internally connected to the other lead terminal 3 by the gold wire 4 and cast with a thermosetting translucent resin 9, for example, an epoxy resin. Alternatively, a light-receiving side light-transmitting resin body which is primarily molded by a transfer molding method is formed. Similarly, a light emitting side translucent resin body using the light emitting chip 6 instead of the light receiving chip 1 is formed.

Here, the surfaces 9a of the two light-transmitting resin bodies serving as light passages are flat. As shown in FIG. 6, the lead terminals 2 and 3 are integrally connected by a common frame 13 having a positioning hole 13a at the tip.

Next, a slit 1 serving as a light passage in a metal plate.
The slit plate 10 provided with Ob is formed. This slit plate 10 has L-shaped portions 10a at both left and right ends, and a lead portion 10c for insert molding into the secondary molding die 11.
It has. The lead portion 10c is integrally connected at a distal end thereof to a common frame 14 having a positioning hole 14a having the same diameter and pitch as the positioning hole 13a of the common frame 13 made of the transparent resin body.

Next, as shown in FIG. 6, the two primary mold connecting members A and the slit plate connecting members B on the light receiving / emitting side are connected to the positioning holes 13a, 1 of the common frames 13, 14, respectively.
4a are overlapped so as to overlap with each other, and in this state, they are inserted into the secondary mold 11 as shown in FIG. 3, and are integrated by injection molding with a thermoplastic light-shielding resin 12, for example, PPS (polyphenylene sulfide). (Only one of the light receiving / emitting sections is shown in FIG. 6).

Then, after injection molding, the secondary mold 1
Release from the mold 1 to obtain a photo interrupter as shown in FIG. At this time, L-shaped portions 10 are provided at both left and right ends of the slit plate 10.
As shown in FIG. 4, the slit plate 10 is embedded in the light-shielding resin 12 as shown in FIG.

As is clear from the above description, according to the present embodiment, the slit width S can be reduced to 0.1 mm or less because the slit plate 10 for limiting the light path is made of metal. Can be as narrow as the thickness of the slit plate), and since the slit plate 10 is a frame having positioning holes, the position accuracy of the slit plate with respect to the outer shape of the photointerrupter is high and the resolution is high (0.1 mm or less). ) A photo interrupter is obtained. Further, there is an advantage that a large number of pieces can be molded at once, which leads to an improvement in productivity.

In this embodiment, an example is shown in which slit plates are provided on both the light receiving and emitting sides. However, although the effect is lower than in this embodiment, a slit plate may be provided only on the light receiving side.

[0022]

As described above, according to the present invention, each of the primary mold connecting members on the light receiving / emitting side and the metallic slit plate connecting member are simultaneously connected in a multiple-unit manner by the common frame supporting each of them. Since the subsequent molding is performed, the setting of the slit plate is easy, the positional accuracy is accurate, and a plurality of photointerrupters can be simultaneously formed, so that the production efficiency can be improved.

Further, since the slit plate is made of metal, a narrow slit width can be formed, and a high-resolution and high-reliability photointerrupter without deformation can be realized.

[Brief description of the drawings]

FIGS. 1A, 1B, and 1C are a front view, a side view, and a plan view, respectively, of a light-receiving-side primary molded body of a photointerrupter according to an embodiment of the present invention.

FIGS. 2A, 2B, and 2C are a front view, a side view, and a plan view, respectively, of a slit plate according to an embodiment of the present invention that restricts a light passage;

FIG. 3 is a cross-sectional view showing a state where both primary mold bodies and a slit plate on a light receiving and emitting side according to an embodiment of the present invention are inserted into a secondary mold.

FIG. 4 is a sectional view taken along line A-A ′ of FIG. 3;

FIG. 5 is a perspective view of a photointerrupter according to one embodiment of the present invention.

FIG. 6 is a perspective view showing a process of assembling a primary mold connecting member and a slit plate connecting member of a photo interrupter according to an embodiment of the present invention.

FIGS. 7A, 7B, and 7C are a front view, a side view, and a plan view, respectively, of a light-receiving-side primary molded body according to a conventional example.

FIG. 8 is a cross-sectional view showing a state where both primary mold bodies and a slit plate on the light receiving / emitting side according to a conventional example are inserted into a secondary mold.

FIG. 9 is an enlarged view of a projection for an optical path stop of a conventional photointerrupter.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 light receiving chip 2, 3 lead terminal 6 light emitting chip 9 translucent resin 10 slit plate 11 light shielding resin 13, 14 common frame A primary mold connecting body B slit plate connecting body

Claims (1)

(57) [Claims] 1. A primary mold connection in which a plurality of light emitting / receiving chips are mounted on a plurality of light emitting side lead terminals and a plurality of light receiving side lead terminals connected at the same pitch to a common frame, respectively, and primary molded with a translucent resin. A slit plate connection in which a plurality of slit plates corresponding to the light receiving and emitting chips are connected at the same pitch to the common frame on at least the light receiving surface side of the light emitting surface and the light receiving surface of the two primary mold connecting members. Wherein the two primary mold connecting members including the slit plate connecting member are integrally and secondarily molded with a light-shielding resin so as to face each other. .