JPH05110129A - Manufacture of transmission type photo-interruptor - Google Patents

Abstract

(57) [Abstract] [Purpose] To realize a high-resolution, high-reliability transmissive photointerrupter with a simple manufacturing method, high production efficiency, and a narrow slit portion of a slit plate. [Structure] A primary mold connecting body 13 on the light receiving and emitting side, in which a plurality of light emitting and receiving chips are respectively primary molded, and a slit plate connecting body 14 made of metal are superposed, and in this state, the slit plate connecting body 14 is included. It is characterized in that the two primary mold connecting bodies on the light receiving and emitting sides are secondarily molded with the light shielding resin 8 so as to face each other.

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 transmissive photo interrupter (hereinafter simply referred to as a photo interrupter) which detects the presence or absence of an object to be detected without contact.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIGS. 7 (a), (b), and (c) are a front view, a side view, and a front view of a light-receiving side primary mold body according to a conventional example, respectively.
FIG. 8 is a cross-sectional view showing a state in which both the primary and the secondary molds on the light emitting and receiving side and a slit plate are inserted into a secondary molding die according to the conventional example, and FIG. FIG.

A conventional photo interrupter is shown in FIG.
As shown in (c) to (c), the light-receiving chip 1 is mounted on the lead terminal 2, the light-receiving chip 1 is connected to another lead terminal 3 with a gold wire 4 and covered with a light-transmissive resin 5, and a light-receiving side primary molded body is formed. Is formed. At this time, the light-transmitting resin portion 5 is molded so that the upper surface of the light-receiving chip has a convex shape 5a. Similarly, a light emitting chip 6 is used in place of the light receiving chip 1 of the light receiving side primary mold body to form a light emitting side primary mold body.

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

[0005]

By the way, in the above-mentioned prior art, by shortening the length of the L portion, the width (slit) of the light passage is narrowed, and a photointerrupter with higher resolution can be obtained. As shown in FIG. 7, the corner of the portion 5a in FIG.
The portion L'contacting the next molding die 7 becomes smaller,
Since the dimension of L'is unstable because it is a resin molded product and may be 0 in an extreme case, it is difficult to stably mold L'to about 0.1 mm by this method.

Even if L'can be made small, in the secondary molding, since the L'part is pressed from the rear by 7a so as to come into contact with the mold 7, the 5a part is difficult to form in terms of strength. There was a problem called.

Therefore, in view of the above problems, an object of the present invention is to provide a method of manufacturing a photo interrupter, which has a simple manufacturing process and can surely secure a narrow slit width for narrowing an optical path.

[0008]

In order to achieve the above object, the present invention mounts a light emitting / receiving chip on each of 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 plurality of primary mold connecting bodies primary-molded with a light-transmitting resin, and a plurality of light-emitting surfaces and light-receiving surfaces of the both primary mold connecting bodies, at least on the light-receiving surface side, corresponding to the light-receiving and emitting chips. A slit plate connecting body in which a slit plate is connected to the common frame at the same pitch is overlapped, and 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 slit plate connecting body in which a plurality of metal slit plates corresponding to the light emitting and receiving chips are connected is superposed on a primary mold connecting body in which a plurality of light receiving and emitting chips are primary molded and connected, and then Secondary molding is performed so that both primary mold connecting bodies on the light receiving and emitting sides face each other, so the slit plate is easy to set, and the positional accuracy is accurate, and multiple photo interrupters can be formed in one step. Can be improved.

Further, since the slit plate is made of metal, the slit width can be narrowed and the photo interrupter having high resolution and high reliability without deformation can be obtained.

[0011]

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

FIGS. 1A, 1B and 1C respectively show
A front view, a side view, a plan view, FIG. 2A, FIG.
(C) is a front view, a side view, and a plan view of a slit plate that restricts the passage of light, respectively, and FIG. 3 is a state in which both primary mold bodies on the light receiving and emitting side and a slit plate are inserted into a secondary mold. 4 is a sectional view taken along the line AA ′ of FIG. 3, FIG. 5 is a perspective view of the photo interrupter according to the present embodiment, and FIG. 6 is a primary mold connecting body and a slit plate of the photo interrupter according to the present embodiment. It is a perspective view which shows the process of combining a connection body.

The same functional parts as those of the conventional example shown in FIGS. 7 to 9 are designated by the same symbols.

The manufacture of the photo interrupter according to the present embodiment is performed by connecting a plurality of photo interrupters as shown in FIG. 6, which will be described later. In FIGS. 1 to 5, a single photo interrupter will be described as an example.

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

Here, the surface 9a of the both translucent resin bodies, which is the passage of light, is flat. Further, 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 which is a metal plate and serves as a light passage.
The slit plate 10 with 0b is formed. The slit plate 10 has L-shaped portions 10a at both left and right ends, and a lead portion 10c for insert molding into a secondary molding die 11.
Is equipped with. The lead portion 10c is integrally connected at its tip end 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 of the translucent resin body.

Next, as shown in FIG. 6, the primary mold connecting body A and the slit plate connecting body B on the light receiving and emitting sides are positioned in the positioning holes 13a, 1 of the common frames 13, 14, respectively.
4a are overlapped so as to overlap each other, and in this state, they are inserted into the secondary mold 11 as shown in FIG. 3, and injection-molded with a thermoplastic light-shielding resin 12, for example, PPS (polyphenylene sulfide) to integrate them. (In FIG. 6, only one of the light emitting / receiving unit is shown).

Then, after injection molding, the secondary molding die 1
Release from 1 to obtain a photo interrupter as shown in FIG. At this time, the L-shaped portions 10 are provided on the left and right ends of the slit plate 10.
Since there is a, and as shown in FIG. 4, it is embedded in the light-shielding resin 12 of the L-shaped portion 10a, the slit plate 10 is not reliably engaged with the translucent resin body and separated from it.

As is clear from the above description, according to this embodiment, the slit width S can be reduced to 0.1 mm or less because the slit plate 10 for limiting the passage of light is made of metal. Can be as narrow as the thickness of the slit plate), and since the slit plate 10 has a frame shape with positioning holes, the slit plate 10 has a high positional accuracy with respect to the photo interrupter outer shape and has a high resolution (resolution of 0.1 mm or less). ) A photo interrupter is obtained. Furthermore, there is an advantage that many pieces can be molded at the same time, which leads to improvement in productivity.

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

[0022]

As described above, according to the present invention, each primary mold connecting body on the light receiving and emitting side and the slit plate connecting body made of metal are simultaneously connected in a multiple manner by a common frame supporting each. Since the next molding is performed, the slit plate can be easily set, the positional accuracy is accurate, and a plurality of photo interrupters can be formed at the same time, so that the production efficiency can be improved.

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

[Brief description of drawings]

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

2 (a), (b) and (c) are a front view, a side view and a plan view, respectively, of a slit plate of one embodiment of the present invention for limiting the passage of light.

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

FIG. 4 is a cross-sectional view taken along the line A-A ′ of FIG.

FIG. 5 is a perspective view of a photo interrupter according to an exemplary embodiment of the present invention.

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

7 (a), (b), and (c) are a front view, a side view, and a plan view, respectively, of a light-receiving-side primary mold body according to a conventional example.

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

FIG. 9 is an enlarged view of a protrusion for an optical path stop of a photo interrupter according to a conventional example.

[Explanation of symbols]

 1 Light-receiving chip 2, 3 Lead terminal 6 Light-emitting chip 9 Light-transmitting resin 10 Slit plate 11 Light-shielding resin 13, 14 Common frame A Primary mold connecting body B Slit plate connecting body

Claims (1)

[Claims] 1. A primary mold connection in which light receiving and emitting chips are mounted on a plurality of light emitting side lead terminals and a plurality of light receiving side lead terminals, which are connected to a common frame at the same pitch, and which is primary molded with a transparent resin. And a slit plate connection in which a plurality of slit plates corresponding to the light emitting and receiving chips are connected at the same pitch as the common frame on at least the light receiving surface side of the light emitting surface and the light receiving surface of both the primary mold connecting bodies. A method of manufacturing a transmissive photointerrupter, characterized in that the two primary mold connecting bodies including the slit plate connecting body are integrally secondarily molded with a light-shielding resin so as to face each other. .