JPH0729651Y2 - Reflective optical coupling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a reflective optical device that detects the presence or absence of an object to be detected without contact.

<Prior Art> A conventional small-sized long-focus (focal length; about 4 m) reflective optical coupling device (hereinafter, simply referred to as reflective optical coupling device)
This will be described with reference to FIGS. 5 and 6.

FIG. 5 (a) is a plan view of a reflection type optical coupling device according to a conventional example, and FIG. 5 (b) is a sectional view taken along the line AA ′ of FIG. 5 (a).

As shown in FIGS. 5A and 5B, the conventional reflection type optical coupling device is separately mounted on the lead frame 1, and the gold wire 2
The light-emitting element 3 and the light-receiving element 4 which are internally connected to each other are covered with independent light-transmissive resin 5 to form a light-emitting side light-transmissive resin body and a light-receiving side light-transmissive resin body, respectively. The resin bodies are juxtaposed and integrally molded with the light-shielding resin 6 to form a reflection type optical coupling device 7 (without a lens), and a transparent lens case 8 is attached to the lensless reflection type optical coupling device 7. Was there.

FIG. 6 (a) is a diagram showing a distance between a conventional reflection type light rare-earth device and a detected object, and FIG. 6 (b) is a diagram showing a distance characteristic of a detection output of the conventional reflection type optical coupling device. .

In FIG. 6A, 9 is a reflection type optical coupling device, 10 is a detection object, and L is a distance between the reflection type optical coupling device 9 and the detection object 10.

In FIG. 6 (b), the horizontal axis represents the distance L between the reflection type optical coupling device and the detected object shown in FIG. 6 (a), and the vertical axis represents the detection output. In the figure, it is shown that the detection output of the reflection type optical coupling device becomes maximum at the focal length d.

<Problems to be Solved by the Invention> By the way, in the small-sized long-focus reflective optical coupling device having the conventional structure, since the transparent lens case 8 is attached to the lensless reflective optical coupling device 7, the overall appearance is large. Further, since the light emitted from the light emitting element 3 is reflected by the transparent lens case 8 and enters the light receiving element 4, there is a problem that some detection output appears even when there is no detection object.

Therefore, the purpose of the present invention is to have a smaller external structure than the conventional one,
Another object of the present invention is to provide a small-sized long-focus reflective optical coupling device that solves the conventional problem that some detection output appears even when there is no detected object.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides a light-emitting element and a light-receiving element mounted on a lead frame, each of which is primary-molded with an independent light-transmitting resin. Each of the upper surfaces of the body is formed as a convex lens having a vertical cross section outside the facing direction of the both elements, and the portions other than the upper surfaces of the both primary molded bodies are secondarily molded with a light-shielding exterior resin to form the light-emitting and It is characterized in that the primary moldings for receiving light are arranged side by side integrally.

<Function> Since the upper surfaces of both the light-emitting and light-receiving primary molded bodies are molded into convex lenses having a vertical section on the outer side in the facing direction of both the light-receiving and light-emitting elements, there is no need to attach a transparent lens case unlike the conventional case. The size in the height direction can be reduced. Further, it is possible to eliminate the conventional state in which the light from the light emitting element is reflected by the transparent lens case and is incident on the light receiving element, and the detection output appears even though there is no object to be detected.

Further, by providing the vertical cross section, the size in the horizontal direction can be reduced, and even if the vertical cross section is not provided, the optical path that does not contribute to the detection of the object to be detected is effectively used without waste due to the reflection of the plane of the vertical cross section. Since it can be used, the detection output is increased and the detection characteristics can be improved.

<Embodiment> An embodiment of the present invention will be described with reference to FIGS.

FIG. 1 (a) is a reflection type optical coupling device (hereinafter simply referred to as a reflection type optical coupling device) having a small long focal point according to an embodiment of the present invention.
FIG. 1 (b) is a sectional view taken along line BB ′ of FIG. 1 (a).

First, the light emitting element 12 and the light receiving element 13 are mounted on the lead frame 11, and internally connected by the gold wire 14, respectively. Next, the light receiving and emitting sides are separately covered with a light transmitting thermosetting resin 15 such as an epoxy resin to form a light emitting side light transmitting resin body 16 and a light receiving side light transmitting resin body 17 as primary moldings. Form.

At this time, the light-transmitting side transparent resin body 16 and the light-receiving side transparent resin body 17
Each of the upper surfaces is formed as a convex lens having a C-plane in a vertical cross section outside the light receiving elements 12 and 13 in the facing direction.

FIG. 2 is a cross-sectional view showing a cut of the primary molded body for forming the C-plane of the vertical section. The plane C of the vertical cross section is formed by removing the perspective portion D of the light emitting side light-transmitting resin body 16 from the light emitting side light-transmitting resin body 16 (similarly to the light receiving side light-transmitting resin body 17).

Next, in order to keep both the light-transmitting and light-receiving resin bodies at a constant interval, they are integrally molded by the light-shielding exterior resin 18 as a secondary molding to complete the reflection type optical coupling device of this embodiment.
Here, the light shielding exterior resin 18 may be a thermosetting resin such as an epoxy resin or a thermoplastic resin such as polyphenylene sulfide (PPS).

In addition, reference numeral 19 in the drawing denotes a light shielding wall provided so that light does not directly enter the light receiving element 13 from the light emitting element 12.

According to the structure of the reflection type optical coupling device according to the present embodiment as described above, since it is not necessary to attach the transparent lens case 8 as in the conventional case, the size in the device height direction can be reduced and the light emitted from the light emitting side can be reduced. It does not reflect on the transparent lens case 8 and enter the light receiving side, and no output appears when there is no detected object.

Further, as shown in FIG. 2, the lateral dimension can be reduced by cutting the light-transmitting side light-transmitting resin body 16 and the light-receiving side light-transmitting resin body 17 on the outer side in the facing direction of the light receiving and emitting elements.

FIG. 3 is a sectional view showing the optical path of the reflective optical coupling device according to this embodiment. As in the present embodiment, the vertical section C plane (hereinafter,
If there is a C surface), the light emitted from the light emitting element 12 is reflected by the C surface to take the optical path E, but if there is no C surface, the optical path E ′ is taken and does not affect the detection of the detection object 20. That is, by providing the C surface, the detected object 20 in the light emitted from the light emitting element 12
The effective light component for the detection of
The detection output on the 13 side can be increased and the detection characteristics can be improved.

Note that F is an optical path when passing through the curved surface portion.

FIG. 4 is a plan view of an example of a frame used when manufacturing the reflection type optical coupling device of this embodiment. As shown in the figure, if multiple frames are used, it is enough to cover and mold the lead frame with the light emitting / receiving elements twice, and it is easy to take multiple individual frames. A significant cost reduction is possible compared to the case where one transparent lens case is attached to each device.

<Effects of the Invention> As described above, according to the present invention, since the upper surfaces of both the light-emitting and light-receiving primary molded bodies are formed as convex lenses having vertical cross sections on the outer sides facing the light-receiving and light-emitting elements, respectively. It is possible to make the size significantly smaller than before, and it is possible to eliminate the conventional state in which light from the light emitting element is reflected by the transparent lens case and enters the light receiving element, and a detection output appears even when there is no object to be detected.

In addition, a higher detection output can be obtained and the detection characteristics can be improved as compared with the case where the vertical section is not provided.

Further, when the reflection type optical coupling device of the present invention is manufactured, by using the multiple frames, the cost can be significantly reduced as compared with the case of the conventional structure.

[Brief description of drawings]

FIG. 1 (a) is a plan view of a small-sized long-focus reflective optical coupling device according to an embodiment of the present invention, and FIG. 1 (b) is FIG. 1 (a).
2 is a cross-sectional view taken along the line BB ′ of FIG. 2, FIG. 2 is a cross-sectional view for explaining a cut portion of the primary molded body according to the same embodiment, and FIG. 3 is a small-sized long-focus reflective optical coupling device according to the same embodiment. FIG. 4 is a cross-sectional view for explaining the optical path, FIG. 4 is a plan view of an example of a frame used in manufacturing the small-sized long-focus reflective optical coupling device according to the same embodiment, and FIG. FIG. 5 (b) is a plan view of the reflection type optical coupling device of FIG.
6A is a cross-sectional view taken along the line AA, FIG. 6A is a view showing a distance between a conventional small-sized and long-focus reflected light coupling device and an object to be detected, FIG.
FIG. 6 is a diagram showing a distance characteristic of a detection output of a conventional small-sized long-focus reflection type optical coupling device. 11 ... Lead frame, 12 ... Light emitting element, 13 ... Light receiving element, 15
... translucent resin, 16 ... primary molded body, (light emitting side), 17 ... primary molded body (light receiving side), 18 ... light shielding exterior resin.

Claims (1)

[Scope of utility model registration request] 1. A light-emitting element and a light-receiving element mounted on a lead frame are primary-molded with independent translucent resin, respectively,
Each of the upper surfaces of the subsequent molded bodies is formed into a convex lens having a vertical cross section outside the opposing direction of the both elements, and the portions other than the upper surfaces of the primary molded bodies are secondarily molded with a light shielding exterior resin, A reflection type optical coupling device, characterized in that primary moldings for light emission and light reception are arranged side by side integrally.