JPH06326349A - Photocoupler - Google Patents

Abstract

PURPOSE:To provide a photocoupler which can detect the position of an object to be detected in its longitudinal direction, can be reduced in cost and size, and can be easily changed in object detecting width and detecting pitch for detecting the presence/absence of the object in a passage in a non-contacting state. CONSTITUTION:In the photocoupler which detects the presence/absence of an object to be detected in a passage 21 in a non-contacting state, a light emitting element 24 and a plurality of light receiving elements 25a, 25b, and 25c are arranged in the same plane in the lower section of an enclosure and prism-like reflecting surfaces 26 and 27 are respectively provided above the elements 24 and 25a, 25b, and 25c. In addition, emission-side light transmission bodies 28 and 29 which use the space between the surfaces 26 and 27 as the passage 21 are provided and the bodies 28 and 29 form different optical paths 35a, 35b, and 35c against the elements 25a, 25b, and 25c, respectively.

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 (photointerrupter) for detecting the presence or absence of an object to be detected on a passage without contact, and more particularly to an optical coupling device with a connector.

[0002]

2. Description of the Related Art FIGS. 3A and 3B are views showing a structure of a conventional optical coupling device with a connector, wherein FIG. 3A is a vertical sectional view and FIG. 3B is a top view. FIG. 4 shows the internal wiring diagram.

The conventional optical coupling device includes the light emitting elements 1a and 1a.
b and 1c are mounted on the light emitting side lead frames 2, 2 and 2, respectively, and are electrically connected by a bonding wire 3 such as a gold wire, and these are respectively molded with a light transmissive resin to transmit light on the light emitting side. The resin bodies 4a, 4b, 4c are formed, and similarly, the light receiving elements 5a, 5b, 5c are mounted on the light receiving side lead frames 6, 6, 6 respectively, and the bonding wire 3
Are electrically connected to each other, and these are respectively molded with a light-transmitting resin to form light-receiving side light-transmitting resin bodies 7a, 7b, 7c, and both light-transmitting resin bodies 4a, 4b, 4c, 7a, 7
b and 7c are opposed to each other with the passage 8 in between, mounted on the printed circuit board 9, and the exterior case 10 made of a light-shielding resin.
Was stored in.

Here, the lead frames 2 and 6 are erected through the printed circuit board 9 and fixed with solder 11. Further, connector terminals 13a, 13b, 13c, 13d and 13e of a connector 12 for facilitating connection with an external device are fixed to one end of the printed circuit board 9 with solder 11 and electrically and mechanically. It is connected.

In the figure, 14a, 14b, 14c, 15
a, 15b, 15c are light passage windows (slits),
Reference numerals 16 and 17 denote condenser lenses, and 18a, 18b and 18
c is an optical path.

In the above optical coupling device, the light emitted from each of the light emitting elements 1a, 1b and 1c is collected by each condenser lens 1.
The light is condensed at 6, and each slit 14a, 14b, 14c,
After passing through the passage 8, each slit 15a, 15b, 15c and each condenser lens 17, each light receiving element 5a, 5b, 5c
Is incident on.

When the object to be detected moves in the passage 8 from the optical path 18a toward the optical path 18c, the optical paths are interrupted in the order of the optical path 18a, the optical path 18b, and the optical path 18c. Thereby, the light receiving elements 5a, 5b, 5c
In this order, the incidence of light is cut off, and the light receiving elements 5a, 5b, 5c
Current change occurs. This change in current makes it possible to detect the lateral position of the object to be detected in three stages.

[0008]

As shown in FIG. 3, in the conventional optical coupling device, three light emitting elements 1a, 1b, 1c and three light receiving elements 5a are provided in order to detect the position of the object to be detected in three stages. , 5b, 5c are used, each light receiving element 1a,
1b, 1c, 5a, 5b and 5c are respectively molded with a light-transmitting resin, and the light-emitting side light-transmitting resin bodies 4a, 4b and 4 are formed.
c, the light-receiving side light-transmissive resin bodies 7a, 7b, 7c are arranged, arranged in parallel in resin body units, and housed in the outer case 10. Therefore, it is difficult to downsize the optical coupling device structurally.

Further, the light emitting side lead frames 2, 2, 2 on which the light emitting elements 1a, 1b, 1c are mounted and the light receiving side lead frames 6, 6, 6 on which the light receiving elements 5a, 5b, 5c are mounted are respectively printed. Since it is necessary to stand upright on the substrate 9 and fix it with the solder 12, the manufacturing process is complicated and the cost is increased.

Further, conventionally, there has been no optical coupling device using a light guide to detect a position in the vertical direction.

In view of the above problems, the present invention is capable of detecting the vertical position of an object to be detected, achieving cost reduction and downsizing, and easily changing the detection width and detection pitch of the object. The purpose is to provide a coupling device.

[0012]

The optical coupling device of the present invention comprises:
In an optical coupling device for detecting the presence or absence of an object to be detected on a passage without contact, a light emitting element and a plurality of light receiving elements arranged flush with each other in the lower part of an outer case, and provided above each of the light emitting element and the light receiving element. And a light emitting side light guide and a light receiving side light guide having the passage between the reflection surfaces as the passage, and the light emitting side light guide and the light receiving side light guide. In the above passage, different optical paths are formed for the plurality of light receiving elements, respectively.

Further, in the optical coupling device according to claim 1, the reflecting surface is divided into a plurality of steps at each of the light emitting side light guide and the light receiving side light guide. Is.

[0014]

According to the above construction, the optical coupling device of the present invention can detect the position of the object to be detected in the vertical direction, and can guide light from a single light emitting element to a plurality of light receiving elements. Since the number of light emitting elements can be reduced, and the light emitting elements and the light receiving elements are provided in the same plane, the manufacturing process is simplified and the number of parts is reduced, and further, the light receiving elements can be arranged side by side in a chip size. The cost and size can be reduced.

In addition, it is possible to easily change the vertical detection width and the detection pitch of the object to be detected by changing the difference in level difference provided on the reflecting surface.

[0016]

1 is a vertical sectional view of an optical coupling device showing an embodiment of the present invention.

As shown in the figure, the transmission type optical coupling device with a connector (photointerrupter) of the present invention is for detecting the presence or absence of an object to be detected in the passage 21 without contact, and is provided at the bottom of the outer case 22. The light emitting element 24 and the light receiving elements 25a, 25 which are arranged flush with each other on the stored printed circuit board 23.
b, 25c, the light emitting element 24 and the light receiving element 25a,
25b and 25c are arranged above each other, prism-shaped reflecting surfaces 26 and 27 are formed on the upper surface, and the light emitting side light guiding body 28 and the light receiving side light guiding body having the passage 21 between the reflecting surfaces 26 and 27 are formed. And 29.

As the light emitting element 24, for example, an infrared light emitting diode is used, and the light receiving elements 25a, 25b, 2
For 5c, for example, a phototransistor for analog output is used, and these are die-bonded flush with the upper surface of the printed circuit board 23 directly by silver paste or the like. The light emitting element 24 is electrically connected by a boarding wire 35 such as a gold wire, and the periphery thereof is covered with a silicon resin 33 to protect the light emitting element 24. Further, the light receiving elements 25a, 25b, 25c are arranged at intervals, and after electrically connecting with the boarding wires 36, they are covered with the silicon resin 33.

A connector terminal 34 'of a connector 34 for facilitating connection with an external device is soldered to one end of the printed circuit board 23, and is housed in the lower part of the outer case 22.

The light emitting side light guide 28 is formed in a substantially rectangular parallelepiped shape using, for example, a transparent resin, and is arranged above the light emitting element 24. A lens 30 is formed on the lower surface of the light-emitting-side light guide 28 to collimate upward light emitted from the light-emitting element 24, and the lens 30 is formed on the upper surface.
45 so that the light that has become parallel light is reflected on the receiving side
A reflecting surface having a prism effect tilted at a degree is formed.

The light-receiving-side light guide body 29 is also formed in a substantially rectangular parallelepiped shape using a light-transmitting resin or the like.
It is arranged above a, 25b and 25c. The upper surface of the light-receiving-side light guide body 29 has a reflection surface 26 of the light-emitting-side light guide body 28.
The light reflected by the light receiving elements 25a, 25b, 2
A reflecting surface 27 having a prism effect inclined at 45 ° is formed so as to be incident on 5c, and is disposed at a position facing the light receiving elements 25a, 25b, 25c. In addition, V formed on the lower surface of the light receiving side light guide 29
The groove 37 is for surely separating the light incident on each of the light receiving elements 25a, 25b, 25c.

The outer case 22 is molded in advance using a light-shielding resin, and contains a light-emission-side storage section 38 for accommodating the light-emission-side light guide 28 and the light-reception-side light guide 29. The light receiving side storage portion 39 is formed in a substantially U shape in side view, and the passage 21 uses a space sandwiched between the light emitting side storage portion 38 and the light receiving side storage portion 39. In addition, a passage window (slit) 3 for transmitting and receiving light by allowing light-directing light to be provided between the light guides 28 and 29 on the opposing walls of the storage portions 38 and 39 that face each other across the passage 21.
1, 32 are formed.

In this way, both elements 24, 25a, 25
Since b and 25c are die-bonded to the printed circuit board 23 so as to be flush with each other, wire bonding and the like can be automatically performed in the same process, so that the manufacturing process can be simplified and the manufacturing cost can be reduced by automation. In addition, a single light emitting element 24
Light can be guided to a plurality of light receiving elements 25a, 25b, 25c, the lead frames 2, 6 and the like shown in FIG. 3 are not required, the number of parts can be reduced, and the manufacturing cost can be reduced. Further, the light emitting element 24 and the light receiving elements 25a, 25b, 25
Since c can be arranged in the chip size on the printed circuit board 23, the size can be reduced.

Next, the operation of the optical coupling device will be described.
Illumination light emitted upward from the light emitting element 24 is collimated by the lens 30 on the lower surface of the light emitting side light guide 28, and is totally reflected laterally by the reflecting surface 26 on the upper surface, and passes through the passage 31 from the slit 31. Is released to. Incidentally, 35a, 35b, 35c
Is the optical path.

Here, when there is no object to be detected on the passage 21 of the object, the light in the passage 21 enters the light guide 29 on the light receiving side through the slit 32, and is reflected downward by the reflecting surface 27. Totally reflected and the respective light receiving elements 25a, 25b, 25c
Is guided to.

On the other hand, when there is an object to be detected on the passage 21 of the object, for example, when the object to be detected moves downward from above the passage 21, the optical path 35a is interrupted first and the light receiving element 25a is reached. Of the light receiving element 25
A current change of a occurs. Further, when the object to be detected moves downward, the optical path is blocked in the order of the optical path 35b and the optical path 35c, a current change occurs in the order of the light receiving elements 25b and 25c, and the vertical position detection of the object to be detected is performed in three steps. Can be detected at.

FIG. 2 is a vertical sectional view showing another embodiment. Only the points of this embodiment different from the above embodiments will be described.

As shown in FIG. 2, in the optical coupling device of this embodiment, the reflecting surfaces 26 and 27 having the prism effect formed on the upper surfaces of the light guides 28 and 29 are divided into a plurality of reflecting portions. Faces 26a, 26b, 26c, 27a, 27b, 27c
It is composed of.

The reflecting surfaces 26a, 26b and 26c are inclined at 45 ° so as to totally reflect the light collimated by the lens 30 to the light receiving side, and divide the light into three lights. is there.

The reflecting surfaces 27a, 27b and 27c are arranged at positions facing each other so as to be paired with the light receiving elements 25a, 25b and 25c, respectively.
The light reflected by 26b and 26c receives light from the light receiving element 2 respectively.
It is tilted at 45 ° so as to totally reflect light to 5a, 25b and 25c.

By thus dividing the reflecting surfaces 26 and 27 by the steps, the difference between the steps can be changed to easily change the vertical detection width and the detection pitch of the object to be detected in the passage 21. can do. For example, reflective surface 2
6a, 26b and the reflecting surfaces 27a, 27b are made larger in level, that is, the reflecting surfaces 26 of both light guides 28, 29.
By extending the portions a and 27a in the vertical direction so as to project, the optical path 35a is set at a high position and the detection width is widened. Further, a desired pitch can be obtained by changing each pitch between the optical paths 35a, 35b and 35c by a step. Further, it is possible to increase the optical path by increasing the number of light receiving elements and reflecting surfaces.

Here, it goes without saying that the sizes of the slits 31 and 32 and the exterior case 22 can be changed to desired values by changing the difference in step.

Further, according to the above configuration, the light emitting side light guide 2
It is possible to reduce the thickness in the direction in which the reflecting surface 26 of No. 8 extends.

[0034]

As described above, according to the optical coupling device of the present invention, the position of the object to be detected can be detected in the vertical direction, and the cost and size can be reduced.

By changing the difference in level difference between the reflecting surfaces, it becomes possible to set the detection width and detection pitch of the object to be detected to desired values.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an optical coupling device showing an embodiment of the present invention.

FIG. 2 is a vertical sectional view of an optical coupling device showing another embodiment of the present invention.

3A and 3B are views showing a conventional example, FIG. 3A is a vertical sectional view, and FIG. 3B is a plan view.

FIG. 4 is an internal wiring diagram of the optical coupling device shown in FIG.

[Explanation of symbols]

21 Passage Path 22 Exterior Case 24 Light-Emitting Element 25a, 25b, 25c Light-Receiving Element 26, 26a, 26b, 26c, 27a, 27b, 27
c reflective surface 28 light emitting side light guide 29 light receiving side light guide 35a, 35b, 35c optical path

Claims (2)

[Claims] 1. An optical coupling device for contactlessly detecting the presence or absence of an object to be detected on a passage, a light emitting element and a plurality of light receiving elements arranged flush with each other in a lower portion of an outer case, the light emitting element and the light receiving element. A light emitting side light guide body and a light receiving side light guide body having a prism-shaped reflection surface formed on the upper surface thereof and having the passage between the reflection surfaces as the passage path. An optical coupling device, wherein the light-receiving side light guide forms a different optical path for each of the plurality of light-receiving elements in the passage. 2. The optical coupling device according to claim 1, wherein the reflecting surface is divided into a plurality of steps at each of the light emitting side light guide and the light receiving side light guide.