JPH11204827A - Photo coupler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high relative position accuracy of a light emitting unit device and light receiving unit device positioned in a common frame by a shading resin forming die, and obtain a higher output than that of the conventional product by a collimated light flux against the focal distance variation as a reflection type photo coupler. SOLUTION: A photo coupler has a light emitting unit device 13 having an emitting optical system having a light emitting chip 11 which is mounted on a lead frame 12 and primarily molded with a transparent resin, and photo detecting unit device 16 having a photo detecting optical system having a photo detecting chip 14, which is mounted on the lead frame 12 and primarily molded with a transparent resin, the light emitting unit device 13 and photo detecting unit device 16 are disposed parallel on the same plane, it has a shading resin body 17 formed together by a second mold of a shading resin, the emitting optical system has a function for emitting a light emitted from the light emitting unit device 13 as approximately a collimated light, and the photo detecting optical system has a function for collecting reflected lights of the emitted light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical coupling device (photo interrupter) for detecting the presence or absence of an object to be detected on a passageway without contact, and more particularly to an optical system for emitting light and an optical system for receiving light of the optical coupling device. .

[0002]

2. Description of the Related Art FIG.
The top view is shown in FIG. In FIG. 4, the light emitting chip 5
1 is die-bonded and wire-bonded to the lead frame 52, and 1 is made of a translucent resin (epoxy resin or the like).
Next, the light emitting side device 53 is formed.

The light-receiving chip 54 is die-bonded and wire-bonded to a lead frame 55, and is first-molded with a light-transmitting resin (e.g., epoxy resin) to form a light-receiving-side single device 56.

The light emitting side device 53 and the light receiving side device 56 are arranged in parallel, and are integrally formed with a light shielding resin 57, thereby producing a reflection type optical coupling device. An outgoing light window 58 and a light receiving window 59 are provided as light paths.

The light emitted from the light emitting chip 51 is condensed by a lens body 53a formed on the light emitting side single device 53, passes through an emission light window 58, an object passage X, and is reflected by a prism body 60. Then, the detection system passes through the detection object passageway X again, passes through the light receiving window 59, the lens body 56a formed in the light receiving side unit device 56, and enters the light receiving chip 54. The outgoing light 61 is an outgoing light passing through the central axis, and the outgoing lights 62 and 63 are outgoing light off the central axis.

In FIG. 5, reference numeral 50 denotes an optical coupling device, reference numeral 52 denotes a lead frame, reference numeral 53a denotes a lens body formed on the light emitting side single device 53, reference numeral 55 denotes a lead frame, and reference numeral 56a denotes a lens body formed on the light receiving side single device 56. Reference numeral 58 denotes an emission light window, reference numeral 59 denotes a light reception window, and reference numeral 60 denotes a prism body. The area of the outgoing light window is represented by So, and the area of the light receiving window is represented by S.
When i is set, there is a relation of approximately So = Si.

FIG. 6 is a configuration diagram of a conventional optical coupling device applied to detection of the remaining amount of liquid. 6, 50 is an optical coupling device, 51 is a light emitting chip, 52 is a lead frame, 53a is a lens formed on the light emitting side single device 53, 54 is a light receiving chip, 55 is a lead frame, and 56a
Denotes a lens body formed on the light-receiving-side single device 56;
Denotes an emission light window, 59 denotes a light reception window, 64 denotes a container for containing the liquid Y, and 65 and 66 denote prism-shaped reflecting surfaces formed on the bottom surface of the container 64.

[0008]

However, the conventional optical coupling device has the following problems. In FIG. 6, the outgoing light 61a passing through the central axis of the light emitting chip 51 exits the lens body 53a and then strikes the reflecting surface 65, becomes reflected light 61b, and hits the next reflecting surface 66. The reflected light 61c passes through the central axis and enters the light receiving window 59. On the other hand, the outgoing light 62a off the center axis is reflected by the reflecting surface 65.
And the reflected light 62b becomes the next reflected surface 66 of the container.
Will fall off. Similarly, the outgoing light 63a off the central axis strikes the reflecting surface 65 and becomes reflected light 63b, which impinges on the next reflecting surface 66 of the container, but the reflected light leaves the light receiving window 59 and cannot enter. Becomes Therefore, it is difficult to accurately detect the remaining amount of liquid in the container 64,
In addition, since the emitted light is dispersed, the amount of reflected light is reduced, resulting in a decrease in detection sensitivity.

In addition, the positional relationship between the prism body 60 or the reflecting surfaces 65 and 66 which function as the prism body must be accurately arranged with respect to the optical coupling device 50. In the case where the prism body 60 and the reflecting surfaces 65 and 66 are movable, it is necessary to set a highly accurate positional relationship and a mechanism with high reproducibility. As a result, the cost of the mechanism of the detection system has been increased.

[0010]

An optical coupling device according to a first aspect of the present invention has an optical system for emitting light in which a light emitting chip mounted on a substrate or a lead frame is primarily molded with a transparent resin. The light emitting side single device and the light receiving chip mounted on the substrate or lead frame are
A light receiving side single device having a light receiving optical system molded next, the light emitting side single device and the light receiving side single device are arranged in parallel on the same surface side, and a secondary mold of a light shielding resin is used. The light-emitting optical system has a function of emitting light emitted from the light-emitting-side single device as a substantially parallel light beam, and the light-receiving optical system has a function of emitting the light. It has a function of condensing reflected light.

According to a second aspect of the present invention, in the optical coupling device, the outgoing light optical system of the light emitting side single device and the light receiving optical system of the light receiving side single device are formed by molding. It is a feature.

According to a third aspect of the present invention, in the optical coupling device, the light-shielding resin body has an emission light window and a light reception window, the area of the emission light window is S1, and the light reception window is provided. The area of S
When 2, the relationship S1> S2 is satisfied.

Further, in the optical coupling device according to a fourth aspect of the present invention, the outgoing light optical system of the light emitting side single device is constituted by a convex lens.

The optical coupling device according to claim 5 of the present invention is characterized in that the light emitting side single device and the light receiving side single device have substantially the same outer shape.

In the optical coupling device according to a sixth aspect of the present invention, the light-shielding resin body is made of a thermoplastic resin.

Further, in the optical coupling device according to a seventh aspect of the present invention, as the optical means for reflecting the light emitted from the single device on the light emitting side and guiding it to the single device on the light receiving side, a reflection type using a prism body is used. It is characterized by constituting a detection system.

[0017]

1 to 3 are views showing an optical coupling device according to an embodiment of the present invention. FIG. 1 (a) is a schematic sectional view, FIG. 1 (b) is a top view, FIG. FIG. 3 is an explanatory diagram of an optical coupling device constituting a reflection type detection system, and FIG. 3 is a configuration diagram of an optical coupling device of the present invention applied to detection of the remaining amount of liquid.

In FIG. 1 of the present invention, the light emitting chip 11
Are die-bonded and wire-bonded to the lead frame 12, are primarily molded with a translucent resin (a thermosetting resin such as an epoxy resin), and the light-emitting-side single device 1
3 is formed.

The light-receiving chip 14 is die-bonded and wire-bonded to the lead frame 15 and is primarily molded with a light-transmitting resin (a thermosetting resin such as an epoxy resin) to form a light-receiving-side single device 16. .

The light emitting side single device 13 and the light receiving side single device 16 are arranged in parallel, are packaged in a light shielding resin body 17 integrally formed by a secondary mold of the light shielding resin, and are provided with a reflection type optical coupling device. 10 are produced. Outgoing light window 1
8 and the light receiving window 19 serve as a light passage
Is provided.

In FIG. 1B, which is a top view of the present invention, 10 is an optical coupling device, 12 is a lead frame, and 13a
Is a lens body (convex lens) formed on the light emitting side single device 13, 15 is a lead frame, 16a is a lens body (convex lens) formed on the light receiving side single device 16, 18 is an emission light window, 19 is a light reception window , 20 are prism bodies. As shown in FIG. 1B, when the area of the exit light window is S1 and the area of the light reception window is S2, the relationship is S1> S2.

1 and 2, the light emitting side single device 13 and the light receiving side single device 16 are manufactured by an injection molding method using a mold, a transfer molding method, a casting method, or the like. If the optical system of the light emitting side single device 13 and the light receiving side single device 16 is made substantially the same optical system, and the light emitting chip or the light receiving chip has an optically equivalent positional relationship, the same mold is used.
The light emitting side single device 13 and the light receiving side single device 16 can be manufactured, and the light emitting side single device and the light receiving side single device can have substantially the same outer shape. Further, the same resin can be used as the mold resin. As a result, manufacturing methods and manufacturing costs are reduced,
It can standardize products and respond to mass production. At this time, in order to distinguish the light emitting side single device and the light receiving side single device, it is possible to apply a thin translucent coloring, or it is also possible to provide an identification mark on a part of the outer shape. .

In FIG. 1 and FIG. 2, an example of the external size of the optical coupling device of the present invention is as follows: length × width × height = (3 to 6 m
m) × (7 to 10 mm) × (3 to 6 mm),
The diameter of the emission light window 18 is about 1.1 to 1.8 mmφ,
The diameter of the light receiving window 19 is about 0.7 to 1.0 mmφ.

In FIG. 1 and FIG. 2, the light emitting chip 11 and the light receiving chip 14 are
However, instead of the lead frames 12 and 15, a substrate made of ceramics or resin can be used.

Further, in FIGS. 1 and 2, a thermoplastic resin is used as the resin of the light-shielding resin body 17. For example, polyphenylene sulfide (PPS),
One of thermoplastic resins such as polycarbonate (PC), polybutylene terephthalate (PBT), crystalline polymer, amorphous polymer, and liquid crystal polymer or a mixture thereof is used, and an indie molding method or a transfer molding method is used. Are used. The reason why the thermoplastic resin is used is that the resin molding temperature is low and the external shape can be accurately maintained. This is because the shape and area can be manufactured to the designed values.

FIG. 2 is an explanatory view of an optical coupling device constituting a reflection type detection system. In FIG. 2, the light emitted from the light emitting chip 11 is collimated by a lens body (optical system for emitted light) 13a formed on the light emitting side single device 13, and is emitted from the window 18 for emitted light. The light enters the prism body 20. The light beam reflected in the prism body 20 is condensed by a lens body (light receiving optical system) 16 a formed on the light receiving side unit device 16 via the light receiving window 19 and enters the light receiving chip 14.

At this time, since the light beam diameter of the outgoing light 21 reflected in the prism body 20 is larger than the diameter of the light receiving window 19, the relative positional relationship between the light emitting side device 13 and the prism body 20 is slightly Even if the displacement occurs, it is easy to obtain a high incident light amount. In the present invention, when the area of the emission light window is S1 and the area of the light reception window is S2, S1> S2
In a relationship.

FIG. 3 is a block diagram of the optical coupling device of the present invention applied to the detection of the remaining amount of liquid. 3, reference numeral 10 denotes an optical coupling device, reference numeral 12 denotes a lead frame, reference numeral 13a denotes a lens body formed on the light emitting side single device 13, reference numeral 15 denotes a lead frame, reference numeral 16a denotes a lens body formed on the light receiving side single device 16, and reference numeral 18 denotes a lens body. An emission light window, 19 is a light reception window, 24 is a container for holding the liquid Y, and 25 and 26 are prism-shaped reflection surfaces formed on the bottom surface of the container 24.

The outgoing light 30a passing through the central axis exits the lens body (optical system for outgoing light) 13a, passes through the outgoing light window 18, enters the reflection surface 25, becomes reflected light 30b, and becomes the next reflected light 30b. The light enters the reflection surface 26. The reflected light 30c passes through the central axis, enters the light receiving window 19, and is formed into a lens body (light receiving optical system).
The light is condensed by 16 a and is incident on the light receiving chip 14. On the other hand, the outgoing light 31a off the central axis exits the lens body 13a, passes through the outgoing light window 18, enters the reflecting surface 25, becomes reflected light 31b, and enters the next reflecting surface 26 of the container. The reflected light 31c enters the light receiving window 19, is collected by the lens body (light receiving optical system) 16a, and is
4 is incident. Similarly, the outgoing light 32 off the central axis also enters the reflection surfaces 25 and 26 and enters the light receiving chip 14.

A description will be given of an example of a parallel light beam of the optical system for emitted light. The distance between the optical coupling device 10 and the prisms 25 and 26 formed on the bottom surface of the container 24 containing the liquid Y is about 15 to 50 mm. Therefore, at a distance of about 30 to 100 mm, which is twice as long as that, the emitted light optics are such that the emitted light becomes a parallel light flux that hardly spreads (spreads about 1.0 to 1.5 times). The system is designed.

As described above, the optical system for emitting light is designed to emit the light emitted from the single device on the light emitting side as a substantially parallel light beam, so that the container 24 or the prism body 20 containing the liquid Y as the object to be detected. Even if the relative positional relationship between the optical coupling device 10 and the optical coupling device 10 is slightly shifted, it is easy to obtain highly accurate detection. In particular, even when the prism body 20 and the reflecting surfaces 25 and 26 are movable bodies, highly accurate detection can be obtained because the emitted light is substantially a parallel light beam.

[0032]

As described above, according to the optical coupling device of the first aspect of the present invention, a light emitting chip mounted on a substrate or a lead frame is first-molded with a light-transmitting resin to obtain an optical output light. A light-emitting-side single device having a light-receiving side device having a light-receiving optical system in which a light-receiving chip mounted on a substrate or a lead frame is primarily molded with a light-transmitting resin. And the light-receiving side single device are arranged in parallel on the same surface side, and have a light-shielding resin body integrally formed by a secondary mold of the light-shielding resin. It has a function of emitting light emitted from the device as a substantially parallel light beam, and the light receiving optical system has a function of condensing reflected light of the emitted light. Therefore, according to the first aspect of the present invention, since the positioning in the common housing is performed by the light-shielding resin body molding die, a device having a high relative positional accuracy between the light-emitting unit and the light-receiving unit can be used. Obtained
In addition, by forming a parallel light beam, a higher output can be obtained as a reflection type optical coupling device than a conventional structure even with respect to a change in focal length.

In the optical coupling device according to a second aspect of the present invention, the outgoing light optical system of the light emitting side single device and the light receiving optical system of the light receiving side single device are formed by molding. It is a feature. Therefore,
According to the second aspect of the present invention, the light emitting chip and the light receiving chip, which are packages of the light emitting chip and the light receiving chip, themselves have lens characteristics (optical system), thereby reducing the number of constituent members and cost. At the same time, and at the same time, by reducing the number of members, the accumulated mechanical error can be reduced.

Further, in the optical coupling device according to a third aspect of the present invention, the light-shielding resin body has an emission light window and a light reception window, the area of the emission light window is S1, and the light reception window is provided. The area of S
When 2, the relationship S1> S2 is satisfied. Therefore, according to the third aspect of the present invention,
A margin is obtained in the positional relationship between the optical coupling device and the reflection system (prism) by the area difference, so that the combination of the detection systems does not require a high degree of accuracy.

The optical coupling device according to a fourth aspect of the present invention is characterized in that the optical system for emitting light of the single device on the light emitting side is constituted by a convex lens. Therefore, according to the fourth aspect of the invention, the design of the optical system is facilitated, and the lens system can be formed by package molding.

The optical coupling device according to a fifth aspect of the present invention is characterized in that the light emitting side single device and the light receiving side single device have substantially the same outer shape. Therefore, according to the fifth aspect of the present invention, it is possible to reduce the manufacturing method and manufacturing cost, standardize products, and cope with mass production.

In the optical coupling device according to a sixth aspect of the present invention, the light-shielding resin body is made of a thermoplastic resin. Therefore, according to the invention of claim 6, it is possible to lower the resin molding temperature, reduce the thermal stress on the single device, and accurately maintain the external shape.

Further, in the optical coupling device according to a seventh aspect of the present invention, as the optical means for reflecting the light emitted from the light emitting side single device and guiding the light to the light receiving side single device, a reflection type using a prism body is used. It is characterized by constituting a detection system. Therefore, according to the invention described in claim 7,
As the detection system, an optical path is formed between the prism and the optical coupling device, so that a large output can be obtained as specularly reflected light.
Also, since there is a space between the prism and the optical coupling device,
In the application of the optical coupling device constituting the reflection type detection system,
High degree of freedom in relative arrangement between the prism and the optical coupling device.

[Brief description of the drawings]

FIG. 1 is a diagram of an optical coupling device according to an embodiment of the present invention, wherein (a) is a schematic cross-sectional view and (b) is a top view.

FIG. 2 is an explanatory diagram of an optical coupling device that constitutes a reflection type detection system by combining the optical coupling device according to an embodiment of the present invention with a prism body.

FIG. 3 is a configuration diagram when an optical coupling device according to an embodiment of the present invention is applied to detection of a remaining amount of liquid.

FIG. 4 is a configuration diagram of a conventional optical coupling device.

FIG. 5 is a top view of a conventional optical coupling device.

FIG. 6 is a configuration diagram when a conventional optical coupling device is applied to detection of a remaining amount of liquid.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Optical coupling device 11 Light emitting chip 12 Lead frame 13 Light emitting side single device 13a Lens body (optical system for emitting light) formed on light emitting side single device 13 14 Light receiving chip 15 Lead frame 16 Light receiving side single device 16a Light receiving side single device 16 Lens body (light receiving optical system) 17 Light shielding resin body 18 Outgoing light window 19 Light receiving window 20 Prism body 21 Outgoing light 24 Container for containing liquid Y to be detected 25 On bottom of container 24 The formed prism-shaped reflecting surface 26 The prism-shaped reflecting surface formed on the bottom surface of the container 24 30 Emitted light passing through the central axis 31 Emitted light off the central axis 32 Emitted light off the central axis S1 Emitted light window Area of S2 Area of light receiving window

Claims (7)

[Claims] A light emitting chip mounted on a substrate or a lead frame; and a light emitting side single device having an optical system for emitting light, in which a light emitting chip mounted on a substrate or a lead frame is primarily molded with a transparent resin. 1 with translucent resin
A light receiving side single device having a light receiving optical system molded next, the light emitting side single device and the light receiving side single device are arranged in parallel on the same surface side, and a secondary mold of a light shielding resin is used. The light-emitting optical system has a function of emitting light emitted from the light-emitting-side single device as a substantially parallel light beam, and the light-receiving optical system has a function of emitting the light. An optical coupling device having a function of condensing reflected light. 2. The optical coupling device according to claim 1, wherein the optical system for emitting light of the single device on the light emitting side and the optical system for light receiving of the single device on the light receiving side are formed by molding. Optical coupling device. 3. The optical coupling device according to claim 1, wherein the light-shielding resin body has an emission light window and a light reception window, the area of the emission light window is S1, and the area of the light reception window is S1. An optical coupling device, wherein when S2, S1> S2. 4. The optical coupling device according to claim 1, wherein the optical system for emitting light of the single device on the light emitting side comprises a convex lens. 5. The optical coupling device according to claim 1, wherein the light emitting side device and the light receiving side device have substantially the same outer shape. 6. The optical coupling device according to claim 1, wherein the light shielding resin body is made of a thermoplastic resin. 7. The optical coupling device according to claim 1, wherein a reflection type detection system using a prism body is used as an optical unit that reflects light emitted from the light emitting side single device and guides the light to the light receiving side single device. An optical coupling device, comprising: