JPS584989A - Photo coupler - Google Patents

Abstract

PURPOSE:To operate the circuit of a light receiving element or a light emitting element sufficiently by positioning a synthetic-resin insulating layer among a photo-connector made of a metal, a receptacle and the light receiving element or the light emitting element. CONSTITUTION:The receptacle 1 of the photo-connector made of the metal, which consists of the receptacle 1 and a plug 2, and the light receiving element 4 are bonded while positioning the synthetic-resin insulating annular body 5 between the receptacle and the light receiving element. A section between the receptacle 1 and the element 4 may be insulated electrically by using an insulating paint layer in place of the annular body 5. When employing the photo- connector made of the metal, the function of the light receiving element or the light emitting element is frequently damaged remarkably on the operation of the circuits of these elements when the sheath section of the light receiving element or the light emitting element is made of the metal and the contactor pin of the P-N junction of these elements and a metallic sheath section are common. Accordingly, the circuits of these elements can be operated sufficiently by electrically insulating the photo-connector and these elements.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical coupling structure in a data link using optical fibers.

Since 1970, optical communication systems using optical fibers as transmission line media have been developed by successfully reducing the loss of the optical transmission characteristics of glass-based optical fibers. It has the characteristics of being able to transmit a large amount of information at a high transmission speed due to its long transmission time and wide band. Additionally, compared to coaxial wires, they have many advantages, such as being lighter, having a smaller cross-sectional area, being free from electromagnetic interference, and having less crosstalk. Optical fiber transmission always requires a light emitting part and a light receiving part, and a light emitting element and a light receiving element are used. However, coupling between the optical fiber and the light emitting element, and the coupling between the optical fiber and the light receiving element is an important issue. There is also a need for an optical coupling device that does not impair the function of the light receiving element and has less electromagnetic interference.

Conventionally, glass optical fibers have been used as the Optical 7 Eyer, but in this case, the diameter of the Optical 7 Eyer is extremely thin, less than 150 mm, and the connection between the fiber and the optical transmitting module and between the fiber and the optical receiving module is very small. High precision is required for the coupling part or the interconnection of fibers. Furthermore, glass-based optical fibers require a high degree of polishing and skill when processing the end face of the optical fiber. Furthermore, when used for short-distance information transmission, glass-based optical fibers have low bending resistance and are difficult to perform short-distance wiring work.

On the other hand, plastic optical fibers have a relatively thick core diameter compared to glass optical fibers, are easy to connect and process end faces, and have excellent bending resistance, making them suitable for short-distance transmission. Are suitable. We have developed a data link for visible light by using plastic optical fiber and developing a transmission module and a reception module that are compatible with it.

Because plastic optical fibers have a large core diameter, the required connection precision between fiber fibers or between fiber modules is not as strict as in the case of glass optical fibers, and plastic optical connectors that can be easily attached and detached have been proposed in the past. There is. However, plastic optical connectors have the problem of being susceptible to electromagnetic interference.

Furthermore, when using a metal optical connector, compared to a plastic optical coupler, it has the advantages of higher precision, being able to be attached and detached by hand, superior strength, and less electromagnetic interference. There is.

However, when a metal optical connector is used, the exterior part of the light receiving element or light emitting element is made of metal, and moreover, the terminal pin of the Pn junction of the light receiving element or light emitting element and the metal outer part are common II! I#C often significantly impairs the function of the light-receiving element or light-emitting element in terms of circuit operation. In other words, in many cases, in order to make full use of the function of the light-receiving element or light-emitting element, the terminal pin of the element and the power supply or This is because passive elements such as a #C resistor between ground and a capacitor are incorporated.

The inventors of the present invention made extensive studies to solve the above-mentioned problems, and as a result, they decided to use optical fibers.

When connecting the data link optical connector and the light receiving element or light emitting element, use metal as the optical connector to reduce electromagnetic interference. The present invention was achieved by discovering a method of electrically insulating an optical connector and a light receiving element or light emitting element so that the conduction of the element is eliminated and the circuit operation of the light receiving element or light emitting element is sufficiently performed.

That is, the present invention is characterized in that in 3.1 a data link source coupling device using an optical fiber, a synthetic resin insulating layer is interposed between the receptacle of the metal optical connector and the light receiving element or the light emitting element. The present invention provides an optical coupling device.

In the present invention, the metal optical connector may be made of any material as long as it is made of a material that contains a conductive metal element, such as an alloy such as brass or a conductive material that contains some insulators. It may be made of a metal material, preferably one that highly reduces electromagnetic interference, such as stainless steel or brass.

In the present invention, any synthetic resin insulating layer can be applied as long as it electrically insulates the optical connector and the light-receiving element or the light-emitting element. There is a method of forming it in the form of a paint layer.

1st #A and 2nd WJ are a partial sectional view and a perspective view of an example of an optical coupling device in which a synthetic resin insulating annular body of the present invention is interposed.

A synthetic resin insulating annular body (6) is interposed between the receptacle (1) and the light receiving element (4) of a metal optical connector consisting of a receptacle (1) and a plug e), and an adhesive (
6). The optical fiber (3) is plugged via a pipe (7).

The method using such an insulating annular body is easy, inexpensive, and can be carried out with relatively high accuracy.

Examples of the material of the insulating annular body include Bakelite, paper/
Examples include insulating materials such as epoxy resin, silicone resin, phenol resin, and fluororesin, or polyester, polymethylene, polycarbonate, and nylon. More preferably, epoxy resin, silicone resin, polyacetal resin, etc. are used in consideration of processability.

FIG. 1 is a partial cross-sectional view of an example of an optical coupling device in which an insulating paint layer of the present invention is interposed. A receptacle of a metal optical connector consisting of a receptacle (1) and a plug (2) (
1) and the light-receiving element (4) are bonded using an adhesive (6) with an ammonia layer (8) interposed therebetween. The insulating paint layer φ) is formed by applying a synthetic resin insulating paint to part or all of the metal optical connector and a portion of the scissor light receiving element to the extent that the performance of the light receiving element (4) is not impaired.

Examples of the synthetic resin insulation paint include epoxy-based, silicone-based, and unsaturated polyester-based insulation coatings. More preferably, it is convenient to use room temperature curing type JI8W-10. Although it is necessary to apply the coating uniformly, this method is also easy to implement, inexpensive, and effective.

Although FIGS. 1 to S show examples of coupling with a light-receiving element, coupling with a light-emitting element can also be carried out in exactly the same manner.

In addition to the methods described above, methods for forming a synthetic resin insulating layer include a method in which electrically insulating adhesive is injected into the empty space between a metal optical connector and a light-receiving element or a light-emitting element, and electrically insulating liquid is In short, any method can be adopted as long as it is possible to electrically isolate the metal connector and the photodetector, but in order to be industrially useful, it is simple and inexpensive. It is desirable that there be.

The effect of electrically insulating the optical connector and the light-receiving element or light-emitting element is particularly great for receiving modules that include a light-receiving element. This is because the current flowing through the photodetector in response to the amount of incident light is extremely small, and since data links often transmit five high-frequency waves, high-speed response is required. In particular, it is necessary to reduce stray capacitance as much as possible in the peripheral area of the light-receiving element.

In this sense, the electrical insulation effect between the optical connector and the light-receiving element or the light-emitting element is extremely large, and a dramatic improvement in the performance of the transmitting and receiving module in the data link is achieved.

As described above, the present invention is particularly useful for visible light data links #Cll1#C using plastic optical fibers; In this case, this fc@ is not specified.

[Brief explanation of the drawing]

Fig. 1 is a partial cross-sectional view of an example of an optical coupling device with a synthetic tree N insulating annular body interposed therebetween, and Fig. 2 shows a receptacle (1), a plug (2), and an optical fiber (3). ,(4)
(5) is a synthetic resin insulating annular body, (.) is an adhesive, (η is a pipe, and 忤) is an insulating paint layer. Valve lzonq. +2121 +3 days

Claims (1)

[Claims] t. An optical coupling device for a data link using an optical fiber, characterized in that a synthetic resin insulating layer is interposed between a receptacle of a metal optical connector and a light-receiving element or a light-emitting element. Device. 2. The optical coupling device according to claim 1, wherein the synthetic resin insulating layer is an insulating annular body. (v) The optical coupling device according to claim 1, wherein the synthetic resin insulating layer is an insulating paint layer.