JPS598441A - Photoelectric converter having resistance to water pressure - Google Patents

Abstract

PURPOSE:To make the size of a converter small and the weight light, by embedding a photoelectric converter in a protective container consisting of a pressuretight container and a through-mouthpiece by filling and curing of a resin, to form a distortion absorbing layer made of a flexible cushion member or a space around the converter. CONSTITUTION:The protective vessel of an optical fiber 6 is constituted with the pressuretight container 11 and the through-mouthpiece 10, a filling resin 13 is filled and cured in this protective container and the photoelectric converter incorporated in an auxiliary case 12 is embedded. An electric wire 9 is connected to the electrode 1 of the converter 8 through a through-hole 15 of the through- mouthpiece 10 and a coated optical fiber 6' is penetrated through the other through-hole 15. Further, a distortion absorbing layer 14 made of a space or a flexible cushion member is formed around the converter 8 storing the auxiliary container 2, and the assembling of the photoelectric conversion is made easy, and thereby making the photoelectric converter used under high water pressure compact and light weight.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention converts an optical signal from an optical fiber into an electric signal and extracts it from an electric wire. Alternatively, the present invention relates to a photoelectric converter that extracts an electric signal from an electric wire as an optical signal using an optical fiber, and particularly relates to a water-resistant photoelectric converter used under high water pressure in the deep sea.

Signal transmission methods using optical fibers (referred to as optical fiber transmission systems) are superior to transmission using conventional electric wires, as optical fibers are lightweight, have no noise due to induction, have low signal attenuation, and can transmit large-capacity signals. Because it has superior features compared to conventional methods, it is being used in various fields. In an optical fiber transmission system, a photoelectric converter is essential in configuring the system because the information signal generation mechanism (eg, ITV camera) and processing mechanism (eg, TV cathode ray tube or computer) handle electrical signals. For this reason, various types of photoelectric converters for optical fiber transmission systems have been developed and put into practical use, but all of them are designed to be used under normal environments such as normal pressure and room temperature. There was no such thing that could withstand use in the deep sea, and there was a strong desire to develop a water-resistant photoelectric converter that could be used in the deep sea, for example, when an optical fiber transmission system was used to transmit signals between a deep-sea exploration vessel and a mother ship.

The present invention was made in response to such a request, and is characterized by having a structure in which an ordinary photoelectric converter is embedded in a small and lightweight protective container by filling and solidifying resin, and is suitable for use under high water pressure in the deep sea. In order to withstand this, it is necessary to provide a space or a flexible cushioning layer around the photoelectric converter to absorb the strain caused by high water pressure.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

Figure 1 shows an example of the structure of a general photoelectric converter.
) In the 0/E unit, an electric signal input from a pair of electrodes (1) is converted into an optical signal by a light emitting diode chip (3) placed on a ceramic substrate (2), and then sent to a fixing metal fitting (4) and a sleeve (5). ) is incident on the end face of an optical fiber (6) fixed at a In the E10 unit shown in (b), the optical signal transmitted through the optical fiber (6) is radiated onto the photodiode chip (3), converted into an electric signal, and then the electrode (
1). The positional relationship between the end face of the fiber (6) and the diode chip (3) requires strict precision. For example, even when using the insertion method using the connector (7), there is requires a high degree of positioning accuracy. Fatal problems when using a photoelectric converter with such a configuration in the deep sea include poor insulation of the diode chip (3) and electrodes (1) caused by seawater, and the fact that the fixing metal fittings are damaged due to the strong water pressure of the deep sea. (4)
This causes distortion in the entire converter and changes the positional relationship between the end face of the optical fiber (6) and the diode chip (3), which deteriorates the coupling efficiency of light between the end face and the chip, making it no longer able to function normally. It is expected that if the water pressure increases further, it will be destroyed.

In order to solve this problem, the inventors devised a structure in which a photoelectric converter is housed in a metal protective container that has a base for passing optical fibers and electric wires through, and the inside of the protective container is filled and solidified with resin. After careful consideration, we decided to select a resin that has good adhesion to protective containers, optical fibers, electric wires, etc.
2. It has been confirmed that waterproofness is ensured even under deep sea conditions exceeding 200 m2, but in order to reduce the distortion that occurs in the photoelectric converter to the extent that it does not pose a problem in terms of transmission characteristics, it is necessary to use, for example, a stainless steel protective container, As a result of further development activities, we came to the conclusion that under a pressure of 200 to 9/an", which is equivalent to 200m, the container would need to have a wall thickness of 10m or more, making it heavy and large. Second
2 is a structural sectional view showing an embodiment of the present invention,
The optical fiber (6) is coated with a material such as nylon that has good adhesion to resin (6y), and the electric wire (9) is connected to the electrode (1) of the photoelectric converter (8). Enameled wire, nylon coated wire, etc. are also used, and each wire is guided to the outside via a through-cap σQ.01) is a cylindrical pressure-resistant container, and in this example, a protective container is formed with the through-cap aai. The internal auxiliary container sub-container is embedded in thermosetting resin α3 filled and solidified without any gaps. The auxiliary container μs forms a space or a strain absorbing layer 04) made of a flexible cushioning material around the photoelectric converter (8). In a water-resistant photoelectric converter with such a configuration, the protective container only needs to have enough strength not to be destroyed by the water pressure under the large water pressure of the deep sea, and since there is a strain absorbing layer of 0 brown, the internal strain is resistant to distortion due to water pressure. A major feature is that it does not have any effect on the photoelectric converter (8). Therefore, the wall thickness of the pressure-resistant container OB can be made much thinner than in the case where no strain absorption layer is provided, and the overall weight and size can be reduced.

It goes without saying that a cylindrical core to which stress is applied uniformly is best for the pressure-resistant container θ core, but if the material is a lightweight fiber-reinforced plastic with a high Young's modulus against compressive stress, such as carbon fiber or glass fiber, Compared to metal products, it is extremely desirable because it is lighter, has better corrosion resistance against seawater, and has better adhesion with the internal filling resin, resulting in a more stable structure. It is. The through-hole OQ of the penetration part is a part where water pressure is applied directly to the filled resin 03, and it is desirable that the inner surface of the through-hole OQ be designed to constructively improve the adhesive strength with the resin, and in the example, it is threaded. There is. The filling resin OJ is generally preferably a low-viscosity liquid resin such as a thermosetting epoxy resin, urethane resin, silicone resin, or unsaturated polyester resin. Also, as criteria for selection, it is desirable that the material of the protective container has a high adhesive strength with the optical fiber (6y or electric wire (9)).

The thickness of the strain-absorbing layer and the material are determined by the relationship between the strength of the protective container and the water depth in which it is used, and the space or strain having the thickness of the strain-absorbing layer (a device for measuring strain that occurs on the outer surface of the rack) A flexible cushioning material such as foamed plastic is selected that is thick enough to absorb the

The main role of the auxiliary container is to form and protect the strain absorption layer αΦ during resin filling, but if it is made of thin metal, it is a shielding layer for water vapor that passes through the fiber-reinforced plastic pressure container 09 and the filled resin 03. It also has the effect of working as a

I have explained the detailed structure above, but Deep Sea 2,
To introduce a specific example of a product designed with the assumption of use at 300m, a thin cylinder made of carbon fiber reinforced plastic with a thickness of 3B is used as a pressure-resistant container, and the water pressure test of 300m and 9/c+y+" and 1,000
A pressure cycle test (between 200 KP/c1n2 and normal pressure) was conducted twice, and it was confirmed that it had sufficient transmission characteristics in the deep sea of 2,000 m as designed.

In addition to the examples introduced above, other structural examples include integrating the pressure container and the through cap, making the entire body made of fiber-reinforced plastic, and housing the optical fiber and electric wire in one through hole. However, the key point of the present invention is to obtain waterproof property by embedding the photoelectric converter in a protective container by filling and solidifying resin, and furthermore, by providing a strain absorption layer around the photoelectric converter, it can be used in the powerful deep sea. Needless to say, the above-described structural examples are only one embodiment of the present invention in order to absorb the strain caused in the protective container by the water pressure.

The present invention is a lightweight and compact water-resistant photoelectric converter that can easily be used under strong water pressure, and is applicable to all types of photoelectric converters, which require assembly accuracy of several microns. This has the great advantage of being possible.

[Brief explanation of drawings]

Figure 1 shows an example of the structure of a general photoelectric converter, and (a) shows E1
0 unit, (b) is an 0/E unit, and FIG. 2 is a longitudinal sectional view showing an embodiment of the present invention. ■, ... Electrode 3, ... Diode chip 6, ... Optical fiber 8, ... Photoelectric converter Continued from page 1 0 Inventor Yutaka Hibino 1-1-3 Shimaya, Konohana-ku, Osaka-shi No. Sumitomo Electric Industries, Ltd., Osaka Works, Inventor: Kisso Sanbe, 1-1-3 Shimaya, Konohana-ku, Osaka City, Sumitomo Electric Industries, Ltd. 3 Sumitomo Electric Industries, Ltd., Kanto Works ■Applicant: Sumitomo Electric Industries, Ltd., 5-15 Kitahama, Higashi-ku, Osaka

Claims (2)

[Claims] (1) A structure in which a photoelectric converter is embedded in a protective container consisting of a pressure-resistant container part and a through-cap part by filling and assimilating resin, and strain is absorbed by a space or a flexible cushioning material around the photoelectric converter. A water pressure photoelectric converter characterized by having a layer. (2) The water-resistant photoelectric converter according to claim 1, wherein the entire or part of the protective container is made of fiber-reinforced plastic.