JPS5831311A - Transmissive type optical coupling device - Google Patents

Abstract

PURPOSE:To obtain a small-sized and thin transmissive type optical coupling device where the use range is wide, by allowing bent tips of a pair of optical fibers to face to a detection object and arranging a light emitting element and a photodetector at the other ends. CONSTITUTION:A transmissive type optical coupling device consists of glass fibers 6 whose detecting ends are bent to face to a detection object, spherical lenses 12, metallic sleeves 7, a light emitting diode 8, a photo transistor TR 9, cases 10 where detecting parts are held, and connectors 11 where the light emitting diode 8 and the photo TR 9 are held, respectively. The variance of the quantity of light due to passage of the object 4 between glass fibers 6 facing to each other is detected. Consequently, the detection resolution is determined by the outside diameter of glass fibers, and the structure is small-sized and thin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical fiber and a transmission type optical coupling device using optical coupling using the optical fiber as an optical path. It is an object of the present invention to provide a transmission type optical coupling device that can easily detect an object by forming a shape and optically coupling a light emitting element and a light receiving element at the other end of each optical path.

Recently, optical sensors that have a light emitting element and a light receiving element facing each other have come to be used in various fields for the purpose of detecting objects.

・ Conventionally, as shown in Fig. 1, a light emitting element 1 and a light receiving element 2 are placed facing each other, and the object 4 is integrated into a case 3.
was detected. This detection method has the disadvantage that the size of the optical sensor is limited by the sizes of the light emitting element 1 and the light receiving element 2, and that it cannot be mounted in a narrow location. Further, the resolution is also limited by the size of the opening 6 formed in the case 3.

The present invention provides a transmission type optical coupling device for detecting an object that eliminates the disadvantages listed in -F and enables a small and thin shape. Hereinafter, the configuration of the transmission type optical coupling device of the present invention will be explained with reference to the drawings.

FIG. 2 shows an embodiment of the invention. The transmission type optical coupling device of the present invention is a separate type, in which a glass fiber 6 and a spherical lens 1 whose detection ends are formed in a predetermined shape and face each other.
2, a metal sleeve 7, a light emitting diode 8, a phototransistor 9, a case 1o for holding a detection end, and a connector 11 for holding a pixel element.

Such a transmission type optical coupling device can be installed in a narrow place or in a place with severe environmental conditions without being restricted by the light emitting and light receiving elements and their cases.

FIG. 3 is a diagram showing an integrated type transmission type optical coupling device according to another embodiment of the present invention, in which all components are housed in a case 1-00.

The transmission type optical coupling device of the present invention shown in FIGS. 2 and 3 is as follows:
It is constructed by placing glass fibers 6, which have been bent into a predetermined shape on the detection end side, facing each other, and optically coupling a light emitting diode 8 and a phototransistor 9 to the other end of the glass fibers. This detects the change in the amount of light caused by the object 4 passing between the glass fibers. Therefore, glass fiber 6
The detection resolution is determined by the outer diameter of the sensor, and its structure can be easily made smaller and thinner. Note that a spherical lens 1 attached to the tip of the glass fiber 6
2 is for condensing light and increasing the S/N ratio.

Since the transmission type optical coupling device of the present invention uses an optical fiber as the detection end, it has the feature that there is no danger even when it is used for detecting the level of liquid such as gasoline, which requires antifogging properties. It also has excellent effects in applications such as Furthermore, since optical fibers are used, there are few restrictions on the installation location, and it can be easily installed even in very narrow spaces.

Although the above explanation is an example in which a glass fiber is used as the fiber, it goes without saying that almost the same effect can be obtained by using a polyfiber or a multi-component quartz fiber.

As described above, the present invention can provide a transmission type optical coupling device that can be made smaller and thinner and can be used in a wider range of applications.

[Brief explanation of drawings]

FIG. 1 is a sectional view illustrating a conventional transmission type optical coupler, FIG. 2 is a sectional view illustrating the configuration of a transmission type optical coupler according to an embodiment of the present invention, and FIG. FIG. 7 is a cross-sectional view illustrating the configuration of the same device according to another embodiment of the present invention. 4...Detection object, 6...Opening part, 6.
...Glass fiber, 7...Metal sleeve, 8...Light emitting diode, 9...Phototransistor, 1o...Holding the detection end case, 11...connector for holding the element, 1
2... Spherical lens. Name of agent: Patent attorney Toshio Nakao and one other person
2fi 10 63

Claims (1)

[Claims] (1) Each of the first optical fiber forming the first optical path and the second optical fiber forming the second optical path is bent, and one end of each of the two optical fibers is bent. are opposed to each other with a predetermined interval, and a light emitting element is optically coupled to the other end of the first optical fiber, and a light receiving element is optically coupled to the other end of the second optical fiber. shaped optical coupling device. (2) First. 2. The transmissive optical coupling device according to claim 1, wherein the second optical fiber, the light emitting element, and the light receiving element are all housed in a single envelope. (3) First. 2. The transmissive optical coupling device according to claim 1, wherein only one end of each second optical fiber is housed in a single envelope. (4) The transmission type optical coupling device according to claim 1, wherein the optical fiber is a glass fiber. (→ The transmission type optical coupling device according to claim 1, characterized in that the optical fiber is a poly fiber. (6) The patent claims that a lens is attached to each end of the optical fiber. The transmissive optical coupling device according to item 1.