JPH02236442A - Sensor structure for liquid type discrimination device - Google Patents

Abstract

PURPOSE:To improve the efficiency of emitting and receiving light and to accurately discriminate a liquid type by providing an optical fiber, a microlens and a reflecting mirror. CONSTITUTION:Signal light is supplied to the microlens 3 on a light emitting side from a light emitting unit through the optical fiber 2 and the signal light received by the microlens 6 on a light receiving side is connected to an operational amplifier and a discrimination circuit through the optical fiber 7. Then, the microlenses 3 and 6 abut on a glass plate 8 and they are integrated by a cylindrical body 9 together with the optical fibers 2 and 7. The cylindrical body 9 is inserted in a liquid feeding tube 10 and simultaneously constituted by being opposed to the reflecting mirror 5. Since the collimated beam of light is formed in such a way and the signal light is clearly caught by the lens having the improved efficiency of the emitting and receiving light, the effect of diffused external light is reduced and the liquid type is accurately discriminated. Besides, since the direction of the light can be changed by 180 deg., the structure of a sensor is miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sensor structure for a liquid type discrimination device such as oil type discrimination.

[Conventional technology]

Japanese Patent Laid-Open No. 64-31037 discloses technology for an oil type discrimination device that uses light as a signal transmission means and can safely distinguish the type of oil being fed without the risk of igniting the oil being fed. In the official bulletin,
A technique has been disclosed in which an optical fiber is extended from a light emitter and a light receiver, and the tip thereof faces oil in an oil pipe.

In this technology, in order to more accurately discriminate the liquid type, it is desired to improve the light transmission and reception efficiency and reduce the influence of ambient light, and it is also desired to reduce the space required for mounting. was.

[Problem to be solved by the invention]

The present invention has been made in response to the above-mentioned needs, and is intended to improve light transmission and reception efficiency, reduce the influence of ambient light, and more accurately discriminate liquid types, while also reducing the space required for mounting. be.

[Means to solve the problem]

The present invention aims to achieve the above-mentioned problems. It was done to
A pair of parallel optical fibers, a microlens attached to the tips of the optical fiber pair, and a 90-degree angle that changes the direction of the light sent out from one of the microlenses by 180 degrees and guides it to the other microlens. A sensor structure for a liquid type discriminating device is constituted by a reflecting mirror provided in a liquid to be discriminated having an internal angle.

[Effect]

According to the present invention, as described above, the light emitted from one of the microlenses attached to the tips of a pair of parallel optical fibers is redirected by 180 degrees by a reflecting mirror having an internal angle of 90 degrees, and Since the light is guided through the microlens, parallel light can be formed, improving light transmission and reception efficiency. Furthermore, since the signal light can be clearly captured by the microlens, the influence of disturbance light can be reduced, and the liquid type can be discriminated with higher accuracy. Furthermore, since the direction of the light can be changed by 180 degrees, the sensor structure can be made smaller.
It is possible to reduce the space required for mounting.

〔Example〕

FIG. 1 is a sectional view showing a sensor structure for a liquid type discrimination device according to the present invention.

The present invention will be explained based on FIG. company) 3.6, the light 4 sent out from the microlens 3 on the light sending side is 90
The direction of the light is changed by 180 degrees by a reflecting mirror 5 having an internal angle of 100 degrees, and the light is received by a microlens 6 on the light receiving side.

In the configuration shown in FIG. 1, signal light is supplied from a light emitter (not shown) to the microlens 3 on the light transmitting side via the optical fiber 2, and the signal light received by the microlens 6 on the light receiving side is It is connected to an operational amplifier, a discrimination circuit (not shown), etc. via an optical fiber 7.

Regarding the principle of liquid type discrimination, especially oil type discrimination, please refer to Japanese Patent Application Laid-Open No. 1986-
Since this is detailed in Japanese Patent No. 31037, it will be omitted here.

To explain in more detail with reference to FIG. 1, the microlens 3.6 is in contact with the glass plate 8 and is integrated with the optical fiber 2.7 by a cylindrical body 9 made of plastic. This cylindrical body 9 is configured to fit into the liquid feeding pipe IO and to face the reflecting mirror 5.

Since the sensor structure for a liquid type discriminator according to the present invention adopts the above configuration, parallel light can be formed, improving the light transmission and reception efficiency, and the signal light can be clearly captured by the microlens, reducing the influence of disturbance light. This allows for more accurate liquid type discrimination. Furthermore, the light is 180
Since the direction can be changed, the sensor structure can be made smaller and the mounting space can be reduced.

〔Effect of the invention〕

As explained above, according to the present invention, the light sent out from one of the microlenses attached to the tips of a pair of parallel optical fibers is turned 180 degrees by a reflecting mirror having an internal angle of 90 degrees. Since the signal light is transmitted to the other microlens and guided to the other microlens, a parallel line of light can be formed, which improves the light transmission and reception efficiency.Also, since the signal light can be clearly captured by the microlens, the influence of overselling can be reduced. This has the effect that species discrimination can be performed with higher accuracy. Furthermore, since the direction of the light can be changed by 180 degrees, the sensor structure can be made smaller and the mounting space can be reduced.

Note that the present invention is not limited to the above embodiments,
Of course, various modifications within the technical idea of the present invention are possible, such as using a plurality of optical fiber pairs or installing it in a location other than the liquid feeding pipe.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a sensor structure for a liquid type discrimination device according to the present invention. 2.7: Optical fiber, 3, 6,: Microlens, 5:
Reflector. Patent applicant Jun Kosha Co., Ltd.

Claims (1)

[Claims] (1) A pair of parallel optical fibers, a microlens attached to the tips of the pair of optical fibers, and the direction of the light sent out from one of the microlenses is changed by 180 degrees and guided to the other microlens. A sensor structure for a liquid type discrimination device comprising a reflecting mirror provided in a liquid to be discriminated having an internal angle of 90 degrees.