JP3473349B2 - Information transmission system using optical fiber - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention applies ultrasonic vibrations corresponding to transmission information to an optical fiber, and transmits information by changing the polarization state of the optical fiber propagation light. The present invention relates to an information transmission system using an optical fiber, and more particularly to an information transmission system using an optical fiber that can supply power to an arbitrary place and does not require a solar cell or a battery. 2. Description of the Related Art Ultrasonic vibration is applied to an optical fiber by an ultrasonic transducer attached to the outside of an optical fiber cable to change the polarization state of light propagating in the optical fiber. An information transmission system has been devised which receives a transmission information of an ultrasonic vibration by analyzing a light receiving unit connected to a fiber (application by the present applicant, Japanese Patent Application No. 8-9948).
9 and Japanese Patent Application No. 8-77024). Thus, information can be transmitted from the middle portion of the optical fiber cable without cutting the optical fiber cable, and information can be transmitted from dispersed locations along the optical fiber cable. The configuration and operation of this system will be described with reference to FIG . The optical fibers of the optical fiber cable 2 include:
Light of a constant output is incident from a light source 1 connected to one end thereof. A light receiving section 6 is connected to the opposite end of the optical fiber. The light receiving unit 6 includes a polarization extraction element 61 having a function of extracting a specific polarization state such as a polarizer, and an APD (avalanche photodiode) installed at a subsequent stage.
And an optical / electrical conversion element (light receiver) 62 for outputting an electric signal corresponding to the change in the polarization state of the optical fiber propagation light. A spectrum analyzer 7 is connected to a stage subsequent to the light receiving unit 6, and the spectrum analyzer 7 can perform frequency analysis of an electric signal corresponding to a change in the polarization state of the optical fiber propagation light. On the other hand, a plurality of information input units 30 are provided in the middle of the optical fiber cable 2. Information input unit 3
0 is a frequency conversion unit 4 for converting transmission information into a frequency;
An ultrasonic vibrator 3 which is attached to the outside of the optical fiber cable and comprises an ultrasonic vibrator for applying transmission information converted into a frequency to the optical fiber, a solar cell for supplying power to the information input unit 30 and the information supply source And a power supply unit 5 composed of the above. Note that a temperature sensor, a rain gauge, or the like, which is an information supply source (not shown), is connected to the frequency conversion unit 4 as necessary. [0005] The transmission information such as temperature and rainfall converted into a frequency by the frequency conversion unit 4 causes an ultrasonic vibrator attached to the outside of the optical fiber cable 2 to operate at the frequency. Then, since a stress corresponding to the ultrasonic vibration is applied to the optical fiber, the polarization state of the optical fiber propagating light fluctuates according to the stress. In the light receiving section 6, the polarization extraction element 61
Passes only the light in the polarization direction of the polarizer, so that if the light incident on the light receiving unit 6 has a change in the polarization state, the light intensity of the transmitted light changes in accordance with the change in the polarization state. The electric signal converted by the optical / electrical conversion element 62 becomes an output corresponding to the polarization state fluctuation. By analyzing the electric signal with the spectrum analyzer 7, the information input by the information input unit 30 can be restored. In the prior art, since the power supply unit 5 is formed of a solar cell, power can be obtained even in a place where power cannot be supplied from the outside. Although there is an advantage that the unit 30 can be installed, there is a problem that the solar battery is expensive and that the power storage battery attached to the solar battery needs to be periodically replaced. It is an object of the present invention to solve the above-mentioned problems and to provide an information transmission system using an optical fiber which can supply power to an arbitrary place and does not require a solar cell or a battery. In order to achieve the above object, according to the present invention, an ultrasonic vibration corresponding to transmission information is applied to an optical fiber connected to a light source and connected to the optical fiber. by performing the frequency analysis of the polarization state variation of the optical fiber propagating light received by the photodetector, optical fiber to recover the transmitted information by applying ultrasound vibrations to the optical fiber
An information transmission system using the bus, optical fiber cable
Bull forming a composite cable in which complexed by twisting a pair of power supply lines, mounting an ultrasonic transducer to the optical fiber cable <br/> of the composite cable, the outer periphery of said pair of power supply line
The power supply units are shifted in the longitudinal direction.
The power supply section of
Connected to the power supply terminal and the power supply terminal
Power supply line connected to the vibrator and a pair supporting the power supply terminal
Of the power supply line.
Curved part and the straight part where the gripper contacts each other,
It is configured by bolts that penetrate and fix the wire portion . An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. As shown in FIG. 1, the information transmission system according to the present invention uses a composite cable 8 in which an electric wire is combined with an optical fiber, and the optical fiber portion of the composite cable 8 includes an ultrasonic transducer. The sonic vibration unit 3 is attached, and a power supply unit 9 for extracting power from the electric wire is attached to the electric wire portion of the composite cable 8. FIG. 2 shows the structure of the composite cable 8, and FIG.
The mounting structure of the power supply unit 9 is shown in FIG. A light source 1 is connected to one end of an optical fiber included in the composite cable 8, and a light receiving section 6 is connected to an opposite end of the optical fiber. The configurations of the light source 1, the light receiving unit 6, and the spectrum analyzer 7 are the same as those of the related art. An electric power supply (not shown) is connected to an electric wire (hereinafter, referred to as a power supply line) included in the composite cable 8. A plurality of information input units 30 are provided in the middle of the composite cable 8. The information input unit 30 includes a frequency conversion unit 4 similar to the related art and an ultrasonic vibration unit 3 having the mounting structure shown in FIG.
And a power supply unit 9 according to the present invention. Here, the composite cable will be described. As shown in FIG. 2, the composite cable 8 has a structure in which an optical fiber cable 81 and power supply lines 82 and 83 are twisted at a predetermined pitch in the longitudinal direction. The optical fiber cable 81 is housed in a space where the optical fiber core 811 is secured by the spacer 814, and the ultrasonic vibration is easily transmitted to the optical fiber core 811 around the optical fiber core 811. Jerry 812 is filled for the purpose. A tension member 813 made of steel wire or FRP is provided at the center. Water barrier 815 made of aluminum tape etc. on the outer periphery
And a sheath 816 made of vinyl or polyethylene. The power supply lines 82 and 83 are provided with insulating layers 822 and 832 made of vinyl or polyethylene and sheaths 823 and 833 made of vinyl or polyethylene around conductors 821 and 831 made of copper or aluminum. A positive voltage of a DC power supply is applied to the power supply line 82 and the power supply line 83
Is supplied with a negative voltage of a DC power supply. As shown in FIG. 3, an ultrasonic vibrator 3 attached to the composite cable includes an ultrasonic vibrator 31 and
And grippers 32 and 33 made of iron, stainless steel, or the like. The holding members 32 and 33 include a curved portion in contact with the outer periphery of the optical fiber cable 81 of the composite cable, and the holding members 3 and 33.
The linear parts 2 and 33 are in contact with each other, and are fixed by bolts (dashed lines in the figure) penetrating these linear parts. As the ultrasonic vibrator 31, a piezoelectric element or a magnetostrictive vibrator is used. The ultrasonic vibrator 31 includes grippers 32 and 33
It is fixed to the upper part of the straight part. Power supply unit 9 attached to composite cable
As shown in FIG. 4, a power supply terminal 91 made of copper, aluminum or iron, a power supply line 92 connected to the power supply terminal 91, and grippers 93 and 94 are provided. . The holding members 93 and 94 include a curved portion that contacts the outer circumference of the power lines 82 and 83 (only the power supply portion 9 of the power line 83 is shown) of the composite cable, and a straight line portion where the holding members 93 and 94 contact each other. Are fixed with bolts (dashed lines in the figure) penetrating these straight portions. Power supply terminal 91
Is used by penetrating the inside of the conductors 821 and 831 by penetrating the sharp ends from outside the power lines 82 and 83 to the sheaths 823 and 833 and the insulating layers 822 and 832. By using such a power supply unit 9, power can be supplied to an information supply source such as the ultrasonic transducer 31, a temperature sensor, and a rain gauge without disconnecting the power lines 82 and 83. After attaching the power supply unit 9 to the power supply lines 82 and 83, it is preferable to perform waterproofing processing by winding a waterproof tape as necessary. When the ultrasonic vibrating section 3 and the positive / negative power feeding section 9 are attached to the composite cable 8, the ultrasonic vibrating section 3 and the positive / negative power feeding section 9 are arranged in the longitudinal direction of the composite cable 8 so that they do not collide with each other. It is good to mount it slightly shifted. The information transmission system of the present invention operates in the same manner as the information transmission system of FIG. 5 with respect to the transmission of information, but forms a composite cable 8 composed of an optical fiber and an electric wire, and Since the power supply unit 9 is attached to the power lines 82 and 83 of the power supply unit 8 to supply power,
The power supply lines 82 and 83 can be supplied as they are, and the power supply unit 9 can be provided at an arbitrary place to supply power. In addition, since a solar cell or a battery is not required, the power supply lines can be inexpensively configured and periodically inspected and replaced. Maintenance work becomes unnecessary. In the above embodiment, the light source 1 and the light receiving section 6 are located on opposite sides of the optical fiber (composite cable 8), but the optical fiber core is connected to the composite cable 8 at the opposite end of the light source 1. The light receiving section 6 can be installed on the same side as the light source 1 by folding it back by connecting it to another housed optical fiber core. The information transmission system of the present invention is particularly effective when the information to be collected is distributed and arranged. The information transmission system collects information on rainfall, water level, precipitation, temperature, etc. along rivers and on roads. It is applicable to collecting weather information along. The present invention has the following excellent effects. (1) Power can be supplied while the power supply line is kept as it is, and a power supply unit is provided at an arbitrary place. (2) Since a solar cell or a battery is not required, the configuration can be made inexpensively and maintenance work such as periodic inspection and replacement is not required.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of an information transmission system according to an embodiment of the present invention. FIG. 2 is a structural view of a composite cable used in the present invention. FIG. 3 is a mounting structure diagram of an ultrasonic vibration unit used in the present invention. FIG. 4 is a mounting structure diagram of a power supply unit used in the present invention. FIG. 5 is a configuration diagram of a conventional information transmission system. [Description of Signs] 1 Light source 3 Ultrasonic vibrating unit 4 Frequency converting unit 6 Light receiving unit 7 Spectrum analyzer 8 Composite cable 9 Feeding unit 31 Ultrasonic vibrators 32, 33 Gripping tool 81 Optical fiber cables 82, 83 Power supply line 91 Power supply Terminal 93, 94 gripper

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G02B 6/00 G02B 6/44 G02B 26/00 H04Q 9/00 H04B 10/02

Claims (1)

(57) [Claims 1] Ultrasound vibration corresponding to transmission information is applied to an optical fiber connected to a light source, and the optical fiber propagates light received by a light receiver connected to the optical fiber. In an information transmission system using an optical fiber for restoring transmission information due to ultrasonic vibration applied to the optical fiber by performing frequency analysis of the polarization state fluctuation of light, an optical fiber cable
By twisting a pair of power supply lines to form a composite cable conjugated to a Buru, optical fiber cable of this composite cable
Attaching an ultrasonic vibrator to Le, the outer periphery of said pair of power supply line
The power supply units are shifted in the longitudinal direction.
The power supply section of
Connected to the power supply terminal and the power supply terminal
Power supply line connected to the vibrator and a pair supporting the power supply terminal
Of the power supply line.
Curved part and the straight part where the gripper contacts each other,
An information transmission system using an optical fiber , comprising a bolt that penetrates and fixes a wire portion .