JPH0815331A - Light sensor - Google Patents

Abstract

(57) [Summary] [Structure] In an optical sensor comprising a polarizer, a quarter-wave plate, an electro-optic crystal element having a Pockels effect, and an analyzer, one electro-optic crystal element is provided for measuring a plurality of voltages. A plurality of transparent electrode films arranged side by side on the longitudinal side of the flexible substrate, a flexible substrate having an electrode at one end and a plurality of contact pieces at the other end, a plurality of contact pieces at the other end of the flexible substrate, and one end To the electrode of the flexible substrate and the other end extending to the contact piece and provided on the flexible substrate, and the conductive film is bonded to the transparent electrode of the electro-optic crystal element with a conductive adhesive. I am trying. [Effect] Even if there is a difference in the coefficient of thermal expansion between the electro-optical crystal element and the flexible substrate due to a change in ambient temperature, the electro-optical crystal element does not cause the hysteresis of the modulation degree and the line voltage and zero phase can be accurately obtained. It is possible to measure line information such as voltage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical sensor for measuring line information of a distribution line.

[0002]

2. Description of the Related Art In a conventional optical sensor, an airtight adapter 2 is attached to an outer wall of an airtight container 1 via an O-ring 3 as shown in FIG. An opening is provided at the center of the airtight adapter 2, and the transparent glass 4 covering the opening is pressed against the airtight adapter 2 by the restraining plate 6 via the O-ring 5 to close the opening. A transparent glass substrate 7 is attached to the airtight container side of the transparent glass 4, and an optical sensor 8 is fixed to the transparent glass substrate. Inside the airtight container, there is provided a voltage detection unit (not shown) to which the line voltage applied to the switching electrodes for opening and closing the line of the distribution line, zero-phase voltage, etc. are applied. Is connected to the terminal board 9 via a lead wire (not shown). This optical sensor is provided with a set of a polarizer 8a, a quarter-wave plate 8b, an electro-optic crystal element 8c, and an analyzer 8d arranged in parallel.
A plurality of transparent electrode films 8e for applying a voltage are provided in the longitudinal direction on both side surfaces of one electro-optical crystal element, and each transparent electrode film and the terminal plate 9 are connected by a lead wire 10 to form a pair of optical electrodes. A plurality of voltage sensors are configured in the component. 11 is a collimator lens, 12 is an optical fiber, 1
3 is a lens mount. The optical sensor configured as described above is an optical component including a set of a polarizer, a quarter-wave plate, an electro-optic crystal element, and an analyzer, and a plurality of lines such as three-phase line voltage and zero-phase voltage of a distribution line. Information can be measured. However, since the plurality of transparent electrode films provided on the electro-optical crystal element and the terminal plate are connected by the lead wires 11, respectively, the connecting work is complicated. Therefore, as shown in FIG. 3, a conductive film 14a having a printed wiring is provided on a flexible substrate 14 made of an insulating material, one end of this conductive film is provided with an electrode 14b connected to the voltage detecting portion, and the other end is provided at the other end. Polarizers 8a and 1
/ 4 wavelength plate 8b The transparent electrode films 8e provided on both side surfaces of the electro-optical crystal element 8c of the photosensor in which the electro-optical crystal element 8c and the analyzer 8d are arranged are integrally bonded along the longitudinal direction of the electro-optical crystal element. It is glued and connected.

However, since one flexible substrate is adhered and integrated in the longitudinal direction of the electro-optical crystal element, when the ambient temperature changes, the electro-optical crystal element has a difference in thermal expansion coefficient. The stress due to the difference in coefficient of thermal expansion was generated between the flexible substrate and the flexible substrate. Therefore, the modulation degree of the voltage sensor is changed, and the detection accuracy is lowered. FIG. 4 shows the characteristic of the modulation factor with respect to temperature. When the error of the modulation factor is plotted on the vertical axis and the temperature is plotted on the horizontal axis,
As shown by the line a, the degree of modulation has a characteristic having hysteresis, and it was not possible to measure the voltage with high accuracy under the environment where the ambient temperature changes. Therefore, it is an object of the present invention to measure the modulation degree of the voltage sensor with high accuracy without causing hysteresis even when the ambient temperature changes.

[0004]

In order to achieve the above-mentioned object, the present invention is an optical device comprising a polarizer, a quarter-wave plate, an electro-optical crystal element having the Pockels effect, and an analyzer, and capable of measuring a plurality of voltages. In the sensor, a plurality of transparent electrode films provided side by side on one side of the electro-optical crystal element in the longitudinal direction, a flexible substrate having an electrode at one end and a plurality of contact pieces at the other end, and the flexible substrate at one end A conductive film having the other end connected to the upper electrode and extending to the contact piece, and the conductive film of the contact piece is adhered to the transparent electrode of the electro-optic crystal element with a conductive adhesive. .

[0005]

By the above means, each contact piece of the flexible substrate is adhered to each transparent electrode film of the electro-optical crystal element, and even if the electro-optical crystal element expands in the longitudinal direction due to a change in ambient temperature, it is provided on the flexible substrate. Since the slits are expanded and no stress is applied in the longitudinal direction of the electro-optical crystal element, the voltage can be measured with high accuracy without causing hysteresis.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a main part of an optical voltage sensor of the present invention. The same parts as those in FIGS. 3 and 4 are designated by the same reference numerals, and detailed description thereof will be omitted. Reference numeral 15 is a flexible substrate made of an insulating material, and a plurality of independent contact pieces 15b are formed at the other end by providing a plurality of slits 15a in a direction perpendicular to the longitudinal direction of the electro-optic crystal element. is there. Reference numeral 15c is a conductive film printed on the flexible substrate 15 and the contact piece 15b, and has an electrode 15d at one end.
15e is a support. The flexible substrate 15 thus configured and the conductive film 15c of each contact piece 15b are bonded to the transparent electrode film 8e of each electro-optic crystal element 8c with a conductive adhesive. In the optical sensor configured as described above, the luminous flux emitted from the collimator lens 11 from the optical fiber 12 is an electric power generated by applying an output voltage from a voltage detection unit (not shown) to the polarizer 8a, the quarter-wave plate 8b, and the transparent electrode film 8e. The line information of the distribution line is measured by being transmitted from the optical fiber to the signal processing unit (not shown) through the optical crystal element 8c and the analyzer 8d and the collimator lens. Now, when the ambient temperature of the optical sensor changes, the electro-optical crystal element 8c and the flexible substrate 15 expand at different thermal expansion coefficients, but each transparent electrode film 8e of the electro-optical crystal element 8c is expanded.
The contact piece 15b of the flexible substrate adhered to is independent, and even if the electro-optical crystal element expands or contracts in the longitudinal direction, the slit 15a provided in the flexible substrate expands or narrows, and the electro-optical crystal element 8c. Does not generate large stress. A line b in FIG. 4 shows the degree of modulation with respect to the ambient temperature in the embodiment of the present invention, and the longitudinal stress of the electro-optic crystal element 8c is not applied even if the ambient temperature changes.

[0007]

As described above, according to the present invention, even if the ambient temperature changes and there is a difference in the coefficient of thermal expansion between the electro-optical crystal element and the flexible substrate, the electro-optical crystal element has a hysteresis of the modulation degree. It is possible to measure line information such as line voltage and zero-phase voltage with high accuracy without occurrence of noise.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a main part of an optical voltage sensor of the present invention.

FIG. 2 is a schematic diagram of a conventional optical voltage sensor.

FIG. 3 is a schematic diagram showing a main part of a conventional optical voltage sensor.

FIG. 4 is a characteristic diagram showing the degree of modulation with respect to temperature.

[Explanation of symbols]

 8 Optical sensor 8a Polarizer 8b Quarter wave plate 8c Electro-optic crystal element 8d Analyzer 8e Transparent electrode film 15 Flexible substrate 15a Slit 15b Contact piece 15c Conductive film 15d Electrode

Claims (1)

[Claims] 1. An optical sensor comprising a polarizer, a quarter-wave plate, an electro-optic crystal element having a Pockels effect, and an analyzer, wherein both sides of one electro-optic crystal element in the longitudinal direction are measured in an optical sensor capable of measuring a plurality of voltages. A plurality of transparent electrode films arranged side by side, a flexible substrate having an electrode at one end and a plurality of contact pieces at the other end, one end connected to the electrode on the flexible substrate and the other end extending to the contact piece An optical sensor comprising: a conductive film that is present, wherein the conductive film of the contact piece is bonded to a transparent electrode of an electro-optic crystal element with a conductive adhesive material.