JPH07280573A - Fiber optic gyro - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide a downsized optical fiber gyro. An optical fiber gyro according to the present invention comprises a light source, a light receiver for receiving a gyro signal, a coupler for splitting / combining light, a polarizer 11 as a polarization filter, a phase modulator 12 for modulating light, and a connecting portion of an optical fiber. And a bottom plate 18 on which optical components such as a canopy 17, an optical fiber sensing loop 10 and a polarizer 11 are mounted, and a circuit board integrated case 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber gyro, and more particularly to a miniaturized optical fiber gyro.

[0002]

2. Description of the Related Art The structure of a conventional optical fiber gyro will be described with reference to FIGS. The laser light emitted from the light source 7 is sent to the optical fiber sensing loop 10 as left-handed light and right-handed light via the optical coupler 6a, the polarizer 11 and the optical coupler 6b. The light propagating through the optical fiber sensing loop 10 is recombined by the optical coupler 6b and guided to the light receiver 8 via the polarizer 11 and the optical coupler 6b. Further, the circuit boards 2, 3 and 4 on which a signal processing circuit for obtaining a rotational angular velocity by processing a signal detected by the light receiver 8 and a circuit for driving the light source 7 are formed are, as shown in FIG. It was located above or beside Loop 10.

[0003]

While there is an increasing demand for miniaturization of optical fiber gyros, conventional optical fiber gyros have a problem in that the size of the optical fiber gyro becomes large due to the large number of parts in the case, and the structure becomes complicated. It was

[0004]

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a novel optical fiber gyro having a reduced size.

To this end, in the present invention, the laser light source, the optical fiber sensing loop, and the light emitted from the laser light source are branched and sent to the optical fiber sensing loop as left and right circular light, and propagated through the loop. An optical coupler that combines the returned light again, a photoreceiver that receives the combined light, a signal processing circuit that obtains a rotational angular velocity by processing the signals detected by the photoreceiver, and these are included together. In an optical fiber gyro including a case, an optical fiber gyro characterized in that a circuit board is integrated with the case is used.

The circuit board is a metal base circuit board in which an insulating layer such as Kapton (manufactured by DuPont) is provided on a metal base such as iron, aluminum and Invar, and an electric wiring path is formed by etching, printing and firing. can do.

[0007]

According to the present invention, since the circuit board also serves as a case, the number of parts can be reduced. Further, since the circuit board can be arranged in the space which was a dead space in the past, the size can be reduced.

[0008]

Embodiments of the present invention will be described with reference to FIGS.

[0009] As shown in FIGS. 1 and 2, the optical fiber gyro of the present invention, the light source 7, the light receiver 8 for receiving the gyro signal, the polarizer 11 couplers 6a, 6b, a polarizing filter for splitting and combining light , A phase modulator 12 that modulates light, a connection part protection component 9 that protects a connection part of an optical fiber, a canopy 17, an optical fiber sensing loop 10, and a polarizer 11.
It comprises a bottom plate 18 on which optical components such as the above are mounted, and a circuit board integrated case 16.

The circuit board integrated case 16 has a circuit board mounting component, that is, a resistor, a capacitor, and an I inside thereof.
An electronic circuit component 5 such as C, a transistor, etc. is mounted, and has a role of a circuit board having a circuit for driving the light source 7 or processing a signal, and a role of a case that collectively includes all the above-mentioned components.

The circuit board integrated case 16 is mounted on a metal base 19 made of iron, aluminum, Invar, etc., as shown in FIG.
A metal base circuit board on which an insulating layer 20 such as Kapton (manufactured by DuPont) and an electric wiring path 21 are formed can be used. In this case, the electric wiring path 21 is formed by etching, printing or firing, and the insulating layer 20 is formed by the metal base 1.
It adheres on 9 with a press or an adhesive agent.

Although the circuit board and the case are integrated in the above embodiment, the circuit board, the case and the bobbin of the optical fiber sensing loop 10 may be integrated.

[0013]

According to the present invention, since the circuit board also serves as a case, the number of parts can be reduced, the structure of the optical fiber gyro can be simplified, and the weight can be reduced. Further, since the circuit board can be arranged in the space which has been a dead space in the past, the size can be reduced, and further, the size and weight of the device equipped with the optical fiber gyro can be reduced.

[Brief description of drawings]

FIG. 1 is an AA cross sectional explanatory view showing an embodiment of an optical fiber gyro of the present invention.

FIG. 2 is a BB cross-sectional explanatory view showing an embodiment of the optical fiber gyro of the present invention.

FIG. 3 is a cross-sectional view showing an example of a circuit board integrated case used in the present invention.

FIG. 4A shows an example of a conventional optical fiber gyro
It is an A-section cross-section explanatory drawing.

FIG. 5B shows an example of a conventional optical fiber gyro.
It is a B cross section explanatory drawing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 case 2 circuit board A 3 circuit board B 4 circuit board C 5 electronic circuit component 6 coupler 7 light source 8 light receiver 9 connection part protection component 10 optical fiber sensing loop 11 polarizer 12 phase modulator 13 phase modulator drive signal lead Wire 14 Gyro signal lead wire 15 Circuit board connecting lead wire 16 Circuit board integrated case 17 Canopy 18 Bottom plate 19 Metal base 20 Insulating layer 21 Electric wiring path

Claims (2)

[Claims] 1. A laser light source, an optical fiber sensing loop, and the light emitted from the laser light source is branched and sent to the optical fiber sensing loop as left and right circular light, and the light propagating through the loop and returned is combined again. In an optical fiber gyro that includes an optical coupler, a photoreceiver that receives the combined light, a signal processing circuit that obtains a rotational angular velocity by processing the signals detected by the photoreceiver, and a case that includes them all together. An optical fiber gyro having a circuit board and a case integrated with each other. 2. The circuit board is a metal base circuit board in which an insulating layer is provided on a metal base, and electric wiring paths are formed on the insulating layer by etching, printing, or firing. The optical fiber gyro according to claim 1.