JPH025008A - Structure of optical coupler for fibergyro - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" This invention relates to the structure of an optical coupler for a fiber gyro.

Conventional technique (1r J As shown in Fig. 5, the intermediate parts of a pair of optical fibers l are connected to each other to form a thin rod-shaped combined part 2 and four pigtails 3, and the combined part 2 The optical coupling element 6 is formed by being fixed to the elongated first substrate 4-] with an adhesive or the like.

As shown in FIG. 6, the first substrate 4 of the optical coupling element 6 is inserted into the glass tube 7 and fixed with adhesive, and the pigtail 3 is led out from both ends of the glass tube 7, and both ends are fixed with adhesive or the like. The fiber optic coupler 8 is filled with the following.

As shown in FIG. 7, the conventional fiber gyro is attached to a disc-shaped fiber gyro 10F, which is wound around a thread-shaped hollow bobbin 11. A pair of support columns 13 facing each other with the center axis of the hollow cylinder in between are planted on the Shiloh heath 10, and the optical coupler 8 is mounted on the support columns 13, and is fixed with adhesive, for example. ．． Ru.

In addition, below the optical coupler 8, a fiber gyro member (light source, light detection 2), etc.) 14 or
Each pair of pictails 3 of the optical coupler 8 are straightened when they are drawn out from the glass tube 7, and then curved in the direction in which they are heard (not shown) or the bobbin 11. It spirally rises along the inner circumferential surface, is fixed to the inner circumferential surface with an adhesive, is led out from the opening of the bobbin 11, and is connected to a fiber coil or the like.

``Problem to be solved by invention'' The conventional optical coupler 8 has a structure in which the first substrate 4 is fixed in the glass tube 7 with adhesive, and then the pictails are fixed with adhesive at both ends of the glass tube 7. However, it was difficult to assemble, and it was expensive because it did not require a relatively large number of man-hours.

In addition, the key and standing odor of fiber shield 1'ζ is glued and fixed to the inner circumferential surface of the fiber bobbin by slowly bending it so that strong force is not applied to the pigtail that is drawn out from the crow N and causing it to become wired. However, due to the poor workability of the structure, the number of assembly steps required was high, leading to an increase in the cost of assembly and toilets.

The purpose of this invention is to make the optical coupler itself more economical and to improve its structure so that it can contribute to making the fiber gyro into which it is incorporated economical.

"Means for resolving the problem" In order to achieve the above object, in the present invention, the intermediate portions of a pair of optical fibers in the longitudinal direction are connected to each other to form a thin rod-shaped combined part, and the combined part is An optical fiber is led out from both parts of the fii to form a big tail, and the combined part is fixed on the elongated first substrate to constitute an optical coupling element, and the fiber of the fiber to be incorporated into the optical coupling element is assembled. The first substrate of one or more optical coupling elements is fixed to the center of a second substrate having an outer diameter slightly smaller than the inner diameter of the coil bobbin, and the pigtails of the optical coupling elements are An optical coupler for a fiber gyro is configured by being fixed along the outer periphery of the two substrates.

Preferably, the second substrate is provided with an accommodation groove for accommodating the first substrate.

Furthermore, it is desirable to provide the second substrate (-1) with an arcuate guide groove for guiding the pigtail.

"Example" Embodiments of the invention will be described with reference to the drawings.

FIG. 1A shows an optical coupler 8 of the present invention, in which the optical coupling element 6 (FIG. 5) described above is assembled into a disk-shaped device having an outer diameter slightly smaller than the inner diameter of the fiber coil bobbin of the fiber gyro. The second substrate (made of metal, ceramic, or synthetic resin) 11 is constructed with a real gL7-'C.

In the figure, the first substrate 4 is fixed along one diameter of the second substrate 11 at the center of the plate surface with an adhesive. First board 4
The pigtails 3 led out from both ends of the fiber are fixed to the board surface by adhesive 22 in the extending direction of the fiber joint, and at the same time, the two pigtails are separated from each other,
Each curved in the opposite direction, the second J! 5. It is bent along the periphery of the plate 21.1. One ζl adhesive 2 near both ends of the diameter of the second plate 11 perpendicular to the longitudinal direction of the first substrate 4;
Fixed by 3.

The one shown in FIG.
Similarly, this is an example in which the optical coupler 8 is mounted on a disk-shaped second substrate 21, and FIG. In this example, two optical coupling elements 6 are mounted apart from each other in the center of the plate surface along the major axis of the ellipse, and one pigtail at both ends of each optical coupling element 6 is connected to each other. This is the case. In all cases of FIGS. 1A, B, and C, the outer diameter of the 225th plate 21 is slightly smaller than the inner diameter of the fiber coil bobbin to be accommodated.

FIG. 2 shows a fiber gyro incorporating the optical coupler shown in FIG. It is formed.

FIG. 3 shows that an elongated rectangular accommodation groove 30 for accommodating the first substrate 4 of the optical coupling element 6 is provided in the second substrate 21 at the center of the plate opening, and a groove for guiding the pigtail 3 is provided. This shows an example in which an arcuate guide groove 31 is provided along the circumference. At both ends of the diameter perpendicular to the longitudinal direction of the first board accommodating groove 30 of the second board 21, a part of the periphery of the second board 21 is cut out, so that it is parallel to the longitudinal direction of the first board accommodating groove 11730. A pair of straight edges 32 are formed. Further, four fan-shaped portions 33 are formed extending from the short edge 30a of the first substrate accommodating groove 30 to the periphery of the second substrate 2. The depth a of the fan-shaped recess 33 is smaller than the depth b of the first substrate storage groove, for example, about 1/2 of b. The difference b-a between the two sweats is set equal to (2) depending on the thickness of the first substrate 4 to be accommodated. The pigtail guide groove 31 has a depth LJ equal to the depth a of the fan-shaped recess 33, and the straight edge 32 is closer to the end edge 33a of the fan-shaped recess 33.
It is formed along the periphery of the second substrate 21 in the direction +J.

FIG. 4 shows an optical coupler 8 constructed by mounting an optical coupling element 6 on the second plate 21 of FIG. The first substrate 4 of the optical coupling element 6 is fixed to the bottom surface of the first substrate accommodating groove 30 with an adhesive 34 . 1. The pigtails 3 led out from both ends of the 21A1-4 are extended into the fan-shaped recess 33 and fixed with adhesive 22, and the two pigtails 3 are bent in a direction away from each other and guided inside the pigtail guide groove. After being fixed inside the groove with adhesive 23, it is guided out of the groove from the straight edge 32 side.

Regarding the optical coupler shown in the first (zp, , c), the second
It is preferable that the substrate is suitably provided with a first substrate receiving groove and/or a pigtail guide groove as described above.

"Effects of the Invention" In the optical coupler of your invention, the optical coupling element can be fixed to the second JI plate instead of the conventional gaff tube, making assembly work easier, reducing assembly man-hours, and lowering costs. is possible.

Since the second substrate of the optical coupler can be easily attached to the inner circumferential surface of the fiber coil bobbin by, for example, a protrusion, there is no need for a conventional support column. Also, since the pigtail is led out of the board in the direction along the circumference of the second board,
It is convenient for raising the pigtail in a spiral shape along the inner circumferential surface of the fiber coil bobbin, and the working time can be shortened. As described above, the present invention not only makes the optical coupler more economical, but also reduces the number of parts and the number of assembly steps for the fiber gyro into which it is incorporated, thereby significantly contributing to making the fiber gyro more economical.

If a first substrate receiving groove is provided on the second substrate of the optical coupler (J), by adjusting the depth of the groove, the location where the first board surface and the fiber should be fixed with the adhesive 22 can be adjusted. Since the plate surfaces can be aligned on almost the same horizontal plane, that is, there are no steps, the fiber can be stretched in a straight line, making it easier to bond the pigtail with the adhesive 22.

In addition, since it is possible to bond without applying bending stress to the straight line portion, which is most sensitive to the influence of stress, the adhesive 22 can be easily peeled off from the substrate due to bending stress even if environmental conditions such as temperature change significantly. No force is generated, making it possible to bond with excellent environmental resistance.

When the second substrate is provided with a pigtail substrate groove, the pigtail can be more stably maintained against vibrations and shocks. In addition, it is easy to bend the pigtails led out from the first substrate to be similar to each other, and even if light loss occurs due to bending, the same amount is generated by the four pigtails, so it can be handled easily on an upper table.

The structure of the optical coupler of this invention has good consistency with the bobbin shape for the fiber gyro in terms of the pigtail lead-out method, the shape of the second board, etc., which leads to improved component mounting efficiency of the fiber gyro, and makes the fiber gyro smaller and lighter. You can also expect

[Brief explanation of the drawing]

1M is a plane showing the structure of the optical coupler for a fiber gyro of the present invention, and 2nd [15A and B are a plan view and A-A side cross section showing an example of a fiber gyro incorporating an optical coupler to the first circle, respectively. 3A, +3 and C are plan views showing modified embodiments of the second substrate 21 of FIG. 1A, respectively;
A-A side sectional view and 13-B side sectional view, Figures 4A and B
are a plan view and an A-A (!III sectional view) respectively showing an example of the optical coupler using the second substrate 21 in FIG. 61 is a plan view of a conventional optical coupler, FIGS. 7A and 13
+lj (Plan view and A-A side sectional view showing an example of a fiber gyro incorporating the optical coupler 8 shown in FIG. 6, respectively)
(be.

Claims (3)

[Claims] (1) The intermediate portions of a pair of optical fibers in the longitudinal direction are joined together to form a thin rod-shaped combined part, and the optical fibers are led out from both ends of the combined part to form a pigtail, and the combined part One or more pieces are fixed on the second substrate, which constitutes an optical coupling element, and which has an outer diameter slightly smaller than the inner diameter of the fiber coil bobbin of the fiber gyro in which the optical coupling element is to be incorporated. A structure of an optical coupler for a fiber gyro, wherein a first substrate of the optical coupling element is fixed, and a pigtail of the optical coupling element is fixed along the outer periphery of the second substrate. (2) The structure of the optical coupler for a fiber gyro according to claim (1), wherein an accommodation groove for accommodating the first substrate is formed in the second substrate. (3) Claim light (1) or (2) in which an arcuate guide groove for guiding the pigtail is formed on the second substrate.
Structure of the optical coupler for fiber gyro described.