JPH078806U - Optical fiber coil - Google Patents

Abstract

(57) [Summary] [Purpose] Even if the winding tension is increased, the winding stress of each layer is not applied to the terminal portion at the beginning of winding. A hole reaching the inner peripheral surface is formed as a passage 21 at a winding start position 20 of an optical fiber 14 in a cylindrical body portion 12 of a bobbin 11, and a winding start end portion 14a of the optical fiber 14 is passed through the passage 21. Be outsourced to the outside.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an optical fiber coil which is used in a sensor portion of a ring interferometer such as an optical fiber gyro, in which an optical fiber is wound around a body of a bobbin one or more times and two or more layers are wound.

[0002]

[Prior art]

 FIG. 3 shows a conventional optical fiber coil of this type. The bobbin 11 has a collar 13 integrally formed with collars 13 on both outer peripheries of both ends, and two or more optical fibers 14 and one or more layers are wound around the outer periphery of the body 12 between the collars 13. And is used as the optical fiber coil 15. From the winding start end of the optical fiber 14, it is led out to the outside as a winding start terminal portion 14a along the radial direction from the position of the body portion 12 to the collar 13 which is in contact with this, and the winding start terminal portion 14a and the optical fiber 14 The winding end terminal portion 14b, that is, the end portion of the outermost layer of the optical fiber coil is used to connect to another portion.

[0003]

[Problems to be solved by the device]

 In order to shorten the manufacturing time of the optical fiber coil, it is necessary to increase the winding speed, and in order to avoid the mechanical resonance of the optical fiber itself which may cause a performance error in the vibration environment, the winding tension of the optical fiber Tends to increase. On the other hand, since the winding start terminal portion 14a of the optical fiber is pulled out from the lowermost layer to the outside along the inner surface of the brim, it is pulled out under the winding stress of each winding layer, and the stress is as described above. So tend to be stronger.

In the optical fiber coil, the state of the light propagating through the optical fiber 14 may be polarized light, non-polarized light, or the like. However, in the portion where the optical fiber receives an external force, the light propagates inside. It is widely known that the polarization state of the reflected light changes, and coupling occurs between two propagation modes with orthogonal polarization directions, which causes a large error when used in an optical fiber gyro. .

Further, there is a drawback that the loop 14 of the optical fiber coil is not neatly aligned because the end portion 14a at the start of winding the optical fiber is an obstacle, and the shape is disturbed.

[0006]

[Means for Solving the Problems]

 According to the first aspect of the present invention, the passage from the winding start position of the optical fiber to the outside is formed in the body of the bobbin, and the optical fiber winding start end is guided to the outside through the passage. According to the invention of claim 2, a passage is formed in the collar of the bobbin from the winding start position of the optical fiber to the outside, and the optical fiber winding start end portion is guided to the outside through the passage.

[0007]

【Example】

 FIG. 1 shows an embodiment of the invention of claim 1, and parts corresponding to those of FIG. 3 are designated by the same reference numerals. In this invention, a passage 21 is formed in the body portion 12 of the bobbin 21 'from the winding start position 20 of the optical fiber 14 to the outside. That is, the body 12 has a cylindrical shape, and a hole extending from the optical fiber winding start position 20 on the outer peripheral surface of the body 12 to the inner peripheral surface of the body 12 is formed as a passage 21. As the passage 21, the winding start terminal portion 14a passing through the passage 14a is not bent in the radial direction of the body 12, but is not bent suddenly at the winding start position 20 and is bent at an angle larger than 90 degrees. It is preferable to make it oblique to the peripheral surface of No. 2. The winding start terminal portion 14 is passed through this passage 21 and is led out to the outside, that is, from the inside of the body portion 12 to the outside.

FIG. 2 shows an embodiment of the invention of claim 2, and parts corresponding to those of FIG. 3 are designated by the same reference numerals. In this invention, a passage 22 is formed in the collar 13 from the winding start position 20 of the optical fiber 14 of the collar 13 to the outside. In this example, a hole is formed in the collar 13 as the passage 22, and the optical fiber winding start terminal portion 14a is passed through the passage 22 and led out to the outside. At this time, the passage 22 is formed along the direction opposite to the optical fiber winding direction so that the winding start terminal portion 14a is not strongly bent at the winding start position 20.

As a passage formed in the collar 13, as shown in FIG. 2C, a groove extending from the winding start position 20 to the outer peripheral edge of the collar 13 in the radial direction may be formed as the passage 23. The passage 21 may be formed substantially perpendicular to the peripheral surface of the body portion 12 in FIG. 1, and the passage 22 may be formed substantially perpendicular to the plate surface of the collar 13 in FIG.

[0010]

[Effect of device]

 As described above, according to the present invention, since the winding start terminal portion 14a is led out to the outside from the winding start position 20 through the passage formed in the body portion or the brim, the winding start terminal portion 14a is formed in each layer. Is not subject to wrapping stress and no coupling occurs between the two orthogonal propagation modes. In addition, the winding start end 14a does not get in the way when the multi-layer winding is performed, and the winding is performed in a clean shape.

[Brief description of drawings]

FIG. 1A is a longitudinal sectional view showing an embodiment of the invention of claim 1;
B is a diagram showing a cross section taken along the line AA, omitting the second or more layers of the optical fiber.

FIG. 2A is a vertical sectional view showing an embodiment of the invention of claim 2;
B is a front view showing the first turn of the optical fiber with the passage 22 part broken, and C is a perspective view showing a bobbin used in another embodiment of the invention.

FIG. 3A is a longitudinal sectional view showing a conventional optical fiber coil,
B is the front view.

Claims (2)

[Scope of utility model registration request] 1. An optical fiber coil in which an optical fiber is wound around a body of a bobbin one or more times, and two or more layers are superposed, and a passage leading from the winding start position of the optical fiber to the outside in the body. The optical fiber coil is characterized in that the winding start end portion of the optical fiber is led to the outside through the passage. 2. An optical fiber coil in which an optical fiber is wound around a body of a bobbin one or more times, and two or more layers are overlapped and wound, and a passage leading from a winding start position of the optical fiber to the outside is formed on the bobbin collar. An optical fiber coil, characterized in that it is formed in the optical fiber, and the winding start end portion of the optical fiber is led to the outside through the passage.