JPH0248802Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a so-called liquid light guide in which a flexible tube member is filled with a transparent liquid having a refractive index greater than the refractive index of the tube member.

Generally, such a liquid light guide has a flexible tube member 1 sealed with a transparent liquid 2 having a refractive index greater than that of the tube member 1, as shown in FIG. Window members 3 and 4 having a refractive index larger than that of the tube member 1 are inserted into both ends of the tube member 1 to close both ends of the tube member 1. And light source 5
The light emitted from the tube member 1 enters one end of the liquid 2 sealed in the tube member 1 through one window member 3,
Total reflection is repeated at the interface between the inner surface of the tube member 1 and the sealed liquid 2, reaching the other end.
It is injected to the outside through the other window member 4.

By the way, in such a case, the tube member 1
When bent or the enclosed liquid 2
If the window members 3 and 4 expand, the window members 3 and 4 may fall out due to the internal pressure.

In order to prevent such problems, window members 3,
4 is projected from the end of the tube member 1,
A sleeve-shaped cap is attached over the protruding portions of the window members 3, 4 and the end of the tube member 1, and the cap is caulked to reduce the diameter of the window members 3, 4. There is one that is fixed to the tube member 1 to prevent it from coming off.

However, in the case where the cap is caulked as described above, a large amount of external force is applied to the window members 3 and 4 in order to maintain the seal through this caulking. There is a problem that 4 is damaged. Also, if the caulking is weak, there is a risk that the liquid 2 will leak.

The present invention was developed based on the above circumstances, and its purpose is to provide a liquid light guide that can reliably prevent the window member from slipping out and maintain reliable sealing.

The present invention will be explained below based on an embodiment shown in FIG. In the figure, 11 is a tube member. The tube member 11 is flexible, made of a material with a relatively low refractive index, and has a hollow tubular shape. A transparent liquid 12 such as degassed water is sealed inside the tube member 11, and the refractive index of this liquid 12 is larger than the refractive index of the tube member 11. A window member 13 is provided at the end of the tube member 11.
is inserted. This window member 13 is formed of a transparent material having a refractive index greater than the refractive index of the tube member 11, such as quartz or glass material,
It has a cylindrical shape. The window member 13 is tightly fitted into the end of the tube member 11 and closes the end of the tube member 11 in a liquid-tight manner. In this case, a portion of this window member 13 protrudes from the end of the tube member 11. A sleeve-shaped base 14 is attached to the end of the tube member 11. The cap 14 is made of a metal material or the like, and has a tube fitting portion 14a having an inner diameter that fits on the outer circumferential surface of the tube member 11 and a window member fitting portion 14a that has an inner diameter that fits on the outer circumferential surface of the window member 13. The tube fitting portion 14a is fitted to the outer periphery of the end of the tube member 11, and the window member fitting portion 14b is fitted to the outer periphery of the protruding portion of the window member 13. An adhesive 15 is interposed between the outer peripheral surface of the window member 13 and the inner surface of the window member fitting portion 14b of the base 14, and the adhesive 15 seals and fixes both. Note that the adhesive 15 used has a refractive index smaller than that of the window member 13. Further, an adhesive 15' is also interposed between the inner surface of the tube fitting part 14a of the cap 14 and the outer peripheral surface of the end of the tube member 11, and the adhesive 15' allows the cap 14 and the tube member 11 to be bonded together. The ends are fixed. In addition, this adhesive 1
5' may be the same as the adhesive 15 described above, or may be a different adhesive.

In the first embodiment of the present invention constructed as described above, the window member 13 and the tube member 11 are integrally fixed via the base 14 and the adhesives 15 and 15', so that the inside of the tube member 11 is Even if the pressure becomes high, the window member 13 will not fall out. Further, since the adhesive 15 interposed between the outer peripheral surface of the window member 13 and the window member fitting portion 14b of the base 14 has a refractive index smaller than that of the window member 13, this portion However, since the incident light is totally reflected, there is no loss of light.

Further, FIG. 3 shows a second embodiment of the present invention.
This second embodiment is based on the tube fitting portion 14 of the base 14.
The tube member 11 is clamped between the tube member 11 and the window member 13 by reducing the diameter of the tip edge of the tube member a, thereby further preventing the window member 13 from slipping out.

The second embodiment has the same structure as the first embodiment except for the above-mentioned points, and the parts in FIG. 3 that correspond to those in FIG.

As described above, the present invention involves fitting a window member into the end of a tube member, protruding a part of the window member, and providing a cap that fits around the outer periphery of the protruding portion of the window member and the outer periphery of the end of the tube member. , the cap, the window member, and the tube member are hermetically fixed with an adhesive. Therefore, even if the tube member is bent or the sealed liquid expands and the pressure within the tube member increases, the window member will not come out. Moreover, since the cap is bonded to the window member and tube member using adhesive, there is no need to tightly fit the cap to the window member and tube member, and no large external force is applied to the window member during bonding. There is no damage to the window member.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram illustrating the structure of a conventional liquid light guide, Fig. 2 is a longitudinal cross-sectional view of the main part of the first embodiment of the present invention, and Fig. 3 is a longitudinal cross-section of the main part of the second embodiment. It is a diagram. 11...Tube member, 12...Liquid, 13...
...window member, 14...cap, 14a...tube fitting part, 14b...window member fitting part, 15, 15'...
…glue.

Claims (1)

[Scope of utility model registration request] A flexible tube member, a transparent liquid sealed in the tube member, and a window made of a transparent material that is fitted into both ends of the tube member and partially protrudes from the end of the tube member. and a cap that fits onto the outer periphery of both ends of the tube member and the outer periphery of the window member at a portion protruding from the end of the tube member to prevent the window member from coming off at the end of the tube member. , an adhesive having a refractive index smaller than the refractive index of the window member is interposed between the inner surface of the cap and the outer peripheral surface of the protruding portion of the window member to seal and fix the window member and the cap; A liquid light guide characterized in that an adhesive is also interposed between an inner surface and an outer circumferential surface of an end portion of the tube member to seal and fix the tube member and the base.