JPH07198969A - Semiconduit fiber bundle and its production - Google Patents

Abstract

PURPOSE:To improve the resistance of a semiconduit fiber bundle without increasing its outside diameter. CONSTITUTION:This semiconduit fiber bundle 10 is formed by arraying many pieces of optical fibers and fusing and integrating these fibers, then forming the prescribed length of a part where bending is required as a flexible part 11, the required part on one side to exist in the part to be inserted at the time of building into a hard mirror as a hard part 12 and the other part as a hard part 13 at a short length. Vapor deposited films 14 for adding the resistance are formed at both ends of these hard parts 12, 13. Adhesives, etc., for reinforcement are inserted at the boundaries between the hard parts 12, 13 and the flexible part 11. A thin film-like coating layer 15 is formed on the outer periphery of the hard part 12. The coating layer 15 consists of a material to be deposited by evaporation, such as UV curing type resin, thermosetting type resin or glass for vapor deposition. A metallic mouthpiece 16 is fixed to the hard part 13. The flexible part 11 is circumferentially coated with a protective tube 17 having flexibility, such as silicone tube.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semi-conduit fiber bundle and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a rigid endoscope is linearly formed from an insertion portion to an eyepiece portion, and a relay lens optical system is used as an image transmission optical system therein. Recently, in order to make the image transmission optical system thinner and to make the outer diameter of the rigid mirror smaller, a large number of optical fibers are fused and integrated as an image transmission optical system, and a conduit-type image fiber that is not flexible is used. Has been used. On the other hand, as shown in FIG. 16, in the rigid endoscope 1, there is also a type in which the insertion portion 2 is made linearly rigid and the eyepiece 3 is provided on the proximal side so as to be inclined to the insertion portion. In the case of such a rigid endoscope 1, the image transmission optical system also has to be bent inside. Therefore, in the relay lens optical system, a direction changing optical system such as a prism is used on the hand side. Further, in the case of the image fiber bundle, the flexible fiber bundle 4 is used to cope with the inclination of the eyepiece 3.

[0003]

However, when the optical path is bent as described above, the outer diameter of the rigid mirror becomes large in the relay lens optical system, and the position adjustment at the time of assembly becomes a difficult work. Further, in the image fiber bundle, since the outer circumference is covered with a silicon tube in order to protect the discrete optical fibers for giving flexibility, it becomes thick, and the outer diameter of the insertion portion of the rigid endoscope also becomes large. Here, if the outer diameter is constant, the number of optical fibers must be reduced, and the effective pixel diameter becomes small.
Furthermore, it is possible to use a conduit type image fiber bundle that is fused and integrated and is not flexible, but if acid-eluting glass remains in the conduit part, it will be attacked by moisture in the air and will be resistant. Is weakened, and it is easy to break due to strong external force.

The present invention has been made in view of the above-mentioned problems, and provides a semi-conduit fiber bundle excellent in durability without increasing the outer diameter and a method for easily manufacturing the fiber bundle. The purpose is to

[0005]

The semi-conduit fiber bundle of the present invention comprises a core glass having a relatively high refractive index, a coated glass having a relatively low refractive index which covers the core glass, and further coated on the outside thereof. A triple optical fiber made of acid-eluting glass is aligned and fused to form a hard part, a predetermined part of the hard part is made a flexible part, and a coating thin film layer is formed on the outer periphery of the remaining hard part. is there.

In the method for manufacturing a semi-conduit fiber bundle according to the present invention, the coating thin film layer is formed by coating a resin on the outer periphery and hardening the same before forming the flexible portion from the child conduit, or by depositing a vapor deposition material. After the formation, the covering thin film layer corresponding to the flexible portion is removed, and then the flexible portion is formed by the acid elution method. Further, regarding the removal of the coating thin film layer of the flexible portion, the heat-resistant tape may be removed by coating the portion with a heat-resistant tape in advance and then depositing a vapor deposition substance.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 illustrates a semiconduit fiber bundle 10 of the present invention.
FIG. Here, the semi-conduit fiber bundle refers to an image fiber bundle that is mostly rigid and partially flexible. In the semi-conduit fiber bundle, a large number of optical fibers 24 as shown in FIG. 2 are aligned and fused and integrated, and then a predetermined length of a portion required to be bent is made into a flexible portion 11 to form a rigid mirror. A predetermined portion on one side located in the insertion portion when assembled is a rigid portion 12, and the other end portion is also a rigid portion 13 having a short length. Flexible part 11 is 1 / of the total length
It is about 3 or less. A vapor-deposited film 14 for adding resistance is formed at both ends of the hard portions 12 and 13, and an adhesive or the like for reinforcement is inserted at the boundary between the hard portion and the flexible portion to form the reinforcing layer 18. Is forming. Further, a thin film-shaped coating layer 15 is formed on the outer periphery of the hard portion 12. This coating layer 1
Reference numeral 5 is made of a vapor deposition material such as an ultraviolet curable resin, a thermosetting resin, and vapor deposited glass. A metal base 16 is fixed to the rigid portion 13, and a flexible protective tube 17 such as a silicon tube is coated around the flexible portion 11. The base may be fixed by covering the end of the rigid portion 12 for fixing the position, and the flexible portion 11 may not be covered with the protective tube 17.

According to this semi-conduit fiber bundle 10, the outer diameter of the hard portion can be reduced, and it is not easily broken by being attacked by moisture in the air and the durability is improved.

2 to 11 show a first embodiment of a method of manufacturing the semiconduit fiber bundle of the present invention shown in FIG. FIG. 2 is a diagram showing an optical fiber used in the present invention. A core glass 21 having a relatively high refractive index, and an acid resistant coated glass 22 having a relatively low refractive index and coated so as to surround the core glass 21. Further, the triple optical glass fiber 24 is composed of an acid-eluting glass 23 which is soluble in an acid and which is coated so as to surround the outer side thereof. Next, the triple optical glass fibers 24 are cut into a predetermined length, and inserted into the glass envelope tube 25 little by little from one end, and aligned so that hexagonal close packing is achieved. In this way, after a large number of triple optical glass fibers 24 are regularly arranged and filled in the outer tube 25,
One end 25A of the outer tube 25 is heated and completely sealed. (Figure 3)

Then, as shown in FIG. 4, the outer tube 25
A rubber tube 26 is connected to the open end portion 25B of the above and is connected to an appropriate vacuum exhaust device and an oxygen cylinder (not shown), and the outer tube 25 is installed in an electric furnace 27. After the outer tube 25 is vacuum-dried by preliminary evacuation, oxygen is supplied to the outer tube 25 from the outside and the outer tube 25 and the optical fiber 24 are heated to a temperature within a range where the outer tube 25 and the optical fiber 24 are not softened to burn out the outer tube 25 to remove foreign matters. The inside of the outer tube 25 is evacuated to a high vacuum of about 10 ⁻³ to 10 ⁻⁵ mmHg while baking and further heating. Then, the open end portion 25B of the outer tube 25 is heat-sealed and closed, and the closed portion is cut off to obtain a capsule-shaped closed tube 30 (see FIG. 5). This process is called a heat pack process.

Next, as shown in FIG. 5, after inserting the closed tube 30 into a metal closed container 31 having a diameter larger than that of the closed tube 30 and having one end closed, the container is closed. Three
The open end of 1 is sealed with a removable sealing lid 32. Thereby, the airtightness inside the container 31 is maintained. Then, the sealed container 31 in which the sealed tube 30 is sealed is inserted into the annular heating device 33. The inside of the container 31 is heated to the softening and fusion temperature of the optical fiber 24 by the heating device 33 in a high pressure state of nitrogen gas atmosphere, and kept in this state for several hours to eliminate the gap between the fibers. At this time, since the closed tube 30 is in a vacuum state, the pressurized gas in the closed container 31 uniformly presses the optical fibers 24 radially inward from the periphery of the closed tube 30, and thus the voids between the fibers are formed. All are closed to form an integrated and completely fused optical fiber bundle, which is subjected to high-pressure heat pack processing.

The optical fiber bundle 3 integrated in this way
After being gradually cooled, No. 4 is taken out of the container 31. (Refer to FIG. 6) This optical fiber bundle 34 has its outer periphery ground by a glass lathe to have a desired diameter, and both ends thereof are also cut at broken lines. Further, the outer circumference of the optical fiber bundle 34 is mirror-polished to remove fine scratches and is used as a parent conduit.

FIG. 7 is a diagram showing an apparatus for spinning a parent conduit. The parent conduit 35 is suspended at one end of the feeding device 36, and the parent conduit 35 is located in the spinning furnace 37. A main heater 38 and an auxiliary heater 39 are provided in the spinning furnace 37 to heat the parent conduit 35 to a desired temperature. A fiber outer diameter measuring device 40, a resin coating die 41, an ultraviolet irradiation curing device 42, a coating outer diameter measuring device 43, and a winding roller 44 are arranged below the spinning furnace 37.

When the parent conduit 35 is heated to a temperature at which it can be sufficiently stretched, it is wound up by inserting a fiber outer diameter measuring device 40, a resin-free die 41, a curing device 42, and a coating outer diameter measuring device 43. It is passed through the roller 44 and continuously pulled. When the fiber is passed through in this manner, the resin coating die 41 is filled with the ultraviolet curing type resin to be coated so that the outer periphery of the fiber can be coated with the resin. The resin-coated fiber is passed through an ultraviolet ray irradiation / curing device 43 to be cured by being irradiated with ultraviolet rays and is formed as a coating. Carbon is dispersed in the resin to block outside light. The resin to be coated may be a thermosetting resin. The wire diameter when pulled is measured by both measuring devices 40 and 43, and the feed rate of the take-up roller 44 is controlled by a control unit (not shown) to control the wire diameter to a desired value. . The pulled fiber having the desired wire diameter passes through the winding roller 44, is cut into a length suitable for the product, and is accommodated as a child conduit 45.

FIG. 8 is a view showing the accommodated child conduit 45. The child conduit 45 has a structure in which a resin coating 47 is applied to the outer circumference of an optical fiber bundle 46 in which a desired number of optical fibers are fused. , After the storage, the pixel part is inspected for defects,
It is sent to the next process. Both end surfaces 48 of the child conduit 45 are polished and finished, and then protective layers 49 for imparting weather resistance to the both end surfaces are formed by vapor deposition of vapor-deposited glass or the like. (See Figure 9)

Next, as shown in FIG. 9, a part of the covering layer 47 is peeled off, and as shown in FIG. 10, a part of the peeled side and the part of the covering layer 47 are covered with a heat shrinkable tube 50 to protect them. .
In this way, the child conduit whose necessary portion is protected is immersed in a glass dissolution tank (not shown) for eluting acid such as nitric acid for a certain period of time, the coating layer 47 is peeled off, and the acid of the uncovered portion 51 of the heat shrinkable tube 50 is removed. The eluted glass is eluted, and as shown in FIG. 11, the respective optical fibers of the portion 51 are separated into flexible portions 52 having flexibility, and the resin coating layer 47 is formed.
A long rigid portion 53 and a short rigid portion 54 having a groove are formed on both sides of the flexible portion 52. The boundary between the eluted and flexible portion and the uneluted portion is reinforced with an adhesive or the like.

As shown in FIG. 1, the eluting child conduit is fixed by covering the short side of the hard portion with the mouthpiece 16, and the flexible portion is covered with a protective tube 17 such as silicone. To be done. Nothing is coated on the remaining portion of the coating layer 47. It should be noted that the remaining portion of the coating layer may be covered with a base for fixing the position of the tip, and the flexible portion may not be covered with a protective tube.

According to the manufacturing method of the first embodiment as described above,
Since the hard part forms a resin coating thin film layer on the outer periphery during manufacturing, the outer diameter becomes smaller and it is possible to prevent scratches due to manual handling at the child conduit stage and to be attacked by moisture in the air, etc. Without, the resistance is improved.

FIGS. 12 to 14 show the second embodiment of the manufacturing method of the present invention.
An example is shown. FIG. 12 shows a spinning apparatus used in the second embodiment, which is different from the spinning apparatus of FIG. 7 only in that there is no resin coater or resin curing device. That is, the parent conduit 35 used in the second embodiment is manufactured by the same manufacturing method as that shown in the first embodiment, and the same feeding device 36 is used.
It is suspended at one end of the
Located within. The parent conduit 35 is heated to a predetermined temperature by a main heater 38 and an auxiliary heater 39, passed through a fiber outer diameter measuring device 40, and pulled downward by a winding roller 44. The pulled fiber is the take-up roller 4
After passing through 4, it is cut to a predetermined length and the child conduit 55
Will be housed as.

The sub-conduit 55 is arranged in a vapor deposition device (not shown), and vapor-deposited glass or the like is vapor-deposited over the entire circumference to form a protective coating layer 56, as shown in FIG. Next, the covering layer 56 of the portion to be made flexible is sandpaper 57.
Then, the undissolved portion is covered with a heat-shrinkable tube 50 for protection in the same manner as shown in FIG. 10, and immersed in an acid-eluting glass dissolving tank (not shown) for a certain period of time to peel off the coating layer 56 and heat. The acid-eluting glass in the uncovered portion of the shrinkable tube is eluted, and as shown in FIG. 11, each optical fiber in that portion becomes separated and becomes flexible.
The boundary between the eluted and flexible portion and the uneluted portion is reinforced with an adhesive or the like.

As in the case of FIG. 1, the eluting child conduit is fixed by covering the short side of the rigid portion with the mouthpiece 16, and the flexible portion is covered with the tube 17 of silicon or the like. . It should be noted that the remaining portion of the coating layer may be covered with a base for fixing the position of the tip, and the flexible portion may not be covered with a protective tube.

FIG. 15 shows a part of the third embodiment of the manufacturing method of the present invention. This third embodiment is the same as the second embodiment until the child conduit 55 is manufactured, and a description thereof will be omitted. In the third embodiment, a portion where the acid-eluting glass is eluted at the time of forming the protective coating layer is covered with a heat-resistant tape 58 such as an aluminum foil as shown in FIG. Remove the tape. After that, the flexible portion is formed by elution with acid in the same manner as in the second embodiment, and the base and the tube are fixed as shown in FIG.

[0023]

According to the present invention, the hard portion of the semi-conduit fiber bundle, of which only a part is flexible, is formed as the coating thin film layer. The outer diameter can be made small, and even if there is a bent portion on the hand operation part, it can be sufficiently coped with, and it is possible to cope with bending and twisting at the time of assembling, which facilitates the assembling. Also,
Since the hard part forms a thin coating layer on the outer circumference during manufacturing, the outer diameter becomes smaller, and it is possible to prevent scratches due to manual handling at the child conduit stage and to be attacked by moisture in the air. There is no increase in resistance.

[Brief description of drawings]

FIG. 1 shows a semi-conduit fiber bundle of the present invention.

FIG. 2 is a diagram showing optical glass fibers used in the semi-conduit fiber bundle of the present invention.

FIG. 3 is a diagram showing a step of filling an outer tube with optical glass fibers in the first embodiment of the production method of the present invention.

FIG. 4 is a diagram showing a heat pack step in the first embodiment of the manufacturing method of the present invention.

FIG. 5 is a diagram showing a high-pressure heat pack process in the first embodiment of the manufacturing method of the present invention.

FIG. 6 is a view showing an integrated optical fiber bundle manufactured by a high pressure heat pack process in the first embodiment of the manufacturing method of the present invention.

FIG. 7 is a diagram showing a step of spinning a parent conduit and coating a resin on the outer periphery in the first embodiment of the manufacturing method of the present invention.

FIG. 8 is a view showing a child conduit obtained by the first embodiment of the manufacturing method of the present invention.

FIG. 9 is a diagram showing a child conduit obtained by removing the resin of the flexible portion from the child conduit obtained by the first embodiment of the manufacturing method of the present invention.

FIG. 10 is a view showing a state in which a protective tube for acid elution is coated on the child conduit shown in FIG. 9 in the first embodiment of the production method of the present invention.

FIG. 11 is a diagram showing a state in which a flexible portion is formed by acid elution in the first embodiment of the manufacturing method of the present invention.

FIG. 12 is a diagram showing a step of spinning a parent conduit in the second embodiment of the production method of the present invention.

FIG. 13 is a diagram showing a state in which a coating thin film layer is formed on the outer periphery of a child conduit by vapor deposition in the second embodiment of the manufacturing method of the present invention.

FIG. 14 is a diagram showing a second embodiment of the manufacturing method of the present invention.
It is a figure which shows the process of removing the coating thin film layer of a flexible part from the child conduit of FIG.

FIG. 15 is a diagram showing a process of depositing a coating thin film layer in a third embodiment of the manufacturing method of the present invention.

FIG. 16 is a diagram showing a conventional rigid endoscope.

[Explanation of symbols]

 10 Semi-Conduit Fiber Bundle 11 Flexible Part 12 Hard Part 13 Hard Part 15 Coating Thin Film Layer 16 Base 17 Protective Tube 24 Triple Optical Glass Fiber Bundle 25 Outer Tube 35 Parent Conduit 37 Spinning Furnace 41 Resin Coat Die 42 UV Irradiation Curing Device 45 Subconduit 47 Resin coating 55 Subconduit 56 Covering layer 58 Heat resistant tape

Claims (17)

[Claims] 1. A plurality of optical fibers are aligned so as to correspond to each other at both ends, and a middle portion of the entire length is made into a flexible portion, and both ends of the flexible portion include both ends. In a semi-conduit fiber bundle having a hard portion, the length of one hard portion is made relatively longer than the length of the other hard portion, and a coating thin film layer is formed on the outer periphery of the one hard portion. A semi-conduit fiber bundle is characterized in that a mouthpiece is fixed to the other hard portion. 2. A plurality of optical fibers are aligned so as to correspond to each other at both ends thereof, and a flexible portion is provided at a middle portion of the entire length, and both ends of the flexible portion include both ends. In a semi-conduit fiber bundle having a hard portion, the length of one hard portion is made relatively longer than the length of the other hard portion, and a coating thin film layer is formed on the outer periphery of the one hard portion. A semi-conduit fiber bundle in which a base is fixed to the other hard portion and a flexible protective tube is coated on the flexible portion. 3. The semi-conduit fiber bundle according to claim 1 or 2, wherein the flexible portion has a length of 1
A semi-conduit fiber bundle characterized by being / 3 or less. 4. The semi-conduit fiber bundle according to claim 1 or 2, wherein the optical fiber of the hard part has a relatively high refractive index core glass, and a relatively low refractive index coated glass covering the core glass. And a semi-conduit fiber bundle, further comprising a triple fiber made of acid-eluting glass coated on the outside of the fiber and fused together. 5. The semi-conduit fiber bundle according to claim 1 or 2, wherein the coating thin film layer is an ultraviolet curable resin. 6. The semi-conduit fiber bundle according to claim 1 or 2, wherein the coating thin film layer is a thermosetting resin. 7. The semi-conduit fiber bundle according to claim 1 or 2, wherein the coating thin film layer is a vapor deposition material. 8. The semi-conduit fiber bundle according to any one of claims 1 to 7, wherein vapor-deposited glass is adhered to both end faces of the rigid portion, and a boundary between the flexible portion and the rigid portion is A semi-conduit that is reinforced by inserting resin. Fiber bundle. 9. A triple optical fiber comprising a core glass having a relatively high refractive index, a coated glass having a relatively low refractive index for coating the core glass, and an acid-eluting glass further coated on the outside thereof is convergently packed into an outer tube. To form a parent conduit, the parent conduit is hung in a spinning furnace, heated to a predetermined temperature and stretched to have a predetermined diameter, and the outer periphery thereof is coated with a resin and cured by a curing device to form a coating thin film layer. After the formation, a child conduit is formed by cutting it at a predetermined length, both end faces are polished, and then an end face protective layer is formed, a predetermined portion of the coating thin film layer is removed, and a portion of the portion where the coating thin film layer is removed is formed. A method for producing a semi-conduit fiber bundle, characterized in that a flexible portion is formed by eluting acid-eluting glass. 10. The method for manufacturing a semi-conduit fiber bundle according to claim 9, wherein the resin coat is applied through a pressure die. 11. A triple optical fiber comprising a core glass having a relatively high refractive index, a coated glass having a relatively low refractive index for coating the core glass, and an acid-eluting glass further coated on the outer side of the core glass is convergently packed in a jacket tube. As a parent conduit, the parent conduit is hung in a spinning furnace, heated to a predetermined temperature and stretched to a predetermined diameter while being stretched, and cut into a predetermined length to form a child conduit, and both end surfaces are polished. To form a coating thin film layer on the entire circumference with a vapor deposition device, remove the coating thin film layer in a predetermined part, and elute the acid-eluting glass in the part where the coating thin film layer is removed. A method for manufacturing a semi-conduit fiber bundle, comprising forming a flexible portion. 12. A triple optical fiber comprising a core glass having a relatively high refractive index, a coated glass having a relatively low refractive index for coating the core glass, and an acid-eluting glass further coated on the outer side of the core glass, is convergently packed into the outer tube. As a parent conduit, the parent conduit is hung in a spinning furnace, heated to a predetermined temperature and stretched to a predetermined diameter while being stretched, and cut into a predetermined length to form a child conduit, and both end surfaces are polished. From the above, a predetermined part of the outer peripheral surface is covered with a heat-resistant tape, a vapor deposition material is vapor-deposited to form a coating thin film layer, the heat-resistant tape is removed, and the acid-eluting glass of the uncoated portion of the coating thin film layer is removed. A method for manufacturing a semi-conduit fiber bundle, characterized in that a flexible part is formed by elution of the. 13. The method for manufacturing a semi-conduit fiber bundle according to claim 9, wherein the parent conduit is depressurized and sealed in the outer tube that converges and fills the optical fibers, and high temperature and high pressure are applied. A method for manufacturing a semi-conduit fiber bundle, which is characterized in that the respective fibers are fused together below. 14. The method of manufacturing a semi-conduit fiber bundle according to any one of claims 9 to 13, wherein the parent conduit has an outer periphery mirror-polished. Manufacturing method. 15. The method for manufacturing a semi-conduit fiber bundle according to claim 9, wherein the portion where the coating thin film layer is formed and the other end are protected by a heat-shrinkable tube. Then, the method for producing a semi-conduit fiber bundle is characterized in that acid is eluted in an acid elution tank. 16. The method of manufacturing a semi-conduit fiber bundle according to claim 9, wherein after forming the flexible portion, a resin is applied to a boundary between the flexible portion and the hard portion. A method for manufacturing a semi-conduit fiber bundle, which is reinforced by. 17. The semi-conduit according to claim 16.
A method for producing a semi-conduit fiber bundle, characterized in that the flexible portion is further covered with a flexible protective tube.