JPS63237003A - Optical fiber sheet - Google Patents

Abstract

PURPOSE:To receive a distinct image causing no disturbance in a transmitted image in optical communication by forming a sheet of optical fiber having a sea-island structure forming a core of the optical fiber of plural island components by fuse-welding the sea component between plural number of the optical fiber to an adjacent sea component to each other, thereby fixing the relative position of the island component invariably independently of the direction of the axis of a cable. CONSTITUTION:A sheet of optical fiber is formed in optical fiber 1a, 1b, 1c... having a sea- island structure wherein the core of the optical fiber is constituted of plural island components, by fuse-welding adjacent sea components to each other between the optical fiber, and the relative position of the island components is fixed independently of the direction of the axis of a cable. Plural island parts 2a, 2b, 2c... in the sea-island structure of each optical fibers 1a, 1b, 1c... are constituted of a polymer having higher refractive index than the material for the sea part 3, so light is transmitted through the island parts 2a, 2b, 2c.... The polymer constituting the island parts 2a, 2b, 2c... may be a transparent polymer having higher refractive index than the polymer for the sea part 3. Polymethyl methacrylate, copolymers consisting primarily of polymethyl methacrylate, polystyrene, and copolymers of styrene, polycarbonate, etc. are preferred. By this constitution, a distinct image is obtd. without causing disturbance in the image, and an optical fiber sheet suitable for light transmission is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an optical fiber sheet used for a high-performance image guide having an extremely large number of pixels.

[Prior Art] Conventionally, optical fiber sheets have been used as elements for various image guides and sensor heads, or for displays, and the range of applications is increasingly expanding.

Various manufacturing methods have been proposed for optical fiber sheets. As one such method, Japanese Patent Laid-Open No. 49-8452 and No. 49-90151 describe a method of winding and fixing optical fibers in a single row on a drum.

However, although the width of the optical fiber sheet obtained by this method is variable, the sheet length is limited. Moreover, the manufacturing method had poor productivity and was inefficient.

As a continuously manufactured optical fiber sheet, a large number of optical fibers are moved from a yarn feeding creel using a number of guides such as reeds, as proposed in JP-A-50-46340 or JP-A-58-68006. There are some that are made into sheets by warping and gluing them.

The optical fiber sheet obtained by this method uses a large number of guides and the like during its manufacture, which prevents scratches on the surface of the optical fibers and makes it extremely difficult to maintain constant tension between each optical fiber. There was a problem that unevenness occurred on the sheet. Furthermore, the optical fiber sheet obtained by this method requires the use of adhesive, and when laminated to create an image guide, uneven thickness and width occur due to uneven adhesive, resulting in a problem of lack of uniformity. was there.

On the other hand, as an efficient method to continuously form sheets,
9-29646, Japanese Patent Publication No. 42-27585, and Japanese Patent Application Laid-Open No. 50-8540, methods of fusion bonding during the spinning process of fibers or optical fibers have been proposed. The optical fiber sheet obtained by this method is a continuous optical fiber sheet that does not use adhesive, and is a good sheet.

However, when it comes to optical fiber sheets with a diameter of 50μ or less, the fibers themselves are extremely thin, so the sheets are too flexible, and it is difficult to determine the relative positions of the sheets when stacking them.
There was a problem that lamination was difficult.

On the other hand, Japanese Patent Laid-Open No. 56-39505 proposes a sea-island type optical fiber, and proposes a high-performance optical fiber for optical fiber image guide.

However, when assembling this fiber, it is extremely difficult to position the fiber due to twisting of the fiber, and it is rarely possible to match the optical positions of one end face and the other end face one-to-one.

[Problems to be Solved by the Invention] The present invention was obtained as a result of intensive investigation to improve the above-mentioned drawbacks of the prior art. The purpose is to provide an extremely high-performance optical fiber cable whose positional relationship remains unchanged.

[Means for Solving the Problems] In order to achieve the above object, the present invention has the following configuration.

That is, an optical fiber having a sea-island structure in which a plurality of island components form a core part is formed into a sheet by fusion of adjacent sea components between the optical fibers, and the relative positional relationship of the island components is determined according to the cable. An optical fiber sheet characterized by being unchanged in the 411 direction.

The present invention will be explained in more detail below.

FIG. 1 is a perspective view showing one embodiment of the optical fiber sheet of the present invention. In Figure 1, 1a, '+b, '+c
... must be one optical fiber each, 2a, 2b
, 2C... are a plurality of sea areas with a sea-island structure. The sea portions are made of a polymer having a higher refractive index than the sea portions 3, and light is transmitted through the sea portions 2a, 2b, 2C, . . . .

The polymer forming the sea area only needs to be a highly transparent polymer with a refractive index higher than that of the sea area, and suitable examples include polymethyl methacrylate, copolymers containing it as a main component, polystyrene and copolymers, polycarbonate, etc. used for.

The polymer constituting the 7Itj portion 3 only needs to be a polymer with a refractive index lower than that of the island component, and for example, fluorine-containing methacrylate polymers, vinylidene fluoride and its copolymers, polymethyl methacrylate polymers, etc. are preferably used. be done.

The number of Kai parts is not limited, but is used in a range of 2 or more to several hundred pieces. , one sea area is one pixel unit, so it is preferable to have as many as possible.

The cross-sectional shape of the sea area may be circular, non-circular, such as a close-packed hexagon, triangular, elliptical, or irregular, and there is no problem in transmitting light within a range of 2 to 5 meters, which is the range used for image guides. . Although there is no limit to the diameter of each fiber, it is preferably about 100 μm or more and about 1000 μm from the viewpoint of ease of handling and stacking.

The optical fiber sheet of the present invention consists of these individual optical fibers 1
a, 1b, 1c, . . . are formed by fusion bonding at adjacent portions of each sea portion 3.

Next, one example of the method for manufacturing an optical fiber sheet of the present invention will be described.

FIG. 2 is a model diagram of a die for manufacturing the optical fiber sheet of the present invention, showing a part of the die. 4 is the base. 5 is an island component inflow part, and 6 is a sea component inflow part. Reference numeral 7 denotes a dividing portion of the island component, where a plurality of island components corresponding to the holes are formed. 8 is a composite part of sea-island components. Reference numeral 9 denotes a discharge hole through which the composite polymer 8 is discharged to form a fiber. Figure 3 shows the spinning section under the nozzle 4.
is a collective guide. The fibers discharged from the discharge hole 9 are collected by the collection guide 10 before being cooled, and the sea component is fused and bonded to form a sheet, thereby obtaining the optical fiber sheet 11 shown in FIG. .

FIG. 4 is a schematic diagram illustrating the relative positional relationship of island components, which is the most significant feature of the present invention. X is the light incident end face, Y
is a virtual cut end surface, and Z is a light exit end surface. In the island components of each independent optical fiber 1a, 1b, 1C1, 1a, A, B, C, 'lb, aSb, c, 1c,
They are labeled as A, 口, and Ha.

The fiber sheet of the present invention can be used at any position in the axial direction of the cable, that is, the light input end face X, the virtual cutting end face Y, and the light output end face Z.
, bSc and the relative positions of A, 口, and C remain unchanged. However, since the optical fiber sheet of the present invention is flexible and easily bent, the relative positional relationship remains unchanged only when the sheet is placed flat as shown in the figure. Although the relative position changes when it is curved or bent, this is just one example of the usage of the present invention and is included in the present invention.

This is because if the form of the present invention is maintained in a flat state, disturbance of the transmitted image will not occur in principle, and the purpose of the present invention is to prevent image disturbance. be.

The present invention will be explained in more detail below with reference to Examples.

[Example] Example 1 Polymethyl methacrylate was used as the island component, vinylidene fluoride and tetraflu A copolymer were used as the sea component, and the second
With the die of the type shown in the figure, the number of island components is 24, the number of discharge holes is 40, and the discharge of polymethyl methacrylate is 8. It was set to On/min. Also, the sea component is 9.03g
The discharge amount is /min, and the spinning speed is 1 om,,'m.
The optical fiber sheets were collected as in, collected using a collection guide, and fused to form an optical fiber sheet.

The obtained optical fiber sheet has an average diameter of island components of 30 μm.
1. The width was approximately 1 Qmm. In addition, in the optical fiber sheet, the relative positions of the island components are the incident end surface X, the virtual cut end surface Y,
All exit edges Z had the same structure. When this optical fiber sheet was tested for light transmission, the image was clear and undisturbed.

[Effects of the Invention] In the present invention, even if the number of pixels is large, the local relative positional relationship remains unchanged in the axial direction of the cable, so the transmitted image is not disturbed. Therefore, it is possible to provide an excellent high-performance image guide that can clearly receive images.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing one embodiment of the optical fiber sheet of the present invention. FIG. 2 is a schematic cross-sectional view of a model of a die for manufacturing the optical fiber sheet of the present invention. FIG. 3 shows an example of a spinning and assembly method for producing the optical fiber sheet of the present invention. FIG. 4 is a schematic diagram illustrating the relative positional relationship of island components. 1a11b11C... Age: Optical fibers 2a, 2b, 2C---: Local part 3: Sea part 4: Base 5: Island component inflow part 6: Sea component inflow part 7: Island component division part 8: Composite part 9: Discharge hole 10 : Collection guide 11: Optical fiber sheet

Claims (1)

[Claims] (1) An optical fiber with a sea-island structure in which a core portion is formed by a plurality of island components is formed into a sheet by fusion of adjacent sea components between the optical fibers, and the relative positional relationship of the island components is An optical fiber sheet characterized by being unchanged in the axial direction.