JPH06174949A - Plastic fiber optic plate - Google Patents

Abstract

PURPOSE:To provide the high resolution plastic fiber optic plate formed of a multifiber without using an adhesive. CONSTITUTION:This plastic fiber optic plate is composed of the clad consisting of the polymer having low refractive index which is obtained by heating and melting the multifiber without using the adhesive to weld and integrate each of clad polymers, and the core consisting of the polymer having high refractive index and <=50mum diameter. Therefore, the structural body which has no clearance due to the adhesive, and is high in resolution, large in the ratio of total occupancy area, bright, further, connected continuously and uniformly is obtained, therefore, resolution is constant at every parts.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to plastic fiber optic plates. Specifically, it relates to a plastic optical fiber array. The fiber optic plate is widely used as an image transmission part in office automation equipment, measurement, transmission parts, semiconductor related fields, etc. for image transmission in reading and writing of fax machines, copiers, printing machines, etc. Applications are expanding.

[0002]

2. Description of the Related Art A fiber optic plate currently used for reading and writing an image sensor has conventionally used a silica optical fiber having a small diameter due to the problem of pixel fineness. Using a thin optical fiber, form a light blocking layer around it, fuse these,
Cut to an appropriate length and polish the end faces to make a fiber optic plate. Here, the core is a name used to represent a fiber structure, and the pixel is a name used to represent one component of an image.

The silica-based fiber optic plate produced in this manner has a high fiber itself, but has a drawback that the subsequent processing such as end face polishing takes a lot of work and the cost becomes high. On the other hand, the method of making a plastics-based high-resolution fiber optic plate has been studied, though a manufacturing method using optical lithography has been examined, but it has not been established yet.

[0004] The manufacturing method that is generally used at present is to arrange several hundred plastic multi-fibers according to the application,
There is a method of solidifying the gap with an adhesive to make a fiber optic plate, but this method creates a gap between multifibers, and this gap part not only becomes a loss part of light transmission but also does not transmit light Therefore, the resolution was also poor.

Therefore, in order to make a fiber optic plate having a higher resolution, it is necessary to further reduce the diameter of the optical fiber to be used and arrange them in a neat manner. There is a possibility that the fiber diameter up to about 100 φμm can be produced by this method, but it is practically impossible to produce it with a thinner fiber due to problems of workability and cost. Such a plastic-based high-resolution fiber optic plate is not currently manufactured.

[0006]

The object of the present invention is to solve the problems in the conventional manufacturing method as described above, and to have a high resolution as high as that of a quartz system by the new method, which can be used as an image transmission component. The purpose is to easily provide an inexpensive plastic fiber optic plate.

[0007]

The present inventor has found that
The present invention has been found out by conducting intensive research in order to develop a high-resolution plastics fiber optic plate composed of the following core assembly. That is, the present invention is as follows. 1. A plastic fiber optic plate composed of a clad made of a polymer having a low refractive index and a core made of a polymer having a high refractive index, wherein the maximum diameter of the core is 50 μm or less, and the cross section of the plastic fiber optic plate. A plastic fiber optic plate characterized in that the structure is a sea-island structure composed of island-forming cores and sea-forming cladds. 2. The plastic fiber optic plate according to claim 1, wherein the low refractive index polymer constituting the clad is colored. 3. In a plastic fiber optic plate composed of plastic multi-fibers, the plastic multi-fibers are composed of a clad composed of a polymer having a low refractive index and a core composed of a polymer having a high refractive index and having a maximum diameter of 50 μm or less, and The cross-sectional structure of the multi-fiber has a sea-island structure composed of a core forming an island and a cllad forming an ocean, and further, a metal vapor deposition layer is arranged on the outer periphery of the plastic multi-fiber. Plastic fiber optic plate. 4. It is composed of a clad made of a polymer having a low refractive index and a core made of a polymer having a high refractive index, and the core has a maximum diameter of 50 μm or less, and has a cross-sectional structure of a core forming an island and a cladado forming a sea. A method for producing a plastic fiber optec plate, which comprises arranging plastic multi-fibers having a sea-island structure in close contact with each other in a mold and performing heat fusion bonding.

The present invention thermoforms a plastic multi-fiber assembly in which a predetermined number of core polymers of 50 .mu.m or less made of a high refractive index polymer are arranged in a matrix which is a clad polymer made of a low refractive index polymer. It is a plastic fiber optic plate obtained by the above, and has a high resolution that has never been seen before.

That is, according to the present invention, since an aggregate composed of plastic multi-fibers is heated and re-melted and deformed, and clad polymers are melt-bonded to each other, there is no gap due to the adhesive, the resolution is high, and the total occupied area of the core is high. It has the advantage that the resolution is constant in every part because it is a bright structure due to a large proportion and is a continuous and uniformly connected structure.

The feature of the method for producing a plastic fiber optic plate of the present invention is that the largest feature of the present invention is to produce a large size of plastic fiber plates that are continuously connected by using plastic multi-fibers. . In the present invention, the fiber optic plate is a plate in which multi-fibers having a diameter of 0.5 to 10 mm are arrayed and melt-bonded to each other to form a plate, and both surfaces are polished, and a thickness of 0.
A plate-shaped product having a size of 4 mm or more and a width of 10 mm or more. Multi-fiber has a diameter of 0.5-
Up to 10 mm.

The multifiber used in the present invention comprises a clad made of a polymer having a low refractive index and a core made of a polymer having a high refractive index and having a maximum diameter of 50 μm or less, and the cross-sectional structure of the multifiber has a sea-island structure. Anything that can be taken is used. As an example, by combining melt spinning and precision shaping technology, the size of the part corresponding to the core polymer of the island part made of the polymer of high refractive index, in the part corresponding to the clad polymer of the sea part made of the polymer of low refractive index, It is a multi-fiber having 3500 cores, for example, which can be manufactured by simultaneous extrusion using a multi-fiber die designed to have a diameter of 1 to 50 μm or less.

The outer shape of the multifiber becomes a circle by extrusion drawing, and the outer diameter of the multifiber and the core diameter of each of the multifibers can be made thin by changing the draw ratio. This multi-fiber,
Depending on the application, hundreds of them are lined up and heat-melt bonded to form a plate, which makes it possible to easily make a high-resolution plastic fiber optic plate with a core diameter of 50φμm or less, which was impossible with the conventional method. Became.

Regarding the relationship between the refractive index of the core and the cladding in the present invention, it is sufficient that the refractive index of the core is slightly larger than the refractive index of the cladding. The larger the difference in refractive index, the larger the numerical aperture (NA), and the larger the light-receiving angle, the larger the amount of light that is transmitted and the brighter it becomes. If parallel light is required, N. A. Can be small, and if a wide viewing angle is required, N. A. Needs to be increased. That is, the refractive index of the core and the clad may be determined according to the application. Polystyrene, polymethylmethacrylate, polycarbonate, and copolymers containing these as the main components are used as the high refractive index polymer used for the core, and the low refractive index polymer used for the clad is a fluorine-based polymer or , Polymethylmethacrylate, or copolymers containing these as the main components are used.

Multifibers made of such materials are cut into a predetermined length and arranged in parallel in a mold, and the mold is heated by a hot press to apply a slight pressure, or By utilizing the heat shrinkage force of the fiber, the polymer of each clad part of the multi-fiber is heat-melted and adhered to each other, and then the mold is cooled and taken out from the mold, thereby integrating without the adhesive layer. The high-resolution plastic fiber optic plate of the present invention can be easily obtained. The heating conditions are 120 to 150 ° C and 5-1.
5 minutes heating time is good. If the temperature is lower than 120 ° C., melt adhesion does not occur, and if the temperature is higher than 150 ° C., the flow of the polymer is improved and the structure of the multifiber may be broken, which is not preferable. 1Kg / cm ² when pressurizing
Moderate pressure is sufficient. Furthermore, if necessary, the fiber optic plate having a shape suitable for various uses can be obtained by cutting or polishing the end faces.

Depending on the application, it is necessary to provide a light absorber layer in order to prevent stray light. For this, a method of adding a small amount of dye to a clad polymer having a low refractive index to prevent light transmission. Alternatively, there is a method of coating the light absorber layer on the outer side of the extruded multifiber, a method of vapor-depositing a metal such as Al very thinly, or the like. A
The vapor deposition thickness of 1 is preferably about 0.1 to 50 μm.
When the thickness is less than 0.1 μm, the effect of preventing stray light of light is not so great, and when the thickness is more than 50 μm, it is effective in preventing stray light of light, but the heat fusion bonding which is a feature of the present invention can be performed. Disappear. If the Al layer is a thin layer of about 0.1 to 50 μm, the multifiber is deformed by thermoforming, the Al layer is broken in places, and the clad polymer appears on the surface, so that melt adhesion becomes possible.

By using these methods properly according to the application, it is possible to satisfy the required performance of high resolution as an image transmission component, and by the novel manufacturing technique of the present invention, a considerably large size fiber optic plate can be obtained. It can be obtained easily and inexpensively, and will be widely used in many fields as an image transmission device which is required to have higher resolution and larger size in the future. In particular, since the fiber optic plate of the present invention is made of plastic, it is less likely to break than conventional glass and is more resistant to shock and vibration, so it will be widely used in the future as a mobile device component such as a fax for automobile loading. used.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

[0018]

Example 1 A plastic multis fiber having an outer diameter of 1.0φ mm and consisting of 3500 cores was cut into a length of 50 mm, 50 pieces were arranged in the lower mold 2 in FIG. 1, and 1 upper mold was set and pressed. Molded. The conditions were heating at 140 ° C. for 5 minutes, applying a slight pressure as shown in FIG. 2, then cooling the whole as it was, and taking out from the mold to prepare a plastic fiber optic plate. The shape of the plastic multi-fiber at this time had a rectangular cross section. The size of the resulting plastic fiber optic plate is 0.7 mm in thickness, 50 mm in length, and 50 in width.
Although it was mm, it was divided and cut into the required length (3 mm), and the cut end surface was polished and finished.
A plastic fiber optic plate was obtained.

[0019]

[Example 2] A plastic multis fiber having an outer diameter of 2.0 mm and consisting of 3500 cores was cut into a length of 50 mm, and in the lower mold of FIG. Was set and allowed to stand in a hot air oven, and the fibers were contracted, melt-bonded, and integrated. The conditions of the hot air oven were heating at 100 ° C. for 30 minutes, further heating at 120 ° C. for 20 minutes, and then taking out from the oven and cooling the whole as it was, taken out from the mold to prepare a fiber optic plate. The shape of the multifiber at this time was a pentagon. This was divided into required lengths (5 mm) and cut, and the cut end faces were polished to give a fiber optic plate.

[0020]

Example 3 To prevent stray light, aluminum was vapor-deposited to a thickness of 0.1 μm on the outside of a plastic multisheath having an outer diameter of 2.0φ mm consisting of 3500 cores, which was developed by the present inventor. It was cut into a length of 50 mm, 25 pieces were arranged in the same manner as in FIG. 1, and press-molded. The conditions were heating at 140 ° C. for 5 minutes, applying a slight pressure, cooling the whole as it was, and taking it out from the mold to prepare a fiber optic plate. The fiber optic plate size is 1.6 mm thick,
The length was 50 mm and the width was 50 mm, but this was divided and cut into a required length of 3 mm, and the cut end face was polished to obtain a fiber optic plate having an absorber layer. FIG. 6 is a schematic cross-sectional view of an optec plate having the resulting absorber layer.

A straight line having a width of 0.2 mm was observed using the fiber optic plate prepared in Examples 1 to 3 and the one prepared by the conventional method. The conventional method differs depending on the place and appears as a dotted line. On the other hand, the products prepared in Examples 1 to 3 appeared to be a clean straight line in every part.

[0022]

The resolution is high because there is no gap due to the adhesive, and it is bright because the ratio of the total occupied area of the core is large.
Also, in order to form a continuous and evenly connected structure,
The resolution is constant in every part.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of multi-fiber alignment before heating and melting in Example 1.

FIG. 2 is an explanatory diagram showing a state of multifiber after pressure melting and adhesion.

FIG. 3 is an explanatory diagram of alignment of multifibers before contraction in Example 2.

FIG. 4 is an explanatory view showing a melt-bonded state in which the multifiber is shrunk by heating.

FIG. 5 is a schematic cross-sectional view of a multifiber having a light absorber layer made in Example 3.

FIG. 6 is a schematic view showing a part of a cross section of the fiber optic plate obtained in Example 3.

[Explanation of symbols]

 1 Upper mold 2 Lower mold 3 Multifiber 4 Clad polymer with low refractive index 5 Core polymer with high refractive index 6 Al layer deposited on the outside of multifiber

Claims (4)

[Claims] 1. A plastic fiber optic plate comprising a clad made of a polymer having a low refractive index and a core made of a polymer having a high refractive index,
The plastic fiber optic plate, wherein the maximum diameter of the core is 50 μm or less, and the cross-sectional structure of the plastic fiber optic plate is a sea-island structure composed of a core forming an island and a clad forming a sea. . 2. The plastic fiber optic plate according to claim 1, wherein the low refractive index polymer constituting the clad is colored. 3. A plastic fiber optic plate composed of plastic multi-fibers, wherein the plastic multi-fibers comprise a clad composed of a polymer having a low refractive index and a core composed of a polymer having a high refractive index and having a maximum diameter of 50 μm or less. And a cross-sectional structure of the plastic multi-fiber has a sea-island structure consisting of a core forming an island and a cllad forming a sea, and a metal vapor deposition layer is provided around the outer periphery of the plastic multi-fiber. A plastic fiber optic plate characterized by having 4. A clad made of a low refractive index polymer and a core made of a high refractive index polymer,
The maximum diameter of the core is 50 μm or less, and the cross-sectional structure is a plastic multifiber having a sea-island structure composed of an island-forming core and a sea-forming clad, which are closely arranged in a mold and heat-melted. A method of manufacturing a plastic fiber optic plate characterized by bonding.