JPH01273007A - Method for coarsening optical fiber - Google Patents

Abstract

PURPOSE:To uniformly emit light by press-traveling an optical fiber thread or an optical fiber sheet-like material between a pair of a roller and a roller with fine projections on its surface. CONSTITUTION:The title method for coarsening optical fiber is to give fine projections to rollers 2 and 4, to pressurize and travel optical fiber between a pair of rollers 2 and 3 and a pair of rollers 4 and 5, thereby to give cracks and to leak light propagating in the optical fiber from the cracks. The number and size of cracks given to the optical fiber surface depend on the type of projections on the roller surface. If a sand paper no. 40, a coarse one, is used, the number of cracks on the surface is less and large cracks are given. Coarseness is compared in terms of light emitting brightness. If the roller with projections given by a sand paper no. 1000 coarsens optical fiber to form a light leaking part, longer material can emit light uniformly.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention effectively produces a roughened optical fiber useful for making optical fiber lighting tapes used for interior decoration, displays, and other lighting applications. It is about the method.

<Prior art> Conventional light leakage methods for plastic optical fibers include end face light leakage, in which light is emitted from the tip of the optical fiber, and side light leakage, in which light is emitted from the side surface of the optical fiber. Since it can cover a wide range of areas, it is increasingly being used as a lighting member.

As a means for side light leakage, a light leakage portion forming method is disclosed in JP-A-50-83044, in which the surface of the optical fiber is mechanically roughened by scraping the optical fiber with a sharp edge such as a knife. In addition, a so-called hot grate method is disclosed in JP-A-50-71966, in which a plastic optical fiber is pressed onto a heated rough plate to form the entire light leakage area. A method of forming a sharp light leaking portion is disclosed in Japanese Patent Application Laid-Open No. 170903/1983. Practically, hot stamping is often used because it is easy to process and it is easy to form light leaking parts.

<Problems to be solved by the invention> However, the currently used hot stamping method is capable of obtaining uniform light leakage when forming a light leakage portion on the optical fiber by roughening a small area of the optical fiber. When treating a large area of optical fiber for light leakage, or when roughening a long optical fiber to form a light leakage part, there is a method of roughening a predetermined length of optical fiber in several steps. In other words, the current situation is that we have no choice but to use a batch method.

However, this method has the problem that it is difficult to roughen the surface of a long optical fiber so that it can emit light uniformly, and brightness unevenness occurs regardless of the extent of the boundary between each bunch.

The entire purpose of the present invention is to provide a method for roughening optical fibers that solves all of these problems.

<Means for Solving the Problems> The present invention involves running an optical fiber thread or a sheet of optical fiber under pressure between at least a pair of rollers, one of which has fine protrusions on the surface; The gist thereof is a method for roughening the surface of an optical fiber yarn, which forms a light leakage part on the surface of an optical fiber yarn or an optical fiber sheet by running the optical fiber yarn under pressure through sandpaper between at least a pair of rollers. It is.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a side view showing an outline of the method for roughening an optical fiber according to the present invention, and FIG. 2 is a side view showing an outline of the method for roughening an optical fiber according to the present invention, which fully utilizes sandpaper as a roughening device. The side view of FIG. 3 is a graph showing the relationship between the length of the roughened surface and the brightness after the surface is roughened by the method shown in FIG.

The optical fibers used in the present invention may be either glass-based optical fibers or plastic-based optical fibers, but plastic-based optical fibers are preferred for ease of handling.

As shown in Fig. 1, the optical fiber yarn is formed by passing a sheet-like optical fiber (1) between one roller (2) and (3) with fine protrusions on the surface of one roller (2). A surface roughening method in which a light leakage portion is formed on the surface of an optical fiber yarn or optical fiber sheet (1) by running a pair of rollers (4) and (5) under open pressure. I can do it.

As shown in Susu 2, the optical fiber thread is formed between the optical fiber sheet (6) and the two pairs of rollers (8), (9), (10), and (11) with sandpaper (7) interposed between them. By running the fiber under pressure, a light leakage portion can be formed on the surface of the optical fiber yarn or optical fiber sheet (6).

As shown in FIG. 1, the method for roughening the surface of optical fibers of the present invention has fine protrusions on rollers (2) and (4), and between two pairs of rollers (2).
), (3), (4), and (5) are scratched by running the optical fiber under pressure, and the scratches are removed and the light propagating through the optical fiber leaks out. In order to emit light uniformly, it is determined by setting an appropriate combination of the running speed of the optical fiber, the nip pressure of rollers (2), (3), and rollers (4), (5), and the heating temperature of each roller. be done.

Also, the number and size of scratches created on the surface of the optical fiber depends on the nature of the protrusions on the roller surface, but if the surface of the roller is as rough as sandpaper 40@, the number of scratches will be small and large scratches will be created. be done. Also, on the contrary, sandpaper 15
If a roller with a fine surface such as No. 00 is used, many small scratches will be created.

Furthermore, as shown in FIG. 6, when comparing the luminance, even a long object can emit light evenly if the surface of the optical fiber is roughened using a roller with a protruding gold film of No. 1000 sandpaper to form a light leakage part.

Furthermore, even if the surface of the optical fiber is roughened using a roller provided with protrusions of approximately 320 grit sandpaper and a light leakage portion is formed, it is possible to emit light uniformly, and the absolute level of brightness is much higher than that of the former.

The fine protrusions may be formed by covering the entire roller with sandpaper of No. 40 to 1500, or by forming protrusions on the roller.

In the present invention, when the surface of the optical fiber is roughened to form all the light leakage parts, the key point is how to uniformly emit light from the long optical fiber, and as mentioned earlier, the running speed, roller nip pressure, and heating of each roller Temperature settings are important.

First, the roller nip pressure is basically 51rg/Cm.
It is possible to sufficiently roughen the surface of the optical fiber by setting the air control pressure within 2. The longer the optical fiber becomes, the more uniform the roughening process can be achieved by lowering the pressure, but at low brightness levels. becomes.

On the other hand, if high nip pressure is applied, the light will be severely attenuated, making it difficult to roughen the surface of a long optical fiber.

In addition, when the surface of a sheet of optical fiber is completely roughened to form a light leakage part, even with the same pressure setting, the wider the sheet width of the optical fiber, the more the pressure is dispersed, so the scratches caused by the roughening will be smaller and the brightness level will be lower. easy.

Furthermore, the surfaces of the pair of rollers may be either rubber, both metal, or a combination of rubber and metal, but it is preferable to use a combination of rubber and metal and coat the metal roller with sandpaper.

In the present invention, in order to efficiently roughen the optical fiber, a pair of rollers may be provided with a finely protruded roller, but it is preferable to use a finely protruded roller on each of the two pairs of rollers.

Next button Basically, each roller can be roughened without heating, and the four rollers are equipped with protrusions of about 40-inch size.
If the surface is roughened with a roller, it will not be affected much whether the roller is fully heated or not, but the finer the roller protrusions, the less likely it will be damaged by the pressure of the roller, so it is preferable to heat the roller. .

That is, by heating and pressurizing the optical fiber with a roller, the optical fiber is completely softened and its surface is roughened and easily scratched.

Also, since the softening state during the surface roughening treatment differs depending on the thickness of the optical fiber, it is best to set the temperature to suit the purpose of the roughening treatment.Generally speaking, the higher the heating temperature, the more likely it will be damaged. However, from the viewpoint of the heat resistance of optical fibers, the temperature is preferably 140C or less.

Furthermore, the running speed of the optical fiber has a smaller effect on the formation of scratches than the pressure of the roller and the heating temperature of the roller, but basically, the faster the running speed, the less likely it will be scratched.

The method of roughening the optical fiber shown in Figure 2 is carried out between two pairs of rollers (
8), (9), (10), and (11) are interposed with sandpaper (7) and run under pressure to scratch the optical fiber surface.The surface of each roller has protrusions. There is a great advantage that no rollers can be used at all.

Figure 1 shows the principle of surface roughening of optical fibers shown in Figure 2, and the luminescence status of optical fibers when conditions such as running speed, roller nip pressure, roller heating temperature, and sandpaper are changed.
Both methods have the same tendency as the surface roughening method, but by providing all appropriate conditions, it is easy to roughen the surface of a long optical fiber, form a light leakage part, and emit light uniformly.

Further, by driving the pair of rollers intermittently, a roughened portion and a non-roughened portion can be easily obtained.

Next, an actual case of the present invention will be shown.

Example 1 A woven tape was prepared in which optical fibers of 0.75i + diameter φ were arranged in a length of 10 lengths in warp yarns and normal yarns were used as weft yarns, and the surface was roughened by the method shown in FIG. 1 under the following conditions.

The fine protrusion rollers were coated with No. 320 sandpaper, and each roller (4 rollers) was made entirely of hard rubber.

Assemble the roughened optical fiber sheet 13 as shown in Figure 4.
Connected to a V-5W light source, 11000i between a and d in the same figure.
, where a is the left end, b = position 360 degrees from point a, C: position 660 balls from a, d: 1oo from a.
As shown in Table 1, the results of all the brightness measurements at the positions in the order of o were obtained, as compared to the hot stamping method, an optical fiber sheet was obtained that emitted light more uniformly.

Example 2 A woven tape was prepared in which optical fibers of 0.75111+11φ were arranged in a width of 10 in the warp, and the surface was roughened by the method shown in FIG. 2 under the following conditions.

Incidentally, sandpaper No. 320 and each roller (four) were made of hard rubber.

When a light source was incident on the roughened optical fiber sheet from the convergent end and the brightness was measured, an optical fiber sheet was obtained that emitted light uniformly without unevenness in the width direction compared to the Honstamp method. The obtained optical fiber with a roughened surface length of 600 mm was connected to a light source as shown in FIG.
Table 2 shows the results of measuring the brightness at a position 400 meters away from point a and at a position 600 meters away from point d.

<Effects of the Invention> As shown in FIGS. 1 and 2, the present invention runs under pressure between at least a pair of rollers to roughen the surface and form a light leakage portion, so that a long optical fiber can uniformly emit light. In addition, roughening can be easily achieved using a wide sheet.

Furthermore, compared to the conventional batch-type hot stamping method, productivity is higher due to continuous surface roughening, and the effects of the present invention are extremely significant in industrial terms.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the method of the present invention in which rollers having fine protrusions on their surfaces are run under pressure, and FIG. 2 is a schematic diagram of the method of the present invention in which sandpaper is interposed between the rollers and the rollers are run under pressure. FIG. 6 is a graph showing the relationship between the length of surface roughening and brightness, and FIG. 4 is a diagram showing the state of brightness measurement of the obtained roughened optical fiber tape. Patent applicant Mitsubishi Rayon Co., Ltd. Agent Patent attorney 1) Toshizu Muratake 4 CM

Claims (1)

[Claims] 1) Light leakage portions are formed on the surface of the optical fiber yarn or sheet by running the optical fiber yarn or sheet-like object under pressure between at least a pair of rollers, one of which has fine protrusions on the surface. A method for roughening an optical fiber, the method comprising: forming a surface roughening method for an optical fiber.