JPS6398606A - Optical fiber line light - Google Patents

Abstract

PURPOSE:To reduce spots formed in a projection angle light quantity distribution without being affected by curving by carrying out a scattering treatment on optical fiber end surfaces which constitute a line light. CONSTITUTION:Many optical fibers 3 are arrayed, their one-terminal sides 1 are fixed in a line as a light incidence or projection terminal, and the other- terminal sides are arrayed in a line or bundled as a light projection or incidence terminal to constitute the line light, and at least the end surfaces 1 or 6 of the optical fibers as the light incidence/projection end surfaces are treated for scattering. Namely, the scatter treating method of the optical fiber end surfaces is, for example, a coating method, a blast method, a roughening method by rough polishing, etc. Then when the fiber end surfaces 1 or 5 are treated for scattering as the incidence end surface, the localization of the angle light quantity due to bending in high-degree mode is reduced. When the end surfaces are treated for scattering as the projection end surface, on the other hand, the localized angle light quantity is decentralized.

Description

[Detailed Description of the Invention] [Field of Industrial Use] The present invention relates to a line light optical system that can be effectively used as a line light source for optical office equipment, particularly copying machines, etc. Regarding the next fiber optic line light.

[Conventional technology]

Fluorescent lamps and linear halogen lamps are generally used to obtain linear light sources, but due to their structure, it is difficult to make them long while maintaining the uniformity of the light amount in the longitudinal direction. A friend who naturally has a limit. However, with the rapid commercialization of optical fibers in recent years, one end of the optical fibers has been bundled into a cylindrical shape.
A line light is made that obtains a line-shaped light source by inputting light from the end of a cylinder, aligning the other ends one by one in a line, and emitting light from the line-shaped end.
By increasing the number of 7-eye bars, it became possible to easily obtain long ones.

[Problem to be solved by the invention] When this line light using optical fibers is used for general lighting, unevenness in the amount of light in the line direction does not pose a particular problem, but optical office work has developed rapidly in recent years. In the field of advanced optics such as equipment, such unevenness in the amount of light in a linear direction has become a serious problem.

There are various causes of this light intensity unevenness, but as a result of our investigation, we found that in addition to the light source unevenness caused by lamps, etc. It turned out that unevenness in the output angle light intensity distribution due to differences in bending was also a major factor.

That is, the problem to be solved by the present invention is the unevenness that occurs in the light output angle distribution due to the difference in the bending of each optical fiber of the line light optical system.

[Problem t-Means for solving]

As a solution, it is extremely difficult to make the bending of the optical fiber uniform, and eliminating the bending entirely would mean not being able to utilize the greatest feature of the optical fiber.
It's not realistic.

Therefore, we have been conducting extensive research to find a way to prevent unevenness in the output angle and light intensity distribution even if there are differences in the bending of each optical fiber.As a result, we have developed a method to prevent the bending from occurring by applying scattering treatment to the end face of the optical fibers that make up the line light. A friend who found that it lowers plaque without being affected.

That is, the present invention arranges a large number of optical fibers and arranges and fixes them in a line on one end to serve as the light input or output end, and the other end is arranged in a line or in a bundle to serve as the light output or input end. In the line light that is intercepted, the line light is a slightly uneven line light characterized in that at least -7 of the end face of the optical fiber, which is the light input/output end face, is subjected to scattering treatment.

The scattering treatment method for the optical fiber end face is a method of dispersing light, and t'L is generally not limited, but includes, for example, coating with a light scattering substance, a plasting method, and a surface roughening method by rough polishing. Although scattering treatment for one end face of the original fiber is effective when both end faces are performed, the effect is produced even if only -7 is performed.

[Action and effect]

The effect of applying scattering treatment to one end face of the fiber is to convert the incident light into a higher-order mode at the input end face, resulting in uneven distribution of the angular light amount due to bending, and at the output end face, to This is to disperse the unevenly distributed angular light amount. Since one end face of the crossed fibers can be treated with sandpaper or the like without expensive or sophisticated optical polishing, there is a great effect in terms of reducing processing costs.

〔Example〕

Example 1 A bending jig (with a radius of curvature of 15 wa
, ) Attach f and insert the fiber 9 along the bend.
It was bent at an angle of 0° and made into a full straight line 15 degrees from the point where the song 9 ended, and the output angle light amount distribution was measured at the end face.

Both end faces of the optical fiber were roughly polished with sandpaper ÷ 400, and the distribution of the output light amount near the fiber angle of 0° at that time is shown in Figure 19.

On the other hand, FIG. 2 shows a similar output light amount distribution of a line light having an end portion only subjected to optical polishing. Comparing the two figures, it is clear that the line light with roughened end faces has a greatly improved output photoelectric distribution.

Example 2 Line shape with a length of about 220 m and a diameter [L75 am (core diameter E
In a line light with the shape shown in Figure 5, in which 300 optical fibers with a core-sheath structure of 73 m) are lined up and the other end is bundled to form a bundle part with a diameter of 15.6 m, sandpaper is placed at the input and output ends of the optical fibers. A rough polishing process was performed at +400, and light was incident on the bundle portion, and the distribution of the amount of light emitted from the linear portion was measured. The entire result is shown in Figure 4.

From this result, it can be seen that the light intensity unevenness is greatly reduced after the edge roughening treatment compared to the light intensity uneven distribution with the edge portion only subjected to optical polishing as shown in FIG.

[Brief explanation of the drawing]

FIG. 1 shows the light intensity distribution of the light output angle when the input and output end faces of one fiber shown in Example 1 were subjected to rough polishing. FIG. 2 shows the light intensity distribution at the output angle when the input and output end faces of one fiber shown in Example 1 were subjected to conventional optical polishing. 3 and 4 show uneven distributions of light intensity emitted from the line portion of the next line light optical system shown in Example 2. FIG. 5 is an example showing the entire line light. 1 Two-line part fiber one end face Two-line part cap 6: Original fiber 4: Bundle part cap 5: Bundle part completed 1 bar One end surface Light amount Light amount Unprocessed line Light lay>Jt (mrn) Line light line length voice m) ;1i=4 Figure 5 Figure

Claims (2)

[Claims] (1) A large number of optical fibers are aligned, one end of which is arranged in a line and fixed as a light input or output end, and the other end is arranged in a line or bundled and configured as a light output or input end. 1. An optical fiber line light characterized in that a scattering treatment is applied to at least one end face of an optical fiber, which is a light input/output end face. (2) Claim 1, characterized in that the scattering treatment on the end face of the optical fiber is performed by rough polishing.
Line light as described in section.