JPS61113012A - Lighting optical device for optical fiber - Google Patents

Abstract

PURPOSE:To obtain a lighting optical device for an optical fiber which has high light convergence efficiency and compact constitution by providing an elliptic mirror which has a circular hole and a deep depression, a lamp inserted into the circular hole, and a condenser lens in front of the lamp. CONSTITUTION:The elliptic mirror 1 is in a deep-depression bowl shape and is provided with the circular hole 6 in its center. The lamp 2 is inserted into a socket 8 fixed to a housing 7, but the lamp 2 is installed penetrating the circular hole 6 from behind the elliptic mirror 1 so that its light emission part 3 is positioned at the focal point F1 of the elliptic mirror 1. On the other hand, the optical fiber 3 is fitted to the fixed holder 9 of the housing 7 and its incidence end surface is positioned at the other focus F2. A lens frame 11 and the condenser lens 12 are provided fixedly on the optical axis of the optical path between the lamp 2 and fiber 4, and luminous flux from the light emission part 3 is converged on the optical fiber 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical fiber illumination device.

] ■L Prefecture In such illumination optics, an elliptical mirror is used, and the light emitting part of the light source lamp is placed at one focus of the mirror, and the end face of the optical fiber is placed at the other focus. The method is conventionally known. In this type of illumination system configuration, the lamp is located between the elliptical mirror and the optical fiber, so both the light flux from the light source that enters the elliptical mirror, and the light flux that is reflected from the elliptical mirror and enters the optical fiber, is located between the outer sphere and the inside of the lamp. It is considerably obstructed by the stem etc. Therefore, the elliptical mirror surface behind the lamp is almost ineffective, and the light beam that can enter the optical fiber is only reflected from the periphery of the elliptical mirror, and the light collection efficiency is significantly reduced.

Also, the effective angle of incidence or aperture angle of the optical fiber is approximately 70°.
Therefore, the outer diameter of the elliptical mirror cannot be made too large.

FIG. 2 shows a conventionally known illumination optical device.

At the focal point FI water of the elliptical mirror 1, a light emitting part 3 of a lamp 2, such as a xenon flash, is installed. On the other hand, the end face of the optical fiber 4 is located at the other focal point F2.

The outer diameter of the elliptical mirror 1 is determined to match the angle 0 corresponding to the aperture angle of the optical fiber 4. The light flux 5 (portions indicated by A+, A2, F2) and the solo flux 6 (A:+, All IF2) which pass through the outside of the lamp 2 and directly enter the optical fiber 4 from the elliptical mirror 1 are extremely small as shown in the figure. The reflected light from the portion [Delta]2A of the elliptical mirror 1 which is a small portion and is in the shadow of the outer shape of the lamp 2 rises to the lamp 2 and is blocked. If the concave portion is deepened depending on the eccentricity of the elliptical mirror 1, the amount of light incident on the optical fiber 1 from the outer edge of the elliptical mirror 1 will increase somewhat, but the distance between the elliptical mirror 1 and the light emitting section 3 will increase, and the The dimensions will not fit. Further, it is difficult to manufacture the elliptical mirror 1 with a deep bowl, and it is not practical. Light emitting part 3 or 1", direct optical fiber 4
The amount of light that enters is only a small amount because the color of the body is minute.

-Ta! 1-1 of the present invention:] An object of the present invention is to eliminate the drawbacks of the conventional example and provide an optical fiber illumination optical device having a high light collection efficiency and a convex structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 1. An embodiment of an optical fiber illumination device 1V according to the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of an illumination light device according to the present invention. Note that the same parts as in the conventional example are indicated by the same reference numerals. The elliptical mirror 1 has a deep bowl shape, and a circular hole 6 is provided in the center thereof. Sokeno 1- fixed to case 7
A lamp 2 is inserted in 8, and the lamp 2 is passed through this circular hole 6 from behind the elliptical mirror 1, and is installed so that its light emitting part 3 is located at the focal point 1 of the elliptical mirror 1. . On the other hand, an optical fiber 4 is attached to a boulder 9 fixed to the housing 7.
f' is removed, and its entrance end face is at another focal point F, f! '/,It is location. Optical path 1- between lamp 2 and optical fiber 4, pole 1 fixed to housing 7
0, the lens frame 11 and condensing lens 12 are aligned with the optical axis 1-
The light emitting part 3 is fixedly provided in a hollow space, and the light beam from the light emitting part 3 is condensed onto the optical fiber 4.

Luminous flux emitted from the life sentence light emitting unit 3 of Example] 3 (FI, AI, A2
) and the luminous flux 14 (F, , A3 + A4
) is reflected by the elliptical mirror 1 and enters the optical fiber 4.

In this case as well, the outer diameter of the elliptical mirror 1 is the opening 1-1 of the optical fiber 4.
It is determined to match an angle O (θ to 70°) corresponding to the angle. The light flux that enters the elliptical mirror l from the light emitting unit 3 is directed backward from the light emitting unit 3, whereas the light flux in the conventional example shown in FIG.
In this embodiment, it is a portion in front of the light emitting section 3 1j. This effective angle of incident light (A+FI A2) is much larger than the effective angle (lΔ1FI A2) shown in FIG. 2 in the conventional example. The effective angles shown in the first diagram are all angles on a plane, but in reality these are solid angles, so the difference between them is even greater. In this way, six circular holes are provided in the center of the elliptical mirror 1, which is the shadow part of the lamp 2, and the light beam forward from the light emitting part 3 is used, and it is sent to the elliptical mirror 1, which has a deep recess with a large eccentricity. Since it is reflected, the effective solid angle of the luminous flux becomes large, and the luminous flux is not blocked by the outer wall of the lamp 2 or internal electrode pillars, etc., which has two advantages. If the elliptical mirror 1 and the lamp 2 are arranged as shown in FIG. 1, the lamp 12 and the elliptical mirror 11 will intersect with each other as shown by the dotted line in FIG. In this arrangement, the two must be kept apart. Therefore, if an elliptical mirror with the same eccentricity is used, the focal distance IF2 will be large, and the recess of the elliptical mirror will be correspondingly deeper. Shape of lighting system/
1 method becomes too large, making it difficult to implement. The arrangement as shown in FIG. 1 reduces the dimension of the illumination optical system along the optical axis. Furthermore, since the outer circumference of the elliptical mirror I is significantly closer to the optical fiber 4 than in the arrangement shown in FIG. .

Light ray A2F around the optical axis between lamp 2 and fiber 4
2. In the cone portion surrounded by A and F2, the direct light from the microstar from the light emitting part 3 reaches the optical fiber 4, and is almost an ineffective region. However, a fairly large space is available near the lamp 2. The condensing lens 10 provided at this position allows a beam of light extending at an angle α as shown in the figure to be incident on the optical fiber 4, thereby further improving the condensing efficiency.

Effect---4 pieces Thus, the illumination optical device according to the present invention has a circular shape? L
The elliptical mirror with a deep recess and the lamp arrangement inserted into the circular hole significantly increase the effective luminous flux that is not blocked by the lamp.Furthermore, the condensing I lamp installed on the side of the lamp focuses the light in the center of the optical path. Light can be focused effectively. Therefore, in this illumination solo system, M≦light efficiency is significantly higher than that of conventionally known systems. 1) to create a compact device! The illumination optical system according to the present invention can be expected to find many uses, such as fiber light sources for industrial and medical purposes.

91 Brief Description of Drawings FIG. 1 is a diagram showing an embodiment of an illumination optical device according to the present invention. FIG. 2 is a diagram showing a conventionally known illumination optical device.

Claims (1)

[Claims] In an illumination optical system in which a light source is placed at the focal point of an elliptical mirror and an end face of an optical fiber is placed at the other focal point, an elliptical mirror having a circular hole in the center and a large eccentricity, and a light source passing through the circular hole are used. An illumination optical device consisting of a lamp installed in a lamp, a condensing lens installed on the optical axis between the lamp and an optical fiber, and an optical fiber whose end face is positioned at the focal point.