JPH07209583A - Light converging device for optical fiber projection light - Google Patents

Abstract

PURPOSE:To converge projection light with high density and obtain a space which facilitates various operations nearby the convergence point by using a reflecting mirror which consists of part of a revolutional elliptic mirror and projecting the projection light from an optical fiber or fiber bundle on the reflecting mirror from a 1st focus. CONSTITUTION:This device consists of a light source 5, the optical fiber bundle (or optical fiber) 6, the reflecting mirror 7a consisting of part of a revolutional elliptic reflecting surface, and an irradiated surface 8. Not the whole, but part of the revolutional elliptic mirror is used as the reflecting mirror. In this case, an optical path and a reflected light path are nearly equal, so the area of the projection end of the optical fiber 6 positioned at the 1st focus F1 is nearly maintained at a 2nd focus F2. (Strictly speaking, an image formed at the 2nd focus F2 is out of focus since the projection end is not a spot.) Therefore, the 2nd focus F2 of the reflecting mirror is at the position, so converged light energy with high density is obtained. Further, a large spatial work area can be obtained nearby the 2nd focus F2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the collection of light emitted from an optical fiber in, for example, an illuminating device for a high-power microscope or a high-speed camera, a light irradiation device for photopolymerization, a light heating device used for optical soldering, or the like. The present invention relates to an optical device.

[0002]

2. Description of the Related Art Conventionally, there are a light source lamp using a condenser lens and a spheroidal mirror as a condenser.

However, when a condenser lens is used as a condenser for the light emitted from the optical fiber or the optical fiber bundle,
When the optical fiber 1 is arranged at the focal point of the lens 2 as shown in FIG. 1A, the light emitted from the optical fiber 1 is originally a diffused light, and the light collection efficiency is poor. Further, as shown in FIG. 1B, when the optical fiber 1 is moved away from the focus, the light collection efficiency increases and the density becomes relatively high. Required, and the working distance (WD) becomes extremely short, and the work area becomes narrow.

On the other hand, as shown in FIG. 1C, the spheroidal mirror 3
In the method using, the weak light on the outer side close to the aperture angle is condensed, but the strong light in the vicinity of the center is not condensed, resulting in light loss.

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention provides an optical fiber which collects light emitted from an optical fiber or an optical fiber bundle at a high density and provides a space near the condensing point to facilitate various operations. An object of the present invention is to provide a condensing device for emitted light.

[0006]

The present invention has been made to solve the above-mentioned problems, and uses a reflecting mirror which is a part of a spheroidal mirror, and an optical fiber from the first focal point toward the reflecting mirror. Alternatively, the light emitted from the optical fiber bundle is projected.

The difference between the present invention and the conventional light collecting device in which the light source lamp is provided at the first focal point of the spheroidal mirror is not the technical idea of using the entire spheroidal mirror as the reflecting surface, but FIG.
That is to use a part as shown in.

In FIG. 2, reference numeral 1 is an optical fiber or an optical fiber bundle, and 4 is a reflecting mirror which is a part of a spheroidal mirror.
F ₁ is the first focus, F ₂ is the second focus, and WD is the working distance.

It is well known in FIG. 3 that when a point light source is placed at the first focal point F ₁ of a spheroidal mirror R having an inner surface as a mirror surface, all light rays are reflected by the inner surface and are condensed at a second focal point. As described above, when the point light source placed at the first focus F ₁ has a certain size, the image is formed near the second focus F _2, but the same image as the point light source cannot be formed.

[0010]

[Outer 1]

Therefore, in the case of FIG. 3, the images reflected at P ₁ and P ₂ are large at the second focal point F ₂ , and the images reflected at P _n-1 and P _n have almost the same magnification. As a result of the superposition, the image at the second focus F ₂ becomes blurry.
In the case of FIG. 3, the blur of the image is large, that is, the density is low.

From the above, it is advantageous to minimize the light spot in order to effectively collect light using the reflecting mirror which is a part of the spheroidal mirror.

[0013]

[Outside 2]

Therefore, when there is only one light source, an optical fiber bundle is used, one end of which is opposed to the light source and the other end is branched into a plurality of optical fibers.
The optical system as shown in Fig. 2 is configured and the reflecting mirrors are arranged so that the second focal points of the respective reflecting mirrors are at the same position, or plural optical systems shown in Fig. 2 each having a light source are arranged and each reflecting By configuring the second focal point of the mirror to be at the same position, a high density of condensed light energy can be obtained.

Since the light emitted from the optical fiber 1 is not emitted in all directions unlike a point light source but has a constant solid angle (usually 20 ° to 70 °), the size of the reflecting mirror 4 is large. It only needs to be large enough to receive the light. And
The working distance WD changes depending on the position where the reflecting mirror 4 is provided, and as described above, when the position of the reflecting mirror 4 is close to the second focal point F ₂ , the light condensing density becomes large (the image area becomes small). Since it will be smaller, it is necessary to consider the trade-off in the implementation.

[0016]

FIG. 4 shows a first embodiment of the present invention, 5 is a light source, 6 is an optical fiber bundle (or optical fiber),
Reflector consisting of part of the spheroidal reflecting surface 7a, 8 are irradiated surface, F ₁ is the first focal point of the spheroid, F ₂ is the second focal point.

[0017]

[Outside 3]

In this embodiment, a large spatial work area can be taken near the second focal point.

[0019]

[Outside 4]

FIG. 6 shows a third embodiment of the present invention, and there is no problem even if the surface 8 to be irradiated is a flat surface and is covered with a reflecting mirror 7c as in the case of irradiating the end portion. This is the case.

[0021]

[Outside 5]

FIG. 7 shows a fourth embodiment of the present invention. An optical fiber bundle 6 is branched and a reflecting mirror 7 according to the present invention is used for each optical fiber. The reflecting mirrors are arranged so as to be at the same position.

In this case, if the incident end area of the optical fiber bundle 6 that receives the light from the light source 5 is S ₀ and the number of branches is n, the area Sn of the optical fiber exit end is

[0024]

[Equation 1]

[0025] As can be seen from equation (3),
The larger the number of branches n and the smaller the optical path ratio m, the more the light collecting area Sm.
Can be reduced.

Further, in the second focal point F _2, it means that superimposed the n number of the reflected light, the light energy that is input to the entrance end S ₀ is the focal point, i.e. the condenser at the second focal point F ₂ To be done. For example, assuming that the optical fiber bundle 6 has eight branches and the optical path ratio m on the spheroid is 2,

[0027]

[Equation 2]

FIG. 8 shows a fifth embodiment of the present invention, which is a modification of the fourth embodiment shown in FIG. In this case, the holders (not shown) for the reflecting mirrors 7, 7 are the fourth
It can be made smaller than that of the embodiment. In this embodiment, the reflecting mirrors 7 and 7 are opposed to each other, and the holes 7d and 7d for emitting the light emitted from the optical fiber are provided respectively, but if the reflecting mirrors are provided not to face each other but to be shifted, the holes are provided. It will be unnecessary.

FIG. 9 shows a sixth embodiment of the present invention, in which n reflection mirrors 7 are provided on a holding body 9 in the form of a shade, and 6a is a light output of a branched optical fiber. At the end, the light can be condensed with high density at the position of the second focus F ₂ .

[0030]

EFFECTS OF THE INVENTION It is possible to provide a light irradiation device using an optical fiber or an optical fiber bundle capable of obtaining a high density of condensed light energy and having a large working distance.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a problem of a light collecting device according to a conventional method.

FIG. 2 is a principle view of the present invention.

FIG. 3 is an explanatory diagram of points to be considered when implementing the present invention.

FIG. 4 is a schematic diagram showing the configuration of the first exemplary embodiment.

FIG. 5 is a schematic diagram showing a configuration of a second exemplary embodiment.

FIG. 6 is a schematic diagram showing a configuration of a third exemplary embodiment.

FIG. 7 is a schematic diagram showing a configuration of a fourth exemplary embodiment.

FIG. 8 is a schematic diagram showing a configuration of a fifth exemplary embodiment.

FIG. 9 is a schematic diagram showing a configuration of a sixth exemplary embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 optical fiber 2 lens 3 spheroidal mirror 4 reflecting mirror 5 light source 6 optical fiber bundle 7, 7a to 7c reflecting mirror 8 irradiated surface 9 holder

Claims (2)

[Claims] 1. A reflecting mirror, which is a part of a spheroidal mirror, is used as the reflecting mirror, and light emitted from an optical fiber or a bundle of optical fibers is projected from the first focal point toward the reflecting mirror and is condensed at the second focal point. A condensing device for light emitted from an optical fiber. 2. A plurality of reflecting mirrors each of which is a part of a spheroidal mirror are used, and a light emitting end of an optical fiber or a bundle of optical fibers is arranged at a first focal point of each reflecting mirror to face each reflecting mirror. A condensing device for emitted light from an optical fiber, characterized in that each reflecting mirror is arranged such that the emitted light is projected and the second focus of each of the reflecting mirrors is at the same position.