JP2582599B2 - Light source device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a light source device used for a microscope, an endoscope, an ultraviolet irradiation device, or the like.

[Conventional technology]

A discharge lamp is often used as a built-in lamp in a light source device used for a microscope, an endoscope, and the like. Among discharge lamps, a discharge lamp having a short arc gap such as a xenon short arc lamp, a mercury xenon lamp, an ultra-high pressure mercury lamp, and a metal halide lamp is particularly suitable because of its high brightness and color temperature.

[Problems to be solved by the invention]

However, the discharge lamp having the short arc gap has a problem that it is difficult to condense the light to be emitted to a predetermined diameter or less to increase the light density. In particular, when condensing light from a discharge lamp and trying to guide the condensed light through a fiber, if the fiber diameter is small, only a part of the condensed light is introduced into the fiber, resulting in a loss of light quantity. There was a problem of being big.

An object of the present invention is to provide a light source device capable of condensing light from a discharge lamp having a short arc gap at a high light density and further reducing the loss of light amount even when the fiber diameter is smaller than the converging diameter. And

[Means for solving the problem]

The present invention includes a discharge lamp having a short arc gap, an elliptical reflector for reflecting and condensing light from the discharge lamp, and a fiber unit for guiding the condensed light, wherein the discharge lamp is The incident end of the fiber portion is disposed near a first focal point of an ellipsoid forming an outline of the surface reflecting mirror.
A light source device disposed near the second focal point of the elliptical surface, wherein the fiber portion has a fiber main body and a tapered portion located on the incident end side and connected to the fiber main body. Thus, the above-mentioned problems of the prior art are improved.

[Action]

In the present invention, light from a discharge lamp having a short arc gap is reflected by an ellipsoidal reflecting mirror, condensed, and made incident on a fiber portion.

At this time, the first of the elliptical surfaces forming the contour of the elliptical reflecting mirror
When the discharge lamp is arranged near the focal point, the light from the discharge lamp is condensed by the ellipsoidal reflecting mirror at a high light density, that is, with a small condensing diameter near the second focal point on the elliptical surface. Therefore, by arranging the fiber portion in the vicinity of the second focal point, it is possible to cause the condensed light to be incident on the fiber portion with a small light amount loss. Further, since the tapered portion is provided on the incident side of the fiber portion, even when the diameter of the fiber main body is smaller than the converging diameter, the loss of the light amount accompanying the diameter can be reduced.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram of an embodiment of a light source device according to the present invention. The light source device of the present embodiment includes a discharge lamp 1, a reflector 2 for condensing light from the discharge lamp 1, and a fiber unit 3 for guiding the condensed light. The discharge lamp 1 has an anode 4 and a cathode 5 opposed to each other via a short arc gap 6. By applying a predetermined voltage between the anode 4 and the cathode 5, the discharge lamp 1 discharges light to emit light. It is made to let.

As the reflecting mirror 2, an elliptical reflecting mirror suitable for condensing light from each position of the short arc gap 6 of the discharge lamp 1 is used.

As shown in FIG. 2, the fiber section 3 has a tapered section 7 on the incident side of the collected light. The tapered portion 7 comprises a tapered portion or tapered fiber 8 and a skin 10 surrounding it. The outer skin 10 is made of, for example, stainless steel. Further, the tapered fiber 8 has an incident end 8a.
Is larger than the diameter of the emission end 8b, and is attached to the fiber main body 9 or formed integrally with the fiber main body 9. The fiber body 9 and the tapered fiber 8 may be a bundle of a plurality of fibers, or may be a single fiber.

The discharge lamp 1, the reflecting mirror 2 and the fiber section 3 are arranged as shown in FIG.

That is, the discharge lamp 1 is arranged such that the cathode 5 is located near the first focal point F1 on the elliptical surface of the reflecting mirror 2, and the fiber portion 3 is arranged near the second focal point F2 on the elliptical surface of the reflecting mirror 2. Is done.

With this arrangement, the light from the short arc gap 6 of the discharge lamp 1 is reflected by the reflecting mirror 2 and is concentrated at a high density on the second focal point F2.

For example, the diameter of the reflector 2 is about 76 mm, the length d of the short arc gap 6 of the discharge lamp 1 is 1.3 mm, and the center C of the reflector 2 is
The distance x from the center to the discharge lamp 1 is 13.5 mm, the distance y from the center C to the second focal point F2 is 120 mm, and the fiber section 3 from the second focal point F2.
When the distance z to the incident end of the optical fiber 3 is 5 mm, the light condensing diameter at the incident end of the fiber portion 3 can be made as small as about 2 mm to 3 mm.

Further, in the light source device of the present embodiment, since the incident side of the fiber portion 3 is a tapered fiber 8, even when the diameter of the fiber main body 9 is smaller than the light converging diameter, the condensed light is transmitted through the fiber. The loss of the amount of light when guiding by the unit 3 can be reduced.

For example, a 75 W xenon Schart arc lamp is used as the discharge lamp 1, and a visible light reflecting cold reflector having a diameter of 76 mm is used as the reflecting mirror 2 so that the condensing diameter becomes 3 mm. When the above condensed light was incident, the amount of light guided by the fiber bundle was 90,000 lux on average. On the other hand, when the light condensed under the same conditions enters the fiber section 3 of the present embodiment (the input end 8a and the output end 8b of the tapered fiber 8).
Were 3 mm and 1 mm, respectively, and the diameter of the fiber body 9 was 1 mm. ), The amount of light guided by the fiber body 9 was 140,000 lux on average. Therefore, by attaching the tapered fiber 8 to the fiber main body 9, the loss of the light amount can be reduced.

Further, by providing the tapered fiber 8, the optical axis alignment at the time of replacing the lamp or the like becomes remarkably easy as compared with the related art. That is, conventionally, the condensed light is directly incident on the fiber portion where the tapered fiber 8 is not provided, so that it is very difficult to align the optical axis when the fiber is thin. For this reason, the optical axis alignment is performed by a method in which the condensed light is incident on the fiber in a defocused state, and there is a disadvantage that the optical axis cannot be aligned with high accuracy. On the other hand, in the present embodiment, even if the optical axis is slightly deviated, the loss of the light amount is small due to the tapered fiber 8, so that the optical axis can be accurately and easily adjusted without defocusing the collected light. Can be performed.

〔The invention's effect〕

As described above, in the present invention, the discharge end of the discharge lamp and the fiber section is defined by the first elliptical surface forming the contour of the elliptical reflector.
Since they are arranged near the focal point and near the second focal point, respectively, the light from the discharge lamp can be collected with a high light density, that is, with a small light collecting diameter. Further, since the tapered portion is provided on the incident end side of the fiber portion, even when the fiber diameter is smaller than the converging diameter, the loss of the light amount can be reduced.

[Brief description of the drawings]

FIG. 1 is a structural view of an embodiment of a light source device according to the present invention, and FIG.
FIG. 3 is a sectional view of the tapered portion, and FIG. 3 is a diagram for explaining a mutual positional relationship between the discharge lamp, the reflecting mirror, and the fiber portion. 1 discharge lamp, 2 reflecting mirror, 3 fiber section, 6 short arc gap, 7 taper section, 8 tapered fiber, 8a entrance end, 9 fiber body

Claims (1)

(57) [Claims] A discharge lamp having a short arc gap between an anode and a cathode; an elliptical reflector for reflecting and condensing light from the discharge lamp; and a fiber section for guiding the condensed light. An end face of a cathode of the discharge lamp is disposed near a first focal point of an ellipsoid forming an outline of the ellipsoidal reflecting mirror;
In this case, on the line connecting the light incident end of the fiber portion and the center of the discharge lamp, the light source device in which the cathode and the anode are arranged in order from the incident end of the fiber portion, The entrance end is disposed at a predetermined position farther from the second focal point of the ellipsoid forming the contour of the ellipsoidal reflection mirror to the opposite side to the reflection mirror, and the fiber section includes a fiber main body and an entrance end side. And a taper portion connected to the fiber main body, wherein the diameter of the incident end face of the taper portion is larger than the diameter of the fiber main body.