JPH03287112A - Irradiation device for optical fiber - Google Patents

Abstract

PURPOSE:To suppress decreases in the color temperatures and color rendering evaluation numbers of optical fiber incident light and projection light by providing an optical fiber whose incidence end surface is positioned at the light convergence part of a reflecting mirror and using a high pressure sodium lamp as a light source. CONSTITUTION:The reflecting mirror 10 absorbs infrared rays emitted by the high pressure sodium lamp 2 and reflects visible light and the optical fiber 12, on the other hand, is fitted to an optical fiber support 16 fixed to a base 6 so that the incidence end surface is positioned at the convergence part of the reflecting mirror 1. The relative spectral energy distribution of the high pressure sodium lamp 2 is lower in relative spectral energy in both the ultrashort wavelength range and long wavelength range than other wavelength ranges. The light incident on the optical fiber from the high pressure sodium lamp 2 which is low in light transmissivity in the ultrashort wavelength range and long wavelength range is projected from the projection end surface of the optical fiber without being attenuated only in a specific wavelength range. Consequently, the projection light of the optical fiber 12 is improved in color temperature and color rendering evaluation number as compared with the incident light.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an optical fiber irradiation device used for, for example, downlights and spotlights.

(Prior Art) In general, an optical fiber irradiation device makes direct light emitted from a light source and reflected light reflected and condensed by a reflecting mirror enter the input end face of an optical fiber, and directs the incident light to the optical fiber. A configuration is adopted in which the light is guided as illumination light from the output end face of the optical fiber.

(Problem to be solved by the invention) Most of the conventional optical fiber irradiation devices mentioned above use a halogen lamp as a light source, and the light emitted from this light source is guided through an optical fiber molded from synthetic resin. .

For example, a halogen lamp is used as the light source, and the optical fiber is made of acrylic resin with a diameter of 0.5 mm and a length of 5 m.
A case will be explained in which the wave is guided through an optical fiber and is emitted as illumination light. In this case, the spectral transmittance of the optical fiber is as shown in Figure 4, and the relative spectral energy distribution of the halogen lamp is as shown in Figure 5.
This halogen lamp has continuous spectral energy in the wavelength path range of 400 to 700 nm, but on the other hand, this optical fiber has a short wavelength range (approximately 400 to 400 nm) that shows blue color.
8Onm range) and a long wavelength range showing red (approximately 680~70nm range)
0 nm range), the transmittance of both is extremely low, and compared to the incident light, the spectral energy of the output light of the halogen lamp is absorbed considerably, especially in the short wavelength range and long wavelength range. As shown, a problem arises in that both the color rendering index and the color temperature decrease.

Table 1 Furthermore, since the light emitted from an optical fiber using a halogen lamp as a light source has a yellowish tinge, Japanese people in particular tend to avoid it.

In order to solve the above-mentioned problems, an object of the present invention is to provide an optical fiber irradiation device that suppresses a decrease in color temperature and color rendering index of human light and emitted light from an optical fiber, and suppresses yellowish tinge of light emitted from an optical fiber. It's about doing.

[Structure of investigation]

(Means for Solving the Problems) The optical fiber irradiation device of the present invention includes a light source, a reflecting mirror disposed optically facing the light source, and an incident end face located in the condensing part of the reflecting mirror. equipped with an optical fiber,
The light source is a high pressure sodium lamp.

(Function) The optical fiber irradiation device of the present invention uses a high-pressure sodium lamp as a light source, and condenses the direct light emitted from the high-pressure sodium lamp and the reflected light reflected by a reflecting mirror. A lighting effect is obtained by inputting light into the input end face of an optical fiber, guiding the incident light through the optical fiber, and irradiating it as illumination light from the output end face of the optical fiber.

The relative spectral energy distribution of this high-pressure sodium lamp is as shown in Figure 3.
80 nm region) and long wavelength region (approximately 680 to 700 nm region)
Since both of the relative spectral energy in the short and long wavelength ranges are low compared to the relative spectral energy in the other wavelength ranges, the incident light from the high-pressure sodium lamp that enters the optical fiber has low light transmittance in the short wavelength range and the long wavelength range. Only a specific wavelength range is irradiated from the output end face of the optical fiber without being selectively attenuated.

Therefore, the color rendering index and color temperature of the incident light entering the optical fiber and the output light irradiated from the optical fiber hardly change, and a calm atmosphere of illumination light can be obtained by the light of the high-pressure sodium lamp.

Furthermore, since the relative spectral energy of the short wavelength region and the long wavelength region of this high-pressure sodium lamp is low, deterioration of the input end face of the optical fiber due to ultraviolet rays and heat is also reduced.

(Example) An example of the present invention will be described with reference to FIGS. 1 and 2.

In FIG. 1, 1 is an irradiation unit of an optical fiber irradiation device, and this irradiation unit 1 has a high-pressure sodium lamp 2 serving as a light source.
To attach the lamp socket 3 to which the lamp socket 3 is detachably attached, a plurality of screw rods 5 are provided protruding from the base plate 4, and these screw rods 5 are attached to the base 6
The lamp socket 3 is supported on the support body 7 by a nut 8 which is inserted into the lamp support body 7 fixed to the lamp support body 7 so as to be movable back and forth, and which is screwed into the screw rod 5 . The lamp socket 3 is urged forward by the coil spring 9 wound around the screw rod 5 around the base plate 4 and lamp support 7 of the lamp socket 3, and the high pressure sodium lamp 2 is pushed forward by adjusting the nut 8. The focus is now adjusted.

Reference numeral 10 denotes a reflecting mirror, which has an appropriate shape such as a paraboloid of revolution containing the high-pressure sodium lamp 2 or an elliptical cross-sectional shape extending in the elongated direction, and is fixed to the base 6 with a reflecting mirror support. It is supported by the body 11. The reflecting mirror 10 is composed of an infrared absorbing reflector that absorbs infrared rays and reflects visible light emitted from the high-pressure sodium lamp 2, or an infrared transmitting reflector that transmits infrared rays and reflects visible light.

Next, reference numeral 12 denotes an optical fiber that guides the direct light from the high-pressure sodium lamp 2 and the reflected light from the reflecting mirror 10, and is made of acrylic resin or the like.
The incident end side of is introduced into the irradiation unit 1 through the optical fiber insertion hole 13 on one end surface of the irradiation unit I, fitted into the optical fiber socket 14 and held by a screw 15,
The incident end face of the optical fiber 12 is attached to an optical fiber support 16 fixed to the base 6 so as to be located at the condensing portion of the reflecting mirror 10.

Further, on the surface of the support 16 of the optical fiber 12 facing the high pressure sodium lamp 2, the optical fiber 1
A filter 17 is disposed between the incident end face of the high-pressure sodium lamp 2 and the reflecting mirror 10 and blocks the transmission of direct light from the high-pressure sodium lamp 2 and heat rays included in the reflected light from the reflecting mirror 10. There is. This filter 17 is formed with, for example, an interference film that reflects infrared rays and transmits visible light, or an interference film that has an infrared absorbing layer and absorbs infrared rays and transmits visible light. The filter 17 is detachably attached to the optical fiber support 16 with a screw 18 while maintaining a gap between the incident end face of the optical fiber 12 and the input end face of the optical fiber 12 using a fitting 19.

In this way, the high pressure sodium lamp 2, reflector 10, filter 17 and optical fiber 12 are mounted on the base 6 with their center heights aligned in a straight line.

In FIG. 2, 2(l) is a lighting unit, and this lighting unit 20 is connected to an electric wire 21 connected to the lamp socket 3 of the irradiation unit 1, which is a device consisting of a choke coil, a resistor, etc. It is housed in a housing 22 together with the unit 1. Also, the optical fiber 12 is
is led out of the housing 22 and is disposed up to the output end surface 26 of the optical fiber 12 provided on the ceiling surface 25 or the like.

Next, the operation of this embodiment will be explained.

When the high-pressure sodium lamp 2 is turned on, the direct light emitted from the high-pressure sodium lamp 2 passes through the filter 7 disposed near the condensing part of the reflector 10 and enters the input end face of the optical fiber 12. The reflected light reflected by the reflecting mirror 10 is incident on the input end face of the optical fiber 12 via the filter 17, and the visible light incident on the optical fiber 12 is guided by the optical fiber 12, and is illuminated from the output end face 26 of the optical fiber 12. It is irradiated as light.

The light emitted by this high-pressure sodium lamp 2 is generally in a short wavelength range (approximately 400 nm
~480nm region) and long wavelength region (approximately 680 to 700nm region), the relative spectral energy is small compared to other wavelength regions, so the optical fiber 12 (optical fiber Diameter 0.5m
m, optical fiber length 5m) and high pressure sodium lamp 20
When incident light is made incident, only a specific wavelength of this incident light is not selectively attenuated and is emitted as illumination light from the output end face of the optical fiber.

Therefore, as shown in Table 2, the input light and the output light of the optical fiber 12 can reduce the decrease in color temperature and decrease in color rendering index compared to the case of the halogen lamp shown in Table 1. Far from suppressing it, it can actually be improved and improved.

Table 2 (Optical fiber length 5m, φ0.5mm) In addition, the color temperature of the light emitted by the high-pressure sodium lamp is lower than that of the light emitted by the halogen lamp, so the light from the high-pressure sodium lamp is calm. It becomes the light of the atmosphere, and
This results in illumination light that does not have a yellowish tinge.

Furthermore, since the light from the high-pressure sodium lamp 2 has low spectral energy in the short and long wavelength ranges, deterioration of the incident end face of the optical fiber 12 due to ultraviolet rays and heat can be reduced.

0 In the above embodiment, three optical fiber irradiation devices are housed in the housing 22, but the present invention is not limited to this, and it is also possible to house one or more optical fiber irradiation devices.

〔Effect of the invention〕

According to the present invention, since a high-pressure sodium lamp with low relative spectral energy in the short wavelength range and long wavelength range is used as the light source, the light source is connected to the light source using an optical fiber with low transmittance in the short wavelength range and long wavelength range. Even when the emitted light is guided and irradiated, it is possible to suppress a decrease in the color temperature of the light emitted from the optical fiber compared to the light incident on the optical fiber, and the color rendering index is improved.

Furthermore, since the color temperature of the light source is originally low, illumination light with a calm atmosphere without yellowing can be obtained.

Furthermore, since the relative spectral energy of the high-pressure sodium lamp in the short wavelength region and the long wavelength region is small, deterioration of the optical fiber input end face due to ultraviolet rays and heat can be reduced.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of an irradiation unit of an optical fiber irradiation device showing an embodiment of the present invention, Fig. 2 is a constituent country of the above optical fiber irradiation device, and Fig. 3 is a distribution diagram of relative spectral energy of the same high-pressure sodium lamp. FIG. 4 is a distribution diagram of spectral transmittance of the same optical fiber, and FIG. 5 is a distribution diagram of relative spectral energy of a halogen lamp, which is an example of the conventional lamp. 2. High pressure sodium lamp, 10. Reflector, 12.
・Optical fiber 1 ↑ 2

Claims (1)

[Claims] (1) A light source, a reflecting mirror disposed optically opposite to the light source, and an optical fiber having an incident end face located in a condensing portion of the reflecting mirror, wherein the light source is a high-pressure natrium lamp. An optical fiber irradiation device characterized by: