JPH04332458A - Lighting system - Google Patents

Abstract

PURPOSE:To prevent lowering of luminous intensity distribution characteristics and temperature rise in a connecting part between a metallic foil electric conductor and an outside lead wire by reducing reflection of light or absorption of heat by the metallic foil electric conductor sealed up in a sealing part of an electric discharge lamp in a lighting system constituted by combining this lamp and a reflecting mirror together while using a small metallic vapor electric discharge lamp as a light source. CONSTITUTION:A flat surface of a metallic foil electric conductor 13 sealed up in a sealing part 12 of a metallic vapor electric discharge lamp 10 is arranged so as to face in the parallel direction to the optical axial direction of a reflecting mirror 5. Light or heat reflected on the reflecting surface of the reflecting mirror passes through in the parallel direction to a wide flat surface of the metallic foil electric conductor, so that proportion of the light or the heat incident upon the flat surface of the metallic electric conductor can be reduced.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination device which uses a small metal vapor discharge lamp such as a small metal halide lamp as a light source and is constructed by combining this lamp with a reflecting mirror.

0002

[Prior Art] A condensing irradiation device that intensively irradiates a predetermined area is used as a lighting device to illuminate roads, plazas, stadiums, baseball stadiums, etc. This device uses a lamp as a light source and a reflector. In combination, it forms a structure similar to a floodlight.

[0003] It is desirable that the lamp used as a light source be small and have a high light output, and for this reason short arc metal halide lamps have recently been used.

[0004] Short arc type metal halide lamps are formed by extending sealing parts at both ends of an arc tube bulb made of transparent quartz glass, and sealing metal foil conductors such as molybdenum into these sealing parts. It has been done. Electrode shafts are welded to these metal foil conductors, and electrode coils are attached to the tips of these electrode shafts. therefore,
The electrode coils are spaced apart and opposed to each other inside the bulb.

Further, external lead wires are welded to each of these metal foil conductors, and these external lead wires are led out from the tip of the sealing portion.

A short-arc metal halide lamp having such a configuration is housed in a reflecting mirror having a curved surface like a paraboloid of revolution, and in this case, the extension direction of the sealing part of the lamp, that is, the lamp axis, It is attached to the reflector in a position perpendicular to the optical axis of the mirror.

In such a lighting device, when a power supply voltage is applied between the electrodes through the external lead wire of the lamp, a discharge occurs between these electrodes, and the metal halide sealed within the bulb emits light. This light is emitted from the bulb, reflected by the reflector, and emitted in front of the lamp. Therefore, a predetermined area in front is irradiated.

[0008] The metal halide lamp used as the light source has superior luminous efficiency compared to incandescent light bulbs, has better color rendering properties and longer life characteristics, and has a smaller bulb because it does not use an outer tube to cover the bulb. Therefore, it becomes close to a point light source, and this type of illumination device has advantages such as excellent light gathering ability and can be constructed in a small and compact size.

However, since this type of lamp has a high output, the temperature of the sealing part becomes high while it is lit, which causes the joint between the metal foil conductor and the external lead wire to become hot, and this joint becomes oxidized. This joint may peel off, melt, or
There is a concern that cracks may occur at the tip of the sealing part. In order to prevent this, the length of the sealing portion is made relatively long.

[0010] Furthermore, the metal foil conductor sealed in such a sealing part requires a certain width in order to pass a predetermined large current. It must be relatively large.

[0011]

[Problems to be Solved by the Invention] However, such a metal foil conductor reflects and absorbs more light than the quartz glass that forms the sealing part, and as mentioned above, metal foil conductors with a large area The amount of reflection from the foil conductor is large, and the temperature tends to rise due to radiant heat.

However, in the conventional case, the metal foil conductor was disposed so as to face the reflecting surface of the reflecting mirror. That is, the flat surface of the metal foil conductor sealed to the sealing portion was arranged to intersect with the optical axis direction of the reflecting mirror.

[0013] Therefore, the light emitted from the lamp and reflected by the reflective surface hits the wide surface of the metal foil conductor, and a large amount of light is reflected from this surface, and this reflected light heads in an undesired direction. There is a problem that the light collection characteristics deteriorate because it disturbs the normal light distribution.

[0014] In addition, in the case of such a mounting posture, the radiant heat reflected by the reflective surface hits the wide surface of the metal foil conductor, increasing the temperature of the metal foil conductor, which causes the metal foil conductor and the external lead wire to The joints become hot, and are likely to oxidize, causing concerns such as peeling of the joints and cracks in the sealing parts.

The present invention was made based on the above circumstances, and its purpose is to reduce reflection and heat absorption by the metal foil conductor sealed in the sealing part, and to prevent deterioration of light distribution characteristics and It is an object of the present invention to provide a lighting device that can prevent a rise in temperature at the joint between a metal foil conductor and an external lead wire.

[0016]

[Means for Solving the Problems] The present invention provides a metal vapor discharge lamp arranged such that the flat surface of the metal foil conductor sealed in the sealing portion is oriented parallel to the optical axis direction of the reflecting mirror. It is characterized by

[0017]

[Operation] According to the present invention, since the flat surface of the metal foil conductor is arranged parallel to the optical axis direction of the reflecting mirror, the light reflected by the reflective surface is transmitted to the wide flat surface of the metal foil conductor. The light passes in parallel and the proportion of light incident on the flat surface of the metal foil conductor is reduced. Therefore, the light reflected by this metal foil conductor is reduced,
This eliminates the possibility of disturbing normal reflected light. Further, the radiant heat absorbed by the reflective surface also passes parallel to the metal foil conductor, and the proportion of the radiation that enters the flat surface of the metal foil conductor is reduced, making it possible to prevent the temperature of the metal foil conductor from rising.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below based on an embodiment shown in the drawings.

In the figure, 1 is a lamp, and a housing 2
and a lens 3 which also serves as a front cover. The housing 2 is made of metal such as stainless steel, and has a curved surface such as a paraboloid of revolution with an open front surface. The lens 3 is attached to this front surface. This lamp 1 houses a reflecting mirror 5 and a lamp 10 as a light source.

The reflecting mirror 5 is made of a bright metal such as stainless steel or aluminum, and has a curved surface such as a paraboloid of revolution with an open front surface.

The lamp 10 is made of, for example, a short arc metal halide lamp, and is placed at a predetermined position of the reflecting mirror 5.

[0022] Regarding the lamp 10, 11 is an arc tube bulb made of transparent quartz glass. This bulb 11 has a substantially elliptical shape, and for example, in a lamp with a rated output of 2KW, the outer diameter in the long axis direction is 50m.
m, and the outer diameter in the minor axis direction is approximately 40 mm.

Sealing portions 1 are provided at both ends of the valve 11, respectively.
2 and 12 are formed, and these sealing parts 12 and 12 extend from both ends of the bulb 11 along the lamp axis direction O2 - O2.

Metal foil conductors 13, 13 made of molybdenum or the like are sealed to these sealing parts 12, 12. Electrode shafts 15, 15 made of tungsten that constitute the electrodes 14, 14 are welded to these metal foil conductors 13, 13, and electrode coils 16, 16 made of tungsten are attached to the tips of these electrode shafts 15, 15. It is being Therefore, the electrode coils 16, 16 are opposed to each other and spaced apart from each other inside the bulb 11.

External lead wires 17, 17 made of molybdenum or the like are welded to the metal foil conductors 13, 13, respectively.
, 12 are led out from the tips.

Note that 18 is a stay of the reflecting mirror 5.

The bulb 11 is filled with a metal halide such as ScI3 or NaI, mercury, and a starting rare gas such as argon or xenon.

Such a short arc type metal halide lamp 10 is arranged such that the extension direction of the sealing parts 12, 12, that is, the lamp axis O2 - O2 is perpendicular to the optical axis (mirror axis) O1 - O1 of the reflecting mirror 5. Reflector 5 in posture
is attached to.

In this case, the metal foil conductors 13, 13 made of molybdenum have a flat shape with a predetermined length and width, and as shown in FIG.
The optical axis O1 - O1 is arranged so as to be oriented along the optical axis O1 - O1 direction.

In other words, FIG. 3 shows an unfavorable example,
In the case of this defective example, the flat surfaces of the metal foil conductors 13, 13 and the optical axis O1-O1 of the reflecting mirror 5 intersect with each other at an angle θ.

On the other hand, in the case of this embodiment, as shown in FIG. The angle θ is 0.

The operation of the lighting device of this embodiment will be explained.

When a voltage is applied between the electrodes 14, 14 through the external lead wires 17, 17 of the short arc metal halide lamp 10 as a light source, these electrodes 14, 1
After 4 hours, the metal halide emits light.

This light is emitted from the bulb 11, reflected by the reflecting mirror 5, transmitted through the front lens 3 of the lamp 1, and emitted forward, thereby illuminating a predetermined area in front.

In this case, the lamp 10 is located in front of the reflecting surface, and the sealing parts 12, 12 are aligned with the optical axis O of the reflecting mirror 5.
1 -O1, the light reflected by the reflecting mirror 5 and the radiant heat are transmitted to the sealing parts 12, 12.
corresponds to

In this embodiment, as shown in FIG.
The flat surfaces of the metal foil conductors 13 and 13 sealed to the reflector 5 are set in a direction parallel to the optical axis O1 - O1 of the reflector 5, that is, the intersection angle θ is set to 0, so that the metal foil conductors 13 and 13 sealed to the reflector 5 The reflected light passes parallel to the wide flat surfaces of the metal foil conductors 13, 13, and the proportion of the reflected light hitting the flat surfaces of the metal foil conductors 13, 13 is reduced. Therefore, the amount of light reflected by the metal foil conductors 13, 13 is reduced, and normal reflected light is not disturbed. Therefore, light collection characteristics are improved.

Furthermore, the radiant heat reflected by the reflecting mirror 5 rarely hits the metal foil conductors 13, 13, and the metal foil conductors 1
3, 13 temperature rise is prevented. This prevents the joints between the metal foil conductors 13, 13 and the external lead wires 17, 17 from becoming high temperature, causing oxidation of the joints, peeling of the joints, and damage to the sealing portion 12. Problems such as cracks are prevented.

In particular, when the reflecting mirror 5 is made smaller, the aperture diameter becomes smaller and the focal point is located at the inner part, and the lamp 10 is placed close to the top of the reflecting mirror 5, so that the sealing Although the stop portion is likely to receive heat, the above configuration can reduce the effect of heat.

Incidentally, the results of experiments regarding the above embodiment are shown in FIGS. 4 and 5.

FIG. 4 is a characteristic diagram showing the relationship between the crossing angle θ shown in FIG. 3 and the temperature at the junction between the metal foil conductor and the external lead wire. It can be seen that the temperature in the area becomes lower.

FIG. 5 shows the intersection angle θ also shown in FIG.
FIG. 3 is a diagram of light condensing characteristics obtained by examining the light flux φ in a range of a spread angle of 30 degrees from the lamp 1. FIG. It is confirmed that the closer the intersection angle θ is to 0, the more the luminous flux φ increases, and the better the light focusing ability becomes.

In the present invention, the lamp used as a light source is not limited to a metal halide lamp, but may be a high-pressure mercury lamp.

Furthermore, the lighting device of the present invention is not limited to the above-described embodiments in that it includes a lamp and the structure of the lamp.

[0044]

As explained above, according to the present invention, the flat surface of the metal foil conductor sealed in the sealing portion is set in a direction parallel to the optical axis of the reflecting mirror. The proportion of light reflected by the metal foil conductor hitting the wide flat surface of the metal foil conductor is reduced. Therefore, this metal foil conductor reflects less light, and normal reflected light is not disturbed. Therefore, light collection characteristics are improved. Furthermore, the radiant heat reflected by the reflecting mirror is less likely to hit the metal foil conductor, thereby preventing the temperature of the metal foil conductor from rising. Therefore, the metal foil conductor and external lead
This prevents the bonded portion of the wire from becoming high temperature, and prevents problems such as oxidation of the bonded portion, peeling of the bonded portion, and cracks in the sealing portion.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a lighting device showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1.

FIG. 3 is a sectional view showing an unfavorable example.

FIG. 4: Temperature characteristic diagram.

FIG. 5 is a characteristic diagram of luminous flux.

[Explanation of symbols]

1... Lamp, 5... Reflector, 10... Metal halide lamp,
DESCRIPTION OF SYMBOLS 11... Bulb, 12... Sealing part, 13... Metal foil conductor, 14
...electrode, 17...external lead wire.

Claims (1)

[Claims] Claim 1: A metal vapor discharge lamp is housed in a reflecting mirror consisting of a curved surface with an open front surface, and the metal vapor discharge lamp has electrodes sealed within the bulb and sealing parts extending to both ends of the bulb. A metal foil conductor connected to the electrode is sealed to this sealing portion, and an external lead wire connected to the metal foil conductor is led out from this sealing portion. In a lighting device in which the lamp axis of the electric light is arranged to intersect with the mirror axis of the reflecting mirror, the metal vapor discharge lamp has a flat surface of the metal foil conductor sealed to the sealing part in the direction of the optical axis of the reflecting mirror. A lighting device characterized in that it is arranged so as to be oriented parallel to.