JPH07335181A - Metal halide lamp device - Google Patents

Abstract

PURPOSE:To provide a projection metal halide lamp device which has a long lifetime and is constructed compactly. CONSTITUTION:A metal halide lamp device includes a light emitting tube 1 consisting of a light emission part 1a and sealed attachment parts 3a, 3b furnished at both ends of the part 1a and a reflex mirror 7. Metal foils 4a, 4b of molybdene are attached sealedly to these sealed attachment parts 3a, 3b. Electrodes 2a, 2b are connected with one-side ends of the metal foils 4a, 4b while one-side ends of external conductors 5a, 5b are connected with the other ends of the metal foils 4a, 4b so that a connection part 13 is formed. The other ends of the external conductors 5a, 5b are led out from the end faces of the sealed attachment parts 3a, 3b. This light emitting tube 1 is installed inside the reflex mirror 7 in such a way as directed perpendicularly to the axis of the reflex mirror 7 and so that the connection part 13 in the parts 3a, 3b is positioned outside the reflex mirror 7. A fan 10 is installed on the counter- reflection side of the mirror 7. Accordingly an oxidative fusion cut of the connection part of metal foil with external conductor can be suppressed without prolonging the sealed attachment parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type metal halide lamp device for a liquid crystal projector, a slide projector or the like.

[0002]

2. Description of the Related Art A metal halide lamp utilizes a phenomenon in which a metal halide enclosed in an arc tube evaporates while the lamp is lit, and metal atoms are excited to emit light in a high temperature arc. Therefore, by selecting the metal halide to be enclosed, a lamp with high efficiency and high color rendering with an arbitrary light color is possible. It is also possible to bring it closer to a point light source by shortening the distance between the electrodes, so-called short arc.
By incorporating a metal halide lamp with a short arc into the reflecting mirror, a light source with high light collection efficiency can be obtained. Due to such characteristics, in recent years, a short arc type metal halide lamp has been combined with a reflecting mirror and used as a backlight light source of a projection type liquid crystal video projector or the like.

[0003]

Since the metal halide lamp device used in such a liquid crystal video projector is required to be compact, a single tube type metal halide lamp without an outer tube is generally used. . The single-tube type metal halide lamp has a gap along the external conductor inside the sealing part, and during the lighting by this gap, the connection part between the metal foil sealed on the sealing part of the arc tube and the external conductor is always outside air. Therefore, the connection portion between the metal foil and the external conductor is easily oxidized and melted. In order to suppress the occurrence of such oxidative fusing, the connection between the metal foil and the external conductor has to be kept at 350 ° C. or lower even during lighting. In order to keep the connection between the metal foil and the external conductor at 350 ° C. or lower, conventionally, a means of lengthening the metal foil to keep it away from the arc which is the heat source has been adopted, but inevitably the sealing part of the arc tube is It will be long. Further, in this case, it is necessary to lengthen the sealing portion as the lighting power of the metal halide lamp becomes higher, which is a problem when the projection type metal halide lamp device is made compact.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a metal halide lamp device which has a long life and is compact in size, which suppresses oxidative fusing of a connecting portion between a metal foil and an external conductor without lengthening the sealing portion of the arc tube. .

[0005]

DISCLOSURE OF THE INVENTION A metal halide lamp device according to the present invention is an arc tube having a reflecting mirror and an inner side of the reflecting mirror provided at right angles to the axis of the reflecting mirror and having electrodes at both ends. And a cooling means provided outside the reflecting mirror, wherein the sealing portion of the arc tube has a metal foil whose one end is connected to the electrode, and one end of which is the other end of the metal foil. And the other end of the arc tube is sealed to the external conducting wire led out of the sealing section, and the sealing section of the arc tube is provided outside the reflecting mirror.

[0006]

With this structure, the oxidative fusing of the connecting portion between the metal foil and the external conductor is suppressed without lengthening the sealing portion of the arc tube.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

In a projection type metal halide lamp device having a rated power of 150 W, which is an embodiment of the present invention shown in FIG. 1, a light emitting portion 1a and a sealing portion 3 connected to both ends of the light emitting portion 1a.
It has a quartz arc tube 1 composed of a and 3b, and a reflecting mirror 7 made of hard glass. A pair of electrodes 2a and 2b made of tungsten are provided inside the light emitting portion 1a, and the electrodes 2a and 2b are provided with an interelectrode distance of 4 mm in order to approach the point light source. Argon gas as a starting gas is enclosed in the light emitting portion 1a together with a predetermined amount of mercury, dysprosium iodide, neodymium iodide, and cesium iodide. The electrodes 2 are attached to the sealing portions 3a and 3b.
16mm length made of molybdenum connected to a and 2b
The metal foils 4a and 4b are sealed. Metal foil 4a, 4
Electrodes 2a and 2b are connected to one end of b, and one ends of external conductors 5a and 5b are connected to the other ends of the metal foils 4a and 4b to form a connection part 13. The other ends of the external conducting wires 5a and 5b are led out from the end faces of the sealing portions 3a and 3b. Lead wires 6a and 6b are connected to the other ends of the external conductors 5a and 5b, respectively. The arc tube 1 is
The metal foils 4a and 4b in the sealing portions 3a and 3b of the arc tube 1 and the external conductors 5a and 5 are perpendicular to the axis of the reflecting mirror 7.
The connecting portion 13 with b is arranged inside the reflecting mirror 7 so as to be located outside the reflecting mirror 7. That is, a part of the end of the sealed portion of the arc tube 1 is provided so as to project from the reflecting mirror 7. The reflecting mirror 7 is fixed to the arc tube 1 with cement 8. The reflecting mirror 7 has a parabolic or elliptical shape with an aperture diameter of 70 mm, and a multilayer interference film 9 that transmits infrared rays is deposited on the reflecting surface.

The reflecting mirror 7 is provided on the outer side of the reflecting mirror 7 on the side opposite to the reflecting surface.
Also, a fan 10 for cooling the connection portion 13 between the metal foils 4a and 4b and the external conductors 5a and 5b is installed. During lighting, air is blown from the rear of the lamp and the reflector 7 and metal foil 4
The connecting portion 13 between the a and 4b and the external conducting wires 5a and 5b is 350
Cool to below ℃.

In the projection type metal halide lamp device of this embodiment, since the sealing portions 3a and 3b of the arc tube 1 can be provided so as to project outside the reflecting mirror 7, the lamp device including the reflecting mirror 7 can be made compact. be able to. Further, since the sealing parts 3a and 3b of the arc tube 1, that is, the connecting parts 13 of the metal foils 4a and 4b and the external conducting wires 5a and 5b are provided outside the reflecting mirror 7, the sealing part of the arc tube 1 is formed. The connecting portion 13 can be cooled by blowing the fan 10 to 350 ° C. or lower without making the lengths 3a and 3b longer, and the oxidative fusing of the connecting portion 13 between the metal foils 4a and 4b and the external conductors 5a and 5b is prevented. Can be suppressed. Further, the temperature of the connecting portion 13 between the metal foils 4a and 4b and the external conductors 5a and 5b can be adjusted by arbitrarily adjusting the amount of air blown by the fan 10. Therefore, the metal foils 4a, 4b and the external conductors 5a, 5
It is possible to obtain a compact projection-type metal halide lamp device that has a long life and suppresses oxidative fusing of the connecting portion 13 with b.

Although the above embodiment has been described with reference to a projection type metal halide lamp of 150 W type, a high W type which emits more heat is used.
The same effect can be obtained with the type.

Next, a projection type metal halide lamp device having a rated power of 150 W which is another embodiment of the present invention will be described.

In the projection type metal halide lamp device of another embodiment of the present invention shown in FIG. 2, in addition to the configuration of the above-mentioned one embodiment, a front glass plate 11 made of hard glass having a thickness of 3 mm is reflected by the reflecting mirror 7. It is fixed to the surface side by the low melting point glass 12.

With this structure, in addition to the effect of the above-described one embodiment, the other embodiment of the present invention allows the cooling air from the fan 10 to be directly supplied to the arc tube 1 by the reflecting mirror 7 and the glass plate 11.
Therefore, it is possible to further suppress the variation in the electric characteristics and the light emitting characteristics during the lighting of the metal halide lamp due to the cooling air. Further, even if the arc tube 1 is damaged during the life of lighting, the fragments produced when the arc tube is damaged can be prevented from scattering by the front glass plate 11, and the liquid crystal projector main body (not shown) is damaged. It is possible to prevent the scattered glass fragments from scattering.

[0015]

As described above, according to the present invention, a reflecting mirror, an arc tube provided inside the reflecting mirror in a direction perpendicular to the axis of the reflecting mirror, and having electrodes at both ends thereof, And a cooling means provided on the outside of the reflecting mirror, wherein the sealing portion of the arc tube has a metal foil whose one end is connected to the electrode, and one end of which is on the other end of the metal foil. The external conductor is connected to the external conductor and the other end of the arc is led to the outside of the sealing portion, and the sealing portion of the arc tube is provided outside the reflecting mirror. It is possible to suppress oxidative fusing of the connection part between the metal foil and the external conductor, reduce the size of the reflecting mirror, shorten the sealing part of the arc tube, etc. A compact metal halide lamp device can be provided.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a projection type metal halide lamp device according to an embodiment of the present invention.

FIG. 2 is a partially cutaway front view of a projection type metal halide lamp device according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Arc tube 3a, 3b Sealing part 4a, 4b Metal foil 5a, 5b External conductor wire 7 Reflector 10 Fan 11 Glass plate 13 Connection part

Claims (3)

[Claims] 1. A reflector, an arc tube provided inside the reflector in a direction perpendicular to the axis of the reflector and having electrodes at both ends, and a cooling provided outside the reflector. And a metal foil having one end connected to the electrode, one end connected to the other end of the metal foil, and the other end connected to the seal. The metal halide lamp device is characterized in that it is sealed with an external conducting wire led out of the fitting part, and the sealing part of the arc tube is provided outside the reflecting mirror. 2. The metal halide lamp device according to claim 1, wherein a connecting portion between the metal foil and the external conducting wire is arranged outside the reflecting mirror. 3. The metal halide lamp device according to claim 1, wherein the reflecting mirror is provided with a front glass plate.