JPH05135747A - Metal halide lamp device - Google Patents

Abstract

PURPOSE:To prevent the open circuit of an auxiliary conductor line even if a light emitting tube is deformed during its life and stabilize startability in a metal halide lamp device having a reflecting mirror lighted horizontally. CONSTITUTION:Electrodes 2, 2' provided at both ends of a light emitting tube 1 sealed with an iodide are connected to molybdenum wires 4, 4' via molybdenum foils 3, 3'. A lead wire 7 and a base 8 are connected to the other ends of the wires 4, 4', a reflecting/heating insulating film 5 is applied on the outer surface of the electrode 2, an auxiliary conductor wire 6 connected to the molybdenum wire 4 at one end is arranged along the outer surface located below the center axis when the light emitting tube 1 is horizontally arranged, and the other end is connected to the surface of the light emitting tube 1 near the electrode 2'.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal halide lamp device, and more particularly to a metal halide lamp device which is equipped with a metal halide lamp and a reflecting mirror and is used as a light source for a relatively small image device for distributing light in an optically limited area. ..

[0002]

2. Description of the Related Art Conventionally, a small-sized metal halide lamp device which is formed by integrally or detachably combining a metal halide lamp and a reflecting mirror, which are composed only of an arc tube without using an outer tube, has a good color rendering property. Because of its high luminous efficiency, it is being used as a light source for overhead projectors, overhead type liquid crystal projectors, projection televisions using liquid crystals, and even projectors.

Generally, a metal halide lamp device used in such a device is often arranged horizontally for use, and such a metal halide lamp is downsized and has good color characteristics. Since a large amount of iodide is filled in compared with the inner volume of the arc tube, considerable energy is required at the time of starting. Therefore, the auxiliary conductor wire is usually arranged along the outer surface of the arc tube.

[0004]

Heretofore, this type of small metal halide lamp has been ideally designed to have a small light emitting portion and a shorter arc length because its main use is as a light source for video equipment. However, reducing the size of the light emitting part increases the load on the wall surface, and because a certain lamp voltage is obtained, the burden on the arc tube increases, such as a large amount of mercury being filled as a buffer, and the vapor pressure inside the arc tube increases accordingly. In addition, the surface temperature of the arc tube rises, and especially during horizontal lighting, the arc tube is deformed at an early stage.

This deformation of the arc tube is particularly remarkable in horizontal lighting, because the upper part of the arc tube becomes a high temperature point due to a phenomenon such as arc levitation. Therefore, an auxiliary conductor is attached to the deformation occurrence part on the upper side of the arc tube. In this case, the auxiliary conductor wire itself is deteriorated, and the auxiliary conductor wire is easily broken, which causes a problem that the startability is significantly deteriorated.

The present invention has been made to solve the above-mentioned problems in the conventional metal halide lamp device having a horizontally lit reflecting mirror. Even if the arc tube is deformed during its life, the auxiliary conductor wire is disconnected. It is an object of the present invention to provide a metal halide lamp device which does not generate a noise and has stable startability.

[0007]

In order to solve the above problems, the present invention is directed to a reflecting mirror having a parabolic surface or an elliptic surface, and an axis connecting both electrodes is the central axis of the reflecting mirror. In a metal halide lamp device comprising a metal halide lamp which is lit only by an arc tube without using an outer tube arranged in front of the reflecting mirror so as to be substantially aligned and positioned horizontally, the extraction of one electrode of the arc tube The auxiliary conductor wire connected to the wire is attached to the outer surface near the counter electrode along the outer surface of the arc tube below the central axis.

Since the auxiliary conductor wire is thus provided along the outer surface of the arc tube below the central axis of the arc tube, the temperature of the auxiliary conductor wire received by the arc tube is relatively low, so that the auxiliary conductor wire itself is deteriorated. In addition, since the external force due to the deformation of the arc tube is not applied, the risk of disconnection is reduced, and a metal halide lamp device with stable startability can be realized.

[0009]

EXAMPLES Next, examples will be described. FIG. 1 is a partially cutaway perspective view showing an embodiment of a metal halide lamp device according to the present invention. In the figure, 1 is a metal halide lamp arc tube made of quartz glass, which has an internal volume of 0.5 cc, a central maximum outer diameter of 11 mm, a maximum inner diameter of 9 mm, electrodes 2 and 2'on both ends, and mercury and argon. In addition, as the metal halide, 1 mg of dysprosium iodide, neodymium iodide, and cesium iodide each having a weight ratio of 4: 2: 3 is enclosed. The distance between both electrodes 2, 2'is set to 5 mm, and each electrode 2, 2'is connected to molybdenum wires 4, 4'via molybdenum foils 3, 3 '. A nickel lead wire 7 and a base 8 are connected to the other ends of the ′ ′ and the arc tube 1 respectively.
On the outer surface of one of the electrodes 2, a reflection and heat insulating film 5 made of Al ₂ O ₃ , SiO ₂ or the like for increasing the vapor pressure of the arc tube is provided. Further, when the arc tube 1 is horizontally arranged, the auxiliary conductor wire 6 having one end connected to the molybdenum wire 4 connected to the one electrode 2 is attached to the outer surface located below the central axis of the arc tube 1. , And the other end is bonded to the surface of the arc tube near the other electrode 2 '.

Then, a reflecting mirror 9 of f = 13 mm having a paraboloidal surface on which an infrared ray transmitting / reflecting film is formed is arranged so as to surround the arc tube 1 thus constructed, and the arc tube is mounted in its mounting hole. Insert the base 8 of No. 1 and fix it so that the axis connecting the two electrodes of the arc tube 1 substantially coincides with the central axis of the reflecting mirror 9, and pull out the nickel lead wire 7 to the outside of the reflecting mirror 9. , Connect to the connection terminal 10. Then, the arc tube is placed horizontally and the electric power of 150 W
It is designed to be lit by alternating current.

Next, a description will be given of an experiment conducted for confirming the operation and effect of the metal halide lamp device having the above structure. In this experiment, the one based on the above-mentioned example and the one arranged along the upper side of the central axis of the arc tube in which the auxiliary conductor wire was horizontally arranged for comparison,
Five pieces each were created and horizontally lit in a cycle of lighting for 2 hours and 45 minutes and extinguishing for 15 minutes. As a result, when the lighting time is about 500 hours, all arc tubes begin to deform, and by the time the lighting time reaches 1000 hours, all the auxiliary conductor wires arranged above the arc tube are auxiliary conductors. The wire was broken and the startability was significantly reduced. On the other hand, in the case where the auxiliary conductor wire according to the present invention is arranged on the lower side of the arc tube, the auxiliary conductor wire was not broken even after 1000 hours of lighting, and the startability was good.

[0012]

As described above on the basis of the embodiments,
According to the present invention, it is possible to realize a metal halide lamp device having stable startability without breaking the auxiliary conductor wire even if the arc tube is deformed during its life.

[Brief description of drawings]

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

[Explanation of symbols]

 1 arc tube 2, 2'electrode 3 molybdenum foil 4, 4'molybdenum wire 5 reflective and heat insulating film 6 auxiliary conductor wire 9 reflective mirror

Claims (1)

[Claims] 1. A reflecting mirror having a parabolic or elliptical surface and a front surface of the reflecting mirror are arranged such that an axis connecting the electrodes is substantially aligned with a central axis of the reflecting mirror and is positioned horizontally. In a metal halide lamp device comprising a metal halide lamp which is lit only by a light emitting tube without using an outer tube, an auxiliary conductor line connected to a lead wire of one electrode of the light emitting tube is provided below the central axis of the light emitting tube. A metal halide lamp device characterized in that it is attached to the outer surface near the counter electrode along with the outer surface of the metal.