JPH0652836A - Metal halide lamp device - Google Patents

Abstract

PURPOSE:To provide a long-life metal halide lamp by uniforming the whole temperature of a luminous tube as much as possible. CONSTITUTION:For an approximately horizontal lighting type metal halide lamp device, a blowing pipe 7 of light transmissive material is provided at a base 5. The blowing pipe 7 has the end directed to the upper part of the outside surface of a luminous tube 1. A distance L between the end of the blowing pipe and the top of the outside surface of the luminous tube 1 is set to be 1mm<=L<=10mm in fixing to greatly decrease the temperature of the upper tube wall without decreasing the coldest temperature point of the luminous tube.

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, and more particularly to a metal halide lamp device having a reflecting mirror and used as a relatively small light source for video images.

[0002]

2. Description of the Related Art Conventionally, halogen lamps have been widely used in projectors, overhead projectors, etc. due to their characteristics as a highly efficient and compact light source, but in recent years, they have been more efficient and have a high color rendering property. A compact metal halide lamp was developed, and in addition to the above equipment,
It is also used in overhead type projection televisions that use liquid crystals.

[0003]

In such a relatively small-sized metal halide lamp, the light emitting source is made small and the load on the high tube wall is set to increase the vapor pressure of the metal halide having a low vapor pressure. The glass arc tube is liable to be devitrified by heat or swelled and deformed. The devitrification and the deformation are accelerated as the temperature of the arc tube becomes more nonuniform, that is, as a high temperature portion locally exists.

However, generally, in a metal halide lamp, the lower part of the arc tube of the lamp is the coldest point, and the upper part of the arc tube is the highest temperature due to convection. Furthermore, in a metal halide lamp that is lit substantially horizontally, in a stable arc state, the arc curves above the tube axis, so the heat of the arc is transferred to the upper tube wall and the temperature difference with the lower tube wall increases, resulting in It led to a short life of the metal halide lamp. The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide a metal halide lamp having a long life by making the temperature of the entire arc tube as uniform as possible.

[0005]

In order to achieve the above object, the present invention provides a metal halide in which an arc tube in which at least a metal halide lamp is enclosed without an outer tube is arranged with its arc axis substantially horizontal and combined with a reflecting mirror. In the lamp device, a base provided with at least one blower pipe made of a translucent material is provided at one end of the arc tube, and the base is fixed to a mounting hole of the reflecting mirror to mount the arc tube on the reflecting mirror. Aim the tip of the blower pipe to the upper part of the outer surface of the arc tube,
In addition, when the distance between the tip of the air blow pipe and the apex of the outer surface of the arc tube is L, the air blow pipe is fixed so that 1 mm ≦ L ≦ 10 mm, and the air is cooled by air blow.

The invention according to claim 2 is characterized in that a translucent partition plate is provided in the reflecting mirror in order to prevent air flowing along the upper tube wall of the arc tube from flowing into the lower tube wall. To do.

[0007]

With the above construction, when the tip of the air blowing pipe is directed to the upper part of the outer surface of the arc tube and the distance between the tip of the air blowing pipe and the apex of the outer surface of the arc tube is L, 1 mm≤L≤1
Since the blower pipe is fixed to 0 mm and the blower is cooled, the temperature gradient of the arc tube is reduced, so that devitrification and deformation of the arc tube are suppressed, and the life of the arc tube can be kept long.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the metal halide lamp device of the present invention will be described with reference to the drawings. FIG. 1 shows a cross section of a metal halide lamp device of the present invention which is lit substantially horizontally,
The arc tube 1 is a 250 W rated lamp power arc tube made of quartz glass having an internal volume of 1.0 cc, an arc length of 7 mm, and a maximum diameter of a light emitting portion of 13 mm. Electrodes 2 are provided at both ends of the arc tube 1.
2 ', and in addition to mercury and argon, dysprosium iodide, neodymium iodide, cesium iodide, and lithium iodide are used as rare earth metal halogen compounds in a ratio of 4: 4: 6: 1.
It has been selected to contain 1.5 mg. The electrodes 2, 2'are connected to molybdenum foils 3, 3 ', and the molybdenum foils 3, 3'are
Are further connected to molybdenum ears 4, 4 '.
The wire 4 is connected to a base 5 provided at one end of the arc tube 1, and a nickel lead wire 6 is connected to one wire 4 '.

A circular hole is formed in the base 5, and a blower pipe 7 made of quartz glass which is a translucent heat-resistant material is passed through the base along the thin side of the sealed portion of the arc tube 1. Has been done. The tip of the blower pipe 7 is directed to the upper part where the surface temperature of the arc tube is highest.

In this embodiment, the distance between the tip of the blower pipe 7 and the apex of the outer surface of the arc tube is 5 mm. Also, arc tube 1
A heat insulating film 8 made of white heat-resistant oxide is provided on the tube wall near the electrode 2 '. The arc tube 1 configured as described above is provided with a reflecting mirror 9 having a parabolic surface coated with an infrared transmitted light reflection film so that the arc tube 1 is substantially in focus.
The reflecting mirror 9 is set to distribute light to a specific area. The arc tube 1 and the reflecting mirror 9 are attached by fitting the arc tube 1 into the mounting hole provided in the reflecting mirror 9.
The base 5 is fixed with an inorganic adhesive.

The effects of the metal halide lamp device configured as described above will be described. First, the metal halide lamp device (hereinafter, lamp N
o. 1)) and the metal halide lamp device having the above-described configuration (hereinafter, referred to as Lamp No. 2) in which air is blown with the distance between the tip of the blower pipe and the apex of the outer surface of the arc tube being 13 mm.
And a metal halide lamp device (hereinafter, referred to as lamp No. 3) having the above-mentioned configuration, which was blown in this example, was prepared and evaluated. The evaluation method is as follows. Each metal halide lamp device (No. 1, 2, 3) is installed in a device such as an overhead projector and the lamp power is 25
It was lit horizontally at 0 W, and the outer surface temperature of the quartz arc tube, the total luminous flux color rendering index Ra, and the color temperature of the portions indicated by points A, B, and C in FIG. 1 were measured. The results are shown in Table 1.

[0012]

[Table 1]

As shown in Table 1, No. The metal halide lamp device of No. 1 has extremely excellent optical characteristics, but because the temperature gradient of the arc tube is large, a life test of 2000 hours was performed to measure the illuminance maintenance rate, and the illuminance maintenance rate was about 42%. It was low and the deformation of the upper part of the arc tube was remarkable. In addition, No. 20 for 2 metal halide lamp devices
In the 00-hour life test, the illuminance maintenance rate was about 57%,
The upper part of the arc tube is also deformed by changing the lamp It was less than 1. On the other hand, No. The metal halide lamp device of No. 3 has the best characteristics among the three lamps,
In a life test of 00 hours, a high illuminance maintenance ratio of about 69% was exhibited, no deformation of the upper part of the arc tube was observed, and the optical characteristics were No. It was found that there was almost no change as compared with the No. 1 metal halide lamp device, and the decrease in the initial illuminance was as small as 2 to 5%.

Further, as a result of variously changing the distance L between the tip of the blower pipe and the apex of the outer surface of the arc tube, the distance L becomes L.
In the case of> 10 mm, as the distance L increases, the air flow is scattered and the lower temperature of the arc tube is considerably lowered. Further, when L <1 mm, only the part where the tip of the blower pipe faces is cooled, and the entire upper part of the arc tube cannot be cooled. Therefore, the distance L between the tip of the blower pipe and the outer surface of the arc tube is 1 mm ≦ L ≦ 10 mm.

The amount of air blown through the arc tube depends on factors such as the shape of the arc tube, but is 1500 ml / min.
If the amount is higher, the upper temperature will be lower than the lower temperature and iodide will adhere to the upper part, resulting in low initial illuminance and 300 ml / m
When it is less than in, the lowering of the upper temperature of the arc tube is small.
Therefore, the air flow rate is 300 ml / min to 1500
ml / min is appropriate.

The light-transmitting material is used as the material for the blast pipe in order to prevent a decrease in the initial illuminance. Therefore, it is not preferable to use an opaque material such as ceramic or metal for the blower pipe material because the initial illuminance decreases by 8 to 15%. In this way, a base provided with at least one blower pipe made of a translucent material is provided at one end of the arc tube, and the tip of the blower pipe is directed to the upper part of the outer surface of the arc tube. It has been confirmed and proved that by setting the distance L to the outer surface to be 1 mm ≦ L ≦ 10 mm, the most effective blow cooling can be performed and a long-life metal halide lamp device excellent in optical characteristics can be obtained.

A second embodiment of the present invention will be described below with reference to FIGS. 2 and 3 are cross-sectional views of a second embodiment of a horizontally lit metal halide lamp device according to the present invention. The difference from FIG. 1 is that the air flowing above the outer surface of the arc tube 1 is below the outer surface. The point is that a partition plate 10 made of quartz glass, which is a translucent and heat-resistant material, is provided in the reflecting mirror so that it does not easily flow. The other parts are the same as those in FIG. 1 and their explanations are omitted.

The effect of the metal halide lamp device of the second embodiment will be described. The blown air-operated metal halide lamp device of the second embodiment (hereinafter referred to as lamp No. 4) was prepared and evaluated. This lamp No. Four
Lamp No. described above. As with 12 and 3, built-in devices such as overhead projectors, power 250W
Then, the temperature of the outer surface of the quartz arc tube, the total bundle color rendering index Ra, and the color temperature of the portions indicated by points A, B, and C in FIG. 1 were measured. The measurement results are shown in Table 2.

[0019]

[Table 2]

As shown in Table 2, No. The metal halide lamp device of No. 4 has extremely excellent optical characteristics,
As a result of performing the 0-hour life test and measuring the illuminance maintenance rate,
The illuminance maintenance rate was about 75%, and no deformation of the upper part of the arc tube was observed. In this way, the tip of the air-blowing pipe made of a translucent material is directed toward the upper part of the arc tube, the distance L between the apex of the outer surface of the arc tube and the tip of the air-blowing pipe is set to 1 mm ≤ L ≤ 10 mm, and the translucency in the reflecting mirror By providing the partition plate of
It was confirmed that a long-life metal halide lamp device having excellent optical characteristics can be obtained.

[0021]

As described above, the present invention is a metal halide lamp device in which an arc tube in which at least a metal halide lamp is enclosed without an outer tube is arranged with its arc axis substantially horizontal and is combined with a reflecting mirror. A base provided with at least one blower pipe made of is provided at one end of the arc tube, and the base is fixed to a mounting hole of the reflecting mirror to attach the arc tube to the reflecting mirror, and the tip of the blower pipe is outside the arc tube. The blower pipe is fixed so that 1 mm ≦ L ≦ 10 mm, and the blower is cooled so that 1 mm ≦ L ≦ 10 mm, where L is the distance between the tip of the blower pipe and the apex of the outer surface of the arc tube. Since it is a metal halide lamp device, it is possible to significantly lower the temperature of the upper tube wall without lowering the coldest spot temperature of the arc tube and prevent the lamp from being deformed when it is lit for a long period of time. At the same time, it is possible to provide a long-lived metal halide lamp device having excellent optical characteristics.

According to the invention of claim 2, in addition to the above structure, a translucent partition plate is provided in the reflecting mirror in order to prevent air flowing along the upper tube wall of the arc tube from flowing into the lower tube wall. Since it is a metal halide lamp device characterized by being equipped with a partition plate, it is possible to significantly lower the temperature of the upper tube wall with almost no lowering of the coldest spot temperature of the arc tube. It is possible to provide a long-life metal halide lamp device which is prevented from being deformed and which has a high illuminance maintenance rate and excellent optical characteristics.

[Brief description of drawings]

FIG. 1 is a sectional view of a horizontally lit metal halide lamp device according to a first embodiment of the present invention,

FIG. 2 is a sectional view of a horizontally lit metal halide lamp device according to a second embodiment of the present invention,

FIG. 3 is a cross-sectional view of a horizontally lit metal halide lamp device according to a second embodiment of the present invention when viewed from a direction perpendicular to FIG.

[Explanation of symbols]

 1 arc tube 2,2 'electrode 3,3' molybdenum foil 4,4 'molybdenum wire 5 base 6 nickel lead wire 7 blower pipe 8 heat insulating film 9 reflector 10 partition plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuko Ito 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Hideaki Omura 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A metal halide lamp device in which an arc tube in which at least a metal halide lamp is enclosed without an outer tube is arranged with its arc axis substantially horizontal and combined with a reflecting mirror, at least one blower pipe made of a translucent material is used. The base provided here is provided at one end of the arc tube, the base is fixed to the mounting hole of the reflecting mirror to attach the arc tube to the reflecting mirror, and the tip of the blower pipe is directed to the upper part of the outer surface of the arc tube.
Further, the metal halide lamp device is characterized in that, when the distance between the tip of the blower pipe and the apex of the outer surface of the arc tube is L, the blower pipe is fixed so that 1 mm ≦ L ≦ 10 mm and the blower is cooled. 2. The translucent partition plate is provided inside the reflecting mirror to prevent air flowing along the upper tube wall of the arc tube from flowing into the lower tube wall. Metal halide lamp device.