JPS63281345A - Infrared ray lamp - Google Patents

Abstract

PURPOSE:To obtain an infrared ray lamp which suppresses the luminance in a visible region and in a far infrared region to the utmost extent, while a strong emission spectrum in the fixed near infrared region and excellency in its durabil ity by sealing mercury, rare gas and bismuth halide together with a pair of electrodes for discharge in a luminous tube. CONSTITUTION:The infrared ray lamp in the caption for radiating the infrared rays having more than a fixed wave length region necessary for a dark visible field or the like has a luminous tube 1 for transmitting infrared rays and seals a pair of electrodes 2 and 3 together with sealing mercury, rare gas and the halide of bismouth in the luminous tube 1. That is, the discharge starting by rare gas and the shifting to mercury discharge are promoted by impressing voltage on the electrodes 2 and 3 and discharge heat in the meantime promotes evaporation of the bismoth halide and the excitation, in an arc, of the rubidium atoms separated from halogen atoms to act for radiating the rays of a strong emission spectrum in the near infrared region. This action enables the rays having the strong emission spectrum in the near infrared region to be generated and besides to be used as a source of light and to lengthen a life.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an infrared light lamp that has a strong emission spectrum in the near-infrared region and is used as a light source for night vision devices.

[Conventional technology]

FIG. 5 is a partially cutaway front view of a conventional infrared lamp disclosed in, for example, Japanese Patent Publication No. 44-30313. 7 is a reflective plate treated with a reflective surface along with the inner surface of the projector body 6, 8 is an infrared transmitting/visible reflective filter, 9 is an infrared transmitting/visible absorbing filter, and 10 is a protective glass plate.

Next, the operation will be explained.

When a current is applied to the halogen lamp 5, the halogen lamp 5 generates radiation having a spectral distribution as shown in FIG. Set in.

The emitted light reaches an infrared transmission/visible reflection filter 8, where only the infrared light in the emitted light is transmitted. The infrared transmission/visible absorption filter 9 absorbs the visible light that has passed through the infrared transmission/visible reflection filter 8 and transmits only the infrared light. 8 in the infrared range
00 nm light is projected outside, for example, into a dark field region.

[Problem that the invention seeks to solve]

Since the conventional infrared light lamp is configured as described above, in order to obtain near-infrared light having a wavelength of gQQnm or more, the reflector 7. Infrared transmitting/visible reflective filter 8 and infrared transmitting/visible absorbing filter 9 must be used, which makes the configuration complicated, and visible light of the light emitted from halogen lamp 5 is transmitted through each filter in projector body 6. The far infrared light is converted into thermal energy in the filters 8 and 9.
It comes into contact with the reflector plate 7 and is converted into thermal energy.

As a result, the temperature of the projector main body 6 increases, resulting in a significant shortening of the life of the halogen lamp 5 to 2,000 to 3,000 hours.As each filter 8.9 is required to be heat resistant, the overall However, there were problems such as an unavoidable increase in costs.

This invention was made to solve the above-mentioned problems, and by using bismuth halides, it suppresses emission in the visible and far-infrared regions as much as possible, and has a strong emission spectrum in the predetermined near-infrared region. Moreover, the object is to obtain an infrared lamp with excellent durability.

[Means for solving problems]

The infrared light lamp according to the present invention has an arc tube that transmits light, and a pair of electrodes for discharge is sealed in the arc tube,
Furthermore, it is constructed by enclosing mercury, a rare gas, and a cesium halide.

[For production]

By applying a voltage to the electrode in this invention, the initiation of discharge by rare gas and the transition to mercury discharge are promoted, and during this time, the discharge heat causes bismuth halide to evaporate and rubidium atoms separated from halogen atoms to evaporate in the arc. It acts to promote excitation and emit light with a strong emission spectrum in the near-infrared region.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 1 is an arc tube made of quartz glass, and electrodes 2 and 3 for discharge are provided at both ends of the arc tube 1.
In addition to appropriate amounts of mercury and rare gas (not shown), bismuth iodide 4, which is one of the bismuth halides, is sealed inside.

Next, the operation will be explained.

The infrared light lamp constructed as shown in FIG. 1 has an ordinary outer bulb made of hard glass as the arc tube 1.
Use a metal halide lamp similar to that used for general lighting.

Appropriate amounts of mercury, rare gas, and bismuth iodide 4 sealed in the arc tube 1 are supplied from the outside via a ballast (not shown). When a voltage is applied between the electrodes 2 and 3, the rare gas first discharges the begins, and then gradually transitions to mercury discharge. Due to the heat of the discharge generated at this time, the bismuth iodide 4 sealed in the arc tube 1 gradually evaporates. This bismuth iodide 4 decomposes into bismuth and iodine in the arc, and the bismuth atoms are excited in the arc, resulting in the characteristic 934 nm, 966 nm, 9 as shown in Figure 4.
It emits a spectrum of 83 nm in the near-infrared region.

Next, when emitting light in the infrared region as described above,
For example, it is desirable to set the emission intensity of the infrared light with a wavelength of 966 nm to be optimal depending on the amount of bismuth iodide 4 sealed in the arc tube 1 and the magnitude of the load on the tube wall. In the present invention, the optimal amount of filling and the magnitude of the tube wall load under certain conditions are determined based on the following experimental data.

Therefore, the arc tube 10 input was set to 400 W, the tube wall load (W/m2), the tube inner diameter (mm), the distance between electrodes 2 and 3 (
mm) and internal volume (cc), respectively, as shown in specifications A to E in the table below.

In addition to an appropriate amount of mercury and rare gas, the arc tube 1 with the above specifications contains
The amount of bismuth iodide 4 as a bismuth halide was 0.6 cc/cc with respect to the internal volume of the arc tube 1.

1.3mg/cc, 2.6■/cc, 3.9m
g/cc, 5.41c, and three arc tubes were fabricated as prototypes.

Therefore, the tube wall load of arc tube 1 and the enclosed bismuth iodide 4
As a result of actually measuring the relationship between the amount of bismuth iodide and the emission intensity at 966 nm, as shown in FIG.
Compared to the enclosed amount of 6 .mu./CC or more, the luminescence intensity was very low no matter how much the tube wall load increased. The reason for this is thought to be that the luminous intensity was not significantly increased due to insufficient amount of bismuth evaporated into the arc tube 1.

Also, the amount of bismuth iodide is from 1.3mg/cC to 3.9mg
/ CC, the emission intensity also increases, and as the tube wall load of the arc tube 1 increases, the emission intensity further increases. When the tube wall load exceeded 23 W/crIL to 25 W/cm, an unstable arc state occurred in the arc tubes 1 of all specifications. The reason for this is thought to be that the evaporation rate of bismuth in the arc tube 1 becomes faster and moves the arc.

On the other hand, as a result of actually measuring the relationship between the amount of bismuth iodide enclosed and the emission intensity at 966 nm, as shown in Figure 3,
To obtain a practical luminous intensity, the amount of bismuth iodide should be 1.3 mg/cc to 3.9 mg/cc relative to the internal volume of the arc tube 1.
cc was found to be optimal.

Sunawachi, 0 with bismuth iodide less than 1゜3mg/CC
．． 6■/cC is not practical because the emission intensity at 966nm is weak, and 5.2■/C exceeds 3.9mg/cc.
It was confirmed that when the temperature reached C, liquid bismuth iodide accumulated in the coldest part of the arc tube 1, and rapid evaporation occurred from the liquid part, making the arc unstable.

From the above results, the amount of bismuth iodide sealed in the arc tube 1 is 1.3 in the area indicated by arrow Q relative to the internal volume of the arc tube 1.
mg/cc to 3.9 mg/CC, and the tube wall load of arc tube 1 is 15 W/cm in the area indicated by arrow P to 23 W.
/cm 2 , an efficient infrared lamp for near-infrared radiation can be obtained.

In addition, as a result of subjecting the prototype arc tube 1 to a life test, 6
After 500 hours, the desired luminescence intensity of 78 cm was obtained, and a satisfactory result was obtained.

In the above embodiments, bismuth iodide was used, but fluorides, chlorides, and bromides other than iodide may also be used, and the same effects as in the above embodiments can be obtained.

Further, although the arc tube 1 made of quartz glass is used in the above embodiment, a heat-resistant and translucent material such as translucent ceramic may be used, and the same effects as in the above embodiment can be obtained.

[Effects of the Invention] As described above, according to the present invention, mercury, rare gas, and bismuth halide are sealed together with a pair of discharge electrodes in an arc tube that transmits infrared light. , it is possible to generate light with an emission spectrum in a predetermined near-infrared region, and by selecting the optimum amount of the bismuth halide and the size of the tube wall load, it is possible to generate light with a strong emission spectrum in the near-infrared region. In addition to making it possible to generate light, it also has the effect of providing a light source that can be used as a light source for night vision devices and has a longer lifespan.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an infrared light lamp according to an embodiment of the present invention, FIG. 2 is a graph diagram showing the relationship between the magnitude of the tube wall load of the arc tube and the emission intensity at a wavelength of 966 nm, and FIG.
The figure is a graph showing the relationship between the amount of bismuth iodide filled and the emission intensity at a wavelength of 966 nm. Figure 4 is a spectral distribution diagram of an arc tube filled with bismuth iodide. Figure 5 is a conventional infrared lamp. FIG. 6 is a partially cutaway front view showing the spectral distribution of light from the halogen lamp. 1 is an arc tube, 2 and 3 are electrodes, and 4 is bismuth halide.

Claims (2)

[Claims] (1) An infrared lamp that emits infrared light in a predetermined wavelength range or more necessary for night vision, etc., has an arc tube that transmits the infrared light, and a pair of electrodes is sealed within the arc tube. An infrared light lamp characterized by containing mercury, a rare gas, and bismuth halide. (2) Increase the tube wall load of the arc tube from 15W/cm^2 to 23W
/cm^2, and the amount of bismuth halide sealed in the arc tube is 1.3 mg/cm^2 with respect to the inner volume of the arc tube.
The infrared light lamp according to claim 1, characterized in that the infrared light lamp has a concentration of cc to 3.9 mg/cc.