JPS60235353A - Electrodeless discharge lamp - Google Patents

Abstract

PURPOSE:To obtain white light with high color rendering and high luminous efficacy by specifying the charged volume of mercury, thallium, sodium, indium, rare gas and halogen in the inside of a luminescent tube and specifying the load of a tube wall and the air speed of cooling air for a lamp. CONSTITUTION:A luminescent tube 2 is formed by transparent quartz glass and is charged with mercury of 1.4X10<-5> gram atom - 4.24X10<-5> gram atom thallium of 1X10<-7> gram atom - 4X10<-7> gram atom, sodium of 2.3X10<-7> gram atom - 1.4X10<-6> gram atom, indium of 1.1X10<-7> gram atom - 1.85X10<-6> gram atom, halogen of 9.3X10<-7> gram atom - 8.45X10<-6> gram atom and rare gas for starting of 20Torr-150Torr per content 1cm<3> of the luminescent tube in the inside. And while mictowave inputs per surface area 1cm<2> of the inner wall of the luminescent tube are set to the range of 6W-60W, the lamp is forcedly to cooled by cooling air.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an electrodeless discharge lamp used in a light source device etc. by utilizing discharge caused by microwave energy, and in particular to obtaining white light as a light source for illumination. This invention relates to an electrodeless discharge lamp that can be used.

[Prior art]

Recently, a microwave light source device equipped with an electrodeless discharge lamp that discharges and emits light using microwaves has been proposed.
In particular, research is being carried out on light source devices equipped with electrodeless discharge lamps for use as white light sources with high color rendering properties for illumination purposes.

For example, JP-A-55-39190 proposes an electrodeless discharge lamp in which a rare earth metal halide is sealed in addition to mercury and a rare gas. That is,
In this publication, argon Ar, mercury Hg, dysprosium iodide DYI3, holsium halide Hol3, mercury bromide HgBr2, cesium iodide CsI are enclosed, or Ar-Hg-NdI3-DyI3-Cs I is enclosed. , or Ar-Hg-Pr-DyI3-HgI
Encapsulating 2-CsI-HgBr2 or Ar-Ar
-Hg-Yb-CsC1-1H electrodeless discharge lamps are respectively shown. According to this electrodeless discharge lamp, it has the characteristics of a white light source, and when lit at high frequency, the radiation of the molecular emission continuum is greater than that of the conventional right-hand polar lamp, as shown in the spectral power distribution. Therefore, good color rendering properties are obtained. Also, Hg
-5cc13-Cs I-Ar Continuum radiation has also been observed in an electrodeless discharge lamp containing -5cc13-Cs I-A r. However, in this proposed electrodeless discharge lamp, the supply amount of the microwave electric lamp, its luminous efficiency, color rendering index, etc. are unknown, and there are problems in terms of practical use.

[Summary of the invention]

The present invention relates to an electrodeless discharge lamp containing and adding metal halide that is operated in a microwave electromagnetic field, and the present invention relates to the size of the lamp, the type and amount of metal halide added, the power supplied to the lamp, and the characteristics for cooling the lamp. The purpose of this study is to provide an electrodeless discharge lamp that emits white light for illumination.

That is, the present invention forms an arc tube in an electrodeless discharge lamp that discharges and emits light by microwaves from transparent quartz glass, and contains 1.4X10-g atoms to 4.24XlO-5 grams per volume tcm3 inside the arc tube. Atomic mercury and t x t o-'' gram atom to 4
, 4 X t o (gram atom of sodium and 1
．． Filled with indium from 1X10'' to 1.85X10' gram atoms, halogen from 9,3X IO''-'' to 8,45X 10' gram atoms, and rare gas for starting from 20 torr to 150 torr. The invention is characterized in that the heat source is forcibly cooled by cooling air.

When the inventors sealed a metal halide used in a conventional electrode-type metal halide lamp into an arc tube, they found that the spectral radiation intensity corresponding to the enclosed metal was different from the spectral distribution of an electrode-type metal halide lamp. I found out that Therefore, we investigated the type and amount of metal halide, the amount of power supplied to the lamp, the size of the lamp arc tube, etc. as described below, and determined that an electrodeless discharge lamp is better than an electrode-type metal halide lamp. Characteristics were obtained.

[Embodiments of the invention]

Next, specific embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 shows an electrodeless discharge lamp 1 made of spherical transparent quartz glass with an inner diameter of 30 mm.
It includes an arc tube 2 with a wall thickness of 1.0 mm, and a support rod 3 extending and protruding from the bottom of the arc tube 2. Inside the arc tube 2, predetermined amounts of mercury, thallium, sodium, indium, and halogen, which will be described later, are sealed. In addition, when encapsulating thallium and sodium, thallium halide and sodium halide, for example,
Indium is encapsulated in the form of thallium iodide and sodium iodide NaI, and in the form of a sufficient amount of mercury halide which reacts with metallic indium.

FIG. 2 shows a microwave light source device incorporating the electrodeless discharge lamp 1 described above. That is, this microwave light source device includes a magnetron 5 disposed below a casing 4. A waveguide 6 is connected to the magnetron 5 for radiating generated microwaves via a magnetron antenna 5a. A power feed port 8 provided in a power feed port flange 7 is provided at the upper end opening of the waveguide 6.
are aligned, and a microwave cavity 9 is formed above the power feeding port 8. An electrodeless discharge lamp l is disposed within this microwave cavity 9, and the lower end of the support rod 3 is inserted into a receiving portion 7a integrally formed with the power supply port flange 7, and a nut member is inserted into the receiving portion 7a. 10 and supported by the receiving portion 7a. Therefore, when the microwave generated by the magnetron 5 is radiated into the waveguide 6 by the magnetron antenna 5a, this microwave propagates inside the waveguide 6 and is further radiated from the feed port 8 to the microwave cavity 9. Therefore, it is mainly supplied to the electrodeless discharge lamp l.

Therefore, the electrodeless discharge lamp 1 discharges and emits light. By the way, the microwave cavity 9 is made of a mesh made of stainless steel, and allows 90% of light to pass therethrough, but reflects the microwave and hardly allows it to pass therethrough. A concave luminous intensity plate 11 is arranged around the microwave cavity 9, and the light emitted from the electrodeless discharge lamp 1 is effectively utilized by this light reflecting plate 11.

A fan 12 for cooling the magnetron 5 is arranged below the magnetron 5, and a fan 13 for cooling the electrodeless discharge lamp 1 is arranged on the wall side of the waveguide 6. The cooling air from this cooling fan 13 is guided into the waveguide 6 through a plurality of holes 6a provided in the waveguide 6, and is blown from the power supply port 8 onto the electrodeless lamp 1. l is cooled.

In the microwave light source device having such a configuration, the electrodeless discharge lamp 1 is turned on as described above, and the microwave power supplied to the electrodeless discharge lamp 1 and the cooling fan 13 are
By changing the lamp cooling air volume from
When the sentence m/W) was investigated, the results shown in FIG. 3 were obtained.

By the way, inside the arc tube 2 of the electrodeless discharge lamp 1,
Mercury at gram atom/crn', thallium iodide at gram molecule/cm', sodium iodide at gram molecule/crn', indium metal at gram atom/cm', and argon gas as a rare starting gas at room temperature. It is sealed under a pressure of 60 torr.The velocity of the cooling air from the fan 13 on the circumferential surface of the arc tube 2 is the microwave power W e (W/c) per 1 cm' of the inner wall area of the arc tube 2.
rn'), that is, tube wall load and luminous efficiency η(l m /
W) was investigated as a parameter.

- Now, in the diagram, in curve (a), the cooling air speed is 0.
The relationship between the tube wall load We and the luminous efficiency η in the case of / S e C is shown, and the curves (B), (C), (D), (E)
The cooling air speed is 1m/sec, 5m/see
, ion/sec and 20 m/sec, the relationship between the tube wall load We and the luminous efficiency η is shown. As is clear from the curve (A), when the tube wall load We, that is, the microwave input to the lamp 1 is increased from 6 W/crn', the lamp luminous efficiency η gradually increases, and after reaching the maximum value, At this point, the pipe wall load We gradually decreases to 20 W.
When it reaches the level of /c, the discharge becomes unstable. When the tube wall load We is less than 6 W/crn', the tube wall load of the lamp is too low and mercury aggregates, making it impossible to obtain a normal discharge, and at the same time, the emission of sodium decreases, making it impossible to obtain white light. . Also, in curves (b), (c), (d), and (e), when the tube wall load We increases, the lamp luminous efficiency η traces a curve similar to the curve (a), but the maximum luminous efficiency η
was approximately 95 sentences m/W. In particular, the curves (D) and (E) are close to each other, which indicates that even if the speed of the lamp cooling air is increased, the lamp cooling effect is saturated. Therefore, it can be seen that even if the wind speed is increased to 20 m/sec or more, the cooling effect hardly changes.

Next, we examined the substances to be filled into the arc tube 2 of the electrodeless discharge lamp 1, such as halides, and found that the amount of mercury is 1.4 x 10 gram atoms per volume of the arc tube 2. /crn”～4
, 24
．． If it is less than 4X10', the lamp will be destroyed;
If it exceeds IO-5, the discharge becomes unstable and is not practical. The amount of thallium enclosed is lXl0- gram atom/crn" to 4 X 10-7 gram atom/c
If m' is appropriate, if it is less than 1 x 10-7, the green emission line in the atomic spectrum of thallium will be weak and the light color will not be white but purple, and if it exceeds 4 x 10-'', it will become a color close to yellow. The amount of sodium enclosed is between 2.3X 10-"gram atom/crn" and 1.4X10' gram atom/cm.
” is appropriate, and if it is less than 2.3
The bright line spectrum at 8 nm is not broadened, the color rendering properties are deteriorated, and if it exceeds 1.4 x 10', the discharge becomes unstable, making it impractical. Regarding the amount of indium enclosed, 1.
lX10-7 gram atoms/cm' to 1,85
10-' gram atom/Cm" is suitable and 1.1X1
If it is less than 0-, indium emits less light and the light color becomes yellowish, making it impossible to obtain white light.
If it exceeds -', the discharge becomes unstable and it becomes impractical.

In addition, for the Ar gas that is the starting gas, it is appropriate to have 20 torr to 150 torr at room temperature, and 20 torr.
If it is less than orr, the lamp will be destroyed immediately after lighting, and 150 to
If it exceeds rr, the lamp will not light up.

Furthermore, regarding the type and amount of halogen gas to be filled, iodine, bromine, and chlorine, which are halogen elements other than fluorine, are suitable, and a mixture of these may be used. In particular, good optical properties were obtained when iodine and bromine were mixed. The amount of halogen gas enclosed is sufficient to form a halide with the enclosed metals excluding mercury and argon, and excess halogen is o, txto'' gram atom/Cm.
' to 3 x 10-gram atoms/crn' amount to be enclosed,
That is, 9.3X1O'' to 7,81X10-'
Gram atoms/crn' is suitable. Here, the reason for filling excess halogen is to reduce the devitrification phenomenon of quartz in the metal, etc., which can extend the life of the lamp. If it is less than 0, the effect will be small;
If it exceeds 6XIO', starting becomes difficult.

FIG. 4 shows the emission spectrum distribution of the electrodeless discharge lamp 1 of the present invention shown in FIGS. 2 and 3, in which the arc tube 2 has an inner diameter of about 30 mm and a wall thickness of about 1.

Om m, cooling air speed is approximately 1Om/SeC, lamp 1
These are the results of lighting under conditions where the microwave power to the tube was 850 W, that is, the tube wall load We was approximately 30 W/ctn''.

At this time, the color temperature was 4300, the average color rendering index Ra was 70, the total luminous flux was 80100 um, and the luminous efficiency η=94.2 (Jim/W) was obtained.

〔Effect of the invention〕

As explained above, according to the present invention, the amount of mercury, thallium, sodium, indium, rare gas, and halogen filled in the arc tube is specified as described above, and the tube wall load and the wind speed of the lamp cooling air are also specified as described above. By specifying as such, it is possible to provide an electrodeless discharge lamp that can obtain white light with high color rendering and high luminous efficiency.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the electrodeless discharge lamp of the present invention, Fig. 2 is a sectional view showing the electrodeless discharge lamp of the present invention;
The figure is a cross-sectional view of a microwave discharge light source device incorporating the electrodeless discharge lamp shown in Figure 1, and Figure 3 shows the luminous efficiency η (cross m
/W), and FIG. 4 is a diagram showing the emission spectrum distribution of the electrodeless discharge lamp of the present invention. 1----1-electrodeless discharge lamp, 2--1--discharge tube,
3-----One support rod, 4-----Casing, 5-
---- Magnetron, 5a ------- Magnetron antenna, 6------ Waveguide, 7--- Feeding loft flange, 8--- One feeding port, 9--- One Microwave cavity, to---nut member, 11---111 light reflector, 12.13---fan. In the drawings, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa Figure 1 Figure 3 Tube “1%, fiWe (W/crtr) 2nd Figure Research Institute

Claims (1)

[Scope of Claims] An electrodeless discharge lamp having an arc tube that discharges and emits light using microwave energy, wherein the arc tube is made of transparent quartz glass, and has a unit volume of light or at least 1. 4X10 gram atoms of 5 atoms to 4.24X10 gram atoms of mercury and IX 1
0' gram atom to 4X IO-7 gram atom of thallium and 2,3 X 10' gram atom to 1, 4X
10-'gram atom of sodium and 1゜I X 1
Indium from 0' gram atoms to 1.85X10-' gram atoms and from 9.3 X 10'' grams atoms to 8.
45X10-'gram atoms of halogen and 20t o
A starting rare gas of rr to 150 torr is sealed, and the microwave input per unit surface area of the inner wall of the arc tube is set in the range of 6 W to 60 W, and forced cooling is performed with cooling air. Electrode discharge lamp.