JP2508348B2 - Electrodeless discharge lamp device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electrodeless discharge lamp device using a high-intensity electrodeless discharge lamp.

[Prior Art] FIG. 5 shows an example of a conventional high-intensity discharge lamp, in which a pair of electrodes 2a and 2b are arranged facing each other at both ends of an arc tube 1 made of quartz glass or the like. , The electrodes 2a, 2b are metal foils 4a, 4b such as molybdenum foil enclosed in the sealing portions 3a, 3b.
It is connected to the. The metal foils 4a and 4b are electrically connected to the support conductors 5a and 5b which also serve as the support of the arc tube 1 and are mechanically fixed. The support conductors 5a and 5b are connected to an external circuit via the base 6. Further, a rare gas and an appropriate amount of mercury and a metal halogen compound as a light emitting substance are enclosed in the arc tube 1, and a gas is enclosed in the outer tube 7 covering the arc tube 1. Such a high-intensity discharge lamp is widely used in factories, stores, gymnasiums, etc. as a white light source with high efficiency and high color rendering.

[Problems to be Solved by the Invention] By the way, in the high-intensity discharge lamp, the arc tube 1
The tube wall is heated and the enclosed luminescent material evaporates to emit a spectrum peculiar to this luminescent material. The vapor density of the luminescent material in the arc tube 1 is the lowest temperature of the tube wall ( Coldest spot temperature). For example, as other metal halogen compounds such as argon and mercury, Na I-Tl I
When a conventional high-intensity discharge lamp containing −In I is lit, the coldest spot temperature is determined, and Na
I, Tl I, In I evaporate and this emits light. In this case, as shown in FIG. 6, Na (main wavelength 589 nm; orange), Tl (main wavelength 53
5 nm; green), In (main wavelength 451 nm; blue) monochromatic light emission, as well as emission spectra of mercury at various wavelengths (365 nm, 405 nm, 436 nm,
546 nm and 577 nm) are also present. The emission color of the high-intensity discharge lamp is determined by the balance of the emission spectra of these enclosed substances.

The coldest spot temperature of the high-intensity discharge lamp is mainly determined by the distance between the arc generated between the electrodes 2a and 2b and the tube wall. In the conventional high-intensity discharge lamp, the electrodes 2a and 2b are sealed in the arc tube 1. Since it was worn and the distance between the arc and the tube wall was fixed, the cold spot temperature could not be controlled and therefore the emission color could not be changed.

The present invention has been made in view of the above problems, and an object thereof is to provide an electrodeless discharge lamp device capable of controlling the coldest spot temperature.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides an arc tube in which a plurality of metal halogen compounds are enclosed as a light emitting substance, and an electromagnetic field applying coil wound around the outer circumference of the arc tube. In an electrodeless discharge lamp device provided with a high-frequency power source for supplying a high-frequency current to the coil, the coldest spot temperature of the arc tube is changed by changing the relative position of the coil and the arc tube. , Changing the emission color.

[Operation] According to the present invention, by changing the relative position of the coil and the arc tube, the position of the arc generated in the arc tube is moved, and the emission color is changed. For example, by using an electrodeless high-intensity discharge lamp in which the above-mentioned luminescent material is enclosed, the coldest spot temperature rises by bringing the arc close to the coldest spot of the arc tube, and the spectrum of Na, which is a red component, increases. Further, when the arc is moved away from the coldest spot of the arc tube, the coldest spot temperature decreases, and the red component and the green component decrease.

[Embodiment 1] FIG. 1 shows a first embodiment of the present invention.
Reference numeral 10 denotes an arc tube in which a light emitting substance is enclosed. The enclosure substance is the same as in the conventional example, and Na I, Tl I and In I are enclosed as metal halogen compounds in addition to argon and mercury. Reference numeral 11 is an electromagnetic field applying coil wound around the outer circumference of the arc tube 10, 12 is a high frequency power source composed of a high frequency oscillator, 13 is a power amplifier circuit for amplifying the output of the high frequency power source 12, and its output ends are both ends of the coil 11. It is connected to the. Reference numeral 14 is a drive device as a means for changing the relative position of the arc tube 10 and the coil 11, and can move the arc tube 10 up and down.

In the electrodeless discharge lamp device configured as described above, the arc tube 10 emits light when a high-frequency current is applied to the coil 11.
At this time, the coldest spot is at the position indicated by symbol A in the figure. Then, by driving the driving device 14 to raise the position of the arc tube 10 with respect to the coil 11, the arc (not shown) approaches the coldest point A, and the coldest point temperature rises. When the coldest spot temperature rises, among the encapsulating substances Na I, Tl I, and In I, the evaporation amount of Na, which has the lowest evaporation amount due to the highest evaporation temperature, increases, and the red component of the emission color increases. . Conversely, by lowering the position of the arc tube 10 with respect to the coil 11, the arc moves away from the coldest point, and the coldest point temperature drops. When the coldest spot temperature decreases, the evaporation amount of Na and Tl decreases, and as shown in FIG. 3, the light becomes light in which the red component and the green component of the emission color are reduced. Therefore, by changing the relative positions of the arc tube 10 and the coil 11, the emission color can be changed. Note that FIG. 2 is an emission spectrum in the case where an arc is generated in the approximate center of the arc tube 1.

[Embodiment 2] FIG. 4 shows a second embodiment of the present invention. The difference from the above embodiment is that the means for changing the relative positions of the arc tube 10 and the coil 11 is the number of turns of the coil 11. Since the other configuration is the same as that of the above-described embodiment by being configured with the switch 14 for switching between, the description is omitted by assigning the same reference numerals to the same configurations.

Also in this example, the same results as in the above example were obtained. That is, when the switch 14 is connected to the b contact,
The red and green components of the emission color were reduced compared to when the light was connected to the contact.

[Effects of the Invention] As described above, the present invention makes it possible to control the coldest spot temperature by changing the relative positions of the electromagnetic field applying coil wound around the outer circumference of the arc tube and the arc tube, and to achieve the emission color. It was possible to provide an electrodeless discharge lamp device capable of changing

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of Example 1 of the present invention, FIGS. 2 and 3 are diagrams showing an emission spectrum according to Example 1 respectively, and FIG. 4 is an outline of Example 2 of the present invention. Figure, fifth
FIG. 6 is a front view of a partial cross section showing an example of a conventional high-intensity discharge lamp, and FIG. 6 is a diagram showing an emission spectrum according to the conventional example. 10 ... Arc tube, 11 ... Electromagnetic field applying coil, 12 ... High frequency power source, 13 ... Power amplification circuit, 14 ... Means for changing relative position of arc tube and coil.

Claims (1)

(57) [Claims] 1. An arc tube in which a plurality of metal halides are enclosed as a luminescent material, an electromagnetic field applying coil wound around the outer circumference of the arc tube, and a high frequency power source for supplying a high frequency current to the coil. In the electrodeless discharge lamp device, the temperature of the coldest spot of the arc tube is changed by changing the relative position of the coil and the arc tube to change the emission color. Electrode discharge lamp device.