JP2508679B2 - Electrodeless discharge lamp device - Google Patents

Description

Description: TECHNICAL FIELD The present invention encloses a gas body such as rare gas or metal vapor in a translucent valve, and applies a high frequency voltage to a coil arranged outside the valve, The present invention relates to a so-called electrodeless discharge lamp device in which a gas body in a bulb is discharged, and light emitted by the discharge is converted into visible light by a fluorescent body coated on the inner wall of the bulb.

[Background Art] An electrodeless discharge lamp does not have an electrode inside a bulb and is intended to discharge and emit light by externally applying a high-frequency electromagnetic field. FIG. 3 shows a conventional example of such an electrodeless discharge lamp, which has a structure in which a rare gas such as mercury vapor and argon is placed in an airtight space formed by a spherical bulb 1 having airtightness and translucency. A high-frequency power supply 4 is provided in which a fluorescent gas (not shown) is applied to the inner surface of the bulb 1 and an induction coil 2 is wound around the outer circumference of the bulb 1 while enclosing a discharge gas body such as The output of the oscillator 3 is given to the induction coil 2, and a high frequency electromagnetic field is generated from the induction coil 2. The high frequency electromagnetic field generated by the induction coil 2 causes discharge in the internal space of the valve 1. The ultraviolet light generated by the discharge is converted into visible light by the fluorescent body to obtain illumination light.

Such an electrodeless discharge lamp has features that it does not require preheating of the electrodes and can be instantly lit, has no wear of the electrodes and electrode materials, has a long life, and can achieve high output. In addition, the electrodeless discharge and the like can take various shapes without being limited to the spherical shape as in this example. Especially, when a linear or rod-shaped light source is required, the glass tube should have an appropriate length. It can be easily manufactured by cutting to form the bulb 1. As an example of electrodeless discharge of the rod-shaped lamp bulb 1, as shown in FIGS. 4 and 5, an induction coil 2 is wound in the longitudinal direction of the bulb 1 and a high-frequency current is passed through the coil 2. As shown in the figure, there is a valve 1 in which an induction coil 2 is spirally wound and a high-frequency current is passed through the coil 2.

By the way, when the electrodeless discharge is performed, the lamp bulb 1 is generally used.
Is very hot, and the temperature of the coldest part thereof is much higher than the coldest spot temperature corresponding to the mercury vapor pressure where the light conversion efficiency is optimum. Therefore, as shown in FIGS. 7 and 8, the coldest spot temperature is often lowered by providing a mercury reservoir 5 in a part of the bulb 1. When the mercury reservoir 5 is provided in this way,
Mercury collects in the mercury reservoir 5 at the time of lighting, and the temperature of the discharge space in the bulb 1 is high, so that the mercury vapor is extremely diluted. Therefore, most of the mercury is 5 when the light is turned off.
Therefore, there is a problem that when the light is turned on again, the rising characteristic is poor, that is, stable light output cannot be obtained in a short time.

[Object of the Invention] The present invention has been made in view of the above problems, and an object of the present invention is to provide a rising characteristic even in an electrodeless discharge in which a metal reservoir such as a mercury flow is provided in order to obtain a strong light output. It is to provide a good electrodeless discharge lamp device.

DISCLOSURE OF THE INVENTION The present invention relates to an electrodeless discharge lamp device in which a high frequency voltage is applied to a coil arranged outside a lamp bulb to discharge and emit a gas body to be discharged enclosed in the bulb. The valve is provided with a metal reservoir, and when the metal reservoir is turned off, it is preheated by a heater to improve the rising characteristic.

Hereinafter, the present invention will be described based on examples. FIG. 1 shows an embodiment of the present invention, in which a rare gas such as argon or a metal vapor such as mercury is filled in a lamp bulb 1 made of glass, which is hermetic and transparent and has a circular cross section. As a discharge gas body, a fluorescent body (not shown) for converting ultraviolet rays into visible light is applied to the inner wall of the bulb 1 as needed. At both ends of the bulb 1, mercury reservoirs 5a and 5b as metal reservoirs having a diameter sufficiently smaller than the bulb diameter are provided.
A preheating heater 6 is provided in each of the mercury reservoirs 5a and 5b.
a and 6b are provided. The induction coil 2 is wound along the outer surface of the valve 1 in the longitudinal direction, and a high frequency current is supplied to the coil 2 via a high frequency oscillator 3. 4 is a power supply.

In the electrodeless discharge lamp device configured as described above, when a high frequency current of 1 MHz or more flows through the induction coil 2 by the high frequency oscillator 3 connected to the power source 4, a dynamic magnetic field is generated around the induction coil 2. Induction of electrolysis causes discharge in the bulb 1. During this discharge, that is, while the lamp bulb 1 is on, only one mercury reservoir 5a is preheated by the heater 6a. Then, the other mercury reservoir 5b becomes the coldest part, and mercury accumulates in the mercury reservoir 5b. Next, at the moment when the discharge ends, the heater 6a is turned off and the other heater 6b is turned on to start preheating the mercury reservoir 5b. Then, the mercury accumulated in the mercury reservoir 5b becomes vapor and comes out into the bulb 1. At that time, when the light is turned on again, a sufficient amount of mercury vapor exists in the discharge space, so that the rising characteristics are improved. Also, at the moment when it goes out, the heater 6a
Turn on the heater 6a. Therefore, if controlled by an appropriate control circuit so that the above-mentioned operations occur alternately, it is possible to provide an electrodeless discharge lamp device having good rising characteristics.

Next, FIG. 2 shows a different embodiment of the present invention.
The difference from the above-mentioned embodiment is that the induction coil 2 disposed in the valve 1 is divided, and the induction coils 2a, 2b, 2c are divided.
The mercury reservoirs 5a, 5b, 5c are provided in the valve portions 1a, 1b, 1c corresponding to the above, and the preheat heaters 6a, 6 are provided in the respective mercury reservoirs 5a, 5b, 5c.
b and 6c are provided. Since other configurations are the same as those in the above-described embodiment, the description is omitted by giving the same reference numerals to the same configurations.

In such an embodiment, strong light emission occurs in each bulb portion 1a, 1b, 1c, and during lighting, mercury collects in each mercury reservoir 5a, 5b, 5c, and this portion becomes the coldest portion. When the mercury reservoirs 5a, 5b, 5c are preheated by the preheater heaters 6a, 6b, 6c at the moment when the lights are turned off,
The mercury accumulated in each of the mercury reservoirs 5a, 5b, 5c becomes vapor and emerges at the valve portions 1a, 1b, 1c. At this time, when the lamp is fully turned on, a sufficient amount of mercury vapor exists in the discharge space, so that the rising characteristics are improved.

[Advantages of the Invention] As described above, the present invention is an electrodeless electrode formed by discharging and emitting light from a gas body to be discharged enclosed in the bulb by applying a high frequency voltage to a coil arranged outside the lamp bulb. In the discharge lamp device, the upper bulb is provided with a metal reservoir such as a mercury reservoir, and the metal reservoir is preheated by a heater when the light is turned off. There is an effect that the metal vapor can be sufficiently supplied to the discharge space before and a strong light output can be obtained in a short time after lighting.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of the present invention, FIG. 2 is a schematic configuration diagram showing another embodiment of the present invention, and FIGS. 3 to 8 show conventional examples. 4, FIG. 6, FIG. 7 and FIG. 7 are schematic configuration diagrams respectively, and FIG. 5 and FIG. 8 are sectional views of the valve portion in FIG. 4 and FIG. 7, respectively. 1 ... Lamp bulb, 2 ... Coil, 5 ... Metal reservoir, 6
……heater.

Claims (1)

(57) [Claims] 1. An electrodeless discharge lamp device in which a discharge gas body enclosed in the bulb is discharged and emits light by applying a high-frequency voltage to a coil arranged outside the lamp bulb. An electrodeless discharge lamp device characterized in that a metal reservoir is provided and the metal reservoir is preheated by a heater when the lamp is turned off.