JPS6297298A - Non-electrode discharge lamp apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Technical Field) The present invention applies a high-frequency electromagnetic field to a bulb sealed with a rare gas or rare gas and metal vapor, discharges the gas inside the bulb, and emits light due to this discharge. Alternatively, the present invention relates to a so-called electrodeless discharge lamp device in which ultraviolet rays generated by this discharge are converted into visible light using a phosphor.

(Background Art) Incandescent light bulbs, which are currently widely used as light sources for illumination, have major drawbacks such as low efficiency and short lifespan. Electrodeless discharge lamps are one type of lamp that eliminates these drawbacks and can replace incandescent light bulbs, which are small light sources.

Electrodeless discharge lamps do not require electrodes, so they have a long life and are highly efficient, and are being researched in various places. FIG. 1 shows an example of such a conventional electrodeless discharge lamp, which has a structure in which a fluorescent material 1 is coated on the inner wall surface, and a metal vapor such as mercury and an inert gas such as argon are filled inside. Enclosed valve 2
It consists of an induction coil 3 wound around the outer circumference of the valve 2, a high frequency oscillator 4 for applying high frequency to the induction coil 3, and a power supply 5. The ultraviolet light emitted by ionizing the metal vapor such as mercury in the bulb 2 is converted into visible light by the fluorescent material 1 coated on the inner wall surface of the bulb 2, and is emitted from the bulb 2.

By the way, when a saturated vapor pressure lamp like a general fluorescent lamp is used as a lamp, the light output changes depending on the temperature of the tube wall, and in particular, the light output at low temperatures below 0°C is extremely low compared to at room temperature. It is well known that the starting characteristics also deteriorate, making it difficult for the lamp to light up at low temperatures.Such characteristics are also the same for the above-mentioned electrodeless discharge lamps, and the lamp 8 does not light up at low temperatures. Another problem is that even when the light is turned on, the light output is extremely low compared to that at room temperature, and it takes time to obtain stable light output.

(Objective of the Invention) The present invention has been made in view of the above-mentioned problems.The purpose of the present invention is to suppress the reduction in light output during cold start and to achieve uniform light output without being greatly affected by the ambient temperature. An object of the present invention is to provide an electrodeless discharge lamp device.

(Disclosure of the Invention) The present invention will be described below based on Examples. FIG. 2 shows an embodiment of the present invention, which differs from the conventional example shown in FIG. , and the changeover switch 7 is connected to the branch point.

Here, until the lamp 8 lights up, the selector switch 7
By placing the auxiliary coil 6 on the auxiliary coil 6 side, the high frequency output of the high frequency oscillator 4 is transmitted to the auxiliary coil 6. and,
When the lamp 8 is lit, the high frequency output is transmitted to the induction coil 3 by switching the changeover switch 7 to the induction coil 3 side.

Therefore, the inductance value of the auxiliary coil 6 is set smaller than the inductance value of the induction coil 3 to such an extent that although the high frequency oscillator 4 oscillates, the high frequency voltage induced in the auxiliary coil 6 is below the starting voltage of the lamp 8. . By setting the inductance value of the auxiliary coil 6 in this way, the high-frequency power supplied to the auxiliary coil 6 will prevent the lamp 8 from lighting before the lamp is lit, but the wall surface temperature of the lamp bulb 2 will be lowered due to the ohmic loss of the auxiliary coil 6. rises. As a result, the mercury vapor pressure inside the bulb 2 increases, making it easier to light up even at low temperatures, increasing the luminous flux immediately after lighting, and improving the start-up characteristics until stable light output is achieved.

Although the auxiliary coil 6 does not necessarily have to be wound around the bulb 2, it is desirable to wind it around the bulb 2 in consideration of heat conduction effects, reduction of generated noise, and the like.

Further, the position at which the valve 2 is wound around the valve 2 is not limited to the lower part of the valve 2 as shown in FIG. 2, but may be wound at a position as shown in FIG. 3. That is, the embodiment shown in FIG. 3 is characterized in that an exhaust pipe 9 is connected to the lower part of the valve 2, and an auxiliary coil 6 is wound around the exhaust pipe 9. With this configuration, the exhaust pipe 9 can obtain the same effect as in the previous embodiment, that is, the effect of raising the pipe wall temperature by the minute current flowing through the wound auxiliary coil 6 at low temperatures, and the lamp 8 Since no current flows through the auxiliary coil 6 during lighting, the coldest point of the lamp 8 occurs at the tip-off portion of the exhaust pipe 9, and the effect of controlling the coldest point of the lamp 8 can also be obtained.

(Effects of the Invention) As described above, the present invention causes a discharge body made of a rare gas or a rare gas and metal vapor sealed inside the bulb to emit light by supplying high-frequency power to an induction coil wound outside the bulb. In the electrodeless discharge lamp device, an auxiliary coil is arranged in parallel with the induction coil via a switch, and the inductance value of the auxiliary coil is set to
The auxiliary coil is characterized in that the high-frequency voltage induced in the auxiliary coil is set to be smaller than the induction coil so that it is below the lamp starting voltage, and the auxiliary coil is supplied with high-frequency power by a changeover switch before lighting the lamp. By supplying the light to the induction coil after lighting, it becomes easier to light even at low temperatures, the luminous flux immediately after lighting increases, and the rise characteristics until stable light output is achieved are also improved.

Therefore, according to the present invention, it is possible to suppress the reduction in light output during low-temperature startup, and to obtain a uniform light output without being greatly influenced by the ambient temperature.

[Brief explanation of drawings]

Fig. 1 is a simplified partial cross-sectional configuration diagram showing a conventional example, Fig. 2 is a simplified configuration diagram showing an embodiment of the present invention, and Fig. 3 is a sectional view showing main parts of a different embodiment of the present invention. be. 2... Valve, 3... Induction coil, 4... High frequency oscillator, 6... Auxiliary coil, 7... Changeover switch.

Claims (1)

[Claims] (1) In an electrodeless discharge lamp device in which a discharge body enclosed within a bulb emits light by supplying high-frequency power to an induction coil wound outside the bulb, a switch is used to switch an auxiliary coil in parallel with the induction coil. An electrodeless discharge lamp device characterized in that the inductance value of the auxiliary coil is set smaller than that of the induction coil so that the high frequency voltage induced in the auxiliary coil is below the lamp starting voltage. .