JPH0113627B2 - - Google Patents

Description

Detailed Description of the Invention The present invention is directed to a starting aid disposed within a waveguide or within a microwave cavity in order to ensure the starting of an electrodeless discharge lamp lit within a microwave cavity. The present invention relates to a second method for manufacturing an electrodeless discharge lamp.

Conventionally, in a device with an electrodeless discharge lamp that is lit inside a microwave cavity, the impedance of the lamp differs greatly before and after the lamp is lit, so the impedance inside the microwave cavity changes when the lamp is lit. It is usually configured to match the impedance of the microwave oscillator. Therefore, when starting the lamp, little microwave energy can be supplied into the microwave cavity. Furthermore, the leakage electromagnetic field of the microwave that leaks slightly from the power supply port rapidly attenuates as it moves away from the power supply port, and is extremely weakened at the normal lamp installation position located at the center of the microwave cavity. For this reason, a lamp disposed in a microwave discharge light source device having such a configuration has the disadvantage that starting is uncertain.

In contrast, the present inventors have proposed that microwaves be placed near the feed port in a waveguide where a strong microwave electromagnetic field is formed even if the lamp does not start first, or in a microwave cavity where the strength of the leakage electromagnetic field is relatively strong. disposing a second electrodeless lamp lit by energy;
When the microwave is oscillated, first, a second electrodeless lamp (hereinafter referred to as the second lamp) is turned on,
By irradiating the electrodeless lamp (hereinafter referred to as the first lamp) that serves as the main light source with the ultraviolet rays emitted at this time, weak ionization is caused in the first lamp.
We have proposed a microwave discharge light source device that can be reliably started even by a weak leakage microwave electromagnetic field near the first lamp.

However, the second lamp in this light source device is smaller than the first lamp, and absorbs a large amount of microwave energy, especially until the first lamp reaches normal lighting, so it absorbs its own energy. There was a problem of frequent explosions caused by the heat of the discharge.

This invention was made in view of the above points,
In a second lamp that is intended to assist in starting the first lamp that is lit by a microwave electromagnetic field, in addition to the rare gas, mercury is sealed in the bulb in an amount that is below the saturated vapor pressure at room temperature, When manufacturing a second lamp that prevented bursting, the inside of the glass tube with one end closed was evacuated, mercury was kept at room temperature at the closed end, and the other end of the glass tube was closed at a certain interval, and then It is an object of the present invention to provide a manufacturing method that can efficiently manufacture a second lamp by cutting this blocked portion.

Embodiments of the present invention will be described in detail below.

The present inventors measured the reliability of starting the first lamp while changing the amount of mercury enclosed in the second lamp in the microwave discharge light source device proposed previously. It has been found that the reliability of starting does not depend on the amount of mercury sealed in the second lamp. This means that the amount of ultraviolet rays necessary to ensure the starting of the first lamp is discharged when mercury vapor exists in the second lamp at room temperature to an extent that the pressure is below the saturated vapor pressure. This indicates that the amount of ultraviolet rays emitted is below the amount that is emitted when We prototyped a second lamp filled with mercury that would be below the saturated vapor pressure at room temperature, and
The starting conditions of the lamp were observed with respect to the reliability of starting with and without a second lamp provided in the above-mentioned microwave discharge light source device. As a result, when the second lamp was not installed, the lighting rate was less than 60% for 100 flashes, whereas when the second lamp was installed, the lighting rate was 100%. It was confirmed that the amount of encapsulated mercury is sufficient at room temperature and below the saturated vapor pressure. Furthermore, it has been revealed that if the amount of mercury enclosed is below the saturated vapor pressure at room temperature, the absorption of microwave energy during operation will be small and the lamp will not explode.

Next, a second lamp manufacturing method according to the present invention will be explained with reference to the drawings. 1 to 4 are explanatory drawings showing the method of this invention in the order of steps, 1 is a transparent quartz glass tube, 2 is a closed section (hereinafter referred to as a seal section) formed in this glass tube 1 at a predetermined interval. )
In this case, we are doing press sealing. 3 is a light emitting part whose both ends are closed with seal parts 2;

First, as shown in Fig. 1, a long and narrow quartz glass tube 1 (inner diameter
3.5mmφ, outer diameter 5.5mmφ, length 150mm)
The open end side is attached to the exhaust device A, and after the entire baking process is degassed while evacuating the inside, argon at a predetermined pressure and 30 mg of mercury 4 are introduced into the inside. Next, the mercury 4 introduced into the quartz glass tube 1 is held at the closed end of the quartz glass tube 1. Next, the open end side of the quartz glass tube 1 opposite to the closed end is sealed and removed from the exhaust device A (FIG. 2). In this way, the elongated quartz tube 1, which is removed from the exhaust system A and which is closed at both ends, is vertically supported and placed at room temperature.
Press sealing is performed sequentially at predetermined intervals from the closed end where the mercury 4 is fixed and the opposite end (FIG. 3).
Next, the second lamp is completed by cutting the middle part of the press seal part 2 as shown in FIG.
Note that the lowest part of the quartz glass tube 1 having four mercury particles is not preferable as a second lamp.

Furthermore, in the above embodiment, before the elongated quartz glass tube 1 is successively press-sealed at predetermined intervals, the end opposite to the side that was previously press-sealed is press-sealed and removed from the exhaust device A.
It goes without saying that the step of press-sealing at predetermined intervals may be carried out with the elongated quartz glass tube 1 attached to the exhaust device A, and the sealing method is not press-sealing, but a large-scale sealing process while heating the sealing part. Of course, a method of sealing using atmospheric pressure may also be used.

As explained above, according to the present invention, in a device that radiates ultraviolet rays to the first lamp serving as the main light source using microwave energy, a simple configuration is possible in which the amount of mercury enclosed is kept below the saturated vapor pressure at room temperature. Therefore, it is possible to manufacture an electrodeless discharge lamp for starting assistance that is effective in preventing explosion without losing the starting assistance function. In addition, as a manufacturing method for this lamp, both ends of a quartz glass tube into which mercury has been introduced are closed off, the mercury is collected in one place inside the quartz glass tube, and the quartz glass tube is closed off at predetermined intervals, excluding areas where mercury accumulates. However, since the middle part of the closing part is cut after this, there is an advantage that it can be manufactured efficiently.

[Brief explanation of drawings]

1 to 4 are process diagrams showing a method for manufacturing an electrodeless discharge lamp according to the present invention in cross-section in the order of manufacturing steps. In the figure, 1 is a quartz glass tube, 2 is a closing part, 3 is a light emitting part, 4 is mercury, and A is an exhaust device. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] 1. After evacuating the elongated ultraviolet-transparent glass tube with one end closed, argon and mercury in an amount that would reach a saturated vapor pressure at room temperature are introduced into the glass tube, and then the other end of the glass tube is closed. , collect the above mercury in one place in the glass tube,
After this, the glass tube is closed at a predetermined interval at room temperature, except for the part where mercury accumulates, and then the middle part of this closed part is cut, both ends are closed, and mercury below the saturated vapor pressure is allowed to flow inside at room temperature. A method for manufacturing an electrodeless discharge lamp for starting aid, characterized by obtaining an encapsulated bulb.