JPH043063B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a metal holding structure of a fluorescent lamp whose electrode structure includes a metal constituting an amalgam.

[Technical background of the invention and its problems]

The luminous efficiency of a fluorescent lamp decreases when the temperature of the coldest part of its translucent tubular airtight container rises above 40°C. For fluorescent lamps used in high-temperature environments, the temperature at the coldest part of the airtight container is often above 40°C, making it difficult to maximize luminous efficiency. The reason for this is that when the temperature of the coldest part of the airtight container rises above 40°C, some of the short wavelength ultraviolet rays emitted by mercury
More UV rays at 184.9 nm are emitted than UV rays at 253.7 nm.
This is because it is low at about %.

The temperature of the transparent tube-shaped airtight container of the fluorescent lamp is 40℃.
In order to prevent the luminous efficiency from decreasing even if the luminous efficiency increases, the mercury vapor pressure in the airtight container at that time should be kept at the appropriate value of approximately 6 microns. There is a method of sealing an amalgam that can maintain a mercury vapor pressure lower than that of mercury in a translucent airtight container. Examples of metals that form an amalgam with mercury include indium, indium-bismuth, and alloys such as indium-bismuth-lead.

Although this method can obtain a fluorescent lamp with high luminous efficiency because the mercury vapor pressure inside the airtight container in a high-temperature atmosphere is controlled, when starting the fluorescent lamp, the mercury vapor pressure is controlled to be low and the easily discharged electric material such as argon is used. The ratio to the gas pressure is 1/ of the appropriate value.
500 to 3/500, the so-called Benning effect does not function sufficiently and there is a problem that it becomes difficult to start the fluorescent lamp. Furthermore, it took time for the mercury vapor pressure in the airtight container to rise to an appropriate value, so the rise of the light output was slow, and it took time for the light output to stabilize. Moreover, such problems became especially problematic when the ambient temperature was low. As a countermeasure to this problem, a method has been proposed in which a metal member is placed on the amalgam in the stem to transfer the heat from the electrodes only during the initial lighting period of the fluorescent lamp, but it takes time to transfer the heat from the electrodes to the amalgam in the stem. In short,
Therefore, the release of mercury into the airtight container is slow;
It has been difficult to improve the starting characteristics.

[Purpose of the invention]

The present invention has been made to address the above-mentioned problems in the background art, and is directed to a fluorescent lamp in which an alloy that reacts with mercury in an airtight container to form an amalgam is enclosed in an airtight container. To provide an improved fluorescent lamp that is quickly stabilized and can maintain maximum luminous efficiency.

[Summary of the invention]

In the fluorescent lamp of the present invention, the electrode assembly of the stem sealed at both ends of the translucent tubular airtight container combines with mercury in the airtight container to form an amalgam at a position close to the electrode of the electrode assembly. If mercury is not sealed in a metal or airtight container, it is equipped with a thermally responsive element that holds the amalgam, and the thermally responsive element is configured to move in a direction away from the electrode when the temperature rises. It is characterized by

[Embodiments of the invention]

The details of the invention will be explained with reference to an illustrated embodiment.

FIG. 1 is a partially cutaway front view of an embodiment of the fluorescent lamp of the present invention, showing a straight tube-shaped light-transmitting airtight container of a glass bulb having a phosphor coating 1 formed by coating a phosphor on the inner surface. Stems 3 and 4 are sealed to both ends of 2. Lead wires 5, 5, 6, 6 planted on the stems 3, 4 are connected to electrodes 7, 8 of tungsten coil filaments whose coil portions are coated with an electron emitting material, thereby forming electrode structures 9, 10. has been done. Inside the translucent airtight container 2 is a stem 3 or 4.
The air inside the translucent airtight container 2 is exhausted through an exhaust pipe (not shown) provided in the container 2, and several torr. of easily discharged electric material such as argon and mercury are sealed, and then the exhaust pipe is sealed. Bases 11, 12 are glued to both ends of the airtight container 2, and the lead wires 5,
5, 6, and 6 are electrically conductively connected. On one of the stems 3 is a bimetallic thermally responsive element 1 that holds a metal constituting an amalgam, which will be described later, at its tip.
5 is supported and fixed by a support 16.

2 and 3 are enlarged views showing a portion of the electrode assembly on the side having the thermally responsive element of the fluorescent lamp according to the embodiment of the present invention, and the same parts as in FIG. 1 are given the same reference numerals. It is shown. Electrode structure 9
To the electrode 7 of the tungsten coil filament,
A bimetallic thermally responsive element 1 is placed close to one end thereof.
5 is fixedly supported at the other end by a support 16. The tip of the thermally responsive element 15 is bent and contains mercury and a metal 1 that constitutes an amalgam.
The bent edge 18 of the thermally responsive element 15 is provided with a gap 19 between the bent thermally responsive element 15 and the metal 17 constituting the mercury and amalgam from the gap 19. exposed.
In FIG. 3, the lead wire 5 is shown with a portion close to the stem 3 cut away. The thermally responsive element 15 is configured to move in a direction away from the electrode 7 as shown by a broken line as a thermally responsive element 15' when the temperature rises.

For example, when voltage is applied from the electrodes to a normal glow starter type fluorescent lamp lighting circuit, the current passes through a ballast to one electrode, and then the above electrode and the other electrode are connected in series via a glow starter, etc. flows into the circuit. When the electrodes of the fluorescent lamp are heated by the preheating current, the mercury in the airtight container 2 causes a local discharge between both ends of the electrodes. The metal 17 constituting the amalgam held at the tip of the thermally responsive element 15 provided close to one of the electrodes 7 constitutes the amalgam with mercury in the airtight container, and prevents heat from the heated electrode and local discharge. This makes it easier for discharge to occur inside the airtight container of the fluorescent lamp. Thereafter, when the electrodes of the glow starter are separated and the main discharge of the fluorescent lamp starts, the thermally responsive element is separated from the electrodes of the fluorescent lamp by the heat of the discharge. Therefore, in the fluorescent lamp of the present invention, since the amalgam is located close to the electrode at the time of startup, the ratio of mercury vapor pressure to argon gas pressure can be easily maintained at 1/500 to 3/500. As a result, starting time can be shortened.
Moreover, since the thermally responsive element is separated from the electrode while the fluorescent lamp is lit, the mercury vapor pressure inside the airtight container can be maintained at an appropriate value, thus maintaining the luminous efficiency of the fluorescent lamp at its highest value. It is possible. Further, since the thermally responsive element returns to the position shown in FIG. 3 15 when the fluorescent lamp is turned off, the fluorescent lamp can be properly lit by the above-described operation even when the fluorescent lamp is next turned on.

The present invention is not limited to the above embodiments, and the fluorescent lamp may be of a ring shape or a saddle shape other than a straight tube shape.
The present invention can also be applied to lamps having one or more curved parts, and may also be applied to rapid-start type fluorescent lamps. Further, the thermally responsive element may hold an amalgam itself of the above-mentioned metals other than the metals constituting the amalgam, such as indium, indium-bismuth alloy, etc. In this case, it is not necessary to seal mercury in the airtight container. .
Furthermore, the amalgam or the metal constituting the amalgam may not be directly held by the thermally responsive element, but may be held indirectly via another member. Furthermore, the metal holding structure provided at the tip of the thermally responsive element in close proximity to the electrode of the fluorescent lamp is not limited to the shape shown in the drawings, and the bent portion of the thermally responsive element may be cut out to expose the metal if necessary. You may expand the section. It goes without saying that the thermally responsive elements holding the metal may be provided on both electrodes of the fluorescent lamp.

[Effects of the Invention] The present invention provides a thermally responsive element that holds metal or amalgam constituting mercury and amalgam in a translucent airtight container in a position close to the electrode of an electrode assembly,
The fluorescent lamp is characterized in that the thermally responsive element is attached to the stem so as to move away from the electrodes when the temperature rises, and the lamp is mounted in an airtight container like a fluorescent lamp used in a high-temperature atmosphere. The present invention has the effect of providing an improved fluorescent lamp that can maintain maximum light efficiency even when the temperature exceeds the optimum value and has excellent characteristics without causing any problems in starting the fluorescent lamp. .

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view of the fluorescent lamp of the present invention.
2 and 3 are an enlarged front view and a side view showing a portion of the electrode structure of the fluorescent lamp shown in FIG. 1 on the side having a thermally responsive element. 2... Translucent airtight container, 3, 4... Stem,
7, 8... Electrode, 9, 10... Electrode structure, 15,
15'...Thermal response element, 17, 17'...Metal constituting the amalgam.

Claims (1)

[Claims] 1 Equipped with an electrode assembly having electrodes on stems sealed at both ends of a translucent tubular airtight container with a phosphor coated on the inner surface, and mercury and an easily discharged electric body, or an easily discharged electric body inside the airtight container. In the electrode assembly, the mercury in the airtight container and the metal constituting the amalgam, or the amalgam, are held in a position close to the electrode, and the amalgam moves in the direction away from the electrode when the temperature rises. A fluorescent lamp characterized in that a thermally responsive element is provided with an end supported by a stem.