JPS59201360A - Fluorescent lamp - Google Patents

Abstract

PURPOSE:To supply the amount of mercury required for forming desired amalgam into an airtight container and provide the fluorescent lamp with stable characteristics by incorporating an alloy that forms the amalgam whosecomponents are indium and bismuth in the airtight container together with a mercury emission frame body. CONSTITUTION:An alloy that forms amalgam whose components are indium and bismuth is incorporated in a transparent airtight container together with a mercury emission frame body and an electrode to which an electron emission material adheres is provided on both ends of the airtight container. For example, as the said alloy, an alloy consisting of indium bismuth, and tin or an alloy consisting of indium, bismuth, and lead is used. In addition, for example, as the mercury emission frame body, a Ti3Hg alloy, such as commercial name GEMEDIS manufactured by SAES Co. is used. As a result, the required amount of mercury is stabilized in the airtight container and the required amount of mercury is emitted by the temperature in the airtight container when the fluorescent lamp is operated. The alloy and amalgam are formed and the mercury vapor pressure of the fluorescent lamp can be maintained in a suitable value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in the structure of a fluorescent lamp that exhibits less reduction in luminous flux even in a subtemperature atmosphere.

[Technical background of the invention and its problems]

Low-pressure mercury vapor discharge lamps such as fluorescent lamps have a mercury vapor pressure of 6 x 10-3 to 7 x in their airtight container.
When the discharge current is relatively low at 10-3 mmH,P.

It is known that the efficiency with which the supplied electrical energy is converted into mercury's 253.7 nm ultraviolet radiation is highest. Since the radiation in the ultraviolet region of 253.7 nm has a high phosphor excitation efficiency, the above 6 X 10-3 to 7 X
It is preferred to maintain the mercury vapor pressure at 10-3 mmHg, at which time the temperature of the wall of the airtight container is approximately 40°C. However, low-pressure mercury vapor discharge lamps such as fluorescent lamps
In recent years, there has been an increase in the use of cylindrical tubes with smaller pipe diameters that place more load on the walls of airtight containers, and the temperature of the walls of some airtight containers can exceed 100°C. When the wall temperature of the airtight container becomes high as described above, the mercury vapor pressure in the airtight container becomes significantly higher than about 6 X I F" mmHJ9, and the mercury vapor pressure radiated is 253.7
Radiation in the ultraviolet range, mainly nm, is self-absorbed by mercury, and the conversion efficiency of supplied electrical energy to radiation in the ultraviolet range decreases.

Therefore, there was a problem that the optical output decreased.

As a countermeasure to this problem, a fluorescent lamp was proposed in which an alloy mainly consisting of indium and bismuth was sealed together with mercury in an airtight container. In this fluorescent lamp, the alloy forms amalgam with mercury in an airtight container, so in a method where amalgam is placed in an airtight container, the amalgam is heated during the exhaust process of the fluorescent lamp, mercury is discharged, and the composition of the amalgam is Although there is little disadvantage that the mercury content fluctuates and the characteristics vary, it is difficult to keep the amount of mercury constant in the airtight container, and therefore the composition of the 7 malgam formed in the airtight container varies, emitting a stable and high luminous flux. No effect was obtained.

[Purpose of the invention]

The present invention was made in order to solve the problems of the above-mentioned back drilling technology, and it is possible to produce an improved fluorescent material with stable characteristics by supplying the necessary amount of mercury to form a desired amalgam in an airtight container. The purpose is to provide lamps.

[Summary of the invention]

The present invention emits mercury in a light-transmitting airtight container.

This fluorescent lamp contains an amalgam-forming alloy mainly composed of indium and bismuth, and has electrodes on both ends of the airtight container covered with electron emitting material.

[Embodiments of the invention]

The details of the present invention will be described.

The present inventors have developed an alloy consisting of indium, bismuth, and soot as an alloy forming an amalgam mainly composed of indium and bismuth.

(hereinafter referred to as "alloy (I)") and indium.

An alloy consisting of bismuth and lead (hereinafter referred to as "alloy (■)")
It is called. ) was tested. The present inventors housed the alloy (I) or alloy (n) in an airtight container.

Mercury is dropped into an airtight container as in the past.

Furthermore, changes in the initial luminous flux were tested by changing the surface temperature of the airtight container of a fluorescent lamp in which only mercury was dropped into the airtight container without using the above alloy.

The results are shown in Table 1. The maximum initial luminous flux is 10
It is expressed in specific luminous flux (%), which is set to 0. Curve (a) shows the characteristics of alloy (I) and mercury dropped. Curve (b) shows the alloy (■) and mercury dropped. Curve (c) shows the characteristics of mercury only. As is clear from Figure 1, curves 9 (a) and (b) have a luminous flux of 8 to 83 when the surface temperature of the airtight container reaches 60°C or higher, compared to the curve for mercury only (c).
% improvement.

However, it has been found that when the amount of mercury sealed in the airtight container changes, the luminous flux changes significantly as shown in the second diagram. That is, FIG. 2 is a characteristic curve diagram in which the horizontal axis represents the weight (In9) of mercury sealed in an airtight container, and s@a represents the specific luminous flux.

Curve 1) shows the characteristics of the fluorescent lamp with all units (1) and daffodil removed, and curve (A) shows the characteristics of the fluorescent lamp with alloy (II) and mercury added. When the amount of mercury increases and becomes more than 101n9, the luminous flux of the alloy (11) decreases.

When the amount of mercury exceeds about 151n9, the luminous flux starts to decrease even in those using alloy (II), and when the amount of mercury increases to about 20 to 25 mg, the luminous flux decreases to about 30 to 70% of the maximum luminous flux. This is thought to be due to the variation in the amount of mercury in the airtight container as mentioned above in the technical background problem, and the fact that a small amount of impure gas such as air is introduced when the alloy is introduced into the airtight container. It will be done.

The present inventors used the above alloy (1) or alloy (If).

Additionally, a mercury emitting structure, such as 5AE, can be used as a mercury source.
A fluorescent lamp was manufactured and tested by a method in which a Ti3H9 alloy such as GEMEDIS (trade name, manufactured by Company S) was disposed in an electrode structure, and after completion of the fluorescent lamp, high frequency heating was performed to liberate mercury.

In Figure 3, the horizontal axis represents the lighting time (hours) of the fluorescent lamp.
It is a characteristic curve diagram in which the luminous flux maintenance rate (%) is plotted with the initial luminous flux as 100 on the vertical axis, and each characteristic curve is a characteristic of a fluorescent lamp having the configuration shown in the table below.

As is clear from Table 3, a fluorescent lamp with the characteristics shown in the nine curves (M and (N)) has an initial luminous flux of 9 at 2,000 hours.
It showed a luminous flux of 1 to 92%, and even after 3,000 hours, it showed a luminous flux of about 88 to 88.5%. In contrast, conventional fluorescent lamps with the characteristics shown in curves (f), (g), and (g) have an initial luminous flux of 84 to 87.5% at 2,000 hours and 80 to 85.2% at 3,000 hours. %
As shown in the figure, the decrease in luminous flux is noticeable.

This means that by using a mercury release structure such as GEMEDIS, the amount of mercury in the airtight container is stabilized, and that the temperature inside the airtight container when the fluorescent lamp is operating releases the missing mercury, forming alloys and amalgams. and adjust the mercury vapor pressure of the fluorescent lamp to a suitable value of 6 x 10-3 to 7 x
It can be maintained at 10-3 mmHg. It seems to be for a reason. That is, the fluorescent lamp having the characteristics of the curve (male and ■) in FIG. 3 above is an embodiment of the present invention. The above-mentioned fluorescent lamp of the present invention not only has improved initial luminous flux and luminous flux maintenance rate, but also results in that the discharge starting voltage does not increase and the stabilization time of the light output is short. As mentioned in the technical background of the invention, in the fluorescent lamps used in recent fluorescent lamps, which have a small tube diameter and a high load on the tube wall where the tube wall temperature of the airtight container is 100 degrees Celsius or more, the above-mentioned indium and bismuth are used. In the vicinity of the location where the alloy mainly composed of is present, the temperature rises to at least 60°C and not more than 150°C. Therefore, the amalgam of the above alloy is the above 6
Preferably, the mercury is released between 0 and 150°C, which corresponds to the solid-liquid coexistence temperature of the alloy. As an alloy having a solid-liquid coexistence temperature of 60 to 150°C.

Examples include alloys of indium, bismuth, and soot, or indium, bismuth, and lead.

4 to 50% by weight of indium and 30 to 72% by weight of bismuth with 15 to 57% by weight of tin, or the above tin and 1 to 12% by weight of lead, or the above indium and bismuth with 5% to 40% by weight of lead. There are other alloys that can be used to form the amalgam of the present invention. According to experiments by the present inventors, in a fluorescent lamp in which the above-mentioned mercury release structure and indium are housed in an airtight container, when the tube diameter of the fluorescent lamp becomes smaller and the tube wall load of the airtight container is large, the mercury release structure and indium are removed from the mercury release structure. In the indium amalgam formed by the released mercury, the amount of mercury released from the amalgam is poorly controlled, and more mercury than the required amount of mercury is released, making it impossible to improve the decrease in optical output.

The method of incorporating an amalgam-forming alloy mainly composed of indium and bismuth in an airtight container is as follows:
Alternatively, the alloy may be fixed at a position relatively distant from the electrode, or fine particles of the alloy may be introduced together with the inert gas when introducing the inert gas into the fluorescent lamp.

〔Effect of the invention〕

The present invention is a fluorescent lamp characterized in that an amalgam-forming alloy mainly composed of indium and bismuth is housed in an airtight container together with a mercury release structure, and the mercury release structure increases the temperature of the wall of the airtight container. However, the amount of mercury in the airtight container can be controlled to the required amount, and therefore the composition of the amalgam, an alloy mainly composed of indium and bismuth, formed in the airtight container can be controlled to the desired value. Even if the temperature of the hermetic container of the fluorescent lamp is high, the supplied electrical energy can be efficiently converted to mercury's 253.7 nm ultraviolet radiation.

Therefore, it is possible to emit a stable and high luminous flux,
Furthermore, it has the effect of providing the industry with an improved fluorescent lamp that can maintain a low discharge starting voltage and has a short light output stabilization time. In the example, the alloy mainly composed of indium and bismuth was explained as an alloy to which soot and lead were added, but it is not limited to the example, and the above-mentioned alloy whose solid-liquid coexistence temperature of the 9 alloys is 60 to 150 ° C. In other words, the same effects as those of the embodiments can be achieved. Furthermore, the mercury release structure is not limited to the Gh:MgDIS shown in the examples.

[Brief explanation of drawings]

In Figure 1, the horizontal axis shows the wall temperature ('C) of the airtight container of the fluorescent lamp, and the vertical axis shows the specific luminous flux (%) with the maximum value of the initial luminous flux as 100.
) is a characteristic curve diagram of a fluorescent lamp containing an alloy mainly composed of indium and bismuth and dripping with mercury.The horizontal axis represents the amount of mercury (In9) in the airtight container, and the vertical axis represents the specific luminous flux. (%) Characteristic curve diagram of the above fluorescent lamp, Part 3
The figure is a characteristic curve diagram in which the horizontal axis represents the lighting time (hours) of the fluorescent lamp and the vertical axis represents the luminous flux maintenance rate (%). (7317) Agent Patent Attorney Noriyuki Chika (and 1 other person)

Claims (1)

[Claims] A translucent airtight container is provided with electrodes coated with an electron emitting material at both ends thereof, and a mercury emitting structure and an amalgam-forming alloy mainly composed of indium and bismuth are built in the airtight container. A fluorescent lamp characterized by: