JPS60193252A - Low pressure mercury vapor electric-discharge lamp - Google Patents

Abstract

PURPOSE:To widely improve the rising characteristics of a ow pressure mercury vapor electric-discharge lamp by restricting the area of a mercury getter coated with indium and its concentration to within specified ranges. CONSTITUTION:A mercury getter is installed in a high temperature area which is located closer to the electrode than the main amalgam. It is formed by coating a base member with indium. The area coated with indium and its concentration are restricted to within the region defined by lines connecting the coordinate point (4, 7.5), (20, 5.0X10<-3>), (120, 5.0X10<-5>) and (100, 4.0X10<-2>) in the domain determined by the area coated with indium (mm.<2>) (x axis) and the concentration of indium in a unit area of the coat (mg/mm.<2>) (y axis). A linear scale is used for the x axis and a logarithm scale is used for the y axis.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a low-pressure mercury vapor discharge lamp in which the mercury vapor pressure inside the tube is controlled by an amalgam.

[Technical background of the invention and its problems]

In a low-pressure mercury vapor discharge lamp, typically a fluorescent lamp, the tube wall temperature is around 40°C and the mercury vapor pressure is approximately 6
It is designed so that the efficiency of converting the supplied power into ultraviolet light is highest when the temperature is 10-'mnHg, and the lamp ambient temperature at this time is about 20-25°C. Therefore, when the ambient temperature significantly exceeds this value, the conversion efficiency of ultraviolet rays deteriorates rapidly, causing problems such as a decrease in light output.

By the way, in recent years, with the increase in the output of fluorescent lamps and the use of them in closed lighting equipment, the operating temperature of fluorescent lamps may become higher, and for this reason, the ambient temperature of one light rung should be set to the above value. There are many cases where the amount exceeds that of the conventional one, and a decline in light output and ultraviolet conversion efficiency has become a problem.

When a fluorescent lamp is operated under such severe temperature conditions, a method is adopted in which the mercury vapor pressure within the fluorescent lamp is controlled within an appropriate range using an amalgam. However, this method uses the property that the vapor pressure of amalgam is lower than that of pure mercury to control the mercury vapor pressure. If the ambient temperature of the b-light lamp is low, the temperature of the amalgam will be slow to reach the most desirable temperature for its operation, and the rate at which it will release mercury will be slow. Therefore, the rise of optical output is slow, and
A problem occurs that requires time to stabilize to a steady state.

For this reason, in addition to the main amalgam that controls the mercury vapor pressure during steady lighting, a small amount of auxiliary amalgam that temporarily supplies mercury vapor during the early stages of lighting, including during startup, is installed in a high-temperature area near the electrodes. However, there is a known device that improves the rise in light output at the initial stage of lighting, and this auxiliary amalgam acts as a mercury duck that adsorbs mercury when the light is turned off.

However, in a fluorescent lamp that uses two types of amalgam to control mercury vapor pressure, when the lamp is turned off, most of the mercury vapor in the tube is absorbed by the main amalgam, which has a large capacity. Since the mercury content of the amalgam is reduced, the amount of mercury released when the lamp is relit is small, and the light output starts up slowly.

In order to overcome these drawbacks, the
As shown in Publication No. 387, by specifying the surface area of the auxiliary amalgam to be at least 0.3 times the surface area of the main amalgam, the mercury floating in the tube after the lights go out is quickly absorbed by the auxiliary amalgam, and the mercury-containing There are known methods that prevent the amount from decreasing.

However, the present inventors have found from the results of various experiments that when the main amalgam and the auxiliary amalgam are installed in the above-mentioned positional relationship, simply defining the relative surface area ratio of the two amalgams does not result in light It has been found that there are times when the output start-up is good and times when it is worse.

That is, according to the above experiment, mercury vapor is adsorbed by the main amalgam when the lights are turned off, but if an auxiliary amalgam is present in the flow path of this mercury vapor, most of the mercury vapor will be adsorbed by the auxiliary amalgam. Therefore, the problem when the auxiliary amalgam adsorbs mercury vapor is not the relative surface area ratio with the main amalgam, but the surface area of the auxiliary amalgam itself is involved in the adsorption effect of mercury vapor, and It was found that the adhesion density of the auxiliary amalgam per unit area also plays a significant role. As this experiment progressed, it was confirmed that even if the surface area of the auxiliary amalgam was too large, the rise in light output upon relighting had a negative effect on the light output.

[Purpose of the invention]

The present invention was made based on these circumstances, and
The purpose of the present invention is to provide a low-pressure mercury vapor discharge lamp in which the rise 9 of light output at the time of relighting is performed almost instantaneously, and the rise characteristics can be greatly improved.

[Summary of the invention]

That is, in order to achieve the above-mentioned object, the present invention installs a mercury getter that adsorbs mercury in the arc tube when the light is turned off in a high-temperature area near the electrode as well as the main amalgam. (In) (auxiliary amalgam-forming metal) is used. On the x-y coordinate with the y axis, the indium deposition area and deposition concentration are (4°7
．． 5), (20,5,OXl 0-'), (
120,5,0X10 ), (100,4,0X10
) is defined within the range connecting each coordinate point.

However, the x-axis is a linear scale, and the y-axis is a semi-logarithmic scale.

[Embodiments of the invention]

The present invention will be explained below based on an embodiment shown in the drawings.

In the figure, reference numeral 1 denotes a cover made of synthetic resin, and a base 2 is attached to the top of one end of the cover 1.

The opening at the other end of the cover 1 is covered with a substantially spherical globe 3 having translucent properties, and the bulb 1 and the globe 3 form an envelope 4 that resembles a ball-shaped incandescent light bulb.
is configured.

Inside the envelope 4, a fluorescent lamp 5, which is a typical low-pressure mercury vapor discharge lamp, a lighting tube 6 as a starting element of the fluorescent lamp 5, and a choke coil type ballast 7 as a discharge stabilizing element are integrated. is accommodated. The luminous tube 8 of the fluorescent lamp 5 is made by bending a straight glass nozzle into a substantially U-shape at the center between the two ends 9.9, and the curved part 10 and the two ends 9.9. and is curved in a substantially U-shape in a direction substantially perpendicular to the plane containing the above-mentioned U-shape, and both ends 9, 9 and the curved part 10 are located adjacent to each other in the same direction. It is curved into a saddle shape. A phosphor coating 12 is coated on the inner surface of the arc tube 8, and both ends 9
．． The flare portion 14 of the mount 13 is sealed to the mount 9 as shown in FIG. An internal lead wire 16.16 is sealed in the stem tube 15 connected to the flare portion 14,
A filament 17 as an electrode is connected between these lead wires 16,16. Further, an exhaust pipe 18 led out from the stem pipe 15 is opened at the tip of the stem pipe 15 close to the filament 17, and an ionizable medium containing a predetermined amount of an inert gas is passed through the exhaust pipe 18. is enclosed within the arc tube 8.

The fluorescent lamp 5 is housed in the envelope 4 with both ends 9.9 and the bent portion 10 facing the base 2, and the lighting tube 6 and ballast are It is connected to the cap 2 via 7.

Incidentally, an amalgam 19 is housed in the exhaust pipe 18, which is also located on the pipe end side of the filament 17. In this case, the amalgam-forming metal and mercury may first be separately sealed in the amalgam 19, and the amalgam-forming metal may be amalgamated later.

The amalgam 19 is used to control the mercury vapor pressure inside the tube during steady lighting, and in this embodiment, it is made of indium (In), bismuth (Bl), tin (Sn), lead (PB), and these. An alloy made by mixing various metals in appropriate proportions with mercury (Hg) is used. Further, a mercury duck 2 is supported at the tip of the stem tube 15 via a support line 20. The mercury ivy 21 is made by depositing a small amount of indium (In) on the surface of a base 22 made of stainless steel, nickel, molybdenum, aluminum, chrome, or plate by plating or vapor deposition. It is desirable to contain approximately the same number of indium atoms as the number of atoms of mercury vapor sealed in the mercury vapor. The mercury duck 21 is located between the open end of the exhaust pipe 18 and the filament 17, and the amalgam 19 is also located in a high temperature area near the filament 17. When the temperature inside the tube is low, it adsorbs mercury vapor inside the tube, and conversely, when the lamp is turned on, it is affected by heat from the adjacent filament 17, and when the lamp is turned off, the adsorbed mercury is released.

In this configuration, when the cap 2 is now inserted into the socket on the power supply side and the power supply voltage is applied to the arc tube 8 to start it, the amalgam 19 housed in the exhaust tube 18 will be affected by heat due to the discharge. The temperature rises and mercury is released into the arc tube 8. The mercury vapor pressure inside the tube after the optical output has shifted to a steady state is controlled to a vapor pressure determined by the temperature of the part where the amalgam 19 is installed.

On the other hand, when the fluorescent lamp 5 in such an operating state is turned off, the temperature inside the arc tube 8 and the part where the amalgam 19 is installed decreases, so that the mercury vapor inside the arc tube 8 begins to be adsorbed by the amalgam 19. In this case, since the amalgam 19 is housed within the exhaust pipe 18, a flow of mercury vapor is formed within the arc tube 8 toward the open end of the exhaust pipe 18. At this time, the exhaust pipe 1 where mercury vapor collects
Since the mercury getter 21 is located near the open end of the exhaust pipe 18, a part of the mercury vapor flowing into the exhaust pipe 18 is efficiently adsorbed by the mercury getter 21, that is, indium.
The mercury content of isidium is sufficient.

Therefore, when the fluorescent lamp 5 is turned on again after being turned off, the mercury getter 21 that has adsorbed mercury vapor rapidly rises in temperature under the influence of heat from the adjacent filament 17, and promptly emits a sufficient amount of mercury. Discharge into tube 8. As a result, the time required for the optical output to rise properly and to rise can be shortened.

By the way, the present inventors investigated the mercury adsorption effect of indium used as the mercury paste 21, and found that the adhesion area of indium (,,'') and the unit of indium deposited on the base 22 Deposition concentration per area (rv
/+! ++12), it has been found that there is a correlation that affects the rise characteristics of optical output.

The basis for this will be explained below with reference to FIGS. 4 to 6. That is, FIG. 4 shows the amalgam 19 as a function of temperature.
．． This figure shows the changes in vapor pressure of indium and pure mercury used in mercury r2 and pure mercury.
'l A' shows the vapor pressure curve of indium, B shows the amalgam 19.C shows the vapor pressure curve of pure mercury, respectively.In addition, the vapor pressure curves A, A
'.

A'' has a different vapor pressure curve as a result of a difference in the mercury content ratio of indium, and the smaller the mercury content ratio, the more the vapor pressure curve shifts to the right. The mercury vapor pressure of the lamp is controlled by the amalgam 19 as shown in curve B. For example, even if the temperature during lighting is as high as about 80°C, the mercury vapor pressure is 6 x 10
-'If gum 19 were not present, the mercury vapor pressure would have the value shown by curve C. ) Now, when the fluorescent lamp 5 is turned off, the mercury vapor pressure of the amalgam 19 and indium is determined by the temperature after the lamp is turned off, and the floating mercury vapor pressure in the tube when the lamp is turned off (generally around 6 × 10-' mnHg ) The larger the differential pressure between the amalgam 19 and the indium, the higher the rate at which the amalgam 19 and indium adsorb mercury vapor in the arc tube 8). , much of the mercury vapor is adsorbed by indium.

At this time, if the concentration of indium deposited on the substrate 22 is high, the mercury content ratio of indium will be small and the vapor pressure curve will shift to A' in FIG. Therefore, assuming that the temperature is constant, the differential pressure between the tube and the mercury vapor pressure in the tube as shown by the vapor pressure curve C increases when the light is turned off, so that the rate at which indium adsorbs mercury vapor increases.

On the other hand, as is clear from Fig. 4, the vapor pressure shown by the vapor pressure curve A' is low at restart, so the release of mercury is slow, and as a result, although good adsorption takes place, light The output start-up becomes slow.

On the other hand, when the adhesion concentration of indium is reduced, the mercury content ratio of indium becomes large and the vapor pressure curve shifts to the lower temperature side to A" compared to the reverse KAK. Then, when the lights are turned off, the mercury vapor pressure inside the tube Because the differential pressure becomes smaller,
A part of the mercury floating in the tube is adsorbed by the amalgam 19 and stored away, and the proportion of mercury adsorbed by indium is relatively reduced. As a result, the mercury content in indium decreases. Therefore, the amount of mercury released when restarting is small.
Unfortunately, the start-up of the optical output is getting worse.

Therefore, based on these experimental results, the present inventors
More detailed experiments were conducted. i.e. amalgam 1
As 9, three types of metals, old-In-Hg, are used in a molar ratio of Bi:In=0.53:0.47Hg:
(Bi + In) = 0.032: 0.96
Using an alloy mixed in a ratio of 8 to 8, this alloy is
．． 0 mm and a surface area of 12.6 rtan" and sealed in the exhaust pipe 18, and a mercury film 21 made by adhering indium to molybdenum foil was attached to the open end of the exhaust pipe 18 and the filament. A 17W class fluorescent lamp 5 placed between the 17 and 17 was manufactured. Then, the indium deposition area of the mercury getter 21 was changed from 2 mm2 to 13 mm.
0w112 and varied the deposition concentration of indium per unit area in each case to compare the rise characteristics of the optical output.
The results shown in the figure were obtained. In this experiment, the rise characteristics of the light output were evaluated by the ratio of the light output 4 to 5 seconds after starting and the steady lighting.As is clear from Fig. 5 above, It has been found that in each case where the deposition area is defined, the rise 9 characteristic of the optical output becomes maximum when the deposition concentration is a certain value. The chain line S1 in FIG. 5 is
The rise level is higher than that of a normal fluorescent lamp that does not use amalgam, so in order to obtain a rise characteristic that is higher than that of a normal fluorescent lamp that does not use amalgam, it is necessary to deposit indium. It can be seen that it is necessary to specify the area within the range of 2 to 120 mm.At the same time, if the indium deposition area is specified to be 2 to 120 mm, 80% or more of the area is The indium deposition concentration required to obtain the top-side characteristics is indicated by the intersection of the above-mentioned broken line and the characteristic curve showing each rise-side characteristic, and when these intersections are plotted, the results are shown in Table 1 below. The value will be as follows.

Table 1 and the values of the above coating area and coating concentration are shown, with the coating area on the x-axis on a linear scale and the coating density on the semi-logarithmic scale on the y-axis.
On the axis! 7. When expressed on the X-7 coordinate, it becomes as shown in FIG. In this Figure 6, the coordinate point (120
, 5,OXl 0-5) and (20,5,0X10-3)
The line segment Q1 connecting the two points indicates the lowest level of indium deposition concentration for the deposition area at the coordinate point (100, 4, 0X
The line segment Q2 connecting the two points (10-2) and (4°7.5) also shows the highest level of deposition concentration), and the coordinate points (4°7.5) and (20,5) , 0X10-3), the minimum level of the deposition area for the deposition concentration is determined by the coordinate points (100, 4, 0X10-2) and (120
The line segment Q4 connecting the two points with ゜5xio-5) also represents the highest level.

Therefore, if the values of the indium deposition area and deposition concentration are set to be included in the range surrounded by each of the above line segments Q1 to Q4, the rise characteristics of the light output at the time of relighting will be as follows: It becomes possible to maintain at least the same level as a normal fluorescent lamp that does not use amalgam.

This means that when the light is turned off, indium efficiently adsorbs floating mercury inside the tube, and when the light is restarted, a sufficient amount of mercury is quickly released into the arc tube 8.)
Therefore, the rise of the optical output is performed almost instantaneously, and there is an advantage that the rise characteristic can be greatly improved and the reliability can also be improved.

In addition, as the amalgam, the above-mentioned nine B i -I n
In addition to -Hg, an alloy of B1-In-8n +B1-In-Pb combined with mercury is also considered, and it has been confirmed that the mercury adsorption effect of the mercury getter hardly changes even in other cases.

Furthermore, the discharge lamp according to the present invention is not limited to one that is housed in a light bulb-shaped envelope and used for lighting, but is also applicable to a discharge lamp that is not only used for lighting while being housed in a bulb-shaped envelope, but also for use in a lamp that is bluntly exposed to the outside like a general straight or curved fluorescent lamp. It can be similarly applied as a light source for a copier that lights up at a high frequency or that blinks frequently.

Moreover, the wattage was not limited to 17W, but even a wattage of about 40W showed almost the same results.

〔Effect of the invention〕

According to the present invention described in detail above, the mercury getter efficiently adsorbs floating mercury in the arc tube when the light is turned off, and the mercury content becomes sufficient, and when the lamp is restarted, the mercury content becomes sufficient due to the thermal influence from the electrodes. Since a large amount of mercury can be released into the arc tube quickly, the rise of the light output is almost instantaneous, so the start-up characteristics can be greatly improved, and reliability can also be improved. There are advantages to improving.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is an overall sectional view, FIG. 2 is a sectional view taken along line Nakata-n in FIG. 1, FIG. 3 is a sectional view of the tube end, and FIG. 6 through 6 are characteristic diagrams, respectively. 8... Arc tube, 17... Electrode (filament), 1
9...Amalgam, 21...Mercury getter, 22...
・Base. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Mouth■

Claims (2)

[Claims] (1) Inside the arc tube, which has electrodes sealed at both ends and an ionizable medium containing a predetermined amount of mercury, is placed closer to the end of the tube than the electrodes to measure the mercury vapor pressure inside the tube during steady lighting. This is a low-pressure mercury vapor discharge lamp which is provided with an amalgam to control and a mercury getter which is also located in a high temperature part near the electrode and adsorbs mercury in the arc tube when the light is turned off. Indium (In) is not deposited on the substrate. -7 coordinates, the deposited area and concentration of indium are (4,7,5), ('20.5.0X10-
'). (120,5,0X10-5), (100,4,0
A low-pressure mercury vapor discharge lamp characterized in that the lamp is defined within a range connecting each coordinate point of X10''''2). (However, the X-axis is a linear scale, and the y-axis is a semi-logarithmic scale.) (2) the amalgam is housed in the exhaust pipe of the arc tube;
Claim (1) characterized in that the mercury getter is located between the open end of the exhaust pipe and the electrode.
Low-pressure mercury vapor discharge lamps as described in .