JPS60208044A - Low pressure mercury vapor discharge lamp and manufacture thereof - Google Patents

Abstract

PURPOSE:To uniform the brightness at the initial stage of lighting by providing amalgam for controlling the mercury vapor in a tube at the tube end sections at the opposite sides of U-shaped light emission tube while providing mercury getter at the high temperature portions near both electrodes. CONSTITUTION:U-shaped light emission tube 8, a glow tube 6 and a ballast 7 are contained in a globe 3 to produce a small low pressure mercury vapor discharge lamp. Here, amalgams 20, 21 of such as indium for controlling the mercury vapor pressure in the tube under lighting are arranged in thin tubes 18,19 at the opposite ends of said tube 8. The amalgam 20 is made spherical while a coil spring 22 applied with indium is employed as the amalgam 21 while first and second mercury getters 22, 23 are welded to the leads 16 of both electrodes 17. Since the mercury is discharged uniformly from the opposite ends of the discharge space into said tube 8, the initial brightness is uniformed resulting in improvement of the rising characteristic of the light output.

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, and a method for manufacturing the same.

[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 electric power into ultraviolet light is the highest when the temperature is 10''-'ILIHg, and the lamp ambient temperature at this time is about 20 to 25 degrees Celsius.

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 sealed lighting equipment, the operating temperature of fluorescent lamps may become higher, and as a result, the ambient temperature of the fluorescent lamp may exceed the above value. There are many opportunities for this, and the problem is that the light output and ultraviolet conversion efficiency decrease.

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 characteristic 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 lamp is low, the temperature of the amalgam will be slow to reach the most desirable temperature for its operation, and the rate of mercury release will be slow. Therefore, the rise of optical output is poor,
A problem occurs that requires time to stabilize to a steady state.

Because of this, conventionally, for example,
As shown in Publication No. 87, in addition to the main amalgam that controls mercury vapor pressure during steady lighting, mercury vapor is temporarily released at the initial stage of lighting, including at the time of starting, and when the lights are turned off, floating mercury in the tube is released. It is known that a small amount of auxiliary amalgam that adsorbs light is placed in a high-temperature part near the electrode to improve the rise characteristics of optical output.

What has the function of improving the rise characteristics is not limited to the auxiliary amalgam, that is, the amalgam-forming metal placed near the electrode, but may also be a substance that physically adsorbs mercury when the light is turned off. This has been discovered through research by the present inventors. Therefore, the present inventors refer to the above-mentioned auxiliary amalgam or physical adsorption substance as a mercury getter because it has the function of adsorbing floating mercury in the tube when the lights are turned off.

By the way, according to the above-mentioned prior art, it was possible to shorten the rise time of the light output at the time of starting, but the light emission started from the part where the auxiliary amalgam was installed, and the whole area gradually became brighter. The non-uniformity of the luminance distribution over time was found to be a drawback. Therefore, an attempt was made to improve this non-uniformity by installing auxiliary Amargano near both electrodes, but the non-uniformity of the brightness distribution during startup still remained. These drawbacks are not limited to when auxiliary amargano is used as the mercury getter, but become more pronounced when the mercury getter has only the above-mentioned physical adsorption effect. That is, according to various experiments conducted by the present inventors, when the main amalgam that controls the mercury vapor pressure inside the tube during steady lighting is attached to the stem of one electrode as in the above-mentioned prior art, this main amalgam Since the amalgam is located toward one end of the discharge space, if the auxiliary amalgam as a mercury getter is installed near one of the electrodes, or even when it is installed near both electrodes, the amalgam volume on the side toward one electrode will be smaller. Therefore, when the lamp is turned off, the suspended mercury in the pipe becomes
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Most of the suspended mercury is adsorbed by the auxiliary amalgam on the main amalgam side.

As a result, the mercury content in the auxiliary amalgam on the opposite side decreases, so when the lamp is restarted, the release of mercury into the arc tube begins from the auxiliary amalgam on the main amalgam side, and the ionization also occurs at one end of the arc tube. It was discovered that the luminance distribution becomes non-uniform in the initial stage of lighting.

[Purpose of the invention]

The present invention was made based on these circumstances, and
A first object of the present invention is to provide a low-pressure mercury vapor discharge lamp that can uniformize the brightness at the initial stage of lighting.

Furthermore, in manufacturing a low-pressure mercury vapor discharge lamp that achieves the above object, the present invention provides a method for manufacturing a low-pressure mercury vapor discharge lamp that does not cause the main amalgam to melt or oxidize during the evacuation process of the arc tube. The second purpose is to provide information.

[Summary of the invention]

That is, the first p-h that achieves the above first purpose
, a main amalgam that controls the mercury vapor pressure in the tube during steady lighting is installed on the end side of the electrodes at both ends of the arc tube, and a high-temperature area near the electrodes is installed in the arc tube when the light is turned off. It is characterized by the installation of a mercury getter that adsorbs floating mercury and releases the adsorbed mercury at startup.

A second invention to achieve the second object is a low-pressure mercury vapor discharge lamp according to the first invention, in which both main amalgams have different compositions and are installed in their respective thin tubes. A method for manufacturing an electric lamp, which includes the steps of sealing mounts on both ends of an arc tube with mercury getters installed in advance near the electrodes, and placing a main amalgam with a high melting point composition in the thin tube of one mount. At the same time, after this installation, the inside of the arc tube is evacuated through the capillary of the other mount, and after this evacuation, a main amalgam with a low melting point composition is installed in the capillary of the other mount, and after this evacuation, It is characterized by comprising a step of sealing an inert gas and, if necessary, mercury into the arc tube.

[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 other end opening of the cover 1 is covered with a substantially spherical globe 3, and the cover 1 and the globe 3 constitute an envelope 4 that approximates a ball-shaped incandescent light bulb.

Inside the envelope 4, a fluorescent lamp 5, which is a typical low-pressure mercury vapor discharge lamp, a lighting tube 6 as a starter for the fluorescent lamp 5, and a choke coil type ballast 7 as a discharge stabilizing element are integrated. is accommodated. In the luminous tube 8t of the fluorescent lamp 5, a straight glass bulb is bent into a substantially U-shape at the center between its two ends 9, and the first bent part 10 and both ends 9 are bent. , 9 in a direction substantially orthogonal to the plane including the U-shape to form a pair of second curved portions 11.11, and both end portions 9. , 9 and the first curved portion 10 are positioned adjacent to each other in the same direction, forming a generally saddle shape. This luminous tube 8
A phosphor coating 12 is applied to the inner surface of the mount 13.13, and a flared portion 14.14 of a mount 13.13 is sealed to both ends 9, 9, as shown in FIGS. 3 and 4. has been done. Internal lead wires 1e;, le are sealed in the stem tube 15 connected to the flared portion 14.14, and a filament 17.17 as an electrode is connected between these internal lead wires 16.16. Also each mount 13.1
The thin tubes 18 and 19 led out from the arc tube 18 and 19 are opened at the tip of the stem tube 16 close to the filament 17, and the exhaust inside the arc tube 8 and the inert gas as an ionizable medium are carried out through the thin tubes 18 and 19. will be included.

Incidentally, such a fluorescent lamp is housed in the envelope 4 with both end portions 9°9 and the first curved portion 10 facing the base 2 side, and the filaments 17, 17 are lit. The light tube 6 is of course connected to the cap 2 via a ballast 7.

By the way, a first main amalgam 20 and a second main amalgam 2 are installed in the narrow tubes 18° and 9 at both ends of the arc tube 8, respectively, to control the mercury vapor pressure inside the tube during steady lighting. There is. The first main amalgam 20 on the one ilB tube J8 side is made of indium (In), bismuth (Bi),
It is made of a compound of mercury (Hg) formed into a substantially spherical shape, and is held between the constricted portion 18a provided in the middle of the thin tube 18 and the sealed end so as not to fall off. The melting point of the first main amalgam 20 is lowered by the amount of bismuth (Bi) added, and its operating temperature is the ambient temperature inside the envelope 4 during constant lighting, that is, approximately 70°C to 90°C. ℃, the amount of mercury in the arc tube 8 is controlled to G x 10'' mHg, which maximizes the efficiency of converting it into ultraviolet light.

In addition, the second main Amargano 2I on the other thin tube 19 side is coated with a small amount of nickel or aluminum on the surface of the coil spring or sleeve 22 in order to ensure sufficient contact area with the floating mercury in the arc tube 8. Indium (In) is deposited in a thin film form by plating or vapor deposition, and is inserted and held within the thin tube 19. This second main amalgam 21 does not contain bismuth (Bj) and has a higher melting point than the first main amalgam 2°, and combined with the fact that the surface area is small, mercury is absorbed by fluctuations in ambient temperature. can be released more quickly than the first main amalgam 20.

In this case, instead of the main amalgam 20.21, the amalgam-forming metal and mercury are first placed separately in the capillary tube 18.21.
19 and the arc tube 8, and then the amalgam-forming metal may be amalgamated in the capillary tube 18, 19.

Also, each filament than the main amalgam 20.21)
2y 1 and the second mercury getter 2, located in the vicinity of the hot part 77.17, i.e. in this example between both filaments 17.17 and the open end of the capillary tube 18.19.
2,23 are installed in it. Both mercury getters 22
, 23 has a small amount of indium (In
) is applied in a thin film form by plating or vapor deposition, and one end of this base body 24 is welded to the internal lead embroidery 16. These mercury getters 22 and 23 adsorb the floating water inside the arc tube 8 when the temperature inside the arc tube 8 is low, such as when the lamp is turned off, and conversely, when the lamp is on, the above-mentioned adsorption L
/ H'i dimercury is released into the tube.

Next, a procedure for manufacturing the fluorescent lamp 5 having the above-described structure will be explained.

Yosuii! f+ side mount 13. Stem entry tube 1 of 13
．． The thin tubes 18 and 19 are assembled to 5 and 15, and one of the thin tubes 18 is molded in advance to form a constricted portion 18a in the middle thereof.

Next, once the base bodies 24 and 24 of the mercury getters 22 and 23 are welded to the internal flux glands 16 of one of the mounts 13 and 13, respectively, the base bodies 24 and 24 of the mercury getters 22 and 23 are welded to each other. A second main amalgam 22 in the form of a coil spring or sleeve is inserted through the tube, and the X-tube J9 is sealed and cut.

Next, a mount having a thin tube 18 provided with a constricted portion 18a and a thin W19 into which a second main Amargano tube 22 is inserted.
The flared portions 14 and 14 of the mount having the mounts are each sealed to the openings at both ends of the arc tube 8 before bending, that is, the straight glass bulb. Such maku/to 13. )
If the sealing in step 3 is completed and the ratio is correct, the valve will begin the bending process.
In this step, first, the intermediate first curved portion of the glass bulb along the direction of the chisel is softened by a burner or the like, and then the first curved portion 1o is formed by forming it into a substantially tJ-shape. . Next, both ends 9 of the glass bulb
．． 9 and 1, the part where the second curve is to be formed between the placing part IQ is heated and softened using a burner, and in this state, it is heated and softened in a direction approximately perpendicular to the plane containing the T1 shape (te1 exposed U-shaped A pair of second curved parts 11, 11 are formed by bending the two ends 9.9 and the first curved part 9.9.
A generally saddle-shaped arc tube 8 is formed in which the curved portions 10 are in contact with each other and positioned in the same direction.

Next, the arc tube 8 is evacuated by connecting the thin tube 18 in which the constriction part lea is formed to an exhaust device. Normally, during this evacuation, the arc tube 8 is heated, and the arc tube 8.
Impurities contained in the mount 13° 13, filament 17, 17, etc. are discharged, but in the case of the arc tube 8 of this embodiment, the pulp has already been heated with a burner etc. during the bending process of the glass pulp. Therefore, impurities are discharged at the same time by this heating, and therefore, heating of the arc tube 8 during the evacuation process can be easily completed.

When the evacuation of the arc tube 8 is completed in this way, the spherical first main amalgam 2 is sealed in the capillary tube 18 using this evacuation device, and a predetermined amount of amalgam is passed through the capillary tube 18. An inert gas is sealed inside the arc tube 8.

Finally, the capillary tube 18 was sealed off using a sealing burner built into the exhaust system, thereby installing the main amalgam 20, 21 and mercury getters 22, 23 at both ends of the arc tube 80, respectively. The fluorescent lamp 5 is completed. Note that if an amalgam-forming metal is installed instead of the main amalgam 200, it is of course necessary to seal a predetermined amount of mercury into the arc tube 8 together with an inert gas.

Therefore, in the above-described configuration, the base 2 is inserted into the socket on the power supply side, and the power supply voltage is applied to the arc tube 8.
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The temperature of the first main amalgam 20 that has been installed increases due to the thermal influence of the discharge, and mercury is released into the arc tube 8. The mercury vapor pressure inside the tube after the light output has shifted to a steady state is determined mainly by the temperature of the installation part of the first main amalgam 20, that is, the mercury vapor pressure at which the ultraviolet ray conversion efficiency is the highest. It is controlled to a value around mHg.

On the other hand, when the fluorescent lamp 5 in such an operating state is turned off, the inside of the arc tube 8 and the first. Since the temperature of the installation part of both the second main amalgams 20 and 21 decreases, the suspended mercury in the arc tube 8 is removed from the first amalgam. 2nd both main amalgam; to
, xzFc begins to be adsorbed. In this case, the main amalgam 2
Since the 0.degree. Since the first and second mercury getters 22 and 23 are respectively located near the open ends of the thin tubes 18 and 19 where this mercury vapor collects, a portion of the mercury vapor that flows into the thin tubes 18 and 19 is disposed. is adsorbed almost equally on the indium of both mercury getters 22 and 23. In addition, ndium forms an amalgam by itself, so it has the effect of creating a flow of mercury vapor within the arc tube 8. For this reason, physical adsorption or the like is used as the mercury getter 22.23. The mercury vapor adsorption effect is more pronounced than when a stainless steel wire mesh or the like is used, and therefore, even if the surface area of the mercury getter is small, its mercury content 1 is sufficient.

On the other hand, when the fluorescent lamp 5 is restarted after being extinguished, the mercury getters 22 and 23 that have adsorbed mercury vapor are affected by heat from the adjacent filaments 17 and 17, and ions due to discharge collide with each other. The temperature rises rapidly and a sufficient amount of mercury is quickly released into the arc tube 8.

Therefore, the rise of the light output occurs almost instantaneously, and mercury is emitted almost equally into the arc tube 8 from both ends between the discharge walls, so that ionization also starts from both ends of the arc tube 80, thus causing lighting. The initial brightness along the tube axis direction can be equalized by -1.

In addition, as in the first main amalgam 20 (T), approximately 70°C
Since the mercury vapor pressure inside the tube is controlled to an appropriate value at an operating temperature of ~90°C, the mercury getter 22 is generally released at a slow rate.
,2,? The amount of mercury vapor in the arc tube 8 is substantially insufficient until the first main amalgam 20 starts releasing mercury. There is a risk. However, in the configuration of the embodiment according to the first invention, the second main amalgam 2 on the opposite side
The above-mentioned first main amalgam 2 has a high melting point and a large surface area to reduce the release rate of mercury with temperature fluctuations.
0, this second main amalgam 22 becomes mercury getter 22.0 at the beginning of lighting. Following the tsl, mercury begins to be released into the tube to compensate for the shortage of mercury vapor.

Therefore, during the transition period from the initial stage of lighting to steady lighting, there is little drop in optical output, and good start-up characteristics can be obtained.

In addition, since the second main amalgam 22 contains an extremely small amount of indium, the release of the adsorbed mercury has already been completed by the time the state shifts to the steady lighting state. There is no negative effect on the mercury vapor pressure inside the pipe.

In the above-described embodiment according to the first invention, the compositions of the first and second main amalgams were made different from each other, but depending on the temperature conditions under which the fluorescent lamp 2 is placed, the compositions of the first and second main amalgams may differ.
Both main amalgams may have the same composition, that is, both may have low melting points, or both may have high melting points.

On the other hand, the main amalgam 20 for the fluorescent lamp 5 as described above
．． 21 must be able to control the mercury vapor pressure in the tube to around 6 x 10-"txmHg when the operating temperature is about 70°C to 90°C, but it is difficult to actually control the vapor pressure in the tube under the above temperature conditions. However, the composition is limited to amalgam with a low melting point. Therefore, the main amalgam 20.21
At least one of them needs to have a low melting point.

However, the main amalgam 20 is inside both capillaries 18 and 19.
．． In the case of manufacturing a fluorescent lamp 5 in which a fluorescent lamp 21 is installed, in a typical lamp manufacturing technique, the main amalgam 2 is installed in one thin tube 19, and after 7 hours, the luminous tube 8 is heated to discharge impurities. Since it is necessary to evacuate the inside of the tube and then seal the main amalgam 20 in the remaining capillary tube 18, the main amalgam 2 installed in the capillary tube 19 before evacuation.
1 has a low melting point, problems such as the main amalgam 21 being melted or oxidized due to the heat generated during evacuation will occur.

However, according to the manufacturing method according to the second invention described above, the raw amalgam 21 placed in the thin tube 19 before evacuation has a high melting point composition, and after the evacuation is finished, the main amalgam 20 with a low melting point is placed in the thin tube JB. Since the main amalgam 2θ and 21 are installed in the same place, both main amalgams 2θ and 21 will not be melted or oxidized due to the heat generated during exhaust. At the same time, there is the advantage that conventional lamp manufacturing techniques can be applied as is.

Note that the discharge lamp according to the present invention is not limited to one that is housed in a bulb-shaped envelope and used for lighting. It is also applicable as a light source for dexterity.

〔Effect of the invention〕

According to the first invention detailed above, when restarting the lamp,
The light output rises almost instantaneously, and mercury is emitted almost evenly from both ends of the discharge space within the arc tube, so ionization also starts from both ends, and therefore the tube is Brightness along the axial direction can be made uniform.

Furthermore, according to the second method of the invention, there is no risk that the main amalgam, which has a low melting point, will melt or oxidize due to the heat during exhaust.
Therefore, variations in the action of the main amalgam are reduced, and there is an advantage that the mercury vapor pressure inside the tube can be controlled to a substantially appropriate value.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a sectional view, FIG. 2 is a partially sectional perspective view of a fluorescent lamp, and FIGS.・Earth tube, 9...
Both ends, 13... Mount, 12... Electrode (filament), 18.19... Capillary, ;o, 2... Raw amalgam, 22.23... Mercury getter. Stable agent Patent attorney Takehiko Suzue Figure 1

Claims (2)

[Claims] (1) In a low-pressure mercury vapor discharge lamp in which a mount having electrodes is sealed at both ends of the arc tube and an ionizable medium containing a predetermined amount of mercury and an inert gas is sealed inside the arc tube, both ends of the arc tube are In addition, a main amalgam is placed closer to the end of the electrode to control the mercury vapor pressure inside the tube when the light is on steadily, and a high temperature area near the electrode than both of these main amalgams is equipped with a main amalgam that emits light when the light is turned off. A low-pressure mercury vapor discharge lamp characterized by being equipped with a large number of mercury getters that adsorb floating mercury within the tube and release the adsorbed mercury at startup. (2) The low-pressure mercury vapor discharge lamp according to claim (1), wherein the main amalgams are installed in thin tubes led out from mounts at both ends of the arc tube. 1aI P-generated amalgams have different compositions, and the mercury release rate of the main amalgam on either side is faster than that of the main amalgam on the other side; Low-pressure mercury vapor discharge lamp described in paragraph (2) 0 (4) Main amalgams having different compositions and melting points are installed in the capillary tubes of the mount sealed at both ends of the arc tube, and both main amalgams are This is a method of manufacturing a low-pressure mercury vapor discharge lamp in which a mercury getter is installed in a high-temperature part near the electrode, which adsorbs floating mercury in the tube when the lamp is turned off, and releases the adsorbed mercury when the lamp is started. At both ends, there is a process of sealing mounts with mercury getters installed in advance near the electrodes, and a main amalgam with a high melting point is installed in the capillary of one mount, and after this installation, light is emitted through the capillary of the other mount. A process of evacuating the inside of the tube, and after this evacuation, a process of installing a low-melting-point main amalgam in the capillary of the other mount, and an inert gas and as necessary A method for manufacturing a low-pressure mercury vapor discharge lamp, comprising the step of enclosing mercury according to the method.