JPS60208023A - Manufacture of low pressure mercury discharge lamp - Google Patents

Abstract

PURPOSE:To fix amalgam easily and reliably in this tube by encapsulating amalgam in thin tube then heating to fusable state to perform fusable sealing thereafter integrally welding the amalgam to the sealing section under high temperature. CONSTITUTION:Approximately spherical amalgam 19 is sealed in thin tube 18 utilizing an evacuation unit not shown. Then the thin tube 18 is heated in the way to fusable state by means of a burner 23 assembled in said unit thus to form a softening section 24 where fused glass is collected locally. Thereafter, said tube 18 is fusably sealed air-tightly at the portion of softening material 24 by pulling in the longitudinal direction, for example, to form a sealing section 25. After sealing, a light emission tube 8 is inverted vertically to fix the amalgam 19 to the softening section 24 or the sealing section 25 during when said section 24 or 25 is maintained in high temperature condition. In other word, it is positioned at the side of sealing section 25 in thin tube 18.

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 particularly relates to a low-pressure mercury vapor discharge lamp in which the amalgam is fixed in a thin tube at the end of the arc tube. Method for - related.

[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 × 10
■It is designed to maximize the efficiency of converting the supplied electricity into ultraviolet light during lighting, so for example, if this fluorescent lamp is housed in a bulb-shaped envelope and lit,
As the ambient temperature increases, the mercury vapor pressure exceeds the above 1 mK, causing problems such as a decrease in light output.

When using fluorescent lamps under harsh temperature conditions, the mercury vapor pressure inside the fluorescent lamps is controlled within an appropriate range using amalgam, which has a lower vapor pressure than pure water. This method is considered effective.

By the way, conventionally, this type of amalgam is often attached to the stem wall at the end of the lamp, but this amalgam is placed in the facepiece or in a state of coexistence of solid and liquid depending on the temperature of the lamp, and tends to flow out during lighting. The inventors have attempted to encapsulate the amalgam within a capillary that extends from the stem.

However, if the amalgam is not fixed at a fixed position within the capillary after being sealed, the amalgam may move within the capillary and break, for example when the direction in which the rung is lit is changed. In this case, even if the tube is the same, there will be a temperature difference between the sealed end and the end on the discharge space side, so the temperature at the amalgam installation part will also tend to fluctuate depending on the lighting direction, etc., and the vapor pressure will be controlled. There is a possibility that variations in characteristics may occur. Therefore, when enclosing amalgam in a capillary, it is desirable to fix it immovably in a fixed position within the capillary, but in the past, there was no way to easily and reliably fix amalgam inside the capillary. Measures were required.

[Purpose of the invention]

The present invention was made based on these circumstances, and
The object of the present invention is to provide a method for manufacturing a low-pressure mercury vapor discharge lamp that can simply and reliably fix amalgam or amalgam-forming metal in a fixed position within a capillary.

[Summary of the invention]

That is, in order to achieve the above object, the method of the present invention seals amalgam or amalgam-forming metal in a glass capillary, heats the capillary to a melted and softened state, and seals the capillary by cutting it airtight. The present invention is characterized in that the amalgam or amalgam-forming metal is integrally welded to the sealed portion which is in a high temperature state after being fused and sealed.

[Embodiments of the invention]

Below is an example of the present invention. A description will be given based on a drawing in which the method is applied to a spherical lighting device.

First, to explain the structure of this lighting device, 1 in Figure 1.
is a cover made of synthetic resin, and a cap 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 typical of a 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 run f5 has a straight glass bulb bent into a substantially U-shape at the center between its two ends 9, 9, and the first curved part 10 and both ends 9, 9. 9 in a direction substantially perpendicular to the plane containing the U-shape, and the U's are adjacent to each other and positioned in the same direction. A phosphor wave antinode 12 is attached to the inner surface of the arc tube 8, and both ends 9
, 9, the flare portions 14 of the mount 13 are sealed, respectively, as shown in FIG. Internal lead wires 16.degree. 16 are sealed in the stem tube 15 connected to the flared portion 14, and a filament 17 as an electrode is connected between these lead wires 16.degree. Further, the thin tubes 1aa and 18b led out from the stem tube 5 of each mount 13 are connected to the tip Gi+ of the stem tube 15 near the filament 17,
It is opened at the section f, and the arc tube 8 is evacuated and a predetermined amount of inert gas is filled in through the thin tubes 18h and 18b.

In addition, the envelope 4 is placed in such a position that the fluorescent lamp "5", both ends 9.9, and the first curved part 10 are directed toward the base 2.
The filament 17 is housed in the lighting tube 6.
Of course, it is connected to the base 2 via the ballast 7.

Incidentally, an amalgam 19 is installed within the arc tube 18b on one end side of the arc tube 8 to control the water@vapor pressure within the tube during steady lighting. Here, one of the thin tubes 18
A threaded portion 20 is provided in the middle of #llI tube 18b to prevent the amalgam 19 from falling into the arc tube 8 when the henoamalgam 19 is sealed in the tube 18b. Since no amalgam is sealed, the diameter-reduced portion as described above is not provided and is straight. Note that instead of the amalgam 19, the amalgam-forming metal and mercury may first be separately sealed in the capillary tube Jab and the arc tube 8, and then the amalgam-forming metal may be amalgamated in the capillary tube 18b. .

In this example, the amalgam 19 is indium (I).
n), bismuth (1111), tin (Sn), lead (pb
) is formed into a substantially spherical shape by adding mercury (Hg) 1 to an alloy of various metals such as ), and is integrally melted into the sealing part 25 of the one thin fl 18b so as not to be movable. The operating temperature of this amalgam 19 is the ambient temperature inside the envelope 4 during steady lighting, that is, approximately 70°C to 9.0°C.
When the amount of mercury in the arc tube 8 is reached, the amount of mercury in the arc tube 8 is controlled to be around 6 x 10 mHg, where the efficiency of converting into ultraviolet light is the highest.

In the fluorescent lamp 5 of this embodiment, the amalgam 1
A mercury getter 21 is installed at a warmer portion closer to the filament 17 than the mercury getter 9, that is, located between the filament 17 and the open end of the thin tube Jab. Mercury and Ta2 are stainless steel, nickel, molybdenum wire mesh or Ir.
1. A small amount of indium (In 2 ) is deposited on the surface of a base 22 made of f-rate material by plating or vapor deposition, and one end of this base 22 is welded to the internal lead wire 16 . The mercury getter 2 adsorbs floating mercury 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 releases the adsorbed mercury into the arc tube 8 when the lamp is turned on. ing.

In a lighting device with such a configuration, the base 2 is inserted into the socket on the power supply side, and the power supply voltage is set to ? I- When the voltage is applied to the arc tube 8 and started, the amalgam 19 is heated by the discharge! The temperature rises in response to #, and mercury is released into the arc tube 8. As the temperature of the wall of the arc tube 8 and the capillary tube 18b rises due to this discharge, the temperature of the amalgam 19 inside the capillary tube Jab gradually rises, and an amount of mercury commensurate with this temperature rise is released into the arc tube 8.
released within. After startup, when the light output reaches its peak value and reaches a steady state, all of the mercury in the amalgam J9 evaporates, and the mercury vapor pressure inside the tube from this point on is the vapor pressure determined by the temperature of the part where the amalgam 19 is installed, that is, the ultraviolet rays. The conversion efficiency is controlled to a value around 6×10 Hg, which is the highest.

On the other hand, when the fluorescent lamp 5 in such an operating state is turned off, the floating mercury in the arc tube 8 begins to be adsorbed by the amalgam 19 as the temperature decreases. At this time, amalgam 1
Since the mercury 9 is housed in the capillary tube 18b, the floating mercury in the arc tube 8 flows toward the open end of the capillary tube 18b.

The mercury getter 2 is located near the open end of the thin tube 111b where this floating mercury collects, and the vapor pressure of indium-mercury when the light is off is lower than the vapor pressure of the amalgam 19. Most of the floating mercury is adsorbed by the indium of this mercury getter 21.

Therefore, when the fluorescent rung 5 is restarted, the mercury getter 21 that has adsorbed mercury is not affected by radiant heat from the filament 17, but receives ion bombardment from the discharge, so the temperature rises rapidly 7 and a sufficient amount of mercury is absorbed. The light is immediately emitted within 8. As a result, the rise 9 of the optical output occurs almost instantaneously, and the rise characteristics can be greatly improved.

Next, the manufacturing procedure of the fluorescent lamp 5 in which the mercury vapor pressure inside the tube is controlled by the amalgam 19 as described above will be explained with reference to FIGS. 4 to 6.

First, as shown in FIG. 4, at the l1II+ end opening of the arc tube 8 before bending, that is, the straight glass bulb,
The flare portion 14 of the mount 13, on which the filament 17 and 18% of the thin tubes have been assembled, is sealed. In addition, the fourth
The figure shows an opening at one end in which the amalgam 19 is enclosed, a capillary tube 18b having a reduced diameter hB 2 (7), and a filament 17
etc. are illustrated.

Subsequently, the bulb bending step begins, and in this step, the first bending portion at the longitudinally intermediate portion of the glass bulb is heated and softened using a burner or the like, and in this state, the first bending portion is bent into a substantially U-shape. 1. A curve forming section 10 is formed. Next, the second curved portion between the end portions 9, 9 of the glass pulp and the first curved portion 10 is similarly heated and softened, and in this state, the above-mentioned U
A pair of second curved portions 11.11 are formed by bending into a substantially U-shape in a direction substantially perpendicular to a plane including the shape. By bending twice in this manner, a generally saddle-shaped arc tube 8 is formed.

Next, thin tubes 18a are led out from both ends of the arc tube 8.

Among the tubes 18b, one tube 1 is not filled with amalgam.
The interior of the arc tube 8 is evacuated by preliminarily sealing or chipping the arc tube 8&, and connecting the other capillary tube 18b to an exhaust device. During this evacuation, the entire arc tube 8 is heated, and the arc tube 8. Impurities contained in the mount 13, filament 17, etc. are discharged. In addition, when exhausting the inside of the arc tube 8, use not only one side exhaust scale but also both fine %j8h, 18b.
It is also possible to use exhaust on both sides.

After the evacuation of the arc tube 8 is completed in this way, the arc tube 8 is
A predetermined amount of inert gas is sealed inside the chamber, and a substantially spherical amalgam 19 is sealed using the exhaust device as shown in FIG. At this time, the amalgam 19 is
It will not get caught in the reduced diameter portion 20 of b and fall into the arc tube 8.

Next, as shown in FIG. 6, the burners 23, 23 built into the exhaust system are used to heat the middle of the thin tube 18 to a melting and softening state, so that the molten glass is locally collected. A softened portion 24 is formed. Subsequently, for example, by pulling the capillary tube 18 in the axial direction, the capillary tube 8 is hermetically sealed at the melted and softened portion 24, and the sealing portion 25 is sealed.
form. After sealing, the arc tube 8 is turned upside down while the melting and softening part 24 or the sealing part 25 is still in a high temperature state and the amalgam 19 is transferred to the melting and softening part 2.
4 or the sealing part 25. That is, this thin tube 18
It is positioned and fixed immovably to the sealing part 25 side inside.

If an amalgam-forming metal is used instead of the amalgam 190, the amalgam-forming metal is welded to the sealing part 25 in the capillary tube 18b in the same manner as the amalgam 190, and then the arc tube 8 is inserted through the capillary tube 18m on the opposite side. A predetermined amount of mercury is sealed inside.

According to such a manufacturing method, the amalgam 19 is formed into a thin tube 1.
After sealing and cutting the amalgam 19, the amalgam 19 is integrally welded into the molten glass, so that the amalgam 19 can be immovably fixed at a fixed position within the capillary tube 18 at the same time as the capillary tube 18 is sealed. The work of fixing the amalgam 19 can be easily and reliably performed.

Moreover, in the case of the above embodiment, since the amalgam 19 itself was sealed in the thin tube 18b, this 7-r! Mu19
is heated by contact with glass in a high temperature state, and mercury is released into the arc tube 8, and in the case of this embodiment, the mercury getter 21 is located near the opening of the capillary tube 18. As mentioned above, the mercury released into the tube is adsorbed by the mercury duck 21 as the temperature decreases. Therefore, even when the mercury getter 21 is lit for the first time, mercury is already adsorbed, so that the rise 9 of the optical output when the light is lit for the first time is faster, and there is an advantage that the rise characteristics can be improved. .

In the above-described embodiment, a mercury getter was installed in the high temperature part near the electrode, but the mercury duck may be omitted depending on the case.

Furthermore, the low-pressure mercury vapor 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 can be similarly applied as a light source for a copier that lights up by being exposed to the light, or as a light source for a copying machine that flashes many times.

〔Effect of the invention〕

According to the method of the present invention described in detail above, the amalgam or amalgam-forming metal can be immovably fixed in a fixed position within the capillary at the same time as the capillary is sealed, and therefore the amalgam or amalgam-forming metal can be fixed in place. can be done easily and reliably.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a cross-sectional view of a lighting device, FIG. 2 is a partially cross-sectional perspective view of a fluorescent lamp, FIG. 3 is a cross-sectional view of a tube end, and FIG. 4 is a cross-sectional view of a lighting device. 6 through 6 are cross-sectional views showing the manufacturing process in order. 8... Arc tube, 18... Thin tube, 19... Amalgam, 24... Melting and softening part. Applicant's agent Patent attorney Takehiko Suzue No. 60

Claims (1)

[Claims] In a method for manufacturing a low-pressure mercury vapor discharge lamp in which the mercury vapor pressure in a glass arc tube is controlled by an amalgam installed in a thin tube at the end of the arc tube, the amalgam or mercury in the tube is controlled in the thin tube. A step of inserting an amalgam-forming metal that forms an amalgam by bonding with the tube, a step of heating the above-mentioned capillary to a melted and softened state and sealing the melted and softened portion by melting, and a step of sealing the melted and softened portion after the melting and sealing. A method for manufacturing a low-pressure mercury vapor discharge lamp, comprising the step of integrally welding the amalgam or amalgam-forming metal to a sealing portion that is in a high temperature state.