JPH05275063A - Low pressure mercury vapor discharge lamp - Google Patents

Abstract

PURPOSE:To provide a low pressure mercury vapor discharge lamp, which does not need special member for supporting amalgam, and of which the height of an electrode can be reduced. CONSTITUTION:For a mercury vapor discharge lamp in which a pair of lead wires 4 is led through the end part of an arc tube bulb 1, while the middle part of the lead wires 4 situated in the bulb is supported by a glass bead 6, and in which an electrode 5 is provided on the end part, an amalgam forming metal 7 is mounted on the outer surface of the glass bead 6. Since the amalgam forming metal is mounted on the insulating glass bead 6, by which the lead wires 4 are supported, dispersion of the amalgam due to electron shock is mitigated, while the amalgam is prevented from adhering to the wall of the bulb, and a special amalgam supporting member is not required. Since the size of a mount can be reduced, the height of an electrode can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support structure for a low pressure mercury vapor discharge lamp in which an amalgam is enclosed in an arc tube.

[0002]

2. Description of the Related Art Fluorescent lamps, which are known as representatives of low-pressure mercury vapor discharge lamps, generally have a high wall power, a small bulb diameter, and an envelope. The load becomes high, heat radiation becomes insufficient,
The temperature of the valve rises. For this reason, when pure water silver is used as a mercury vapor supply source as in the prior art, the mercury vapor pressure in the bulb exceeds an optimum value, which causes a problem such as a decrease in luminous flux.

Therefore, when a fluorescent lamp is turned on under severe temperature conditions as described above, it is known that mercury vapor pressure is controlled within an appropriate range by using amalgam instead of pure water silver. There is.

However, the method of controlling the mercury vapor pressure by the amalgam utilizes the characteristic that the vapor pressure of the amalgam is lower than the vapor pressure of pure water silver. In a situation where the temperature of the amalgam is low and the temperature of the amalgam itself is low, the temperature of the amalgam does not reach the temperature most suitable for its operation quickly, and the rate of releasing mercury becomes slow. As a result, the rising characteristics of the luminous flux are inferior, it takes time to reach a stable state, and the startability is inferior.

From the above, the Japanese Patent Application No. 59-
As described in No. 73973, in addition to the main amalgam that controls the mercury vapor pressure during steady lighting, it also adsorbs floating mercury in the tube when the lamp is off and releases the adsorbed mercury during the initial lighting including the start It has been proposed to use amalgams of.

In the above proposal, flare stems are attached to the respective ends of the arc tube bulb having a phosphor coating formed on the inner surface thereof, electrodes are attached to these flare stems, and a thin tube is projected onto the flare stem. The main amalgam is housed in this thin tube, and the starting amalgam is attached to one of the lead wires.

The starting amalgam mentioned above is formed by welding an amalgam supporting piece made of a normal metal such as stainless steel or nickel or a high melting point metal such as molybdenum, tantalum or niobium to a lead wire to form one side surface of the supporting piece. Alternatively, a structure in which an amalgam forming metal made of indium In is attached to both surfaces by means such as plating or vapor deposition is adopted.

In such a structure, when the lamp is turned off, the mercury in the discharge space gathers in the starting amalgam and is captured by the starting amalgam. When the lamp is next started, it receives the heat from the electrodes and receives the heat. The mercury captured by the starting amalgam is instantly vaporized and quickly diffused into the discharge space to make up for the shortage of the amalgam immediately after lighting, thus promoting the evaporation of mercury and increasing the vapor pressure, so that the luminous flux rises faster.

[0009]

However, in the case of such a conventional structure, the supporting piece of the starting amalgam is attached to the lead wire connected to the power source, and therefore the supporting piece of the amalgam is turned on during lighting. In response to electron impact instead of filament, amalgam forming metal such as indium scatters from the amalgam support piece and adheres to the valve wall,
The tube wall may be blackened or the rising of the luminous flux may be deteriorated.

In order to prevent this, it is desirable that the supporting piece of the starting amalgam is supported on the stem while being electrically insulated from the lead wire, but if a special starting amalgam supporting piece is attached to the stem. However, there is a disadvantage that the mount cannot be stored in a small space of the electrode mount and the mount becomes large.

From the viewpoint of increasing the size of the mount, when the electrode height increases due to the increase in size of the mount, the effective light emission length with respect to the entire length of the arc tube becomes shorter, and in particular, the bulb diameter was made smaller and bent. It is not suitable for compact fluorescent lamps that have a discharge path.

From this point of view, when the flare stem is used, the electrode height tends to be relatively high, and the supporting piece of the starting amalgam is attached to the lead wire between the stem tip and the filament. In the structure, the height of the electrode is further increased and the number of parts is increased, which causes problems.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a low-pressure mercury vapor capable of reducing the electrode height without requiring a special member for supporting an amalgam. It is intended to provide a discharge lamp.

[0014]

SUMMARY OF THE INVENTION According to the present invention, a pair of lead wires are penetrated through the ends of an arc tube bulb, and midpoints of these lead wires located inside the bulb are supported by glass beads and at the ends. In a mercury vapor discharge lamp having electrodes attached, an amalgam forming metal is attached to the outer surface of the glass bead.

[0015]

According to the present invention, since the amalgam forming metal is attached to the outer surface of the glass bead supporting the pair of lead wires, the glass bead is insulated from the power source, so that the electron impact is prevented and the amalgam forming Scattering is reduced. Further, since no special amalgam support piece is required and the mount having a structure in which the electrodes are supported by the glass beads does not need to use a flare stem, the mount can be downsized and the electrode height can be lowered.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment.

FIG. 2 is a perspective view of the entire bent type fluorescent lamp, and in the figure, reference numeral 1 is an arc tube bulb. This valve 1
Is formed by bending a glass tube into a U shape, and a phosphor coating 2 is formed on the inner surface thereof as shown in FIG. Electrode mounts 3 are sealed at both ends of the bulb 1. The mount 3 will be described later. Such a valve 1 is attached to the base 20. The mouthpiece 20 is constructed by joining a mouthpiece base 21 and a mouthpiece cap 22 each made of a synthetic resin, and mouthpiece pins 23 are projectingly provided on the mouthpiece base 21.

The cap 22 has insertion holes 24, 24.
Both ends of the valve 1 are inserted into these insertion holes 24, 24, and are joined to the cap 22 by an adhesive (not shown) such as silicon filled inside the cap 22. The electrode mount 3 is shown in FIGS. 1 and 3 and will be described.

The electrode mount 3 includes a pair of lead wires 4 and 4.
A coil filament 5 laid between the ends of the lead wires 4 and 4 inside the bulb, and a glass bead 6 that supports a midway portion of the lead wires 4 and 4 inside the bulb. Then, on the outer surface of the glass bead 6, the lead wire 4, which penetrates the glass bead 6,
The starting amalgam 7 is electrically insulated from the No. 4 and is attached. The starting amalgam 7 is, for example, indium I.
The glass bead 6 is made of an amalgam forming metal having a mercury adsorbing action such as n, that is, a mercury getter metal.
It is applied by coating or vapor deposition on the surface of. An emitter (not shown) is applied to the filament 5.

The mount 3 as described above includes the above-mentioned pair of leads.
Wires 4 and 4 are directly sealed to the sealing portion 7 at the end of the valve 1 and supported by the valve 1. That is, the arc tube shown in the present embodiment is sealed by directly reducing the diameter of the bulb end without using a particular flare stem or button stem, and the sealing portion 8 is provided with the above-mentioned pair of lids. -The wires 4 and 4 are hermetically penetrated and sealed.

A thin tube 9 is connected to at least one end of the valve 1, and the thin tube 9 is projected outward so as to be the coldest part of the valve. The thin tube 9 communicates with the discharge space in the bulb 1 through the open end inside.

A main amalgam 10 is housed in the thin tube 9. The main amalgam 10 is formed by adding mercury to indium, bismuth, tin, lead and an alloy in which these metals are appropriately mixed.

The narrow tube 9 is formed with a narrowed portion 11 for preventing the main amalgam 10 from moving and coming out. Since the main amalgam 10 controls the vapor pressure of mercury, it has to be kept at a predetermined temperature, and when it moves in the narrow tube 9, the temperature changes and the vapor pressure fluctuates. For this reason, it is necessary to fix the main amalgam 10 at a predetermined position on the thin tube 9. In the present embodiment, the main amalgam 10 is made into a substantially spherical mass and is housed in the thin tube 9, and the outer end of the thin tube 9 is sealed, and then the intermediate portion is heated from the outside using a heater or the like. By the diaphragm 1
1 is formed. The arc tube shown in FIG. 1 can be manufactured by the method shown in FIG.

That is, FIG. 3A shows the structure of the mount 3, and as described above, the midpoints of the pair of lead wires 4 and 4 are supported by the glass beads 6, and the lead wires 4 and 4 are supported.
A coil filament 5 is installed between the ends of the coil 4. The glass beads 6 are coated with a paste of the auxiliary amalgam forming metal 7 made by mixing indium fine powder with butyl acetate.

Apart from the mount 3 as described above, the valve 1
And a thin tube 9 which also serves as an exhaust pipe is prepared. As shown in FIG. 3 (B), the bulb 1 has an open end, and a phosphor coating 2 is formed on the inner surface of the bulb wall.

The mount 3 is attached to the open end of the valve 1.
Then, the thin tube 9 is inserted, and while maintaining these positions, the end portion of the valve 1 is heated by the gas burner 30. Then, the end portion of the bulb 1 is softened by heating, and the diameter is reduced by this softening.
The diameter reduction phenomenon is a peculiar property of the glass tube, and such a diameter reduction causes a lump of meat, and this flesh of the thin tube 9
Is welded to the outer surface of. Therefore, the end of the valve 1 is shown in FIG.
As shown in (C), the lead wires 4 and 4 are sealed to the sealing portion 8 and the thin tube 9 is joined.

After that, the inside of the valve 1 is evacuated through the thin tube 9 and a rare gas such as argon is sealed therein, and the main amalgam 10 is inserted into the thin tube 9 to seal the outer end of the thin tube 9. .. Then, an intermediate portion of the thin tube 9 is externally heated by a heater to form the narrowed portion 11, thereby completing the arc tube shown in FIG. The operation of the bent type fluorescent lamp thus constructed will be described.

Since the ambient temperature is low when the lamp is off, the mercury in the tube is contained in the starting amalgam 7 attached to the outer surface of the glass bead 6 and the main amalgam housed in the thin tube 9 protruding from one end of the bulb 1. Adsorbed on 10. Therefore, the mercury vapor pressure in the tube is low.

Immediately after the lamp is turned off, the suspended mercury vapor is about to be adsorbed by the main amalgam 10 in the thin tube 9 having a low temperature, but in the process of moving toward the main amalgam 10, the discharge space and the main amalgam 10 are separated from each other. A large amount is adsorbed by the starting amalgam 7 located in the middle of the flow of the mercury vapor during the period.

When the lamp is turned on, the bulb 1
Arc discharge occurs between the filaments 5 and 5 installed at both ends of the. At this time, the starting amalgam 7 attached to the glass beads 6 located relatively close to the filaments 5 and 5 receives the radiant heat from the filament 5 and is heated, so that the mercury adsorbed when the lamp is turned off is released. As a result, mercury vapor is quickly diffused in the discharge path, and the mercury vapor pressure in the discharge path rises quickly.

In this case, the starting amalgam 7 releases a large amount of mercury adsorbed in the initial stage of lighting in a short period of time, and therefore promotes an increase in mercury vapor pressure in the discharge path.
The luminous flux rise time is shortened.

In this way, when the lamp reaches a stable lighting state and the amount of mercury released from the starting amalgam 7 into the discharge space is excessive, the main amalgam 10 contained in the thin tube 9 having a low temperature is excessive. By adsorbing mercury, the mercury vapor pressure in the bulb 1 is controlled to an optimum state.

In the fluorescent lamp of the above-mentioned embodiment having such an action, the starting amalgam 7 is replaced by the glass bead 6.
Since the starting amalgam 7 is insulated from the lead wire 4 by being attached to the amalgam 7,
That is, the proportion of indium scattered is reduced. Therefore, the starting amalgam 7 is prevented from adhering to the valve wall. For this reason, the luminous flux rising performance at the time of starting can be favorably maintained even after the lighting time has elapsed or the number of blinks has increased.

Moreover, the mount 3 having the above structure is originally of the type having the glass beads 6, and since the starting amalgam 7 is applied to such glass beads 6,
No special amalgam support member is required. Therefore, the number of parts is reduced and it is not necessary to provide a special amalgam support member on the mount, so that the mount 3 can be downsized and the electrode height can be reduced.

From the viewpoint of the electrode height, in addition to using no special amalgam support member, the valve sealing structure is a structure in which the valve end is reduced in diameter and directly sealed, and a special flare stem is provided. Since it is not used, it is effective in reducing the electrode height. Therefore, the effective light emission length with respect to the entire bulb length can be increased. In addition,
The present invention is not limited to the above embodiment.

That is, although the U-shaped fluorescent lamp has been described in the above embodiment, the present invention is not limited to the shape of the bulb, and may be a straight tube type, a ring type, a W type, or two U type. The present invention can be implemented with a bulb, a bulb having four or more U-shaped bulbs connected, and a saddle-type fluorescent lamp. Further, the present invention can be practiced with a lamp having no fluorescent coating on the inner surface of the bulb and a lamp having no ultraviolet blocking film on the outer surface.

Further, the present invention may be a lamp of the type in which the amalgam-forming metal is attached to the glass beads 6 without using the main amalgam, and the amalgam also serves as the main amalgam and the starting amalgam. Also, the mount may use a button stem or a bead stem, but a mount using a flare stem is not preferable.

[0038]

As described above, according to the present invention, since the amalgam forming metal is attached to the outer surface of the glass bead,
The amalgam forming metal is electrically insulated, scattering by electron impact is reduced, and it is prevented from adhering to the wall of the bulb, and the rise time of the luminous flux at the time of starting can be shortened for a long period of time. Moreover, since the glass beads that are originally used as the mount members are used as they are as support members for the amalgam forming metal, no special parts are required, the assembly labor is not increased, and the mount structure can be improved. Since the size can be reduced, there is an advantage that the electrode height can be reduced and the effective light emission length can be increased with respect to the entire bulb length.

[Brief description of drawings]

FIG. 1 is a sectional view of an end portion of a fluorescent lamp showing an embodiment of the present invention.

FIG. 2 is a perspective view showing the entire fluorescent lamp of the same embodiment.

3A to 3C are views for explaining the method of manufacturing the fluorescent lamp of the embodiment, in which FIGS.

[Explanation of symbols]

1 ... Arc tube bulb, 2 ... Fluorescent film, 3 ... Mount,
4 ... Lead wire, 5 ... Filament, 6 ... Glass bead,
7 ... Auxiliary amalgam forming metal, 9 ... Capillary tube, 10 ... Main amalgam.

Claims (2)

[Claims] 1. A mercury vapor discharge lamp having a pair of lead wires penetrating the ends of an arc tube bulb, a midway point inside the bulb of these lead wires being supported by a glass bead, and electrodes being attached to the inner ends thereof. A low-pressure mercury vapor discharge lamp having an amalgam forming metal attached to the outer surface of the glass bead. 2. A thin tube which is electrically connected to the inside of the bulb is projected from an end portion of the arc tube bulb, and a main amalgam is accommodated in the thin tube. The amalgam forming metal formed on the outer surface of the glass bead is an auxiliary amalgam. The low-pressure mercury vapor discharge lamp according to claim 1, which is configured.