JPS6255856A - High pressure metal vapour discharge lamp - Google Patents

Abstract

PURPOSE:To prevent starting characteristic from degradating due to adherence of metal oxide produced on external conductive lead surfaces to the end face of a sealing portion, by spreading a pair of external conductive leads coming outside from the sealing portion at one end of a light emitting tube so that each conductive lead inclines at an angle of 20 degrees or more to the tube axis of the light emitting tube. CONSTITUTION:A pair of external leads 17B, 18 led out from the end face 10Ba of a sealing portion 10B are spreadingly bent at the end face 10Ba to form angles theta1 and theta2, 20 degrees respectively, between the leads and the tube axis, or the A-A line, of a light emitting tube 8. When the leads are connected to an AC power supply, the temperature of external leads 17B, 18 made of molybdenum rise up together with temperature rise of the light emitting tube 8, followed by scattering of molybdenum oxide covering the surfaces. However, the amount of oxide, which adheres to the end face 10B of the sealing portion and potentially forms a short-circuit between the external conductive leads 17B, 18, decreases since the external conductive leads are spread. This results in preventing degradation of starting characteristic of a lamp.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a high pressure metal vapor discharge lamp with a quartz arc tube.

[Technical background of the invention and its problems]

Generally, a high-pressure metal vapor discharge lamp equipped with a quartz arc tube, such as a high-pressure mercury lamp, has an arc tube housed in an outer tube filled with nitrogen gas, and the arc tube heats the end of the arc tube pulp made of quartz glass. A metal foil having a main electrode connected to one end and an external conductor connected to the other end is hermetically sealed to this sealed part.

In addition, an auxiliary electrode is sealed to one of the sealing portions in close proximity to the main electrode via a metal foil.An external conductor is also connected to the other end of the metal foil, and an appropriate amount of wire is connected to the other end of the metal foil. A rare gas for starting, such as argon gas and mercury, is sealed.

By the way, when such a high-pressure mercury lamp is lit for a long time, the starting voltage of the lamp gradually increases.

This may cause the inconvenience of deterioration of starting characteristics.

As a result of diligent investigation into the cause of this problem, the inventors of the present invention found that it is caused by a film made of metal oxide that adheres to the end face of the sealing part from which each external conductor wire connected to the one main electrode and the auxiliary electrode is led out. I found out and did it. That is, the process of forming the 0 arc tube sealing part is as follows.

Each lead-in conductor, consisting of a main electrode, an auxiliary electrode, and an external conductor connected to both ends of a metal foil, is placed inside the end of the quartz glass arc tube pulp, and the end of the pulp is placed while flowing nitrogen gas to prevent oxidation into the pulp. 1.600℃~1,800℃
The pulp is heated to soften it, and then crushed and sealed. At this time, the external conductive wire portion located outside the pulp edge becomes oxidized due to insufficient nitrogen gas atmosphere, causing oxidation of the metal material. For example, when the external conductor is made of molybdenum, molybdenum oxide M005 is generated, and the surface of the outlet path of the external conductor is covered with Mo05. Furthermore, as is well known, arc tubes that have completed the manufacturing process are subjected to aging in order to stabilize their characteristics, and at this time, the external conductor is heated to high temperatures and oxidized. It adds to its richness.

The arc tube formed in this way is housed, for example, in an outer envelope filled with nitrogen gas to create a lamp, but when the lamp is lit, the temperature of the wall of the arc tube reaches several hundred degrees Celsius.
The temperature of the external conductor also rises in the same way, and this heat causes the MoO3 that covers the surface of the lead-out part of the external conductor to scatter, particularly sealing between the external conductors connected to the main electrode and the auxiliary electrode where a potential difference has occurred. This conductive MoO5 layer short-circuits the external conductors, so that even if a voltage is applied between the two external conductors when starting the lamp, there will be no contact between the main electrode and the auxiliary electrode. Since the potential difference is low, glow discharge occurs and the starting characteristics deteriorate.

[Purpose of the invention]

The present invention has been made to address the above drawbacks.

An object of the present invention is to provide a high-pressure metal vapor discharge lamp that can prevent deterioration in starting characteristics due to adhesion of metal oxides on the surface of an external conductor led out from an arc tube sealing part to the end face of the sealing part. do.

[Summary of the invention]

In the present invention, a pair of external conductive wires led out from the sealing portion at one end of the luminous tube are expanded so that each external conductive wire forms an angle of 20" or more with the axis of the luminous tube. This is a characteristic feature.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

Figure 1 shows a 400W high-pressure mercury lamp, in which (1) is an outer tube made of hard glass, and the open end is a stem (2).
, and a cap (3) is attached.

Lead wires (4A) and (4B) are penetrated and sealed in the stem (2), and a support wire (5) is implanted therein.

In addition, one lead wire (4A) and the outer tube of the support wire (5) (
1) A support (6) that also serves as a power supply line is fixedly supported on the inner exposed part, and K is a holder (7).
A).

An arc tube (8) is supported via (7B). The arc tube (8) includes an arc tube pulp (9) made of quartz glass.

The sealing part (IOA) is formed by crushing at both ends (I
OB) is held between the holders (7A) and (7B). For example, metal foil (13A) made of molybdenum is attached to the sealing parts (1oA) and (1oB).
13B) and α-shank are hermetically sealed, and metal foil (13A
), (13B) have main electrodes (15
A), (15B), and an auxiliary electrode Qe for starting is connected to one end of the metal foil α, and.

4 foils for each gold (13A), (13B) ta4
External conductors (17A), (17B) and (18) consisting of a 7" wire are connected.Furthermore, the external conductors (17A) and aυ are connected to the support (6) and The external conducting wire (17B) is connected to a lead wire (4B), and this lead wire (4B) and the other lead wire (4A) that support the support (6) are connected.

It passes through the stem (2), is led out to the outside of the outer tube (1), and is connected to the base (3).

One sealing part (IOB) of the arc tube (8) which is the next important part
This will be explained with reference to FIG.

A pair of external conductors (17B) and αυ led out from the end face (10Ba) of this sealing part (IOB) are bent at the end face (108a) and the tube axis A of the 9 arc tube (8)
- The angles θl and 02 with line A are each 20''.The end face of the sealing part (IQB
a) The distance l between the pair of external conductors (17B) and (181) at K is set to 3fl.

When a lamp with such a configuration is connected to an AC power source via a 400W high-pressure mercury lamp ballast (not shown), each external conductor (17B) made of molybdenum is connected to the arc tube (8). (l@ also rises in temperature and the molybdenum oxide MoO3 covering its surface scatters, but since the external conductors (17B) and (L8) are expanded as described above, the external conductors (17B) and (18) The amount of adhesion on the end face of the sealing part (10Ba), which may short-circuit the lead-out end, is reduced, and most of it is scattered toward the outer tube (1), so even if the main electrode (15B) is turned on for a long time, ) and the auxiliary electrode αe, a glow discharge reliably occurs.

It is possible to prevent deterioration of the starting characteristics of the lamp and maintain stable lighting.

Next, a pair of external guides 1l (17B) and (18) lead out from the one end sealing part (108a) of the arc tube (8).
and the angles θl and θ2 that they form with the arc tube axis A-A line, respectively.
FIG. 3 shows the results of a test to see how the starting voltage Vs changes with the lighting time by making various lamps with various values. In the figure, the vertical axis is the starting voltage Vs.

The horizontal axis shows the lighting time (hours), and for comparison, the conventional lamp shown with K is (θ1 = 02 = 06).In other words, the curve A of the one in which the lead-out portions of the pair of external conductors are parallel is (θ1 = 15°,
θ2 = 0°) 1 Curve B is (θ1 = 02 = 156) 9 Curve C is (θ1 = 15", θ2 = 20") *The curve corresponds to the above example (θ1 = θ2 = 20 @ ) *Curve E is (θ1=02=90°), and the distance l between the pair of external conductors at the end face (108a) of the sealing portion is all set to 3n.

It does not change until the rated life of the time is reached.

In other words, this is considered to be because as θl and θ2 increase, the scattering direction of the oxide generated on the surface of the external conductor changes from the end face of the arc tube sealing portion to the other direction. Also, generally speaking, the center value of the secondary voltage of this type of lamp ballast is 200
Since the permissible power transmission fluctuation range for the power supply voltage is ±6%, the upper limit of the starting voltage is 188V, and considering that starting becomes difficult beyond this value, the lamp life is 12%. It can be seen that in order to facilitate starting over ,000 hours, the curves, that is, both θl and θ2 should be set to 20' or more.

FIG. 4 shows a side view of the sealing portion at one end of the arc tube in another embodiment. In the optical embodiment, as shown in FIG. 2, a pair of external conductors (17
B) and H are bent and expanded so that they are in the same plane as the flattened plane of the sealing part, but in this example, the sealing part (
The difference from the previous embodiment is that each external conductor (17B),
(The end surface of the sealing part (1
It is bent and expanded at 08a). In the case of this embodiment as well, the same effects as in the previous embodiment can be obtained. That is,
A pair of external conductive wires (17B) led out from the sealing part end face (108a).

If the distance between the eels is longer than when they are parallel (in other words, they are spread out), and the angles θ1 and θ2 made with the axes of the nine arc tubes are 20 degrees, in what direction? It may be bent and expanded.

Figure 5 and! FIG. 6 further shows one end side sealing portion of the arc tube in other different embodiments.

As in the previous embodiment, the one shown in FIG.
17B), α is not bent and expanded at the end face of the sealing part (108a), but is bent and expanded at the point where the length Lttm is derived, so that θl and θ2 are 20' or more. It is set. If L is 4 dragons or less, the same effect as in the previous embodiment can be obtained, but if it becomes longer than that, the effect gradually fades.

Furthermore, in each of the above embodiments, the distance l between the pair of external conductors (17B) and the α mark on the end surface of the sealing part (]0Ba) was set to 3 mm, but it is preferable that l be 2 mm or more, and 2 nm or more.
If the length is shorter than 100 kHz, the effect of the present invention will be diminished. l is 2
If there is a possibility that the value is less than 111, connect the external conductor (17B) and mark α to the sealing part (IOB) as shown in Figure 6.
By expanding from the inside, l at the end face (108a) of the sealing portion can be easily set to 2111E or more.

Note that the present invention is not limited to the above embodiments; for example, the material of the external conductor is not limited to molybdenum, but the same effect can be obtained even when other metals such as tungsten are used. It is not a sealed type but a one end sealed type, and can be applied to cases where the external conductors of a pair of main electrodes are led out from this one end sealed part, as well as other high pressure mercury lamps with different inputs. It can also be applied to other high pressure metal vapor discharge lamps such as metal halide lamps.

〔Effect of the invention〕

As detailed above, according to the present invention, even if the conductive metal oxide formed on the surface of the pair of external conductors led out from the end face of the light emitting control stop part is scattered due to the temperature rise when the lamp is turned on, Since the amount of scattering toward the end face of the sealing portion that short-circuits the pair of external conductors can be reduced, it is possible to obtain a lamp that can be started reliably throughout the life of the lamp.

[Brief explanation of drawings]

Fig. 1 is a plan view of a high-pressure mercury lamp which is an embodiment of the present invention, Fig. 2 is a longitudinal sectional view of one end of the arc tube sealed, and Fig. 3 shows that the external conductor of the arc tube is connected to the arc tube. Angle θ with the axis
1. The relationship curve diagram between θ2 and the starting voltage, and FIGS. 4 to 6 are explanatory diagrams of the arc tube sealing portion of other different embodiments, respectively. (1)... Outer tube, (8)... Arc tube. (10A), (IOB)...Sealing part. (10Ba)...End face of sealing part. (13A), (13B), αXun...metal foil. (15A), (15B)... Main electrode. (L6)...Auxiliary electrode. (17A), (17B), bet...external conductor. A-A line... Arc tube axis. θl, θ2...Angle between the external conductor and the luminous tube axis - Engraving of the plane (no change in content) Figure 1 Figure 2 Figure 4 Lighting time (hours) Figure 3 Procedural amendment (method)

Claims (1)

[Claims] A pair of external conductive wires are led out from the sealing part at one end of the arc tube housed in the outer tube, and each external conductor wire is expanded so as to form an angle of 20 degrees or more with the arc tube axis. High pressure metal vapor discharge lamp.