JPS59169049A - Method of producing high pressure sodium lamp of unsaturatedvapor type and structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the manufacture of high pressure sodium lamps of the unsaturated vapor type, and more particularly to a method of loading arc tubes for use in high pressure sodium lamps of the unsaturated vapor type. In the manufacture of sodium lamps, it is customary to provide a tubular ceramic arc tube supported within an evacuated envelope that is secured to a conventional threaded cap member.

Typically, the arc tube is filled with an excess amount of sodium to compensate for sodium losses during lamp operation. Therefore, available high-pressure sodium lamps are mostly of the so-called saturated vapor type, and this saturation is known to cause undesirable fluctuations in lamp voltage and color rendition.

Efforts to eliminate or at least reduce these undesirable effects have led to the conclusion that only lamps in which sodium and mercury are employed in such quantities as to result in total vaporization will yield the desired results. This has been known for a long time.

In other words, as far as efficiency, manufacturing cost, and light output are concerned, a high-pressure sodium lamp in the unsaturated vapor format, in which sodium and mercury are introduced only in amounts such that they are all vapor, is a highly desirable construction.

However, one of the major problems encountered in the manufacture of unsaturated vapor type nonasodium lamps is the introduction of the proper amounts of sodium and mercury.

Since the sodium content is relatively small and sodium is a very chemically active substance, it is very difficult to introduce the correct amount of sodium into the arc tube of an unsaturated steam high-pressure sodium lamp. I found out.

One well-known suggestion for introducing sodium and mercury into the arc tube for high-pressure sodium lamps is to
No. 4,1545 so, issued May 29, 1979 to Fulkbo et al. In this case, sodium azide (NaN3) is dissolved in a solution, placed in a container, and the solvent is allowed to evaporate. Also, Al-Z
A mercury dispenser in the form of r-Tl-Hg alloy is placed in the container.

A container is then placed in an exhaust tube secured to the arc tube, and the exhaust tube is closed or pinched off. Secure another exhaust pipe to the other end of the arc tube and to the exhaust system. Heat the exhaust pipe with a container of sodium and water #
1-containing compounds to supply the desired sodium and mercury into the arc tube. Also, the arc tube is evacuated and refilled with starting gas.

Other techniques for loading arc tubes in unsaturated vapor format include:
Some lamps employ sodium-mercury amalgam within the arc tube. Usually the amalgam is in the form of a single pellet and introduced into the arc tube in such a quantity that all the sodium and mercury are vaporized. However, it has been found that such an arc tube loading method still leaves problems to be solved. More specifically, it has been found that the loadings obtained with a single pellet tend to have relatively large deviations from the average value.

In other words, the loading obtained with a single pellet is
It has an undesirably large deviation from the average value, resulting in an undesirably relatively large deviation in lamp voltage.

OBJECTS AND SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved unsaturated type high pressure sodium lamp and method for its manufacture.

A particular object of the invention is to provide a method for manufacturing an arc tube for a high pressure sodium lamp of the unsaturated type.

Another particular object of the invention is to improve the method of loading the arc tube in a high pressure sodium lamp of unsaturated vapor form. An object of the present invention is to provide an improved structure and method for loading an arc tube.

These and other objects and advantages of the present invention provide that, in accordance with one aspect of the present invention, the average dose placed within the arc tube in loading the arc tube supported within the exhaust glass envelope has a standard deviation less than the standard deviation from the average of the doses in the lamp whose dosing is by a single pellet of sodium-mercury, having a sum substantially equal to a given dose of the lamp. This is achieved by a method for manufacturing high-pressure sodium lamps of unsaturated vapor type, which is carried out by selecting amounts of amalgam.

DESCRIPTION OF THE EMBODIMENTS In order that these and other objects and advantages of the invention may be better understood, the invention will now be described in detail with reference to the drawings.

Referring to the drawings, FIG. 1 illustrates an unsaturated vapor high pressure sodium lamp comprising a sealed exhaust glass tube 5 shaped to fit into a conventional threaded cap member 7. A glass stem member 9 is sealed into the envelope 5 and projects into the envelope. Electrical conductors 11 and 13 are enclosed within and extend through the stem member 9 to provide an electrical connection from the interior of the glass envelope 5 to the exterior.

A conductive support member 15 is fixed to one of the conductors 11, and a pair of crossbars 17 and 19 are fixed to the support member at both ends.A plurality of spring-like members 21 are also fixed to the support member. 15, and the glass envelope 5
It is shaped so that it comes into contact with. Additionally, a pair of getters 23 and 25 are attached to support member 15 and serve to ensure the integrity of exhaust envelope 5.

An arc tube 27 is disposed within the glass envelope 5 and supported by crossbars 17 and 19. The arc tube is preferably made of a material such as polycrystalline alumina and is provided with electrodes 29 and 31 at each end thereof.

One pole 29 is fixedly supported by the cross spar 17, and the other electrode 31 is insulatively supported by the other cross spar 19, but is electrically connected to the conductor 13 passing through the stem member 9. ing. electrodes 29 and 3
A thermal protection member 33 is placed around both ends of the arc tube near 1.
can be wound to reduce the heat difference from the center of the arc tube 27.

Regarding the manufacture of the arc tube 27 of the unsaturated vapor type high pressure sodium lamp described above, doses of sodium and mercury are selected such that they are completely vaporized to provide the desired unsaturated conditions.

In practice, multiple quantities of sodium-mercury amalgam are selected in amounts that provide the desired and required amounts of sodium and mercury for the lamp. These multiple doses of amalgam are introduced into the arc tube 27 resulting in an average dose that has a smaller deviation from the average than the deviation of the dose of a lamp dispensed in a single dose. Roughly speaking, this scaled ramp dose deviation is substantially equal to the standard deviation of a single dose divided by the square root of the number of doses taken.

In other words, x = s/-7- where x = standard deviation of the dose of the lamp employing ll number of doses - standard deviation of the dose of the lamp employing a single dose n = the dose adopted With reference to the comparison diagram in FIG. 2, let us assume that the desired predetermined dosing tooth for a high-pressure sodium lamp in the unsaturated vapor format is a sodium-mercury amalgam with about 14% sodium by weight. .

When the required predetermined dose is given by a single 3-inch pellet, the standard deviation of the resulting material is approximately α61I
9 (curve A). However, selecting multiple portions (3 in this example), each with a gravimetric tOQ and a standard deviation of approximately α6k) to provide the desired predetermined dose;
Loading the lamp with 3 m9 of pellets results in a dose with a standard deviation smaller than the standard deviation of the dose teeth obtained. In other words, 1 Akebono 4i Kirei each 19/3
When determining the dosage of 51 nl from 2 pellets, approximately 0
．． A dosing tooth with a deviation of S5 da is obtained (curve B).

In this way, the dose remains unchanged, but its deviation from the average is improved by using multiple doses with the sum of the agitation doses equal to the Shintaku dose.

Preferably, the quantity is selected from a sodium-mercury amalgam comprising pellets having a weight in the range of about 0.05 to 20.0. It should also be noted that pellets of smaller size than the weight or powder materials described above tend to absorb moisture undesirably. Moisture is detrimental to the resulting lamp structure. On the other hand, pellets larger than the above range severely limit the number of pellets suitable for unsaturated high pressure sodium lamps and also severely limit the reduction of the deviation of the lamp dose from the average.

As a specific example, a 400 W unsaturated vapor type high pressure lamp was manufactured with an arc tube having a volume of about 4.3 cm. Approximately 0.62
Contained three pellets of Tn9. In addition, the arc tube
Quinanone in an amount of approximately 15 torr was supplied, sealed, and placed in an evacuated envelope to provide a high pressure sodium lamp in unsaturated vapor format.

These lamps exhibited a reduction in lamp voltage range from greater than about 30 volts for single pellet dosed lamps to less than about 8 volts for lamps loaded with multiple pellets.

The present invention has been described above with reference to preferred specific examples, but
It is obvious that those skilled in the art can make various changes and modifications without departing from the technical idea of the present invention.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a preferred type of unsaturated vapor type high-pressure sodium lamp of the present invention, and FIG. 2 is a comparative diagram showing the variation in the deviation from the average dose given by employing a plurality of doses. be. 5: Sealed exhaust glass tube 7: Base member 9 Glass stem member 11.1B + conductor 15 - conductive support 17.15M 4 spurs 21: Spring-like member 23.25 Nigeta 27: Arc tube 29.31: Electrode

Claims (1)

[Scope of Claims] (1) A method for manufacturing an unsaturated vapor type high-pressure sodium lamp comprising an arc tube disposed within an exhaust glass envelope and requiring a predetermined amount of amalgam inside, comprising: selecting a plurality of doses from a group of amalgam pellets in sufficient quantity to deliver a quantity of amalgam, and placing the plurality of quantities of amalgam within the arc tube to deliver the predetermined dose; A method of manufacturing an unsaturated vapor type high pressure sodium lamp, characterized in that the average dose of the lamp is made to have a standard deviation smaller than the standard deviation of lamps dosed in a single pellet. (2) If the deviation of the dose in the arc tube is the standard deviation of a single pellet quantity divided by the square root of the number of doses! A method for manufacturing a lamp according to the equivalent claim 1. (3) A method for manufacturing a lamp according to claim 1, wherein the amalgam is in the form of sodium-mercury pellets. 4. The method of claim 1, wherein each of the II 1 ljU quantities of amalgam has a weight in the range of about 0.05 to 2α0In9. (5) In a method of loading an arc tube for an unsaturated vapor type high pressure sodium lamp, selecting a plurality of amalgam pellets having a stacking deviation from the average value in sufficient quantity to provide the required predetermined dose. depositing said plurality of amalgam pellets within said arc tube to provide said required predetermined dose, said dose being obtained by a single aliquot of amalgam pellets; A method of loading an arc tube, characterized in that the amount has a deviation from the average value that is less than the standard deviation of the amount. (6) a patent in which said deviation C1) of said lamp dose is substantially equal to said standard deviation (-) of said single dose amalgam divided by the square root of the number of single doses (n); The arc tube loading method according to claim 5. ()) The amalgam pellet is about Q, 05~20.0
9. The arc tube loading method according to claim 5, wherein the arc tube loading method is within the scope of claim 9. (8) the standard from the average in which the dosage of a plurality of amalgam pellets with a sum equal to a given dosage value is less than the deviation of a ramp with said given dosage value in the form of a single amalgam pellet; An unsaturated vapor type high-pressure sodium lamp with an arc tube arranged in an exhaust envelope, characterized in that it has a deviation. (9) Each of the quantities of the number of flights is approximately r1.05 to 2α0!
9. The high-pressure sodium lamp according to item 8, wherein the desired range is na. al A high pressure sodium lamp in which the dose of the lamp has a deviation from the average value that is less than a single dose deviation.