JPS59169036A - Method of producing light emitting tube of unsaturated vaporhigh pressure sodium lamp - Google Patents

Abstract

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

Description

Description: TECHNICAL FIELD This invention relates to high pressure IJ lamps of the unsaturated vapor type, and more particularly to a method for manufacturing arc tubes for unsaturated vapor high pressure sodium lamps.

BACKGROUND OF THE INVENTION In the art of high pressure sodium lamps, the most well-known configuration includes a tubular ceramic arc tube within an evacuated glass envelope. The arc tube is filled with noble gases and excess amounts of sodium and mercury.

In other words, the arc tube has a saturated sodium filling due to the well-known tendency for large amounts of sodium to be lost during lamp operation. Moreover, such saturated type high pressure sodium lamps are in high demand due to the undesirable changes in color rendering and operating voltage that they occur.

In order to eliminate or at least reduce the undesirable properties mentioned above, high pressure sodium lamps of the so-called unsaturated vapor type have been developed. The construction of this lamp is somewhat similar to the saturated type of lamp, except that the amount of sodium hydroxide is greatly reduced. Moreover, such a reduction in the sodium content is possible as long as provision is made to absorb excess oxygen undesirably associated with the filling or noble gas enclosed in the arc tube. I know.

One technique for accomplishing this unwanted absorption of oxygen within the arc tube is to encapsulate an oxygen absorbing getter within the arc tube along with conventional amounts of sodium, mercury, and rare gases. One such arrangement is described in commonly assigned US patent application Ser. No. 473,895, filed on the same date as the present application.

In this application, a getter material is placed within the arc tube and in contact with the gas within the arc tube.

Thus, the unwanted oxygen in the arc tube produced during the sodium or mercury evaporation process or accompanying the admitted noble gases is absorbed by this getter material and the reformation of the compound is prevented.

It has been found, however, that although the above-described technology represents a significant improvement over the construction of previously known unsaturated vapor high pressure sodium lamps, some deficiencies remain. Specifically, the direct contact between the encapsulated getter material and the hottest part of the tubular ceramic envelope of the arc tube causes what is believed to be a chemical reaction between them, resulting in undesirable darkened areas in the ceramic envelope. It was found that there is a tendency to cause As is clear, darkening of the arc tube is not a desirable condition.

It is an object of the present invention to provide an improved unsaturated vapor type high pressure sodium lamp. Another object of the invention is to enhance unsaturated vapor high pressure sodium lamps by improving the arc tube. Another object of the present invention is to provide an improved method for manufacturing arc tubes used in IJ umlumbs (unsaturated vapor type high pressure). Another object of the invention is to provide a method for manufacturing arc tubes for unsaturated vapor type high pressure sodium lamps in which undesirable vessel discoloration is prevented.

In accordance with one aspect of the present invention, these and other objects, advantages and capabilities are achieved by providing an oxygen absorbing getter attached to one of a pair of electrodes and a tubular ceramic container filled with a quantity of mercury, sodium and a noble gas. is achieved by a method for manufacturing an arc tube for an unsaturated vapor type high pressure sodium lamp, wherein the electrodes are each sealed at the ends of the tubular ceramic vessel and the getter is spaced within the vessel.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the present invention, as well as other objects, advantages and capabilities thereof, may be fully understood, reference will now be made in detail to the preferred embodiments of the present invention, with reference to the accompanying drawings.

Referring to the accompanying drawings, FIG. 1 shows an unsaturated steam high pressure vessel with a hermetically sealed and evacuated glass vessel 5.
An IJum lamp is exemplified.

The glass container 5 is configured to fit into a conventional screw-type base member 7. Glass stem member 9
is sealed in the container 5 and protrudes into the container 5. Electric conductors 11 and 13 each pass through the stem member 9 in a sealed state to establish an electrical connection between the inside and outside of the glass container 5.

A conductive support member 15 is attached to one of the electrical conductors 11 and a pair of crossbars 17 and 19 are attached to opposite ends of the support member 15. Additionally, a plurality of spring-like members 21 are attached to the support member 15 and are configured to come into contact with the glass container 5 .

Furthermore, a pair of getters 23 and 25 are attached to the support member 15 and serve to ensure the integrity of the evacuated container 5.

The arc tube 27 is placed within the glass container 5 and supported by the crossbars 17 and 19. The arc tube 27, which is preferably made of a material such as polycrystalline alumina, includes electrodes 29 and 31 at each end thereof. One electrode 29 is attached to and supported by the cross spar 17, and the other electrode 31 is insulated and supported by the other cross spar 19, and is electrically connected to the electrical conductor 13 passing through the stem member 9. There is. A heat storage element 3 is placed around the electrodes 29 and 31 at both ends of the arc tube 27.
3 may be wrapped around the arc tube 27 to reduce the temperature difference with the center of the arc tube 27.

Referring to FIG. 2, the arrangement of an oxygen absorbing getter 37 is shown, which getter 37 may be in the form of a support member or substrate 49 to which an oxygen absorbing metal alloy 51 is deposited, for example by sintering. It should be noted that preferred. Preferably, the substrate 49 is comprised of a material such as nickel-plated iron and the getter material to be sintered is zirconium, aluminum, titanium, scandium,
It is an alloy of metals selected from the group consisting of cerium, lanthanum, thorium, or yttrium.

However, oxides of other rare earth elements are also suitable getter agents for depositing on substrate 49.

In the process of manufacturing the above-mentioned arc tube 27 in FIG.
An oxygen absorbing getter agent or metal alloy 51 is sintered to a substrate 49, preferably in the form of a perforated disk with slits, to form the getter 37. This getter 37 is preferably formed to be attached to the shank portion 43 of the electrode member 39, for example by sliding a perforated disk (49) with a slit onto the shank portion 43.

In assembling the arc tube, one electrode 31 is connected to the arc tube 27.
sealed at one end of a ceramic container.

Subsequently, aliquots of sodium, mercury and noble gas are inserted into the ceramic vessel of the arc tube 27.

This quantity contains an amount of sodium and mercury that will completely evaporate to provide the desired unsaturated vapor type high pressure sodium lamp. Preferably, a sodium-mercury amalgam that decomposes within the arc tube 27 is deposited within the arc tube and a noble gas is admitted to one end of the arc tube 27.

Thereafter, the other electrode 29 in FIG. 1 to which the oxygen absorbing getter 37 is attached is sealed to the other end of the arc tube 27. Note that electrodes 2 are provided at both ends of the tubular ceramic container of the arc tube 27.
To seal 9 and 31, it is preferred, although not necessary, to use a 7-lit sealing technique. A ceramic wafer 41 of FIG. 2 is attached to an electrode member 59, and a glass 7 piece material, preferably in the form of a wafer with a central hole (not shown), is placed within the arc tube 27 to provide the cathode portion 45 and getter 37. This state is used to seal the electrodes 29 and 31 with a desired frit at the end of the arc tube 27.

Referring to the flowchart of FIG. 3, the method for manufacturing an arc tube of the present invention can be easily understood. This method first seals one electrode to one end of the tubular ceramic container of the arc tube. Next, sodium, mercury, and a noble gas are introduced into the vessel in amounts sufficient for evaporation and to provide an unsaturated vapor type high pressure sodium lamp. Thereafter, an electrode with an oxygen absorbing getter agent attached thereto is sealed to the other end of the tubular ceramic vessel to provide the desired arc tube.

A method has thus been provided for manufacturing arc tubes for unsaturated vapor type high pressure sodium lamps.

Although one technique for mounting the getter within a container and spaced from the container has been disclosed, it will be appreciated that other methods of mounting the getter may be used. For example, the getter may be welded to the cathode shank or applied or attached to the cathode portion 45 of the electrode.

In either case, the getter is spaced from the ceramic envelope of the arc tube.

Although what is presently considered to be the preferred embodiment of the invention has been illustrated and described, various modifications and changes may be made thereto without departing from the invention as defined by the claims. should be obvious to engineers in this field.

[Brief explanation of drawings]

Fig. 1 is an elevational view showing a preferred type of unsaturated vapor type high-pressure sodium lamp to which the present invention is applied, and Fig. 2 is an enlarged perspective view showing the arrangement of electrodes with oxygen-absorbing getters attached inside the arc tube. , FIG. 3 is a diagram 74-4 illustrating the process of manufacturing one embodiment of the arc tube of the high-pressure sodium lamp of FIG. 1.
It's chard. 5 Nigarasu container 7: Pace member 9 Nigarasu stem member 11.15: Electric conductor 15: Conductive support member 17.19: Ripper spar 21 = Spring-like member 23.25 Nigeta 27: Arc tube 29.31: Electrode 37: Oxygen absorption getter 39: Electrode member 41: Ceramic wafer 43: Shank portion 45: Cathode portion 49: Substrate 51: Oxygen absorption metal alloy JP-A-59-IG903G (5) FIG. 2

Claims (11)

[Claims] (1) attaching an oxygen-absorbing getter to at least one of a pair of electrodes; sealing one of the pair of electrodes to one end of a tubular ceramic container; and supplying a certain amount of mercury, sodium, and a rare gas to the and sealing the other of the pair of electrodes with a getter attached to the other end of the tubular ceramic container to form an arc tube for an unsaturated vapor type high pressure sodium lamp. A method for manufacturing an arc tube for an unsaturated vapor type high-pressure sodium lamp, characterized in that: (2) The step of inserting the mercury, sodium and noble gas into the container comprises inserting a sodium-mercury amalgam into the container.
Manufacturing method described in section. 3. The method of claim 1, wherein the oxygen-absorbing getter is in the form of sintered metal adhered to a substrate, and wherein the getter is adjacent to at least one of the electrodes. (4) Form the oxygen absorbing getter by sintering metal on a perforated disc support, split the disc support, and use the split disc support as the electrode. 2. The manufacturing method according to claim 1, further comprising the step of attaching the disk support so that the disk passes through the disk support. (5) the getter is aluminum, zirconium,
A method according to claim 1, in the form of a metal alloy selected from the group consisting of titanium, scandium, hafnium, cerium, lanthanum, thorium and yttrium. (6) The manufacturing method according to claim 1, wherein the oxygen absorbing getter is spaced within the tubular ceramic container and is in VIS contact with at least one of the electrodes. (7) the oxygen-absorbing getter is in the form of a zirconium-aluminum alloy sintered to a perforated and split nickel-plated iron substrate; The manufacturing method according to claim 1, wherein the manufacturing method is attached to. (8) sealing a first electrode to one end of a tubular ceramic container; inserting a sodium-mercury amalgam and a rare gas into the tubular ceramic container; and attaching an oxygen-absorbing getter to the second electrode. and sealing the second electrode with an attached getter to the other end of the tubular ceramic vessel to provide an arc tube for a high pressure sodium lamp in the unsaturated vapor format. A method for manufacturing an arc tube for an unsaturated vapor type high-pressure sodium lamp. 9. A method according to claim 8, wherein the oxygen absorbing getter is in the form of a perforated and split support disk of sintered oxygen absorbing material. (10) The manufacturing method according to claim 8, wherein the step of attaching the oxygen-absorbing getter to the second electrode includes the step of separating the getter from the tubular ceramic container. (11)-, 'A patent comprising the step of sintering a metal alloy selected from the group consisting of hafnium, aluminum, titanium, scandium, hafnium, cerium, lanthanum, thorium, and yttrium onto a substrate and attaching the substrate to the electrode. The manufacturing method according to claim 8.