JPS6145554A - High brightness discharge lamp - Google Patents

Abstract

PURPOSE:To obtain a captioned lamp with no decrease in a luminous flux while having an improved light distribution property by providing a getter holding material inside an outer tube so as to surround the luminous tube end part far from the sealing part of the outer tube and a getter coating on the inside surface of the outer tube. CONSTITUTION:A ring-shaped getter holding material 13 is provided on the luminous tube end part far from the sealing part of an outer tube 9, namely on the periphery of the tube end part, where an electrode conductor 2 is sealed in, so as to surround the tube end part while said getter holding material 13 is held by a lead wire 7 through a getter support 14. Barium getter is in advance filled inside the getter holding material 13 while flushing the getter material 13 from outside, for instance, by heating with a high frequency heating device after forming the tip 12 by vacuum-exhausting the outer tube 9. As a result, a getter coating 15 is formed made of barium on the end part inside surface in the opposite direction to the sealing part of the outer tube 9, namely on the end part inside surface centering about the tip 12 while maintaining the inside of the outer tube high vacuum throughout lamp life.

Description

[Detailed description of the invention] Industrial applications The present invention relates to high intensity discharge lamps.

2. Description of the Related Art Conventional Structures and Problems With the advent of an era of full-fledged energy conservation, the development and commercialization of compact high-intensity discharge lamps to replace low-wattage incandescent light bulbs is actively underway. In particular, in order to use high-pressure sodium lamps and metal halide lamps as the main light source for indoor lighting, small metal halide lamps in the 30- to 70-W class have efficiency comparable to the luminous flux level of 100- to 150-W class incandescent bulbs and high color rendering properties. There are many attempts to develop and commercialize lamps and high-pressure sodium lamps. For example, the applicant is JP-A-57-9046, JP-A-57-607.
In Publication No. 63, etc., a new small-sized high-color-rendering high-pressure
I suggested IJ Um Lamp. Based on this proposal, we prototyped a high-pressure sodium lamp with high color rendering properties that emits a warm light color similar to that of a light bulb, and has an efficiency nearly three times that of a light bulb, even though the lamp input is low wattage (SOW). The arc tube of this lamp is very small, around 5 Q 111 m in length, so the outer bulb of the lamp is formed from a relatively small glass bulb with a shape similar to the arc tube of a halogen lamp.
The features of this arc tube will be fully demonstrated if it is used by being attached to a small reflector that allows a greater degree of freedom in light distribution control. In particular, if a single-ended lamp outer tube is used, it is possible to realize very small, high-intensity, high-pressure discharge lamps, such as conventional high-pressure sodium lamps and metal halide lamps, with a total lamp length of around 100 mm or less. It is something that can be done.

By the way, in high-intensity discharge lamps, it is necessary to provide a getter inside the outer bulb. For example, in the case of a high-pressure sodium lamp, a barium getter is installed to maintain the outer tube in a vacuum during lighting, and in the case of a metal halide lamp, a zirconium getter is installed to capture hydrogen in the outer tube. Common. The low wattage high pressure IJ lamp based on the above proposal is no exception, and requires a barium getter to be provided within the outer bulb. However, the space inside the outer tube is very narrow, so no matter where it is installed, it will be close to the arc tube. Therefore, this getter or getter holding material partially obstructs light emission from the arc tube, and not only reduces the luminous flux of the lamp, but also significantly distorts the light distribution characteristics.

OBJECTS OF THE INVENTION In view of the above-mentioned problems, the present invention provides a high-intensity discharge lamp that does not cause reduction in luminous flux and has improved light distribution characteristics.

Structure of the Invention The present invention comprises a single-ended outer tube in which two long and short leads are sealed, and an arc tube having electrodes at both ends in the tube axis direction of the outer tube. The lamp is characterized by a high-intensity discharge lamp having a getter holding material in the outer bulb and a getter coating on the inner surface of the outer bulb so as to surround the end of the arc tube that is farther from the stop, and which prevents light from the arc tube. This is to ensure that it does not interfere with the release.

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

FIG. 1 shows the structure of a SOW high color rendering, high pressure, l-IJ lamp, which is an embodiment of the present invention. In the same figure, 1 is the inner diameter of the central part, that is, the maximum inner diameter is 5
An electrode conductor 2.3, which is an alumina arc tube of mail, whose diameter is narrowed at both ends, and which is made of a niobium tube with an outer diameter of 211 tln by ceramic cement on the inner surface of both ends.
is sealed. Electrodes 4 and 6 are held at the tip of the electrode conductor 2.3, and the shortest distance between these two electrodes is 10111))t. Further, inside the alumina arc tube 1, a sodium amalgam 6 and a neon/argon mixed gas are sealed as a starting aid gas.

The arc tube 1 is connected to a lead wire 7 via an electrode conductor 2.3.
, held at 8, inner diameter 12.5 nl) n outer diameter 1
It is provided inside the glass outer tube 9 of 5n1J11.

The other ends of the lead wires 7 and 8 are covered with molybdenum metal foil 1.
Welded and connected to the end of 0.11, molybdenum metal foil 1
0.11 is hermetically sealed at one end of the outer tube 9. A tip tube is previously welded to the other end of the outer tube 9, and after the inside of the outer tube 9 is evacuated, the tip tube is sealed and cut to form a tip 12. A ring-shaped getter holding material 13 is provided around the outer periphery of the arc tube end of the outer tube 9 that is far from the sealing part, that is, the tube end to which the electrode conductor 2 is sealed. The getter holding material 13 is held on the lead wire 7 via the getter support 14. The inside of the getter holding material 13 is filled with barium getter in advance, and after the outer tube 9 is evacuated to form the chip 12, the getter holding material 13 is heated from the outside using, for example, a high-frequency heating device to perform flushing. be done.

As a result, a getter coating 15 made of barium is formed on the inner surface of the end of the outer bulb 9 in the direction opposite to the sealing part, that is, the inner surface of the end centering on the chip 12, and the inside of the outer bulb is kept in a high vacuum during the life of the lamp. maintained. Note that a cap 16 is attached to the end of the outer tube 9 on the side where the molybdenum metal foil 10.11 is hermetically sealed.

When we determined the vertical light distribution curve by measuring the luminous intensity in each direction with the light center of the high-pressure sodium lamp 101 having such a configuration, that is, the center of the arc tube 1 as the origin, we found that it was an axially symmetrical curve as shown in FIG. An ideal light distribution curve was obtained.

On the other hand, when the getter holding material is arranged so as to face the inner surface of the outer bulb as shown in Fig. 3, the getter holding shrine and getter coating partially obstruct light emission from the arc tube, and the vertical The light distribution curve takes on an asymmetrical and distorted shape, as shown in FIG.

In this example, the case of a high-pressure I-IJ lamp equipped with a small integrally molded alumina arc tube was explained, but it goes without saying that it can be used with a metal halide lamp as well as a general high-pressure I-IJ lamp. Similarly, when high-intensity discharge lamps such as
Excellent light distribution characteristics without distortion can be obtained by providing a getter holding material inside the outer tube and a getter coating on the inner surface of the outer tube so as to surround the end of the arc tube that is far from the sealing part of the outer tube. Needless to say.

As described in detail, the present invention includes a single-ended outer tube with two long and short tubes partially sealed, and an arc tube having electrodes at both ends in the tube axis direction inside the outer tube. The getter holding material and the getter coating are provided in the outer tube and on the inner surface of the outer tube so as to surround the end of the arc tube that is far from the sealing part of the outer tube. It is possible to provide a high-intensity discharge lamp for direct current lighting that does not prevent light emission from the arc tube, and therefore provides excellent light distribution characteristics without reduction in luminous flux and without distortion.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a small high-pressure sodium lamp which is an embodiment of the present invention, Fig. 2 is a diagram showing a vertical light distribution curve of the high-pressure sodium lamp of the embodiment shown in Fig. 1, and Fig. 3 is a diagram showing a conventional high-pressure sodium lamp. FIG. 4 is a diagram showing the structure of a practical high-pressure sodium IJ lamp, and FIG. 4 is a diagram showing a vertical light distribution curve of the high-pressure sodium IJ lamp shown in FIG. 1... Arc tube, 2, 3... Electrode conductor,
4, 6... Electrode, 6... Sodium amalgam, 7, 8... Lead wire, 9... Outer tube,
10, 11 Mountain/Solid metal foil, 13...
・Getter holding material 1, 14...Getter support,
15... Getter coating, 16... Cap, 101
．． 301...High pressure sodium lamp.

Claims (3)

[Claims] (1) A single-ended outer tube in which two long and short leads are sealed, and an arc tube having electrodes at both ends in the tube axis direction within the outer tube, and the outer tube is sealed. A high-intensity discharge lamp characterized in that a getter holding material is provided in the outer bulb and a getter coating is provided on the inner surface of the outer bulb so as to surround the end of the arc tube that is farther from the outer bulb. (2) The high-intensity discharge lamp according to claim 1, wherein the getter holding material is held on the longer side of the lead. (3) The high-intensity discharge lamp according to claim 1, wherein the getter holding material is held on the conductor portion of the electrode.