JPH083990B2 - Discharge lamp - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to discharge lamps.

Conventional Technology In the era of full-scale energy conservation, development and commercialization of small high-intensity discharge lamps that replace low-watt incandescent light bulbs have been actively pursued. In particular, in order to use high-pressure sodium lamps and metal halide lamps as the main light source for indoor lighting, small high-pressure sodium in the 30-70W class with efficiency and high color rendering comparable to the luminous flux level of incandescent bulbs in the 100-150W class. Development and commercialization of lamps and metal halide lamps are being actively attempted. For example, JP-A-61-4554
A new small high-pressure sodium lamp is proposed in Japanese Patent Publication No. As shown in FIG. 2, these lamps have electrode conductors 2 and 3 sealed at both ends of an arc tube 1, and electrodes 4 and 5 are held at the tips of the electrode conductors 2 and 3. There is. Inside the arc tube 1, sodium amalgam 6 and a starting aid gas are enclosed. Arc tube 1 is electrode conductor 2,3
It is held in the outer tube 9 by lead wires 7 and 8 made of molybdenum that are inserted inside. The other ends of the lead wires 7 and 8 are connected to the ends of the metal foils 10 and 11 made of molybdenum by welding, and the metal foils 10 and 11 are hermetically sealed to the ends of the outer tube 9. A tip tube is connected to the other end of the outer tube 9 in advance, and after the inside of the outer tube 9 is evacuated to a vacuum, it is sealed and cut into a chip 12. Further, a getter holding member 18 is held by the lead wire 7 in the vicinity of the tube end where the electrode conductor 2 is sealed. The getter holding member 18 is filled with an alloy getter 16 of zirconium and aluminum so as to maintain a high vacuum inside the outer tube 9 during the life of the lamp.

Problems to be Solved by the Invention In such a small-sized high-pressure sodium lamp, the getter holding member 18 is bent so that the wide getter holding member 18 can be inserted into the outer tube 9 having a small inner diameter. To narrow the width. However, when the lead wire 7 is welded to the getter holding member 18 that has been bent as described above, the mounting angle of the getter holding member 18 with respect to the lead wire 7 (the center axis of the lead wire 7 and the getter holding member 18 The angle formed by the surface of the getter material filled in the central hole is likely to vary. Since the getter temperature is determined by the heat conduction and the heat radiation of the arc tube 1, if the mounting angle of the getter holding member 18 varies, the getter temperature varies, the getter does not operate normally, and the life characteristics of the lamp vary. There was a point.

The present invention has been made to solve such a problem, and provides a discharge lamp in which variations in lamp life characteristics are prevented.

Means for Solving the Problems In the discharge lamp of the present invention, a getter is provided on at least one of the conductors, one end of which is connected to the lead wire and the other end of which is connected to the electrode conductor sealed to the end of the arc tube. It has an attached structure.

Operation With this configuration, it is possible to minimize variations in the getter installation position with respect to the arc tube, that is, variations in the getter temperature.

EXAMPLE FIG. 1 shows a 50 W high color rendering high pressure sodium lamp which is an example of the present invention. In FIG. 1, in the high color rendering high pressure sodium lamp of the embodiment of the present invention, electrode conductors 2 and 3 are sealed at both ends of an arc tube 1, and electrodes 4 and 5 are attached to the tip ends of the electrode conductors 2 and 3. 5 is held. Inside the arc tube 1, sodium amalgam 6 and a starting aid gas are enclosed. The arc tube 1 is held in the outer tube 9 by arc tube support plates 14 and 15 having one end connected to the lead wires 7 and 8 and the other end connected to the electrode conductors 2 and 3. The other ends of the lead wires 7 and 8 are connected to the ends of the metal foils 10 and 11 made of molybdenum by welding, and the metal foils 10 and 11 are hermetically sealed to the ends of the outer tube 9. . A tip tube is connected to the other end of the outer tube 9 in advance. After the inside of the outer tube 9 is evacuated to a vacuum, the chip is sealed and cut to form a chip 12. Arc tube support plate 14,1
Alloy getters 16 and 17 of zirconium and aluminum are attached to the respective parts 5 to maintain a high vacuum inside the outer tube 9 during the lamp life.

As described above, according to the high color rendering high pressure sodium lamp of the embodiment of the present invention, the arc tube supporting plates 14 and 15 do not need to be bent and used unlike the conventional ones, so that the lead wires 7 and 8 at one end thereof are not used. Welding becomes much easier than before.
Further, since the other end portions of the arc tube support plates 14 and 15 are also fixed to the electrode conductors 2 and 3 by welding, the attachment positions thereof are constant unlike the conventional case. As a result, arc tube support plates 14,1
The temperature variations of the getters 14 and 15 attached to 5 are suppressed as much as possible, and the lamp life characteristics are stabilized.

In the above embodiment, the case where the arc tube support plate is used for supporting the arc tube and supplying the arc tube current has been described.
A conductor made of a conductive wire may be used instead of the arc tube support plate.

Further, the getter does not adhere to both of the conductors, and the same effect can be obtained with only one of the conductors.

EFFECTS OF THE INVENTION As described above, according to the present invention, by applying a getter to the arc tube support plate connected to the two long and short lead wires, it is possible to suppress variations in the getter installation position with respect to the arc tube as much as possible. Therefore, the getter temperature does not vary, and the getter operating temperature can be normally set. As a result, the present invention can provide a discharge lamp having an excellent effect that stable lamp life characteristics can be obtained without variations in lamp life characteristics due to getter operation failure.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a high pressure sodium lamp according to an embodiment of the present invention, and FIG. 2 is a partially cutaway front view of a conventional high pressure sodium lamp. 1 ... Arc tube, 2, 3 ... Electrode conductor, 4,5 ... Electrode, 6 ...
Sodium amalgam, 7,8 ...... Lead wire, 9 …… Outer tube, 14,15 …… Arc tube support plate, 16,17 …… Getter, 18 ……
Getter holding member.

Claims (1)

[Claims] 1. An outer tube in which two long and short lead wires are sealed, and an arc tube provided in the outer tube in the axial direction of the tube and having electrodes at both ends, wherein one end side is the lead. A discharge lamp, wherein a getter is attached to at least one of conductors connected to a wire and the other end of which is connected to an electrode conductor sealed to the end of the arc tube.