JPS5994359A - High pressure discharge lamp - Google Patents

Abstract

PURPOSE:To produce a high pressure discharge lamp easy to restarting, by providing a light emission tube having a heater and a firing tube as a starter while connecting the high voltage generating terminal of firing tube with main electrode of light emission tube having no heater. CONSTITUTION:Upon direct connection of power source to the base of high pressure mercury lamp, discharge is first produced between the fixed electrode 18 and movable electrode 19 of firing tube 15 to flow current through a heater 14 thus to emit electrons. When the movable electrode 19 deforms due to heat through discharge, to contact both electrodes, discharge will stop to stop heating thus to separete the electrodes. Here the ballast 16 will produce surge voltage and since high voltage generating terminal 21 is connected to main electrode 2b, high potential side is applied to main electrode 2b. Consequently electrons emitted from the heater 14 is accelerated toward main electrode 2b to increase conductivity between main electrodes 2a, 2b thus to start discharge and light.

Description

[Detailed Description of the Invention] Conventionally, high-pressure discharge lamps have been used on roads, sports grounds, gymnasiums, factories, etc., but because high-pressure discharge lamps are compact and highly efficient, they have attracted attention as a power-saving light source.
Its use gradually spread to commercial facilities. but,
High pressure discharge lamps have the disadvantage of long restart times.

This high pressure discharge lamp will be explained using a high pressure mercury lamp as an example. Figure 1 shows the structure of a high-pressure mercury lamp, where l is an arc tube made of quartz glass, has a pair of main electrodes 2a and 2b and an auxiliary electrode 3 installed near them, and has mercury inside. Filled with argon gas. Main electrode 2a is connected to stem lead 7a fixed to stem 6 via molybdenum foil 4a and lead 5a. In addition, the main electrode 2b
are connected to the stem lead 7b via the molybdenum foil 4b, the lead 5b and the support frame 9, and the stem lead 7a,
7b is connected to the base 8. Further, the auxiliary electrode 3 is connected to the support frame 9 via a molybdenum foil lO, a lead 11 and a resistor 12. 13 is an outer tube that accommodates each of the above members;
A layer of phosphor is coated on its inner surface, and nitrogen is sealed inside.

In the above-mentioned high-pressure mercury lamp, when a voltage is applied through the ballast, a discharge first occurs between the auxiliary electrode 3 and the main electrode 2a, and this auxiliary discharge causes the main electrodes 2a, 2b to
A discharge occurs between the two, and the lamp lights up.

However, in this high-pressure mercury lamp, the mercury pressure inside the arc tube 1 reaches several atmospheres while the lamp is on, so the power voltage drops temporarily and once the lamp goes out, the power voltage returns to normal. However, the lamp cannot be started immediately, and the luminous tube 1
Lighting could not be performed until the temperature of the arc tube 1 decreased and the pressure of mercury vapor within the arc tube 1 decreased to a state where discharge could begin. The time from when the lamp goes out until it can start discharging again is called the restart time, and high-pressure mercury lamps require 3 to 5 minutes.

Therefore, in order to shorten this restart time, a method is proposed in which a heating element is installed near the main electrode, and upon restarting, this heating element is heated to release electrons into the discharge space, and a voltage is applied between the main electrodes. known to be effective. However, even when the heating element is installed, the voltage required to restart the lamp instantaneously is higher than the power supply voltage, and a starting circuit that generates a high voltage is required to light the lamp.

The present invention has been made in view of the above points, and is provided with an arc tube having a heating body and a lighting tube as a starter, and a terminal for generating high voltage of the lighting tube is connected to the heating body of the arc tube. An object of the present invention is to provide a high-pressure discharge lamp that can be easily restarted by connecting it to a main electrode that does not have a main electrode.

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

FIG. 2 shows the circuit configuration of the high-pressure mercury lamp according to this embodiment, and 13 is an outer tube of the high-pressure mercury lamp, and a heating element 14 is placed near one main electrode 2a in the arc tube 1 provided inside the outer tube.
One end of the heating body 14 is connected to the main electrode 2a, and the other end of the heating body 14 is connected to the other main electrode 2b via a lighting tube 15 as a starter. Further, a power source 17 and a ballast 16 are connected in series between the main electrodes 2a and 2b.

In the above circuit, when the dual source 17 is applied, the ballast 1
6, a voltage is applied between the main electrodes 2a, 2b and between the contacts 18, 19 in the lighting tube 15, causing the lighting tube 15 to generate an electrical discharge via the filled gas. The lighting tube 15 is heated by this discharge, and its contacts 18 and 19 are closed. The heating element 14 is heated because an open current flows between the contacts 18 and 19 of the lighting tube 15, causing discharge and closing.
Emit electrons into the discharge space. On the other hand, the lighting tube 15 has contact 1
When 8°19 closes, the discharge stops, so heating also stops, and contacts 18 and 19 open. At this time, a surge voltage is generated in the ballast 16, this surge voltage is applied between the main electrodes 2a and 2b, and due to the electronic supplementary effect from the heating element 14, a discharge occurs between the main electrodes 2a and 2b, and the lamp is lit. do.

By the way, the inventors conducted various experiments regarding the lighting of the above-mentioned high-pressure mercury lamp, and discovered that a high voltage was generated at one of the two terminals of the lighting tube 15. FIG. 3 shows the structure of the lighting tube 15, in which a fixed pole 18 and a movable pole 19 forming contacts are provided in a glass container, and argon gas is sealed therein. The movable pole 19 is made of bimetal, and the terminals 2 are connected to the fixed pole 18 and the movable pole 19, respectively.
0.

21 is provided. When a voltage is applied between the terminals 20 and 21, a discharge occurs between the fixed pole 18 and the movable pole 19,
The heat of this discharge deforms the movable pole 19 made of bimetal, and the movable pole 19 comes into contact with the fixed pole 18 . Therefore, the discharge stops and the heating also stops, and the movable pole 19 changes to the fixed pole 1.
Stay away from 8.

At this time, a surge voltage is generated in the ballast 16, but in this case, one of the terminals 20 and 21 always generates a high voltage. That is, the lighting tube 15 repeats the discharge in an extremely short period immediately after the movable pole 19 separates from the fixed pole 18, and a surge voltage is generated in the ballast 16 in response to this, but the fixed pole 18 Since the materials and shapes of the movable electrode 19 and the movable electrode 19 are different from each other, there is a difference in the start of discharge when the potential becomes negative when an AC voltage is applied. In the case of FIG. 3, discharge is likely to occur when the movable electrode 19 has a negative potential, and is difficult to cause when the movable electrode 19 has a positive potential. Therefore, a high voltage was generated on the terminal 21 side, for example, a surge voltage of about 2KV was generated on the terminal 21 side, and a surge voltage of about IKV was generated on the terminal 20 side.

FIG. 4 shows the specific structure of the high-pressure mercury lamp according to this embodiment, in which 2a and 2b are main electrodes provided at both ends of the arc tube 1, and 14 is a heating element provided near the main electrode 2a. be. Main electrode 2a is molybdenum foil 4a s lead 5
a, stem door a, connected to base 8 via lead 22, ballast 16 and lead 23; Further, the main electrode 2b is connected to the base 8 via the molybdenum foil 4b, the lead 5b, the support frame 9, the stem lead 7b, and the lead 24.

One terminal of the heating body 14 is welded to the molybdenum foil 4a, and the other terminal is connected to the terminal 20 of the lighting tube 15 via the molybdenum foil 25, lead 26, stem lead 7C, and lead 27. The terminal 21 of is connected to the stem lead 7b via a lead 28. On the outer surface of the arc tube l is a starting aid 29 made of a 0.1φ molybdenum wire.
It has the effect of lowering the starting voltage. Both ends of the starting auxiliary body 290 are connected to the support frame 9. Arc tube 1
The inner surface of the outer tube 13 containing the components is coated with phosphor, and the inside is filled with nitrogen. The arc tube 1 has an inner diameter of 6 mm and a distance of 16 Wrm between the main electrodes 2a and 2b.

It has an internal volume of 0.57ω and is filled with mercury and argon. Each of the stem leads 7a to 7C is hermetically inserted into the outer tube 13, and the lighting tube 15, ballast 16, etc. are housed in a case 30 that is integrally provided between the outer tube 13 and the base 8.

In the above high-pressure mercury lamp, the power source 1 is connected directly to the base 8.
7 is connected, a discharge occurs between the fixed pole 18 and the movable pole 1'9 of the lighting tube 15, causing heating.

A current flows through the body 14, and electrons are emitted from the heating body 14. When the movable pole 19 is deformed by the heat of the discharge and the two poles come into contact, the discharge stops and heating stops, causing the two poles to separate.

At this time, the ballast 16 generates a surge voltage, and since the terminal 21 that generates a high voltage is connected to the main electrode 2b, the high potential side of the surge is applied to the main electrode 2b. As a result, the electrons emitted from the heating body 14 are accelerated toward the main electrode 2b, so that the conductivity between the main electrodes 2a and 2b increases, and discharge is started to turn on the lamp. The discharge starting voltage when restarting a conventional high-pressure mercury lamp was about 4", but the discharge starting voltage of the high-pressure mercury lamp of this embodiment was about 1.5".
It decreased to ■.

In addition, although the above embodiment described a high-pressure mercury lamp,
The present invention is also applicable to high pressure discharge lamps such as high pressure sodium lamps and metal halide lamps.

Further, the high-pressure discharge lamp of the present invention may be one that includes at least an arc tube having a heating element and a lighting tube. For example, it may be one that has an impedance element such as a resistor or a filament connected in series with the lighting tube. good.

As described above, the high-pressure discharge lamp of the present invention includes an arc tube having a heating element and a lighting tube, and the terminal of the lighting tube on the side that generates high voltage is connected to the side of the arc tube where the heating element is not provided. Since it is connected to the main electrode of the main electrode, the electrons emitted due to the heating body are accelerated in the direction of the high potential main electrode on the side where the heating body is not provided. Therefore, discharge between the main electrodes is likely to occur, and the discharge starting voltage at the time of restart is lowered, making restart easier.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a conventional high-pressure mercury lamp, Fig. 2 is a circuit diagram of a high-pressure mercury lamp according to the present invention, Fig. 3 is a block diagram of a lighting tube according to the present invention, and Fig. 4 is a block diagram of a high-pressure mercury lamp according to the present invention. FIG. 2 is a configuration diagram of such a high-pressure mercury generator. 1... Arc tube, 2a, 2b... Main electrode, 13.-
- Outer tube, 14... Heating element, 15... Lighting tube, 20.
21...Lighting tube terminal. Note that the same reference numerals in the figures indicate the same or similar parts. Agent Shin Kuzuno - Fig. 1 Fig. 2 Fig. 4 ↑ζ 1, Director General's Palace 1, Indication of the case Patent Application No. 1987-205011 2
Title of the invention: High-pressure discharge lamp 3. Relationship with the amended person's case Patent applicant address: Chiyo, Tokyo [2-2-3 Marunouchi, B-ku]
Name (601) Mitsubishi Electric Corporation Representative Hitoshi Katayama 4, Agent address Mitsubishi Electric Corporation 5, 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Details of the invention in the specification subject to amendment Explanation column 6, Statement of contents of amendment, page 8, line 14 r 1.5VJ'er 1.5ffj
and correct it.

Claims (1)

[Claims] (1) Equipped with an arc tube that has a pair of main electrodes at its ends and a heating element near one of the main electrodes, and a lighting tube as a starter, the two terminals of this lighting tube Of these,
A high-pressure discharge lamp characterized in that the terminal on the side that generates high voltage is connected to the main electrode on the side of the arc tube that is not provided with a heating element.