JPH0322019B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-pressure discharge lamp with a glow starter as starter.

One way to operate high-pressure sodium lamps and metal halide lamps with choke-type ballasts is to connect a glow starter in parallel with the arc tube and store it inside the outer bulb, so that when the power supply voltage is applied, the glow starter's operation generates electricity in the ballast. A method of starting the discharge of an arc tube using pulse voltage has been put into practical use. In this type of lamp, if the short-circuit current of the ballast is relatively small, 1A or less, the glow starter can be directly connected in parallel to the arc tube. However, if the short circuit current of the ballast is relatively large, it is difficult to manufacture a glow starter with a large allowable current, so generally a current limiting resistor is connected in series with the glow starter 1 as shown in Figure 1. The structure is such that the current flowing through the glow starter 1 is suppressed to about 1A or less by connecting the body 2. When discharge of the arc tube 3 starts due to the pulse voltage generated in the ballast 4 due to the operation of the glow starter 1, the terminal voltage of the glow starter 1 decreases to the arc tube voltage, so the glow starter 1 does not operate again. When the temperature of the glow starter 1 rises due to heat due to radiation and conduction from the arc tube 3 and its contacts are closed, the arc tube 3 becomes inconveniently turned off.
In order to prevent such inconvenience, a bimetal switch 5 is connected in series to the glow starter 1. This bimetal switch 5 is the arc tube 3
The bimetallic switch 5 is configured to open the circuit after the arc tube 3 starts discharging before the temperature of the glow starter 1 reaches its closing temperature.

However, such a conventional high-pressure discharge lamp with a built-in glow starter has a problem in that it takes a long time for the light output to rise immediately after the start of discharge.

The present invention provides a high-pressure discharge lamp with a built-in glow starter that can solve the above problems with a simple configuration and can minimize power loss during lighting.

The present invention will be described below with reference to the drawings, taking a high-pressure sodium lamp as an example.

FIG. 2a is a front view showing the structure of an embodiment of the high-pressure discharge lamp according to the present invention, and FIG. 2b is a circuit diagram thereof.

In Figure 2a, 3 is an arc tube which is equipped with a pair of electrodes at both ends of an alumina ceramic tube, and is filled with sodium amalgam and a rare gas for starting, and in series with this is a current limiting resistor made of a tungsten filament. Functional light-emitting resistor 7
is connected. A thermally responsive switch, such as a bimetal switch 6, which is open at room temperature and closed by heat from the arc tube 3 several minutes after the arc tube 3 starts discharging, is connected in parallel to the light emitting resistor 7. 8 is an insulator for supporting the bimetal switch 6. The glow starter 1 is connected in parallel to the arc tube 3 via a bimetallic switch 5 which is closed at room temperature and becomes open due to heat from the arc tube 3. The operating time of the bimetal switch 6 must be determined taking into consideration the light output rise characteristics of the arc tube used, but assuming that the time it takes for the light output of the arc tube 3 to reach a nearly stable state is 5 minutes, After the discharge of the arc tube 3 starts, the bimetal switch 6
Set the circuit so that it closes in 2 to 3 minutes. On the other hand, as mentioned above, the bimetal switch 5 connected in series to the glow starter 1 needs to be opened after the start of discharge before the temperature of the glow starter 1 reaches its closing temperature. Bimetal switch 6: Return time after lights out
It must be set to be longer than . This is because when the power supply voltage is reapplied immediately after the lamp goes out, if the bimetal switch 5 returns first, the light emitting resistor 7 is still short-circuited by the bimetal switch 6, so the short-circuit current of the ballast 4 This is because the fuel will flow directly to the glow starter 1.

The glow starter 1, the arc tube 3, etc. are provided inside the outer tube.

Now, in the above configuration, via the stabilizer 4
200V at power supply 8 for a 100W high pressure sodium lamp
When a voltage of At the same time, the current flowing to the glow starter 1 is limited by this light emitting resistor. Thereafter, the glow starter 1 is opened, thereby generating a high voltage in the ballast 4, which is applied to the arc tube 3, and the arc tube 3 starts discharging. Bimetal switch 5
becomes an open circuit state due to the heat from the arc tube 3. On the other hand, the bimetal switch 6 is closed and short-circuits the light-emitting resistor 7, thereby preventing power loss due to the light-emitting resistor 7 during lighting.

Now, the 100W high-pressure sodium lamp mentioned as an example has a lamp voltage of 100V, a luminous flux of 4500lm, and a color temperature of 2500K, and the short-circuit current of the ballast 4 at a power supply voltage of 200V is about 2A. Light emitting resistor 7
If a 140V, 1A, 20lm/W tungsten filament is used, the current flowing through the glow starter 1 when starting the lamp will be approximately 1A, and a luminous flux of approximately 2500lm will be obtained from the tungsten filament immediately after the arc tube 3 starts discharging. It will be done.

FIG. 3 shows the change in luminous flux value after the start of discharge in comparison with a conventional lamp. In the figure, A shows the case of the high-pressure sodium lamp according to the present invention, and B shows the case of the conventional high-pressure sodium lamp. As is clear from this, according to the high-pressure sodium lamp according to the present invention, a certain brightness can be obtained by the light-emitting resistor immediately after the start of discharge, and the rise characteristics of the light output are improved.

In the above explanation, a high-pressure sodium lamp was taken as an example, but it goes without saying that the present invention can also be applied to high-pressure mercury lamps, metal halide lamps, and the like.

According to the present invention, the rise characteristics of the light output of a high-pressure discharge lamp can be adjusted by utilizing the current-limiting resistor that was originally required to limit the current of the glow starter and by adding one new bimetal switch. This can be greatly improved, and power loss caused by the light emitting resistor during lighting can be eliminated.
Its practical effects are great.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a conventional high pressure discharge lamp. Fig. 2a is a front view showing the structure of a high-pressure discharge lamp that is an embodiment of the present invention, Fig. 2b is a circuit diagram thereof, and Fig. 3 is a comparison of the light output rise characteristics of the product of the present invention and a conventional product. FIG. 1... glow starter, 3... luminous tube, 4...
Stabilizer, 5, 6... Bimetal switch, 7...
Luminescent resistor.

Claims (1)

[Claims] 1 Inside the outer bulb, a light emitting resistor having a current limiting resistance function is connected in series with the light emitting tube, and a glow starter is connected in parallel to the light emitting tube via a first thermally responsive switch that is closed at room temperature and open at high temperature. A second thermally responsive switch that is open at room temperature and closed at high temperature is connected in parallel to the light emitting resistor, and when the first thermally responsive switch is in the closed state, the second thermally responsive switch is connected to the light emitting resistor. A high-pressure discharge lamp characterized in that the switch is configured to be in an open state.