JPH09320535A - Metal halide lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a built-in starter type metal halide lamp whose restarting performance is enhanced by lowering the temperature of an FEC (nonlinear ferroelectric ceramic capacitor) to a temperature at which a voltage of 500V or more is produced, within a predetermined restarting time. SOLUTION: In a metal halide lamp, in which a starter using an emission tube 11 and an FEC 15 is enclosed in a lamp outer bulb 21 having N2 gas sealed therein, and which is turned on with a base 20 facing upward, the distance Y[mm] from the emission tube center of the FEC constituting the starter to an arranged position in the direction of a lamp outer bulb base is set to meet 0.1X+45<=Y<=0.1X+65 where X[W] is lamp power.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal halide lamp having a built-in starter having a series circuit of a non-linear ferroelectric ceramic capacitor (hereinafter abbreviated as FEC) and a semiconductor switch. Regarding metal halide lamps.

[0002]

2. Description of the Related Art Conventionally, various types of metal halide lamps having a built-in starter having a series circuit of an FEC and a semiconductor switch have been known. In No. 256104, a metal halide lamp having a structure as shown in FIG. 6 was proposed. FIG.
1 has a pair of main electrodes 2a and 2b and a starting auxiliary electrode 3 provided close to one of the main electrodes, and a metal halide such as scandium iodide is enclosed in the interior together with mercury and a rare gas. It is an arc tube made of. A series circuit of an FEC 5 and a semiconductor switch 6 is connected in parallel to the arc tube 1 via a thermoresponsive switch (bimetal switch) 4 having a room temperature closed contact. A resistor 7 is connected between the starting auxiliary electrode 3 of the arc tube 1 and the other main electrode 2a via the heat responsive switch 4, and the ON phase of the semiconductor switch is stabilized in parallel with the semiconductor switch 6. A resistor 8 for converting the FEC 5 and the semiconductor switch 6 is connected in parallel to the series circuit of the FEC 5 and the semiconductor switch 6. Each of these constituent elements is housed inside a lamp outer bulb filled with N ₂ gas, and constitutes a metal halide lamp 10.

The metal halide lamp 10 thus constructed is connected to an AC power source 12 via a choke type ballast 11 and is turned on. That is, when the AC power supply 12 is turned on, a sine wave power supply voltage is applied to the starter via the choke type ballast 11.
At the time when the applied voltage exceeds the breakover voltage of the semiconductor switch 6, a stepwise steep voltage is applied to the FEC 5, whereby the FEC 5 is rapidly charged and reaches the saturation voltage immediately, and the current is rapidly cut off. To do. At this time, a pulse voltage having a large amplitude is generated in each cycle due to the inductance L of the ballast 11, and this is applied together with the power supply voltage between the main electrode 2b of the arc tube 1 and the starting auxiliary electrode 3 close to the main electrode 2b. A discharge occurs between the electrodes. Subsequently, this discharge is transferred between both main electrodes and the lamp is started.

When the lamp is started, radiant heat of the arc tube 1 opens the heat-actuated switch 4 to disconnect the series circuit of the FEC 5 and the semiconductor switch 6 from the power supply, so that the generation of the high voltage pulse is stopped. By the way, generally, in a metal halide lamp having a starting auxiliary electrode, a potential of about 15 V is applied between the auxiliary electrode and the main electrode while the lamp is lit, and if the FEC is inserted in this electric circuit, This potential is applied between both electrodes of the FEC, and this potential causes silver, which is the main component of the electrode film material of the FEC, to diffuse into the element, degrading the nonlinear characteristics. This phenomenon is F
This occurs when a potential of 3 to 5 V or higher is applied in a high temperature state above the Curie temperature of EC, the characteristics deteriorate, and the generated pulse voltage decreases. Therefore, in the metal halide lamp having the above-mentioned configuration, the value of the resistance connected in parallel to the series circuit of the FEC and the semiconductor switch is selected to be 10 kΩ to 100 kΩ to reduce the potential applied to the FEC during lamp lighting. To prevent deterioration of FEC characteristics,
The generation of high pulse voltage can be maintained at the time of starting. The resistor connected in parallel to the series circuit of the FEC and the semiconductor switch is placed close to the FEC, and when the lamp fails, the FEC is heated above the Curie point (90 ° C) to generate a pulse. It also has a function to stop.

[0005]

However, in the metal halide lamp with a built-in starter having such a structure,
There is no problem in cold start (ambient temperature is -5 ℃ to 40 ℃), but after restarting after turning off the lamp once and turning on the power to wait for the lamp to light up, the restart time varies. It is difficult to stably generate an appropriate pulse voltage (about 500 V or more) because there is (9 minutes after turning off the lamp and within 15 minutes). This is because the pulse voltage is attenuated by the addition of the pulse stop function and the temperature of the FEC that constitutes the starter at the time of restart is high, and it does not drop rapidly to the temperature (about 80 ° C) that generates a pulse voltage of 500V or more. This is due to the reason.

The present invention has been made in order to solve the above-mentioned problems in the conventional metal halide lamp with a built-in starter using the FEC.
It is an object of the present invention to provide a metal halide lamp with a built-in starter capable of lowering the FEC temperature to a temperature at which a pulse voltage of 500 V or higher is generated (about 80 ° C. within 15 minutes after the minute).

[0007]

In order to solve the above problems, the present invention provides a pair of main electrodes and a starting auxiliary electrode near one of the main electrodes, and a metal halide together with mercury and a rare gas are provided inside. A sealed arc tube, a series circuit of a non-linear ferroelectric ceramic capacitor and a semiconductor switch connected between the main electrodes of the arc tube via a thermally responsive switch, and a first circuit connected in parallel to the series circuit. The arc tube includes a resistor and a second resistor connected in parallel with the semiconductor switch, and a third resistor connected between the other main electrode and the starting auxiliary electrode through the thermoresponsive switch. in the metal halide lamp to be turned in the upward mouthpiece comprising housed in a lamp envelope spheres encapsulating N ₂ gas and a starter for starting light emission of the non-linear ferroelectric ceramic capacitor constituting the starter The distance Y (mm) to the position of the lamp envelope sphere cap direction from the center, when the lamp power is X [W], is to set so as to satisfy 0.1 X + 45 ≦ Y ≦ 0.1 X + 65,.

By thus setting the position of the FEC, it is possible to easily lower the temperature of the FEC to a temperature (about 80 ° C.) at which a predetermined pulse voltage (500 V or more) is generated at restart. Therefore, the restart performance can be significantly improved.

[0009]

Next, an embodiment will be described. FIG. 1 is a plan view showing a metal halide lamp according to an embodiment of the present invention with a part thereof omitted, and in this embodiment, a 400 W metal halide lamp with a built-in FEC starter is shown. In FIG. 1, reference numeral 11 denotes a light emitting tube, and the light emitting tube 11 is provided with a pair of main electrodes 12 at both ends.
A starting auxiliary electrode 13 is provided in the vicinity of, and a metal halide such as scandium iodide is enclosed in the interior together with mercury and a rare gas. And the total length of arc tube 11 is 102
The arc length is 46 mm in mm. 14 is a heat-actuated switch having a normally closed contact, one end of which is connected to one main electrode, and 15 is an F
EC, 16 is a semiconductor switch, 17 is a third resistor whose one end is connected to the starting auxiliary electrode 13, 18 is a second resistor which is connected in parallel to the semiconductor switch 16, 19 is FEC15 and a semiconductor switch
A first resistor connected in parallel to 16 series circuits, each of which is connected in the same manner as in the conventional example shown in FIG. Except for the semiconductor switch 16, it is housed together with the arc tube 11 in the outer bulb 21 of the lamp to form a metal halide lamp.

The metal halide lamp thus constructed has a total lamp length of 290 mm, the distance from the end of the base to the center of the arc tube is 185 mm, and the maximum diameter of the outer bulb of the lamp is 116 m.
m, the distance Y from the center of the arc tube to the FEC location is 95 m
m, which is a constituent feature of the present invention, is 0.1 X + 45 ≦ Y ≦ 0.1
It satisfies the X + 65 relationship. Further, as the FEC 15 in this embodiment, a silver electrode film having a diameter of 16 mm is formed on both sides of a disk-shaped sintered body having a diameter of 18 mm and containing barium titanate (BaTiO ₃ ) as a main component. In addition to the above, the one in which the electrode film is overcoated with an inorganic glass is used. Curie point of this FEC is about 90 ℃
It is. As the semiconductor switch 16, a bidirectional two-terminal thyristor having a voltage V _BO of about 150 V is used for breakover. The first, second and third resistors have resistance values of 22 kΩ, 30 kΩ and 100 kΩ, respectively.

Then, when the metal halide lamp thus constructed is lit by the method of upper base and once turned off and then the power is immediately turned on, the thermal responsive switch 14 is closed after about 10 minutes, and at that time, the temperature of the FEC changes. About 60 ℃, arc tube 11
The pulse voltage applied between the main electrodes of was about 670 V, and could be easily restarted.

According to the present invention, in a metal halide lamp with a built-in starter using an FEC, the distance Y [mm] from the center of the FEC arc tube to the arrangement position in the lamp base direction is
When the lamp power is X [W], 0.1 X + 45 ≦ Y ≦ 0.
The setting is made so as to satisfy 1 X + 65. Next, the experiment conducted for the setting will be described.

First, in a metal halide lamp with a built-in FEC starter having a pulse stopping function of 400 W having the same structure as that of the embodiment shown in FIG. 1, as shown in the schematic view of FIG. Five types of lamps were created with the distance L from the center to the placement position of the FEC22 changed from 75 mm to 115 mm, and the temperature change of the FEC after the lamp was turned off was measured with time, and the results shown in Fig. 3 were obtained. Was given. The structure and size of each part of the lamp are the same as those shown in the embodiment shown in FIG.
In a windless condition, the light was turned on for 30 minutes and then turned off, and the measurement was performed.

As can be seen from the measurement results shown in FIG.
95 EC from the light center of the lamp (the center of the arc tube) toward the base
It was found that the temperature was the lowest at the position of mm, and the temperature tended to be higher at the position further away. This tendency is hardly affected by the supporting member of the FEC, and is considered to be due to the non-uniformity of the temperature distribution due to the convection mode of the N ₂ gas enclosed in the outer bulb of the lamp. That is, in the portion too far from the center of the arc tube, N
It is considered that the convection of the _two gases is not performed smoothly, and the high temperature N ₂ gas stagnates to prevent the temperature from decreasing.

Next, based on the results shown in FIG. 3, an experiment was conducted to examine the relationship between the restart time and the generated pulse voltage, and the results shown in FIG. 4 were obtained.

Further, for the lamp that is the most difficult to restart, the lamp was turned on for 30 minutes after the lamp was manufactured and then turned off, and the restart test 9 minutes later was performed. Table 1 shows the results obtained by investigating the number of restarted books.

[0017]

[Table 1]

As can be seen from Table 1 above, by setting the position of the FEC to the position of 95 ± 10 [mm] from the center of the arc tube, the pulse voltage is restarted (within 9 minutes and 15 minutes after the lamp is turned off). Occurs over 500 [V] and the restart probability is 100
It turned out that it can be made into%.

The above restart probability experiment was performed at 250 W and 7
When I did the same with the 00W lamp (10 lamps each),
The result as shown in FIG. 5 was obtained. In FIG. 5, the circle marks show the restart probability of 100%, the x marks show less than 100%, and the results of 400 W shown in Table 1 are also shown.

From the results shown in FIG. 5, the distance Y [mm] from the center of the arc tube of the FEC to the arrangement position and the lamp power X
It has been found that there is a relation of linear equation Y = aX + b with [W], and when the coefficients a and b are obtained, a = 0.1,45
≦ b ≦ 65. Therefore, in the present invention, when the lamp power is X [W], the distance Y [mm] from the center of the FEC arc tube to the arrangement position in the lamp base direction is 0.1 X.
It is set to satisfy + 45 ≦ Y ≦ 0.1 X + 65.

[0021]

As described above based on the embodiments, the present invention is such that the distance Y [mm] from the center of the FEC arc tube to the arrangement position in the lamp outer bulb base direction and the lamp power X [ W], 0.1 X + 45 ≦ Y ≦ 0.1 X + 65 is set, so that the FEC temperature can be easily lowered to a temperature at which a predetermined pulse voltage is generated at the time of restart, and the restart performance is improved. Can be significantly improved.

[Brief description of drawings]

FIG. 1 is a partially omitted plan view showing an embodiment of a metal halide lamp according to the present invention.

FIG. 2 is a schematic diagram of a lamp used in an experiment conducted for setting the arrangement position of the FEC in the present invention.

FIG. 3 is a diagram showing a temperature change of the FEC after the lamp is turned off in the lamp in which the arrangement position of the FEC is changed.

FIG. 4 is a diagram showing a relationship between a restart time and a generated pulse voltage in a lamp in which an FEC arrangement position is changed.

FIG. 5 is a diagram showing results of restart probability tests of 250 W, 400 W and 700 W lamps.

FIG. 6 is a circuit configuration diagram showing a configuration of a conventional metal halide lamp with a built-in FEC starter.

[Explanation of symbols]

 11 Arc tube 12 Main electrode 13 Starting auxiliary electrode 14 Thermal switch 15 FEC 16 Semiconductor switch 17, 18, 19 Resistance 20 Base 21 Lamp outer bulb

Claims (1)

[Claims] 1. A light emitting tube comprising a pair of main electrodes and a starting auxiliary electrode in the vicinity of one of the main electrodes, in which a metal halide is enclosed together with mercury and a rare gas, and between the main electrodes of the light emitting tube. A series circuit of a non-linear ferroelectric ceramic capacitor and a semiconductor switch connected via a thermal switch, a first resistor connected in parallel with the series circuit, a second resistor connected in parallel with the semiconductor switch, and the other A starter for starting the arc tube, which is composed of a third resistor connected between the main electrode and the auxiliary start electrode via the thermally responsive switch, and a lamp in which N ₂ gas is sealed. In a metal halide lamp that is turned on with the base housed inside the outer bulb, the distance from the center of the arc tube of the nonlinear ferroelectric ceramic capacitor that constitutes the starter to the position of the lamp in the outer bulb base direction. A [mm], the lamp power X [W]
The metal halide lamp is characterized by being set so as to satisfy 0.1 X + 45 ≦ Y ≦ 0.1 X + 65.