JPH0434834A - Metal halide lamp - Google Patents

Abstract

PURPOSE:To prevent early deterioration and also ensure restarting a lamp by composing a starter with a nonlinear condenser in which the outer peripheral edge part of a ferroelectric ceramic substrate is not covered with ferroelectric crystallization glass. CONSTITUTION:A nonlinear condenser (FEC) 116, in which electrode films 122a and 122b are formed on both the surfaces of a conductive ceramic substrate 121, is coated with ferroelectric crystallization glass 123a and 123b except a lead wire connection part and the peripheral edge part of the substrate 121, and is connected to lead wires 125a and 125b with conductive adhesives 124a and 124b used to the films 122a and 122b. Also a FEC side thermal switch 115b is mounted on a position nearer to a luminous tube 13 than an auxiliary electrode side thermal switch 115a and becoming high temperature. This can ensure restarting a lamp and prevent the early deterioration of the FEC itself.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a metal halide lamp comprising a starter made of a nonlinear capacitor housed together with an arc tube inside an outer bulb of the lamp.

[Prior Art] Metal halide lamps have a spectrum covering the entire visible range, have excellent color rendering properties, and have good luminous efficiency, so they are widely used in the field of lighting for sports, commercial facilities, and the like.

By the way, in order to start this metal halide lamp, a starter such as a glow switch has conventionally been built into the outer bulb of the lamp, but recently nonlinear capacitors have been used in place of the glow switch.

FIG. 5 shows a circuit example of such a metal halide lamp. This consists of a pair of main electrodes 11a and llb, and the main electrode 1
The auxiliary electrode 12 of the arc tube 13 has an auxiliary electrode 12 provided close to at least one of 1a and llb, for example, llb, and has metal halide sealed therein together with mercury and a rare gas. and the other main electrode 11a via a thermal switch 15a, and a starter consisting of a nonlinear capacitor (hereinafter referred to as rFECJ) 16 is connected between the amphibious electrodes 11a and llb via a thermal switch 15b. is housed within the lamp outer bulb 17. 18 is a choke coil, and 19 is an AC power source.

In addition, in the above lamp, FEC1 that constitutes the starter
6, Japanese Patent Application Laid-open No. 60-52006 and Japanese Patent Application Laid-open No. 6
0-136151, etc., as shown in FIG. 6, a disk-shaped ferroelectric ceramic substrate 6
Electrode films 62a and 62b are formed on both sides of the electrode film 1, and the entire surface except for the lead wire connection portions thereof is covered with ferroelectric crystallized glass 63, and the electrode films 62a and 62b are coated with conductive adhesive 64a and 64b. One in which lead wires 65a and 65b are connected is used.

Since the metal halide lamp according to the illustrated example is roughly configured as described above, when voltage is applied to the starter via the choke coil 18 while the arc tube 13 is off, the voltage is applied via the thermal switch 15b. FEC16 starts oscillating. At the same time, the pulse voltage generated by the oscillation of the FEC 16 and the secondary voltage of the choke coil 18 are applied to the auxiliary electrode 12 via the starting resistor 14, and a discharge occurs between the auxiliary electrode 12 and the main electrode 11b.

Therefore, discharge is likely to occur between the main electrodes 11a and llb of the arc tube 13, and a discharge is started between the ambidextrous electrodes 11a and llb due to pulse oscillation by the FEC 16.
The arc tube 13 lights up.

On the other hand, after the lamp is lit, the thermal switches 15a and 15b are heated by the heat generated by the arc tube 13, and both switches 15a and 15b are turned off. As a result, the oscillation of the FEC 16 is also stopped.

[Problems to be Solved by the Invention] However, in the conventional metal halide lamp as described above, there is a problem in that although a starting pulse is generated when restarting the lamp, the lamp may not be able to be lit.

As a result of detailed investigation into the cause of this problem, it was found that it is based on two major factors. That is the structure of FEC.

That is, as shown in FIG. 6, if the entire ferroelectric ceramic base 61 constituting the FEC is covered with ferroelectric crystallized glass 63, the ferroelectric ceramic base 61 will be covered when the FEC oscillates. Because vibrations are suppressed,
This makes it difficult to generate a pulse voltage with a high peak value and high energy. In particular, in order to reliably restart a metal halide lamp, it is necessary to apply a pulse voltage with a large amount of energy, so the FEC having the above structure is inappropriate.

Another reason why the lamp cannot be restarted is related to the return operation of the thermal switch 15b on the FEC side and the thermal switch 15a on the auxiliary electrode side.

That is, while the lamp is on, both thermal switches 15a,
15b are both in the OFF state, but when the lamp is turned off and restarted, they are cooled down and become ON state earlier than the FEC side thermal switch 15b or the auxiliary electrode side thermal switch 15a. The FEC 16 starts oscillating without discharging between the two. For this reason, a situation continues in which it is difficult to start a discharge between the main electrodes 11a and 11b, and although a starting pulse is generated by the FEC 16, the lamp does not light up. In such a situation, the lamp will not light up until the thermal switch 15a on the auxiliary electrode side is turned on, and the starting pulse will continue to be generated, causing problems such as adverse effects on the circuit components and early deterioration of the FEC itself. arise.

In particular, the above-mentioned problem becomes more pronounced when an FEC with large pulse energy is used for a metal halide lamp.

The present invention has been made in view of the problems of the prior art, and its purpose is to provide a metal halide lamp that can prevent early deterioration of the FEC, ensure restart of the lamp, and is easy to manufacture. It's about doing.

[Means for Solving the Problems] In order to achieve the above object, the metal halide lamp according to the present invention has electrode films formed on both sides of a disk-shaped ferroelectric ceramic substrate as an FEC that constitutes a starter. The ferroelectric ceramic substrate is coated with ferroelectric crystallized glass except for the connecting portions of the lead wires thereto and the outer periphery of the ferroelectric ceramic substrate, and the lead wires are connected to the electrode film.

The thermal switch on the auxiliary electrode side and the thermal switch on the FEC side, which are incorporated into the lamp outer bulb together with the above-mentioned FEC, are each made of bimetal with substantially the same contact pressure, and the FEC side thermal switch is the auxiliary electrode side thermal switch. It is characterized by being installed at a position closer to the arc tube.

[Function] As mentioned above, in the FEC used in the metal halide lamp according to the present invention, the outer peripheral edge of the ferroelectric ceramic base is not covered with ferroelectric crystallized glass. The vibration of the base body is not suppressed, and a pulse voltage with a high peak value and a large energy/l is generated.

Furthermore, there is a time difference when the two thermal switches built into the lamp's outer bulb turn off.

In other words, when the lamp is cooled down and restarted, F
Since the EC side thermal switch is located in the high temperature range within the lamp, it turns on later than the auxiliary electrode side thermal switch, which is located in the low temperature range. As a result, after a state is reached in which discharge is possible between the auxiliary electrode and the main electrode, generation of a starting pulse by FEC is started, and the lamp is reliably restarted.

Therefore, even when using an FEC that can obtain a pulse voltage with a high peak value and large energy, it is necessary to prevent the adverse effects on the circuit components and the early deterioration of the FEC itself due to the pulse voltage being generated before the lamp is lit. I can do it.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

The circuit configuration of the metal halide lamp according to this example is the fifth one.
Since it is the same as that shown in the figure, the explanation will be omitted.

In this embodiment, the FECI 16 shown in FIG. 1 is used as the FEC shown in the above circuit.

This has barium titanate (BaTiOs) as its main component, the - part of the barium (Ba) of BaTiO3 is replaced with strontium (Sr), and part of the titanium (Ti) is replaced with zirconium (Zr) and hafnium (Hf). ) and added mineralizing agents of manganese (Mn) and chromium (Cr) to the powder, press-molded and fired to a diameter of 15.5 mm.
, a disk-shaped ferroelectric ceramic substrate 12 with a thickness of 065 cm.
1 is used. Then, on both sides of the base body 121, a diameter of 1
4.5 mm of silver metallization is applied to the electrode film 122a,
122b and covered with ferroelectric crystallized glass 123a and 123b except for the lead wire connection portions thereto and the peripheral edge of the ferroelectric ceramic substrate 121, and
A conductive adhesive 124a is applied to the electrode films 122a and 122b.
, 124b using the Riet wire 125a.

125b is connected. Note that the electrode film 122a122
It is appropriate to use a screen printing method or the like to form b and cover the ferroelectric crystallized glass 123a123b.

Furthermore, in this embodiment, a second thermal switch is used as the FEC side thermal switch and the auxiliary electrode side thermal switch shown in FIG.
Thermal switches 115a and 115b shown in the figure are used. The same figure (A) is the top view, and the same figure (B) is the side view.

The FEC side thermal switch 115a and the auxiliary electrode side thermal switch 115b are made of bimetal of the same material, the same size, and the same contact pressure.

This is to facilitate manufacturing and assembly.

And the two thermal switches 115a.

115b is a conductor 132a, 1 on an alumina substrate 131.
32b and one of the conductors, for example 132
A bimetal piece 133 is fixed to a, and the bimetal piece 13
A contact piece 134 provided at the tip of No. 3 is brought into contact with the other conductor 132b.

As shown in FIG. 3, the FEC side thermal switch 115b is installed closer to the arc tube 13 than the auxiliary electrode side thermal switch 115a, in other words, at a position where the temperature is higher. Note that 116 indicates FEC.

By doing this, the temperature difference within the lamp is used to turn on the FEC side thermal switch 115b later than the auxiliary electrode side thermal switch 115a when restarting the lamp.
can be activated.

FIG. 4 shows temperature changes at the positions where the FEC side thermal switch 115b and the auxiliary electrode side thermal switch 115a are installed after the lamps are turned off.

This figure shows the relationship between the time after a 400W metal halide lamp is turned on above the bare metal, turned off at 30° C. with no wind, and the temperature of both thermal switches 115a and 115b.

As is clear from the figure, on the base side of the lamp,
Due to the temperature difference in which the temperature is higher at a position closer to the arc tube 13, the FEC side thermal switch 115b placed at this position has a higher temperature than the auxiliary electrode side thermal switch 115a placed at a position farther from the arc tube 13. Temperature drop is delayed. Therefore, both thermal switches 115a, 115
Since the contact pressures b are the same, the auxiliary electrode side thermal switch 115a whose temperature drops to the predetermined temperature first turns on earlier.

As a result, first, after a state in which discharge is possible between the main electrode 11b and the auxiliary electrode 12 is achieved, the FEC side thermal switch 115b is turned on and a pulse necessary for starting the lamp is generated, so that the main electrode 11b and the auxiliary electrode 12 are connected to each other. Discharge starts between the auxiliary electrode 12, and then the discharge moves between the main electrodes 11a and llb, so that the lamp can be reliably lit.

In addition, unnecessary pulse generation in the FEC116 can be prevented, so even when using FEC, which can obtain pulse voltages with high peak values and large energy, pulse voltages are generated without the lamp lighting up and have an adverse effect on circuit components. In addition, it is possible to prevent a situation in which the FEC itself deteriorates prematurely.

[Effects of the Invention] As explained above, according to the metal halide lamp according to the present invention, the FEC constituting the starter is one in which the peripheral edge of the ferroelectric ceramic base is not covered with ferroelectric crystallized glass. Since it is used, a pulse voltage with high energy is generated.

Furthermore, as a thermal switch to be housed in the lamp outer bulb together with the FEC, an FEC-side thermal switch and an auxiliary electrode-side thermal switch, each made of bimetal with the same contact pressure, are installed on the base side of the lamp.
Since the C-side thermal switch is installed closer to the arc tube, there is a time difference between the 0N10FF operation of the two, and the starting pulse is applied while a discharge is occurring between the starting auxiliary electrode and the main electrode, ensuring reliable operation. It is possible to restart the lamp.

Further, since a pulse voltage is not generated while the lamp is not lit, it is possible to prevent adverse effects on circuit components and early deterioration of the FEC itself.

Furthermore, since both thermal switches are the same component, manufacturing can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of an FEC used in a metal halide lamp according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of two thermal switches of a metal halide lamp according to an embodiment of the present invention. The same figure (A) is a top view, the same figure (
B) is a side view, FIG. 3 is an explanatory diagram of a metal halide lamp which is an embodiment of the present invention, and FIG. 4 is a diagram after the lamp is turned off at each position where the FEC side thermal switch and the auxiliary electrode side thermal switch are installed. FIG. 5 is a circuit diagram of a conventional metal halide lamp, and FIG. 6 is a schematic sectional view of a conventional FEC. 63°...electrode film, 123a. 23b...Ferroelectric crystallized glass.

Claims (1)

[Claims] (1) The auxiliary electrode of an arc tube has a pair of main electrodes and an auxiliary electrode provided close to at least one of the main electrodes, and the auxiliary electrode is formed by sealing metal halide together with mercury and a rare gas inside. A metal halide lamp that is connected to the other main electrode via a starting resistor and a thermal switch, and a starter that includes a nonlinear capacitor is connected between both main electrodes via a thermal switch, and these are housed within the lamp outer bulb. As the nonlinear capacitor of the starter, electrode films are formed on both sides of a disk-shaped ferroelectric ceramic substrate, and electrode films are formed on both sides of the disk-shaped ferroelectric ceramic substrate, and the electrode films are made of a ferroelectric ceramic substrate except for the lead wire connection portions thereto and the outer peripheral edge portion of the ferroelectric ceramic substrate. The thermal switch on the auxiliary electrode side and the thermal switch on the nonlinear capacitor side are each made of bimetal with substantially the same contact pressure. A metal halide lamp characterized in that the thermal switch on the nonlinear capacitor side is installed closer to the arc tube than the thermal switch on the auxiliary electrode side.