JP2002151007A - High-pressure discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To let generation of pulse voltage stop in case a high-pressure discharge lamp does not start due to some cause. SOLUTION: A series circuit of a starter 2 composed of a glow starter 7 and a resistive heat generating body 8 and a heat actuating switch 3 in parallel with a light emitting tube 1, and in case the high-pressure discharge lamp does not start, the resistance exothermic body 8 exotherms, the glow starter 7 closes the circuit by this heat, a rapid change of current continuing to flow to a ballast 30 is eliminated, and the generation of the pulse voltage is made to stop.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-pressure discharge lamp.

[0002]

2. Description of the Related Art Conventionally, in a high-pressure discharge lamp such as a high-pressure sodium lamp, a starting rare gas such as xenon gas is sealed in an arc tube, and the efficiency is improved by increasing the sealing pressure. Since the starting voltage of the high-pressure discharge lamp is high, for example, as shown in FIG. 4, a starter 14 composed of a series circuit of a bimetal switch 12 and a heating resistor 13 is connected in parallel with the arc tube 1, and the outer tube 4 Housed within. In the starter 14, the bimetal switch 12 is heated by the heating resistor 13 glowing red, and the current flowing through the ballast 10 is rapidly cut off by opening the bimetal switch 12, thereby generating a pulse voltage.

[0003]

In the above-mentioned conventional high-pressure discharge lamp, the starting voltage of the luminous tube is significantly increased at the end of the life of the discharge lamp, or a mechanical shock from the outside may cause the luminous tube to fail. When the connection is broken, the arc tube does not start, the application of the power supply voltage to the starting unit continues, and the pulse voltage continues to be generated. If the power switch is turned on in this state, the life of the ballast may be shortened due to the continuous application of the pulse voltage, or the insulation of the wiring between the ballast and the lamp may be reduced.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and provides a high-safety high-pressure discharge lamp which does not generate a pulse voltage when the arc tube does not start for some reason. It is intended to be.

[0005]

In order to achieve the above object, a high-pressure discharge lamp according to the present invention comprises a series circuit including a glow starter, a resistance heating element and a normally-closed thermoresponsive switch connected in parallel to an arc tube. When the arc tube is housed in the outer tube and the arc tube is inoperative, the contact of the glow starter is closed by the heat of the resistance heating element, and the thermoresponsive switch is also closed, and the switching temperature of the thermoresponsive switch is closed. Is 100 ~
The glow starter is installed at a position within a range of 350 ° C., where the temperature of the arc tube is inoperable and the temperature becomes 150 ° C. or higher by heat from the resistance heating element.

In the above structure, it is preferable that the resistance heating element is a ceramic heater.

In the above structure, the resistance heating element preferably has a cold resistance of 100Ω to 500Ω.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A high-pressure discharge lamp according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a circuit configuration of the high-pressure discharge lamp of the first embodiment, and FIG. 2 is a front view showing a configuration of a main part of the high-pressure discharge lamp.

As shown in FIG. 1, in the high-pressure discharge lamp of the present invention, a series circuit composed of a starter 2 and a thermally responsive switch 3 is connected in parallel between both electrodes 1a and 1b of an arc tube 1. It is housed in the outer tube 4. When the high-pressure discharge lamp is a high-pressure sodium lamp, the inside of the outer tube 4 is generally maintained at a high vacuum. On the other hand, when the high-pressure discharge lamp is a metal halide lamp, the outer tube 4 may be filled with an inert gas such as nitrogen. One electrode 1 a of the arc tube 1 is connected to a starting auxiliary conductor 5 via a starting auxiliary heat responsive switch 6. The starting auxiliary conductor 5 is wound along the outer surface of the arc tube 1 and is provided near the arc tube 1. Both electrodes 1 a and 1 b of the arc tube 1 are connected to a power supply 11 via a ballast 10.

The starter 2 comprises a series circuit of a glow starter 7 and a resistance heating element 8 for limiting a current flowing through the glow starter 7. The thermally responsive switch 3 stops the supply of current to the starter 2 after the discharge of the arc tube 1 starts. The return time of the thermally responsive switch 3 is longer than the return time of the start-assisting thermally responsive switch 6 to ensure lighting when the lamp is restarted, that is, when the current to the lamp is cut off and turned on again. It is set to be. FIG. 2 shows the arrangement of the starter 2 and the thermoresponsive switch 3. As shown in FIG. 2, the glow starter 7 is in contact with the resistance heating element 8, and the thermally responsive switch 3 is disposed above the glow starter 7 so as not to receive heat from the resistance heating element 8.

Next, FIG. 3 shows an example of a configuration in which the arc tube 1 having the auxiliary electrode is used. The configuration example shown in FIG. 1 is different from the configuration example shown in FIG. 1 in that the starting auxiliary conductor 5 and the starting auxiliary thermal responsive switch 6 are not provided, and the resistor 9 for suppressing the current to the auxiliary electrode is the electrode 1 b of the arc tube 1. And a point provided between the starter 2 and the connection point of the thermoresponsive switch 3.

Next, the high-pressure sodium lamp of the present invention is
The operation in the case of lighting using the inductive ballast 10 and the power supply 11 will be described. First, when a power supply voltage is applied to the high-pressure sodium lamp having any one of the above configurations via the ballast 10, a current flows through the starter 2. When the glow starter 7 of the starter 2 performs the opening / closing operation, a sudden change in the current flowing through the ballast 10 occurs, and a pulse voltage is induced in the ballast 10. Then, the discharge of the arc tube 1 is started by the pulse voltage and the starting assist effect of the starting assist conductor 5 provided on the outer surface of the arc tube 1. After the start of the discharge, the heat responsive switch 6 for starting assistance and the heat responsive switch 3 are opened by the heat from the arc tube 1,
The voltage application to the starting auxiliary conductor 5 and the starter 2 is stopped.

In a state where the arc tube 1 operates normally, the time from the application of the power supply voltage to the start of the discharge of the arc tube 1 is a few seconds at the longest. Glow starter 7 does not reach the closed circuit temperature. However, at the end of the life of the lamp, the starting voltage of the arc tube 1 increases significantly, or a part of the current supply line to the arc tube 1 is cut off by an external mechanical shock. When the engine cannot be started, the arc tube 1 does not start discharging even when the power supply voltage is applied, and the glow starter 7 continues to open and close.
The current continues to flow intermittently in the circuit of the starter 2, and the temperature of the resistance heating element 8 rises. Thereby, the glow starter 7 is heated. When the temperature of the glow starter exceeds the closing temperature of the contact provided on the glow starter 7, the glow starter 7 is always closed. Therefore, there is no sudden change in the current, and the generation of the pulse voltage by the ballast 10 stops.

[0014]

Next, specific examples of the present invention will be described. The circuit configuration shown in FIG. 1 is arranged as shown in FIG.
A 0 W high pressure sodium lamp was made. The dimensions of the arc tube 1 are 9 mm in outer diameter and 58 mm between electrodes. The closing temperature of the contact of the glow starter 7 is about 100 ° C., and the heat-resistant temperature of the valve is about 550 ° C. As the resistance heating element 8 connected in series to the glow starter 7, a square ceramic heater having a side of 30 mm was used. The resistance value of the ceramic heater at room temperature was about 100Ω, and the resistance value at a saturation temperature of about 500 ° C. was about 500Ω. A bimetal switch having an open circuit temperature of about 200 ° C. was used as the thermally responsive switch 3 connected in series to the starter 2 composed of these components.

Here, the cold resistance value of the resistance heating element 8 is set to about 10
However, if the cold resistance value is 100Ω or less, the current flowing through the starter 2 is large.
Deteriorates very quickly. On the other hand, if it is 500Ω or more,
Since the current flowing through the starter 2 is small, a pulse voltage sufficient to start the arc tube 1 cannot be obtained. for that reason,
In practice, a range of about 100 to 500Ω is appropriate.

Furthermore, although the open circuit temperature of the thermoresponsive switch 3 is set to about 200 ° C., the ambient temperature when the lamp is actually used is at most about 50 ° C. Must be closed.
Further, the thermally responsive switch 3 must be arranged so as not to hinder the light emission when the lamp is turned on. Furthermore, in order to stop the current supply to the starter 2 when the lamp is turned on, it is necessary to open the thermal responsive switch 3 reliably.
Taking these into account, practically about 100-350 ° C
It is enough if it is within the range.

By increasing the interval between the contacts of the glow starter 7, the operating temperature of the contacts can be increased and a high pulse voltage can be obtained. However, accompanying this, the operating voltage of the glow starter 7 increases and the performance decreases. Therefore, the operating temperature of the contact is reduced to about 10
It is 0 ° C. In order to surely close the contact, the glow starter 7 may be installed at a position where the temperature becomes 150 ° C. or higher.

When the high-pressure sodium lamp manufactured according to the above specification was connected to a 200 V AC power supply through a 250 W high-pressure mercury lamp ballast, the light was emitted within a few seconds after the power was turned on through the above-described process. The tube 1 started normally and shifted to a stable lighting state. Next, in order to perform an experiment in a state where the arc tube 1 cannot be started, after the lamp is turned off and cooled, a laser beam is used to break the arc tube in the outer tube 4 without breaking the outer tube 4. Then, the current supply line to the arc tube 1 was cut off, and the arc tube 1 was set in a state where it could not be started. When the power supply voltage was applied in this state, the current continued to flow through the starter 2, and the temperature of the ceramic heater rapidly increased. After about 30 seconds, the contact of the glow starter 7 was closed and the generation of the pulse voltage was stopped. That is, it was confirmed that the high-pressure discharge lamp of the present invention operated as intended.

[0019]

As described above, according to the present invention,
In the outer tube, together with the arc tube, a series body including a glow starter, a resistance heating element and a normally-closed thermoresponsive switch was connected in parallel to the arc tube and housed. Even if the voltage rises significantly or the arc tube becomes unable to start due to an accident such as a part of the current supply line to the arc tube being cut off by an external mechanical shock, the heat generated by the resistance heating element Closes the glow starter,
In addition, since the thermally responsive switch is also closed, the current does not suddenly change, and the generation of the pulse voltage by the ballast stops. As a result, it is possible to prevent insulation deterioration of the ballast and the lighting circuit wiring, and to obtain a high-safety high-pressure discharge lamp.

The glow starter is closed by setting the switching temperature of the thermoresponsive switch within the range of 100 to 350 ° C. and installing the glow starter at a position where the temperature becomes 150 ° C. or more by heat from the resistance heating element. At this time, the thermally responsive switch can be reliably closed. Also,
Since the current supply to the starter is stopped when the lamp is turned on, the thermally responsive switch can be reliably opened.

By using a ceramic heater as the resistance heating element, a resistance value of about 100Ω at room temperature and about 500Ω at a saturation temperature of about 500 ° C. can be obtained. Further, the resistance heating element can be reduced in size, and does not hinder light emission when the lamp is turned on. Further, the cold resistance value of the resistance heating element is set to 10
By setting the range of 0 to 500Ω, a pulse voltage sufficient to start the arc tube can be obtained, and the glow starter does not deteriorate rapidly. Further, by disposing the glow starter between the resistance heating element and the thermoresponsive switch, the glow starter blocks heat from the resistance heating element, so that the thermoresponsive switch is less likely to receive heat.
A normally closed state can be maintained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a circuit configuration of an embodiment of a high-pressure discharge lamp of the present invention.

FIG. 2 is a front view showing an arrangement of main parts in one embodiment of the high-pressure discharge lamp of the present invention.

FIG. 3 is a schematic diagram showing a circuit configuration of another embodiment of the high-pressure discharge lamp of the present invention.

FIG. 4 is a schematic diagram showing a circuit configuration of a conventional high-pressure discharge lamp.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Arc tube 2 Starter 3 Thermal response switch 4 Outer tube 5 Starter auxiliary conductor 6 Startup assistance thermal response switch 7 Glow starter 8 Resistance heating element 9 Resistor 10 Ballast 11 Power supply 12 Bimetal switch 13 Heating resistor 14 Starter

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 41/18 310 F21Y 101: 00 // F21Y 101: 00 F21S 5/00 A (72) Inventor Mii Akira 1006 Kadoma, Kazuma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. BC03 BC33 BD09 BD12 BD22 CA32 CA37 EA02 5C039 BB04 BB07 BB23

Claims (3)

[Claims] 1. A series circuit including a glow starter, a resistance heating element and a normally-closed thermally responsive switch is connected in parallel to an arc tube and housed in an outer tube. A high pressure discharge lamp in which a contact of the glow starter is closed by heat of a body and the thermoresponsive switch is also closed, wherein a switching temperature of the thermoresponsive switch is in a range of 100 to 350 ° C., and the light emission is performed. A high-pressure discharge lamp in which the glow starter is installed at a position where the temperature becomes 150 ° C. or more due to heat from the resistance heating element when the tube is inoperative. 2. The high pressure discharge lamp according to claim 1, wherein said resistance heating element is a ceramic heater. 3. The resistance heating element has a cold resistance value of 100Ω or more.
3. The high-pressure discharge lamp according to claim 1, which has a resistance of 500Ω.