JP3525571B2 - High pressure discharge lamp - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to high pressure discharge lamps.

[0002]

2. Description of the Related Art Conventionally, as a high-pressure discharge lamp such as a high-pressure sodium lamp, as shown in FIG. 6, a starter 19 composed of a series body of a normally-closed thermal response switch 19a and a heating resistor 19b, and a normally-closed body. The parallel body of the heat-responsive switch 20 and the arc tube 1 is connected in parallel to form a parallel body, and the parallel body of the heating resistor 21 and the heat-responsive switch 22 is connected in parallel with the parallel body. It is known that the heat generating resistor 21 is arranged close to the normally closed heat responsive switch 20 (JP-A-7-105913).

With such a structure, when the arc tube 1 does not start for some reason, current continues to flow in the series body of the heat generating resistor 21 and the thermal response switch 22, and the heat generating resistor 2
1 generates heat, and the heat-responsive switch 20 arranged in the vicinity of the heat generating resistor 21 is opened by the heat of the heat generating resistor 21 and the pulse voltage can be stopped. At this time, the thermal responsive switch 22 is closed.

However, since the above-mentioned conventional high pressure discharge lamp does not permanently disable the starter 19 itself, when the application of the power supply voltage to the high pressure discharge lamp is stopped, the initial state is restored. The generation of the pulse voltage is repeated for a certain period each time the power is turned on. Further, in this conventional high-pressure discharge lamp, at the end of the life, the airtightness of the sealing portion of the arc tube 1 is lowered, and the starting rare gas in the arc tube 1 flows out into the outer tube 9 which is a vacuum. As the phenomenon occurs, the pressure of the rare gas in the arc tube 1 decreases, and the temperature of the arc tube 1 decreases due to the convection and heat conduction by the rare gas in the outer tube 9, so that the lamp voltage falls below the normal value. Will end up. The lamp voltage further decreases as the outflow of the rare gas from the arc tube 1 results in an increase in the lamp current, and this increase in the lamp current causes an excessive temperature rise in the ballast 10. In such a state, after turning off the power switch to cool the high pressure discharge lamp and turning on the power switch again, the arc tube 1
Discharge restarts, so that if the high-pressure discharge lamp thus formed is left unattended, the temperature of the winding inside the ballast 10 rises abnormally, which may shorten the life of the ballast 10. .

[0005]

As a solution to this problem, as shown in FIG. 7, a normally closed thermal response switch 1 is provided.
Starter 19 comprising a series body of 9a and heating resistor 19b
And a series body of a circuit breaker 23 for shutting off the starter 19 when an overcurrent flows, is connected in parallel with the arc tube 1, and the terminal 24 on the circuit breaker 23 side of the starter 19 faces each other. It is known that the electric conductor 25 is arranged in the vicinity of the electric conductor 25 (Japanese Patent Publication No. 3-63177).

In such a structure, when the starting rare gas leaks from the arc tube 1 and flows into the outer tube 9, when the pulse voltage is generated in the ballast 10 by the operation of the starter 19, the arc tube 1 is generated. Before the start of the discharge of the starter 19, a discharge occurs between the terminal 24 of the starter 19 and the conductor 25 of the opposite potential adjacent to the starter 19, and as a result, the short-circuit current of the ballast 10 flows to the circuit breaker 23 and 23 is cut off, the starter 19 becomes inoperable, and thereafter the high pressure discharge lamp does not start discharging.

However, in such a structure, although the airtightness of the sealed portion of the arc tube 1 is lowered, the pressure of the rare gas flowing out to the outer tube 9 is very low immediately after the outflow of the rare gas. In particular, when a glow starter that can obtain only a relatively low pulse voltage is used as the starter 19, there is a problem that the discharge in the outer tube cannot be reliably generated at a predetermined position.

According to the present invention, the starter can be reliably operated when the arc tube cannot be started for some reason or when the gas tightness of the arc tube sealing portion is lowered and the starting gas flows into the outer tube. Further, the present invention provides a high-pressure discharge lamp that is permanently inoperable and does not generate a pulse voltage.

[0009]

The high pressure discharge lamp of the present invention comprises an arc tube having a pair of electrodes at both ends in an outer tube having a vacuum inside, and an arc tube in which a rare gas for starting is sealed. A high-pressure discharge lamp having a starter for applying a pulse voltage between electrodes of an arc tube, wherein the starter comprises a glow starter and a heating resistor, and the starter is provided in parallel with the arc tube. and with a series of the first thermally actuated switch and the current fuse element normally closed is connected, the discharge gap unit in parallel to the starter is connected, before
The glow starter uses the heat of the heating resistor to generate the first heat.
Make sure that the response switch closes and breaks before opening.
Have a configuration .

[0010]

The high pressure discharge lamp of the present invention has a vacuum inside.
An outer tube has a pair of electrodes at both ends and
Between the arc tube enclosing a rare gas for movement and the electrode of the arc tube
High-voltage discharge with starter for applying pulsed voltage
A lamp, wherein the starter comprises a glow starter and a heating resistor.
An antibody, which is connected to the arc tube in parallel with the starter.
Series of closed first thermal switch and current fuse element
The body is connected and discharges in parallel with the starter
Gap means is connected, said discharge gap means
Has another pair of electrodes, and the another pair of electrodes is a ceramic
It has a structure provided on the dock base.

The high pressure discharge lamp of the present invention has a vacuum inside.
An outer tube has a pair of electrodes at both ends and
Between the arc tube enclosing a rare gas for movement and the electrode of the arc tube
High-voltage discharge with starter for applying pulsed voltage
A lamp, wherein the starter comprises a glow starter and a heating resistor.
An antibody, which is connected to the arc tube in parallel with the starter.
Series of closed first thermal switch and current fuse element
The body is connected and discharges in parallel with the starter
Gap means is connected, said discharge gap means
Has another pair of electrodes, and the another pair of electrodes is a ceramic
Of the other pair of electrodes that are provided on the
One is a tungsten fan connected in series with the starter.
It has a configuration that consists of an filament.

In the above structure, it is preferable that the tungsten filament as the electrode of the discharge gap means also has the function of the current fuse element.

In the above structure, it is preferable that at least one of the electrodes of the discharge gap means has an electron emitting substance.

In the above structure, it is preferable that the heating resistor of the starter is a ceramic-coated heater.

[0016]

[0017]

With this configuration, when the arc tube does not start for some reason, the voltage is continuously applied to the series body of the glow starter and the heating resistor, so that the glow starter is heated by the heating resistor and is always closed. Moreover, the valve is damaged when the hole is opened and the enclosed gas flows out. After that, the normally closed first thermoresponsive switch is opened by the heat of the heating resistor, the current flowing through the ballast is not changed, and the pulse voltage is stopped.

Further, when the rare gas for starting the arc tube flows out into the outer tube due to a decrease in the airtightness of the sealed portion of the arc tube, a discharge is generated between the discharge gaps through the rare gas flowing out into the outer tube, and stable. The short circuit current of the container flows through the discharge gap means to the current fuse element, and the current fuse element is blown. When the current fuse element is blown in this way, no current can flow through the starter, so the starter is permanently inoperable, and pulse voltage will not be generated even after the power is turned on again. .

Further, since the glow starter is constructed so that it is closed by the heat of the heat-generating resistor before the first heat-responsive switch is opened to cause damage, the starter is permanently inoperable. Can be in a state.

Further, since the discharge gap means has a pair of electrodes, and the pair of electrodes is provided on the ceramic substrate, it is possible to easily obtain a gap having a small gap, so that an accurate discharge gap can be obtained. Since it is obtained, it is possible to surely obtain the discharge in the discharge gap.

Further, since the pair of electrodes of the discharge gap means are provided on the ceramic substrate, and one of the electrodes is made of a tungsten filament connected in series with the starter, the current flowing through the starter causes Since the tungsten filament is heated to the red hot state, it is possible to surely cause the discharge in the electrode tube in the discharge gap at a relatively early stage when the rare gas starts to flow from the arc tube into the vacuum outer tube.

Further, since the tungsten filament serving as the electrode of the discharge gap means also functions as the current fuse element, when the short circuit current of the ballast flows through this filament due to discharge in the discharge gap, the tungsten filament is discharged. The high-pressure discharge lamp can be blown out and the high-pressure discharge lamp cannot be started, and the number of parts can be reduced.

Further, since at least one of the electrodes of the discharge gap means has an electron emissive substance, it is possible to further ensure the start of discharge in the discharge gap.

Further, since the heating resistor of the starter is made of a ceramic-coated heater, the heating resistor can be downsized and does not interfere with light emission when the lamp is turned on.

[0025]

[0026]

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

The high pressure sodium lamp with a built-in starter according to the first embodiment of the present invention shown in FIG. 1 has a pair of electrodes at both ends, and sodium and mercury, as well as a rare gas for starting xenon and the like are contained therein. It has an arc tube 1 made of a translucent alumina ceramic filled with gas. The arc tube 1 is connected in parallel with a series body of a starter 2, a normally closed first thermoresponsive switch 3 and a current fuse element 4. The starter 2 is composed of a glow starter 2a and a heating resistor 2b for limiting a current flowing through the glow starter 2a, which are connected in series. The heating resistor 2b is the glow starter 2
It is provided close to a. First thermal switch 3
Is for cutting off the current supply to the starter 2 by opening the circuit by radiation heat from the arc tube 1 during stable lighting of the high pressure discharge lamp. The first thermoresponsive switch 3 is configured to open when the heat of the heating resistor 2b generated when the arc tube 1 cannot be started exceeds the bulb heat resistant temperature of the glow starter 2a. The current fuse element 4 is constructed so that it blows out instantly when a current significantly larger than the current value determined by the heating resistor 2b flows. A discharge gap 5 having a pair of electrodes 5a and 5b, which will be described later, is connected in parallel with the starter 2. The discharge gap 5 has one electrode 5a connected to one end of the arc tube 1 and one end of the starter 2. And the other electrode 5b of the discharge gap 5 is connected to the connection point between the other end of the starter 2 and one end of the current fuse element 4, respectively.

The first thermoresponsive switch 3 does not necessarily have to be connected to the position shown in FIG. 1, but may be connected to an appropriate position such as between the starter 2 and the current fuse element 4. In this case, the discharge gap 5 may be connected in parallel with the series body of the starter 2 and the first thermoresponsive switch 3. The proximity conductor 8 is arranged in contact with the outer surface of the arc tube 1, and is connected to one electrode of the arc tube 1 via the second heat-responsive switch 7. The second heat-responsive switch 7 is for opening the circuit due to radiant heat from the arc tube 1 during stable lighting of the high-pressure discharge lamp so that no potential is applied to the adjacent conductor 8. 9 is an outer tube, the inside of which is maintained at a high vacuum.
Further, 10 is a ballast, and 11 is an AC power source, respectively.

The discharge gap 5, which is the discharge gap means shown in FIG. 2, has a pair of electrodes 5a and 5b on a ceramic substrate.
The pair of electrodes 5a and 5b are provided by baking on a ceramic substrate. In addition, 12 and 13 have shown the terminal of the electrodes 5a and 5b of the discharge gap 5, respectively.

When a power source voltage is applied to the high-pressure sodium lamp configured as shown in FIG. 1 through the ballast 10, the glow starter 2a of the starter 2 starts the opening / closing operation and a pulse voltage is applied between the terminals of the ballast 10. Occur. When the arc tube 1 starts to discharge due to this pulse voltage, the arc tube voltage drops, so the glow starter 2a stops operating in the open circuit state, and the current flowing to the starter 2 also stops. After that, the arc tube 1 starts normally and shifts to a stable state. The current flowing through the starter 2 at this time is determined by the impedance of the ballast 10 and the resistance value of the heating resistor 2b, and the fusing current of the current fuse element 4 is set sufficiently higher than that.
The current fuse element 4 is not blown by the current at this time.

In a state where the arc tube 1 operates normally, the time from application of the power supply voltage to the start of discharge of the arc tube 1 is at most several seconds, and the heating resistor 2b during this period. The glow starter 2a does not reach the closed circuit temperature even if it is heated by. After that, when the temperature of the arc tube 1 rises, the heat causes the first thermoresponsive switch 3 to open. Therefore, the starter 2 is shut off during stable lighting of the high-pressure discharge lamp, and the current is maintained in a non-current state.

Should the starting voltage of the arc tube 1 increase significantly at the end of the life of the high pressure discharge lamp, or a part of the current supply line to the arc tube 1 will be cut off due to a mechanical shock from the outside. Then, when the arc tube 1 is in a non-startable state, naturally, the arc tube 1 does not start discharging even if the power supply voltage is applied. In this case, by continuing to apply the power supply voltage, the glow starter 2a continues to open and close, and the current continues to flow intermittently in the starter 2.
b heats up and its temperature rises. The temperature of the heating resistor 2b heats the glow starter 2a provided in the vicinity of the heating resistor 2b, and the glow starter 2a is heated.
When the closing temperature of the contacts in a is exceeded, the glow starter 2a is normally closed. This eliminates the abrupt change in current and thus stops the generation of pulse voltage. After that, by applying a voltage to the heating resistor 2b, the heating resistor 2b
The heating of the glow starter 2a from b continues. When the temperature of the glow starter 2a exceeds the heat resistant temperature of the bulb of the glow starter 2a, the valve of the glow starter 2a has a hole, and the first thermal response switch 3 opens. Then, since the enclosed gas in the glow starter 2a is discharged, the pulse voltage is never generated in the glow starter 2a even if the temperature of the glow starter 2a is lowered and the bimetal contact in the glow starter 2a is opened.

Further, when the rare gas for starting in the arc tube 1 flows into the vacuum outer tube 9 due to a decrease in the airtightness of the sealed portion of the arc tube 1 at the end of the life of the high pressure discharge lamp or the like. Due to the presence of the noble gas that has flowed out, a discharge occurs between the electrodes 5a and 5b of the discharge gap 5 due to the pulse voltage at the time of starting the high-pressure discharge lamp, and the short-circuit current of the ballast 10 passes through the discharge gap 5 and becomes a current. It flows into the fuse element 4 and the current fuse element 4 is blown. Current fuse element 4
When the blowout occurs, no current can flow through the starter 2, so that the starter 2 becomes permanently inoperable and the high pressure discharge lamp will not start. Therefore, it is possible to prevent a phenomenon in which the temperature of the ballast 10 excessively rises due to an increase in the lamp current accompanying the operation of the high-pressure discharge lamp in the state where the lamp voltage is low.

A high pressure sodium lamp with a built-in starter, which is a second embodiment of the present invention shown in FIG. 3, uses a tungsten filament 6 as one of the electrodes 5b of the discharge gap 5, and the other structure is as described above. It is similar to the embodiment.
The tungsten filament 6 is connected in series to the starter 2 and is heated to a red heat state by the electric current flowing through the starter 2. With this configuration, the arc tube 1
When the starting rare gas starts to flow out from the arc tube 1 into the vacuum outer tube 9 due to a decrease in the airtightness of the sealed portion of the battery, the discharge is generated between the electrodes 5a and 5b of the discharge gap 5 at a relatively early stage. And the current fuse element 4 is blown to make the high-pressure discharge lamp inoperable again.

In the high pressure sodium lamp with a built-in starter according to the third embodiment of the present invention shown in FIG. 4, the tungsten filament 6 as one electrode 5b of the discharge gap 5 in FIG. 3 also functions as a current fuse element. 1 is unnecessary, and the current fuse element 4 shown in FIG. 1 is not necessary, and other configurations are the same as those in the above-described respective embodiments. In this embodiment, a discharge occurs in the discharge gap 5 and the ballast 1
When the short-circuit current of 0 flows into the tungsten filament 6a which also functions as a current fuse element, the tungsten filament 6a is fused.

Further, in any of the configurations of the above-mentioned respective embodiments, the discharge initiation in the discharge gap 5 is performed by applying or containing an electron emissive material such as a metal oxide to at least one electrode of the discharge gap 5. Can be made more reliable.

A normal carbon film resistor may be used as the heating resistor 2b in each of the above embodiments. Further, as the heating resistor 2b, a flat plate-shaped ceramic coating heater may be used as shown in FIG. This ceramic coating heater is unitized by integrally mounting on its surface one electrode 5a of the discharge gap 5 and the other electrode 5b made of the tungsten filament 6 (or 6a). Further, as shown in FIG. 5, necessary terminals are provided on the surface of the ceramic coating heater.
Is a terminal of the heating resistor 2b, 16 is a terminal of one electrode 5a of the discharge gap 5, and 17 is a tungsten filament 6 (or 6a) which becomes the other electrode 5b of the discharge gap 5.
1 is a terminal for connecting one end to the first thermoresponsive switch 3, and 18 is a mounting terminal for holding the entire unit in an appropriate position inside the outer tube 9 of the high pressure discharge lamp.

Next, 220 having the circuit configuration shown in FIG.
The high-pressure sodium lamp with a built-in starter of W will be described.

The arc tube 1 has an outer diameter of 9 mm and an electrode distance of 58 m.
m of xenon as a rare gas for starting at a pressure of about 27 kPa. As the heating resistor 2b connected in series to the glow starter 2a, a square having a side of 25 mm has a resistance value at room temperature and a saturation temperature of about 650 ° C.
Ceramic coated heaters of about 100Ω and 500Ω were used, respectively. Operating temperature of bimetal contact is about 100
Glow starter 2 with a valve heat resistant temperature of about 550 ° C
The ceramic coating heater a was brought into contact with a, and the operating temperature of the first thermoresponsive switch 3 was set to about 200 ° C. Furthermore the first
The heat-responsive switch 3 is arranged so as to be operated by the heat from the ceramic coating heater when the arc tube 1 cannot be started and the temperature exceeds the bulb heat resistant temperature of the glow starter 2a. One electrode 5 of the discharge gap 5
As a, a tungsten coil electrode generally used in a high-pressure discharge lamp was coated with a mixed oxide of barium, calcium, and yttrium as an electron emissive material and fired. As the other electrode 5b of the discharge gap 5, a tungsten wire having a diameter of 95 μm is used as the mandrel diameter 5
Effective length 18 mm wound with 80 μm and pitch 130 μm
The tungsten filament 6a was used, the distance from the electrode 5a was set to 5 mm, and the tungsten filament 6a was attached as shown in FIG.

When the high-pressure sodium lamp thus constructed was connected to a 200 V AC power source via a 250 W high-pressure mercury lamp ballast, the arc tube 1 started normally and went into a stable state through the process described above. Next, in order to perform an experiment in a state in which the arc tube 1 cannot be started, after turning off the high pressure discharge lamp and cooling the laser tube, the arc tube is used inside the outer tube 9 without destroying the outer tube 9. The current supply line to No. 1 was disconnected, and the arc tube 1 was put into a state in which it could not be started.

When the power supply voltage is applied in this state, the current continues to flow in the starter 2 and the temperature of the ceramic coating heater as the heating resistor 2b rises rapidly, and heating from the ceramic coating heater to the glow starter 2a continues. Then, the bimetal contact in the glow starter 2a closed over the operating temperature, and the generation of the pulse voltage stopped. When the temperature of the glow starter 2a exceeds the heat resistant temperature of the valve of the glow starter 2a, a hole is opened in the valve of the glow starter 2a and it is damaged, and then the first thermoresponsive switch 3 is opened. As a result, the starter 2 was cut off, no current flowed through the starter 2, and the temperature of the ceramic-coated heater dropped. Then, the first heat-responsive switch 3 was closed, but the glow starter 2a was damaged, so even if the power supply voltage was applied again, the pulse voltage was never generated again.

Next, in order to realize a state in which xenon as a rare gas for starting flows out from the arc tube 1 into the outer tube 9 due to a decrease in the airtightness of the sealed portion of the arc tube 1, the xenon is also formed with the arc tube 1. An experimental high-pressure discharge lamp was prepared in which the pseudo arc tubes with different filling pressures were held inside the outer tube 9. After the completion of this lamp, a hole was made in the tube wall of the pseudo arc tube by the above-mentioned method with a laser to make xenon. It was allowed to flow into the outer tube 9.

When a power supply voltage is applied to such a high-pressure discharge lamp, the calculated xenon pressure in the outer tube 9 is 10 Pa.
Under the conditions described above, the discharge occurred in the discharge gap 5 without the discharge of the arc tube 1 starting, and the tungsten filament 6a which also serves as a current fuse element was blown.

In each of the above embodiments, the high pressure sodium lamp was described, but the same effect can be obtained also in a metal halide lamp in which a rare gas such as argon is enclosed in the arc tube together with mercury and a metal halide.

[0045]

As described above, the present invention is
At the end of the life of the discharge lamp, the starting voltage of the arc tube rises significantly, or a part of the current supply line to the arc tube is cut by a mechanical shock from the outside, and the arc tube becomes inoperative. Not only when the starting gas inside the arc tube flows out into the outer tube due to a decrease in the airtightness of the arc tube sealing part, the starter operation is promptly and surely stopped, and the pulse is permanently applied. It is possible to provide a high-pressure discharge lamp that can stop the generation of a voltage and can prevent the insulation of the starter and the lighting circuit wiring from being lowered and the abnormal temperature rise of the ballast to be prevented.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a high pressure discharge lamp which is a first embodiment of the present invention.

FIG. 2 is a diagram showing a discharge gap as well.

FIG. 3 is a circuit diagram of a high pressure discharge lamp which is a second embodiment of the present invention.

FIG. 4 is a circuit diagram of a high pressure discharge lamp which is a third embodiment of the present invention.

FIG. 5 is a view showing a unit of parts in the high pressure discharge lamp of the present invention.

FIG. 6 is a circuit diagram of a conventional high pressure discharge lamp.

FIG. 7 is a circuit diagram of a conventional high pressure discharge lamp.

[Explanation of symbols]

1 arc tube 2 starter 2a glow starter 2b Heating resistor 3 First thermal switch 4 Current fuse element 5 discharge gap 6 Tungsten filament 7 Second thermal switch 9 outer tube

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hong Gion 1-1 Sachimachi, Takatsuki City, Osaka Prefecture Matsushita Electronics Industrial Co., Ltd. (56) Reference JP 5-325904 (JP, A) JP JP 7-153432 (JP, A) JP-A-7-111147 (JP, A) JP-A-7-105913 (JP, A) Patent 3328114 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01J 61/50 H01J 61/54 H01J 61/56

Claims (6)

(57) [Claims] 1. A pulse voltage is applied between an arc tube having a pair of electrodes at both ends, and a rare gas for starting sealed inside, and an electrode of the arc tube. And a starter comprising a glow starter and a heating resistor, the starter and a normally closed first thermal response switch and a current in parallel with the arc tube. A series body with a fuse element is connected, and a discharge gap means is connected in parallel with the starter.
And the glow starter is heated by the heat generated by the heating resistor.
The first thermal switch closed before opening, resulting in damage.
High-pressure discharge lamp characterized in that it is configured as . 2. A pair of tubes at both ends inside an outer tube having a vacuum inside.
Equipped with the electrode of and emitting a rare gas for starting inside.
To apply a pulse voltage between the tube and the electrodes of the arc tube
A high-pressure discharge lamp having a starter of
The lamp consists of a glow starter and a heating resistor,
A first heat-actuated switch that is normally closed with the starter in parallel with the pipe.
And a series body of current fuse element is connected
, The discharge gap means is connected in parallel with the starter.
And the discharge gap means has another pair of electrodes,
High圧放electric lamp you characterized in that said further pair of electrodes are found provided on ceramic substrate. 3. An outer tube having a vacuum inside, and a pair at both ends.
Equipped with the electrode of and emitting a rare gas for starting inside.
To apply a pulse voltage between the tube and the electrodes of the arc tube
A high-pressure discharge lamp having a starter of
The lamp consists of a glow starter and a heating resistor,
A first heat-actuated switch that is normally closed with the starter in parallel with the pipe.
And a series body of current fuse element is connected
, The discharge gap means is connected in parallel with the starter.
And the discharge gap means has another pair of electrodes,
The other pair of electrodes is provided on the ceramic substrate.
And one of the other pair of electrodes is directly connected to the starter.
High圧放electric lamp characterized in that it consists of connecting tungsten filament in the column. 4. The high pressure discharge lamp according to claim 3, wherein the tungsten filament as an electrode of the discharge gap means also functions as the current fuse element. 5. A high pressure discharge lamp according to any one of claims 1 to 4 wherein at least one of the electrodes of the discharge gap means and having an electron emitting material. 6. A high-pressure discharge lamp according to any one of claims 1 to 5 heating resistor of the starter is characterized by comprising the ceramic coating heater.