JPH06275239A - Alternately lighted discharge lamp - Google Patents

Abstract

PURPOSE:To extend the lives of high-pressure discharge lamps for general illumination and reduce the cost for lamp replacement. CONSTITUTION:An outer tube 6 is provided with two light emitting tubes 1, 2 electrically connected in parallel and a selector switch 3 for switching the connection of proximity conductors 1a, 2a or auxiliary electrodes of the light emitting tubes 1, 2 in turn at each excitation. Lives of lamps are doubled, and the cost for lamp replacement is reduced in half.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alternating lighting discharge lamp, and more specifically, a plurality of arc tubes such as mercury lamps, metal halide lamps and high pressure sodium lamps are housed in an outer tube and the arc tubes are switched alternately. It relates to the improvement of the alternating lighting type discharge lamp used as

[0002]

2. Description of the Related Art Conventionally, as a discharge lamp such as a high-pressure sodium lamp or a metal halide lamp, US Pat. S. P. No. 4,287,454, or a discharge lamp in which two arc tubes are connected in parallel in one outer tube and is housed, as described in Japanese Patent Publication No. Sho 56-93260. There is. In this discharge lamp, only one of the arc tubes is turned on.If the discharge lamp is once turned off and then restarted immediately, it is possible to turn on the other arc tube that was not turned on until then. . While the normal high pressure discharge lamp in which one arc tube contains one arc tube requires a restart time of about 15 minutes, the above lamp has an advantage of immediate restart.

[0003]

The important characteristics required for a discharge lamp are longevity and economic efficiency, in addition to brightness and shortening of starting time. The above-mentioned discharge lamp having two arc tubes, which is conventionally known, has two
Since the control of which one of the individual arc tubes is to be turned on is not performed, when the normal blinking is repeated, the cumulative lighting times of the respective arc tubes are not always equal and may be biased to one side. Further, the discharge lamp of this type has a high lamp voltage at the end of its life, and often goes out in a few minutes after lighting. In this case, only the arc tube which has begun to extinguish repeats blinking every 2-3 minutes, and the other arc tube having the remaining life cannot be lit. That is, the lamp is at the end of its life. Therefore, the life is not doubled even if two arc tubes are stored. In order to solve such a problem, there has been proposed a technique in which a special ballast that performs alternate lighting control is provided in the power supply circuit outside the discharge lamp, but compared with a ballast having a single arc tube. It is expensive and has the disadvantage that it cannot be used with existing, less expensive exclusive ballasts or ballasts for mercury lamps.

Accordingly, it is an object of the present invention to provide a discharge lamp in which the cumulative lighting time life of each of the plurality of arc tubes is substantially equal. Another object of the present invention is to achieve the above object and to provide a highly economical high-voltage discharge that can be directly used without changing the lighting power supply equipment using the existing ballast for mercury lamps or the exclusive ballast for high-pressure discharge lamps. Is to provide a lamp.

[0005]

In order to achieve the above object, the present invention provides a switching control means in the outer tube for alternately lighting a plurality of arc tubes in the outer tube. As a case where a plurality of arc tubes are turned on alternately, when the number of arc tubes is three or more, switching is cyclically performed. A particularly preferable form is a discharge lamp which has two arc tubes and which is alternately lit from the viewpoints of the size of the discharge lamp, the simplicity of the switching control means, and the economical efficiency.

A preferred structure of the switching control means is realized by a switching means for switching the connection of the starting electrodes of each of the plurality of arc tubes each time the lamp is turned on (energized). As a starting electrode, in the case of mercury lamps and metal halide lamps, which are high-pressure discharge lamps, an auxiliary electrode that is provided close to the main electrode is used.In the case of high-pressure sodium lamps, the auxiliary electrode is arranged along the longitudinal direction of the arc tube. Then, a conductor (referred to as a proximity conductor) which is provided close to the arc tube and has one end connected to the main electrode of the arc tube is used. That is, the mercury lamp and the metal halide lamp are provided with a changeover switch that opens the auxiliary pole of one of the arc tubes when the one of the arc tubes is lit and closes the auxiliary pole of the other arc tube. The high-pressure sodium lamp is provided with a changeover switch that opens the proximity conductor of one of the arc tubes and closes the proximity conductor of the other arc tube when one of the arc tubes is lit. Another preferable configuration of the switching control means is a configuration in which the connection of the starting electrode is switched by a starter circuit having a resistance and a thermoresponsive switch.

[0007]

Since the alternate lighting discharge lamp of the present invention has the switching control means inside the outer tube, the power supply circuit including the external ballast should be the same as the conventional discharge lamp having a single arc tube. Therefore, the existing power supply equipment can be used as it is, which is extremely advantageous.

Regarding the life of the discharge lamp, when the plurality of arc tubes electrically connected in parallel is two, the arc tube to which the auxiliary electrode or the adjacent conductor is connected is turned on. When lit, the connection is switched to the auxiliary electrode or the adjacent conductor of the non-lit arc tube, and this state is maintained even when the arc tube is extinguished. Therefore, the next time the power is turned on, the arc tube that was previously turned off lights up. In this way, the two arc tubes are alternately turned on each time the power is supplied. Although the lighting time per one time varies, the lamp blinks several thousand times before the life of the lamp, and the cumulative lighting time of each arc tube becomes almost equal. Therefore, the life of this lamp is about twice as long as that of a discharge lamp having a single arc tube. Similarly, when the number of the plurality of arc tubes is three or more, each arc tube is lit cyclically each time the power is supplied, and the cumulative lighting time of each arc tube becomes substantially equal. Therefore, the life of the lamp of the present invention is about several times as long as that of a discharge lamp having one arc tube.

[0009]

【Example】

<Embodiment 1> FIG. 1 is a front view showing the construction of an embodiment of an alternating lighting discharge lamp according to the present invention. In the figure, both 1 and 2 are 360 W high pressure sodium lamp arc tubes. The two arc tubes 1 and 2 are electrically connected in parallel by power transmission lines 4a, 4b and 5a, 5b which also function as supporting fittings for the arc tubes, and are housed in an outer tube 6 having a diffusion film on its inner surface. ing. Proximity conductors 1a and 2a made of thin metal wires are wound around the arc tubes 1 and 2, respectively. One end of each of the adjacent conductors 1a and 2a has a changeover switch 3
, And the other end is electrically open. The inside of the outer tube 6 is vacuum.

FIG. 2 is a top view showing the structure of the changeover switch 3 portion of the above embodiment. In the figure, one end of the adjacent conductors 1a and 2a and the leaf springs 7a and 7b are welded and fixed to the leaf spring support fittings 8a and 8b fixed to the ceramic substrate 14. Coils 9a and 9b are provided in a part of the power transmission lines 5a and 5b, and a magnetic body 10 provided with a conductive contact 11 is inserted into the coils 9a and 9b.
The magnetic body 10 is supported by a conductive spring 12, and the conductive spring 12 is fixed to a conductive support fitting 13.

Next, the operating principle of the changeover switch 3 will be described with reference to FIG. 3A and 3B show the connection state of the changeover switch 3 when the lamp is off and when it is on. When the lamp is off, the proximity conductor 2a is the conductive support fitting 1
3 is electrically connected. At this time, the power transmission lines 5, 5 '
When a voltage is applied between them, an electric field is applied between the adjacent conductors 2a and 5 ', and the arc tube 2 starts discharging. When the discharge of the arc tube 2 is started, a current flows through the power transmission line 5b, so that a magnetic field is generated in the coil 9b and the magnetic body 10 is attracted to the coil 9b side.
As a result, the contact 11 jumps over the leaf spring 7a and moves to the right. If the arc tube 2 is turned off in this state, the attractive force of the coil 9b is lost, and the repulsive force of the spring 12 causes the leaf spring 7a and the contact 11 to come into contact with each other and stand still. Continue 5,
If a voltage is applied between 5 ', a similar operation occurs on the side of the arc tube 1, so that the arc tubes 1 and 2 are alternately turned on. Although the above is an example of the case where the electromagnetic coils 9a and 9b are installed on the power transmission line 5 side, it is obvious that the same effect can be obtained by installing the electromagnetic coils 9a and 9b on the power transmission line 5'side.

FIG. 4 shows an electrical connection diagram in which the discharge lamp of FIG. 1 is connected to a lamp lighting circuit. In the figure, the broken line 46 is the appearance of the discharge lamp, and the inside of the broken line 46 is the same as the discharge lamp of FIG. Reference numeral 40 is a pulse generator connected to the outside of the discharge lamp. Reference numeral 41 is a ballast, and 42 is a power supply.
The pulse generator 40 may be built in the ballast 41. As illustrated, the changeover switch 3 is assumed to be connected to the adjacent conductor 1a wound around the arc tube 1. When the power supply voltage is applied, the pulse generated by the pulse generator 40 is superimposed on the output voltage of the ballast 41 and simultaneously applied to the arc tubes 1 and 2. However, since the changeover switch 3 is connected to the proximity conductor 1a, only the arc tube 1 is turned on. Arc tube 1
As described above, when a current flows through the switch 3, the changeover switch 3 maintains its state even after the connection is switched to the adjacent conductor 2a and the light is turned off. Similarly, the arc tube 2 is turned on when the power is next applied.

<Second Embodiment> FIG. 5 is an electrical connection diagram of a lamp lighting circuit in another embodiment of the discharge lamp according to the present invention. In this embodiment, two 360 W high pressure sodium lamp arc tubes 1 and 2 electrically connected in parallel are housed inside the outer tube 46, and the proximity conductors 1a and 2a of each arc tube 1 and 2 are changeover switches. Connected to 3. Furthermore, a starter circuit including a resistor 54, a bimetal switch 55 that closes at room temperature and opens at high temperature, and a filament 58 is also incorporated. This lamp is connected to a power source 57 via a ballast 53 for a 400 W mercury lamp.

When a power supply voltage is applied, a current flows through the resistor 54, the bimetal switch 55 and the filament 56 of the starter circuit. When the filament 56 heats the bimetal switch 55 and the switch 55 opens, a pulse is generated by the energy stored in the inductance of the ballast 53. A pulse voltage is applied between the electrodes of the arc tube in superposition with the power supply voltage. Now, as shown in FIG. 5, when the changeover switch 3 is connected to the proximity conductor 1a, the arc tube 1 is turned on. When a current flows through the arc tube 1, the connection is switched to the adjacent conductor 2a by the changeover switch 3 as described in the first embodiment. This state is maintained even after the arc tube 1 is turned off,
Next, the arc tube 2 is turned on when electricity is applied.

<Embodiment 3> FIG. 6 is an electrical connection diagram of a lamp lighting circuit according to still another embodiment of the present invention. In the present embodiment, 250 W metal halide lamp arc tubes 61 and 62 electrically connected in parallel inside the outer tube 66.
2 of which are accommodated, and the auxiliary electrodes 6 of the arc tubes 61 and 62, respectively.
1a and 62a are connected to the changeover switch 3. The changeover switch 3 is connected via a starting resistor 69 to an electrode facing the adjacent main electrode. Further, a starter circuit including a resistor 64, a bimetal switch 65 that closes at room temperature and opens at high temperature, and a glow starter 60 is also incorporated. This lamp has a power supply 6 via a ballast 63 for a 250 W mercury lamp.
Connected to 7.

When the power supply voltage is applied, the glow starter 60 of the starter circuit operates and a pulse is generated by the energy stored in the inductance of the ballast 63. A pulse voltage is applied between the electrodes of the arc tubes 61 and 62 so as to be superimposed on the power supply voltage. Now, when it is connected to the auxiliary electrode 61a as shown in FIG. 6, the arc tube 61 lights up. Arc tube 61
When a current flows through the switch, the changeover switch 3 operates as described in the first embodiment, and the connection is switched to the adjacent conductor 62a.
This state is maintained even after the light emitting tube 61 is turned off, and the light emitting tube 62 is turned on when the power is next applied.

<Embodiment 4> FIG. 7 is a top view of a changeover switch in another embodiment of the discharge lamp according to the present invention. The parts other than the changeover switch are the same as those shown in FIG. The leaf spring 74 is welded and fixed to the leaf spring support fittings 75 and 76 fixed to the ceramic substrate 73. Similarly, a leaf spring support fitting 71 fixed to the ceramic substrate 73
One ends of the bimetal plates 71b and 72b are welded and fixed to the d and 72d. Contacts 71c, 72c are attached to the other ends of the bimetals 71b, 72b. Support bracket 7
Proximity conductors 1a and 2a are connected to 1d and 72d, respectively. The support fitting 79 is connected to one of the lead wires, that is, one electrode of the arc tube. 71e,
Reference numeral 72e is a ceramic shield plate that shields heat radiation from the arc tube and is fixed to the ceramic substrate 73.

In FIG. 7, the leaf spring support metal fitting 76 and the leaf spring 7 are shown.
4, the contact 71c, the support fitting 71d, and the proximity conductor 1a are electrically connected. When the voltage from the power supply circuit is printed in this state, the arc tube 1 around which the proximity conductor 1a is wound is turned on. When the temperature of the arc tube rises, the bimetal 71b receives the radiant heat from the arc tube and is deformed,
It is connected to the contact 72c leaving the contact 71c. The bimetal 72b does not receive the radiant heat from the arc tube 1 by the shield plate 72e, and thus does not pass the leaf spring 74. Therefore, when the arc tube 1 is turned off, the leaf spring connected to one of the electrodes is connected to the adjacent conductor 2a. When the power is next applied, the arc tube 2 around which the adjacent conductor 2a is wound is turned on. In this way, one of the two arc tubes is alternately turned on each time the power is supplied.

The embodiment of the present invention has been described above.
The present invention is not limited to the above embodiments. For example, the number of arc tubes may be three or more.

[0020]

As described above, since the discharge lamp of the present invention has a built-in function of alternately lighting each time it is energized, it is possible to use a mercury lamp ballast or a dedicated ballast that has been widely used in the past. Since the power supply circuit it has can be used directly, it has the advantage that existing equipment can be used. Also,
The life time of the lamp can be set to a time substantially proportional to the number of arc tubes provided in the outer tube. Therefore, it is possible to reduce a great deal of labor and cost for replacing the lamp that has reached the end of its life. Further, since the changeover switch can be realized by a simple means using the starting electrode of the arc tube, its economical effect is great.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of a discharge lamp according to the present invention.

FIG. 2 is a top view of the changeover switch 3 portion of FIG.

FIG. 3 is an electrical connection diagram for explaining the operation of an embodiment of a discharge lamp according to the present invention.

FIG. 4 is an electrical connection diagram in which an embodiment of a discharge lamp according to the present invention is connected to a lamp lighting circuit.

FIG. 5 is an electrical connection diagram in which another embodiment of the discharge lamp according to the present invention is connected to a lamp lighting circuit.

FIG. 6 is an electrical connection diagram in which still another embodiment of the discharge lamp according to the present invention is connected to a lamp lighting circuit.

FIG. 7 is a top view of a changeover switch unit in another embodiment of the discharge lamp according to the present invention.

[Explanation of symbols]

1: arc tube 1 40: pulse generator 1a: proximity conductor of arc tube 1 41: ballast 2: arc tube 2 47, 57, 67: power supply 2a: proximity conductor of arc tube 1 53, 63: stability for mercury lamp Device 3: Changeover switch 54, 64: Resistor 4a, 4b: Power transmission line 55, 65: Normally closed bimetal switch 5, 5 ': Power transmission line 58: Filament 5a, 5b: Power transmission line 60: Glow starter 6, 36, 46 , 56: Outer tube 61, 62: Metal halide lamp arc tube 7a, 7b: Leaf spring 61a, 62a: Auxiliary electrode 8a, 8b: Leaf spring support metal fitting 69: Starting resistance 9a, 9b: Coil 71b, 72b: Bimetal plate 10: Magnetic substance 71c, 72c: Contact point 11: Contact point 71d, 72d: Support metal fitting 12: Conductive spring 71e, 72e: Shield plate 13: Support metal fitting 74: Leaf spring 14, 73: Ceramic substrates 75 and 76: the leaf spring support bracket

Continuation of front page (51) Int.Cl. ⁵ Identification number Reference number in the office FI Technical indication location H01J 61/54 E 7135-5E (72) Inventor Shinichi Shinada 888 Fujihashi, Ome City, Tokyo Hitachi, Ltd. Living Equipment Co., Ltd. Within the business unit

Claims (6)

[Claims] 1. An alternation characterized in that a plurality of arc tubes connected in parallel and a switching control means for alternately switching the lighting of the arc tubes are provided inside an outer tube. Lighting type discharge lamp. 2. The discharge lamp according to claim 1, wherein the switching control means switches the energization to the starting electrode of the arc tube by the electromagnetic force generated by the current flowing through the main electrode of the arc tube. An alternating lighting type discharge lamp characterized by being composed of. 3. The discharge lamp according to claim 2, wherein the electromagnetic switch comprises a coil formed of a part of a power transmission line to the main electrode, a rod-shaped magnetic body inserted in the coil, and the rod-shaped magnetic body. And a switching contact piece for switching to the starting electrode. 4. The discharge lamp according to claim 1, wherein the switching control means is composed of a switch for switching between energization to a starting electrode of the arc tube by a heat responsive switch that is sensitive to heat generated by the arc tube. Alternate lighting type discharge lamp characterized by 5. The discharge lamp according to claim 1, 2, 3 or 4, wherein the starting electrode comprises a proximity conductor wound around each of the plurality of arc tubes, and the arc tube is a sodium lamp. Characteristic alternating lighting high pressure discharge lamp. 6. The discharge lamp according to claim 1, wherein the arc tube is a mercury lamp or a metal halide lamp, and the starting electrode is an auxiliary electrode provided in the vicinity of the main electrode. An alternating lighting type discharge lamp characterized by the following.