JPH08203683A - Electrodeless discharge lamp lighting device - Google Patents

Abstract

PURPOSE: To supply a proper power to an electrodeless discharge lamp at dark place lighting by performing a control so that a power sufficient for dark place starting is supplied to the electrodeless discharge lamp after the power is supplied to the electrodeless discharge lamp. CONSTITUTION: At the dark place lighting of an electrodeless discharge lamp 1, the reflected power of a matching circuit 4 is large, a detecting circuit 8A outputs a H-level voltage V8, the output voltage of a chopper circuit 5 is increased by a control circuit 9, and the voltage V between both ends of an induction coil 2 is increased to start the discharge lamp. After the starting, the detecting circuit 8A outputs the L-level voltage V8, the output voltage of the chopper circuit 5 is reduced, and the voltage between both ends of the coil 2 is reduced to keep the lighting of the discharge lamp 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrodeless discharge lamp which emits light by applying a high frequency electromagnetic field to an electrodeless discharge lamp having a glass bulb filled with a discharge gas such as an inert gas or a metal vapor. The present invention relates to an electric lamp lighting device.

[0002]

2. Description of the Related Art As a conventional example according to the present invention, Japanese Patent Laid-Open No. 6-1
There is one shown in No. 63171.

A conventional electrodeless discharge lamp lighting device of this type which emits light by applying a high-frequency electromagnetic field to the electrodeless discharge lamp (first
Conventional example), as shown in FIG. 5, a discharge gas such as an inert gas or a metal vapor (for example, mercury and a rare gas) in a transparent spherical glass bulb or a spherical glass bulb whose inner surface is coated with a phosphor. Of the electrodeless discharge lamp 1 and a coil 2 for high-frequency power supply (hereinafter, referred to as an induction coil 2) arranged in proximity to each other along the spherical outer circumference of the electrodeless discharge lamp 1.
The impedance of both the induction coil 2 and the high frequency power source 3 is matched with the high frequency power source 3 which is connected to the induction coil 2 and supplies the high frequency power to the induction coil 2. A matching circuit 4 that transmits high-frequency power well, and a chopper circuit 5 that converts the commercial power supply 20 into a DC power supply for applying a DC voltage to the high-frequency power supply 3 are configured.

Then, a high-frequency current of several MHz to several hundred MHz is passed from the high-frequency power supply 3 to the induction coil 2 to generate a high-frequency electromagnetic field in the induction coil 2 and supply high-frequency power to the electrodeless discharge lamp 1. A high-frequency plasma current is generated in the electrodeless discharge lamp 1 to generate ultraviolet rays or visible light.

In general, the discharge electrodeless discharge lamp is left in a dark place for a long time in an unoperated state and then, if it is attempted to be lit in that state (trying to illuminate in a dark place), a normal situation that is not a dark place is given. It is known that it is difficult to start the engine. This is because the gas in the tube always contains some residual ions due to photoelectric effect, cosmic rays, radioactive substances, etc., but by leaving the discharge electrodeless discharge lamp in a dark place without operation, This is because the residual ions are extremely small. In the electrodeless discharge lamp lighting device of FIG. 5, the equivalent circuit of the electrodeless discharge lamp 1 can be represented by a parallel circuit of an equivalent inductance element L0 and an equivalent resistance r0 as shown in FIG. Equivalent resistance r0 at no load
Is infinite, and the equivalent resistance r0 has a finite value during lighting of the electrodeless discharge lamp. Therefore, the voltage across the induction coil 2 when the electrodeless discharge lamp 1 is turned on is as shown in FIG.

In FIG. 7, the power is turned on at time t0, the no-load state continues for the subsequent required lighting time T, and the electrodeless discharge lamp 1 is turned on at time t1 after the required lighting time T elapses and is normally turned on. It shows that it is in a state. In FIG. 7, the voltage V02 indicates the secondary voltage in the unloaded state.

The relationship between the amplitude of the secondary voltage V02 required for lighting the electrodeless discharge lamp 1 and the required lighting time T is estimated as shown in FIG. That is, it is estimated that the amplitude of the secondary voltage V02 and the required lighting time T are in inverse proportion. Under difficult circumstances such as lighting in the dark place described above, the secondary voltage V02 required to light the electrodeless discharge lamp 1 within a certain lighting required time T is higher than that in the normal lighting that is not lighting in the dark place. Become higher.

Discharge with an filament In an electrodeless discharge lamp, the filament is preheated and thermoelectrons are generated, so that it is easy to discharge, but in the electrodeless discharge lamp, there is no filament and the above-mentioned difficult starting condition is remarkable. Will appear in.

Actually, if the electrodeless discharge lamp is left in a dark place for a long time without being operated and an attempt is made to light it in that state, in a normal bright place, a light is instantaneously lighted, or a few seconds later, or The first problem arises in that when the electrodeless discharge lamp is placed in a bright place, the phenomenon of instantaneous lighting as usual occurs.

As means for solving the above-mentioned first problem,
Some of them are shown in FIGS. 9 to 11, which will be described below.
(Second Conventional Example) As shown in FIG. 9, the present electrodeless discharge lamp lighting device includes an induction coil 2 along an electrodeless discharge lamp 1 in which a discharge gas such as an inert gas or a metal vapor is sealed in a glass bulb. Placed in close proximity,
High frequency power supply 3 for supplying high frequency power to the induction coil 2.
Is provided and a matching circuit 4A for impedance matching is provided between the high frequency power supply 3 and the induction coil 2, and the matching circuit 4A is controlled so as to supply more than usual power to the electrodeless discharge lamp 1 when it is difficult to light in a dark place. Control circuit 6
Is provided.

According to the configuration of FIG. 9, the control circuit 6 controls the matching circuit 4A so as to supply electric power larger than usual to the electrodeless discharge lamp 1 when it is difficult to illuminate in the dark. Even when 1 is left in the dark for a long time and the amount of residual ions in the tube is small, it is possible to supply the electrodeless discharge lamp 1 with sufficient power to quickly turn on the electrodeless discharge lamp 1. Therefore, the electrodeless discharge lamp 1 can be easily and quickly turned on in the dark. The details will be described below.

In this electrodeless discharge lamp lighting device, as shown in FIG.
1 is different from the first conventional example shown in FIG. 1 in that instead of the matching circuit 4, a matching circuit 4A whose circuit constant can be switched by at least one switching element is used, and the light receiving for detecting the light emission of the electrodeless discharge lamp 1 is used. The light receiving element 7 is provided with the element 7.
The control circuit 6 is provided to change the power supplied to the induction coil 2, that is, the power supplied to the electrodeless discharge lamp 1 by controlling the on / off of the switching element of the matching circuit 4A according to the output signal of 1. .

The matching circuit 4A comprises, in FIG. 9, four capacitance elements C1 to C4 and two switching elements S1 and S2. The configuration other than the above is the same as that of the electrodeless discharge lamp lighting device of FIG.

The operation will be briefly described below. In a normal state (light place), the switching element S1 is off and the switching element S2 is on. First, the no-load secondary voltage V02 is generated across the induction coil 2 and the electrodeless discharge lamp is lit. At the same time, the voltage drops and stabilizes (voltage V
0).

However, after being left in a dark place for a long time,
Even if the power is turned on in that state, the electrodeless discharge lamp 1 does not light up instantly. Even if a certain time t0 has elapsed after the power was turned on,
When the signal from the light receiving element 7 does not enter the control circuit 6, the control circuit 6 turns on the switching element S1 and turns off the switching element S2. As a result, the current flowing through the matching circuit 4 increases and the voltage across the induction coil 2 also increases. Therefore, the high frequency power applied to the electrodeless discharge lamp 1 is increased more than usual, and sufficient power is applied to light the electrodeless discharge lamp 1 with a small amount of residual ions after being left in the dark, and the electrodeless discharge lamp 1 is lit. Lead to.

However, in this state, the input of the lighting circuit,
Since both outputs are higher than usual, it is necessary to return to normal power. Therefore, when the light receiving element 7 confirms that the electrodeless discharge lamp is turned on, the control circuit 6 returns the switching element S1 to the OFF state and the switching element S2 to the ON state. Then, after that, lighting can be maintained with normal power.

In these operations, the relationship between the elapsed time t after the power is turned on and the voltage V across the induction coil 2 is shown in the graph of FIG. In FIG. 2, the broken line indicates the lighting in the bright place, and the solid line indicates the lighting in the dark place. Further, t0 is a waiting time until the state of lighting in a dark place after the power is turned on, that is, the state in which the power supply to the electrodeless discharge lamp 1 increases. In this way, when it is difficult to light the lamp in the dark, by adding the control circuit 6 that raises the voltage across the induction coil 2, it becomes possible to reliably light the electrodeless discharge lamp 1 even in the dark.

The structure of the matching circuit 4 is not limited to the one shown in FIG. 9, but may be the following one. As shown in FIG. 11, the voltage across the induction coil 2 is controlled according to each structure. May be.

(1) Stepwise control using a plurality of matching elements and switching elements. That is, a plurality of sets of series circuits of the capacitance element C2 and the switching element S1 in FIG. 1 are provided in parallel to turn on or off each of the switching elements S1 in order with the passage of time, and the series circuit of the capacitance element C4 and the switching element S2 is connected. A plurality of sets are provided in parallel, and each switching element S2 is turned on or off in order as time passes. FIG. 11A shows a graph of the relationship between the elapsed time t after the power is turned on and the voltage V across the induction coil 2 at this time.

(2) Capacitance element C in FIG.
2 and the capacitance element C4 are variable capacitors,
The capacity is controlled so as to continuously increase or decrease over time. FIG. 11B is a graph showing the relationship between the elapsed time t after the power is turned on and the voltage V across the induction coil 2 at this time.

It should be noted that the waiting time t0 is not always necessary, but by providing the waiting time t0, it is not necessary to raise the secondary voltage V02 more than necessary at the time of lighting in a bright place, and it is not necessary to increase the power consumption of the lighting circuit. There are advantages.

Instead of controlling the matching circuit 4, it is also possible to control the voltage across the induction coil 2 by changing the switching duty of the chopper circuit 5 and controlling the DC power supply voltage.

[0023]

However, in the above-mentioned first and second conventional examples, it is necessary to supply a large amount of power to the electrodeless discharge lamp 1 at the time of lighting in a dark place, but if the supplied power is too large. A second problem arises in that the high frequency power source 3 is heavily stressed.

Further, the secondary voltage V02 required for lighting the electrodeless discharge lamp 1 has a peculiar variation among a plurality of electrodeless discharge lamps, and the variation is particularly large when lighting in a dark place. Therefore, it is difficult to supply appropriate power to each electrodeless discharge lamp, and in order to solve it, it is necessary to supply large power to all electrodeless discharge lamps. If it is too large, a third problem arises in that the high frequency power source 3 is heavily stressed.

Further, as shown in FIGS. 11A and 11B, when the voltage V across the induction coil 2 is gradually increased,
A fourth problem arises that it takes time before the electrodeless discharge lamp 1 lights up.

The present invention has been made in view of all the above problems, and an object thereof is to provide an electrodeless discharge lamp capable of supplying appropriate electric power to the electrodeless discharge lamp at the time of lighting in a dark place. It is to provide a lighting device.

[0027]

In order to solve the above problems, according to the invention of claim 1, there is provided an electrodeless discharge lamp in which a discharge gas such as an inert gas or a metal vapor is sealed in a glass bulb. , Matching for high-frequency power supply coil closely arranged along the electrodeless discharge lamp, high-frequency power supply for supplying high-frequency power to the high-frequency power supply coil, and impedance matching for both the high-frequency power supply coil and the high-frequency power supply In an electrodeless discharge lamp lighting device equipped with a circuit, after supplying sufficient power for starting the electrodeless discharge lamp to the electrodeless discharge lamp, supplying sufficient power for starting the electrodeless discharge lamp in the dark It is characterized in that a control means for controlling a high frequency power source is provided so as to supply the discharge lamp.

According to the second aspect of the present invention, the control means detects the reflected power of the matching circuit, and when the detected reflected power is a certain value or more, it is sufficient for starting the electrodeless discharge lamp in the dark. A high-frequency power source is controlled so that a large amount of electric power is supplied to the electrodeless discharge lamp.

According to the third aspect of the present invention, the control means detects the reflected power of the matching circuit and, in accordance with the change of the detected reflected power, sufficient power for starting the electrodeless discharge lamp in the dark. Is to control the high-frequency power source so as to supply to the electrodeless discharge lamp.

According to a fourth aspect of the invention, the control means detects the reflected power of the matching circuit and discontinues the power supplied from the high frequency power supply.

[0031]

According to the first aspect of the present invention, the high frequency power source supplies sufficient power for starting the electrodeless discharge lamp to the electrodeless discharge lamp, and then supplies sufficient power for starting the electrodeless discharge lamp in the dark. Supply to electrodeless discharge lamp. After the electrodeless discharge lamp is lit, electric power reduced to a value sufficient to keep the electrodeless discharge lamp lit is supplied to the electrodeless discharge lamp.

According to the second aspect of the present invention, the reflected power of the matching circuit is detected, and if the detected reflected power is equal to or greater than a certain value, sufficient power is supplied from the high frequency power supply for starting the electrodeless discharge lamp in the dark. Supply to electrodeless discharge lamp. After the electrodeless discharge lamp is lit, electric power reduced to a value sufficient to keep the electrodeless discharge lamp lit is supplied to the electrodeless discharge lamp.

According to the third aspect of the present invention, the reflected power of the matching circuit is detected, and in accordance with the change in the detected reflected power value, sufficient power is not supplied from the high frequency power supply for starting the electrodeless discharge lamp in the dark. Supply to the electrode discharge lamp. After the electrodeless discharge lamp is lit, electric power reduced to a value sufficient to keep the electrodeless discharge lamp lit is supplied to the electrodeless discharge lamp.

According to the fourth aspect of the present invention, the reflected power of the matching circuit is detected and the power supplied from the high frequency power supply is discontinuous to reduce the stress applied to the high frequency power supply.

[0035]

【Example】

(Embodiment 1) A circuit diagram of a first embodiment according to the present invention is shown in FIG.

The difference from the first conventional example shown in FIG. 5 is that the matching circuit 4 is clamped, that is, the matching circuit 4 is clamped.
Is provided with a detection circuit 8A for detecting the reflected power of the above, and a chopper control circuit 9 for controlling the output voltage of the chopper circuit 5 by receiving the detection output of the detection circuit 8A. The same reference numerals will be given to those, and description thereof will be omitted.

Here, the detection circuit 8A detects the voltage V across the induction coil 2 as a diode D11 and a capacitance element C1.
The voltage VC11 which is rectified and smoothed by 1 and divided by the resistors R11, R12 and the Zener diode ZD1 and the reference voltage V10
Are compared and output by the comparator IC10, and when the voltage VC11 exceeds the reference voltage V10, a high (H) level, voltage VC1
When 1 is lower than the reference voltage V10, a rectangular wave voltage V8 that becomes a low (L) level is output.

Further, the chopper control circuit 9 controls the H of the voltage V8.
The output voltage of the chopper circuit 5 is controlled according to the level and the L level.

Next, the operation will be briefly described. When the electrodeless discharge lamp 1 is lit in a dark place, that is, when the reflected power of the matching circuit 4 is large, the detection circuit 8A causes the H level voltage V8.
Is output, the output voltage of the chopper circuit 5 is increased by the chopper control circuit 9 to increase the voltage V across the induction coil 2 and the electrodeless discharge lamp 1 is started.

After the electrodeless discharge lamp 1 is started, that is, when the reflected power of the matching circuit 4 is small, the detection circuit 8A is L level.
Since the level voltage V8 is output, the chopper control circuit 9
Thus, the output voltage of the chopper circuit 5 is reduced, the voltage V across the induction coil 2 is reduced, and the electrodeless discharge lamp 1 is kept lit.

(Second Embodiment) A circuit diagram of a second embodiment according to the present invention is shown in FIG.

The difference from the first embodiment shown in FIG. 1 is that a detection circuit 8B for detecting the current flowing through the matching circuit 4 is provided instead of the detection circuit 8A.
The same components as those in the embodiment are designated by the same reference numerals and the description thereof will be omitted.

Here, the detection circuit 8B is the matching circuit 4
The secondary current flowing in the secondary winding of the current transformer T10 in which the primary winding is connected in series to the capacitive element C0 that constitutes the capacitor C12 charges the capacitive element C12 via the diode D11 and the resistor R13.
The voltage VC12 across 12 and the reference voltage V10 are compared and output by the comparator IC10, and the voltage VC12 becomes the reference voltage V1.
When it exceeds 0, the H level and the voltage VC12 become the reference voltage V10.
When it is lower than, the rectangular wave voltage V8 which becomes L level is output.

In the first and second embodiments described above, if the chopper circuit 5 obtains a continuous DC voltage, in the unloaded state, as shown by the solid line in FIG. 3 (a), Since the voltage V across the induction coil 2 is always the voltage V1, the high frequency power supply 3 is stressed. Therefore, in order to reduce the stress applied to the high frequency power source 3 in the unloaded state, the voltage V across the induction coil 2 may be discontinuous as shown in FIG. 3B, that is, in the unloaded state. In that case, the chopper circuit 5 may be configured to be able to obtain a discontinuous DC voltage.

In the loaded state, as shown by the broken line in FIG. 3 (a), the time t0 at which the electrodeless discharge lamp 1 starts and lights up.
Then, the voltage V across the induction coil 2 decreases from V1 to V0.

With the configuration as shown in the first and second embodiments, the voltage across the induction coil 2 can be increased only when the electrodeless discharge lamp 1 is started.

(Third Embodiment) FIG. 4 shows a circuit diagram of a third embodiment according to the present invention.

The difference from the first embodiment shown in FIG. 1 is that an impedance converter IC20 is provided in place of the comparator IC10 so that the voltage VC11 and the voltage V8 are substantially equal, and the other first embodiment. The same components as those in FIG.

With this configuration, the output voltage of the chopper circuit 5 is determined according to the change in the voltage V across the induction coil 2, that is, the reflected power of the matching circuit 4, so that the electrodeless discharge lamp 1 is started. At some time, appropriate power can be supplied by the electrodeless discharge lamp 1.

In all the above-mentioned embodiments, the high frequency power source 3 may be any one capable of supplying high frequency power such as a half bridge inverter circuit. Further, instead of controlling the chopper circuit 5, for example, the matching circuit 4 may be controlled or the high frequency power source 3 may be controlled to control the electric power supplied to the electrodeless discharge lamp 1.

[0051]

According to the inventions of claims 1 to 3, it is possible to provide an electrodeless discharge lamp lighting device capable of supplying appropriate power to the electrodeless discharge lamp at the time of starting in the dark.

According to the invention described in claim 4, the electrodeless discharge lamp lighting device capable of reducing the stress applied to the high frequency power source and capable of supplying appropriate power to the electrodeless discharge lamp at the time of starting in the dark. Can be provided.

[Brief description of drawings]

FIG. 1 shows a circuit diagram of a first embodiment according to the present invention.

FIG. 2 shows a circuit diagram of a second embodiment according to the present invention.

3A and 3B are waveform diagrams showing changes in the voltage across a coil for supplying high-frequency power of an electrodeless discharge lamp according to the first and second conventional examples, and FIG. 3B is related to the first and second examples. It is a waveform diagram.

FIG. 4 shows a circuit diagram of a third embodiment according to the present invention.

FIG. 5 shows a circuit diagram of a first conventional example according to the present invention.

FIG. 6 shows an equivalent circuit diagram of an electrodeless discharge lamp.

FIG. 7 is a waveform diagram showing changes in the voltage across the coil for supplying high-frequency power when the electrodeless discharge lamp is lit.

FIG. 8: Time required for lighting an electrodeless discharge lamp and 2 required for lighting
It is a characteristic view which shows the relationship with the next voltage.

FIG. 9 shows a circuit diagram of a second conventional example according to the present invention.

FIG. 10 is a waveform diagram showing changes in both-end voltage of the high-frequency power supply coil during lighting in a dark place and lighting in a bright place of the electrodeless discharge lamp according to the conventional example.

FIG. 11 is a waveform diagram showing another example of changes in the voltage across the high-frequency power supply coil when the electrodeless discharge lamp is lit in the dark according to the conventional example.

[Explanation of symbols]

 1 electrodeless discharge lamp 2 high frequency power supply coil 3 high frequency power supply 4 matching circuit

Claims (4)

[Claims] 1. An electrodeless discharge lamp in which a discharge gas such as an inert gas or a metal vapor is sealed in a glass bulb, a high-frequency power supply coil arranged in proximity to the electrodeless discharge lamp, and the high-frequency power. In the electrodeless discharge lamp lighting device, comprising: a high frequency power supply for supplying high frequency power to a supply coil; and a matching circuit for impedance matching of both the high frequency power supply coil and the high frequency power supply, A control for controlling the high-frequency power source so as to supply the electrodeless discharge lamp with sufficient power for starting the dark place of the electrodeless discharge lamp after supplying sufficient power for starting the electric lamp to the electrodeless discharge lamp. An electrodeless discharge lamp lighting device comprising means. 2. The control means detects the reflected power of the matching circuit, and when the detected reflected power is a certain value or more, the control means supplies sufficient power for starting the electrodeless discharge lamp in a dark place. The electrodeless discharge lamp lighting device according to claim 1, wherein the high-frequency power supply is controlled so as to be supplied to the electrodeless discharge lamp. 3. The control means detects the reflected power of the matching circuit, and supplies sufficient power for starting the electrodeless discharge lamp in a dark place in accordance with a change in the detected reflected power. The electrodeless discharge lamp lighting device according to claim 1, wherein the high-frequency power supply is controlled so as to be supplied to a discharge lamp. 4. The control means detects the reflected power of the matching circuit and discontinues the power supplied from the high frequency power supply.
The electrodeless discharge lamp lighting device according to claim 3.