JP2006040726A - Electrodeless discharge lamp lighting device and illumination device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrodeless discharge lamp lighting device capable of evading circuit breakage when disorder of heat radiation is generated, and an illumination device. <P>SOLUTION: When a ferrite core 11 of a coupler 1b reaches high temperature, since the maximum flux density of the ferrite core 11 is lowered and a flux saturation is generated, an induction coil current Il becomes pulse-shaped current at the peak of sinusoidal wave, and a differentiating circuit 2e, to which a current detection signal is input from a current detection part 2d, detects a signal V1 at every peak of the induction coil current I1. When an output signal V1 of the differentiating circuit 2e exceeds a prescribed value, the output level of a comparator Comp1 is converted into an H-level from an L-level, an oscillation control part K2, to which the H-level signal is input, turns a switch element SW1 on, the oscillation operation of switching elements Q1, Q2 is stopped by short-circuiting a gate terminal of the switching element Q2 with ground level, and the light is put out by turning the induction coil current I1 into zero. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrodeless discharge lamp lighting device and a lighting fixture.

  Conventionally, there is an electrodeless discharge lamp lighting device for lighting an electrodeless discharge lamp.

  The electrodeless discharge lamp has a substantially spherical glass bulb in which mercury vapor or discharge gas is sealed, and has a cylindrical recess. A phosphor is coated on the inner surface of the glass bulb.

  The electrodeless discharge lamp lighting device consists of a ferrite core inserted in a cylindrical hollow of a glass bulb, an induction coil wound around the outer periphery of the ferrite core, and a heat conductor that radiates heat from the ferrite core and induction coil to the outside. And a high frequency power source for supplying a high frequency current to the induction coil.

  When a high frequency current is supplied from the high frequency power source to the induction coil, a high frequency electromagnetic field is generated around the induction coil. Then, mercury vapor in the electrodeless discharge lamp is excited to generate ultraviolet rays. When ultraviolet light hits the phosphor on the inner surface of the glass bulb, it is converted into visible light, and the electrodeless discharge lamp is turned on.

When the electrodeless discharge lamp is lit, the heat generated by the discharge heats the induction coil and the ferrite core of the coupler, or the coupler becomes high temperature due to heat generated by iron loss and copper loss. Therefore, in order to prevent the problem that the induction coil exceeds its heat resistance temperature and the ferrite core exceeds the Curie temperature, the bottom of the coupler is placed in contact with the main body of the lighting fixture to dissipate heat. (For example, see Patent Document 1)
In addition, as an operation for protecting the overvoltage and overcurrent of the electrodeless discharge lamp lighting device, there is one that stops the lighting operation when an overvoltage or overcurrent is detected. (For example, see Patent Document 2)
Japanese National Patent Publication No. 11-501152 (page 7, lines 21-24, FIG. 1) JP 2000-68085 A (paragraph numbers [0035] to [0043], FIG. 1)

  As shown in the above conventional example, when the coupler is installed in contact with the main body of the lighting fixture and the structure is such that the heat of the induction coil or ferrite core is released to the fixture by the coupler's thermal conductor, If the heat of the coupler cannot be sufficiently dissipated due to insufficient mounting conditions or due to factors such as aging, the heat resistance of the coupler cannot be sufficiently dissipated. Or the ferrite core may exceed the Curie temperature and the circuit may be damaged.

  This invention is made | formed in view of the said reason, The objective is to provide the electrodeless discharge lamp lighting device and lighting fixture which can avoid circuit destruction, when the malfunction of heat dissipation arises.

  The invention according to claim 1 is a heat conduction for dissipating the heat of the core, the induction coil, the core and the induction coil disposed in the depression of the electrodeless discharge lamp having an approximately spherical appearance and having at least one depression. A coupler having a body, a high-frequency power source for supplying high-frequency current to the induction coil, a magnetic flux saturation detecting unit for detecting magnetic flux saturation of the core, and when the magnetic flux saturation detecting unit detects the magnetic flux saturation of the core, And a current control unit for reducing the output current.

  According to the present invention, in the electrodeless discharge lamp lighting device having a structure in which the coupler is installed in the main body of the lighting fixture and the heat of the induction coil and the ferrite core is released to the fixture by the heat conductor of the coupler, a problem of heat dissipation occurs. When the temperature of the coupler rises abnormally, the magnetic flux saturation of the core due to the abnormal rise in temperature is detected and the output current of the high-frequency power supply is reduced, so that it is possible to avoid circuit breakdown when a heat dissipation failure occurs.

  According to a second aspect of the present invention, in the first aspect, the magnetic flux saturation detection unit includes a current detection unit that detects an output current of the high-frequency power source and outputs a current detection signal, and a differential that calculates a differential value of the current detection signal. And the current control unit reduces the output current of the high-frequency power supply when the differential value of the current detection signal exceeds a predetermined value.

  According to the present invention, the magnetic flux saturation of the core can be detected by differentiating the output current of the high frequency power source and detecting a steep change in the output current.

  According to a third aspect of the present invention, in the first aspect, the magnetic flux saturation detection unit detects a magnetic flux density due to an output current of the high-frequency power source and outputs a magnetic flux density detection signal, and a magnetic flux density detection signal A differential circuit for calculating a differential value, wherein the current control unit reduces the output current of the high-frequency power source when the differential value of the magnetic flux density detection signal is substantially zero for a predetermined period.

  According to the present invention, the magnetic flux saturation of the core can be detected by differentiating the magnetic flux density due to the output current of the high-frequency power source and detecting the constant state of the magnetic flux density.

  A fourth aspect of the present invention is characterized in that, in the third aspect, the magnetic flux density detection unit is constituted by a detection coil wound around an outer periphery of the electrodeless discharge lamp.

  According to the present invention, the magnetic flux saturation of the core can be detected and a noise reduction effect can be realized at the same time.

  A fifth aspect of the present invention provides the current control unit according to any one of the first to fourth aspects, wherein the electrodeless discharge lamp and a coupler constitute a lamp unit and includes an output current adjusting element that reduces an output current of the high-frequency power source. And the magnetic flux saturation detector and the differential circuit are provided in a lamp unit.

  According to the present invention, the lamp unit can be wired only by a high-frequency current supply line from a high-frequency power source, and the configuration can be simplified.

  The invention of claim 6 uses the electrodeless discharge lamp lighting device according to any one of claims 1 to 5.

  According to this invention, the lighting fixture which can have the same effect as any one of Claims 1 thru | or 5 can be provided.

  As described above, in the present invention, when a heat radiation failure occurs and the temperature of the coupler abnormally rises, the magnetic flux saturation of the core is detected and the output current of the high frequency power supply is reduced. There is an effect that circuit destruction can be avoided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 2 shows a cross-sectional view of a lighting fixture A using the electrodeless discharge lamp lighting device of the present embodiment, and the lighting fixture is used for a street lamp fixture. The luminaire A includes a lamp unit 1 and a circuit unit 2 housed in an outer shell 3, and the outer shell 3 has a bowl-shaped outer peripheral portion 3a having both ends opened, and one end opening of the outer peripheral portion 3a. It comprises a metal top plate 3b to be covered and a metal instrument base 3c to be covered at the other end opening of the outer peripheral portion 3a.

  A concave portion 30 is provided at substantially the center of the inner surface of the instrument base 3c. The mounting member 4 has a flange portion 4a attached to the opening periphery of the concave portion 30, and a U-shaped cross section having a peripheral portion attached to the inner side surface of the concave portion 30. Are attached to the instrument base 3c. The lamp unit 1 is mounted on the mounting member 4, the circuit unit 2 is mounted on the mounting member 5, and the lamp unit 1 and the circuit unit 2 are connected by wiring 6.

  The lamp unit 1 is an electrodeless discharge lamp, and includes a glass bulb 1a, a coupler 1b, and a unit base 1c. The glass bulb 1a is formed in a substantially spherical shape, and is filled with mercury vapor or discharge gas. Is coated with a phosphor and has a cylindrical depression 10 on its surface. The coupler 1b includes a cylindrical ferrite core 11 inserted into the hollow 10 of the glass bulb, an induction coil 12 wound around the outer periphery of the ferrite core 11, and one end of the ferrite core 11 in contact with the inner surface of the ferrite core 11 And a rod-shaped heat conductor 13 for radiating the heat of the induction coil 12 to the outside. And the collar part 13a provided in the other end side of the heat conductor 13 is attached on the attachment member 4, and the other end side of the coupler 1b is accommodated in the unit base 1c.

  The circuit unit 2 is a high-frequency power source that supplies a high-frequency current to the induction coil 12. When a high-frequency current is supplied from the circuit unit 2 to the induction coil 12, a high-frequency electromagnetic field is generated around the induction coil 12. Then, the mercury vapor in the glass bulb 1a is excited and generates ultraviolet rays. When the ultraviolet light hits the phosphor on the inner surface of the glass bulb 1a, it is converted into visible light and lit.

  In such an electrodeless discharge lamp lighting device, in order to maintain the temperature of the ferrite core 11 and the induction coil 12 at the time of lighting below a desired value, heat is transferred from the heat conductor 13 to the appliance base 3c via the mounting member 4. It is necessary to communicate efficiently. For this purpose, in the contact portion a between the flange 13a of the heat conductor 13 and the mounting member 4, and in the contact portion b of the flange 4a of the mounting member 4 and the instrument base 3c, the flange 13a, the mounting member 4 and the flange The state in which the part 4a and the instrument base 3c are in sufficient contact and the thermal resistance is low is an essential condition. However, if a gap occurs in the contact portions a and b due to vibration, or rust or the like occurs due to aging and the thermal resistance increases, the heat of the coupler 1b cannot be sufficiently dissipated and the temperature of the coupler 1b rises abnormally, and the ferrite core 11 may exceed the Curie temperature, or the induction coil 12 may exceed its heat resistance temperature, leading to circuit destruction.

  Therefore, this electrodeless discharge lamp lighting device is provided with means for preventing circuit destruction when the temperature of the coupler 1b abnormally rises, and its circuit configuration is shown in FIG.

  The circuit unit 2 includes a power supply unit 2a that converts the input commercial power supply AC into a DC voltage, an inverter unit 2b that converts the DC voltage into high-frequency power, and high-frequency power output from the inverter unit 2b to the lamp unit 1 efficiently. A matching circuit 2c for transmitting, a current detection unit 2d configured by a current transformer that detects an induction coil current I1 that the inverter unit 2b outputs to the induction coil 12 through the matching circuit 2c, and a current detection unit 2d output A differentiation circuit 2e that calculates a differential value of the current detection signal, and a current control unit 2f that reduces the induction coil current I1 when the differential value of the current detection signal exceeds a predetermined value.

  The inverter unit 2b includes switching elements Q1 and Q2 such as FETs connected in series between output terminals of the power supply unit 2a, and a drive unit K1 that drives the switching elements Q1 and Q2 on and off. Both ends are used as high-frequency power output ends.

  The matching circuit 2c includes a series circuit of an inductor L1 and a capacitor C1 connected between both ends of the switching element Q2, a capacitor C2 having one end connected to a connection point between the inductor L1 and the capacitor C1, and a capacitor C1 and the switching element Q2. The other end of each of the capacitors C2 and C3 is connected to each end of the induction coil 12 via the wiring 6. The connection point between the capacitor C1 and the switching element Q2 is connected to the ground potential.

  The current detection unit 2d includes a diode D1 that rectifies the current detection signal.

  The differentiation circuit 2e includes a capacitor C4 having one end connected to the output of the current detection unit 2d, and a resistor R1 connected between the other end of the capacitor C4 and the ground potential.

  The current control unit 2f includes a comparator Comp1 in which the connection point between the capacitor C4 and the resistor R1 is connected to the non-inverting input terminal, a resistor R2 in which one end is connected to the control power supply, and the other end is connected to the inverting input terminal of the comparator Comp1. The resistor R3 having one end connected to the inverting input terminal of the comparator Comp1 and the other end connected to the ground potential, the switch element SW1 for short-circuiting / cutting off the gate terminal of the switching element Q2 to the ground, and the output of the comparator Comp1 The oscillation control unit K2 is configured to turn on / off the switch element SW1.

  Next, the circuit operation when the temperature of the coupler 1b rises abnormally will be described. As described above, when the coupler 1b cannot sufficiently dissipate heat due to a mounting failure between the heat conductor 13 and the mounting member 4 and the temperature of the ferrite core 11 of the coupler 1b becomes high, the maximum magnetic flux density of the ferrite core 11 is increased. Decreases. Then, since the magnetic flux saturation of the ferrite core 11 occurs near the peak of the induction coil current I1, the induction coil current I1 is in the period Ts in which the magnetic flux near the peak of the sine wave is saturated, as shown in FIG. A steep pulsed current flows. If such a state continues, excessive stress is applied to the circuit constituent elements such as the switching elements Q1 and Q2 of the inverter circuit 2b, resulting in circuit destruction.

  However, in this embodiment, the current detector 2d and the differentiation circuit 2e constitute a magnetic flux saturation detector that detects the magnetic flux saturation of the ferrite core 11, and an induction coil current I1 flows as shown in FIG. In this case, a current detection signal having the same waveform as that shown in FIG. 3A is input to the differentiation circuit 2e via the current detection unit 2d. Due to the magnetic flux saturation of the ferrite core 11, the slope near the peak of the induction coil current I1 is steep, and the differentiation circuit 2e can detect the signal V1 for each peak of the induction coil current I1, as shown in FIG. Become. When the output signal V1 of the differentiating circuit 2e exceeds the divided value by the resistors R2 and R3, the output of the comparator Comp1 is inverted from the L level to the H level, and the H level signal is input to the oscillation control unit K2.

  The oscillation control unit K2 to which the H level signal is input turns on the switch element SW1, shorts the gate terminal of the switching element Q2 to the ground level, stops the oscillation operation of the switching elements Q1 and Q2, and induces an induction coil current. By turning off the light by setting I1 to 0, excessive stress is applied to the circuit constituent elements such as the switching elements Q1, Q2, and the circuit is prevented from being destroyed.

  In addition, when the magnetic flux saturation of the ferrite core 11 is detected once by the current detection unit 2d and the differentiation circuit 2e, a coupler lamp (not shown) can be visually confirmed from the outside by a method such as turning on a pilot lamp. The mounting of 1b and the heat dissipation effect can be easily checked.

  Furthermore, the electrodeless discharge lamp is characterized by a long life, and it may be used in dangerous places (for example, lighting in tunnels), so it is not turned off at the time of abnormality as described above. It is also possible to suppress the heat generation of the coupler 1b by lowering the effective value of the induction coil current I1 by blinking when abnormal.

(Embodiment 2)
FIG. 4 shows a circuit configuration of the electrodeless discharge lamp lighting device of the present embodiment. The same reference numerals are given to the same configurations as those of the first embodiment, and the description thereof will be omitted.

  The drive unit K1 of the inverter unit 2b is provided with an output frequency setting terminal, and the output frequency can be set by a circuit constant connected to the frequency setting terminal.

  Therefore, in this embodiment, a parallel circuit of the variable resistor VR1 and the capacitor C5 is connected to the frequency setting terminal of the drive unit K1, and the resistance value of the variable resistor VR1 is switched by the output of the oscillation control unit K2, so that the frequency setting terminal The circuit constant to be connected is switched.

  When the output signal V1 of the differentiating circuit 2e exceeds the divided voltage value by the resistors R2 and R3 due to the magnetic flux saturation of the ferrite core 11, the output of the comparator Comp1 is inverted from the L level to the H level. The oscillation control unit K2 to which the H level signal is input switches the resistance value of the variable resistor VR1 to change the drive frequency of the inverter unit 2b, and reduces the induction coil current I1 to dim the electrodeless discharge lamp. Thus, the heat generation of the coupler 1b is suppressed.

  Therefore, it is possible to reduce visual discomfort at the time of abnormality compared to the first embodiment where the light is turned off at the time of abnormality.

  In addition, the lighting fixture A as shown in FIG. 2 can be comprised similarly to Embodiment 1 using the electrodeless discharge lamp lighting device of this embodiment.

(Embodiment 3)
FIG. 5 shows a circuit configuration of the electrodeless discharge lamp lighting device of the present embodiment, and the same components as those of the second embodiment are denoted by the same reference numerals and the description thereof is omitted.

  The current detection unit 2d of this embodiment does not use a current transformer, and includes a diode D1 having an anode connected to one output terminal of the matching circuit 2c, and a capacitor C6 connected between the cathode of the diode D1 and the ground level. The current detection signal is output from the connection point of the capacitors C6 and C7.

  In addition, the lighting fixture A as shown in FIG. 2 can be comprised similarly to Embodiment 1 using the electrodeless discharge lamp lighting device of this embodiment.

(Embodiment 4)
FIG. 6 shows a circuit configuration of the electrodeless discharge lamp lighting device of the present embodiment. The same reference numerals are given to the same configurations as those of the first embodiment, and the description thereof will be omitted.

  This embodiment includes a magnetic flux density detector 2g that detects a magnetic flux density B1 generated by the induction coil current I1 and outputs a magnetic flux density detection signal instead of the current detector 2d. The magnetic flux density detector 2g The detection coil La is wound around the outer periphery of the ferrite core 11. The magnetic flux density detector 2g and the differential circuit 2e constitute a magnetic flux saturation detector that detects the magnetic flux saturation of the ferrite core 11.

  Next, circuit operation when the temperature of the coupler 1b abnormally rises will be described. As described above, when the heat radiation of the coupler 1b cannot be sufficiently radiated due to a mounting failure between the heat conductor 13 and the mounting member 4, and the ferrite core 11 of the coupler 1b becomes high temperature, the maximum magnetic flux density of the ferrite core 11 is increased. Decreases. Then, the magnetic flux density B1 of the ferrite core 11 due to the induction coil current I1 is saturated in the vicinity of the peak as shown in FIG. 7B, and the induction coil current I1 is a sine wave peak as shown in FIG. 7A. Then, it becomes a steep pulsed current. At this time, a voltage corresponding to the magnetic flux density B1 is generated at both ends of the detection coil La, and the both-end voltage of the detection coil La and the detection coil current I2 shown in FIG. It becomes a constant value during the period Ts when the magnetic flux is saturated.

  When the output of the detection coil La is input to the differentiation circuit 2e as a magnetic flux density detection signal, the output voltage of the differentiation circuit 2e is a period Ts during which the magnetic flux of the ferrite core 11 is saturated, as shown in FIG. Becomes 0.

  Therefore, when the output of the differentiating circuit 2e becomes 0 for a predetermined period or longer, the oscillation control unit K2 outputs an H level signal to turn on the switch element SW1, and short-circuit the gate terminal of the switching element Q2 to the ground level. By stopping the oscillation operation of the switching elements Q1 and Q2 and turning off the induction coil current I1 to 0, excessive stress is applied to the circuit constituent elements such as the switching elements Q1 and Q2, and the circuit is destroyed. It is preventing.

  In the present embodiment, the magnetic flux density detection signal output from the magnetic flux density detection unit 2g is not configured to generate a pulse at the time of abnormality as the current detection signal output from the current detection unit 2d of the first to third embodiments. An element used for the magnetic flux density detection unit 2g may be a small withstand voltage and current withstand capability, and an inexpensive and small element can be used.

  In addition, the current detection unit 2d of the first to third embodiments is provided together with the magnetic flux density detection unit 2g of the present embodiment, and the sudden change of the induction coil current I1 and the voltage across the detection coil La become 0 over a predetermined period. If this happens at the same time, the magnetic flux saturation of the ferrite core 11 can be detected with higher accuracy by turning on the switch element SW1 to perform the protective operation, thereby preventing circuit breakdown.

  In addition, the lighting fixture A as shown in FIG. 2 can be comprised similarly to Embodiment 1 using the electrodeless discharge lamp lighting device of this embodiment.

(Embodiment 5)
FIG. 8 shows a circuit configuration of the electrodeless discharge lamp lighting device of the present embodiment. The same reference numerals are given to the same components as those of the fourth embodiment, and the description thereof will be omitted.

  The electrodeless discharge lamp is lit by the electromagnetic field generated by the induction coil 12, but at the same time, the induction coil 12 becomes a source of radiation noise. Here, it is known that providing a conductor on the outer periphery of the electrodeless discharge lamp has a noise reduction effect.

  Therefore, in the present embodiment, by winding the detection coil La of the magnetic flux density detector 2g around the outer periphery of the glass bulb 1a, the same role as winding the conductor around the outer circumference of the glass bulb 1a is achieved. Similar to the fourth embodiment, the magnetic flux saturation of the ferrite core 11 is detected, and the noise reduction effect is realized at the same time.

  In addition, the lighting fixture A as shown in FIG. 2 can be comprised similarly to Embodiment 1 using the electrodeless discharge lamp lighting device of this embodiment.

(Embodiment 6)
FIG. 9 shows a cross-sectional view of the lamp unit 1 of the present embodiment, and the same components as those of the fourth embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the fourth and fifth embodiments, a wiring for transmitting a magnetic flux density detection signal is required between the lamp unit 1 and the circuit unit 2. Therefore, in the present embodiment, the lamp unit 1 completes from the detection of the magnetic flux density to the control of the induction coil current I1 by the oscillation control unit K2, thereby eliminating the need for the wiring.

  Specifically, the differentiation circuit 2e, the current control unit 2f, and the magnetic flux density detection unit 2g are provided in the unit base 1c of the lamp unit 1, and the power source 2h for operating the current control unit 2f is also provided in the unit base 1c. ing.

  The current control unit 2f includes a switching element Q3 such as an FET connected in series to the induction coil 12 in the unit base 1c, and the oscillation control unit K2 applies a gate voltage to the switching element Q3 when the magnetic flux of the ferrite core 11 is saturated. Thus, the induction coil current I1 is reduced by changing the drain-source resistance of the switching element Q3.

  The power source 2h includes a rectifier circuit DB1 that rectifies the voltage across the detection coil La of the magnetic flux density detector 2g, and a capacitor C6 that smoothes the output of the rectifier circuit DB1, and the voltage across the capacitor C6 is the current controller. 2f.

  As described above, in this embodiment, there is no need for a wiring for transmitting the magnetic flux density detection signal of the magnetic flux density detection unit 2g to the circuit unit 2, and the wiring between the lamp unit 1 and the circuit unit 2 is only the wiring 6 for supplying a high-frequency current. In other words, the same effect as that of the fourth embodiment is realized while simplifying the configuration.

  In the present embodiment, the fourth embodiment has been described as an example. However, in the fifth embodiment as well, from the detection of the magnetic flux density to the control of the induction coil current I1 by the oscillation control unit K2 is completed by the lamp unit 1. If constituted in this way, the same effect can be obtained. Further, in the first to third embodiments, the detection from the induction coil current I1 to the control of the induction coil current I1 by the oscillation control unit K2 may be completed by the lamp unit 1.

  In addition, the lighting fixture A as shown in FIG. 2 can be comprised similarly to Embodiment 1 using the lamp unit of this embodiment.

It is a figure which shows the circuit structure of the electrodeless discharge lamp lighting device of Embodiment 1 of this invention. It is sectional drawing which shows the structure of a lighting fixture same as the above. It is a figure which shows the waveform of each part same as the above, (a) is an induction coil electric current, (b) is a differentiation circuit output signal. It is a figure which shows the circuit structure of the electrodeless discharge lamp lighting device of Embodiment 2 of this invention. It is a figure which shows the circuit structure of the electrodeless discharge lamp lighting device of Embodiment 3 of this invention. It is a figure which shows the circuit structure of the electrodeless discharge lamp lighting device of Embodiment 4 of this invention. It is a figure which shows the waveform of each part same as the above, (a) is an induction coil current, (b) is magnetic flux density, (c) is a detection coil current, (d) is a differentiation circuit output signal. It is a figure which shows the circuit structure of the electrodeless discharge lamp lighting device of Embodiment 5 of this invention. It is sectional drawing which shows the structure of the lamp unit of Embodiment 6 of this invention.

Explanation of symbols

A lighting fixture 1 lamp unit 2 circuit unit 1a glass bulb 1b coupler 10 depression 11 ferrite core 12 induction coil 13 thermal conductor 2b inverter unit 2d current detection unit 2e differentiation circuit 2f current control unit K2 oscillation control unit SW1 switch element

Claims (6)

A coupler provided with a core, an induction coil, a core and a heat conductor for dissipating heat of the induction coil, disposed in a depression of an electrodeless discharge lamp having a substantially spherical appearance and having at least one depression;
A high frequency power supply for supplying high frequency current to the induction coil;
A magnetic flux saturation detector for detecting the magnetic flux saturation of the core;
An electrodeless discharge lamp lighting device comprising: a current control unit that reduces an output current of a high-frequency power supply when the magnetic flux saturation detection unit detects magnetic flux saturation of the core. The magnetic flux saturation detection unit includes a current detection unit that detects an output current of the high-frequency power source and outputs a current detection signal, and a differentiation circuit that calculates a differential value of the current detection signal, and the current control unit 2. The electrodeless discharge lamp lighting device according to claim 1, wherein when the differential value of the detection signal exceeds a predetermined value, the output current of the high-frequency power source is reduced. The magnetic flux saturation detection unit includes a magnetic flux density detection unit that detects a magnetic flux density due to an output current of the high-frequency power source and outputs a magnetic flux density detection signal, and a differentiation circuit that calculates a differential value of the magnetic flux density detection signal, 2. The electrodeless discharge lamp lighting device according to claim 1, wherein the current control unit reduces the output current of the high-frequency power source when the differential value of the magnetic flux density detection signal is substantially zero for a predetermined period. The electrodeless discharge lamp lighting device according to claim 3, wherein the magnetic flux density detection unit includes a detection coil wound around an outer periphery of the electrodeless discharge lamp. A lamp unit is constituted by the electrodeless discharge lamp and the coupler, and the current control unit including an output current adjusting element that reduces the output current of the high-frequency power source, the magnetic flux saturation detection unit, and the differentiation circuit are combined into a lamp unit. The electrodeless discharge lamp lighting device according to claim 1, wherein the electrodeless discharge lamp lighting device is provided. 6. An illuminator using the electrodeless discharge lamp lighting device according to claim 1.

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