JP4186787B2 - Electrodeless discharge lamp lighting device and lighting device - Google Patents

Description

  The present invention relates to an electrodeless discharge lamp lighting device that emits light by applying a high-frequency electromagnetic field to a translucent bulb in which a discharge gas is sealed, and an illumination device using the same.

An example of a conventional electrodeless discharge lamp lighting device is disclosed in, for example, Japanese Patent Laid-Open No. 6-1888091 (Patent Document 1). In this conventional example, an electrodeless discharge lamp is caused to emit light by the action of a high-frequency electromagnetic field generated by an induction coil, which is connected to a power conversion circuit that generates a high-frequency voltage from a DC power supply voltage and an output of the power conversion circuit. And an induction coil. The power conversion circuit includes a switching circuit that switches a DC power supply voltage at a high frequency, and a resonance circuit connected to an output of the switching circuit. The control circuit of the electrodeless discharge lamp lighting device includes detection means for detecting the voltage of the resonance circuit and control means for influencing the control voltage of the switching element according to the detection result of the detection means. That is, when a relatively high voltage is generated in the resonance circuit at the start of firing, the switching element is controlled in a direction to shorten the ON period, the operating frequency of the switching circuit is increased, and the voltage of the resonance circuit is decreased. As a result, when starting the electrodeless discharge lamp lighting device, the amplitude of the starting voltage can be limited, the amplitude of the voltage and current of the circuit does not reach excessive values, and the operating life is relatively long. Inexpensive parts can be used.
Japanese Unexamined Patent Publication No. 6-1888091

  In the electrodeless discharge lamp lighting device, in order to efficiently transmit the high-frequency electromagnetic field generated by the induction coil to the electrodeless discharge lamp, the induction coil needs to be disposed in the vicinity of the electrodeless discharge lamp. For this reason, the induction coil receives a heat from the plasma during lighting of the electrodeless discharge lamp and becomes a high temperature state. As a result, the inductance value of the induction coil may decrease due to the characteristics of the magnetic material disposed to further increase the high-frequency electromagnetic field generated by the induction coil. In addition, the power conversion circuit may receive its own loss or heat from the electrodeless discharge lamp, and the inductance value of the inductive element in the power conversion circuit may decrease.

  In such a state, when the electrodeless discharge lamp is turned off and re-ignition is performed in a short period in a high temperature state, the resonance of the resonance circuit including the power conversion circuit and the induction coil is caused by the change in the inductance value. The frequency may increase. For this reason, at the operating frequency of the power conversion circuit set in the normal state, re-ignition is started in a state where the voltage output to the induction coil is excessive. The excessive voltage generated in this way becomes a pulse-like high voltage, which causes excessive stress on the power conversion circuit, the induction coil, etc., and may shorten the life of the electrodeless discharge lamp lighting device.

  In addition, when the temperature of the induction coil or inductive element in the power conversion circuit is high, the current value that can be passed through the induction coil or inductive element is limited, and if a current value higher than that is passed, saturation of the magnetic flux occurs. The inductance value decreases. This occurs after the applied voltage exceeds a certain value after the operation of applying a voltage to the induction coil is started, and excessive stress accompanying an increase in the resonance frequency is generated as described above.

  Thus, an excessive voltage may be generated in two modes at the start of ignition and when the voltage applied to the induction coil becomes equal to or higher than a certain value after the start of ignition. This excessive voltage becomes a pulsed high voltage, which may cause excessive stress on the power conversion circuit, the induction coil, and the like, and may shorten the life of the electrodeless discharge lamp lighting device.

  The above-described conventional example (Patent Document 1) has a mechanism for increasing the voltage output to the induction coil in a sweeping manner with time and holding it when the voltage is constant. In such a case, in order to stabilize the output voltage to the induction coil, a feedback system having a relatively large time constant is used to design the system with an emphasis on system stability.

  However, as described above, the pulsed high voltage generated by the decrease in the inductance value reaches the high voltage in a very short period. Therefore, the feedback system that emphasizes the stability described above can suppress the pulsed high voltage. Have difficulty.

  Further, in addition to a feedback system having a large time constant that places importance on stability, it is conceivable that a feedback system having a small time constant corresponding to a pulsed high voltage is simply connected in parallel. However, while the time constant for changing the voltage in a sweeping manner has a time constant of 0.1 millisecond to millisecond, the time constant of the pulsed high voltage becomes a time constant in units of 1 microsecond, which is a large time constant. With the difference. When time constant systems corresponding to the respective systems are simply connected in parallel, the difference between the time constants causes a situation in which other systems interfere with the normal operation of the respective systems. For example, when a feedback system for suppressing a pulsed voltage is operated in response to a normal sweep-like voltage rise, the sweep-like voltage rise is suppressed, and it operates for a long time at a voltage at which the lamp does not light. Does not light up, or excessive stress is applied to the power conversion circuit. In order to avoid this situation, if the feedback system for suppressing the pulse voltage is weakened, when the pulse voltage is generated, sufficient deterrent does not work and it is applied to the induction coil and power conversion circuit. There is a problem of increased stress.

  The present invention has been made in view of the above problems, and the object of the present invention is to have a simple configuration, a low stress on the power conversion circuit, the resonance circuit, and the induction coil, and a reliable electrodeless discharge lamp. It is an object of the present invention to provide an inexpensive and simple electrodeless discharge lamp lighting device that can be started automatically.

According to the present invention, in order to solve the above problem, as shown in FIG. 1, an induction coil 2 wound in the vicinity of an electrodeless discharge lamp 1 and power conversion for supplying power to the induction coil 2 Circuit 3, power supply circuit 4 for supplying power to power conversion circuit 3, drive circuit 5 for driving switching elements Q1, Q2 of power conversion circuit 3, voltage of induction coil 2 or power conversion circuit 3 Alternatively, the drive frequency of the switching elements Q1 and Q2 by the drive circuit 5 is changed according to the output values of the detection means 6 for detecting the current, the instruction value generation means 7, and the detection means 6 and the instruction value generation means 7. In the electrodeless discharge lamp lighting device comprising the control circuit 8, the control circuit 8 includes a plurality of feedback systems FB1, FB2, FB3,... With different time constants between the drive circuit 5 and the detection means 6. Comprising a bn, the selection means 9 for selecting a plurality of the feedback system, the selection means 9 selects the feedback system in accordance with the state at the start of the electrodeless discharge lamp 1, the applied voltage of the induction coil 2 is high When the first feedback system is selected, the second feedback system having a larger time constant than the first feedback system is selected when the applied voltage of the induction coil 2 is low. is there.

  According to the first aspect of the present invention, a plurality of feedback systems having different time constants and a selection means for selecting the plurality of feedback systems are provided, and the feedback system is selected in accordance with the starting state of the electrodeless discharge lamp. As a result, a feedback system with a different time constant should be used depending on the situation, such as when a pulsed high voltage is applied to the induction coil or when it is desired to increase the voltage applied to the induction coil in a sweeping manner. It is possible to apply an appropriate voltage to the induction coil and to reliably turn on the electrodeless discharge lamp, and to reduce stress on the induction coil and the power conversion circuit. A high electrodeless discharge lamp lighting device can be obtained.

Further, according to the invention of claim 1, the applied voltage of the induction coil to select a large feedback system time constant when low, it is so arranged to select a smaller feedback system time constant when the applied voltage of the induction coil is higher When the induction coil application voltage with a sufficient margin for current and voltage application stresses such as circuit elements of the electrodeless discharge lamp lighting device is low, the induction coil application voltage can be made smoother by performing control with more emphasis on stability. If the induction coil applied voltage with a small margin for current / voltage application stress is high, increase the response speed, catch the signs of small induction coil application voltage rise and suppress it, and apply the current / voltage applied stress. It is possible to reduce the increase in As a result, the stress applied to the circuit element of the electrodeless discharge lamp lighting device can be reduced, so that the element resistance can be reduced, and an inexpensive and small electrodeless discharge lamp lighting device can be obtained. .

According to the second aspect of the present invention, the contribution ratio, which is the ratio of the driving frequency to the input of the feedback system, is set larger in the feedback system having a small time constant than in the feedback system having a large time constant. When operating a feedback system with a small time constant, it is possible to increase the rate at which the drive frequency is changed, and to respond to an increase in applied stress of a smaller voltage or current. It becomes.

According to the invention of claim 3 , the feedback system can be substantially selected by changing the contribution ratio of each feedback system. In other words, by increasing the contribution ratio of a certain feedback system, the feedback time constant of the entire system substantially approaches the time constant of the feedback system, so the same effect as switching a feedback system with a different time constant Is obtained. Further, it is not necessary to switch the feedback system by a switching element or the like, the waveform disturbance due to discontinuous control at the time of switching can be prevented, and a highly stable electrodeless discharge lamp lighting device can be obtained.

  FIG. 1 shows a preferred embodiment of the present invention. The lighting device includes an electrodeless discharge lamp 1 made of a translucent material in which a discharge gas is sealed, an induction coil 2 wound in the vicinity of the electrodeless discharge lamp, and switching elements Q1 and Q2. A power conversion circuit 3 that supplies power to the induction coil 2, a power supply circuit 4 that supplies power to the power conversion circuit 3, a drive circuit 5 that drives the switching elements Q1 and Q2, and the induction coil 2 or the power Detection means 6 for detecting the voltage or current of the conversion circuit 3, instruction value generation means 7, and switching elements Q 1 and Q 2 of the drive circuit 5 according to the output values of the detection means 6 and the instruction value generation means 7. In the electrodeless discharge lamp lighting device comprising the control circuit 8 for changing the driving frequency, the control circuit 8 has a plurality of feeds whose time constants increase from 1st to nth. And a selection means 9 for selecting any one of the feedback systems FB1 to FBn is provided, and the selection means 9 selects the feedback system when the electrodeless discharge lamp 1 is started. Features.

  As described above, the control circuit 8 includes the feedback system in which the time constant increases from the first to the nth, and the selection unit 9 that selects any one of the feedback systems FB1 to FBn is provided. Feedback with different time constants depending on the state in which a pulsed high voltage is applied to the voltage applied to the induction coil 2 or the voltage applied to the induction coil 2 is to be changed in a sweeping manner. The system can be selected and used, and an appropriate voltage can be applied to the induction coil 2 so that the electrodeless discharge lamp 1 can be reliably turned on, and the induction coil 2 and the power conversion circuit 3 are applied. Stress can be reduced, and a highly reliable electrodeless discharge lamp lighting device can be obtained.

  In FIG. 1, the power conversion circuit 3 includes a switching circuit 10 and a resonance circuit 11. The switching circuit 10 is composed of a series circuit of switching elements Q1 and Q2, and the DC voltage of the power supply circuit 4 is applied to both ends. Switching elements Q1 and Q2 are alternately turned on and off by drive circuit 5. A parallel circuit of a capacitor C2 and an induction coil 2 is connected to both ends of the switching element Q2 via a series circuit of an inductor L1 and a capacitor C1. Induction coil 2 acts as inductor L2. The configuration of the resonance circuit 11 is not limited to that illustrated. When the switching elements Q1 and Q2 are alternately turned on and off, the DC voltage from the power supply circuit 4 is converted into a rectangular wave-like high-frequency voltage and applied to the resonance circuit 11, and the sinusoidal wave is generated by the LC resonance action of the resonance circuit 11. The high frequency AC voltage is applied to the induction coil 2.

  Here, it is assumed that the drive circuit 5 in FIG. 1 has an oscillation circuit using a capacitor charge / discharge circuit and a voltage comparator, for example. That is, the capacitor is charged with a predetermined charging time constant, and when the voltage of the capacitor reaches the first reference voltage, the output of the voltage comparator is inverted. Thereafter, the capacitor is discharged with a predetermined discharge time constant, and when the voltage of the capacitor reaches a second reference voltage lower than the first reference voltage, the output of the voltage comparator is inverted again. Thereafter, the operation of charging the capacitor with a predetermined time constant is repeated. Thereby, a rectangular wave voltage is obtained at the output of the voltage comparator. Switching elements Q1 and Q2 are alternately turned on and off by this rectangular wave voltage.

  Although the switching elements Q1 and Q2 are constituted by MOSFETs, a bipolar transistor having a reverse diode connected in parallel may be used. A current detection resistor Rs is inserted in series on the source side of the switching element Q2 on the low potential side. The current detection resistor Rs is made of a minute resistance, and causes a voltage drop corresponding to the current flowing between the main electrodes (drain / source) of the switching element Q2. The detection means 6 detects the switching current of the power conversion circuit 3 by amplifying the voltage across the current detection resistor Rs with an operational amplifier or the like.

  The feedback system FB1 is a low-pass filter circuit such as a CR integration circuit, for example, and obtains an average value by time-integrating the detection output of the detection means 6 according to the time constant. When a feedback system FBn having a large time constant is used, the average value does not increase or decrease immediately even if the detected value increases or decreases, and the response speed of the control becomes slow. When the feedback system FB1 with a small time constant is used, the average value immediately increases and decreases as the detected value increases and decreases, so that the control response speed increases.

  The instruction value generating means 7 is a reference voltage source, and is, for example, a circuit that generates a reference voltage by dividing the control power supply voltage by a constant voltage and then dividing it by a voltage dividing resistor. The reference voltage output from the instruction value generating means 7 may be increased or decreased for dimming control. Further, it may be changed in a sweep shape as it shifts from starting to stable lighting.

  The output of the instruction value generation means 7 is input to the comparison means 12 of the control circuit 8 as a control target. A voltage obtained by averaging the output value of the detection means 6 by the feedback system is input to the other input of the comparison means 12, and charging / discharging of the capacitor of the drive circuit 5 is performed so as to coincide with the instruction value of the instruction value generation means 7. The ON / OFF frequency of the switching elements Q1, Q2 is changed by changing the time constant or the first or second reference voltage. As the comparison means 12, a differential amplifier such as an operational amplifier may be used. In this case, the feedback systems FB1 to FBn may be external CR elements (for example, feedback impedance) of the differential amplifier.

  In the example of FIG. 1, the detection means 6 detects the current flowing through the main electrode of the switching element Q2. However, if the voltage or current of the induction coil 2 or the power conversion circuit 3 is detected, the detection portion 6 The detection method is not limited.

  For example, in order to detect the current of the resonance circuit 11, a current transformer is inserted in series into an inductance element or a capacitance element to be detected, and the current is detected. Alternatively, a current is detected by connecting a minute resistor in series and amplifying the voltage across the resistor with an operational amplifier. In addition, in order to detect the voltage of the resonance circuit 11, for example, a high-impedance resistance voltage dividing circuit is connected in parallel to an inductance element or a capacitance element to be detected, and the voltage is detected. Alternatively, a secondary winding may be provided in the inductance element, and the voltage may be detected by the secondary winding output.

  Further, the configuration of the switching circuit 10 is not limited to a half bridge circuit in which two switching elements Q1 and Q2 that are alternately turned on and off are connected in series, and a single-switch type switching circuit may be used. A configuration may be used in which a full-bridge circuit is configured by the switching elements and a DC power supply voltage is converted into a high-frequency AC voltage by alternately turning on and off the diagonal switching elements.

  Further, as the power supply circuit 4, in the circuit of FIG. 1, the commercial AC power supply Vs is full-wave rectified by the rectifier bridge DB, and the direct current is supplied to the smoothing capacitor C3 via the boost chopper circuit 13 including the inductor L3, the switching element Q3, and the diode D3. A configuration for obtaining a voltage is used. In the figure, reference numeral 14 denotes a power factor correction control circuit, which operates to reduce the idle period of the input current from the commercial AC power supply Vs by turning on and off the switching element Q3 of the boost chopper circuit 13 at a high frequency. Of course, the configuration of the power supply circuit 4 is not limited to the configuration illustrated in FIG. 1. In addition to the step-down chopper circuit and the step-up / step-down chopper circuit, a circuit in which batteries are connected in series or in parallel, or any type other than the switching type A power supply circuit may be used.

It illustrates a cross-sectional structure of the electrodeless discharge lamp 1 in FIG. This electrodeless discharge lamp 1 has a hollow cavity with a concave section opened downward at the center of a substantially spherical bulb 20 made of a translucent material in which a discharge gas containing at least mercury and a rare gas is enclosed. Part 21. The hollow portion 21 houses the induction coil 2 that supplies a high-frequency electromagnetic field to the discharge gas. Further, a magnetic material around which the induction coil 2 is wound is provided with a cylindrical core 22 and a heat dissipating member 23 that is disposed inside the core 22 and is made of a heat conductive material that contacts the core 22. A phosphor 24 is applied to the inside of the bulb 20. The phosphor 24 converts ultraviolet rays generated by vaporized mercury discharge into visible light.

The electrodeless discharge lamp lighting device of FIG. 1 can be used as a lighting device as shown in FIG. 7 , for example. Since the electrodeless discharge lamp 1 is generally driven at a high frequency of several tens of MHz, it is covered with a shield cover 25 such as a metal mesh in order to absorb radiation noise from the lamp. 26 is a base for supporting the induction coil 2, and 27 is a lighting circuit.

Hereinafter, various embodiments of the present invention will be described. Since the basic configuration of each embodiment is the same as that described in FIGS. 1, 6 , and 7 , the basic functions are substantially the same. These parts are denoted by the same reference numerals, and overlapping description of common parts is omitted.

(Example 1)
FIG. 2 shows a first embodiment of the present invention. The present embodiment corresponds to the configuration of the first aspect , and the control circuit 8 includes feedback systems FB1 to FB3 whose time constants increase from the first to the third, and these FB1 to FB3. The selection unit 9 selects the first feedback system FB1 when the induction coil application voltage is high, and the selection unit 9 selects the second feedback system when the induction coil application voltage is low. When FB2 is selected and the induction coil applied voltage is even lower, the third feedback system FB3 is selected.

  As a result, when the induction coil application voltage with sufficient margin for current and voltage application stresses such as circuit elements of the electrodeless discharge lamp lighting device is low, the induction coil application voltage is reduced by performing control with more emphasis on stability. It can be changed smoothly. In addition, when the applied voltage of the induction coil with a small margin to the applied stress of current / voltage is high, the response speed is increased, the sign of a small increase of the applied voltage of the induction coil is captured and suppressed, and the stress of applied current / voltage is suppressed. The increase can be reduced.

  According to this embodiment, the peak of current stress and voltage stress applied to the circuit element of the electrodeless discharge lamp lighting device can be reduced, so that the element resistance is reduced, and an inexpensive and small electrodeless discharge is achieved. An electric lamp lighting device can be obtained.

  In the illustrated example, the selection means 9 is switched using the magnitude of the indication value output from the indication value generation means 7, but the induction coil applied voltage is directly detected and selected according to the detection result. The means 9 may be switched.

(Example 2)
FIG. 3 shows a second embodiment of the present invention. The present embodiment corresponds to the configuration of the second aspect , and the control circuit 8 includes feedback systems FB1 to FB3 whose time constants increase from the first to the third, and these FB1 to FB3. The selection means 9 for selecting any one of the feedback systems is provided, and the feedback system having a smaller time constant is set to have a higher contribution rate than the feedback system having a larger time constant.

  Here, the contribution ratio is an input to each feedback system when the drive frequency of the switching elements Q1 and Q2 of the drive circuit 5 is changed according to the output values of the detection means 6 and the instruction value generation means 7. As a result, the ratio of changing the driving frequency is shown. The greater the contribution ratio, the greater the change in drive frequency for a slight change in input.

In FIG. 3 , the contribution rate m of each feedback system FB1 to FB3 is schematically shown as “× m”. For example, when the contribution rate of the feedback system FB3 having a large time constant is set to 1 time, feedback having a small time constant is performed. The contribution ratio of the system FB2 is set to double, and the contribution ratio of the feedback system FB1 having a smaller time constant is set to triple. Although the specific numerical value of the contribution rate is not limited to this, in short, the feedback system with a small time constant is set to have a larger contribution rate than the feedback system with a large time constant.

  As a result, at the time of operation of a feedback system with a small time constant that requires a quick response, the rate of change of the drive frequency can be increased, and it is possible to cope with the suppression of the increase in applied stress. An electrodeless discharge lamp lighting device can be obtained.

The detection means 6 may detect the current flowing through the switching element Q2 of the switching circuit 10 as shown in FIG. 1, may detect the current flowing through the induction coil 2, or the voltage of the inductor L1. may be detected, may be detected voltage applied to the induction coil 2, as shown in FIG. In each of the following embodiments, the detection means 6 may detect either the voltage or current of the switching circuit 10, the resonance circuit 11, or the induction coil 2, and the detection location and detection method are not limited. In each circuit of FIGS. 1 and 2 , the configuration of the detection means 6 is merely an example, and is not limited to the illustrated configuration.

(Example 3)
FIG. 4 shows a third embodiment of the present invention. The present embodiment corresponds to the configuration of the third aspect , and the control circuit 8 includes feedback systems FB1 to FB3 whose time constants increase from the first to the third, and these FB1 to FB3. As the selection means 9 for selecting any one of the feedback systems, means for changing the contribution ratio of the feedback system is provided.

  Here, the contribution ratio is an input to each feedback system when the drive frequency of the switching elements Q1 and Q2 of the drive circuit 5 is changed according to the output values of the detection means 6 and the instruction value generation means 7. As a result, the ratio of changing the driving frequency is shown.

FIG. 4 schematically shows the contribution rates of the feedback systems FB1 to FB3. For example, when the contribution rate of the feedback system FB3 having a large time constant is m3 times, the contribution rate of the feedback system FB2 having a small time constant is The contribution rate of the feedback system FB1 having a smaller m2 time constant is set to m1 times.

  The feedback system can be substantially selected by changing the contribution ratios m1 to m3 of the feedback systems FB1 to FB3. In other words, by increasing the contribution ratio of a certain feedback system, the feedback time constant of the entire system substantially approaches the time constant of the feedback system, so the same effect as switching a feedback system with a different time constant Is obtained. Further, it is not necessary to switch the feedback system by a switching element or the like, the waveform disturbance due to discontinuous control at the time of switching can be prevented, and a highly stable electrodeless discharge lamp lighting device can be obtained.

Example 4
FIG. 5 shows a fourth embodiment of the present invention. The present embodiment is a more specific example of the third embodiment. The first feedback system FB1 is a series circuit of a resistor R1 and a Zener diode ZD1, and the second feedback system FB2 is a series circuit of a resistor R2 and a Zener diode ZD2. The third feedback system FB3 includes a series circuit of a resistor R3 and a Zener diode ZD3, and these are connected in parallel to constitute the selection means 9.

  Here, the Zener voltages of the Zener diodes ZD1, ZD2, and ZD3 increase in the order of VZD1 <VZD2 <VZD3, and the selection means 9 selects the first feedback system FB1 when the induction coil applied voltage is low, When the induction coil applied voltage is high, the second feedback system FB2 is selected, and when the applied voltage is further increased, the third feedback system FB3 is selected.

  Further, the relationship between the resistance value R1 of the resistor R1 of the first feedback system FB1, the resistance value R2 of the resistor R2 of the second feedback system FB2, and the resistance value R3 of the resistor R3 of the third feedback system FB3 is expressed as R1> R2 > R3.

  Thereby, when the induction coil applied voltage is low, the first feedback system FB1 is selected, and the entire time constant becomes a large value. When the voltage applied to the induction coil rises, the current flows through the resistor R2 exceeding the Zener voltage of the Zener diode D2 of the second feedback system FB2, the overall time constant is lowered, and the responsiveness is accelerated. When the voltage applied to the induction coil is further increased, a current flows through the resistor R3 exceeding the Zener voltage of the Zener diode ZD3 of the third feedback system FB3, the entire time constant is further decreased, and the response is further accelerated. During stable lighting, the contribution rate of the first feedback system FB1 is smaller than the contribution rate of the second feedback system FB2, and the contribution rate of the second feedback system FB2 is smaller than the contribution rate of the third feedback system FB3.

In the present embodiment, as the detection means 6, as shown in FIG. 2 , a series circuit of capacitors C21 and C22 is connected in parallel to the induction coil 2, and a voltage obtained by substantially dividing the voltage applied to the induction coil is detected. However, as long as it is a detection value that can reflect the voltage applied to the induction coil, the voltage or current at other locations may be detected.

  According to the configuration of the present embodiment, the time constant of the feedback system can be switched according to the applied voltage of the induction coil even though the circuit configuration is simple, and when the applied voltage of the induction coil is low, the electrodeless discharge lamp Since there is a margin in the applied stress of current and voltage for the circuit elements of the lighting device, etc., the feedback coil applied voltage can be changed smoothly by increasing the time constant of the feedback system and performing control with more emphasis on stability. Can do. In addition, when the induction coil applied voltage is high, since there is less margin in the application stress of current and voltage such as circuit elements, the response speed is increased, the sign of a small increase in the induction coil applied voltage is captured and suppressed, It is possible to reduce an increase in current / voltage application stress. As a result, the stress applied to the circuit element of the electrodeless discharge lamp lighting device can be reduced, so that the element resistance can be reduced, and an inexpensive and small electrodeless discharge lamp lighting device can be obtained. .

  INDUSTRIAL APPLICABILITY The present invention can be used as, for example, an outdoor or high-level lighting device as a long-life lighting device with high efficiency and low lamp replacement frequency.

It is a circuit diagram which shows the basic composition of this invention. It is a circuit diagram of Example 1 of the present invention. It is a circuit diagram of Example 2 of the present invention. It is a circuit diagram of Example 3 of the present invention. It is a circuit diagram of Example 4 of the present invention. It is sectional drawing which illustrates the structure of the electrodeless discharge lamp used for the non-discharge discharge lamp lighting device of this invention. It is sectional drawing which illustrates the structure of the illuminating device using the electrodeless discharge lamp lighting device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrodeless discharge lamp 2 Induction coil 3 Power conversion circuit 4 Power supply circuit 5 Drive circuit 6 Detection means 7 Instruction value generation means 8 Control circuit 9 Selection means FBn Feedback system

Claims (4)

Driving an induction coil wound in the vicinity of an electrodeless discharge lamp, a power conversion circuit that supplies power to the induction coil, a power supply circuit that supplies power to the power conversion circuit, and a switching element of the power conversion circuit Driving circuit, detecting means for detecting the voltage or current of the induction coil or the power conversion circuit, instruction value generating means, and switching by the driving circuit according to the output values of the detecting means and the instruction value generating means In the electrodeless discharge lamp lighting device comprising a control circuit for changing the drive frequency of the element, the control circuit includes a plurality of feedback systems having different time constants between the drive circuit and the detection means, and the plurality of feedback systems. a selection means for selecting, said selecting means selects a feedback system in accordance with the state at the start of the electrodeless discharge lamp, induction carp Characterized in that when the applied voltage is high, it selects the first feedback system, when the applied voltage of the induction coil is low which is adapted to select the second feedback system having a large time constant than the first feedback system An electrodeless discharge lamp lighting device. Contribution ratio is a ratio of driving frequency to the input of the feedback system, discharge electrodeless according to claim 1, characterized in that it is set larger in a small feedback system having a time constant than larger feedback system time constant Electric light lighting device. It said selection means, the electrodeless discharge lamp lighting device according to claim 1 or 2, characterized in that changing the contribution ratio is a ratio of driving frequency to the input of the feedback system. An illuminating device comprising the electrodeless discharge lamp lighting device according to any one of claims 1 to 3 .

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