JP2009032526A - Electrodeless discharge lamp lighting device, and luminaire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrodeless discharge lamp lighting device capable of dimly light an electrodeless discharge lamp in a stable state even when the temperature is low, and a luminaire. <P>SOLUTION: This electrodeless discharge lamp lighting device is equipped with a power conversion circuit 9 for outputting a high frequency voltage by receiving power supply from a dc power supply, an induction coil 5 connected between the output ends of the power conversion circuit 9 and disposed close to the electrodeless discharge lamp 6 in which a discharge gas is filled in a bulb, a frequency control circuit 12 for flickering the electrodeless discharge lamp 6 by alternately switching a lighted period for setting the magnitude of the voltage between both ends of the induction coil 5 so as to light the electrodeless discharge lamp 6 and a non-lighted period for setting the magnitude so as not to light it, and an ambient temperature detecting circuit 44 which is a temperature detecting means to detect the ambient temperature of the electrodeless discharge lamp 6. A time occupancy rate lowering means composed of a PWM oscillating circuit 13 and an on-duty setting circuit 41 decreases a restrike starting time occupancy rate by raising the lighted period when the temperature detected by the ambient temperature detecting circuit 44 is low. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

2. Description of the Related Art Conventionally, as an electrodeless discharge lamp lighting device for lighting an electrodeless discharge lamp, an apparatus that performs light control by causing the electrodeless discharge lamp to blink is proposed (Patent Document 1). Here, the electrodeless discharge lamp lighting device disclosed in Patent Document 1 includes a power conversion circuit that converts the output of a DC power source into a high-frequency voltage and supplies it to an induction coil adjacent to the electrodeless discharge lamp, As shown in FIG. 17, the voltage applied between the both ends of the induction coil from the power conversion circuit is cycled between a lighting period Ton that is set to a magnitude at which the electrodeless discharge lamp is lit and a non-lighting period Toff that is set to a magnitude that is not lit. The electrodeless discharge lamp is caused to blink by switching alternately, and light control is performed by adjusting the ratio of the lighting period Ton in one cycle T (= Ton + Toff) of the blinking operation.
JP 2000-353600 A

  However, in the electrodeless discharge lamp lighting device disclosed in Patent Document 1, when the ambient temperature of the electrodeless discharge lamp is equal to or lower than a specified temperature lower than room temperature (for example, 25 ° C.), Since the ignition voltage is generated, the re-ignition start time becomes longer. Moreover, when the resonance circuit included in the power converter circuit has a large Q value that is lower than the specified temperature, the operating frequency is swept at the time of re-ignition start in order to absorb variations in the high-frequency voltage applied across the induction coil. Therefore, it is necessary to increase the high-frequency voltage, and accordingly, the re-ignition start time becomes longer. Further, when the ambient temperature of the electrodeless discharge lamp is low (for example, −20 ° C.), since the plasma impedance changes greatly, the voltage between both ends of the induction coil after re-ignition is also greatly reduced. For this reason, as shown in FIG. 18, even if the re-ignition voltage decreases, the high-frequency voltage across the induction coil further decreases, and as a result, the re-ignition start time becomes longer. For these reasons, if the re-ignition start time becomes longer, the occupancy ratio of the time required for re-ignition start of the electrodeless discharge lamp in the lighting period Ton (hereinafter referred to as the re-ignition start time occupancy ratio) increases. There is a problem that lighting of the discharge lamp tends to be unstable. In the above electrodeless discharge lamp lighting device, since the lighting period Ton becomes shorter as the dimming ratio decreases, the re-ignition start time occupancy increases and the operation tends to become unstable. The lower the temperature is, the easier the operation of the electrodeless discharge lamp becomes unstable.

  The present invention has been made in view of the above-mentioned reasons, and an object thereof is to provide an electrodeless discharge lamp lighting device and a lighting fixture capable of stably dimming and lighting an electrodeless discharge lamp even at low temperatures. There is to do.

The invention according to claim 1 is a power conversion circuit for receiving a power supply from a DC power supply and outputting a high-frequency voltage, and is connected between the power conversion circuit including at least a switching element and a resonance circuit, and an output terminal of the power conversion circuit And an induction coil disposed in the vicinity of an electrodeless discharge lamp in which a discharge gas is enclosed in a bulb, and an operating frequency of the power conversion circuit is controlled, and the high-frequency voltage is set to a size at which the electrodeless discharge lamp is lit. A frequency control circuit that causes the electrodeless discharge lamp to blink by alternately switching between a lighting period to be set and a non-lighting period set to a size that does not light, and a temperature detection means that detects an ambient temperature of the electrodeless discharge lamp, Occupancy rate of time required for re-ignition start of the electrodeless discharge lamp in the lighting period in the blinking operation when the temperature detected by the temperature detecting means is not more than a specified temperature lower than normal temperature According to the present invention, there is provided a time occupancy reduction means for reducing a certain re-ignition start time occupancy ratio. According to the present invention, the temperature detected by the temperature detection means for detecting the ambient temperature of the electrodeless discharge lamp is lower than the normal temperature. When the temperature is lower than the specified temperature, the time occupancy reduction means reduces the re-ignition start time occupancy, so that the electrodeless discharge lamp can be stably dimmed even at low temperatures. .

According to a second aspect of the present invention, in the first aspect of the invention, the time occupancy reduction means increases the re-ignition start time occupancy by increasing a ratio of the lighting period to the non-lighting period in the blinking operation. According to this invention, when the ambient temperature of the electrodeless discharge lamp is equal to or lower than the specified temperature, the time occupancy reduction means is configured to turn on the lighting for the non-lighting period in the blinking operation. Since the ratio of the period is increased, the rapid decrease in the light output of the electrodeless discharge lamp accompanying the temperature decrease can be mitigated, and the deviation between the light control ratio at normal temperature and the light control ratio below the specified temperature is suppressed. can do. Further, since the non-lighting period is shortened by lengthening the lighting period, the diffusion of ions in the bulb during the non-lighting period is reduced, thereby reducing the re-ignition voltage, and the low temperature Lighting of the electrodeless discharge lamp can be stabilized. Moreover, since the high frequency power supplied from the power conversion circuit to the induction coil is increased by lengthening the lighting period, the time until the electrodeless discharge lamp is warmed is shortened. It is possible to shorten the time until the lighting is stabilized.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, there is provided a PWM oscillation circuit that applies a PWM signal to the frequency control circuit, and the frequency control circuit is based on a PWM signal from the PWM oscillation circuit. The operating frequency is controlled, and the time occupancy reduction means reduces the re-ignition start time occupancy by reducing the frequency of the PWM signal.

  According to the present invention, since the time occupancy reduction means reduces the frequency of the PWM signal applied to the frequency control circuit, the re-ignition start is performed without increasing the high-frequency power supplied to the electrodeless discharge lamp. Since the time occupancy can be reduced, even when the ratio of the lighting period to the non-lighting period in the blinking operation is reduced for the purpose of reducing the high-frequency power or deepening the dimming, the electrodeless discharge lamp It becomes possible to stabilize lighting.

According to a fourth aspect of the present invention, in the first to third aspects of the invention, the frequency control circuit sets the operating frequency in the lighting period in the vicinity of a resonance frequency of a resonance circuit included in the power conversion circuit. According to this invention, since the frequency control circuit sets the operating frequency in the vicinity of the resonance frequency of the resonance circuit, the resonance circuit is caused by variations in component constants of the resonance circuit and changes in the ambient temperature of the power conversion circuit. Even if a frequency shift occurs, the operating frequency is near the peak of the resonance curve when the resonant circuit is lit, so the change in the output of the power conversion circuit due to the shift in the resonant frequency is small, and the electrodeless discharge lamp It is possible to stabilize the lighting and suppress the turning off.

According to a fifth aspect of the present invention, in the first to fourth aspects of the invention, the temperature detecting means detects the ambient temperature by detecting a current flowing through the switching element. The temperature detection means can be housed in the power conversion circuit, and the ambient temperature can be detected even when the electrodeless discharge lamp is installed at a location away from the power conversion circuit.

  According to a sixth aspect of the present invention, in the first to fourth aspects of the present invention, the temperature detecting means detects the ambient temperature with a temperature sensing element.

  According to this invention, it is possible to reduce the size of the temperature detecting means, and it is possible to reduce the cost of parts of the temperature detecting means.

  A seventh aspect of the invention is characterized by comprising the electrodeless discharge lamp lighting device according to any one of the first to sixth aspects.

  According to the present invention, it is possible to provide a lighting fixture capable of stably dimming and lighting an electrodeless discharge lamp even at a specified temperature lower than room temperature.

  The present invention reduces the re-ignition start time occupancy ratio, which is the occupancy ratio of the time required for re-ignition start during the lighting period in the blinking operation even when the ambient temperature of the electrodeless discharge lamp is lower than the specified temperature lower than normal temperature. Therefore, there is an effect that the electrodeless discharge lamp can be stably dimmed even at a low temperature.

(Embodiment 1)
Hereinafter, the electrodeless discharge lamp lighting device of the present embodiment will be described with reference to FIGS.

  As shown in FIG. 1A, the electrodeless discharge lamp lighting device of the present embodiment receives a power supply from an AC power supply AC and outputs a DC voltage VDC, and a power supply from the DC power supply E. The power conversion circuit 9 that outputs the high-frequency voltage Vcoil, the induction coil 5 that is connected between the output terminals of the power conversion circuit 9 and is disposed in the vicinity of the electrodeless discharge lamp 6, and the power conversion circuit 9. Drive circuit 11, a start sweep circuit 12 that controls the switching frequency (hereinafter referred to as an operating frequency) finv of the switching elements Q 3 and Q 4 included in the power conversion circuit 9, and a PWM that inputs the PWM signal Vpwm to the start sweep circuit 12 And an oscillation circuit 13. In the electrodeless discharge lamp lighting device of this embodiment, the lighting circuit 1 is configured by the DC power source E, the power conversion circuit 9, the drive circuit 11, the start sweep circuit 12, and the PWM oscillation circuit 13.

  The DC power source E includes a diode bridge 10 that rectifies the AC power source AC and a boost chopper that boosts the output of the diode bridge 10. Here, in the step-up chopper, a series circuit of an inductor L10 and a switching element Q6 composed of a MOSFET is connected between output terminals of the diode bridge 10, and a series circuit of a diode D10 and a smoothing capacitor C10 is connected between both ends of the switching element Q6. And a control circuit 2 that controls the above-described DC voltage VDC composed of the voltage across the smoothing capacitor C10 by turning on and off the switching element Q6. The diode D10 is connected in a direction in which a current flows from the inductor L10 to the smoothing capacitor C10.

In the power conversion circuit 9, a series circuit of switching elements Q3 and Q4 made of a pair of MOSFETs is connected between the output terminals of the DC power supply E, and the DC voltage VDC from the DC power supply E is switched by the switching elements Q3 and Q4 to generate a high frequency. Convert to voltage. Here, a series circuit of an inductor Ls and a capacitor Cp is connected between the drain and source of the switching element Q4 on the low potential side, and the inductor Ls and the capacitor Cp constitute a resonance circuit. The induction coil 5 is connected between both ends of the capacitor Cp via the capacitor Cs. Here, in the power conversion circuit 9, the switching elements Q3 and Q4 are alternately turned on and off at high frequency by a drive signal from the drive circuit 11 to generate a high frequency voltage, and several tens of kHz to several hundreds of times are applied to the induction coil 5. A high frequency electromagnetic field is generated in the induction coil 5 by flowing a high frequency current of kHz. As shown in FIG. 1B, the drive circuit 11 in which ultraviolet or visible light is generated from the electrodeless discharge lamp 6 by this high frequency electromagnetic field is a series circuit of two resistors R10 and R11 across the constant voltage source Es. Is connected between both ends of the resistor R11, and the voltage controlled oscillator VCO is connected between the Hout terminal and the H-GND terminal at the operating frequency finv according to the input voltage to the input terminal VI, Lout Between the terminal and the L-GND terminal, a rectangular wave drive signal having a phase difference of 180 ° is output. The output voltage of the constant voltage source Es is applied to the input terminal VI of the voltage controlled oscillator VCO by being divided by the resistors R10 and R11, and the input voltage to the input terminal VI starts from the connection point of the resistors R10 and R11. It changes according to the change of the sink current Ivp flowing through the sweep circuit 12. Note that the Hout terminal and the H-GND terminal of the drive circuit 11 are connected between the gate and the source of the switching element Q3, and the Lout terminal and the L-GND terminal are connected between the gate and the source of the switching element Q4.

  The start sweep circuit 12 applies a DC voltage E1 of a DC power source (not shown) to the capacitor C1 via a resistor R1, and a resistor R2 and a series circuit of a switching element Q7 composed of a MOSFET and a resistor R2 are connected to both ends of the capacitor C1. It is connected. The connection point between one end of the capacitor C1 and the resistor R1 is connected to the inverting input terminal of the operational amplifier OP8, and the other end of the capacitor C1 is connected to the non-inverting input terminal of the operational amplifier OP8 through the resistor R122. A resistor R121 is connected between the non-inverting input terminal and the output terminal. The control voltage Vf output from the operational amplifier OP8 is applied to the drive circuit 11 via the resistor R4 and the diode D4. The start sweep circuit 12 and the drive circuit 11 control the operating frequency finv of the power conversion circuit 9, and set the high-frequency voltage Vcoil to a lighting period for setting the electrodeless discharge lamp 6 to turn on and a magnitude for not turning on. The frequency control circuit is configured to cause the electrodeless discharge lamp 6 to blink by alternately switching between non-lighting periods.

  Next, the basic operation of the electrodeless discharge lamp lighting device of the present embodiment will be described with reference to FIGS.

  FIG. 2 shows a resonance curve a at the start of the above-described resonance circuit included in the power conversion circuit 9 and a resonance curve b at the time of lighting. Here, the frequency fe in FIG. 2 is set in the vicinity of the resonance frequency of the resonance circuit so that a high-frequency voltage Vcoil sufficient for starting the electrodeless discharge lamp 6 is applied to the induction coil 5. Further, the frequency fs in FIG. 2 is set such that the induction coil 5 is applied with a high-frequency voltage Vcoil that does not allow the electrodeless discharge lamp 6 to be kept on.

  3A and 3B are explanatory diagrams of the blinking operation. FIG. 3A shows a time change of the high-frequency voltage Vcoil, FIG. 3B shows a time change of the operating frequency finv, and FIG. 3C shows a start sweep circuit. 12 shows the time change of the PWM signal Vpwm input to the circuit 12. The PWM signal Vpwm input to the start sweep circuit 12 has a rectangular wave shape having a maximum value H and a minimum value L. When the PWM signal Vpwm becomes L at time t1, the operating frequency finv gradually changes from the frequency fs to the frequency fe (hereinafter referred to as frequency sweep). Accordingly, the high-frequency voltage Vcoil gradually increases, and the electrodeless discharge lamp 6 is turned on when the maximum voltage Ving1 (hereinafter referred to as the initial ignition voltage) at the time of starting the initial ignition is exceeded. When the operating frequency finv becomes the frequency fe at time t2, the frequency sweep is finished. Next, when the PWM signal Vpwm becomes H at time t3, the operating frequency finv changes to the frequency fs, and accordingly, the high frequency voltage Vcoil becomes lower than the lighting sustain voltage, and the electrodeless discharge lamp 6 is turned off. Next, when the PWM signal Vpwm becomes L at time t4, the frequency sweep of the operating frequency finv starts again, and accordingly, the high-frequency voltage Vcoil gradually increases, and the maximum voltage Ving2 (hereinafter referred to as re-start) at the time of re-ignition start. The electrodeless discharge lamp 6 is turned on when the ignition voltage is exceeded. When the operating frequency finv becomes the frequency fe at time t5, the frequency sweep is finished. Next, when the PWM signal Vpwm becomes H at time t6, the operating frequency finv changes to the frequency fs, and accordingly, the high frequency voltage Vcoil becomes lower than the lighting sustain voltage, and the electrodeless discharge lamp 6 is turned off. Thereafter, by repeating these series of operations in accordance with the PWM signal Vpwm, the electrodeless discharge lamp 6 performs a blinking operation at the frequency fpwm of the PWM signal Vpwm. Then, by varying the on-duty of the PWM signal Vpwm, the time ratio between the lighting period Ton and the non-lighting period Toff of the electrodeless discharge lamp 6 can be changed, and the electrodeless discharge lamp 6 can be dimmed.

  As shown in FIG. 3, the re-ignition voltage Vign2 is smaller than the initial ignition voltage Vign1, but this is due to the presence of ions remaining in the bulb of the electrodeless discharge lamp 6. In addition, the operating frequency finv of the power conversion circuit 9 is set to several tens kHz to several hundreds kHz in order to reduce the cost of the apparatus, and the frequency fpwm of the PWM signal Vpwm is set to 100 Hz to several kHz so as not to flicker the human eye. Set to

  By the way, the electrodeless discharge lamp lighting device of this embodiment includes temperature detection means for detecting the ambient temperature of the electrodeless discharge lamp 6, and the PWM oscillation circuit 13 generates the PWM signal Vpwm based on the output of the temperature detection means. Change the on-duty.

  Here, in the PWM oscillation circuit 13 described above, the on-duty of the PWM signal Vpwm changes according to the resistance value of the resistor connected to the input terminal 46. An on-duty setting circuit 41 as shown in FIG. 1C is connected to the input terminal 46. The on-duty setting circuit 41 selectively connects a temperature-sensitive resistor Rth or resistor R45 including a temperature-sensitive element (for example, a thermistor) to the input terminal 46 via the switching element Q42. The switching element Q42 is controlled based on the output of the ambient temperature detection circuit 44, which is a temperature detection means for detecting the ambient temperature of the electrodeless discharge lamp 6, and the temperature detected by the ambient temperature detection circuit 44 is a normal temperature (for example, FIG. As shown in a), when the electrodeless discharge lamp 6 is fully lit, when the temperature is lower than a specified temperature (for example, 0 ° C.) lower than 25 ° C. at which the light output is maximized, the temperature-sensitive resistor Rth is connected. Here, the resistance value of the temperature-sensitive resistor Rth changes according to the ambient temperature of the electrodeless discharge lamp 6. Then, the on-duty of the PWM signal Vpwm output from the PWM oscillation circuit 13 decreases as the ambient temperature decreases when the ambient temperature of the electrodeless discharge lamp 6 is equal to or lower than the specified temperature. Then, as shown in FIG.4 (b), the ratio (henceforth a lighting period occupation rate) which the lighting period Ton occupies in one cycle in the blinking operation | movement of the electrodeless discharge lamp 6 increases. Here, if it is assumed that the cycle of the blinking operation is constant, the non-lighting period Toff becomes shorter as the lighting period occupation ratio increases, so that the time ratio of the lighting period Ton to the non-lighting period Toff is Will rise. Thereby, by setting the specified temperature appropriately, the light output suddenly decreases below the specified temperature lower than the normal temperature as shown by the ambient temperature dependency of the light output at the time of dimming in FIG. Can be relieved. Here, the ambient temperature detection circuit 44 may use a temperature sensing element (for example, a thermistor). For example, an integrated circuit called M62212FP manufactured by Renesas Technology may be used as the PWM oscillation circuit 13 described above, and the FB terminal of the integrated circuit may be used as the input terminal 46 described above.

  As the on-duty setting circuit 41, as shown in FIG. 7, a series circuit of a resistor R53 and a switching element (for example, MOSFET) Q54 is connected to an input terminal 46, and a resistor R52 is connected to both ends of the series circuit. It may be a thing. Here, the switching element Q54 is controlled based on the output from the temperature detecting means 44 for detecting the ambient temperature of the electrodeless discharge lamp 6, and the temperature detecting means 44 is connected to the direct current from the constant voltage source E55 as shown in FIG. The voltage is divided by the temperature sensitive resistor Rth and the resistor R56 and output to the switching element Q54. When the temperature detected by the temperature detecting means 44 is equal to or higher than the specified temperature, the switching element Q54 is turned on to change the resistance value of the resistor connected to the input terminal 46 of the PWM oscillation circuit 13. Then, the on-duty of the PWM signal Vpwm decreases, the lighting period occupation ratio increases, and the time ratio of the lighting period Ton of the electrodeless discharge lamp 6 increases.

Next, the operation at normal temperature and the operation at low temperature of the electrodeless discharge lamp lighting device of the present embodiment will be described with reference to FIG. FIG. 5A shows an operation waveform at normal temperature, and FIG. 5B shows an operation waveform at low temperature. 5A and 5B show only the envelope of the high-frequency voltage Vcoil between both ends of the induction coil 5. FIG. Among the lighting period Ton, the percentage of time required for the re-ignition starting period T ₁ (hereinafter, referred to as re-ignition starting time occupancy) is electrodeless discharge lamp 6 is whether perform flashing operations and stable There is also an important element of the re-ignition starting time occupancy rate is too large, for example, the influence by ambient temperature change or the like of the electrodeless discharge lamp 6, the electrodeless discharge lamp when the re-ignition starting period T ₁ is fluctuated When the change in the light output of 6 becomes large, the lighting becomes unstable, and in some cases, there is a possibility that it will disappear.

  What should be noted in the present embodiment is that the non-lighting in the blinking operation of the electrodeless discharge lamp 6 is performed when the ambient temperature of the electrodeless discharge lamp 6 is not more than a specified temperature lower than room temperature, as shown in FIGS. The time occupancy reduction means for increasing the time ratio of the lighting period Ton relative to the period Toff includes the PWM oscillation circuit 13 and the on-duty setting circuit 41, and increases the time ratio of the lighting period Ton. As a result, the re-ignition start time occupation ratio is inevitably reduced, and the lighting of the electrodeless discharge lamp 6 can be stabilized.

  Here, when the ambient temperature of the electrodeless discharge lamp 6 is equal to or lower than the specified temperature, the light output of the electrodeless discharge lamp 6 may increase as compared with the normal temperature when the time ratio of the lighting period Ton increases. Is done.

However, normally, as shown in FIG. 6, when the ambient temperature of the electrodeless discharge lamp 6 becomes lower than room temperature, the light output of the electrodeless discharge lamp 6 or the high-frequency power supplied to the electrodeless discharge lamp 6 rapidly decreases. Accordingly, by increasing the time ratio of the lighting period Ton below the specified temperature as described above, the rapid decrease in light output below the specified temperature is moderated, and in the temperature region below the specified temperature. The temperature dependence can be reduced. Accordingly, as shown in FIG. 4 (a), as shown in FIG. 4A, the ratio of the light output during full lighting at normal temperature to the light output during dimming b ₁ / b _{2 with} respect to the ratio b ₁ / b _{2 is} less than the specified temperature. The shift of the ratio c ₁ / c ₂ between the light output and the light output during dimming can be suppressed.

  Here, as a method of reducing the temperature dependency of the light output of the electrodeless discharge lamp 6 in the temperature region below the specified temperature, the drive circuit 11 sets the operating frequency finv in the power conversion circuit 9 at room temperature to the power conversion circuit 9. On the other hand, by setting the operating frequency finv in the lighting period Ton near the resonance frequency below the specified temperature, the operating frequency finv is set below the specified temperature to be higher than that at normal temperature. It can be considered that the voltage Vcoil is controlled to increase.

  However, in this case, since the operating frequency finv in the lighting period Ton is relatively deviated from the resonance frequency at room temperature, there is a problem in that it tends to disappear at room temperature compared to the case where the temperature is lower than the specified temperature. .

  In this regard, in the present embodiment, the operating frequency finv in the lighting period Ton can be set near the resonance frequency even at the specified temperature or lower, so that the temperature of the electrodeless discharge lamp 6 can be stabilized and the temperature equal to or lower than the specified temperature. This is advantageous because the temperature dependence of the light output in the region can be reduced.

  Further, if the frequency fpwm of the PWM signal Vpwm is constant as described above, the non-lighting period Toff is shortened by increasing the time ratio of the lighting period Ton described above. It is possible to reduce the diffusion of ions in the bulb and to reduce the re-ignition voltage Ving2.

  Conventionally, in the electrodeless discharge lamp lighting device, it takes a considerable time until the electrodeless discharge lamp 6 is warmed up after the power is turned on, and it takes a considerable time until the original light output is obtained. In this regard, in the present embodiment, since the high frequency power supplied to the induction coil 5 is increased by increasing the time ratio of the lighting period Ton below the specified temperature as described above, the electrodeless discharge lamp 6 is warmed. As a result, the time from when the power is turned on until the lighting of the electrodeless discharge lamp 6 is stabilized can be shortened.

  In addition, as the electrodeless discharge lamp 6, for example, as shown in FIG. 8, a glass bulb 214 in which a discharge gas such as an inert gas or a metal vapor is sealed is provided, and the bulb 214 is shown in FIG. In some cases, a cavity 25 into which the coupler 319 is inserted is formed, and an exhaust thin tube 28 projects from the bottom of the cavity 25 toward the opening of the cavity 25. Here, the protective film 22 and the phosphor film 23 are applied to the inner wall of the bulb 214 (only a part is shown in the drawing). A base 215 made of a resin material is attached to the bulb neck portion 223 of the electrodeless discharge lamp 6, and the sealing portion 211 of the cavity 25 is provided on the inside thereof. As shown in FIG. 9, the above-described induction coil 5 is provided in the coupler 319, and the induction coil 5 is lit through a connection line 322 derived from the metal case 320 in which the lighting circuit 1 is housed. The circuit 1 is connected.

  The luminaire using the electrodeless discharge lamp lighting device of the present embodiment is configured by being housed together with the electrodeless discharge lamp 6 and the coupler 319 in one casing 116 as shown in FIG. It is configured by being housed together with the electrodeless discharge lamp 6 and the coupler 319 in a casing 126 as shown in FIG. In addition, the lighting fixture shown in FIG. 10 is used outdoors as a security light, for example.

(Embodiment 2)
The electrodeless discharge lamp lighting device of the present embodiment is substantially the same as that in FIG. 1 described above, and only the configuration of the PWM oscillation circuit 13 in FIG. 12 is different. The description of the same configuration as that of the first embodiment is omitted.

  By the way, the electrodeless discharge lamp lighting device of this embodiment is provided with temperature detection means for detecting the ambient temperature of the electrodeless discharge lamp 6, and the PWM signal output from the PWM oscillation circuit 13 based on the output of the temperature detection means. The frequency fpwm is changed.

  Here, the PWM oscillation circuit 13 has a frequency of the PWM signal Vpwm that changes according to the capacitance of the capacitor connected to the input terminal 136. A frequency setting circuit 131 as shown in FIG. 12 is connected to the input terminal 136. The frequency setting circuit 131 selectively connects the capacitor C133 or C134 to the input terminal 136 via the switching element Q132. The switching element Q132 switches the capacitor connected to the input terminal 136 when the detected temperature of the ambient temperature detection circuit 44, which is a temperature detecting means for detecting the ambient temperature of the electrodeless discharge lamp 6, becomes equal to or lower than the specified temperature. Then, the capacitance of the capacitor connected to the input terminal 136 changes, and the frequency of the PWM signal Vpwm increases. Here, the ambient temperature detection circuit 44 may use a temperature sensing element. For example, an integrated circuit called M62212FP manufactured by Renesas Technology may be used as the PWM oscillation circuit 13 described above, and the Cosc terminal of the integrated circuit may be used as the input terminal 136 described above.

  Next, the operation at normal temperature and the operation at low temperature of the electrodeless discharge lamp lighting device of this embodiment will be described with reference to FIG. FIG. 13A shows an operation waveform at a normal temperature, and FIG. 13B shows an operation waveform at a low temperature. FIGS. 13A and 13B show only the envelope of the high-frequency voltage Vcoil between both ends of the induction coil 5.

  What should be noted in the present embodiment is that the time occupancy reduction means comprising the PWM oscillation circuit 13 and the frequency setting circuit 131 when the ambient temperature of the electrodeless discharge lamp 6 is not more than a specified temperature lower than room temperature is PWM. The purpose is to reduce the frequency fpwm of the signal Vpwm. Thereby, the said re-ignition starting time occupation rate falls and the lighting of the electrodeless discharge lamp 6 can be stabilized.

  Further, in the electrodeless discharge lamp lighting device of the present embodiment, the frequency fe (FIG. 2) is set near the resonance frequency of the resonance circuit included in the power conversion circuit 9 not only at the specified temperature but also at room temperature. Can do. In this case, since the operating frequency finv after the electrodeless discharge lamp 6 performs the re-ignition start is near the peak of the resonance curve (see FIG. 2) at the time of lighting, the component constant included in the power conversion circuit 9 Even when the resonance frequency shifts due to variations in the ambient temperature of the power conversion circuit 9 or changes in the ambient temperature of the power conversion circuit 9, the change in the output of the power conversion circuit 9 due to the shift in the resonance frequency is small, and the electrodeless discharge lamp 6 is turned on. It is possible to stabilize and suppress disappearance.

  Here, as described above, by reducing the frequency fpwm of the PWM signal Vpwm below the specified temperature, the non-lighting period Toff becomes longer, and ions generated in the bulb 214 (see FIG. 8) during the lighting period Ton. Is diffused during the non-lighting period Toff, there is a concern that the re-ignition voltage Ving2 rises and the stress applied to the power conversion circuit 9 increases.

  However, even if the re-ignition voltage Ving2 rises, the semiconductor element (for example, MOSFETs that constitute the switching elements Q3 and Q4) included in the power conversion circuit 9 and the capacitor Cp (for example, film) included in the power conversion circuit 9 below the specified temperature. Since the resistance of the capacitor and the like to the current / voltage is increased, there is no problem even if the stress on the power conversion circuit 9 increases.

  Further, in the conventional electrodeless discharge lamp apparatus that operates at an operating frequency of several tens of kHz to several MHz, the core portion around which the induction coil 5 is wound in the coupler 319 is secured in order to ensure the inductance of the induction coil 5. Ferrite cores are often used. In this case, if the dimming frequency at the time of dimming is, for example, between several tens of Hz and several kHz, a high re-ignition voltage Ving2 is generated in the induction coil 5 at the time of re-ignition start, and the transient current flowing in the induction coil 5 Therefore, distortion may occur in the ferrite core, the ferrite core may vibrate, and noise from the coupler 319 may be generated.

  However, as shown in FIG. 14, in the temperature region below the specified temperature, the re-ignition voltage Ving2 tends to decrease as the temperature decreases. Therefore, even if the ambient temperature of the electrodeless discharge lamp 6 is lower than the specified temperature and the oscillation frequency of the PWM oscillation circuit 13 is set lower than that at room temperature, the re-ignition voltage Ving2 does not increase compared to that at room temperature. There is no problem because there is no increase in stress on the power conversion circuit 9 and the generation of the noise described above.

  Further, when the high-frequency power supplied to the non-electric discharge lamp 6 is lowered, or when deep lighting control is performed and the re-ignition start time occupation ratio is increased, the ambient temperature of the electrodeless discharge lamp 6 is not normal. Even if the lighting of the electrode discharge lamp 6 is stable, there is a concern that the lighting becomes unstable below the specified temperature.

  However, in this embodiment, by reducing the frequency fpwm of the PWM signal Vpwm below the specified temperature, the re-ignition start time occupancy can be reduced without increasing the high-frequency power. It is possible to reduce the high-frequency power supplied to the non-powered discharge lamp 6 and to deepen the light control while stabilizing the lighting of the lamp 6.

  Here, when it is desired to reduce the high-frequency power supplied to the electrodeless discharge lamp 6, the time ratio of the lighting period Ton is maintained after lowering the high-frequency power to some extent by lowering the time ratio of the lighting period Ton. Then, the high frequency voltage Vcoil is lowered by shifting the operating frequency finv in the lighting period Ton from the resonance frequency of the resonance circuit included in the power conversion circuit 9 so that the re-ignition start time occupation ratio does not increase any more. A method is also conceivable.

  However, in this case, the operating frequency finv in the lighting period Ton is relatively deviated from the resonance frequency, so that the lighting of the electrodeless discharge lamp 6 becomes unstable and tends to disappear in some cases.

  In this regard, in the present embodiment, the operating frequency finv in the lighting period Ton is set near the resonance frequency of the resonance circuit included in the power conversion circuit 9, thereby stabilizing the lighting of the electrodeless discharge lamp 6 and the electrodeless discharge lamp 6. This is advantageous because the high-frequency power supplied to can be lowered or deep dimming can be performed.

(Embodiment 3)
The basic configuration of the electrodeless discharge lamp lighting device of the present embodiment is substantially the same as that of the first embodiment. As shown in FIG. 15, in the power conversion circuit 9, the switching element Q4 has one end opposite to the switching element Q3. A current detection resistor R51 is connected, and the temperature detection means is configured by the resistor 51, and is different in that the ambient temperature of the electrodeless discharge lamp 6 is detected by detecting the current flowing through the switching element Q4. The description of the same configuration as that of the first embodiment is omitted.

  As shown in FIG. 6 described above, when the ambient temperature of the electrodeless discharge lamp 6 is lower than a specified temperature lower than the normal temperature, the high-frequency power decreases as the temperature decreases. Therefore, by detecting the high frequency power, the ambient temperature of the electrodeless discharge lamp 6 can be detected due to its temperature dependency. Here, it has been found by conventional studies that the high-frequency power can be detected with high accuracy from the drain current value of the switching element Q4 made of a MOSFET included in the power conversion circuit 9. For example, the smaller the drain current value, the higher the high-frequency power. Is low. Then, as shown in FIG. 6, it can be determined that the lower the high frequency power is, the lower the ambient temperature of the electrodeless discharge lamp 6 is, and it is closer to a temperature region where the lighting of the electrodeless discharge lamp 6 becomes unstable.

  In the present embodiment, the ambient temperature of the electrodeless discharge lamp 6 may be detected by providing the high-frequency voltage Vcoil detection unit and detecting the detected high-frequency voltage Vcoil.

  In the present embodiment, the ambient temperature of the electrodeless discharge lamp 6 is read even when the electrodeless discharge lamp 6 is installed at a location away from the power conversion circuit 9 while keeping the temperature detection unit in the power conversion circuit 9. It becomes possible. In particular, by adopting the temperature detection unit shown in the present embodiment as the temperature detection unit in the first embodiment, it is possible to further reduce the temperature dependence of the light output of the electrodeless discharge lamp 6 below the specified temperature. It becomes.

(Embodiment 4)
The basic configuration of the electrodeless discharge lamp lighting device of the present embodiment is substantially the same as that of the first embodiment, and the PWM oscillation circuit 13 changes the time ratio and frequency fpwm of the lighting period Ton based on the output of the temperature detecting means. .

  Next, the operation at normal temperature and the operation at low temperature of the electrodeless discharge lamp lighting device of this embodiment will be described with reference to FIG. FIG. 16A shows an operation waveform at normal temperature, and FIG. 16B shows an operation waveform at low temperature. FIGS. 16A and 16B show only the envelope of the high-frequency voltage Vcoil across the induction coil 5.

  What should be noted in this embodiment is that the time occupancy reduction means such as the PWM oscillation circuit 13 when the ambient temperature of the electrodeless discharge lamp 6 is equal to or lower than the normal temperature lowers the frequency fpwm of the PWM signal Vpwm. At the same time, the time ratio of the lighting period Ton is increased so that the non-lighting period Toff becomes the same as that at room temperature.

  In this embodiment, since the re-ignition start time occupancy can be lowered by increasing the time ratio of the lighting period Ton below the prescribed temperature, the lighting of the electrodeless discharge lamp 6 can be stably performed below the prescribed temperature. It becomes possible to make it. The non-lighting period Toff below the specified temperature is the same as the non-lighting period Toff at room temperature, and the re-ignition voltage Ving2 below the specified temperature is the same as at room temperature. Furthermore, in order to increase the time ratio of the lighting period Ton below the specified temperature, the large decrease in light output of the electrodeless discharge lamp 6 below the specified temperature is moderated, and the light output below the specified temperature depends on the ambient temperature. It can also be reduced.

The electrodeless discharge lamp lighting device in Embodiment 1 is shown, (a) is a circuit diagram, (b) is a circuit diagram of a drive circuit, (c) is a principal part circuit diagram. It is operation | movement explanatory drawing same as the above. It is operation | movement explanatory drawing same as the above. It is operation | movement explanatory drawing same as the above. It is operation | movement explanatory drawing same as the above. It is a characteristic view of the electrodeless discharge lamp used for the same. It is a principal part circuit diagram same as the above. It is a schematic side view in which the electrodeless discharge lamp in the above is partially broken. It is a schematic perspective view of the electrodeless discharge lamp lighting device same as the above. It is a schematic side view of the lighting fixture provided with the electrodeless discharge lamp lighting device same as the above. It is the schematic front view which fractured | ruptured partially the lighting fixture provided with the electrodeless discharge lamp lighting device same as the above. It is a principal part circuit diagram of the electrodeless discharge lamp lighting device in Embodiment 2. It is operation | movement explanatory drawing same as the above. It is a characteristic view of the electrodeless discharge lamp used for the same. It is a circuit diagram of the electrodeless discharge lamp lighting device in the third embodiment. It is operation | movement explanatory drawing same as the above. It is operation | movement explanatory drawing of a prior art example. It is operation | movement explanatory drawing of a prior art example.

Explanation of symbols

1 lighting circuit 5 induction coil 6 electrodeless discharge lamp 9 power conversion circuit 10 diode bridge 11 drive circuit 12 start sweep circuit 13 PWM oscillation circuit 41 on-duty setting circuit 44 ambient temperature detection circuit E DC power supply

Claims (7)

  A power conversion circuit for receiving a power supply from a DC power supply and outputting a high-frequency voltage, the power conversion circuit including at least a switching element and a resonance circuit, connected between an output terminal of the power conversion circuit, and a discharge gas in a bulb An induction coil disposed in the vicinity of the electrodeless discharge lamp enclosing the electrode and an operating period of the power conversion circuit to control the operating frequency of the power conversion circuit and set the high-frequency voltage to a size at which the electrodeless discharge lamp is lit and a size that does not light up A frequency control circuit that causes the electrodeless discharge lamp to blink by alternately switching a non-lighting period to be set, temperature detection means for detecting an ambient temperature of the electrodeless discharge lamp, and a temperature detected by the temperature detection means At the time of re-ignition start, which is the occupancy rate of the time required for re-ignition start of the electrodeless discharge lamp in the lighting period in the blinking operation when the temperature is below a specified temperature lower than normal temperature An electrodeless discharge lamp lighting apparatus characterized by having a time occupancy reduction means for reducing the occupancy.   2. The non-lighting start time occupancy rate according to claim 1, wherein the time occupancy rate lowering unit decreases the re-ignition start time occupancy rate by increasing a time ratio of the lighting period to the non-lighting period in the blinking operation. Electrode discharge lamp lighting device.   A PWM oscillation circuit for supplying a PWM signal to the frequency control circuit, the frequency control circuit performing control of the operating frequency based on a PWM signal from the PWM oscillation circuit; 3. The electrodeless discharge lamp lighting device according to claim 1, wherein the re-ignition start time occupation ratio is reduced by lowering a frequency of the PWM signal. 4.   4. The electrodeless discharge lamp lighting device according to claim 1, wherein the frequency control circuit sets the operating frequency in the lighting period to be close to a resonance frequency of the resonance circuit. 5.   5. The electrodeless discharge lamp lighting device according to claim 1, wherein the temperature detection unit detects the ambient temperature by detecting a current flowing through the switching element. 6.   The electrodeless discharge lamp lighting device according to any one of claims 1 to 4, wherein the temperature detecting means detects the ambient temperature by a temperature sensitive element.   A lighting fixture comprising the electrodeless discharge lamp lighting device according to any one of claims 1 to 6.

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