JP4876463B2 - Discharge lamp lighting device, lighting fixture, and lighting system - Google Patents

Description

  The present invention relates to a discharge lamp lighting device, a lighting fixture, and a lighting system for lighting a high-pressure discharge lamp that needs to be applied with a high voltage during startup, such as a mercury lamp or a metal halide lamp.

  FIG. 9 shows a conventional discharge lamp lighting device using an inverter circuit having a full bridge configuration, and a DC power supply circuit 1 that rectifies and smoothes the AC output of the AC power supply Vs to convert it to a desired DC output, and a DC power supply circuit. An inverter circuit 2 for converting a DC voltage output of 1 into a desired rectangular wave voltage, a high-pressure discharge lamp DL to which the rectangular wave voltage of the inverter circuit 2 is supplied, and an igniter circuit for applying a high-pressure pulse to the high-pressure discharge lamp DL at start-up 10.

  The DC power supply circuit 1 includes a rectifier 1a that full-wave rectifies the AC output of the AC power supply Vs, a boost chopper circuit 1b that boosts the rectified output to a desired DC voltage, and a chopper control circuit that controls the boost operation of the boost chopper circuit 1b. 1c.

  The step-up chopper circuit 1b includes a series circuit of an inductor L1 and a diode D1 inserted on the positive side of the rectified output, a switching element Q1 formed of a MOS FET connected between the rectified outputs via the inductor L1, and an output terminal. The rectified output is boosted to a desired DC output by turning on / off the switching element Q1. The chopper control circuit 1c detects the output voltage of the boost chopper circuit 1b, and performs on / off control of the switching element Q1 so that the detected output voltage becomes a predetermined voltage.

  The inverter circuit 2 includes a step-down chopper circuit 2b that steps down the output of the DC power supply circuit 1 to a desired voltage, a polarity inversion circuit 2c that converts the output of the step-down chopper circuit 2b into a rectangular wave voltage, and an inverter control circuit 2e. Is done.

  The step-down chopper circuit 2b includes a series circuit of a switching element Q10 and an inductor L3 made of a MOS FET inserted in the positive output of the DC power supply circuit 1, and a diode D2 connected between the input terminals via the switching element Q10. And a capacitor C6 connected between the output terminals.

  The polarity inverting circuit 2c is composed of a series circuit of switching elements Q11 and Q12 made of a MOS type FET connected between the output terminals of the step-down chopper circuit 2b, and a series circuit of switching elements Q13 and Q14, and the connection of the switching elements Q11 and Q12. The high pressure discharge lamp DL and the igniter circuit 10 are connected between the midpoint and the midpoint of connection of the switching elements Q13 and Q14.

  The inverter control circuit 2e detects the output voltage of the step-down chopper circuit 2b, performs on / off control of the switching element Q10 so that the detected output voltage becomes a predetermined voltage, and switches the switching elements Q11, Q14 and the switching element Q12. , Q13 are alternately turned on and off (FIGS. 10A to 10D), and the polarity inversion circuit 2c outputs the rectangular wave voltage Vo and applies it to the high-pressure discharge lamp DL (FIG. 10E). ). At this time, the lamp voltage VDL (or lamp current or lamp power) is detected, and the switching control of the switching elements Q11 to Q14 is performed according to the lamp voltage VDL, thereby adjusting the power supplied to the high-pressure discharge lamp DL. .

  The igniter circuit 10 includes a series circuit of a resistor R10 and a capacitor C10 connected between a connection midpoint of the switching elements Q11 and Q12 and a connection midpoint of the switching elements Q13 and Q14, and a Sidac connected in parallel to the capacitor C10. Such a voltage response element S10 and a primary winding N11 of the pulse transformer PT10 and a secondary winding N12 of the pulse transformer PT10 connected in series to the high-pressure discharge lamp DL. A high-pressure pulse is applied to the high-pressure discharge lamp DL via. The series circuit of the high pressure discharge lamp DL and the secondary winding N12 is connected between the connection midpoint of the switching elements Q11 and Q12 and the connection midpoint of the switching elements Q13 and Q14.

  Hereinafter, the operation of the igniter circuit 10 will be described with reference to the waveform diagrams of FIGS. First, when the inverter circuit 2 operates, the capacitor C10 is gradually charged with a predetermined time constant via the resistor R10 by the rectangular wave voltage Vo output from the polarity inversion circuit 2c (FIG. 11A). When the voltage Vc10 across the capacitor C10 rises and reaches the threshold voltage Vbo of the voltage response element S10, the voltage response element S10 is turned on, and the charge of the capacitor C10 is discharged through the voltage response element S10 and the primary winding N11. (FIG. 11B). At this time, the voltage generated in the primary winding N1 is boosted by the secondary winding N12 having a larger number of turns than the primary winding N11, and the high voltage pulse Vp is superimposed on the rectangular wave voltage Vo (FIG. 11 (c)). )). Then, by applying a lamp voltage VDL, in which the high-voltage pulse Vp is superimposed on the rectangular wave voltage Vo output from the inverter circuit 2, between the electrodes of the high-pressure discharge lamp DL, the high-pressure discharge lamp DL breaks down and shifts to a lighting state. .

  FIG. 12 shows an example in which the igniter circuit 20 is used in the discharge lamp lighting device of FIG. 9. The igniter circuit 20 includes a capacitor C20 connected in parallel to the high-pressure discharge lamp DL and an inductor L20 connected in series to the high-pressure discharge lamp DL. The capacitor C20 and the inductor L20 constitute a series resonant circuit.

  At the time of starting, the switching elements Q11 and Q14 and the switching elements Q12 and Q13 are alternately turned on and off (FIGS. 13A to 13D). The switching frequency at this time is the polarity inversion circuit 2c. In order to reduce the size of the capacitor C20 and the inductor L20, the switching element Q11 has a frequency at which the capacitor C20 and the inductor L20 can resonate using the output of The frequency is set to 5 kHz to 200 kHz in consideration of the performance of .about.Q14. The capacitor C20 and the inductor L20 are designed so that a desired resonance pulse can be obtained at a switching frequency of 5 kHz to 200 kHz. Then, the high-pressure discharge lamp DL breaks down by this resonance pulse, and shifts to a lighting state.

  Next, FIG. 14 shows a conventional discharge lamp lighting device using an inverter circuit of a half bridge configuration. A series circuit of switching elements Q21 and Q22 composed of bipolar transistors connected between output terminals of a DC power supply E1, an electrolytic capacitor A series circuit of C21 and C22, diodes D21 and D22 connected in antiparallel to switching elements Q21 and Q22, respectively, and a connection midpoint of switching elements Q21 and Q22 and a connection midpoint of electrolytic capacitors C21 and C22 are connected. This is a half-bridge inverter composed of a series circuit of an inductor L30 and a high-pressure discharge lamp DL and a capacitor C30 connected in parallel to the high-pressure discharge lamp DL. By turning on and off the switching elements Q21 and Q22, the high-pressure discharge lamp A rectangular wave voltage is supplied to DL.

Hereinafter, the lamp starting method will be described. Control signals as shown in FIGS. 15A and 15B are input to the switching elements Q21 and Q22, respectively, and the electrolytic capacitors C21 and C22 are charged with about half the voltage of the DC power source E1, respectively. Then, the operation is performed in the order of the period T1->T2->T3-> T4. First, in the periods T1, T3, the switching elements Q21, Q22 are alternately turned on / off, and the high frequency as shown in FIG. A lamp voltage VDL is applied to the high-pressure discharge lamp DL. In the period T2, the switching element Q22 is turned off and the switching element Q21 is turned on / off at a high frequency, whereby a positive DC voltage Va is applied to the high-pressure discharge lamp DL. In the period T4, the switching element Q21 is turned off and the switching element Q22 is turned on / off at a high frequency, so that the negative DC voltage −Va is applied to the high-pressure discharge lamp DL. Then, by setting the switching frequency of the switching elements Q21 and Q22 during the high-frequency operation period of the periods T1 and T3 to be close to the resonance frequency of the series resonance circuit (no load state) composed of the inductor L30 and the capacitor C30. A high voltage resonance pulse for starting can be generated by the resonance operation of L30 and capacitor C30. (For example, see Patent Document 1)
Japanese Patent No. 2948600

  However, since the igniter circuit shown in FIGS. 12 and 14 is a resonance boost type using a resonance circuit of an inductor and a capacitor, the control circuit is complicated to control the LC resonance. Also, considering the case where extension of the tube lamp circuit length is required, the design of the resonant circuit becomes difficult.

  Further, since the igniter circuit shown in FIG. 9 uses the output of the inverter circuit as a power source and the high voltage pulse output is linked to the operation of the inverter circuit, only one high voltage pulse is provided for each positive / negative polarity of the ramp voltage VDL. Cannot be output, and a smooth transition from glow discharge at start-up to arc discharge is difficult.

  The present invention has been made in view of the above-described reasons, and an object of the present invention is to provide a discharge lamp lighting device, a lighting fixture, and an illumination that enable a smooth transition from glow discharge at start-up to arc discharge with a simple structure. To provide a system.

According to the first aspect of the present invention, there is provided an inverter circuit for converting a DC voltage output from a DC power source into an AC voltage and supplying the same to a discharge lamp, charging means charged by the DC voltage, and charging from the DC power source to the charging means. An igniter comprising at least one switching element provided in a path, and generating a high-voltage pulse to be superimposed on the AC voltage by discharging the charging means after the switching element is turned on and charging the charging means and a circuit, wherein the igniter circuit, the after start of the operation of the inverter circuit, the switching element is turned on during the period when the same polarity alternating voltage of the high voltage pulse is supplied to the discharge lamp, the high pressure the pulse starts operation to superimpose on the AC voltage, since, by superimposing the high-voltage pulse in the bipolar of the AC voltage And features.

According to the present invention, since a high voltage pulse at the time of starting is generated using a DC voltage as a power source, a plurality of high voltage pulses can be continuously superimposed, and a transition from a glow discharge at the time of starting to an arc discharge can be performed with a simple structure. Can be done smoothly. In addition, since the operation of the igniter circuit is started after the inverter circuit has started to operate, the midpoint of the inverter circuit is stable during operation of the igniter circuit, and it is possible to prevent circuit malfunction and detection. . In addition, the operation timing of an igniter circuit that operates using a DC voltage as a power source can be easily controlled by a switching element. Further, the pulse height becomes sufficiently high, and the transition from glow discharge to arc discharge is performed smoothly.

A second aspect of the present invention is that, in the first aspect, the inverter circuit has a half-bridge configuration, and at least two capacitors having different capacities are connected in series to divide the direct current voltage output from the direct current power source into different voltages, The AC voltage is generated by alternately using the divided voltages as the power source, and the inverter circuit has a small capacity during the period in which the AC voltage having the same polarity as the high-voltage pulse is supplied to the discharge lamp. According to the present invention, the output voltage of the DC power supply can be lowered and the component stress can be suppressed, so that the size and cost of the component can be reduced. Is possible.

According to a third aspect of the present invention, in the first or second aspect, the switching element is turned on when the igniter circuit is in operation, and is turned off after the discharge lamp is turned on.

  According to the present invention, the operation timing of an igniter circuit that operates using a DC voltage as a power source can be easily controlled by the switching element.

According to a fourth aspect of the present invention, there is provided a lighting fixture comprising: the discharge lamp lighting device according to any one of the first to third aspects; and a lamp provided with a discharge lamp that is supplied with electric power by the discharge lamp lighting device. .

According to this invention, the lighting fixture which can have the same effect as any one of Claims 1 thru | or 3 can be provided.

The invention of claim 5 is characterized in that the lighting system includes the lighting fixture of claim 4 and performs lighting control.

According to the present invention, it is possible to provide an illumination system that can achieve the same effect as that of the fourth aspect .

As described above, in the present invention, since a high-voltage pulse at the time of starting is generated using a DC voltage as a power source, a plurality of high-voltage pulses can be continuously superimposed, and an arc can be generated from a glow discharge at the time of starting with a simple structure. The transition to discharge can be performed smoothly, and since the operation of the igniter circuit is started after the inverter circuit always starts operating, the midpoint of the inverter circuit is stable during the operation of the igniter circuit. There is an effect that it is possible to prevent circuit malfunction and detection. Further, the pulse height becomes sufficiently high, and the transition from glow discharge to arc discharge is performed smoothly.

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

(Embodiment 1)
As shown in FIG. 1, the discharge lamp lighting device of the present embodiment includes a DC power supply circuit 1 that rectifies and smoothes the AC output of the AC power supply Vs and converts it into a desired DC output, and a DC voltage output of the DC power supply circuit 1. An inverter circuit 2 that converts the voltage into a desired rectangular wave voltage, a load circuit 3 including a high-pressure discharge lamp DL to which the rectangular wave voltage of the inverter circuit 2 is supplied, and an igniter circuit that applies a high-pressure pulse to the high-pressure discharge lamp DL at the time of starting 4.

  The DC power supply circuit 1 includes a rectifier 1a that full-wave rectifies the AC output of the AC power supply Vs, a boost chopper circuit 1b that boosts the rectified output to a desired DC voltage, and a chopper control circuit that controls the boost operation of the boost chopper circuit 1b. 1c.

  The step-up chopper circuit 1b includes a series circuit of an inductor L1 and a diode D1 inserted on the positive side of the rectified output, and a switching element Q1 composed of a MOS FET connected between the rectified outputs via the inductor L1, By turning on / off the switching element Q1, the rectified output is boosted to a desired DC output. The chopper control circuit 1c detects the output voltage of the boost chopper circuit 1b, and performs on / off control of the switching element Q1 so that the detected output voltage becomes a predetermined voltage.

  The inverter circuit 2 includes a series circuit of a high-voltage side electrolytic capacitor C1 and a low-voltage side electrolytic capacitor C2 connected between output terminals of the DC power supply circuit 1, a high-voltage side switching element Q2 made of a MOS type FET, and a low-voltage side switching circuit. It is composed of a series circuit with the element Q3, an inverter control circuit 2a for controlling on / off of the switching elements Q2 and Q3, and a current-limiting inductor L2 having one end connected to the connection midpoint of the switching elements Q2 and Q3. It is a half-bridge inverter, and by connecting the load circuit 3 between the connection midpoint of the electrolytic capacitors C1 and C2 and the other end of the inductor L2, the inverter control circuit 2a turns on and off the switching elements Q2 and Q3. The rectangular voltage is supplied to the load circuit 3 by alternating the DC voltage from the DC power supply circuit 1. Here, the electrolytic capacitors C1 and C2 have the same capacity. If the output voltage of the DC power supply circuit 1 is 600V, the capacitor voltages Vc1 and Vc2 are 300V. The switching elements Q1 to Q3 are illustrated as FETs, but may be bipolar transistors.

  The load circuit 3 includes a high-pressure discharge lamp DL and a capacitor C3 connected between a connection midpoint of the electrolytic capacitors C1 and C2 and the other end of the current-limiting inductor L2. The high pressure discharge lamp DL is lit by the rectangular wave voltage.

  The igniter circuit 4 includes a resistor R1 connected in parallel to a series circuit of electrolytic capacitors C1 and C2, a capacitor C4 and a switching element Q4 such as an FET, and a voltage response element S1 such as a Sidac connected in parallel to the capacitor C4. The high-voltage discharge lamp DL is composed of a series circuit with the primary winding N1 of the pulse transformer PT1 and a secondary winding N2 of the pulse transformer PT1 connected in series with the high-pressure discharge lamp DL. A high pressure pulse is applied to. A series circuit of the high-pressure discharge lamp DL and the secondary winding N2 is connected in parallel to the capacitor C3.

  Hereinafter, the operation of the inverter circuit 2 will be described with reference to the waveform diagrams of FIGS. First, when there is no load when the lamp is not lit, the switching element Q2 is turned on / off at a high frequency (chopping) period Tq2 and the switching element Q3 is turned on / off at a high frequency (chopping) period Tq3 alternately at a low frequency. The rectangular wave voltage Vo is supplied to the high-pressure discharge lamp DL (FIG. 2 (e)).

  Then, after the inverter circuit 2 starts the above operation, the inverter control circuit 2a turns on the switching element Q4 of the igniter circuit 4 during the chopping period Tq2 of the switching element Q2 (FIG. 2 (c)).

  Then, current flows from the output of the DC power supply circuit 1 through the resistor R1, the capacitor C4, and the switching element Q4, and the capacitor C4 is charged. When the voltage Vc4 across the capacitor C4 rises and reaches the threshold voltage Vbo of the voltage response element S1, the voltage response element S1 is turned on and the charge of the capacitor C4 is discharged (FIG. 2 (d)), and the voltage response from the capacitor C4. An oscillating current flows through the element S1 and the primary winding N1.

  The voltage generated in the primary winding N1 is boosted by the secondary winding N2 having more turns than the primary winding N1, and a high voltage pulse Vp of 3 kV to 5 kV is superimposed on the rectangular wave voltage Vo (FIG. 2 ( e)).

  Then, by applying a lamp voltage VDL obtained by superimposing the high-voltage pulse Vp to the rectangular wave voltage Vo output from the inverter circuit 2 between the electrodes of the high-pressure discharge lamp DL, the high-pressure discharge lamp DL breaks down and undergoes an arc through glow discharge. Transition to discharge and steady lighting. Even during stable lighting, the chopping period Tq2 'of the switching element Q2 and the chopping period Tq3' of the switching element Q3 are alternately repeated at a low frequency. However, the frequency at which the chopping periods Tq2 'and Tq3' are switched may be different from the frequency at which the chopping periods Tq2 and Tq3 are switched. Then, when the lighting state is shifted, the switching element Q4 is turned off to stop the operation of the igniter circuit 4.

  Since the igniter circuit 4 of the present embodiment uses the output of the DC power supply circuit 1 as a power source, the generated high-voltage pulse Vp has a positive polarity, and the rectangular wave voltage Vo is superimposed on the chopping period Tq3 in which the negative polarity is applied. The pulse height is lowered, making it difficult to smoothly transition from glow discharge to arc discharge. Therefore, the switching element Q4 is turned on during the chopping period Tq2 in which the polarity of the rectangular wave voltage Vo is positive as described above to start the operation of the igniter circuit 4, and the high voltage pulse Vp generated by the igniter circuit 4 By first superimposing on the rectangular wave voltage Vo, the pulse height becomes sufficiently high, and the transition from glow discharge to arc discharge is performed smoothly.

  Furthermore, since the high-voltage pulse Vp is generated using the output of the DC power supply circuit 1 as a power supply, a plurality of high-voltage pulses Vp can be continuously superimposed for each chopping period Tq2, Tq3 regardless of the operation of the inverter circuit 2. The transition from glow discharge to arc discharge is performed more smoothly.

  In addition, by turning on the switching element Q4 after the inverter circuit 2 has started operating and starting the operation of the igniter circuit 4, the midpoint of the inverter circuit 2 is stable when the igniter circuit 4 is operating, It is possible to prevent circuit malfunction and detection.

  In the present embodiment, since the inverter circuit 2 has a half-bridge configuration, the number of components can be reduced and the cost can be reduced as compared with the full-bridge configuration.

(Embodiment 2)
As shown in FIG. 3, the discharge lamp lighting device of this embodiment is provided with a load circuit 3, an igniter circuit 4, and an inverter control circuit 2d in the conventional discharge lamp lighting device having a full bridge configuration shown in FIG. The configurations of the DC power supply circuit 1, the step-down chopper circuit 2b, and the polarity inversion circuit 2c are the same as those in FIG.

  The igniter circuit 4 includes a series circuit of a resistor R1 connected in parallel to the output terminal of the step-down chopper circuit 2b, a capacitor C4, and a switching element Q4 such as an FET, a voltage response element S1 such as a sidac connected in parallel to the capacitor C4, and a pulse. A series circuit including a primary winding N1 of the transformer PT1 and a secondary winding N2 of the pulse transformer PT1 connected in series to the high-pressure discharge lamp DL. The high-voltage discharge lamp DL is connected via the secondary winding N2. Apply high voltage pulse.

  The series circuit of the high-pressure discharge lamp DL and the secondary winding N2 is connected in parallel to the capacitor C3, and the high-pressure discharge lamp DL and the capacitor C3 constitute the load circuit 3.

  The inverter control circuit 2d detects the output voltage of the step-down chopper circuit 2b, performs on / off control of the switching element Q10 so that the detected output voltage becomes a predetermined voltage, and switches the switching elements Q11 to Q11 of the polarity inversion circuit 2c. Q14, on / off control of the switching element Q4 of the igniter circuit 4 is also performed.

  Hereinafter, the operation of the inverter circuit 2 will be described with reference to the waveform diagrams of FIGS. First, when there is no load when the lamp is not lit, an ON period Tq11 for turning on the switching elements Q11 and Q14 and an ON period Tq12 for turning off the switching elements Q12 and Q13 are alternately switched at a low frequency (FIG. 4). (A) to (d)), the rectangular wave voltage Vo is supplied to the high-pressure discharge lamp DL (FIG. 4G).

  Then, after the inverter circuit 2 starts the above operation, the inverter control circuit 2a turns on the switching element Q4 of the igniter circuit 4 in synchronization with the ON period Tq11 of the switching elements Q11 and Q14 (FIG. 4 (e)).

  Then, current flows from the output of the DC power supply circuit 1 through the resistor R1, the capacitor C4, and the switching element Q4, and the capacitor C4 is charged. When the voltage Vc4 across the capacitor C4 rises and reaches the threshold voltage Vbo of the voltage response element S1, the voltage response element S1 is turned on to discharge the charge of the capacitor C4 (FIG. 4 (f)), and the voltage response from the capacitor C4. An oscillating current flows through the element S1 and the primary winding N1.

  The voltage generated in the primary winding N1 is boosted by the secondary winding N2 having more turns than the primary winding N1, and a high voltage pulse Vp of 3 kV to 5 kV is superimposed on the rectangular wave voltage Vo (FIG. 4 ( g)).

  Then, by applying a lamp voltage VDL obtained by superimposing the high-voltage pulse Vp to the rectangular wave voltage Vo output from the inverter circuit 2 between the electrodes of the high-pressure discharge lamp DL, the high-pressure discharge lamp DL breaks down and undergoes an arc through glow discharge. Transition to discharge and steady lighting. Even during stable lighting, the ON period Tq11 'of the switching elements Q11 and Q14 and the ON period Tq12' of the switching elements Q12 and Q13 are alternately repeated at a low frequency. However, the frequency at which the on periods Tq11 'and Tq12' are switched may be a frequency different from the frequency at which the on periods Tq11 and Tq12 are switched. Then, when the lighting state is shifted, the switching element Q4 is turned off to stop the operation of the igniter circuit 4.

  Since the igniter circuit 4 of the present embodiment uses the output of the DC power supply circuit 1 as a power supply, the high voltage pulse Vp to be generated is positive, and even if it is superimposed on the on period Tq12 in which the rectangular wave voltage Vo is negative, The pulse height is lowered, making it difficult to smoothly transition from glow discharge to arc discharge. Therefore, as described above, the switching element Q4 is turned on only during the on period Tq11 in which the polarity of the rectangular wave voltage Vo is positive, the igniter circuit 4 is operated, and the high voltage pulse Vp generated by the igniter circuit 4 is converted into a positive rectangular shape. By superimposing only on the wave voltage Vo, the pulse height becomes sufficiently high, and the transition from glow discharge to arc discharge is performed smoothly.

  Furthermore, since the high-voltage pulse Vp is generated using the output of the DC power supply circuit 1 as a power supply, a plurality of high-voltage pulses Vp can be continuously superimposed every on-period Tq11 regardless of the operation of the inverter circuit 2, and glow discharge The transition from arc to arc discharge is smoother.

  In addition, by turning on the switching element Q4 after the inverter circuit 2 has started operating and starting the operation of the igniter circuit 4, the midpoint of the inverter circuit 2 is stable when the igniter circuit 4 is operating, It is possible to prevent circuit malfunction and detection.

(Embodiment 3)
The discharge lamp lighting device of the present embodiment is one in which the capacities of the electrolytic capacitors C1, C2 of the first embodiment are different from each other, and other configurations are the same as those of the first embodiment, and the description thereof is omitted.

  Here, conditions necessary for lighting the high-pressure discharge lamp DL are shown below. In order to smoothly shift the high pressure discharge lamp DL from the glow discharge to the arc discharge, a no-load voltage of 250 to 300 V or more is required after dielectric breakdown between the lamp electrodes occurs due to the high pressure pulse of the igniter circuit 4. In order to achieve this voltage condition in the first embodiment, a voltage of 250V must be applied to the electrolytic capacitors C1 and C2, and the DC power supply circuit 1 must supply a DC voltage of 500V.

When the AC power is converted into DC by the DC power supply circuit 1, it is necessary to boost the output voltage to a DC voltage of input voltage × √2 × 1.1 in order to reduce input current distortion. (Here, 1.1 represents 10% power supply fluctuation tolerance.)
Further, after the high pressure discharge lamp DL is lit, the inverter circuit 2 alternately applies the voltages Vc1 and Vc2 of the electrolytic capacitors C1 and C2 to the high pressure discharge lamp DL, so that the capacitor voltages Vc1 and Vc2 are the lamp stable lighting voltage ( Generally 70 to 120 V) or more was necessary.

  The high pressure discharge lamp lighting circuit of the present embodiment is designed as follows to satisfy the above conditions. First, the voltage required to smoothly shift the high-pressure discharge lamp DL from glow discharge to arc discharge may be supplied only when one of the switching elements Q2 and Q3 is chopped, and the capacitor voltage Vc1. , Vc2 may be set to be equal to or higher than the voltage required for dielectric breakdown. For example, if Vc1 = 300V so that one capacitor voltage Vc1 is equal to or higher than the voltage necessary for dielectric breakdown, Vc2 = 150V is set so that the other capacitor voltage Vc2 is equal to or higher than the lamp stable lighting voltage.

  From the above, the DC power supply circuit 1 may output a DC voltage of 450V. In order to output a 450V DC voltage while reducing the input current distortion in the DC power supply circuit 1, the voltage of the AC power supply Vs may be 290V or less from 450V ÷ √2 ÷ 1.1 = 290V. It can correspond to power supplies 100V and 242V, and commercial power supplies 120V and 277V in the United States.

  Therefore, in order to set the capacitor voltage Vc1 = 300V and the capacitor voltage Vc2 = 150V as described above, if the capacitance of the electrolytic capacitor C1: the capacitance of the electrolytic capacitor C2 is set to 1: 2, the DC power supply circuit 1 The output voltage can be lowered as compared with the first embodiment. Therefore, component stress is suppressed, and the inverter circuit 2 can be designed with components satisfying a withstand voltage of 450 V, and the components can be reduced in size and cost.

  Also in this embodiment, as shown in FIGS. 5A to 5E, the switching element Q4 is turned on in the chopping period Tq2 in which the polarity of the rectangular wave voltage Vo is positive, and the operation of the igniter circuit 4 is started. Then, the high voltage pulse Vp generated by the igniter circuit 4 is first superimposed on the 300 V positive rectangular wave voltage Vo, so that the pulse height becomes sufficiently high, and the transition from glow discharge to arc discharge is performed smoothly. .

  Furthermore, since the high-voltage pulse Vp is generated using the output of the DC power supply circuit 1 as a power supply, a plurality of high-voltage pulses Vp can be continuously superimposed for each chopping period Tq2, Tq3 regardless of the operation of the inverter circuit 2. The transition from glow discharge to arc discharge is performed more smoothly.

  In addition, by turning on the switching element Q4 after the inverter circuit 2 has started operating and starting the operation of the igniter circuit 4, the midpoint of the inverter circuit 2 is stable when the igniter circuit 4 is operating, It is possible to prevent circuit malfunction and detection.

  As in the second embodiment, the switching element Q4 is turned on only during the on period Tq2 in which the polarity of the rectangular wave voltage Vo is positive, the igniter circuit 4 is operated, and the high voltage pulse Vp generated by the igniter circuit 4 is positive. Alternatively, it may be superimposed only on the rectangular wave voltage Vo.

(Embodiment 4)
FIGS. 6 to 8 are illuminations in which the high pressure discharge lamp lighting device according to any one of the first to third embodiments is housed in the housing 10 and the high pressure discharge lamp DL mounted in a socket (not shown) in the lamp 11 is turned on. Shows the appearance of the instrument. Since these lighting fixtures use the high-pressure discharge lamp lighting device according to any one of Embodiments 1 to 3, the transition from glow discharge to arc discharge can be performed smoothly, and further, malfunction and detection of a circuit can be prevented. It can be done.

  6 and 8 are track light compatible instruments using a high pressure discharge lamp DL such as an HID lamp as a spotlight, and FIG. 7 is an instrument using a high pressure discharge lamp DL such as an HID lamp as a downlight.

  Furthermore, if the lighting system which performs lighting control of each lighting fixture using these lighting fixtures is constructed | assembled, the effect similar to the above can be acquired also as a system.

It is a figure which shows the structure of the discharge lamp lighting device of Embodiment 1 of this invention. (A)-(e) It is a figure which shows the operation | movement at the time of a start same as the above. It is a figure which shows the structure of the discharge lamp lighting device of Embodiment 2 of this invention. (A)-(g) It is a figure which shows the operation | movement at the time of a start same as the above. (A)-(e) It is a figure which shows the operation | movement at the time of start of Embodiment 3 of this invention. It is a figure which shows the external appearance structure of the 1st illuminating device of Embodiment 4 of this invention. It is a figure which shows the external appearance structure of the 2nd illuminating device same as the above. It is a figure which shows the external appearance structure of a 3rd illuminating device same as the above. It is a figure which shows the structure of the conventional 1st discharge lamp lighting device. (A)-(e) It is a figure which shows operation | movement of the inverter circuit same as the above. (A)-(c) It is a figure which shows the operation | movement at the time of a start same as the above. It is a figure which shows the structure of the 2nd conventional discharge lamp lighting device. (A)-(d) It is a figure which shows the operation | movement at the time of a start same as the above. It is a figure which shows the structure of the conventional 3rd discharge lamp lighting device. (A)-(c) It is a figure which shows the operation | movement at the time of a start same as the above.

DESCRIPTION OF SYMBOLS 1 DC power supply circuit 2 Inverter circuit 3 Load circuit 4 Igniter circuit R1 Resistor C4 Capacitor Q4 Switching element S1 Voltage response element PT Pulse transformer N1 Primary winding N2 Secondary winding DL High pressure discharge lamp

Claims (5)

An inverter circuit for converting a DC voltage output from a DC power source into an AC voltage and supplying the same to a discharge lamp;
Charging means charged by the DC voltage, comprising at least one switching element provided in a charging path from the DC power supply to the charging means, and after the switching element is turned on to charge the charging means, An igniter circuit that generates a high-voltage pulse to be superimposed on the AC voltage by discharging the charging means;
The igniter circuit after the start of operation of said inverter circuit, said switching element is turned on during a period when the same polarity alternating voltage of the high voltage pulse is supplied to the discharge lamp, the alternating voltage the high voltage pulse The discharge lamp lighting device is characterized in that an operation for superimposing the voltage on the AC voltage is started, and thereafter, the high-voltage pulse is superimposed on both polarities of the AC voltage . The inverter circuit has a half-bridge configuration, and at least two capacitors having different capacities are connected in series to divide the DC voltage output from the DC power source into different voltages, and each divided voltage is alternately used as the power source. The period in which the AC voltage is generated and the AC voltage having the same polarity as the high-voltage pulse is supplied to the discharge lamp is when the inverter circuit is operated with a capacitor having a small capacity as a power source. The discharge lamp lighting device according to claim 1. The discharge lamp lighting device according to claim 1 or 2, wherein the switching element is turned on when the igniter circuit is in operation and turned off after the discharge lamp is lit. A lighting fixture comprising: the discharge lamp lighting device according to any one of claims 1 to 3; and a lamp having a discharge lamp supplied with electric power by the discharge lamp lighting device. A lighting system comprising the lighting fixture of claim 4 and performing lighting control.

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