JP2012243706A - Discharge lamp lighting device and lighting fixture using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device capable of supplying both positive and negative polarities with adequate power even when a half-wave discharge occurs, and a lighting fixture using the same.SOLUTION: A discharge lamp lighting device includes: a step-down chopper circuit 4 for power-converting DC power to AC power to supply a high-voltage discharge lamp DL with the converted power; a load voltage detection section 61 for detecting positive and negative load voltages +V and -V applied to the high-voltage discharge lamp; a comparator section 62 for comparing the positive and negative load voltages +V and -V detected by the load voltage detection section 61 to determine whether or not the high-voltage discharge lamp DL is in a half-wave discharging state; and a control circuit 6 for controlling power to be supplied to the high-voltage discharge lamp DL from the step-down chopper circuit 4. After the comparator section 62 determines that it is in the half-wave discharging state, the control circuit 6 controls the step-down chopper circuit 4 to output a positive load current in accordance with the positive load voltage +V in the previous cycle and a negative load current in accordance with the negative load voltage -V in the previous cycle.

Description

  The present invention relates to a discharge lamp lighting device and a lighting fixture using the same.

  Conventionally, there is a discharge lamp lighting device that lights a discharge lamp by applying an AC voltage generated by a resonance action of a resonance circuit to the discharge lamp. A conventional discharge lamp lighting device reads and reads either a positive load voltage or a negative load voltage applied to the discharge lamp so that desired electric power is supplied to the discharge lamp. Set the target value of the load current according to the load voltage. Then, desired electric power is supplied to the discharge lamp by controlling so that the positive and negative load currents coincide with the target value.

  However, when the positive load voltage and the negative load voltage applied to the discharge lamp are significantly different (half-end discharge state), the target value of the load current required to supply the desired power is positive and negative. Different by sex. For this reason, the desired power is supplied with the polarity at which the load voltage is read, but the load current value required for supplying the desired power is different from the target value at the polarity different from the read polarity. Power is not supplied.

  For example, if a half-wave discharge occurs in which the positive load voltage is lower than the negative load voltage, and the target value of the load current is set by reading the positive load voltage, the target value will be It becomes larger than the appropriate value of the current. As a result, the negative output power (negative load voltage × load current (target value)) exceeds the desired power, which may cause a failure of the discharge lamp lighting device or a shortened life of the discharge lamp.

  Therefore, there is a discharge lamp lighting device that compares positive and negative load voltages applied to a discharge lamp and sets a target value of positive and negative load currents from a load voltage with a higher load voltage (for example, Patent Document 1). When a half-wave discharge occurs, this discharge lamp lighting device compares positive and negative load voltages, and sets a target value of load current from a load voltage having a higher load voltage. As a result, when a half-wave discharge occurs, the output power does not exceed the desired power even in a polarity different from the read polarity, thus preventing the failure of the discharge lamp lighting device and the shortening of the discharge lamp life. Can do.

JP 2010-257659 A

  However, when a half-wave discharge occurs, the discharge lamp lighting device of Patent Document 1 sets the target value of the load current from the polarity with the higher load voltage, and the positive and negative polarity load currents match the target value. To control. Therefore, it becomes impossible to supply an appropriate load current to the polarity with the lower load voltage. In other words, when the load current having the lower polarity of the load voltage becomes smaller than the appropriate value, the dimming state occurs and problems such as lamp extinction occur.

  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 capable of supplying appropriate power to both positive and negative polarities even when half-wave discharge occurs, and to use the same. It is to provide the lighting equipment that was.

  The discharge lamp lighting device of the present invention detects a power supply circuit that converts DC power into AC power and supplies the power to the discharge lamp, and a positive load voltage and a negative load voltage applied to the discharge lamp. A load voltage detection unit, a comparison unit that compares the positive load voltage and the negative load voltage detected by the load voltage detection unit to determine whether or not a half-wave discharge state; and A control circuit for controlling the power supplied from the power supply circuit to the discharge lamp, and the control circuit determines that the comparison unit is in a half-wave discharge state, and then the positive load voltage in the previous cycle. The power supply circuit is controlled so that a positive load current corresponding to the negative load current and a negative load current corresponding to the negative load voltage in the previous cycle are output.

  In this discharge lamp lighting device, the control circuit determines that the comparison unit is not in a half-wave discharge state, and then selects one of the positive load voltage and the negative load voltage in the previous cycle. It is preferable to control the power supply circuit so that a positive load current and a negative load current corresponding to the voltage are output.

  In this discharge lamp lighting device, the comparison unit is in a half-wave discharge state when a difference between the positive load voltage and the negative load voltage detected by the load voltage detection unit is a predetermined value or more. It is preferable to judge that.

  In this discharge lamp lighting device, the control circuit determines that the comparison unit is in a half-wave discharge state, and then has a polarity of one of the positive load voltage and the negative load voltage that has a higher load voltage. It is preferable to shorten the period during which the load voltage is output.

  In the lighting fixture of the present invention, a power supply circuit for converting DC power into AC power and supplying the discharge lamp, and a load voltage for detecting a positive load voltage and a negative load voltage applied to the discharge lamp A detection unit, a comparison unit that compares the positive load voltage detected by the load voltage detection unit and the negative load voltage and determines whether or not a half-wave discharge state is present; and the power supply A control circuit for controlling the power supplied from the circuit to the discharge lamp, and the control circuit determines that the comparison unit is in a half-wave discharge state and then responds to a positive load voltage in a previous cycle. A discharge lamp lighting device that controls the power supply circuit so that a positive load current and a negative load current corresponding to a negative load voltage in a previous cycle are output; and the discharge lamp lighting device Lit by And electric light, characterized in that it comprises said discharge lamp lighting device with an instrument body wherein the discharge lamp is provided.

  As described above, the present invention has an effect that appropriate power can be supplied to both positive and negative polarities even when half-wave discharge occurs.

It is a circuit block diagram of the discharge lamp lighting device of Embodiment 1 of this invention. (A) It is a timing chart of load voltage. (B) It is a timing chart of load current. (C) It is a timing chart of output electric power. It is a graph which shows a VI characteristic table. (A) It is a timing chart of load voltage. (B) It is a timing chart of load current. (C) It is a timing chart of output electric power. It is an external view of the lighting fixture 2 of Embodiment 2. FIG. It is an external view of the lighting fixture 2 of Embodiment 2. FIG. It is an external view of the lighting fixture 2 of Embodiment 2. FIG.

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

(Embodiment 1)
The circuit block diagram of the high pressure discharge lamp lighting device 1 of this embodiment is shown in FIG. The high pressure discharge lamp lighting device 1 (discharge lamp lighting device) of the present embodiment includes a full-wave rectifier circuit 2, a step-up chopper circuit 3, a polarity inversion step-down chopper circuit 4 (power supply circuit), and a starting voltage generation circuit 5 And a control circuit 6.

  The full-wave rectifier circuit 2 is a diode bridge circuit that is connected to the commercial AC power supply Vs, generates a pulsating voltage obtained by rectifying the AC voltage output from the commercial AC power supply Vs, and outputs the pulsating voltage to the boost chopper circuit 3. The step-up chopper circuit 3 receives the pulsating voltage generated by the full-wave rectifier circuit 2, generates a DC voltage Vdc obtained by stepping up the voltage, and outputs the DC voltage Vdc to the polarity inversion step-down chopper circuit 4. The polarity inversion step-down chopper circuit 4 (hereinafter abbreviated as step-down chopper circuit 4) is controlled so as to step down the DC voltage Vdc and supply appropriate power to the high-pressure discharge lamp DL (discharge lamp). A rectangular wave AC voltage is applied to DL. Further, when the high pressure discharge lamp DL is started, a high frequency voltage for driving the resonance type starting voltage generating circuit 5 is generated.

  Next, the configuration of the step-up chopper circuit 3, the step-down chopper circuit 4, the starting voltage generation circuit 5, and the control circuit 6 will be described.

  The step-up chopper circuit 3 includes an input capacitor C1, an inductor L1, a switching element Q1, a diode D1, a smoothing capacitor C2, and a control unit 31.

  An input capacitor C1 is connected between the output terminals of the full-wave rectifier circuit 2, and a series circuit of an inductor L1 and a switching element Q1 is connected in parallel with the input capacitor C1. A series circuit composed of a diode D1 and a smoothing capacitor C2 is connected in parallel with the switching element Q1. The control unit 31 performs switching control of the switching element Q1.

  With the above configuration, the switching element Q1 is switching-controlled at a frequency sufficiently higher than the commercial frequency of the commercial AC power supply Vs, so that the pulsating voltage output from the full-wave rectifier circuit 2 is boosted to a predetermined DC voltage Vdc. And the smoothing capacitor C2 is charged. In addition, the control unit 31 performs power factor improvement control for imparting resistance to the circuit so that the phase of the input current and the input voltage from the commercial AC power supply Vs is not shifted. A filter circuit for preventing high-frequency leakage may be provided at the AC input end of the full-wave rectifier circuit 2.

  The step-down chopper circuit 4 is composed of a full bridge circuit having switching elements Q2 to Q5 made of MOSFETs. Between the output terminals of the step-up chopper circuit 3, a series circuit composed of switching elements Q2 and Q3 and a series circuit composed of switching elements Q4 and Q5 are connected in parallel. A series circuit including an inductor L2 serving as an output filter and a capacitor C3 is connected between a connection point between the switching elements Q2 and Q3 and a connection point between the switching elements Q4 and Q5.

  The starting voltage generation circuit 5 is constituted by a resonance circuit including a pulse transformer PT and a capacitor C4, and uses a DC voltage Vdc applied to the step-down chopper circuit 4 as a power source. The starting voltage generating circuit 5 generates a resonant boosted voltage for starting / restarting applied to the high-pressure discharge lamp DL by switching the switching elements Q2 to Q5 of the step-down chopper circuit 4 at a high frequency. .

  The control circuit 6 includes a load voltage detection unit 61, a comparison unit 62, a storage unit 63, and a switching control unit 64, and performs switching control of the switching elements Q2 to Q5. The load voltage detector 61 detects a positive and negative load voltage applied to the high-pressure discharge lamp DL. The comparison unit 62 compares the positive and negative load voltages detected by the load voltage detection unit 61 and determines whether or not it is in a half-wave discharge state. The storage unit 63 stores a VI characteristic table (see FIG. 3) indicating a load current corresponding to the load voltage. As shown in FIG. 3, the VI characteristic table shows the relationship between the load voltage and the load current for supplying appropriate power, and is configured such that the load current decreases as the load voltage increases. ing. The switching control unit 64 determines whether the high-pressure discharge lamp DL is lit or not based on the load voltage detected by the load voltage detection unit 61, and performs switching control of the switching elements Q2 to Q5. The operation mode is switched between the start mode and the lighting mode.

  In the first operation period in which the start mode is performed, a high voltage for starting the high pressure discharge lamp DL is generated. In the second operation period in which the lighting mode is performed, the load current corresponding to the load voltage of the high-pressure discharge lamp DL detected by the load voltage detection unit 61 with reference to the VI characteristic table stored in the storage unit 63 is referred to. Is supplied to the high-pressure discharge lamp DL, the operating frequency and on-period of the switching elements Q4 and Q5 are controlled.

  Next, operation | movement of the high pressure discharge lamp lighting device 1 of this embodiment is demonstrated.

  When the commercial AC power supply Vs is turned on, the control unit 31 turns on / off the switching element Q1 at about several tens of kHz and appropriately controls the pulse width according to the DC voltage Vdc. Thus, the DC voltage Vdc is controlled to be a predetermined value when the high pressure discharge lamp DL is not lit and when the high pressure discharge lamp DL is lit. The step-up chopper circuit 3 has a function of increasing the input power factor from the commercial AC power source Vs and suppressing input current distortion.

  When the DC voltage Vdc reaches a predetermined value, the step-down chopper circuit 4 starts operating. At this time, the high-pressure discharge lamp DL is in a non-lighting state where it is not lit, the high-pressure discharge lamp DL is the same as the open state, and the equivalent impedance is a high impedance state close to infinity. At this time, the step-down chopper circuit 4 starts the operation in the start mode for starting the high pressure discharge lamp DL. In the start mode, the switching elements Q2 and Q5 are turned on and the switching elements Q3 and Q4 are turned on alternately at a predetermined frequency f0 (several hundreds of kHz). This frequency f0 is a frequency close to the resonance frequency fr of the resonance frequency of the series resonance circuit composed of the primary winding n1 of the pulse transformer PT and the capacitor C4, and a sinusoidal high voltage is generated in the primary winding n1. The sinusoidal high voltage generated in the primary winding n1 is boosted (high voltage for starting) by the turn ratio between the primary winding n1 and the secondary winding n2 of the pulse transformer PT, and is increased through the capacitor C3. Applied to the discharge lamp DL. As a result, the dielectric breakdown occurs between both ends of the high-pressure discharge lamp DL, and the high-pressure discharge lamp DL is started.

  When the high pressure discharge lamp DL is started by the high voltage for starting generated during the start mode, the high pressure discharge lamp DL is in a low impedance state close to a short circuit, and the load voltage of the high pressure discharge lamp DL is reduced to approximately 0V. When the load voltage of the high-pressure discharge lamp DL detected by the load voltage detection circuit 21 falls below a predetermined lighting determination voltage threshold, the switching control unit 24 determines that the high-pressure discharge lamp DL has been lit. Then, the operation of the step-down chopper circuit 4 is switched to a lighting mode for stabilizing the lighting state of the high-pressure discharge lamp DL.

  In the lighting mode, the switching elements Q2 and Q3 are alternately turned on and off at a predetermined low frequency fa (about several hundred Hz). At that time, the switching element Q2 is turned on / off at a predetermined high frequency fb (about several tens of kHz) during the on period of the switching element Q2, and the switching element Q4 is turned on at a predetermined high frequency fb. -Repeat the operation to turn off. By this polarity inversion step-down chopper operation, a rectangular wave AC voltage having a frequency fa is applied to the high-pressure discharge lamp DL. At this time, the capacitor C3 and the inductor L2 function as a filter circuit of the step-down chopper circuit 4, and the antiparallel diodes built in the switching elements Q4 and Q5 function as a regenerative current energizing diode of the step-down chopper circuit 4.

  The high-pressure discharge lamp DL has a low lamp voltage immediately after start-up, and the voltage across the lamp rises to reach the rated value as the inside of the arc tube becomes hot and high in pressure, and is in a stable lighting state. Then, the control circuit 6 detects the load voltage of the high-pressure discharge lamp DL every cycle, and refers to the VI characteristic table stored in the storage unit 63 from the detected load voltage to load current for the next cycle. Determine the target value. Then, the load current is matched with the target value by controlling the chopping frequency and the ON period of the switching elements Q4 and Q5. By repeating this control every cycle, appropriate power is supplied to the high pressure discharge lamp DL, and the high pressure discharge lamp DL can be stably lit.

  Next, specific control of the control circuit 6 will be described with reference to FIGS. 2A is a timing chart showing the load voltage, FIG. 2B is a timing chart showing the load current, and FIG. 2C is a timing chart showing the output power.

  The period in which the positive polarity load voltage is output is defined as the positive polarity on period + Ton, the period in which the negative polarity load voltage is output is defined as the negative polarity on period -Ton, and the positive polarity on period + Ton and the negative polarity The sex on-period -Ton has the same length. Then, the absolute value of the positive and negative load voltages is 90V, and one cycle in which half-wave discharge is not generated is defined as a cycle T1, and the cycle T1 is determined from the positive on-period + Ton1 and the negative on-period -Ton1. Become. In addition, the next cycle after the cycle T1 is defined as a cycle T2, and the cycle T2 includes a positive ON period + Ton2 and a negative ON period -Ton2, and a half-wave discharge occurs and the negative load voltage is 90V. It fluctuates to 150V. In addition, one period following the period T2 is defined as a period T3, and the period T3 includes a positive on-period + Ton3 and a negative on-period -Ton3, and the half-wave discharge state continues. The positive polarity on periods + Ton1, + Ton2, and + Ton3 have the same length, and the negative polarity on periods -Ton1, -Ton2, and -Ton3 have the same length.

  First, the load voltage detection unit 61 detects a positive and negative load voltage of the high-pressure discharge lamp DL, and outputs the detection result to the comparison unit 62. The comparison unit 62 holds the detection result of the positive load voltage and the negative load voltage for one cycle. Then, the comparison unit 62 determines whether or not it is in a half-wave discharge state by comparing the absolute value of the held positive polarity load voltage with the absolute value of the negative polarity. Hereinafter, the absolute value of the positive load voltage is referred to as load voltage + V, and the absolute value of the negative load voltage is referred to as load voltage −V. The comparison unit 62 determines that the high-pressure discharge lamp DL is in a half-wave discharge state when the positive and negative polarity load voltage difference (difference between + V and −V) is a predetermined value or more (for example, a load voltage difference of 20 V or more). To do.

  Since the cycle T1 is a positive load voltage + V = 90 V and a negative load voltage −V = 90 V, the comparison unit 62 determines that it is not in a half-wave discharge state. In this case, the switching control unit 64 refers to the storage unit 63 and acquires the target value (1.67 A) of the load current according to the positive load voltage + V (= 90 V). In the cycle T2, the switching control unit 64 performs control so that each of the positive load current and the negative load current becomes the acquired target value (1.67 A). In this embodiment, when it is determined that the half-wave discharge state is not set, a target value of the load current corresponding to the positive load voltage + V is set, but the load corresponding to the negative load voltage −V is set. A target value of current may be set.

  In the cycle T2, the comparison unit 62 compares the load voltage + V = 90V in the positive polarity on-period + Ton2 with the load voltage -V = 150V in the negative polarity on-period -Ton2, and the load voltage difference is 60V. Judged to be in a half-wave discharge state.

  When the comparison control unit 62 determines that the comparison unit 62 is in the half-wave discharge state, the switching control unit 64 stores the target value of the load current corresponding to each of the positive and negative load voltages + V and −V in the storage unit 63. Obtained based on the VI characteristic table (see FIG. 3). In this case, since the positive load voltage + V = 90 V in the positive ON period + Ton2, the target value of the positive load current is 1.67A. Further, since the negative load voltage −V −− = 150 V in the negative ON period −Ton2, the target value of the negative load current is 1.0A.

  Then, the switching control unit 64 performs control so that the positive load current matches the target value (1.67 A) and the negative load current matches the target value (1.0 A) in the period T3. In the period T3, the half-wave discharge state continues, and the load voltage + V = 90V in the positive ON period + Ton3 and the load voltage −V = 150V in the negative ON period −Ton3. Therefore, the positive output power in the period T3 is 150 W (= 90 V × 1.67 A), the negative output power is 150 W (= 150 V × 1.0 A), and even in the half-wave discharge state, the positive and negative The power appropriate for the sex will be supplied.

  Further, since the half-wave discharge state continues in the period T3, the comparison unit 62 compares the positive and negative load voltages + V and −V in the period T3 and determines that the half-wave discharge state is present. Then, the switching control unit 64 sets a positive load current target value and a negative load current target value in accordance with the positive and negative load voltages + V and −V in the cycle T3, and in the next cycle, the positive and negative values. Control is performed so that each of the bipolar load currents matches the target value.

  That is, in the present embodiment, the positive and negative polarity load voltages + V and −V are compared every cycle to determine whether or not the half-wave discharge state is present. Then, after determining that the state is a half-wave discharge state, the positive load current according to the positive load voltage + V in the previous cycle and the negative load voltage −V according to the negative load voltage −V in the previous cycle. The control circuit 6 controls the step-down chopper circuit 4 so that the load current is output. As a result, even during half-wave discharge, positive and negative bipolar load currents corresponding to both positive and negative load voltages + V and -V are output. Will be supplied.

  As described above, in this embodiment, even when half-wave discharge occurs, appropriate power is supplied to both positive and negative polarities. Therefore, the lamp life is deteriorated due to overpower, the circuit stress is increased, and the dimming state is caused. It is possible to prevent the high pressure discharge lamp DL from going off or the like.

  Further, when the comparison unit 62 determines that a half-wave discharge state is detected from the positive and negative load voltages + V and −V detected by the load voltage detection unit 61, the following control may be performed in addition to the above control. Good.

  As shown in FIGS. 4A to 4C, the comparison unit 62 includes a positive load voltage + V (= 90 V) detected by the load voltage detection unit 61 in the period T2 and a negative load voltage −V. (= 150 V) and a half-wave discharge state is determined.

  Then, the switching control unit 64 performs control so that the ON period of the polarity (negative polarity) having the higher load voltage is shortened. That is, the switching control unit 64 controls the step-down chopper circuit 4 so that the negative ON period is −Ton2a (<−Ton2). Also, since the half-wave discharge state continues in the period T3, the same control as described above is performed, and the switching control unit 64 controls the negative ON period to be −Ton3a (<−Ton3). .

  The load current in the cycle T2 where the half-wave discharge has occurred is determined based on the load voltage in the immediately preceding cycle T1. Therefore, the negative load current in the cycle T2 is set according to the positive load voltage + V = 90 V in the cycle T1, and is 1.67A. Accordingly, overpower is supplied in the negative ON period -Ton2 in the cycle T2. In order to prevent this, it is necessary to know in advance that half-wave discharge occurs, but this is technically difficult.

  Therefore, in the present embodiment, when the above control is performed and it is determined that the state is a half-wave discharge state, the ON period of the polarity with the higher load voltage is shortened. As a result, the time during which the overpower is supplied immediately after the half-wave discharge is generated is shortened, so that the lamp life and the component stress can be reduced.

  In the above description, when the comparison unit 62 determines that the half-wave discharge state is present, control is performed so that the ON period of the polarity with the higher load voltage is shortened. In some cases, control may be performed so that the ON period of this polarity is shortened.

(Embodiment 2)
The external view of the lighting fixture 11 of this embodiment is shown in FIGS. The lighting fixture 11 of the present embodiment houses the high-pressure discharge lamp lighting device 1 of the first embodiment, the high-pressure discharge lamp DL that is lit by the high-pressure discharge lamp lighting device 1, and the high-pressure discharge lamp lighting device 1, and the high-pressure discharge lamp It is comprised with the instrument main body 7 to which the electric lamp DL is attached. The appliance main body 7 includes a housing 8 that houses the high-pressure discharge lamp lighting device 1 and the ballast, and a lamp 9 in which a high-pressure discharge lamp DL is mounted in a socket (not shown). The housing 8 and the lamp 9 are connected by a wiring 10, the high pressure discharge lamp lighting device 1 and the high pressure discharge lamp DL are electrically connected, and the high pressure discharge lamp DL is lit.

  5 and 6 show a lighting fixture 11 corresponding to a track light using a high pressure discharge lamp DL as a spotlight, and FIG. 7 shows a lighting fixture 11 using a high pressure discharge lamp DL as a downlight.

  Since the lighting fixture 11 includes the high-pressure discharge lamp lighting device 1 according to the first embodiment, even when a half-wave discharge occurs in the high-pressure discharge lamp DL, appropriate power is supplied to both positive and negative polarities. . Therefore, the luminaire 11 can prevent deterioration of the lamp life due to overpower, increase of circuit stress, extinction of the high-pressure discharge lamp DL due to dimming state, etc. even if half-wave discharge occurs.

  Further, a lighting system may be constructed by combining a plurality of lighting fixtures 11.

1 High pressure discharge lamp lighting device (discharge lamp lighting device)
2 Full-wave rectifier circuit 3 Boost chopper circuit 4 Polarity inversion step-down chopper circuit (power supply circuit)
5 Start Voltage Generating Circuit 6 Control Circuit 61 Load Voltage Detection Unit 62 Comparison Unit 63 Storage Unit 64 Switching Control Unit DL High Pressure Discharge Lamp (Discharge Lamp)

Claims (5)

A power supply circuit that converts DC power into AC power and supplies it to a discharge lamp;
A load voltage detector for detecting a positive load voltage and a negative load voltage applied to the discharge lamp;
A comparison unit that compares the positive load voltage detected by the load voltage detection unit with the negative load voltage and determines whether or not a half-wave discharge state;
A control circuit for controlling the power supplied from the power supply circuit to the discharge lamp,
After determining that the comparison unit is in a half-wave discharge state, the control circuit responds to a positive load current according to a positive load voltage in a previous cycle and a negative load voltage in a previous cycle. The discharge lamp lighting device controls the power supply circuit so that a negative load current is output.   The control circuit determines that the comparison unit is not in a half-wave discharge state, and then determines the positive polarity according to any one of the positive load voltage and the negative load voltage in the previous cycle. The discharge lamp lighting device according to claim 1, wherein the power supply circuit is controlled so that a load current and a negative load current are output.   The comparison unit determines that it is in a half-wave discharge state when a difference between the positive load voltage detected by the load voltage detection unit and the negative load voltage is equal to or greater than a predetermined value. The high pressure discharge lamp lighting device according to claim 1 or 2, characterized in that:   After the control circuit determines that the comparison unit is in a half-wave discharge state, a period in which a load voltage having one of the positive polarity and the negative polarity is output. The discharge lamp lighting device according to claim 1, wherein the discharge lamp lighting device is shortened. The discharge lamp lighting device according to any one of claims 1 to 4,
A discharge lamp lit by the discharge lamp lighting device;
An illumination fixture comprising: a discharge lamp lighting device; and a fixture main body provided with the discharge lamp.

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