JP4207702B2 - Discharge lamp lighting device - Google Patents

Description

  The present invention relates to a discharge lamp lighting device having an inverter circuit and a resonance circuit.

  FIG. 2 is a circuit diagram showing an example of a conventional discharge lamp lighting device. The discharge lamp lighting device DLA is connected to a commercial power supply SV and includes a DC power supply circuit CV that converts the voltage into a DC smoothed voltage. An inverter circuit IV is connected to the output side of the DC power supply circuit CV. The inverter circuit IV outputs high-frequency power when the switching elements Q1 and Q2 are alternately turned on / off by the inverter control circuit IVCC. An inverter load circuit IL is connected to the output side of the inverter circuit IV. The inverter load circuit IL is composed of a series circuit including a resonance inductor T1, a DC blocking capacitor C2, one filament ft1 of the discharge lamp load LA, a resonance capacitor C1, and the other filament ft2 of the discharge lamp load LA. Has been. In this case, the capacitances of both capacitors C1 and C2 are set such that C1 <C2.

  FIG. 3 is a circuit diagram showing another example of a conventional discharge lamp lighting device. The basic circuit configuration is the same as in FIG. 2, but in the circuit of FIG. 3, the current flowing through the switching element Q2 of the inverter circuit IV is detected by the resistor R1, and the operating frequency of the inverter circuit IV is determined according to the current. A feedback control circuit FBC to be changed is added.

  By the way, conventionally, various standard products have been provided for the discharge lamp LA due to the variety of usage objects. For example, discharge lamps (lamps) of 4 feet length include FHF32 (dedicated Hf lamp: 32W, 45W dual rated lamp), FLR40S (rapid general lamp: 40W), FLR40S / 36 (rapid power saving lamp) : 36W), FL40S (Glow-type general lamp: 40W), FL40SS / 37 (Glow-type power-saving lamp: 37W), etc., there are several types of discharge lamps. There is a difference in the load impedance during lighting due to the difference in the composition of the filled gas.

  Up to now, the same shape and the same filament structure as in a rapid type lamp, and the electrical characteristics of a general lamp (FLR40S: lamp current = 380 mA, lamp voltage = 105 V, lamp power = 40 W) and power-saving lamp (FLR40S) / 36: A lamp current of 400 mA, a lamp voltage of 90 V, a lamp power of 36 W, and a difference of about 10% may be shared by one type of discharge lamp lighting device (ESX4021HK-5ENH manufactured by Matsushita Electric Works) etc).

  However, for example, if all the above five types of discharge lamps are shared by a single type of discharge lamp lighting device, as described above, each discharge lamp has a different load impedance. Therefore, steady lighting in an optimum design state for each load is performed. However, depending on the lamp, there is no choice but to operate in a state where the circuit efficiency is very poor. Means for eliminating the difference in output power have also been proposed, but the circuit efficiency was further deteriorated.

Here, the problem in the prior art will be specifically described with respect to the difference in output power depending on the lamp type and the circuit efficiency.
(1) Difference in output power depending on the type of lamp FIG. 6 is a diagram of the inverter load circuit IL in the conventional discharge lamp lighting device DLA of FIG. 2 from when the AC power supply SV is turned on until the discharge lamp load LA is stably lit. It is a characteristic view showing a resonance curve. Here, the horizontal axis represents the frequency f, the vertical axis represents the voltage VL applied to the discharge lamp LA when there is no load, the output power WL of the discharge lamp LA during lighting, and the filaments ft1 and ft2 of the discharge lamp LA in each mode. A preheating current If for preheating is shown. In addition, as a state after lighting, resonance curves of output power WL of two types of discharge lamps LA (here, an FHF32 lamp and an FLR40S / 36 lamp as an example) are shown.

  When the commercial power supply SV is turned on, the inverter circuit IV first operates in the preheating mode by the inverter control circuit IVCC. In this preheating mode, it operates at the frequency fa for a predetermined time. At this time, a voltage corresponding to the point a on the resonance curve at no load determined by the inductor T1 and the capacitor C1 is applied to both ends of the discharge lamp LA, and at the same time, a constant current corresponding to the point a2 is passed through the capacitor C1. Ifa flows, the filaments ft1 and ft2 of the discharge lamp LA are preheated by this current.

  Next, in order to start and light the discharge lamp LA, the inverter control circuit IVCC causes the inverter circuit IV to shift to the start mode. In this starting mode, the inverter circuit IV operates at the frequency fb, and the voltage VLb corresponding to the point b of the resonance curve is applied to both ends of the discharge lamp LA. When the discharge lamp LA is started, the discharge resistance component of the discharge lamp LA is added to the LC resonance system. For example, when attention is paid to the FHF32 lamp, the resonance curve changes and the point b 'is shifted. In order to obtain a desired lighting output, the inverter circuit IV finally shifts to the lighting mode by the inverter control circuit IVCC. In this lighting mode, the inverter circuit IV operates at the frequency fc.

  Here, when the FHF32 lamp and the FLR40S / 36 lamp are respectively lit, a difference ΔWL is generated in the lamp power at the frequency fc of the lighting mode. This is because the discharge impedances of the individual discharge lamps LA are different, and the resonance curves after the resistance of the discharge lamp LA is included in the LC resonance system are different. In other words, since the discharge impedance of the FLR40S / 36 lamp is smaller than that of the FHF32 lamp, the peak of the resonance curve when the FLR40S / 36 is turned on moves away from the resonance frequency f0 when no load is applied, and the resonance peak itself is also reduced. It tends to go down. In other words, the resonance is weakened.

  As described above, in the conventional discharge lamp lighting device DLA of FIG. 2, the output power difference ΔWL at the time of lighting of a plurality of different types of discharge lamps LA is large, that is, it becomes brighter or darker depending on the type of the discharge lamp LA. There was a problem that it would end up.

  On the other hand, with respect to the discharge lamp lighting device DLA shown in FIG. 3 in which measures for eliminating the lighting output power difference between different lamps are taken, the discharge lamp load LA is stably lit after the AC power supply SV is turned on. A characteristic diagram showing a resonance curve of the inverter load circuit IL is shown in FIG. The horizontal axis, the vertical axis, each resonance curve, and the flow from power-on to the preheating / starting and lighting mode are the same as in FIG.

  In order to obtain a desired lighting output, the inverter circuit IV finally shifts to a lighting mode by the inverter control circuit IVCC. In this lighting mode, the inverter circuit IV uses the current of the switching element Q2 to output power of the discharge lamp LA. The operating frequency is changed to fcα and fcβ by the two types of discharge lamps LA. For this reason, a difference Δfc0 in operating frequency exists.

(2) Circuit Efficiency (2) -1 Reactive Current FIG. 10 shows the switching current of the circuit current IT1 of the inverter load circuit IL and the switching element Q2 of the inverter circuit IV during the substantially in-phase operation and the slow phase operation. Here, the in-phase operation refers to operation at an operation frequency near the resonance frequency f0, and the slow-phase operation refers to operation at a frequency higher than f0. The circuit current IT1 of the inverter load circuit IL is considered to be divided into an effective current and a reactive current depending on the phase shift, and the effective current is used as the output of the discharge lamp LA, and the reactive current is literally involved in the output. It can be said that this is an invalid current. And making the active current components substantially equal leads to making the outputs of the discharge lamps LA substantially equal.

  Inverter load circuit in the case of the slow phase operation with a large reactive current in the state where the effective currents in the substantially in-phase operation and in the slow phase operation are made equal, that is, in the state where the output of the discharge lamp LA is substantially equal, compared with the in-phase operation. As a result, the current IT1 and the current IdQ2 of the switching element Q2 increase, which in turn degrades the circuit efficiency.

  When this is applied to the conventional discharge lamp lighting device DLA, in the discharge lamp lighting device DLA of FIG. 2, as can be seen from FIG. 6, the FLR40S / 36 lamp has an operating frequency relatively far from the resonance frequency f0α. As can be seen from FIG. 7, in the discharge lamp lighting device DLA of No. 3, since the FHF 32 lamp has an operating frequency relatively far from the resonance frequency f0β, each has a load with poor circuit efficiency. FIG. 11 shows circuit waveforms IT1 of the inverter load circuit IL and switching waveforms of the switching element Q2 of the inverter circuit IV in the discharge lamp lighting device DLA of FIG.

(2) -2 Filament preheating current If
The reason why the filaments ft1 and ft2 are preheated before the discharge lamp LA is lit is to reduce the stress on the filaments ft1 and ft2 and facilitate the lighting of the discharge lamp LA. That is, by starting the filaments ft1 and ft2 to an appropriate temperature, thermoelectrons are emitted from the thermoelectron emitting materials (emitters) applied to the filaments ft1 and ft2, and thereby the starting voltage required for lighting the discharge lamp LA. Can be reduced.

  Here, when the filaments ft1 and ft2 are under-heated, the amount of emitted thermoelectrons is small, and the starting voltage required for lighting the discharge lamp LA becomes high. Therefore, damage (sputtering phenomenon) to the filaments ft1 and ft2 due to gas ions in the tube occurs. On the contrary, when the filaments ft1 and ft2 are overheated, the evaporation of thermionic emission material is abnormally accelerated, resulting in an early emitter shortage. Since these cause deterioration of the life of the discharge lamp, the filament preheating requires that an appropriate filament current Ifa is applied for an appropriate time to obtain an appropriate filament temperature.

  In addition, it is necessary to keep the lamp voltage VL applied to both ends of the discharge lamp LA as low as possible so that only the filaments ft1 and ft2 are heated without causing the discharge lamp LA to discharge during pre-heating. This is because the discharge of the filaments ft1 and ft2 during the preceding preheating means discharging in a preheating insufficient state, which causes the above-described sputtering phenomenon.

  Also, the filament preheating current Ifc at the time of stable lighting needs to keep the temperature of the filaments ft1 and ft2 appropriately as before the lighting, and if the temperature of the filaments ft1 and ft2 is lower than the appropriate temperature, a sputtering phenomenon occurs. On the other hand, if the temperature is higher than the appropriate temperature, an early shortage of emitters or the like is caused, which becomes a factor of deteriorating the life of the discharge lamp LA.

However, in the conventional configuration as shown in FIGS. 2 and 3, since the current flowing through the capacitor C1 is the filament current If, the preheating current If and the lamp voltage V1 are in a proportional relationship.
First, in the preheating mode, since the impedance Xc (= 1 / ωC = 1 / (2πfC)) of the capacitor C1 for obtaining an appropriate preheating current If at a low lamp voltage V1 is almost determined, the operating frequency fa in the preheating mode is determined. The capacity of the capacitor C1 is almost determined.

  At this time, since the preheating current at the time of lighting is similarly determined by If = 2πf × C × VL, in the conventional discharge lamp lighting device DLA shown in FIG. 3, the operating frequency fcβ at the time of lighting of the FHF32 lamp is FLR40S / 36. Since it is higher than the operating frequency fcα when the lamp is lit, the filament preheating current Ifcβ tends to increase when the FHF32 lamp is lit. When the operating frequency difference Δfc0 is large, the preheating current difference ΔIfc0 increases accordingly.

  Here, the excessive filament current Ifc during lighting deteriorates the life of the discharge lamp LA due to early shortage of emitters as described above, and increases the loss in the filament, leading to deterioration in circuit efficiency. there were.

On the contrary, when the filament preheating current Ifcβ when the FHF32 lamp is turned on is suppressed to an appropriate value, the preheating mode and the filament preheating current (Ifa and Ifcα) when the FLR40S / 36 lamp is turned on are relatively This leads to a shortage of preheating, leading to a deterioration in the life of the discharge lamp LA due to the sputtering phenomenon.
For this reason, it has been very difficult to achieve the filament preheating condition that satisfies both the circuit efficiency and the lamp life with the conventional technology.

(2) -3 Switching Loss FIG. 12 is an enlarged view of the switching waveform of the switching element Q2 of the inverter circuit IV. The horizontal axis represents time t, and the vertical axis represents the voltage Vs across the switching element Q2, the flowing current Id, and the loss WQ2 of the switching element Q2.

The operating state of the switching element Q2 is repeated as four cycles of (a) off region, (b) turn-on region, (c) on-region, and (d) turn-off region. Here, there is almost no loss of the switching element Q2 in the (a) off region and (b) the turn-on region, and (c) in the on region, the switching element Q2 has an on-resistance R (on), so that Wa = It has a loss of Id ² R (on), and (d) in the turn-off region, the loss of the switching element Q2 appears as Wb.

  Here, (b) turn-on region and (d) turn-off region are substantially constant even if the operating frequency changes due to the delay time of switching element Q2 and the drive delay time of inverter control circuit IVCC. That is, when the circuit current IT1 of the inverter circuit IL is constant and the operating frequency changes, there is no increase in loss in the (a) off region and (c) on region, but (b) the turn on region ( d) As the frequency increases in the turn-off region, the region increases, and the loss of the switching element Q2 relatively increases.

  If this is applied to the conventional discharge lamp lighting device DLA, in the discharge lamp lighting device DLA of FIG. 3, the difference in operating frequency Δfc between the FLR40S / 36 lamp and the FHF32 lamp in the lighting mode is greatly separated. Along with this, the switching loss at the time of FHF32 lamp load tended to increase.

As described above, when all types of discharge lamps having different shapes and ratings are shared by one type of discharge lamp lighting device, it is pointed out in (1) and (2) -1 to 3 above. In addition, because there is a difference in output power between the discharge lamps, and depending on the lamp, the circuit efficiency is very poor. Therefore, in the prior art, a dedicated discharge lamp lighting device for each discharge lamp having a different shape and rating. Is currently used. Therefore, various discharge lamp lighting devices must be prepared according to the type of the discharge lamp LA, resulting in an increase in cost.
JP 2003-168589 A

  The present invention has been made in view of the above-mentioned problems. The object of the present invention is to first eliminate the output power difference during lighting, and secondly, in all the plurality of different types of discharge lamps. The third is to increase the service life by not deteriorating the circuit efficiency, the third is the proper preheating condition, and the fourth is the high reliability of the discharge lamp by sharing a plurality of different types of discharge lamps. It is to provide a lighting device.

In the present invention, in order to solve the above problem, as shown in FIG. 14 , a DC power supply, an inverter circuit connected to the DC power supply, a double resonant circuit connected to the inverter circuit, A discharge lamp powered by a double resonance circuit, a detection circuit that detects a resonance current or a resonance voltage of the double resonance circuit, and a control circuit that varies the operating frequency of the inverter according to the detection value of the detection circuit In the discharge lamp lighting device, the double resonance circuit includes a parallel connection of a first resonance circuit constituted by a series connection of a first inductor and a first capacitor to the inverter. A series connection circuit of a second capacitor and the discharge lamp is connected in parallel, and includes a second resonance circuit including a first inductor, a second capacitor, and a discharge lamp, A preheating circuit for preheating a second inductor is connected to the inverter in parallel with a third resonance circuit, which is a series connection of a second inductor and a third capacitor, separately from the double resonance circuit. A detection circuit configured to supply a preheating current from a winding and detecting the resonance current is configured to detect a current obtained by excluding a current flowing through the preheating circuit from a current flowing through a switching element included in the inverter circuit, The discharge lamp lighting device uses a plurality of discharge lamps with different rated powers as the applicable load, and is characterized in that the operation frequency when each discharge lamp is lit is controlled to be a predetermined value or less .

  According to the present invention, it is possible to light a plurality of discharge lamps having different rated powers with one discharge lamp lighting device, and it is possible to minimize a decrease in efficiency due to a difference in discharge lamp load. A corresponding and highly efficient discharge lamp lighting device can be realized.

(Prerequisite configuration 1)
FIG. 1 is a circuit diagram of Configuration 1 which is a premise of the present invention. The discharge lamp lighting device DLA includes a DC power supply circuit CV that converts a commercial AC power supply SV into a predetermined DC smoothed voltage, and an inverter circuit IV is connected to an output side of the DC power supply circuit CV. An inverter load circuit IL is connected to the output side. Further, a control circuit CVCC that controls on / off driving of the switching element Q3 of the DC power supply circuit CV at high frequency, a control circuit IVCC that controls on / off driving of the switching elements Q1 and Q2 of the inverter circuit IV at high frequency, and inverter control thereof. A control circuit CC including a feedback circuit FBC that detects the resonance current of the inverter load circuit IL and feeds back to the control of the inverter control circuit IVCC is connected to the circuit IVCC. Further, the circuit ground Gnd of the discharge lamp lighting device D1A is connected to the earth ground E / G via the capacitor C17.
Next, the configuration and operation of each constituent circuit block of the discharge lamp lighting circuit DLA will be briefly described.

1) DC power circuit CV
The DC power supply circuit CV is connected to both ends of the commercial power supply SV in parallel with an input of a filter circuit FI that removes high-frequency components generated by an inverter and the like and a surge voltage absorbing element ZNR that absorbs a surge voltage input from the commercial power supply SV. Is connected via a current fuse Fuse that immediately cuts off the circuit from the AC power supply SV when the power supply is short-circuited due to a failure in the discharge lamp lighting device DLA, etc., and the AC voltage is full-wave rectified at the output end of the filter circuit FI. The input of the rectifier DB to be connected is connected, and the inrush current suppression circuit ICC and the series circuit of the input terminals of the boost chopper circuit UVC are connected to the output of the rectifier DB. Furthermore, the switching element Q3 of the step-up chopper circuit UVC is connected to a control circuit CVCC that controls on / off driving of the switching element Q3 at a high frequency.

Here, the configuration and operation of the boost chopper circuit UVC and its control circuit CVCC will be briefly described.
The step-up chopper circuit UVC inputs the voltage via the inrush current suppression circuit ICC to the + output of the rectifier DB, and the primary winding n1 of the inductor T2 and the capacitor C8 are connected to the other end of the primary winding n1 of the inductor T2. Is connected to the drain terminal of the switching element Q3 and the anode of the diode D1, the source terminal of the switching element Q3 is connected to the current detection resistor R2 of the switching element Q3, and the cathode of the diode D1 is connected to the smoothing capacitor C5. The capacitor C8, the current detection resistor R2, the other end of the capacitor C5, and the negative terminal of the rectifier DB are connected to the circuit ground Gnd so as to output a predetermined smoothing voltage Vdc to the capacitor C5.

  The control circuit CVCC is controlled by using a general-purpose chopper control IC, for example, MC33262 manufactured by Motorola, in the PFC which is a control unit IC in the control circuit CVCC, and its configuration is already well known. A detailed description is omitted here, and the configuration of the external parts for the PFC of the control unit IC will be briefly described below.

  A voltage obtained by dividing the smoothed output voltage Vdc by the series circuit of the resistor R14 and the variable resistor VR1 connected in parallel to the smoothing capacitor C5 is input to the first pin (output voltage feedback terminal) of the control circuit IC. A resistor R10 and a capacitor C11 are connected in parallel to the second pin (error amplifier output / compensation terminal). The voltage obtained by dividing the pulsating voltage of the chopper input voltage (the voltage across the capacitor C8) by the resistors R7 and R8 is input to the third pin (multiplier input terminal) after being smoothed by the capacitor C10. In order to detect the current flowing through the switching element Q3, the voltage obtained by the resistor R2 is input to the fourth pin (current sense input terminal) by the capacitor C12 through the resistor R13. The output of the secondary winding n2 of the inductor T2 is input to the fifth pin (zero current detection input terminal) via the resistor R9 in order to detect the zero crossing point of the current flowing through the inductor T2. The 6th pin (ground terminal) is connected to the circuit ground Gnd. The seventh pin (output terminal) is connected to the gate terminal of the switching element Q3 via a resistor R12 in order to drive the switching element Q3. For the power supply of the control circuit CC, the voltage Vcc divided by the resistors R3 and R4 is input to the eighth pin (power supply voltage terminal) after being smoothed by the capacitor C9 and the Zener diode ZD1.

  With the configuration described above, the control circuit PFC detects the input voltage (pulsating voltage) of the boost chopper circuit UVC based on the input of the third pin, and the smoothed output voltage from the boost chopper circuit is detected by the first pin. Drive control of the switching element Q3 while detecting based on the input, detecting the current flowing through the switching element Q3 based on the input of the 4th pin, and further detecting the current flowing through the inductor T2 based on the input of the 5th pin Can be performed.

Next, the configuration and operation of the inrush current suppression circuit ICC will be briefly described.
The inrush current suppression circuit ICC includes a PTC thermistor PTH and a thyristor Q4 connected in parallel. Between the gate and the cathode of the thyristor Q4, a series circuit of the secondary winding n3 of the inductor T2, a resistor R6 and a diode D2, and a resistor R5 And a capacitor C7 are connected in parallel.

  As for the operation of the inrush current suppression circuit ICC, since a voltage is generated in the secondary winding n3 of the inductor T2 during the operation of the boost chopper circuit UVC, the thyristor Q4 is turned on and current is supplied to the boost chopper circuit UVC through the thyristor Q4. When the boost chopper circuit UVC is not operating, almost no voltage is generated in the secondary winding n3 of the inductor T2, so that the thyristor Q4 is turned off and current is supplied to the boost chopper circuit UVC through the PTC thermistor PTH.

  In other words, since the boost chopper circuit UVC does not operate when the power is turned on, the inrush current is suppressed by the PTC thermistor PTH. In normal operation, the boost chopper circuit UVC operates, and the PTC thermistor PTH is short-circuited by the thyristor Q4. The circuit operation is such that no loss due to the thermistor PTH occurs.

2) Inverter circuit IV
The inverter circuit IV receives the output terminal of the DC power supply circuit CV (smoothed output voltage Vdc of the capacitor C5), and the output terminal of the DC power supply circuit CV is connected to the drain terminal of the switching element Q1. The drain terminal of the switching element Q2 is connected to the source terminal, the detection resistor R1 of the feedback circuit FBC is connected to the source terminal of the switching element Q2, and the resistance R1 is connected to the circuit ground GND. The gate terminals of the switching elements Q1 and Q2 and the output terminal Vs of the inverter circuit IV are connected to the control circuit IVCC.

The control circuit IVCC includes an inverter drive circuit IVDR, a timer circuit TIM, and their peripheral components.
Hereinafter, the configuration and operation of peripheral components of the inverter drive circuit IVDR and the timer circuit TIM will be described.
Connected to the first pin (resistor connection terminal for oscillator) of the inverter drive circuit IVDR is a variable resistor VR2, a series circuit of a switch SW2 and a resistor R23, and a parallel circuit of a series circuit of a switch SW1 and a resistor R24. . The capacitor C15 is connected to the 2nd pin (oscillator capacitor connection terminal), the 3rd pin (ground terminal) is connected to the circuit ground Gnd, and the 4th pin (power supply voltage terminal) is used for the power supply of the control circuit. The voltage Vcc divided by the resistors R3 and R4 is input after being smoothed by the capacitor C9 and the Zener diode ZD1. The inverter output voltage Vs is connected to the 5th pin (high voltage side drive reference voltage terminal). A capacitor C14 is connected to the 6th pin (high-voltage side drive power supply terminal) between the 5th pin, the cathode of the diode D5 is connected to the 6th pin, and the same anode is connected to the control power supply Vcc. The 7th pin (high voltage side drive voltage output terminal) is connected to the gate terminal of the switching element Q1 via the resistor R16, and the 8th pin (low voltage side drive voltage output terminal) is connected to the switching element Q2 via the resistor R18. The

  The operation of the inverter drive circuit IVDR is performed at a frequency determined by the resistance value and the capacitance value connected to the 1st and 2nd pins when Vcc reaches the operation start voltage of the 8th pin after the power is turned on. By alternately generating a drive voltage at the eighth pin, the two switching elements Q1, Q2 are alternately turned on / off.

  The resistor R25 is connected to the first pin (oscillator resistance connection terminal) of the timer circuit TIM, the capacitor C15 is connected to the second pin (oscillator capacitor connection terminal), and the third pin (ground terminal) is a circuit. The voltage Vcc divided by the resistors R3 and R4 is smoothed by the capacitor C9 and the Zener diode ZD1 and input to the fourth pin (power supply voltage terminal) for power supply of the control circuit CC. . Switches SW1, 2 and 3 are connected to the 5th, 6th and 7th pins, respectively.

  The timer circuit TIM starts operating with a time constant determined by the resistance value and capacitance value connected to the 1st and 2nd pins when Vcc reaches the operation start voltage of the 8th pin after the power is turned on. Controls the ON / OFF switching time of SW1 to SW3. Specifically, it changes in the sequence shown in FIG.

  First, when the inverter is started, the switch SW1 is turned on, the switch SW2 is turned on, and the switch SW3 is turned off, and the current IVR2 from the first pin of IVDR that is a constant voltage source to the variable resistor VR2, the resistor R23, and the resistor R24. , IR23 and IR24 flow, and the combined current flowing through the first pin: I1 = IVR2 + IR23 + IR24 is transmitted through the inverter drive circuit IVDR to the second pin to which the capacitor C15 is connected at a predetermined magnification n × I1, and the capacitor C15 Charging current IC15charge and discharging current IC15discharge are determined, and the charging / discharging cycle of the capacitor C15, that is, the preheating mode operating frequency fa of the inverter is determined.

  Next, when the preheating mode is finished, the switch SW1 is turned off, the switch SW2 is turned on, and the switch SW3 is turned off, and the current IR24 flowing through the resistor R24 is cut off. The combined current IVR2 + IR23 of the variable resistor VR2 and the resistor R23 flows through the first pin and is transmitted to the capacitor C15 in the same manner as described above, so that the inverter frequency changes to the start mode frequency fb.

  When the start mode ends, the switch SW1 is turned off, the switch SW2 is turned off, and the switch SW3 is turned on, and the current I23 that was flowing through the resistor R23 is cut off. The current IVR2 to the variable resistor VR2 and the combined current IVR2 + IFBC of the current IFBC to the feedback control circuit FBC composed of the switch SW3, the resistor R22, the diode D6, the operational amplifier OP1, and the like flow through the first pin. The frequency of the inverter changes to the lighting mode frequency fc (when there is no current to the feedback control circuit FBC side) and fc ′ (when there is a current to the feedback control circuit FBC side).

  The inverter circuit IV is driven while changing the frequency step by step from the preheating mode (frequency fa), the start mode (frequency fb), the lighting mode (frequency fc), and the feedback control start (frequency fc ′) by the above timer control. Can do.

  Next, the configuration and operation of the feedback control circuit FBC will be described. The feedback control operational amplifier OP1 operates using the control power supply Vcc as a power supply. The reference voltage obtained by dividing the control power supply Vcc by the voltage dividing ratio of the resistor R19 and the variable resistor VR3 is input to the + side input terminal of the operational amplifier OP1, and the current of the switching element Q2 of the inverter circuit IV is input to the − side input terminal. The voltage of the resistor R1 to be detected is input via the resistor R20. A resistor R21 and a capacitor C13 are connected in parallel between the output terminal of the operational amplifier OP1 and the negative input terminal, and a diode D6, a resistor R22 and a switch SW3 are connected between the first pin of the inverter drive circuit IVDR. ing.

  In the operation of the feedback control circuit FBC, the resonance current of the inverter load circuit IL is converted into a voltage by a resistor R1 that detects a current flowing through the switching element Q2 of the inverter circuit IV. Is input. The voltage appearing at the negative terminal of the operational amplifier OP1 is compared with the reference voltage applied to the positive terminal voltage of the operational amplifier OP1, and the output voltage of the operational amplifier OP1 is changed so that both voltages are substantially equal to each other. A change in potential difference between the first pin of the circuit IVDR and the output of the operational amplifier OP1 changes the current IFBC flowing through the switch SW3, the resistor R22, and the diode D6, and has a function of changing the operating frequency of the inverter circuit IV.

  Here, the voltage appearing at the negative terminal of the operational amplifier OP1 changes almost in direct proportion to the power consumption of the inverter load circuit IL. And most of the power consumption of the inverter load circuit IL is occupied by the output power of the discharge lamp load LA. That is, the feedback control circuit FBC varies the operating frequency of the inverter circuit IV, that is, performs constant power control so that the output power of the discharge lamp load LA is substantially constant.

  As described above, as shown in FIG. 8, the feedback control circuit FBC does not operate in the preheating and starting mode by the switch SW3 of the timer circuit TIM, and in the lighting mode, depending on the type of the discharge lamp load LA. The operation frequency of the inverter circuit IV is varied so that the output power of the discharge lamp load LA is substantially constant between fcα and fcβ.

3) Inverter load circuit IL
The inverter load circuit IL is connected between Vs and Gnd, which is the output of the inverter circuit IV, and includes a double resonance circuit DRC that supplies power to the discharge lamp load circuit LA, and a preheating circuit PHC that preheats the discharge lamp filaments ft1 and ft2. Composed. In the double resonance circuit DRC, a primary winding n1 of a resonance inductor L1 and a resonance capacitor C1 are connected in series between Vs and GND, which is an output of the inverter circuit IV, and a discharge lamp load is connected to both ends of the capacitor C1. LA and a resonance / DC blocking capacitor C2 are connected in series. The preheating circuit PHC is configured by connecting the secondary windings n2 and n3 of the resonance inductor T3 to the discharge lamp filaments ft1 and ft2 via capacitors C3 and C4, respectively.

  The detailed operation of this inverter is described below. The circuit operation of the inverter circuit IV and the inverter load circuit IL will be described using the resonance curve shown in FIG. FIG. 4 shows resonance curves of two types of discharge lamp loads LA at the time of lighting (here, an FHF 32 lamp and an FLR 40S / 36 lamp) as in the conventional case (FIG. 6).

  The inverter control circuit IVCC operates the inverter circuit IV at the preheating mode (operating at the frequency fa), the starting mode (operating at the frequency fb), and the lighting mode (feedback) from when the commercial power supply SV is applied to when it is lit. The operation of the control circuit FBC is performed between the frequency fcα and the frequency fcβ) and is switched in a stepwise manner as in the conventional case.

  Here, paying attention to the double resonance circuit DRC, the double resonance circuit DRC is roughly divided into two resonance curves. That is, when there is no load (impedance of discharge lamp LA is ∞) and when the load is short-circuited (impedance of discharge lamp LA is 0).

  When no load is applied, the discharge lamp LA is not attached and is in an open state, so that the capacitor C2 does not contribute to the resonance operation. Therefore, a resonance curve at the resonance frequency f0 determined by the inductor L1 and the capacitor C1 is obtained. On the other hand, since both capacitors C2 and C1 are connected in parallel when the load is short-circuited, a resonance curve is obtained at the resonance frequency f0 'determined by the inductor L1 and both capacitors C2 and C1. Of course, f0> f0 ', and the difference between the resonance frequencies f0 and f0' is determined by the capacitance of the capacitor C2.

  When the discharge lamp LA is lit, a discharge impedance is generated. Since the impedance value is in the range of 0 to ∞, the natural vibration frequency f1 (output peak) of the resonance (output) curve at the time of lighting is always f0 to f0 ′. Exists between.

  Next, paying attention to the preheating circuit of the discharge lamp filaments ft1 and ft2, the secondary windings n2 and n3 of the inductor L1 are used as the power source of the preheating circuit, and the voltage generated in the secondary windings n2 and n3 of the inductor L1 is Since it is proportional to the voltage generated in the primary winding n1 of the inductor L1, the preheating current curve at the time of no load changes substantially along the resonance curve of the double resonance circuit DRC. At the time of lighting, the impedance change due to the frequency change of the capacitors C3 and C4 of the preheating circuit is larger than the voltage change of the inductor L1, and when the frequency decreases, the preheating current decreases due to the increase in impedance of the capacitors C3 and C4. Therefore, the curve is a downward-sloping curve as shown in FIG. This preheating current curve can change the slope of the frequency characteristic by the turns ratio of the inductor L1 and the constants of the capacitors C3 and C4.

Based on the above points, the characteristics at the time of lighting output of the discharge lamp LA and the filament preheating current characteristics in the discharge lamp lighting device DLA according to the presupposed configuration 1 will be described.
1) Lighting characteristics As in the conventional case, when two types of discharge lamps LA (FHF32 lamp and FLR40S / 36 lamp) are turned on, a difference Δfc1 occurs in the operating frequency during lighting as shown in FIG. . This occurs because each discharge lamp LA has a different discharge impedance depending on the type of the discharge lamp LA, and the peak frequency of the resonance curve of the FLR40S / 36 lamp, that is, the natural vibration frequency f0α is unique to the case of the FHF32 lamp. Compared with the vibration frequency f0β, the resonance frequency f0 at no load is moved away from the resonance frequency f0β.

However, as described above, the natural vibration frequency when the discharge lamp LA is in the lighting state always exists between f0 and f0 ′. Therefore, the output peak value of the FLR40S / 36 lamp does not decrease, and the FHF32 lamp It changes from the resonance curve almost in the form of horizontal movement. For this reason, the operating frequency difference Δfc1 in this example tends to be smaller than the operating frequency difference Δfc0 of the conventional apparatus.
Furthermore, since the peak of the resonance curve hardly changes, both lamps can be designed to be close to the natural vibration frequency, and the reactive current can be reduced as compared with the conventional device, so that an efficient operation can be realized.

2) Filament preheating current If Further, in the discharge lamp lighting device DLA of this example , since the difference Δfc1 in operating frequency is smaller than the difference Δfc0 in operating frequency of the conventional device, two types of discharge lamps LA were lit. Design that satisfies both lamp life and circuit efficiency, such that the difference ΔIfc1 in the filament preheating current at the time is small and sufficient preheating current is obtained in any discharge lamp while preheating current is suppressed. Made it easier. As a result, it is possible to suppress the normal preheating current while optimizing the preheating conditions.

3) Switching loss Similarly, since the difference Δfc1 in the operating frequency is small, the switching loss at the time of FHF32 lamp load, which was a conventional problem, can be suppressed.
From the above, the discharge lamp lighting device DLA of the present example is designed to be highly efficient without degrading circuit efficiency in addition to making the output power substantially constant for a plurality of discharge lamps LA having different rated powers. In addition, the life of the discharge lamp LA can be extended by obtaining appropriate filament preheating conditions .

(Assumption 2)
FIG. 13 is a circuit diagram of the discharge lamp lighting device according to the precondition 2 . The discharge lamp lighting device DLA having the precondition 2 is different in the configuration of the inverter load circuit IL from the basic configuration of FIG. The inverter load circuit IL is connected between Vs-Gnd, which is the output of the inverter circuit IV, and supplies a double resonance circuit DRC that supplies power to the two discharge lamp load circuits LA1, LA2 connected in series, and the discharge lamp filament ft1. , Ft2, ft3, and ft4 are configured by a preheating circuit PHC for preheating.

In the double resonance circuit DRC, the primary winding n1 of the resonance inductor L1 and the resonance capacitor C1 are connected in series between Vs and GND, which is the output of the inverter circuit IV, and are connected in series to both ends of the capacitor C1. The discharge lamp loads LA1 and LA2 and the resonance / DC blocking capacitor C2 are connected in series.
The preheating circuit PHC is configured by connecting the secondary windings n2, n3, and n4 of the resonance inductor T3 to the discharge lamp filaments ft1, ft2, ft3, and ft4 via capacitors C3, C4, and C19, respectively. .
In addition, the same code | symbol is attached | subjected to the component same as the basic composition of FIG. 1, and the overlapping description is abbreviate | omitted. Since the operation other than the inverter load circuit IL is the same as that of the basic configuration of FIG.

  Focusing on the preheating circuit of the discharge lamp filaments ft1, ft2, ft3, and ft4, the secondary windings n2, n3, and n4 of the inductor L1 are used as the power source of the preheating circuit, and the secondary windings n2, n3, and n4 of the inductor L1 are connected to the secondary windings n2, n3, and n4. Since the generated voltage is proportional to the voltage generated in the primary winding n1 of the inductor L1, the preheating current curve at the time of no load changes substantially along the resonance curve of the double resonance circuit DRC. At the time of lighting, the impedance change due to the frequency change of the capacitors C3, C4, C19 of the preheating circuit is larger than the voltage change of the inductor L1, and the preheating current decreases due to the increase of the impedance of the capacitors C3, C4, C19 when the frequency decreases. To do. Therefore, the curve is a left-down curve as shown in FIG. This preheating current curve can change the slope of the frequency characteristic according to the turns ratio of the inductor L1 and the constants of the capacitors C3, C4, and C19.

In this example , the capacitance ratio between the capacitors C1 and C2 is set so that the capacitance of the capacitor C2 is 20 times or less than the capacitance of the capacitor C1, and the operating frequency f is a characteristic such that f0 ≦ f ≦ f0 + 30 KHz in any lamp. In addition, the difference Δf between the operating frequency at the time of FHF32 and the frequency at the time of FLR40S / 36 could be set to Δf <10 KHz .

Example 1
FIG. 14 is a circuit diagram of the discharge lamp lighting device according to the first embodiment. In this embodiment, the input signal of the feedback control circuit FBC is partially changed in the circuit of the precondition 2 shown in FIG. 13, and the inverter load is connected to the negative input terminal of the operational amplifier OP1 for feedback control. The voltage of the resistor R1 that detects the resonance current of the circuit IL is input via the resistor R20.

In the premise configuration 2 , since the feedback resistor R1 is inserted between the switching element Q2 and GND, the resonance current flowing through the inductor T1, the capacitors C1 and C2, the lamp load, and the current flowing through the preheating circuit PHC The combined current is detected, and an error has occurred in the feedback control for making the output power constant. In the present embodiment, the resistor R1 is inserted by inserting the feedback resistor R1 at the position shown in FIG. Therefore, only the resonance current of the inverter load circuit IL flows, and accurate feedback control is possible.
(Prerequisite configuration 3)

FIG. 15 is a circuit diagram of a discharge lamp lighting device according to Configuration 3 as a premise . In Configuration 3 , which is the premise , a step-down chopper circuit DVC is added to the DC power supply circuit CV. That is, a series connection circuit of an inductor L1, an electrolytic capacitor C21, and a switching element Q5 is connected in parallel to both ends of the output capacitor C5 of the boost chopper circuit UVC, and a connection point between the electrolytic capacitor C21 and the switching element Q5 and the output capacitor C5, A diode D8 is connected between the connection points of the inductor L1 with the capacitor C12 and the switching element Q5 side as an anode, and the step-down chopper circuit DVC is configured by the inductor L1, the electrolytic capacitor C21, the switching element Q5, and the diode D8.

Here, the operation of the step-down chopper circuit DVC will be briefly described. The step-down chopper circuit DVC receives a predetermined smoothing voltage Vdc stored in the output capacitor C5 of the step-up chopper circuit UVC and inputs a predetermined smoothing voltage lower than the output capacitor C5 to the electrolytic capacitor C21 by repeatedly turning on and off the switching element Q5. Vdc ′ is created. The switching element Q5 is connected to the 8th pin (low voltage side drive voltage output terminal) of IVDR, which is an inverter control IC, via a resistor R27, and is repeatedly turned on and off in synchronization with the drive of the inverter low voltage side switching element Q2. . When the switching element Q5 is turned ON, a current flows from the smoothed voltage Vdc of the output capacitor C5 through the inductor L1, the electrolytic capacitor C21, and the switching element Q5. Thereafter, when the switching element Q5 is turned OFF, the energy stored in the inductor L1 is released through the electrolytic capacitor C21 and the diode D8.
As described above, by using a combination of the step-up chopper circuit and the step-down chopper circuit in the DC power supply circuit CV, it is possible to realize further higher efficiency without reducing the input harmonic suppression performance of the step-up chopper circuit .

(Assumption 4)
FIG. 16 is a circuit diagram of the discharge lamp lighting device according to Configuration 4 as a premise . The discharge lamp lighting device DLA having the precondition 4 has a DC power supply circuit CV for converting a commercial AC power supply SV into a predetermined DC smoothed voltage, and an inverter circuit IV is connected to the output side of the DC power supply circuit CV. The inverter load circuit IL is connected to the output side of the inverter circuit IV. Further, a control circuit CVCC that controls on / off driving of the switching element Q3 of the DC power supply circuit CV at high frequency, a control circuit IVCC that controls on / off driving of the switching elements Q1 and Q2 of the inverter circuit IV at high frequency, and inverter control thereof. A control circuit CC including a feedback circuit FBC that detects the resonance current and voltage of the inverter load circuit IL and feeds back to the control of the inverter control circuit IVCC is connected to the circuit IVCC. In this example , a PFC control unit for CVCC control, an INV control unit for IVCC control, an FBC control unit for FBC control, a driver circuit DRV for driving Q1 and Q2, and preheating when starting a discharge lamp Control is performed using an IC in which a timer circuit TIM or the like for controlling time is integrated in one wafer chip or one package. Further, the circuit ground Gnd of the discharge lamp lighting device DLA is connected to the ground E / G via the capacitor C17.

Next, the configuration and operation of each constituent circuit block of the discharge lamp lighting circuit DLA will be briefly described.
1) DC power circuit CV
The DC power supply circuit CV has a parallel connection of an input of a filter circuit FI that removes high frequency components generated by an inverter and the like, and a surge voltage absorbing element ZNR that absorbs a surge voltage input from the commercial power supply SV, at both ends of the commercial power supply SV. The connected circuit is connected via a current fuse Fuse that immediately cuts off the circuit from the AC power supply SV when the power supply is short-circuited due to a failure or the like in the discharge lamp lighting device DLA, and the AC voltage is applied to the output terminal of the filter circuit FI. The input of the rectifier DB to be rectified is connected, and the inrush current suppression circuit ICC and the series circuit of the input terminals of the boost chopper circuit UVC are connected to the output of the rectifier DB. Further, the switching element Q3 of the step-up chopper circuit UVC is connected to a control circuit CVCC that controls on / off driving of the switching element Q3 at a high frequency.

Here, the configuration and operation of the boost chopper circuit UVC and its control circuit CVCC will be briefly described.
The step-up chopper circuit UVC inputs the voltage via the inrush current suppression circuit ICC to the + output of the rectifier DB, and the primary winding n1 of the inductor T2 and the capacitor C8 are connected to the other end of the primary winding n1 of the inductor T2. Is connected to the drain terminal of the switching element Q3 and the anode of the diode D5, the source terminal of the switching element Q3 is connected to the current detection resistor R2 of the switching element Q3, and the cathode of the diode D5 is connected to the smoothing capacitor C5. The capacitor C8, the resistor R2, the other end of the capacitor C5, and the negative terminal of the rectifier DB are connected to the circuit ground Gnd so as to output a predetermined smoothing voltage Vdc to the capacitor C5.

  The control circuit CVCC is controlled by the PFC control unit in the control unit IC, and a voltage obtained by dividing the smoothed output voltage Vdc by the series circuit of the resistor R14 and the variable resistor VR1 from the smoothing capacitor C5 is used as an output voltage feedback signal. The parallel connection circuit of the resistor R10 and the capacitor C11 is input to the error amplifier output / compensation unit. Further, the voltage obtained by dividing the pulsating voltage of the chopper input voltage (the voltage across the capacitor C8) by the resistors R7 and R8 is smoothed by the capacitor C10 and input to the multiplier input unit. The current flowing through the switching element Q3 is detected by the resistor R2, and the voltage obtained by the resistor R2 is smoothed by the capacitor C12 via the resistor R13 and input to the current sense input unit.

  The inductor T2 is provided with a secondary winding n2 for detecting the zero cross point of the current flowing through the inductor T2, and its output is input to the zero current detection input section via the resistor R9. The output terminal of the PFC control unit is connected to the gate of the switching element Q3 via a resistor R12, and outputs an ON / OFF signal at a predetermined time according to each input signal. With the boost chopper control operation described above, it is possible to suppress input current harmonic distortion and to control the smoothed output voltage Vdc substantially constant against voltage fluctuations of the power supply SV.

  Next, the configuration and operation of the inrush current suppression circuit ICC will be briefly described. The inrush current suppression circuit ICC includes a PTC thermistor PTH and a thyristor Q4 connected in parallel. Between the gate and the cathode of the thyristor Q4, a series circuit of the secondary winding n3 of the inductor T2, a resistor R6 and a diode D2, and a resistor R5 And a capacitor C7 are connected in parallel. As for the operation of the inrush current suppression circuit ICC, since a voltage is generated in the secondary winding n3 of the inductor T2 during the operation of the boost chopper circuit UVC, the thyristor Q4 is turned on and current is supplied to the boost chopper circuit UVC through the thyristor Q4. When the boost chopper circuit UVC is not operating, almost no voltage is generated in the secondary winding n3 of the inductor T2, so that the thyristor Q4 is turned off and current is supplied to the boost chopper circuit UVC through the PTC thermistor PTH. In other words, since the boost chopper circuit UVC does not operate when the power is turned on, the inrush current is suppressed by the PTC thermistor PTH. In normal operation, the boost chopper circuit UVC operates, and the PTC thermistor PTH is short-circuited by the thyristor Q4. The circuit operation is such that no loss is caused by the thermistor.

2) Inverter circuit IV
The inverter circuit IV receives the output terminal of the DC power supply circuit CV (smoothed output voltage Vdc of the capacitor C5), and the output terminal of the DC power supply circuit CV is connected to the drain terminal of the switching element Q1. The drain terminal of the switching element Q2 is connected to the source terminal, the detection resistor R1 of the feedback circuit FBC is connected to the source terminal of the switching element Q2, and the resistance R1 is connected to the circuit ground GND. The gate terminals of the switching elements Q1 and Q2 and the output terminal VS of the inverter circuit IV are connected to the control circuit IVCC.

The control circuit IVCC includes an inverter control unit in the IC, a driver DVR, a timer circuit TIM, and peripheral components thereof.
Hereinafter, the configuration and operation of the peripheral parts of the inverter control circuit and the timer circuit TIM will be described.
The inverter control circuit is connected to a variable resistor VR2 for setting an operating frequency, a series circuit of a switch SW2 and a resistor R23, a series circuit of a switch SW1 and a resistor R24, and an oscillator capacitor C15. A signal is transmitted to the driver DRV. The driver DRV is connected to Vs as a COM terminal for high-voltage side driving. Further, a series circuit of a diode D5 and a capacitor C14 is connected between Vcc and COM, and the high-voltage side driving power source is stored in the capacitor C14. Switching elements Q2 and Q1 are connected to the driver DRV via resistors R18 and R16 on the low voltage side and the high voltage side, respectively, and the switching elements Q1 and Q2 are alternately turned on and off at the predetermined frequency.

The timer circuit TIM is connected to a resistor R25, connected to a capacitor C15, and starts operating with a time constant determined by the resistor R25 and the capacitor C15, and controls the on / off switching time of the switches SW1 to SW3.
Specifically, the oscillation operation is performed at a predetermined cycle determined by a mode changing in the sequence shown in FIG. By changing the operating frequency of the inverter control unit by turning on / off the switches SW1 to SW3, preheating and starting time at the time of starting the discharge lamp are set. Further detailed operation will be described below.

  First, when the inverter is started, the switch SW1 is turned on, the switch SW2 is turned on, and the switch SW3 is turned off. The inverter control unit, which is a constant voltage source, controls the currents IVR2, IR23 to the variable resistor VR2, resistors R23, R24, IR24 flows, and the resultant current: I1 = IVR2 + IR23 + IR24 is transmitted to the capacitor C15 at a predetermined magnification n × I1 through the inverter control unit, and the charging current IC15charge and discharging current IC15discharge of the capacitor C15 are determined, and charging / discharging of the capacitor C15 is performed. The period, that is, the preheating mode operating frequency fa of the inverter is determined.

  Next, when the preheating mode is finished, the switch SW1 is turned off, the switch SW2 is turned on, and the switch SW3 is turned off, and the current IR24 flowing through the resistor R24 is cut off. A combined current IVR2 + IR23 of the variable resistor VR2 and the resistor R23 flows through the inverter control unit, and is transmitted to the capacitor C15 in the same manner as described above, and the inverter frequency changes to the start mode frequency fb.

When the start mode ends, the switch SW1 is turned off, the switch SW2 is turned off, and the switch SW3 is turned on, and the current I23 that was flowing through the resistor R23 is cut off. A current IVR2 to the variable resistor VR2 and a combined current IVR2 + IFBC of the current IFBC flow to the feedback control circuit FBC including the switch SW3, the resistor R22, the diode D6, the operational amplifier OP1, and the like through the inverter control unit, and similarly to the above, to the capacitor C15. The frequency of the inverter is changed to the lighting mode frequency fc (when there is no current to the feedback control circuit FBC side) and fc ′ (when there is a current to the feedback control circuit FBC side).
The inverter circuit IV is driven while changing the frequency step by step from the preheating mode (frequency fa), the start mode (frequency fb), the lighting mode (frequency fc), and the feedback control start (frequency fc ′) by the above timer control. Can do.

  Next, the operation of the feedback control circuit FBC will be described. In the control unit of the feedback control circuit FBC, the voltage of the resistor R1 for detecting the current of the switching element Q2 of the inverter circuit IV is passed through the resistor R20, and the voltage generated in the auxiliary winding n2 of the inductor T1 is connected to the resistor R28. Is input via. The FBC control unit output terminal is connected to a connection point between the inverter control unit and the variable resistor VR2 via a diode D6, a resistor R22, and a switch SW3.

  In the operation of the feedback control circuit FBC, the resonance current of the inverter load circuit IL is converted into a voltage by a resistor R1 that detects a current flowing through the switching element Q2 of the inverter circuit IV, and this voltage is input via the resistor R20. Further, the voltage across the inductor T1, which shows a characteristic substantially proportional to the lamp voltage, is detected by the auxiliary winding n2, and is input via the resistor R28. That is, a combined signal of the current on the switching element Q2 side and the voltage of the inductor T1 is input to the FBC control unit, and the current IFBC flowing through the switch SW3, the resistor R22, and the diode D6 changes according to this signal, and the inverter circuit IV It has the function of changing the operating frequency of. The ratio of transmission to the FBC control unit of the current of the switching element Q2 indicating the movement following the load power and the voltage of the inductor T1 indicating the movement following the lamp voltage can be varied by the constants of the resistors R20 and R28. By changing the ratio of the feedback current, it is possible to perform a power control operation according to the application and the use environment.

As described above, the feedback control circuit FBC does not operate in the preheating and starting modes by the switch SW3 of the timer circuit TIM, as shown in FIG. 8, and in the lighting mode, between fcα and fcβ depending on the type of the discharge lamp load LA. Then, the operation of changing the operating frequency of the inverter circuit IV is performed so that the output power of the discharge lamp load LA has a predetermined characteristic .

(Example 2)
In the present embodiment, the configuration of a lighting fixture equipped with the above-described discharge lamp lighting device is illustrated. FIGS. 17 and 18 are image diagrams of a general Fuji-type lighting fixture for two lamps capable of lighting two discharge lamps. In the figure, S1 to S4 are sockets, R is a reflector, S is a spring, and H is a lamp pin contact hole. As the discharge lamp lighting device, one discharge lamp lighting device for two lamps as shown in FIGS. 13 to 16 or two discharge lamp lighting devices for one lamp as shown in FIG. 1 are mounted.

For example, the five types of discharge lamps FHF32, FL40S, FL40SS / 37, FLR40S, and FLR40S / 36 listed in Table 1 have the same tube length (1198 m) and the same base size (G13 type). 17 and 18 can be shared by one type of lighting fixture.

As a result, the luminaire user can use the lamp without worrying about the type of the discharge lamp, and the discharge lamp can be selected according to the user's preference (discharge lamp cost, design, light output, etc.). In this embodiment, the lighting fixture is for two lamps, but the number of discharge lamps and the number of lamps that can be lit by the discharge lamp lighting device are not limited .

(Example 3)
In this embodiment, a lighting system that collectively controls a plurality of lighting fixtures described in the second embodiment with a control device will be described. Twelve lighting fixtures A to L described in the second embodiment are connected to a human body sensor and a control device including a program controllable system. In the present embodiment, FHF 32 is mounted as a lamp load on lighting fixtures A to I, and FLR 40/36, which has a lower luminous flux than FHF 32 but is cheaper, is installed on lighting fixtures J to L on the window side where external light enters. . As a feature of this control device, it is possible to set a function to turn on the discharge lamp when a person is detected by the human body sensor and to turn it off when there is no person, input the load installation status, turn on any lighting fixture, and turn off conditions This is a highly efficient and energy-saving lighting system according to the installation environment without changing the power load on the control device by combining with the above-described discharge lamp lighting device. Can be realized.

  The present invention can be used for lighting equipment and lighting systems for offices and general homes.

It is a circuit diagram which shows the detailed structure of the structure 1 used as the premise of this invention. It is a circuit diagram which shows the prior art example 1. FIG. It is a circuit diagram which shows the prior art example 2. It is the 1st explanatory view of the resonance circuit used for the present invention. It is the 2nd explanatory view of the resonance circuit used for the present invention. It is explanatory drawing of the resonance operation | movement of the prior art example 1 of FIG. It is explanatory drawing of the resonance operation | movement of the prior art example 2 of FIG. It is explanatory drawing of the preheating of this invention, starting, and lighting mode. It is a 1st operation | movement waveform diagram which shows the operation | movement waveform of each part of this invention. It is a 2nd operation | movement waveform diagram which shows the operation | movement waveform of each part of this invention. It is a 3rd operation | movement waveform diagram which shows the operation | movement waveform of each part of this invention. It is an operation | movement waveform diagram for demonstrating the switching loss of this invention. It is a circuit diagram which shows the detailed structure of the structure 2 used as the premise of this invention. It is a circuit diagram which shows the detailed structure of Example 1 of this invention. It is a circuit diagram which shows the detailed structure of the structure 3 used as the premise of this invention. It is a circuit diagram which shows the detailed structure of the structure 4 used as the premise of this invention. It is a perspective view of the lighting fixture of Example 2 of this invention. It is a bottom view of the lighting fixture of Example 2 of this invention.

Explanation of symbols

DLA discharge lamp lighting device LA discharge lamp CV DC power supply circuit IV inverter circuit IL inverter load circuit PHC preheating circuit DRC double resonance circuit CC control circuit IVCC inverter control circuit CVCC chopper control circuit FBC feedback control circuit

Claims (8)

A DC power supply, an inverter circuit connected to the DC power supply, a double resonance circuit connected to the inverter circuit, a discharge lamp supplied with power from the double resonance circuit, and a resonance current or resonance voltage of the double resonance circuit A discharge lamp lighting device comprising: a detection circuit for detecting; and a control circuit for varying an operating frequency of the inverter according to a detection value of the detection circuit, wherein the double resonance circuit includes a first inductor in the inverter A first resonant circuit constituted by a series connection of a first capacitor is connected in parallel, a series connection circuit of a second capacitor and the discharge lamp is connected in parallel to the first capacitor, a first inductor, 2 and a second resonance circuit composed of a discharge lamp, and a preheating circuit for preheating the filament of the discharge lamp has a second input circuit separate from the double resonance circuit. A detection circuit configured to supply a preheating current from an auxiliary winding of a second inductor by connecting a third resonance circuit by a series connection of a capacitor and a third capacitor in parallel to the inverter; The discharge lamp lighting device has a plurality of discharge lamps with different rated powers as applicable loads, and is configured to detect a current obtained by excluding a current flowing through the preheating circuit from a current flowing through a switching element included in the inverter circuit. A discharge lamp lighting device, wherein an operating frequency when an electric lamp is turned on is controlled to be a predetermined value or less. The operating frequency is said first inductor, claim 1, the first capacitor, to the natural vibration frequency f0 determined by the impedance of the discharge lamp in which the second capacitor, and connected, characterized in that the f0 ≦ f ≦ f0 + 30 KHz The discharge lamp lighting device described. It said first, capacity ratio of the second capacitor discharge lamp lighting device according to claim 1, wherein a capacitance of the second capacitor to the first capacitor is set to 20 times or less. The discharge lamp lighting device according to any one of claims 1 to 3 , wherein the discharge lamp is a plurality of different types of discharge lamps having substantially the same length. Wherein the discharge lamp is substantially the same length, substantially a same die dimensions, claim 1-4, characterized in that the discharge lamp of the plurality heterogeneous available at substantially the same luminaire The discharge lamp lighting device according to 1. The discharge lamp lighting device according to any one of claims 1 to 5, wherein said discharge lamp is characterized in that the difference △ f of frequency when the operating frequency and FLR40S / 36 when the FHF32 that △ was f <10 KHz. Wherein the discharge lamp is substantially the same length, substantially a same die dimensions, claim 1-6, characterized in that the discharge lamp of the plurality heterogeneous available at substantially the same luminaire A lighting apparatus comprising the discharge lamp lighting device according to claim 1 and capable of selecting a discharge lamp according to the application. The lighting system carrying the lighting fixture of Claim 7 .

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