JP2005302429A - Discharge lamp lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable starting of lighting of a discharge lamp having a high starting voltage without impressing a pulse-like voltage at the starting, and suppresses generation of flash noise after the starting of lighting of the discharge lamp, and reduce unpleasant feeling. <P>SOLUTION: A resonance characteristics setting means which sets resonance characteristics of a resonance circuit part 3 at the starting is provided at a control circuit part 5 so that at the starting, the Q value of the resonance characteristics of the resonance circuit part 3 may become larger than that at the time of rated output lighting, and the frequency of an operating point of an inverter 1 and the resonance circuit part 3 may be higher than the non-load resonance frequency and may become the frequency in the vicinity of non-load resonance frequency and at the lowest, the frequency corresponding to the starting voltage of the discharge lamp FL, and so that at the starting of lighting, the frequency of the operating point of the inverter 1 and the resonance circuit part 3 may correspond to the frequency of the operating point corresponding to the light output level at the lower limit of light control of the discharge lamp FL. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a discharge lamp lighting device having a dimming function.

  Conventionally, this type of discharge lamp lighting device generally has a chopper that converts AC power of commercial power into DC power, and converts DC power from the chopper into high-frequency power and supplies it to a discharge lamp (fluorescent lamp). And an inverter and a resonance circuit unit.

  For example, Patent Document 1 includes a chopper and an inverter that operates earlier (including a resonant circuit portion in Patent Document 1), and intermittently applies a pulse voltage sufficient to start a discharge lamp. Disclosed is a discharge lamp lighting device including voltage applying means.

In this discharge lamp lighting device, during preheating after turning on the power, the boost chopper is not operated, and the preheating is performed by operating the inverter after setting the output level of the chopper to the voltage peak value of the AC power supply. . At the time of starting after this, the chopper is operated to increase its output level to a predetermined constant level, and the voltage application means is operated to intermittently superimpose the gradually increasing pulse voltage on the output of the chopper, Bring the discharge lamp to start lighting. Here, the pulse voltage can be gradually increased by gradually increasing the change width of the drive frequency.
Japanese Patent No. 3324270

By the way, in the discharge lamp lighting device, the resonance circuit unit is connected to the output of the inverter together with the discharge lamp, so that, as shown in FIG. The resonance characteristic A automatically changes to the load resonance characteristic A2. This resonance characteristic A can ensure the rated output level of the discharge lamp (a level corresponding to the operating frequency f _Dmax ) for the load resonance characteristic A2 that automatically changes from the no-load resonance characteristic A1 when the discharge lamp is started and lit. It is set to be possible.

Here, when the discharge lamp lighting device operates at the operating point A11 corresponding to the start operating frequency f _str at the start, the discharge lamp is started and lit. However, as shown in the example of FIG. It is assumed that the voltage is low and the operating point at the time of starting lighting is the operating point A20 of the operating frequency f _Dmin corresponding to the dimming lower limit. In this case, the dark state of the ambient illuminance is instantaneously switched to the bright state at the light control lower limit, and this bright state is maintained. Alternatively, the dark state of the ambient illuminance is instantaneously switched to the bright state at the lower limit of dimming, and this bright state is instantaneously switched to the bright state of the dimming state set by the dimmer, and this bright state is maintained. It will be. In any of these cases, the dark state switches to the bright state (almost) in the same way as when switching from the dark state to the general all-lit bright state instantly, so that the user does not feel uncomfortable. The starting lighting of the discharge lamp is possible.

On the other hand, as shown in FIG. 15, when the rated output of the discharge lamp is 42 W, for example, and the starting voltage is high, for example, about 550 V, the user may feel uncomfortable. That is, as shown in the example of FIG. 15, when the starting voltage of the discharge lamp is high, the operating point at the operating frequency f _str at the start lighting is higher than the light output level corresponding to the operating point A20 at the operating frequency f _Dmin. It becomes the operating point A21 of the light output level. In this case, if the dimmer is set to a dimming state with a dimming lower limit of 30% or less of the rated output, for example, the bright state in which the dark state of the ambient illuminance instantaneously increases to the light output level of the operating point A21 This bright state is instantaneously switched to a bright state that falls to the light output level (A20) at the lower limit of the dimming set by the dimmer, and this bright state is maintained. As described above, when the light output level instantaneously increases to the light output level of the operating point A21 and decreases to the light output level of the operating point A20, which is the lower limit of dimming, it appears as if a flash has occurred, which is noise (hereinafter referred to as “flash”). Noise ”), and the flash noise causes the user to feel uncomfortable. 14 and 15, f ₀ is a no-load resonance frequency, A 10 is an operating point at the time of preheating, and at the time of starting, the operating frequency is the operating frequency f for starting from the operating frequency side for preheating at the operating point A 10. Swept into _str (see arrow).

  The unpleasant feeling given to the user by such flash noise can be reduced by the discharge lamp lighting device of Patent Document 1. In this discharge lamp lighting device, the predetermined constant level, which is increased during chopper operation, is increased by intermittently superimposing the gradually increasing pulse voltage on the output of the chopper by operating the voltage applying means. It can be made lower than the voltage. As a result, the overall level of the load resonance characteristic that changes automatically when the discharge lamp starts is lowered, so that the light output level corresponding to the operating point at the time of start lighting can be lowered. The difference from the lower limit light output level can be reduced.

  However, the discharge lamp lighting device of Patent Document 1 has a problem in that deterioration of the discharge lamp (filament) progresses because a gradually increasing pulse voltage is applied to the discharge lamp several times during startup. .

  The present invention has been made in view of the above circumstances, and does not apply a gradually increasing pulse voltage to the discharge lamp at the time of start-up, and even if it is a discharge lamp with a high start-up voltage, it is started and lit. An object of the present invention is to provide a discharge lamp lighting device that can suppress the generation of flash noise after starting and lighting the discharge lamp and can reduce discomfort to the user due to the flash noise.

  The invention according to claim 1 for solving the above-described problem is that an inverter constituted by a switching element, a DC power supply for supplying DC power to the inverter, and an output of the inverter are connected together with a discharge lamp, The discharge lamp has a resonance characteristic that automatically changes to a no-load resonance characteristic or a load resonance characteristic when the discharge lamp is turned off or on, respectively, and is connected to the DC power source from the DC power source in conjunction with the ON / OFF operation of the switching element of the inverter. A discharge lamp lighting device comprising: a resonance circuit unit that converts electric power into high-frequency power and supplies the high-frequency power to the discharge lamp; and a dimming setting unit that sets a dimming state of the discharge lamp; At the time of starting the electric lamp, the Q value of the resonance characteristic of the resonance circuit unit is higher than the Q value of the resonance characteristic of the resonance circuit unit at the rated lighting of the discharge lamp. The frequency of the operating point of the inverter and the resonance circuit unit is higher than the no-load resonance frequency due to the no-load resonance characteristic, and corresponds to the frequency near the no-load resonance frequency and at least corresponds to the starting voltage of the discharge lamp. On the other hand, the frequency of the operating point of the inverter and the resonance circuit unit matches the frequency of the operating point corresponding to the light output level of the dimming lower limit of the discharge lamp when the discharge lamp is started and lit. And resonance characteristic setting means for setting a resonance characteristic of the resonance circuit unit at the time of starting.

  In this configuration, at the time of starting, the resonance characteristic of the resonance circuit unit at the time of starting is set so that the Q value of the resonance characteristic of the resonance circuit unit is larger than that at the time of rated lighting. It is possible to reduce the light output level of the discharge lamp during start-up lighting so that the frequency of the operating point matches the frequency corresponding to the light output level at the lower limit of dimming. As a result, even if the voltage level due to the no-load resonance characteristic at the time of starting is lower than that of the conventional one, the frequency of the operating point at the time of starting is higher than the no-load resonance frequency and the frequency near the no-load resonance frequency In both cases, the resonance characteristic of the resonance circuit section at the time of starting is set so that the frequency corresponds to the starting voltage of the discharge lamp, so that even a discharge lamp having a high starting voltage can be started and lit. Furthermore, at the time of starting lighting, the resonance characteristic of the resonance circuit unit at the time of starting is set so that the frequency of the operating point matches the frequency of the operating point corresponding to the light output level at the dimming lower limit of the discharge lamp. Generation of flash noise after the start-up of the discharge lamp can be suppressed, and discomfort to the user due to flash noise can be reduced.

  According to a second aspect of the present invention, an inverter configured by a switching element, a DC power source that supplies DC power to the inverter, and an output of the inverter together with a discharge lamp, the discharge lamp is turned off or Resonance characteristics that automatically change to no-load resonance characteristics or load resonance characteristics in the lighting state, respectively, and convert DC power from the DC power source to high-frequency power in conjunction with the ON / OFF operation of the switching element of the inverter. A discharge lamp lighting device comprising a resonance circuit unit for supplying the high-frequency power to the discharge lamp, and a dimming setting means for setting a dimming state of the discharge lamp, and at the start of the discharge lamp, The Q value of the resonance characteristic of the resonance circuit unit is larger than the Q value of the resonance characteristic of the resonance circuit unit when the discharge lamp is rated for lighting. And the frequency of the operating point of the resonance circuit unit is higher than the no-load resonance frequency due to the no-load resonance characteristic and near the no-load resonance frequency, and at least the frequency corresponding to the starting voltage of the discharge lamp, When the discharge lamp is started and lit, the frequency of the operating point of the inverter and the resonance circuit unit is the frequency of the operating point corresponding to the light output level in the dimming state set by the dimming setting means or higher than this. Resonance characteristic setting means for setting the resonance characteristic of the resonance circuit section at the time of starting so as to have a high frequency.

  In this configuration, at the time of starting, the resonance characteristic of the resonance circuit unit at the time of starting is set so that the Q value of the resonance characteristic of the resonance circuit unit becomes larger than that at the time of rated lighting. The light output level of the discharge lamp at the time of starting lighting can be lowered so that the frequency of the operating point matches the frequency corresponding to the light output level in the dimming state set by the dimming setting means or a higher frequency. it can. As a result, even if the voltage level due to the no-load resonance characteristic at the time of starting is lower than that of the conventional one, the frequency of the operating point at the time of starting is higher than the no-load resonance frequency and the frequency near the no-load resonance frequency. In both cases, the resonance characteristic of the resonance circuit section at the time of starting is set so that the frequency corresponds to the starting voltage of the discharge lamp, so that even a discharge lamp having a high starting voltage can be started and lit. Further, at the time of starting lighting, resonance at the time of starting so that the frequency of the operating point becomes the frequency of the operating point corresponding to the light output level in the dimming state set by the dimming setting means or higher than that. Since the resonance characteristic of the circuit unit is set, generation of flash noise after the start-up of the discharge lamp can be suppressed, and discomfort to the user due to flash noise can be reduced.

  According to a third aspect of the present invention, in the discharge lamp lighting device according to the first or second aspect, the resonance characteristic setting means sets at least one of an output voltage of the DC power supply and an on-duty of a switching element of the inverter. Thus, the resonance characteristic of the resonance circuit section at the time of starting is set. Even with this configuration, it is possible to start and light even a discharge lamp with a high starting voltage without applying a gradually increasing pulse voltage to the discharge lamp at the start, and after starting the discharge lamp. It is possible to suppress the occurrence of flash noise in, and to reduce discomfort to the user due to flash noise.

  According to a fourth aspect of the present invention, in the discharge lamp lighting device according to any one of the first to third aspects, when the discharge lamp is started, the frequency of the operating point of the inverter and the resonance circuit unit is the no-load resonance. A starting control signal for controlling the on / off operation of the switching element of the inverter is output to the switching element so as to sweep from the preheating operating frequency side higher than the frequency to the no-load resonance frequency side. To do. In this configuration, the discharge lamp can be started and lit with the minimum required starting voltage without applying excessive stress.

  According to a fifth aspect of the present invention, in the discharge lamp lighting device according to any one of the first to fourth aspects, the inverter is a half bridge circuit in which the switching elements are connected in series between both output terminals of the DC power supply. The resonance characteristic setting means is configured to set an on-duty ratio of a start control signal for controlling an on / off operation of each switching element of the half-bridge circuit, so that the resonance circuit unit at the time of start-up The resonance characteristic is set. In this configuration, there is no need to control the output voltage of the DC power supply, and only the inverter control is required, so the control configuration of the DC power supply is simplified, and there is no need to configure the DC power supply with a buck-boost chopper or the like. Cost reduction is possible.

  According to a sixth aspect of the present invention, in the discharge lamp lighting device according to the first or second aspect, the inverter is a first switching element as the switching element between a positive output terminal and a negative output terminal of the DC power supply. And the second switching element are connected in series, and the third switching element and the fourth switching element are connected in series, respectively, and the resonance characteristic setting means includes the first switching element and the fourth switching element. By setting the phase shift amount of the on-timing of the switching element and the phase shift amount of the on-timing of the second switching element and the third switching element, the resonance characteristic of the resonance circuit unit at the start is set It is characterized by. In this configuration, by controlling the amplitude of the current (lamp current) flowing through the discharge lamp according to the phase shift amount, the waveform of the lamp current is not distorted, so that noise countermeasures are facilitated.

  According to a seventh aspect of the present invention, in the discharge lamp lighting device according to the first or second aspect, the frequency of the operating point of the inverter and the resonance circuit unit at the start of the discharge lamp, at the time of start lighting, and after the start lighting is determined. The discharge lamp is maintained at a frequency higher than the no-load resonance frequency and in the vicinity of the no-load resonance frequency, and the light output of the discharge lamp corresponds to a dimming state set by the dimming setting means after the discharge lamp is started and lit. The discharge lamp is dimmed by adjusting at least one of the output voltage of the DC power supply and the on-duty of the switching element of the inverter so as to achieve a light output level. In this configuration, a similar lamp current can be supplied to discharge lamps having different rated powers. In particular, discharge lamps having substantially the same rated current can be lit in a dimming state that is substantially equal.

  The invention according to claim 8 is the discharge lamp lighting device according to claim 1 or 2, wherein any one of a current flowing through the discharge lamp, electric power supplied to the discharge lamp, and a switching current of the switching element is detected. Detecting means for outputting a detection signal, and error amplifying means for amplifying an error between the detection signal and a signal that changes according to the dimming state set by the dimming setting means, and outputting an error signal. And adjusting at least one of the frequency of the operating point of the inverter and the resonance circuit unit and the on-duty of the switching element of the inverter according to the error signal output by the error amplifying means. It is characterized by dimming. In this configuration, a similar lamp current can be supplied to discharge lamps having different rated powers. In particular, discharge lamps having substantially the same rated current can be lit in a dimming state that is substantially equal.

  According to the present invention, it is possible to start and light even a discharge lamp having a high starting voltage without applying a gradually increasing pulse voltage to the discharge lamp at the time of starting. Generation of flash noise after lighting can be suppressed, and discomfort to the user due to flash noise can be reduced.

(Embodiment 1)
FIG. 1 is a configuration diagram of a discharge lamp lighting device according to a first embodiment of the present invention, and FIG. 2 is an operation explanatory diagram of the discharge lamp lighting device.

  The discharge lamp lighting device of Embodiment 1 has a dimming function for dimming a discharge lamp FL whose start voltage and dimming lower limit level are known. As shown in FIG. 2, a resonance circuit unit 3, a dimmer 4, and a control circuit unit 5. Here, it is assumed that the discharge lamp FL has a rated output of, for example, 42 W, a high starting voltage of, for example, about 550 V, and a dimming lower limit level of, for example, a predetermined level of 30% or less of the rated output.

  The inverter 1 is constituted by a half bridge circuit in which a pair of switching elements Q11 and Q12 are connected in series between the positive output terminal and the negative output terminal of the DC power supply 2, respectively. In the example of FIG. 1, each of the switching elements Q11 and Q12 is a MOS FET having a parasitic diode connected in antiparallel, but may be configured by a bipolar transistor and a diode connected antiparallel to this. C1 is a DC cut capacitor.

  The DC power supply 2 supplies DC power to the inverter 1, and in the first embodiment, the output voltage level is adjusted according to a control signal from the control circuit unit 5. Such a configuration can be realized by, for example, a step-up / down chopper or a boost chopper.

  The resonance circuit unit 3 has a resonance characteristic that automatically changes to a no-load resonance characteristic or a load resonance characteristic when the discharge lamp FL is turned off or on by being connected to the output of the inverter 1 together with the discharge lamp FL. The DC power from the DC power source 2 is converted into high frequency power in conjunction with the on / off operation of each switching element of the inverter 1, and this high frequency power is supplied to the discharge lamp FL. In the example of FIG. 1, it is configured by an inductor L3 and a capacitor C3 connected in series to both ends of the switching element Q12 via a capacitor C1, and both filaments of the discharge lamp FL are interposed on both ends of the capacitor C3. It has become.

  The dimmer 4 sets the dimming state of the discharge lamp, and is configured to output a dimming signal according to an operation input by the user, for example.

  The control circuit unit 5 is configured by, for example, a PWM-IC and executes the overall control of the discharge lamp lighting device 1 and has various functions such as an inverter control function 5a and a DC power supply output control function 5b. Yes. The inverter control function 5a outputs a high-frequency control signal with variable switching frequency to each gate of the switching elements Q11 and Q12, and executes on / off control of the switching elements Q11 and Q12.

  The DC power supply output control function 5b outputs a control signal to the DC power supply 2 and executes level switching control of the output voltage of the DC power supply 2. Here, as a feature of the first embodiment, the DC power supply output control function 5b is configured to operate as a resonance characteristic setting unit.

As shown in FIG. 2, this resonance characteristic setting means sets the output voltage Vdc of the DC power supply 2 to 410 V in the same manner as in the prior art after pre-heating of the discharge lamp FL and after starting lighting including the rated lighting of the discharge lamp FL. By outputting a control signal for switching to an appropriate voltage to the DC power supply 2, the resonance characteristic of the resonance circuit unit 3 is set to the resonance characteristic A similar to the conventional one. Thereby, for example, when the discharge lamp FL is started, the control circuit unit 5 outputs a control signal for preheating to each gate of the switching elements Q11 and Q12, so that the switching elements Q11 and Q12 correspond to the preheating operating frequency f _pre . On / off operation is performed at the operating point A10, and electric power for preheating these is supplied to both filaments of the discharge lamp FL from the resonance circuit unit 3 interlocked with the on / off operation. In FIG. 2, A1 and B1 are no-load resonance characteristics, and A2 and B2 are load resonance characteristics.

Further, the resonance characteristic setting means is configured such that the Q value of the resonance characteristic B of the resonance circuit unit 3 at the time of starting the discharge lamp FL is higher than the Q value of the resonance characteristic A at the time of preheating or rated lighting after starting lighting. Is set so that the resonance characteristic of the resonance circuit unit 3 at the time of starting is set. Further, the resonance characteristic B is such that the starting operating frequency f _{str at} the operating point B11 of the inverter 1 and the resonance circuit unit 3 is higher than the no-load resonance frequency f ₀ due to the no-load resonance characteristic at the time of starting. The frequency is set to a frequency in the vicinity of f ₀ and at least a frequency corresponding to the starting voltage of the discharge lamp FL. In the example of FIG. 2, the frequency is set so as to correspond to the starting voltage of the discharge lamp FL. Further, the resonance characteristic B indicates that the starting operating frequency f _{str at} the operating point of the inverter 1 and the resonant circuit unit 3 corresponds to the light output level at the lower limit of dimming of the discharge lamp FL when the discharge lamp FL is started. It is set to match the frequency of the operating point B20. These series of settings are collectively performed by outputting a control signal for switching the output voltage Vdc of the DC power supply 2 to a voltage of about 80 V to the DC power supply 2.

Note that after the discharge lamp FL is started and lit, a control signal for switching the output voltage Vdc of the DC power supply 2 to a voltage of about 410 V is output to the DC power supply 2, so that the resonance characteristics of the resonance circuit unit 3 become the resonance characteristics A. In this case, the inverter control function 5a of the control circuit unit 5 causes the light output of the discharge lamp FL to reach the light output level corresponding to the light control state set by the light controller 4. Thus, the discharge lamp FL is dimmed (including full lighting) by outputting a control signal for controlling the frequency (operating frequency) of the operating point of the inverter 1 and the resonance circuit unit 3. In the example of FIG. 2, the light output range by dimming is a range corresponding to the load resonance characteristic A2 according to the operating frequency within f _str (= f _Dmin ) to f _Dmax .

Next, operations that characterize the first embodiment will be described. At the time of preheating, a control signal for switching the output voltage Vdc of the DC power source 2 to a voltage of about 410 V is output from the control circuit unit 5 to the DC power source 2 and preheated from the control circuit unit 5 to the gates of the switching elements Q11 and Q12. Control signal is output. Thereby, the resonance characteristic of the resonance circuit unit 3 is set to the resonance characteristic A, and the switching elements Q11 and Q12 are turned on and off at the preheating operating frequency f _pre , and the resonance circuit unit 3 interlocked with the on and off operations. Is supplied to both filaments of the discharge lamp FL.

At the time of starting the discharge lamp FL thereafter, a control signal for switching the output voltage Vdc of the DC power source 2 to a voltage of about 80 V is output from the control circuit unit 5 to the DC power source 2, and from the control circuit unit 5 to the switching element Q11. , Q12, start control signals are output to the respective gates. As a result, the resonance characteristic of the resonance circuit unit 3 is set to the resonance characteristic B, and the switching elements Q11 and Q12 are turned on and off at the starting operation frequency f _str , and the resonance circuit unit 3 interlocked with the on and off operations. A starting voltage is applied to the discharge lamp FL.

At the time of starting lighting of the discharge lamp FL thereafter, the no-load resonance characteristic B1 automatically changes to the load resonance characteristic B2, but the switching elements Q11 and Q12 are continuously turned on and off at the starting operating frequency _fstr. As a result, the discharge lamp FL is started and lit at the light output level at the lower limit of dimming (the level of the operating point B20).

  After starting and lighting, a control signal for switching the output voltage Vdc of the DC power source 2 to a voltage of about 410 V is output from the control circuit unit 5 to the DC power source 2, and each of the switching elements Q11 and Q12 from the control circuit unit 5 is output. A control signal corresponding to the dimming state set by the dimmer 4 is output to the gate. As a result, the discharge lamp FL is lit in a dimming state set by the dimmer 4. For example, if the dimmer 4 is set to the dimming state at the lower limit of dimming, the operating point is switched from B20 to A20.

As described above, according to the first embodiment, at the time of starting, the resonance characteristic B of the resonance circuit unit 3 has a higher Q value than that at the time of rated lighting or the like. Is set, the light output level of the discharge lamp FL during start-up lighting can be lowered so that the frequency f _str of the operating point B11 during start-up lighting matches the frequency corresponding to the light output level of the dimming lower limit. it can. As a result, even if the voltage level due to the no-load resonance characteristic B1 at the start is lower than that of the conventional one, the frequency f _str at the operating point at the start is higher than the no-load resonance frequency f ₀ and the no-load resonance frequency f _Since the resonance characteristic of the resonance circuit unit 3 at the time of starting is set so that the frequency is close to _{0 and} the frequency corresponding to the starting voltage of the discharge lamp FL, even a discharge lamp having a high starting voltage can be started. Can be lit. Further, the resonance characteristic of the resonance circuit unit 3 at the start is such that the frequency f _{str at} the operation point matches the frequency at the operation point B20 corresponding to the light output level at the lower limit of dimming of the discharge lamp FL at the time of starting lighting. Since it is set, generation of flash noise after the start-up lighting of the discharge lamp FL can be suppressed, and discomfort to the user due to flash noise can be reduced.

  As a modification of the first embodiment, a pair of secondary windings having the inductor L3 as a primary winding is further provided, and both filaments of the discharge lamp FL are connected to the pair of secondary windings, respectively. You may make it the structure which performs preheating. Or the structure which preheats a filament from a secondary winding via a capacitor | condenser may be sufficient.

As a modification of the first embodiment (and each embodiment described later), the frequency of the operating point of the inverter 1 and the resonance circuit unit 3 is higher than the no-load resonance frequency f ₀ when starting the discharge lamp FL. A starting control signal for controlling the on / off operation of the switching elements Q11 and Q12 is output to the gates of the switching elements Q11 and Q12 so as to sweep from the operating frequency f _pre side to the no-load resonance frequency f ₀ side. May be. In this configuration, the discharge lamp FL can be started and lit with the minimum required starting voltage without applying excessive stress. Further, even if the ambient temperature fluctuates or the starting voltage of the discharge lamp FL varies, the discharge lamp FL can be reliably started and lit. In this case, the flash noise after the start and lighting of the discharge lamp FL can be prevented. Generation | occurrence | production can be suppressed and the discomfort with respect to the user by flash noise can be reduced.

(Embodiment 2)
FIG. 3 is a configuration diagram of the discharge lamp lighting device according to the second embodiment of the present invention.

  As shown in FIG. 3, the discharge lamp lighting device according to the second embodiment includes a diode bridge DB, switching elements Q21 and Q22, diodes D21 and D22, and an inductor L2 as a specific example of the DC power supply 2 according to the first embodiment. A step-up / down chopper configured and a smoothing capacitor C2 are provided.

  The control circuit unit 5 of the second embodiment includes a control circuit unit 51 for the inverter 1 and a control circuit unit 52 for the DC power source 2 of the step-up / step-down chopper. The control circuit unit 51 and the control circuit unit 52 have an inverter control function 5a and a DC power supply output control function 5b (not shown). The control circuit unit 51 and the control circuit unit 52 are configured by, for example, a PWM-IC.

  The DC power supply output control function 5b provided in the control circuit unit 52 of the second embodiment is the same as that of the first embodiment in the operation after the start-up lighting including the preheating of the discharge lamp FL and the rated lighting of the discharge lamp FL. Although similar, the operation at the time of starting the discharge lamp FL is configured to operate as a resonance characteristic setting unit different from that of the first embodiment.

In this resonance characteristic setting means, when the discharge lamp FL is started, the Q value of the resonance characteristic B of the resonance circuit unit 3 is larger than the Q value of the resonance characteristic A at the time of preheating or rated lighting after starting lighting. Thus, the resonance characteristic of the resonance circuit unit 3 at the time of starting is set. Further, the resonance characteristic B is at the start, the starting operation frequency f _str operating point B11 of the inverter 1 and the resonance circuit section 3 is higher than the no-load resonance frequency f ₀ frequency of the no-load resonance frequency f ₀ near And at least a frequency corresponding to the starting voltage of the discharge lamp FL. As a feature of the second embodiment, the resonance characteristic B is a dimming state in which the frequency of the operating point of the inverter 1 and the resonance circuit unit 3 is set by the dimmer 4 when the discharge lamp FL is started. The frequency is set so as to match or be higher than the frequency of the operating point corresponding to the light output level. These series of settings are performed in a lump by outputting a control signal for switching the output voltage Vdc of the DC power supply 2 to a predetermined voltage to the DC power supply 2. That is, in the first embodiment, the output voltage Vdc of the DC power supply 2 is fixedly switched to a voltage of about 80 V as an example, whereas in the second embodiment, the dimming state set by the dimmer 4 is changed. The output voltage Vdc of the DC power supply 2 is adaptively switched to a predetermined voltage according to the optical output level.

  The control circuit unit 52 sets the resonance characteristic of the resonance circuit unit 3 by switching the output voltage Vdc of the DC power source 2 by outputting an on-duty control signal to the switching elements Q21 and Q22. When the resonance characteristic A is set, the voltage is switched to about 410 V higher than the peak voltage of the AC power supply AC. When the resonance characteristic B is set, the voltage is switched to a predetermined voltage lower than the peak voltage of the AC power supply AC. .

Next, an operation that characterizes the second embodiment will be described. At the time of starting the discharge lamp FL, a control signal for switching the output voltage Vdc of the DC power supply 2 to a predetermined voltage is output from the control circuit unit 52 to the DC power supply 2, and each of the switching elements Q11 and Q12 is supplied from the control circuit unit 51. A start control signal is output to the gate. As a result, the resonance characteristic of the resonance circuit unit 3 is set to the resonance characteristic B, the switching elements Q11 and Q12 are turned on and off at the starting operating frequency _fstr , and the starting voltage is applied to the discharge lamp FL.

At the time of starting lighting of the discharge lamp FL thereafter, the no-load resonance characteristic B1 automatically changes to the load resonance characteristic B2, but the switching elements Q11 and Q12 are continuously turned on and off at the starting operating frequency _fstr. As a result, the discharge lamp FL is started and lit at the light output level in the dimming state set by the dimmer 4.

  As described above, according to the second embodiment, it is possible to start and light a discharge lamp having a high starting voltage without applying a gradually increasing pulse voltage to the discharge lamp FL at the time of starting. Generation of flash noise after the start-up of the discharge lamp FL can be suppressed, and discomfort to the user due to flash noise can be reduced. Moreover, the number of times the illuminance changes instantaneously can be reduced by starting the discharge lamp FL at the light output level in the dimming state set by the dimmer 4 at the start lighting.

(Embodiment 3)
FIG. 4 is a configuration diagram of a discharge lamp lighting device according to a third embodiment of the present invention, and FIGS. 5 and 6 are operation explanatory diagrams of the discharge lamp lighting device.

  As shown in FIG. 4, the discharge lamp lighting device of Embodiment 3 is different from Embodiments 1 and 2, as shown in FIG. 4, a diode bridge DB, a step-up chopper configured by a switching element Q22, a diode D22, and an inductor L2. And a DC power source 2 including a smoothing capacitor C2, and instead of setting the output voltage Vdc of the DC power source 2, the resonance characteristic setting means sets the on-duty of each switching element of the inverter 1 at the time of starting. The resonance characteristic of the resonance circuit unit 3 is set to the resonance characteristic B.

  The DC power supply 2 is configured to always output a constant voltage Vdc. When the AC power supply AC is 100 V, the DC power supply 2 outputs a voltage Vdc of about 141 V or more, and when the AC power supply AC is 200 V, it is about 282 V. The above voltage Vdc is output.

  The resonance characteristic setting unit of the third embodiment is provided not in the control circuit unit 52 but in the control circuit unit 51, and the inverter control function 5a of the control circuit unit 51 also operates as the resonance characteristic setting unit. For this reason, the control circuit unit 51 includes a duty ratio setting circuit.

  Here, when the on-duty ratios of the respective switching elements of the inverter 1 are equal, the voltage of the capacitor C1 becomes zero, and all the high-frequency power of the inverter 1 is supplied to the resonance circuit unit 3, so that “A” in FIG. As shown, the output (lamp power) is maximized. On the other hand, when the on-period of the switching element Q11 is longer than that of the switching element Q12, or when the on-period of the switching element Q12 is larger than that of the switching element Q11, the capacitor C1 is set according to the difference between the two on-periods. DC power is stored. For this reason, a high frequency AC voltage corresponding to a voltage obtained by subtracting the voltage of the capacitor C1 from the voltage Vdc of the smoothing capacitor C2 is applied to the load resonance circuit unit including the discharge lamp FL and the resonance circuit unit 3. As the difference in the on period is larger, the output is further lowered as shown in FIG.

  Focusing on the characteristic of FIG. 5, the resonance characteristic setting means of the third embodiment sets the on-duty ratio of the starting control signal for controlling the on / off operation of each switching element of the inverter 1, The resonance characteristic of the resonance circuit unit 3 at the time of starting is configured to be the resonance characteristic B.

  Next, an operation that characterizes the third embodiment will be described. During preheating, by setting the on-duty of each switching element of the inverter 1 to 50%, the resonance characteristic of the resonance circuit unit 3 is set to the resonance characteristic A as in the first and second embodiments (FIG. 5, FIG. 5). (See FIG. 6). However, FIG. 6 is an operation explanatory diagram corresponding to the first embodiment.

  By setting the on-duty of the switching elements Q11 and Q12 of the inverter 1 to an unbalanced value at the time of starting and at the time of starting lighting, the resonance characteristic of the resonance circuit unit 3 is the resonance characteristic B as in the first and second embodiments. Set to After the start-up lighting, the resonance characteristic of the resonance circuit unit 3 is set to the resonance characteristic A as in the first and second embodiments by setting the on-duty of each switching element of the inverter 1 to 50%.

  That is, the resonance circuit unit 3 is set to the resonance characteristic A by setting the on-duty of each switching element of the inverter 1 to 50% during preheating and after starting lighting. The resonance characteristics B are set by setting the on-duty of one switching element Q11, Q12 to unbalanced values (for example, 10% and 90%, respectively).

  As described above, according to the third embodiment, as in the first and second embodiments, even if the discharge lamp has a high starting voltage without applying a gradually increasing pulse voltage to the discharge lamp FL at the start, Can be started and turned on, and the generation of flash noise after the start-up of the discharge lamp FL can be suppressed, and the user's discomfort due to the flash noise can be reduced.

  In addition, since the output voltage Vdc of the DC power supply 2 can always be constant, the configuration of the control circuit unit 52 for the DC power supply 2 is simplified, and the cost of the DC power supply 2 can be reduced.

  As a modification of the third embodiment, the resonance characteristic setting means sets both the output voltage of the DC power supply 2 and the on-duty of each switching element of the inverter 1, so that the resonance circuit unit 3 at the time of start-up etc. Even in the configuration in which the resonance characteristics are set, the same effect as in the third embodiment can be obtained.

(Embodiment 4)
FIG. 7 is a configuration diagram of a discharge lamp lighting device according to Embodiment 4 of the present invention, and FIGS. 8 and 9 are operation explanatory diagrams of the discharge lamp lighting device.

  As shown in FIG. 7, the discharge lamp lighting device of Embodiment 4 is different from Embodiments 1 and 2 between the positive output terminal and the negative output terminal of the DC power supply 2, as shown in FIG. 7. Are connected in series and the switching elements Q13 and Q14 are connected in series, and the inverter 1 is configured by a full bridge circuit, and the outputs of the inverter 1 and the resonance circuit unit 3 are controlled by phase shift control of the switching elements. The resonance circuit unit 3 has a resonance characteristic setting means for setting the resonance characteristic of the resonance circuit section 3 to the resonance characteristic B at the time of starting or the like.

  In FIG. 7, the DC power source 2 includes a filter circuit 21, a rectifier circuit 22 for full wave rectification, a chopper circuit 23 for power factor improvement, and a smoothing capacitor C <b> 2, and a constant voltage Vdc is applied to the inverter 1. DC power is supplied.

  The load circuit unit 3 includes an inductor L3 and a capacitor C3 connected in series between the connection point of the switching elements Q11 and Q12 and the connection point of the switching elements Q13 and Q14 via the capacitor C1 of the inverter 1. Both filaments of the discharge lamp FL are interposed on both ends of the capacitor C3.

  The resonance characteristic setting unit of the fourth embodiment is provided in the control circuit unit 51, and the inverter control function 5a of the control circuit unit 51 also operates as the resonance characteristic setting unit. The inverter control function 5a includes an oscillation control circuit 510, an oscillation circuit 511 such as an astable multivibrator that operates at a frequency set by the oscillation control circuit 510, and a complementary signal that generates complementary signals that are alternately turned on and off based on this output. A signal generation circuit 512, driver circuits 513 and 514 for outputting control signals for driving the switching elements Q11, Q12 and Q13 and Q14 based on the outputs of one and the other, respectively, and a phase shift circuit 515 as a resonance characteristic setting means It is comprised by.

  The resonance characteristic setting means sets the on-timing phase shift amount of the switching elements Q11 and Q14 and the on-timing phase shift amount of the switching elements Q12 and Q13, so that the resonance circuit section 3 at the time of starting and at the time of starting lighting is set. The resonance characteristic is set to the resonance characteristic B.

  Here, as shown in FIG. 8A, during preheating and after starting lighting, the phase shift amount by the resonance characteristic setting means becomes zero, and each switching element of the inverter 1 is the same as the conventional one by the inverter control function 5a. Turn on / off. Specifically, the switching element Q12 that is turned on / off complementarily with the switching element Q11 is turned on / off at the same timing as the switching element Q13, and the switching element Q14 that is turned on / off complementarily with the switching element Q13 is the switching element Q11. Turns on and off at the same timing as. If the duty ratio of the complementary signal generation circuit 512 is, for example, a constant 50%, each switching element of the inverter 1 is turned on / off at a duty ratio of 50%. In this case, when the switching elements Q11 and Q14 are turned on, a voltage at which the connection point side of the switching elements Q11 and Q12 is positive is applied to the load circuit unit 3 and the discharge lamp FL, and when the switching elements Q12 and Q13 are turned on, the switching element Q13 , Q14 is applied with a positive voltage to the load circuit unit 3 and the discharge lamp FL, and a high-frequency rectangular wave voltage of ± Vdc is applied to the load circuit unit 3 and the discharge lamp FL.

  On the other hand, at the time of starting and at the time of starting lighting, as shown in FIG. 8B, the phase shift amount is set to a predetermined amount by the resonance characteristic setting means. For example, if the ON timings of the switching elements Q11 and Q14 are phase shifted by a predetermined amount, the ON timings of the switching elements Q12 and Q13 are similarly phase shifted by a predetermined amount. When the phase is shifted by a predetermined amount as described above, a period in which the switching elements Q11 and Q13 are turned on is generated. In this period, the load circuit unit 3 and the discharge lamp FL are disconnected from the DC power source 2. 3 and the discharge lamp FL are not applied with a rectangular wave voltage. Similarly, a period in which the switching elements Q12 and Q14 are turned on occurs, and the rectangular wave voltage is not applied to the load circuit unit 3 and the discharge lamp FL during this period. Therefore, as shown in FIG. 9, the output to the discharge lamp FL increases as the phase shift amount increases, and the output to the discharge lamp FL decreases as the phase shift amount decreases.

  In other words, the inverter control function 5a outputs control signals for alternately turning on and off the switching elements Q11 and Q14 and the switching elements Q12 and Q13 as shown in FIG. While being output to the gate of the switching element, at the time of starting and at the time of starting lighting, in cooperation with the resonance characteristic setting means, as shown in FIG. 8B, the phase shift amount of the on-timing of the switching elements Q11 and Q14 and the switching element A control signal in which the phase shift amount at the on-timing of Q12 and Q13 is adjusted is output to the gates of these switching elements.

  As described above, according to the fourth embodiment, similarly to the first and second embodiments, even if the discharge lamp has a high starting voltage without applying a gradually increasing pulse voltage to the discharge lamp FL at the time of starting. Can be started and turned on, and the generation of flash noise after the start-up of the discharge lamp FL can be suppressed, and the user's discomfort due to the flash noise can be reduced.

Further, in the configuration including the inverter of the half bridge circuit configuration, if the on-duty ratio is shifted from 50%, the current (lamp current) I _FL flowing through the discharge lamp _FL is distorted as shown in FIG. Design for noise is required. On the other hand, according to the fourth embodiment, as shown in FIG. 8B, the waveform of the lamp current is not distorted by controlling the amplitude of the lamp current _{IFL by} the phase shift amount. Becomes easy.

(Embodiment 5)
11 and 12 are explanatory diagrams of the operation of the discharge lamp lighting device according to the fifth embodiment of the present invention.

The discharge lamp lighting device according to the fifth embodiment is configured, for example, in the same manner as the circuit of FIG. 3, and the frequency of the operating point of the inverter 1 and the resonance circuit unit 3 at the start of the discharge lamp FL, at the time of start lighting, and after the start lighting. the higher than no-load resonance frequency f ₀ and maintained at that no-load resonance frequency f ₀ frequency near, after starting lighting of the discharge lamp FL, the light output of the discharge lamp FL is adjusted by the dimming set by the optical unit 4 The discharge lamp FL is dimmed by adjusting the output voltage Vdc of the DC power supply 2 so that the light output level corresponds to the state.

At the time of preheating, as shown in FIG. 11, the resonance characteristic setting means sets the output voltage Vdc of the DC power supply 2 to a voltage of about 410 V, so that the resonance characteristic of the resonance circuit unit 3 is set to the resonance characteristic A. At this time, each switching element of the inverter 1 operates at the preheating operating frequency f _pre . At the time of starting and at the time of starting lighting, the resonance characteristic setting means sets the output voltage Vdc of the DC power supply 2 to a voltage of about 80 V, so that the resonance characteristic of the resonance circuit unit 3 is set to the resonance characteristic B. At this time, each switching element of the inverter 1 operates at the starting operating frequency f _str in the vicinity of the no-load resonance frequency f ₀ . The process up to this point is the same as in the second embodiment.

In the fifth embodiment, the start operation frequency f _{str in the} vicinity of the no-load resonance frequency f ₀ is maintained as the dimming operation frequency even after the start lighting, and when the discharge lamp FL is dimmed, the discharge lamp FL The output voltage Vdc of the DC power supply 2 is adjusted so that the optical output becomes an optical output level corresponding to the dimming state set by the dimmer 4.

Thus, the configuration in which the output voltage Vdc of the DC power supply 2 is adjusted for dimming is effective when lighting discharge lamps having different rated powers. For example, as shown in FIG. 12, when the rated powers of the discharge lamps FL1 and FL2 are different, the frequency of the operating point of the inverter 1 and the resonance circuit unit 3 is maintained at a frequency near the no-load resonance frequency f ₀ . The characteristic line of lamp voltage-lamp current is vertical. This is because, as shown in the following equation (1), the lamp current I _FL is regardless of the equivalent resistance of the discharge lamp, because is determined only by the output voltage Vdc of the inductor L3 and the DC power source 2. If the frequency of the operating point is not in the vicinity of the no-load resonance frequency f ₀ , the operating point is not perpendicular to the dotted characteristic line.

  Here, R is an equivalent resistance value of the discharge lamp, L is an inductance value of the inductor L3, and C is a capacitance value of the capacitor C3.

  As described above, according to the fifth embodiment, the same lamp current can be supplied with the same dimming signal to the discharge lamps having different rated powers. In particular, discharge lamps having substantially the same rated current can be lit in a dimming state that is substantially equal.

  As a modification of the fifth embodiment, after the start-up of the discharge lamp FL, the direct current power source is set so that the light output of the discharge lamp FL becomes the light output level corresponding to the dimming state set by the dimmer 4. The dimming of the discharge lamp FL may be performed by adjusting at least one of the output voltage Vdc of 2 and the on-duty of each switching element of the inverter 1.

(Embodiment 6)
FIG. 13 is a configuration diagram of a discharge lamp lighting device according to Embodiment 6 of the present invention.

  For example, as shown in FIG. 13, the discharge lamp lighting device according to the sixth embodiment is different from the first embodiment in that the DC power supply 2 has a constant output voltage, a current detection circuit unit 53, and a feedback control circuit unit 54. And a control circuit unit 51 configured to control only the switching elements of the inverter 1. Further, the discharge lamp FL is connected to the capacitor C3 through the capacitor C30 of the resonance circuit unit 3.

  The current detection circuit unit 53 detects a current (lamp current) flowing through the discharge lamp FL and outputs a lamp current signal as a detection signal.

  The feedback control circuit unit 54 includes an operational amplifier 541, resistors R541a to R541c, and a capacitor C541. The voltage signal of the reference voltage Vref that changes according to the dimming state set by the dimmer 4 and the lamp An error signal is output by amplifying an error from the current signal. In the example of FIG. 13, the lamp current signal is input to the inverting input terminal of the operational amplifier 541 via the resistor R541b, and the voltage signal of the reference voltage Vref is input to the non-inverting input terminal of the operational amplifier 541 via the resistor R541c. It is supposed to be. The gain of the operational amplifier 541 is determined by the proportional integral gain of the resistors R541a and R541b and the capacitor C541. Further, the capacitor C541 and the resistor R541a determine the cut-off frequency and reduce low-frequency ripple.

  The control circuit unit 51 of the sixth embodiment has an inverter control function 5a (not shown), and this inverter control function 5a is configured to operate also as a resonance characteristic setting means (not shown). In the sixth embodiment, for example, the resonance characteristics of the resonance circuit unit 3 are set by setting the on-duty of each switching element of the inverter 1.

  Further, the inverter control function 5a of the control circuit unit 51 determines the frequency of the operating point of the inverter 1 and the resonance circuit unit 3 and the ON state of each switching element of the inverter 1 according to the error signal output from the feedback control circuit unit 54. Adjust the discharge lamp FL by adjusting at least one of the duties. That is, when the output of the feedback control circuit unit 54 becomes negative and the lamp current exceeds the level of the dimming state set by the dimmer 4, the dimming is performed by increasing the frequency of the operating point. Dimming control is performed so that a lamp current corresponding to the level of the dimming state set by the optical device 4 flows. Further, when the output of the feedback control circuit unit 54 becomes positive and the lamp current is below the dimming level set by the dimmer 4, the dimming frequency is lowered by lowering the frequency of the operating point. Dimming control is performed so that a lamp current corresponding to the level of the dimming state set by the optical device 4 flows.

  As described above, according to the sixth embodiment, the same lamp current can be supplied with the same dimming signal to the discharge lamps having different rated powers. In particular, discharge lamps having substantially the same rated current can be lit in a dimming state that is substantially equal. In addition, since the operating frequency of the discharge lamp FL after starting lighting changes according to the dimming signal, preheating design and control power supply design using the characteristics can be performed.

  In the sixth embodiment, the current flowing through the discharge lamp FL is detected. However, any one of the current flowing through the discharge lamp FL, the power supplied to the discharge lamp FL, and the switching current of the switching element of the inverter 1 is used. It may be configured to detect one. Even with this configuration, the same effects as in the sixth embodiment can be obtained.

It is a block diagram of the discharge lamp lighting device of Embodiment 1 by this invention. It is operation | movement explanatory drawing of the discharge lamp lighting device. It is a block diagram of the discharge lamp lighting device of Embodiment 2 by this invention. It is a block diagram of the discharge lamp lighting device of Embodiment 3 by this invention. It is operation | movement explanatory drawing of the discharge lamp lighting device. It is operation | movement explanatory drawing of the discharge lamp lighting device. It is a block diagram of the discharge lamp lighting device of Embodiment 4 by this invention. It is operation | movement explanatory drawing of the discharge lamp lighting device. It is operation | movement explanatory drawing of the discharge lamp lighting device. It is explanatory drawing of the effect of the discharge lamp lighting device. It is operation | movement explanatory drawing of the discharge lamp lighting device of Embodiment 5 by this invention. It is operation | movement explanatory drawing of the discharge lamp lighting device. It is a block diagram of the discharge lamp lighting device of Embodiment 6 by this invention. It is operation | movement explanatory drawing of the conventional discharge lamp lighting device when the starting voltage of the discharge lamp with which a discharge lamp lighting device is mounted | worn is low. It is operation | movement explanatory drawing of the conventional discharge lamp lighting device when the starting voltage of the discharge lamp with which a discharge lamp lighting device is mounted | worn is high.

Explanation of symbols

FL discharge lamp 1 inverter 2 DC power supply 3 resonance circuit section 4 dimmer 5 control circuit section 5a inverter control function 5b DC power supply output control function

Claims (8)

An inverter constituted by a switching element, a DC power source for supplying DC power to the inverter, and an output of the inverter together with a discharge lamp, each having no load resonance characteristics when the discharge lamp is turned off or on. Or, it has a resonance characteristic that automatically changes to a load resonance characteristic, and in conjunction with the ON / OFF operation of the switching element of the inverter, the DC power from the DC power source is converted into a high frequency power, and the high frequency power is converted into the discharge lamp. A discharge lamp lighting device comprising a resonance circuit section to be supplied to
A dimming setting means for setting a dimming state of the discharge lamp;
At the time of starting the discharge lamp, the Q value of the resonance characteristic of the resonance circuit unit becomes larger than the Q value of the resonance characteristic of the resonance circuit unit at the rated lighting of the discharge lamp, and the inverter and the resonance circuit unit The frequency of the operating point of the discharge lamp is higher than the no-load resonance frequency due to the no-load resonance characteristic, and is a frequency in the vicinity of the no-load resonance frequency and at least a frequency corresponding to the starting voltage of the discharge lamp. At the time of lighting, the frequency of the operating point of the inverter and the resonance circuit unit matches the frequency of the operating point corresponding to the light output level at the dimming lower limit of the discharge lamp. A discharge lamp lighting device comprising: resonance characteristic setting means for setting resonance characteristics. An inverter constituted by a switching element, a DC power source for supplying DC power to the inverter, and an output of the inverter together with a discharge lamp, each having no load resonance characteristics when the discharge lamp is turned off or on. Or, it has a resonance characteristic that automatically changes to a load resonance characteristic, and in conjunction with the ON / OFF operation of the switching element of the inverter, the DC power from the DC power source is converted into a high frequency power, and the high frequency power is converted into the discharge lamp. A discharge lamp lighting device comprising a resonance circuit section to be supplied to
A dimming setting means for setting a dimming state of the discharge lamp;
At the time of starting the discharge lamp, the Q value of the resonance characteristic of the resonance circuit unit becomes larger than the Q value of the resonance characteristic of the resonance circuit unit at the rated lighting of the discharge lamp, and the inverter and the resonance circuit unit The frequency of the operating point of the discharge lamp is higher than the no-load resonance frequency due to the no-load resonance characteristic, and is a frequency in the vicinity of the no-load resonance frequency and at least a frequency corresponding to the starting voltage of the discharge lamp. At the time of lighting, the frequency of the operating point of the inverter and the resonance circuit unit is set to the frequency of the operating point corresponding to the light output level in the dimming state set by the dimming setting means or higher than that. And a resonance characteristic setting means for setting a resonance characteristic of the resonance circuit unit at the time of starting.   The resonance characteristic setting means sets the resonance characteristic of the resonance circuit unit at the time of starting by setting at least one of an output voltage of the DC power supply and an on-duty of a switching element of the inverter. The discharge lamp lighting device according to claim 1 or 2.   When starting the discharge lamp, the frequency of the operating point of the inverter and the resonant circuit unit is swept from the preheating operating frequency side higher than the no-load resonant frequency to the no-load resonant frequency side of the inverter. 4. The discharge lamp lighting device according to claim 1, wherein a starting control signal for controlling on / off operation of the switching element is output to the switching element. The inverter is constituted by a half-bridge circuit that connects the switching elements in series between both output terminals of the DC power source,
The resonance characteristic setting means sets an on-duty ratio of a start control signal for controlling the on / off operation of each switching element of the half bridge circuit, thereby setting the resonance characteristic of the resonance circuit unit at the time of starting. It sets. The discharge lamp lighting device in any one of Claim 1 to 4 characterized by the above-mentioned. The inverter has a first switching element and a second switching element connected in series as the switching element between a positive output terminal and a negative output terminal of the DC power supply, respectively, and a third switching element and a fourth switching element. Are configured by a full bridge circuit that connects each in series,
The resonance characteristic setting means sets an on-timing phase shift amount of the first switching element and the fourth switching element and an on-timing phase shift amount of the second switching element and the third switching element. The discharge lamp lighting device according to claim 1, wherein a resonance characteristic of the resonance circuit unit at the time of starting is set. The frequency of the operating point of the inverter and the resonance circuit unit at the time of starting the discharge lamp, at the time of starting lighting and after the starting lighting is maintained at a frequency higher than the no-load resonance frequency and in the vicinity of the no-load resonance frequency,
After the start-up of the discharge lamp, the output voltage of the DC power source and the switching of the inverter are set so that the light output of the discharge lamp becomes a light output level corresponding to the dimming state set by the dimming setting means. 3. The discharge lamp lighting device according to claim 1, wherein the discharge lamp is dimmed by adjusting at least one of the on-duty of the element. Detecting means for detecting any one of a current flowing through the discharge lamp, electric power supplied to the discharge lamp and a switching current of the switching element and outputting a detection signal; and a dimming set by the dimming setting means An error amplifying means for amplifying an error between a signal that changes according to the light state and the detection signal and outputting an error signal;
Dimming the discharge lamp by adjusting at least one of the operating point frequency of the inverter and the resonance circuit unit and the on-duty of the switching element of the inverter according to the error signal output by the error amplification means The discharge lamp lighting device according to claim 1 or 2, characterized in that:

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