JP2012113878A - Lighting device and luminaire using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device which can suppress a rise of its temperature and keep lighting, even where it is used with a plurality of power sources whose power source voltages are different from each other, and provide a luminaire using the lighting device.SOLUTION: A lighting device comprises: a first converter unit 2 for converting voltage from an input power source AC1 into DC voltage and outputting an input voltage V1; a second converter unit 3 for converting the voltage outputted from the first converter unit 2 into a voltage required for lighting a high-pressure discharge lamp 100 and supplying it to the high-pressure discharge lamp 100; and a control unit 4. The control unit 4 includes a first setting portion 45 for setting a target value of the input voltage V1 in a not-lighting moment, a second setting portion 46 for setting a target value of the input voltage V1 in a stably-lighting moment, and a third setting portion 47 for setting a target value of the input voltage V1 in a certain period after a start-up, and controls the input voltage V1 based on target values set in the respective setting portions. The target values set in the respective setting portions are set smaller in order of the first setting portion 45, the third setting portion 47, and the second setting portion 46.

Description

  The present invention relates to a lighting device for lighting a light source such as a high-pressure discharge lamp and a lighting fixture using the same.

  Conventionally, high-pressure discharge lamps have been widely used as high-intensity, high-power illumination, but a ballast (lighting device) is required to stably light up a high-pressure discharge lamp that is a type of discharge lamp. Become. As a lighting device for a high-pressure discharge lamp, there are mainly a copper-iron type ballast in which a copper wire is wound around an iron core and an electronic ballast using a semiconductor switching element. In recent years, electronic ballasts have become widespread from the viewpoint of energy saving, and miniaturization and cost reduction are achieved year by year. And with the miniaturization of the lighting device, the heat dissipating capability of the lighting device is lowered, and the lighting device is getting high temperature.

  Here, the lighting device may be used in combination with a plurality of power supplies (for example, a 100V power supply and a 200V power supply) having different power supply voltages. The lighting device incorporates a boost converter circuit that boosts the power supply voltage, and this boost converter circuit is usually designed according to the power supply having the higher power supply voltage. For this reason, when the lighting device is used for a power source having a lower power supply voltage, the boost ratio of the boost converter circuit is larger than that used for a power source having a higher power supply voltage, resulting in a larger circuit loss and a further lighting device. However, there was a problem that the temperature became high.

  As a solution to the above problem, the boosted voltage of the boost converter circuit at the time of input of the power supply voltage of 100V is reduced from the boosted voltage at the time of input of the power supply voltage of 200V at the time of load (when the discharge lamp is turned on) A constructed discharge lamp lighting device is disclosed in Patent Document 1.

Japanese Patent No. 3850052

  By the way, considering that the light source is a high-pressure discharge lamp and the high-pressure discharge lamp is stably lit as described above, the higher the output voltage of the boost converter circuit, the more stable the lighting. However, when the output voltage of the boost converter circuit is varied according to the power supply voltage as in the conventional example described in Patent Document 1, a difference occurs in the ability to maintain the discharge lamp depending on the magnitude of the power supply voltage. . For example, it is assumed that a light source such as a high-pressure discharge lamp at the end of life is likely to be unstable. When the same light source is turned on in two areas where different power supply voltages are distributed, the high-pressure discharge lamp does not flicker in one area, but the high-pressure discharge lamp flickers in the other area. There was a risk of it occurring. Further, the high pressure discharge lamp requires several minutes from the start until the lighting state is stabilized, and this period is very unstable. During this period, if the output voltage of the boost converter circuit fluctuates as in the conventional example described in Patent Document 1, the started high-pressure discharge lamp may be extinguished and the lighting may not be maintained.

  As a general countermeasure against the above problems, the output voltage of the boost converter circuit is not changed from the voltage at non-lighting (no load) for a certain period of time after the high-pressure discharge lamp starts, and is output after a certain period of time has elapsed. A method is conceivable in which the voltage is set to a lower voltage than when the lamp is not lit. However, in this method, since the period during which a high voltage is output becomes long, a large stress is applied to circuit components such as switching elements and capacitors, and the circuit loss of the boost converter circuit increases, resulting in a high temperature of the lighting device. There was a problem of becoming.

  The present invention has been made in view of the above points, and even when used for a plurality of power supplies having different power supply voltages, a lighting device capable of suppressing an increase in the temperature of the device and maintaining lighting can be provided. It aims at providing the used lighting fixture.

  The lighting device of the present invention converts a voltage from an input power source into a predetermined DC voltage and outputs the voltage, and converts the output voltage of the first converter into a voltage required for lighting the light source. A second converter unit that supplies the light source, and a control unit that controls the first converter unit and the second converter unit, and the control unit includes the first converter unit when the light source is not lit. A first setting unit that sets a target value of the output voltage of the converter unit, a second setting unit that sets a target value of the output voltage of the first converter unit when the light source is stably lit, and the light source And a third setting unit for setting a target value of the output voltage of the first converter unit in a certain period after starting, and the first converter based on the target value set by each setting unit Control the output voltage of the unit, Target value set by the setting unit, the first setting portion, the third setting unit, characterized by comprising reduced in the order of the second setting unit.

  In the lighting device, it is preferable that the third setting unit decreases the target value with a constant inclination as time elapses.

  In this lighting device, it is preferable that the third setting unit decreases the target value stepwise as time passes.

  The lighting device includes a lamp voltage detection unit that detects a lamp voltage applied to the light source, and the third setting unit decreases a target value based on the lamp voltage detected by the lamp voltage detection unit. It is preferable.

  In this lighting device, the second converter unit converts the output voltage of the first converter unit into a rectangular wave and outputs the rectangular wave, and the control unit is in a certain period after starting the light source. A fourth setting unit that sets a target value of the output voltage of the first converter unit and a target value to be set is smaller than a target value set by the third setting unit; The output voltage of the first converter unit is controlled on the basis of a target value set by the third setting unit when the rectangular wave is inverted during a later fixed period. It is preferable to control the output voltage of the first converter unit based on the target value set in (1).

  The lighting device may include a power supply voltage detection unit that detects a power supply voltage of the input power supply, and the second setting unit may change a target value based on the power supply voltage detected by the power supply voltage detection unit. preferable.

  The lighting fixture of the present invention includes any one of the lighting devices described above, and a fixture main body that holds the lighting device and the light source.

  The present invention has an effect that even when used for a plurality of power supplies having different power supply voltages, it is possible to suppress an increase in the temperature of the apparatus and to maintain lighting.

It is a circuit diagram which shows Embodiment 1 of the lighting device which concerns on this invention. It is a wave form diagram for demonstrating the operation | movement same as the above. It is a figure which shows Embodiment 2 of the lighting device which concerns on this invention, (a) is a wave form diagram for demonstrating operation | movement, (b), (c) is a wave form diagram for demonstrating another operation | movement. It is a figure which shows Embodiment 3 of the lighting device which concerns on this invention, (a) is a wave form diagram for demonstrating operation | movement, (b) is a correlation diagram of a 3rd reference voltage and lamp voltage. It is a wave form chart for explaining other operations same as the above. It is a figure which shows Embodiment 4 of the lighting device which concerns on this invention, (a) is a circuit diagram, (b) is a wave form diagram for demonstrating operation | movement. It is a figure which shows Embodiment 5 of the lighting device which concerns on this invention, (a) is a circuit diagram, (b) is a wave form diagram for demonstrating operation | movement. (A)-(c) is the schematic which shows embodiment of the lighting fixture which concerns on this invention.

(Embodiment 1)
Hereinafter, Embodiment 1 of the lighting device according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the present embodiment includes a rectifying unit 1, a first converter unit 2, a second converter unit 3, and a control unit 4. The rectifying unit 1 is composed of a diode bridge, and full-wave rectifies an AC voltage supplied from an AC power source AC1 (input power source; in this embodiment, 100 V power source) and outputs the rectified voltage to the first converter unit 2 at the subsequent stage.

  The first converter unit 2 is a so-called step-up chopper circuit having a switching element Q1 made of, for example, an FET, a choke coil CH1, a diode D1, and a smoothing capacitor C1. The first converter unit 2 improves the power factor by boosting the pulsating voltage output from the rectifying unit 1 to a desired DC voltage and outputting it. Since the step-up chopper circuit is conventionally known, detailed description thereof is omitted here.

  The second converter unit 3 is a so-called step-down chopper circuit having four switching elements Q2 to Q5 made of, for example, FETs, a choke coil CH2, and a capacitor C3. In the second converter unit 3, a series circuit of two switching elements Q2 and Q3 and a series circuit of the remaining two switching elements Q4 and Q5 are connected in parallel between the output terminals of the first converter unit 2. Yes. A series circuit of a choke coil CH2 and a capacitor C3 is connected between the connection point of the switching elements Q2, Q3 and the connection point of the switching elements Q4, Q5. Further, a series circuit of the resonance circuit 30 and the high-pressure discharge lamp 100 (light source) is connected in parallel with the capacitor C3. The resonant circuit 30 includes a pulse transformer PT1 connected in series to the high-pressure discharge lamp 100, and a capacitor C2 inserted between the tap of the pulse transformer PT1 and the output terminal on the low potential side of the first converter unit 2. is doing.

  The control unit 4 includes an input voltage detection unit 40 that detects an output voltage of the first converter unit 2, that is, an input voltage (a voltage across the smoothing capacitor C1) V1 to the second converter unit 3. In addition, the control unit 4 includes a first drive control unit 41 that performs switching control of the switching element Q1 of the first converter unit 2 so that the detected input voltage V1 becomes a desired voltage level.

  Further, the control unit 4 detects the output voltage of the second converter unit 3, that is, the lamp voltage V2 applied to the high pressure discharge lamp 100, and the high voltage based on the detected lamp voltage V2. A lighting determination unit 44 that determines whether the discharge lamp 100 is turned on or off. Furthermore, the control unit 4 includes a second drive control unit 43 that performs switching control of the switching elements Q2 to Q5 of the second converter unit 3 so that the detected lamp voltage V2 becomes a desired voltage level.

  The second drive control unit 43 receives the determination result from the lighting determination unit 44, and switches the switching unit 43B that switches the operation mode of the second converter unit 3, and the switching elements Q4 and Q5 according to the detected lamp voltage V2. And a calculation unit 43A that determines the drive frequency and the ON period. The switching unit 43B includes a start mode for outputting a high voltage for starting the high pressure discharge lamp 100 from the second converter unit 3, and a voltage for stably lighting the high pressure discharge lamp 100 from the second converter unit 3. Switch to stable lighting mode to output. The calculation unit 43A controls the switching elements Q4 and Q5 via the switching unit 43B in the stable lighting mode.

  For example, in the stable lighting mode, as shown in FIG. 2, the second drive control unit 43 of the control unit 4 turns on / off the switching elements Q2, Q5, and turns on / off the switching elements Q3, Q4. The period to be used is alternated at a predetermined frequency (several hundred Hz). Here, in the former period, the switching elements Q3 and Q4 are in an off state, and in the latter period, the switching elements Q2 and Q5 are in an off state. In the former period, the second drive control unit 43 turns on / off the switching element Q5 at a predetermined frequency (about several tens of kHz) with the switching element Q2 turned on. In the latter period, the second drive control unit 43 turns on / off the switching element Q4 at a predetermined frequency (about several tens of kHz) while the switching element Q3 is turned on.

  Here, the control unit 4 sets the first setting unit 45 that sets the target value of the input voltage V1 when the high-pressure discharge lamp 100 is not lit, and the target value of the input voltage V1 when the high-pressure discharge lamp 100 is stably lit. And a second setting unit 46 for setting. Furthermore, the control unit 4 includes a third setting unit 47 that sets a target value of the input voltage V1 at a certain time TS1 after the high-pressure discharge lamp 100 is started.

  In the first setting unit 45, as shown in FIG. 2, the target value is set so that the input voltage V1 at the time of non-lighting becomes the first reference voltage VB1. In the second setting unit 46, as shown in FIG. 2, the target value is set so that the input voltage V1 at the time of lighting becomes the second reference voltage VB2. In the third setting unit 47, the target value is set so that the input voltage V1 at the fixed time TS1 after the start becomes the third reference voltage VB3. At this time. The target values of the setting units 45 to 47 are set so that the reference voltages VB1, VB3, and VB2 during non-lighting, starting process, and stable lighting satisfy VB1> VB3> VB2. The fixed time TS1 is, for example, 1 minute to several minutes, which is a stable time defined by the high-pressure discharge lamp 100. Then, the first drive control unit 41 appropriately reads out the target value from each of the setting units 45 to 47, and sets the first converter unit 2 so that the input voltage V1 becomes the reference voltages VB1 to VB3 based on the target value. Control.

  That is, as shown in FIG. 2, the input voltage V1 is controlled to be the first reference voltage VB1 at the time of non-lighting until the high pressure discharge lamp 100 breaks down, and a certain time TS1 after the high pressure discharge lamp 100 is started. Then, the input voltage V1 is controlled to be the third reference voltage VB3. Further, when the high pressure discharge lamp 100 is stably lit after a certain time TS1 has elapsed since the high pressure discharge lamp 100 was started, the input voltage V1 is controlled to be the second reference voltage VB2.

  Hereinafter, the operation of the present embodiment will be described with reference to FIG. FIG. 2 shows a waveform diagram of each part of the high pressure discharge lamp 100 from a non-lighting state to a stable lighting state. First, when a lighting switch (not shown) is turned on when the high pressure discharge lamp 100 is in a non-lighting state and the power is turned on, the first drive control unit 41 of the control unit 4 starts the control operation, and the switching element Q1 is set to several. Switching control to turn on / off at about 10 kHz is performed. As a result, the first converter unit 2 outputs a DC voltage (input voltage V1) obtained by boosting the power supply voltage both when the high-pressure discharge lamp 100 is not lit and when it is lit. Here, the first converter unit 2 suppresses the input current distortion by increasing the input power factor.

  When the input voltage V1 reaches a predetermined voltage value, the second drive control unit 43 of the control unit 4 starts operation. At this time, the high-pressure discharge lamp 100 is not yet lit, and its equivalent impedance is a high impedance close to infinity. The switching unit 43B is in the start mode. The second drive control unit 43 alternates a period during which the switching elements Q2, Q5 are on and a period during which the switching elements Q3, Q4 are on at a predetermined frequency f0 (about several hundred kHz). Here, the predetermined frequency f0 is a frequency close to the resonance frequency of the resonance circuit 30, and a sine wave-like high voltage is generated in the primary winding N1 of the pulse transformer PT1. The sinusoidal high voltage generated in the primary winding N1 is boosted by the turn ratio of the primary winding N1 and the secondary winding N2, and the boosted voltage is applied to the high pressure discharge lamp 100 via the capacitor C3. The As a result, the high pressure discharge lamp 100 is broken down and started. At this time, since the high-pressure discharge lamp 100 has a low impedance that is close to a short circuit, the voltage across the high-pressure discharge lamp 100 decreases to approximately 0V.

  On the other hand, the lighting determination unit 44 determines whether the high-pressure discharge lamp 100 is lit or not based on whether or not the lamp voltage V2 detected by the lamp voltage detection unit 42 exceeds a predetermined threshold. That is, when the lamp voltage V2 exceeds the predetermined threshold, the lighting determination unit 44 determines that the high-pressure discharge lamp 100 is in a non-lighting state, and the output voltage becomes a high level. On the other hand, when the lamp voltage is lower than the predetermined threshold, the lighting determination unit 44 determines that the high-pressure discharge lamp 100 is in a lighting state, and the output voltage becomes a low level.

  Here, when the high-pressure discharge lamp 100 is started, the lamp voltage V2 is reduced to substantially 0V as described above, and thus falls below a predetermined threshold value. Therefore, the lighting determination unit 44 determines that the high-pressure discharge lamp 100 is lit, The output voltage becomes low level and is input to the switching unit 43B. Upon receiving this low level voltage signal, the switching unit 43B switches the operation mode from the start mode to the stable lighting mode.

  In the stable lighting mode, as already described above, the second drive control unit 43 determines a period during which the switching elements Q2, Q5 are turned on / off and a period during which the switching elements Q3, Q4 are turned on / off. Are alternated at a frequency f1 (approximately several hundred Hz). Therefore, a rectangular wave AC voltage having a frequency f1 is applied to the high-pressure discharge lamp 100. The high-pressure discharge lamp 100 has a low voltage at both ends (lamp voltage V2) immediately after starting, but the lamp voltage V2 increases to reach the rated voltage as the inside of the lamp becomes high temperature and high pressure, and a stable lighting state is obtained. Note that the calculation unit 43A appropriately controls the drive frequency and on-period of the switching elements Q4 and Q5 based on the input lamp voltage V2. For this reason, appropriate electric power is supplied to the high pressure discharge lamp 100, and the stable lighting state is maintained.

  Here, in this embodiment, since a large amount of energy is required to start the high-pressure discharge lamp 100 when not lit, the first reference voltage VB1 is set to a high voltage (400 V in this embodiment). is doing. In addition, in a certain time TS1 after starting, that is, in the starting process, even when the lighting state of the high pressure discharge lamp 100 becomes unstable, the high voltage discharge lamp 100 is set to a voltage (350 V in this embodiment) that does not go out. 3 reference voltage VB3 is set. When starting the high pressure discharge lamp 100, the temperature of the high pressure discharge lamp 100 itself is low, so that the lamp current does not flow when the polarity of the rectangular AC voltage applied to the high pressure discharge lamp 100 is reversed. There is a risk of becoming. Therefore, if the input voltage V1 is sufficiently high when the high pressure discharge lamp 100 is started, the lamp voltage V2 can be quickly increased to a voltage necessary for re-ignition, and the unstable lighting state as described above can be eliminated. Is possible.

  Furthermore, at the time of stable lighting of the high-pressure discharge lamp 100, the second reference voltage VB2 is set to the minimum voltage (170 V in the present embodiment) necessary for stably lighting the high-pressure discharge lamp 100. . Thereby, the voltage applied to the high pressure discharge lamp 100 at the time of stable lighting can be suppressed as much as possible.

  As described above, in the present embodiment, the output voltage of the first converter unit 2, that is, the input voltage V <b> 1 is the reference voltages VB <b> 1 and VB <b> 3 when the high-pressure discharge lamp 100 is not lit, during the starting process, and during stable lighting. , VB2, target values are set by the setting units 45 to 47. For this reason, even in an unstable lighting state after the high-pressure discharge lamp 100 is started, the high-pressure discharge lamp 100 can be shifted to a stable lighting state without being turned off. In addition, since the first converter unit 2 does not output a voltage higher than necessary during a certain period during the starting process, a higher voltage than the general countermeasure described in the problem to be solved by the invention is obtained. The output period can be shortened. Therefore, stress and circuit loss applied to the circuit components of the device can be reduced, and as a result, the temperature of the device can be prevented from being increased.

  Furthermore, since the target value is set so that the input voltage V1 becomes the second reference voltage VB2 when the high-pressure discharge lamp 100 is stably lit, it is applied to the high-pressure discharge lamp 100 when the high-pressure discharge lamp 100 is steadily lit. The voltage can be suppressed as much as possible. For this reason, even when used for a plurality of power supplies having different power supply voltages, the stress and circuit loss applied to the circuit components of the apparatus can be reduced to prevent the apparatus from becoming hot.

(Embodiment 2)
Hereinafter, Embodiment 2 of the lighting device according to the present invention will be described with reference to the drawings. However, since the basic configuration of the present embodiment is common to that of the first embodiment, common portions are denoted by the same reference numerals and description thereof is omitted. In the present embodiment, as shown in FIG. 3A, the third setting unit 47 decreases the target value with a constant slope as time elapses, that is, the third reference voltage VB3 is constant. It is characterized by decreasing with inclination.

  As described in the first embodiment, since the lighting state may become unstable when the high pressure discharge lamp 100 is started, it is unstable when the input voltage V1 is sufficiently high when the high pressure discharge lamp 100 is started. The lighting state can be eliminated. Here, after the high-pressure discharge lamp 100 is turned on, the lamp temperature gradually increases with the passage of time, and the lighting state is stabilized. Therefore, in the present embodiment, the third reference voltage VB3 is set to a large value at the initial start of the high-pressure discharge lamp 100 whose lighting state is more unstable, and the third reference voltage VB3 with a constant slope as time elapses. Is reduced.

  As described above, in the present embodiment, a high voltage is applied to the high pressure discharge lamp 100 so that the high pressure discharge lamp 100 does not go out during the starting process of the high pressure discharge lamp 100. For this reason, even in an unstable lighting state after the high-pressure discharge lamp 100 is started, the high-pressure discharge lamp 100 can be shifted to a stable lighting state without being turned off. Further, by lowering the third reference voltage V3 as the lighting state of the high-pressure discharge lamp 100 becomes stable, it is possible to further reduce the stress and circuit loss applied to the circuit components of the device, resulting in a higher temperature of the device. Can be prevented more effectively.

  Note that the third setting unit 47 may set the target value so as to decrease the third reference voltage VB3 in a curve as time passes, as shown in FIG. Further, as shown in FIG. 3C, the third setting unit 47 may set the target value so as to decrease the third reference voltage VB3 step by step with time. In any case, the same effects as in the present embodiment can be obtained.

(Embodiment 3)
Hereinafter, Embodiment 3 of the lighting device according to the present invention will be described with reference to the drawings. However, since the basic configuration of the present embodiment is common to that of the first embodiment, common portions are denoted by the same reference numerals and description thereof is omitted. In the present embodiment, as shown in FIGS. 4A and 4B, the third setting unit 47 decreases the target value based on the lamp voltage V2 detected by the lamp voltage detection unit 42, that is, 3 is characterized by decreasing the reference voltage VB3.

  In the first embodiment, the fixed time TS1 after the start of the high-pressure discharge lamp 100 is set as the starting process period. However, in this embodiment, the lamp voltage V2 is set to a predetermined value (for example, the rated lamp voltage) after the high-pressure discharge lamp 100 is started. The period until the starting time is 90% or more of VT1. And as shown in FIG.4 (b), the target value is set by the 3rd setting part 47 so that the 3rd reference voltage VB3 may be reduced with the raise of the lamp voltage V2. Here, when the lamp voltage V2 rises to the vicinity of the lamp rated voltage VT1, the high-pressure discharge lamp 100 enters a relatively stable lighting state, so the third reference voltage VB3 is set to a low voltage (175 V in this embodiment). is doing.

  When the lamp voltage V2 becomes equal to or higher than a predetermined value, it is determined that the high pressure discharge lamp 100 has shifted to a stable lighting state. Then, the first drive control unit 41 reads the target value from the second setting unit 46, and controls the first converter unit 2 so that the input voltage V1 becomes the second reference voltage VB2 based on the target value. .

  As shown in FIG. 5, the period from the start of the high-pressure discharge lamp 100 until the lamp current becomes a predetermined value (for example, 110% of the lamp rated current) or less is set as the starting process period, and the lamp current decreases. Then, the third setting unit 47 may decrease the target value.

  As described above, in the present embodiment, the target value is set by the third setting unit 47 so as to lower the third reference voltage VB3 based on the electrical characteristics such as the lamp rated voltage and the lamp rated current of the high-pressure discharge lamp 100. It is set. Therefore, even if there is a variation in characteristics until the high pressure discharge lamp 100 reaches a stable lighting state due to the type of the high pressure discharge lamp 100 or deterioration over time, the input voltage V1 is set to an appropriate value, and the high pressure discharge lamp 100 is It is possible to shift to a stable lighting state without turning off. Further, as in the second embodiment, the third reference voltage V3 is lowered as the lighting state of the high-pressure discharge lamp 100 becomes stable, so that the stress and circuit loss applied to the circuit components of the apparatus can be further reduced. As a result, it is possible to more effectively prevent the temperature of the apparatus from increasing.

(Embodiment 4)
Hereinafter, Embodiment 4 of the lighting device according to the present invention will be described with reference to the drawings. However, since the basic configuration of the present embodiment is common to that of the first embodiment, common portions are denoted by the same reference numerals and description thereof is omitted. In the present embodiment, as shown in FIG. 6A, the control unit 4 sets the target value of the input voltage V1 for a certain period after starting the high-pressure discharge lamp 100, that is, during the starting process. It is characterized by having a portion 48.

  As shown in FIG. 6A, the fourth setting unit 48 has a fourth reference voltage VB4 (170 V in the present embodiment) in which the input voltage V1 during the starting process is lower than the third reference voltage VB3. Set the target value so that Then, the first drive control unit 41 controls the first converter unit 2 so as to vary the input voltage V1 based on the polarity inversion signal from the switching unit 43B. The polarity inversion signal is a signal that informs the timing at which the polarity of the lamp voltage V2 is inverted.

  As described in the first embodiment, when the high-pressure discharge lamp 100 is started, the temperature of the high-pressure discharge lamp 100 itself is low. Therefore, the lamp current is particularly generated when the polarity of the rectangular AC voltage applied to the high-pressure discharge lamp 100 is reversed. Disappears instantaneously and disappears easily. Therefore, in the present embodiment, the first drive control unit 41 reads out and inputs the target value from the third setting unit 47 during a predetermined time (for example, 500 μs) before and after the inversion of the lamp voltage V2 during the starting process. Control is performed so that the voltage V1 becomes the third reference voltage VB3. In a period other than the predetermined time during the starting process, the first drive control unit 41 reads the target value from the fourth setting unit 48 and controls the input voltage V1 to be the fourth reference voltage VB4. ing.

  As described above, in the present embodiment, a high voltage that does not cause the high-pressure discharge lamp 100 to turn off is applied to the high-pressure discharge lamp 100 only when the lamp voltage V <b> 2 that is particularly likely to turn off during the starting process of the high-pressure discharge lamp 100 is reversed. Applied. For this reason, even in an unstable lighting state after the high-pressure discharge lamp 100 is started, the high-pressure discharge lamp 100 can be shifted to a stable lighting state without being turned off. Further, during the starting process, during a period other than when the lamp voltage V2 is reversed, a minimum voltage necessary for stably lighting the high-pressure discharge lamp 100 is applied to the high-pressure discharge lamp 100. For this reason, the stress and circuit loss which are given to the circuit components of the apparatus can be further reduced, and as a result, the high temperature of the apparatus can be more effectively prevented.

  Note that, as in the second embodiment, the third reference voltage V3 may be decreased with time, that is, as the lighting state of the high-pressure discharge lamp 100 becomes stable. Further, in the present embodiment, as in the third embodiment, the starting process period is from when the high-pressure discharge lamp 100 is started until the lamp voltage V2 becomes equal to or higher than a predetermined value (for example, 90% of the lamp rated voltage VT1). Yes. Of course, the period from the start of the high-pressure discharge lamp 100 until the lamp current becomes a predetermined value (for example, 110% of the rated lamp current) or less is set as the period of the starting process, and the third setting unit 47 as the lamp current decreases. May decrease the target value.

(Embodiment 5)
Hereinafter, Embodiment 5 of the lighting device according to the present invention will be described with reference to the drawings. However, since the basic configuration of the present embodiment is common to that of the fourth embodiment, common portions are denoted by the same reference numerals and description thereof is omitted. In the present embodiment, as shown in FIG. 7A, the control unit 4 includes a power supply voltage detection unit 49 that detects the power supply voltage of the input power supply AC1, and the second setting unit 46 and the fourth setting unit 48 are provided. The target value is changed based on the power supply voltage detected by the power supply voltage detection unit 49.

  As described in the background art, the step-up chopper circuit such as the first converter unit 2 is usually designed in accordance with the power supply having the higher power supply voltage. For this reason, when the device is used for a power source having a lower power supply voltage, the step-up ratio of the first converter unit 2 is larger than that for a power source having a higher power supply voltage, and the circuit loss is increased.

  Therefore, in this embodiment, as shown in FIG. 7B, when the power supply voltage is lower (100 V in this embodiment), the second reference voltage VB2 and the fourth reference voltage VB4 are used. The target values of the second setting unit 46 and the fourth setting unit 48 are set so that becomes 170V. When the power supply voltage is higher (200 V in this embodiment), as shown in FIG. 7B, the second reference voltage VB2 and the fourth reference voltage VB4 are set to 340V. The target values of the second setting unit 46 and the fourth setting unit 48 are set. For this reason, even when the apparatus is used for a power supply having a lower power supply voltage, the step-up ratio of the first converter unit 2 does not increase.

  As described above, in this embodiment, since the input voltage V1 at the time of stable lighting of the high-pressure discharge lamp 100 is changed based on the power supply voltage, the stress or circuit applied to the circuit components of the apparatus as compared with the fourth embodiment. Loss can be further reduced, and high temperature of the apparatus can be more effectively prevented. Of course, as in the fourth embodiment, when the lamp voltage V2 is reversed during the starting process of the high-pressure discharge lamp 100, a high voltage that does not cause the high-pressure discharge lamp 100 to turn off is applied to the high-pressure discharge lamp 100. For this reason, even in an unstable lighting state after the high-pressure discharge lamp 100 is started, the high-pressure discharge lamp 100 can be shifted to a stable lighting state without being turned off.

  In the present embodiment, the target values of the second setting unit 46 and the fourth setting unit 48 are changed based on the power supply voltage. However, only the target value of the second setting unit 46 is changed based on the power supply voltage. It may be changed. Even in this case, the stress and circuit loss applied to the circuit components of the apparatus can be further reduced as compared with the fourth embodiment, and the temperature of the apparatus can be prevented more effectively.

  Hereinafter, embodiments of a lighting apparatus according to the present invention will be described with reference to the drawings. The lighting fixtures shown in FIGS. 8A to 8C are all the lighting device A1 according to any of the first to fifth embodiments, the fixture main body 200 in which a lamp socket (not shown) is housed, and the lighting device. A power cable 201 for connecting A1 and the lamp socket is provided in common. Then, lighting power is supplied from the lighting device A1 to the high-pressure discharge lamp (not shown) attached to the lamp socket via the power cable 201.

  These lighting fixtures can achieve the same effects as any one of the first to fifth embodiments by using any lighting device A1 of the first to fifth embodiments. 8A is a downlight, and the lighting fixtures shown in FIGS. 8B and 8C are lighting fixtures that are movably attached to the wiring duct rail 202. FIG.

2 1st converter part 3 2nd converter part 4 Control part 45 1st setting part 46 2nd setting part 47 3rd setting part 100 High pressure discharge lamp (light source)
AC1 AC power supply (input power supply)

Claims (7)

  A first converter unit that converts a voltage from an input power source into a predetermined DC voltage and outputs the first DC voltage, and a first converter unit that converts the output voltage of the first converter unit into a voltage necessary for lighting a light source and supplies the voltage to the light source. 2 converter units, and a control unit for controlling the first converter unit and the second converter unit, the control unit of the output voltage of the first converter unit when the light source is not lit A first setting unit that sets a target value; a second setting unit that sets a target value of an output voltage of the first converter unit when the light source is stably lit; and a fixed period after the light source is started And a third setting unit that sets a target value of the output voltage of the first converter unit, and controls the output voltage of the first converter unit based on the target value set by each of the setting units. , Set in each setting section Shirubechi, the first setting portion, the third setting unit, the lighting apparatus characterized by decreased in the order of the second setting unit.   The lighting device according to claim 1, wherein the third setting unit decreases the target value with a constant inclination as time elapses.   The lighting device according to claim 1, wherein the third setting unit decreases the target value stepwise as time elapses.   A lamp voltage detection unit that detects a lamp voltage applied to the light source is provided, and the third setting unit decreases a target value based on the lamp voltage detected by the lamp voltage detection unit. The lighting device according to claim 1.   The second converter unit converts the output voltage of the first converter unit into a rectangular wave and outputs the rectangular wave, and the control unit is configured to output the first converter in a certain period after the light source is started. A fourth setting unit that sets a target value of the output voltage of the unit and the target value that is set is smaller than the target value that is set by the third setting unit, and in a certain period after the start of the light source The output voltage of the first converter unit is controlled based on the target value set by the third setting unit when the rectangular wave is inverted, and the target set by the fourth setting unit when the rectangular wave is not inverted The lighting device according to claim 1, wherein an output voltage of the first converter unit is controlled based on a value.   The power supply voltage detection part which detects the power supply voltage of the said input power supply is provided, A said 2nd setting part changes a target value based on the power supply voltage detected by the said power supply voltage detection part, It is characterized by the above-mentioned. 5. The lighting device according to 5.   An illumination fixture comprising: the lighting device according to any one of claims 1 to 6; and a fixture main body that holds the lighting device and the light source.

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