JP2017117740A - Power supply device and luminaire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply device and a luminaire that can perform dimming and color matching and suppress occurrence of flicker and video flicker.SOLUTION: A power supply device 1 includes a power supply circuit 3 that supplies lighting current to plural light sources 2 having different emission colors, a current breaker 4 for switching supply and stop of the lighting current corresponding to each of the plural light sources 2, and a control circuit 5 for controlling the power supply circuit 3 and the current breaker 4. The control circuit 5 associates any one of the plural light sources 2 with each of plural second periods T1, T2, T3. The control circuit 5 executes DC dimming control when an instructed dimming level (an instruction value of the dimming level) is higher than a threshold value (dimming threshold value) X1, and executes PWM dimming control when the dimming level is lower than the threshold value X1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply device and a lighting fixture.

  As a conventional example, the illumination device described in Patent Document 1 is illustrated. The illumination device described in Patent Document 1 combines light by emitting light of a first LED (Light Emitting Diode), a second LED, a third LED, and a fourth LED that emit light of different colors. The lighting device realizes light of desired chromaticity by adjusting the light output of the first to fourth LEDs. The illuminating device includes a light emitting unit composed of first to fourth LEDs, a light emission time control unit that controls a light emission time in one cycle for each of the first to fourth LEDs, and each of the first to fourth LEDs. An LED management unit that periodically controls light emission and non-light emission, and an LED drive circuit that drives each of the first to fourth LEDs.

  In the illumination device described in Patent Document 1, each of the first to fourth LEDs emits light alone, excluding the others. In the lighting device, the single light emission state of each LED is formed while maintaining the ratio of the light emission time in one cycle of each LED. The lighting device repeats light emission and non-light emission a plurality of times within one cycle for the first to fourth LEDs.

JP 2011-34788 A

  By the way, in the illuminating device of patent document 1, if each dimming level of 1st-4th LED falls, the period when none of 1st-4th LED will light-emit within 1 period will generate | occur | produce. Resulting in. As the period in which none of the first to fourth LEDs emits light becomes longer, flicker and video flicker are more likely to occur.

  The present invention has been made in view of the above-described reasons, and an object thereof is to provide a power supply device and a lighting fixture that can perform light control and color control and can suppress occurrence of flicker and video flicker.

  The power supply device of the present invention includes a power supply circuit that supplies a lighting current to a plurality of light sources having different emission colors, a current breaker that switches supply and stop of the lighting current corresponding to each of the plurality of light sources, and the power supply circuit And a control circuit for controlling the current breaker, wherein the control circuit time-divides a periodically set first period into a plurality of second periods, and each of the plurality of second periods includes the plurality of the plurality of second periods. In association with any one of the light sources, DC dimming control is executed when the instructed dimming level is higher than the threshold value in each of the plurality of second periods, and the dimming level is set to the threshold value. PWM dimming control is performed when the power is lower than the control circuit, and the control circuit in the DC dimming control controls the power supply circuit such that the higher the dimming level, the larger the amplitude of the lighting current, and Said compound And controlling the current breaker to supply the lighting current to each of the light sources corresponding to each of the second periods over the entire period of the plurality of second periods, and the PWM dimming control The control circuit controls the power supply circuit so that the amplitude of the lighting current becomes a constant value, and the higher the dimming level, the longer the supply period of the lighting current is. It is characterized by controlling.

  The lighting fixture of this invention is equipped with the above-mentioned power supply device and the said several light source from which luminescent color differs, It is characterized by the above-mentioned.

  The power supply device and the lighting fixture of the present invention are capable of light control and color control, and have the effect of suppressing the occurrence of flicker and video flicker.

1 is a circuit configuration diagram illustrating a power supply device according to a first embodiment. 2A is an explanatory diagram illustrating an operation of the first control circuit according to the first embodiment, and FIG. 2B is an explanatory diagram illustrating an operation of the signal conversion circuit. 3A is an explanatory diagram showing the relationship between the dimming level and the current ratio according to the first embodiment, FIG. 3B is an explanatory diagram showing the relationship between the dimming level and the lighting current, and FIG. 3C is a graph showing the dimming level and the ON time of the switching element. It is explanatory drawing which shows a relationship. 3 is a time chart for explaining an operation of DC dimming control of the power supply device according to the first embodiment. 3 is a time chart for explaining an operation of PWM dimming control of the power supply device according to the first embodiment. It is a perspective view which shows the lighting fixture which concerns on Embodiment 1. FIG. It is a left view which shows the lighting fixture which concerns on Embodiment 1. FIG. FIG. 6 is a circuit configuration diagram showing a power supply device according to a second embodiment. FIG. 6 is a circuit configuration diagram illustrating a main part of a power supply device according to a second embodiment. 6 is a time chart for explaining the operation of DC dimming control of the power supply device according to the second embodiment. 6 is a time chart for explaining the operation of PWM dimming control of the power supply device according to the second embodiment. FIG. 5 is a circuit configuration diagram showing a power supply device according to a third embodiment. 10 is a time chart for explaining the operation of PWM dimming control of the power supply device according to the third embodiment. 10 is a time chart for explaining an operation of PWM dimming control of another example of the power supply device according to the third embodiment.

  The following embodiments relate to a power supply device and a lighting fixture, and more particularly, to a power supply device that supplies power to light sources having different emission colors, and a lighting fixture including the power supply device. Hereinafter, embodiments of a power supply device and a lighting fixture will be described in detail with reference to the drawings.

(Embodiment 1)
The power supply device 1 of this embodiment is demonstrated with reference to FIGS. As shown in FIG. 1, the power supply device 1 turns on each of the first light source 21, the second light source 22, and the third light source 23 having different emission colors. The first light source 21 includes a plurality of red LEDs (Light Emitting Diodes) 211 that are electrically connected in series. The second light source 22 includes a plurality of green LEDs 221 that are electrically connected in series. The third light source 23 is composed of a blue LED 231 electrically connected in series. Each of the red LED 211, the green LED 221 and the blue LED 231 has a rated current defined for each. And the power supply device 1 of this embodiment is comprised so that the electric current below each rated current of the 1st light source 21, the 2nd light source 22, and the 3rd light source 23 may be sent.

  The power supply device 1 includes a current breaker 4, a power supply circuit 3, a control circuit 5, and a signal conversion circuit 6. The control circuit 5 includes a first control circuit 51 and a second control circuit 52. The current breaker 4 includes a first switching element Q1, a second switching element Q2, and a third switching element Q3.

  Each of the first switching element Q1, the second switching element Q2, and the third switching element Q3 is an n-channel MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). The drain of the first switching element Q1 is electrically connected in series to the cathode side of the first light source 21. The drain of the second switching element Q2 is electrically connected in series to the cathode side of the second light source 22. The drain of the third switching element Q3 is electrically connected in series to the cathode side of the third light source 23. The sources of the first switching element Q1, the second switching element Q2, and the third switching element Q3 are electrically connected to the output terminal of the power supply circuit 3. A series circuit composed of the first light source 21 and the first switching element Q1, a series circuit composed of the second light source 22 and the second switching element Q2, and a third light source 23 and the third switching element Q3. Each of the series circuits to be connected is electrically connected in parallel between both ends of the output end of the power supply circuit 3.

  The power supply circuit 3 includes a fourth switching element Q4, a diode D1, a step-down choke L1, and a detection resistor R1 (current detection unit). The step-down choke L1 has a primary side coil L11 and a secondary side coil L12. The fourth switching element Q4 is an n-channel MOSFET. The drain of the fourth switching element Q4 is electrically connected to the positive electrode of the DC power supply Vin. The source of the fourth switching element Q4 is electrically connected to one end that is the end of winding of the primary coil L11 of the step-down choke L1. The cathode of the diode D1 is electrically connected to the source of the fourth switching element Q4. The anode of the diode D1 is electrically connected to one end of the detection resistor R1. The other end of the detection resistor R1 is electrically connected to the negative electrode of the DC power supply Vin.

  A series circuit composed of the fourth switching element Q4, the diode D1, and the detection resistor R1 is electrically connected between both poles of the DC power supply Vin. The other end of the primary side coil L11 of the step-down choke L1 is electrically connected to each of the first light source 21, the second light source 22, and the third light source 23. The series circuit constituted by the primary coil L11 of the step-down choke L1 and the diode D1 is electrically connected between both ends of the series circuit constituted by the first light source 21 and the first switching element Q1. Further, the series circuit constituted by the primary coil L11 and the diode D1 of the step-down choke L1 is electrically connected between both ends of the series circuit constituted by the second light source 22 and the second switching element Q2. . Further, the series circuit constituted by the primary coil L11 and the diode D1 of the step-down choke L1 is electrically connected between both ends of the series circuit constituted by the third light source 23 and the third switching element Q3. .

  One end of the secondary side coil L12 of the step-down choke L1 is electrically connected to the second control circuit 52. The other end, which is the end of winding of the secondary coil L12 of the step-down choke L1, is electrically connected to the negative electrode of the DC power supply Vin.

  The first control circuit 51 includes a microcontroller having a CPU (Central Processing Unit) and a memory. The first control circuit 51 is electrically connected to the gates of the first switching element Q1, the second switching element Q2, and the third switching element Q3. The first control circuit 51 may be electrically connected to the respective gates of the switching element Q1, the switching element Q2, and the switching element Q3 via a gate driver IC or the like. The first control circuit 51 turns on and off each of the first switching element Q1, the second switching element Q2, and the third switching element Q3.

  The second control circuit 52 is electrically connected to the gate of the fourth switching element Q4. The second control circuit 52 turns on and off the fourth switching element Q4. The second control circuit 52 is electrically connected to one end of the detection resistor R1, and monitors the voltage (first detection voltage) Vr1 across the detection resistor R1. The second control circuit 52 is electrically connected to one end of the secondary coil L12 of the step-down choke L1, and monitors the voltage (second detection voltage) Vzcd across the secondary coil L12 of the step-down choke L1.

  Operations of the second control circuit 52 and the power supply circuit 3 will be described. In the following description, a case where the first switching element Q1 is controlled to be in the ON state by the first control circuit 51 will be described. The second control circuit 52 controls the fourth switching element Q4 to be in an ON state until the first detection voltage Vr1 reaches a target voltage Vth1 described later. When the fourth switching element Q4 is turned on, a lighting current flows through a path of the positive electrode of the DC power source Vin → the primary coil L11 of the step-down choke L1 → the first light source 21 → the detection resistor R1 → the negative electrode of the DC power source Vin. When the first detection voltage Vr1 reaches the target voltage Vth1, the second control circuit 52 controls the fourth switching element Q4 to be turned off. When the fourth switching element Q4 is turned off, the energy stored in the primary coil L11 of the step-down choke L1 is released, and the primary coil L11 of the step-down choke L1 → the first light source 21 → the diode D1 → the primary of the step-down choke L1. A lighting current (regenerative current) flows through the path of the side coil L11. The second control circuit 52 indirectly monitors the regenerative current from the second detection voltage Vzcd and controls the fourth switching element Q4 from the off state to the on state when the regenerative current becomes zero.

  The second control circuit 52 controls the fourth switching element Q4 in the critical mode as described above.

  Further, when the first control circuit 51 controls the second switching element Q2 to be in the on state, the second control circuit 52 turns on the fourth switching element Q4 until the first detection voltage Vr1 reaches the target voltage Vth2. Control to the state. Then, when the first detection voltage Vr1 reaches the target voltage Vth2, the second control circuit 52 controls the fourth switching element Q4 to be turned off. Further, when the first control circuit 51 controls the third switching element Q3 to be in the ON state, the second control circuit 52 turns on the fourth switching element Q4 until the first detection voltage Vr1 reaches the target voltage Vth3. Control to the state. Then, when the first detection voltage Vr1 reaches the target voltage Vth3, the second control circuit 52 controls the fourth switching element Q4 to be turned off.

  Incidentally, the first control circuit 51 performs light control and color control of the first light source 21, the second light source 22, and the third light source 23 by periodically repeating a certain first period T0. The first period T0 is composed of three second periods T1, T2, T3 and three dead times DT which are time-divided (see FIG. 4). The first control circuit 51 associates the first switching element Q1 with the second period T1, and can control the first switching element Q1 to be in the ON state within the second period T1. Further, the first control circuit 51 can associate the second switching element Q2 with the second period T2, and can control the second switching element Q2 to be in the ON state within the second period T2. Further, the first control circuit 51 can associate the third switching element Q3 with the second period T3 and control the third switching element Q3 to be in an ON state. The first control circuit 51 associates the second periods T1, T2, and T3 so that the first light source 21, the second light source 22, and the third light source 23 are not turned on in the overlapping period. Each of the three dead times DT is provided between the second period T1 and the second period T2, between the second period T2 and the second period T3, and between the second period T3 and the second period T1. ing. The first control circuit 51 includes the first switching element Q1 and the second switching element Q2 so that none of the first light source 21, the second light source 22, and the third light source 23 is lit at each of the three dead times DT. , And the third switching element Q3 are controlled to be in an OFF state.

  As shown in FIG. 1, the first control circuit 51 is configured to receive a command including a dimming signal and a toning signal from a controller called a dimming console, for example. The first control circuit 51 operates so that the light color of the illumination light matches the light color requested by the command. The dimming console has a plurality of input devices called faders. The operation positions of the plurality of faders correspond to, for example, the light amounts of red light color, green light color, and blue light color, respectively. In other words, the dimming console generates red light, green light, and blue light dimming level instruction values based on the operation positions of the faders operated by the operator, and the instruction values (instructed A command including a dimming level) is transmitted to the first control circuit 51.

  The first control circuit 51 synchronizes with each of the second periods T1, T2, and T3 to each of the first light source 21, the second light source 22, and the third light source 23 based on the instruction value of the dimming level. A corresponding dimming control signal (PWM signal) is output. As shown in FIG. 2A, when the dimming level instruction value is higher than the dimming threshold value X1, the dimming control signal has a higher on-duty as the dimming level instruction value is higher. The lower the dimming level instruction value, the lower the on-duty of the dimming control signal. When the dimming level instruction value is lower than the dimming threshold value X1, the on-duty of the dimming control signal is kept constant when the dimming level instruction value is the dimming threshold value X1.

  The signal conversion circuit 6 is an integration circuit composed of a resistor and a capacitor. As shown in FIG. 1, the signal conversion circuit 6 is electrically connected to the first control circuit 51 and the second control circuit 52. For example, the signal conversion circuit 6 integrates the dimming control signal (PWM signal) output from the first control circuit 51. The signal conversion circuit 6 outputs the integrated DC dimming voltage signal to the second control circuit 52. The higher the on-duty corresponding to each of the second periods T1, T2, T3, The value becomes higher. In addition, the voltage value of the dimming voltage signal decreases as the on-duty corresponding to each of the second periods T1, T2, and T3 decreases.

  In FIG. 2B, the horizontal axis represents the voltage value of the dimming voltage signal, and the vertical axis represents the target voltage Vth. The target voltage Vth indicates any one of the target voltages Vth1, Vth2, and Vth3. When the instruction value of the dimming level is higher than the dimming threshold value X1, as shown in FIG. 2B, the target voltage Vth increases as the voltage value of the dimming voltage signal increases (as the on-duty of the dimming control signal increases). Becomes higher. When the dimming level instruction value is lower than the dimming threshold value X1, a constant on-duty dimming control signal is transmitted from the first control circuit 51. Therefore, the dimming level instruction value is dimmed as the target voltage Vth. The target voltage Vth at the threshold value X1 is maintained.

  By the way, the first control circuit 51 selectively selects the DC dimming control and the PWM dimming control based on the dimming level instruction value to select the first light source 21, the second light source 22, and the third light source 23. Control the dimming level. Here, as an example, the first light source 21 will be described with reference to FIGS. 3A, 3B, and 3C. In FIG. 3A, the dimming level indicating value corresponding to the first light source 21 is shown on the horizontal axis, and the current actually supplied to the first light source 21 with respect to the rated current of the red LED 211 is shown on the vertical axis. The ratio (current ratio) is shown. As shown in FIG. 3A, the ratio of the current supplied to the first light source 21 increases as the indication value of the dimming level corresponding to the first light source 21 increases. The maximum value of the dimming level instruction value corresponding to the first light source 21 corresponds to the case where the rated current is supplied to the first light source 21.

  In the first control circuit 51, a dimming threshold value X1 is stored in advance in a memory, for example. The dimming threshold value X1 indicates a boundary between the DC dimming control and the PWM dimming control. The first control circuit 51 sets the dimming level of the first light source 21 by DC dimming control when the indication value of the dimming level of the first light source 21 transmitted from the dimming console is higher than the dimming threshold value X1. Control. Further, the first control circuit 51 controls the dimming of the first light source 21 by the PWM dimming control when the instruction value of the dimming level of the first light source 21 transmitted from the dimming console is lower than the dimming threshold X1. Control the level.

  As shown in FIGS. 3B and 3C, the first control circuit 51 in the DC dimming control increases the amplitude (peak value Ip0) of the lighting current of the first light source 21 as the dimming level instruction value increases ( The first switching element Q1 is controlled to be in the ON state over the entire period of the second period T1 (see FIG. 3B).

  Note that the peak value Ip0 of the lighting current of the first light source 21 at the dimming threshold value X1 corresponds to the minimum value Ip1. The first control circuit 51 in the PWM dimming control maintains the lighting current amplitude at the minimum value Ip1 (see FIG. 3B), and the higher the dimming level, the on-time t1 of the first switching element Q1 in the second period T1. (See FIG. 3C).

  In the first control circuit 51, a dimming threshold value X2 corresponding to the second light source 22 and a dimming threshold value X3 corresponding to the third light source 23 are stored in advance in, for example, a memory. When the indication value of the dimming level of the second light source 22 is higher than the dimming threshold value X2, the first control circuit 51 controls the dimming level of the second light source 22 by DC dimming control. Further, when the instruction value of the dimming level of the second light source 22 is lower than the dimming threshold value X2, the first control circuit 51 controls the dimming level of the second light source 22 by PWM dimming control. Furthermore, when the instruction value of the dimming level of the third light source 23 is higher than the dimming threshold value X3, the first control circuit 51 controls the dimming level of the third light source 23 by DC dimming control. Further, when the instruction value of the dimming level of the third light source 23 is lower than the dimming threshold value X3, the first control circuit 51 controls the dimming level of the third light source 23 by PWM dimming control.

  The dimming threshold values X1, X2, and X3 corresponding to the first light source 21, the second light source 22, and the third light source 23 may be different from each other.

  Further, the peak value Ip0 of the lighting current of the second light source 22 at the dimming threshold value X2 corresponding to the second light source 22 is set to the minimum value Ip2 of the lighting current of the second light source 22, as shown in FIGS. Equivalent to. Further, the peak value Ip0 of the lighting current of the third light source 23 at the dimming threshold value X3 corresponding to the third light source 23 corresponds to the minimum value Ip3 of the lighting current of the third light source 23.

  In the PWM dimming control, the time during which the first control circuit 51 controls the second switching element Q2 to be in the ON state within the second period T2 is defined as an on time t2. In the PWM dimming control, the time during which the first control circuit 51 controls the third switching element Q3 to be in the on state within the second period T3 is defined as an on time t3.

  In order to correspond to the low dimming levels of the first light source 21, the second light source 22, and the third light source 23, the first control circuit 51 includes a first switching element Q1, a second switching element Q2, and a third light control level. PWM dimming control is performed by varying the respective on times t1, t2, and t3 of the switching element Q3 (see FIG. 5).

  In the power supply device of the comparative example, as shown in FIG. 3B and FIG. 3C, the amplitude value of the lighting current flowing through the light source is made constant, and the larger the dimming level instruction value, the more electrically connected in series with the light source. The light source is dimmed and controlled by extending the ON time by the switching element.

  The operation of the power supply device 1 in the DC dimming control will be described with reference to FIG. 1 and FIG. Note that Vg1 shown in FIG. 4 represents a voltage applied to the gate of the first switching element Q1. Vg2 shown in FIG. 4 indicates a voltage applied to the gate of the second switching element Q2. Vg3 shown in FIG. 4 indicates a voltage applied to the gate of the third switching element Q3. Vg4 shown in FIG. 4 indicates a voltage applied to the gate of the fourth switching element Q4.

  As shown in FIG. 1, the first control circuit 51 receives a command transmitted from the dimming console. The command includes instruction values for the dimming level of the first light source 21, the dimming level of the second light source 22, and the dimming level of the third light source 23.

  As shown in FIG. 4, the first control circuit 51 controls the first switching element Q1 to be in an ON state when the second period T1 is started. The first control circuit 51 transmits a dimming control signal corresponding to the first light source 21 to the signal conversion circuit 6 based on the instruction value of the dimming level included in the command. The signal conversion circuit 6 integrates the dimming control signal and converts it into a DC dimming voltage signal. During the second period T1, the first control circuit 51 controls the second switching element Q2 and the third switching element Q3 to be in an off state.

  The second control circuit 52 receives the dimming voltage signal from the signal conversion circuit 6 and sets the target voltage Vth1 corresponding to the first light source 21. The second control circuit 52 controls the fourth switching element Q4 to be in an on state until the first detection voltage Vr1 reaches the target voltage Vth1. Further, when the first detection voltage Vr1 reaches the target voltage Vth1, the second control circuit 52 controls the fourth switching element Q4 to be turned off. The second control circuit 52 maintains the fourth switching element Q4 in the off state until the second detection voltage Vzcd becomes zero. When the second detection voltage Vzcd becomes zero, the second control circuit 52 controls the fourth switching element Q4 to be in an on state. In this way, the second control circuit 52 performs switching control of the fourth switching element Q4 over the entire period of the second period T1.

  When the second period T1 ends, the first control circuit 51 controls the first switching element Q1 to the off state. After the dead time DT elapses, the second period T2 is started, and the first control circuit 51 controls the second switching element Q2 to the on state and sets the dimming level indication value corresponding to the second light source 22 to the second light source 22. Based on the dimming control signal, the signal conversion circuit 6 is transmitted. At this time, the first control circuit 51 controls the third switching element Q3 to be turned off.

  The second control circuit 52 receives the dimming voltage signal from the signal conversion circuit 6 and sets the target voltage Vth2. The second control circuit 52 controls the fourth switching element Q4 to be on until the first detection voltage Vr1 reaches the target voltage Vth2. In addition, when the first detection voltage Vr1 reaches the target voltage Vth2, the second control circuit 52 controls the fourth switching element Q4 to be turned off. The second control circuit 52 maintains the fourth switching element Q4 in the off state until the second detection voltage Vzcd becomes zero. When the second detection voltage Vzcd becomes zero, the second control circuit 52 controls the fourth switching element Q4 to be in an on state. In this way, the second control circuit 52 performs switching control of the fourth switching element Q4 over the entire period of the second period T2.

  When the second period T2 ends, the first control circuit 51 controls the second switching element Q2 to be turned off. After the dead time DT elapses, the second period T3 is started, and the first control circuit 51 controls the third switching element Q3 to be in the ON state and sets the dimming level indication value corresponding to the third light source 23 to Based on the dimming control signal, the signal conversion circuit 6 is transmitted. At this time, the first control circuit 51 controls the first switching element Q1 to the off state.

  The second control circuit 52 receives the dimming voltage signal from the signal conversion circuit 6 and sets the target voltage Vth3 corresponding to the third light source 23. The second control circuit 52 controls the fourth switching element Q4 to be turned on until the first detection voltage Vr1 reaches the target voltage Vth3. Further, when the first detection voltage Vr1 reaches the target voltage Vth3, the second control circuit 52 controls the fourth switching element Q4 to be turned off. The second control circuit 52 maintains the fourth switching element Q4 in the off state until the second detection voltage Vzcd becomes zero. When the second detection voltage Vzcd becomes zero, the second control circuit 52 controls the fourth switching element Q4 to be in an on state. In this way, the second control circuit 52 performs switching control of the fourth switching element Q4 over the entire period of the second period T3.

  When the second period T3 ends, the first control circuit 51 controls the third switching element Q3 to be turned off. After the dead time DT elapses, the second period T1 is started, the first switching element Q1 is controlled to be turned on, and the dimming control signal based on the indication value of the dimming level corresponding to the first light source 21 is converted into a signal. Transmit to circuit 6. In this way, the power supply device 1 of the present embodiment performs light adjustment and color adjustment by periodically repeating the first period T0.

  Next, in the second period T1, T2, T3, the indication values of the dimming levels of the first light source 21, the second light source 22, and the third light source 23 are from the corresponding dimming threshold values X1, X2, X3. The case where the value is also low will be described. The power supply device 1 controls the dimming levels of the first light source 21, the second light source 22, and the third light source 23 by PWM dimming control. The operation of the power supply device 1 in PWM control will be described with reference to FIG.

  Hereinafter, a case where the on-duty of the first switching element Q1 in the second period T1 is 50% will be described. The first control circuit 51 controls the first switching element Q1 to an on state. When the second period T1 is started, the first control circuit 51 sends a dimming control signal corresponding to the first light source 21 to the signal conversion circuit 6 based on the instruction value of the dimming level, as shown in FIG. Send to. At this time, since the indication value of the dimming level is lower than the dimming threshold value X1, the target voltage Vth1 becomes a voltage value corresponding to the minimum value Ip1. The signal conversion circuit 6 integrates the dimming control signal and converts it to a dimming voltage signal. The second switching element Q2 and the third switching element Q3 are controlled to be in an off state.

  The second control circuit 52 receives the dimming voltage signal from the signal conversion circuit 6 and sets the target voltage Vth1. The second control circuit 52 controls the fourth switching element Q4 to be in an on state until the first detection voltage Vr1 reaches the target voltage Vth1. When the first detection voltage Vr1 reaches the target voltage Vth1, the second control circuit 52 controls the fourth switching element Q4 to be turned off. The second control circuit 52 maintains the fourth switching element Q4 in the off state until the second detection voltage Vzcd becomes zero. When the second detection voltage Vzcd becomes zero, the second control circuit controls the fourth switching element Q4 to be in an on state.

  At this time, the first control circuit 51 controls the first switching element Q1 to be in an on state until an on time t1 that is a length of T1 / 2 has elapsed from the start of the second period T1. And the 1st control circuit 51 will control the 1st switching element Q1 to an OFF state, if the ON time t1 of 2nd period T1 passes.

  When the second period T1 ends, the first control circuit 51 maintains the first switching element Q1 in the off state. After the dead time DT elapses, the second period T2 is started, and the first control circuit 51 controls the second switching element Q2 to the on state and sets the dimming level indication value corresponding to the second light source 22 to the second light source 22. Based on the dimming control signal, the signal conversion circuit 6 is transmitted. During the second period T2, the first control circuit 51 controls the third switching element Q3 to be turned off.

  A case where the on-duty of the second switching element Q2 in the second period T2 is 75% will be described. The first control circuit 51 transmits a dimming control signal corresponding to the second light source 22 to the signal conversion circuit 6 based on the instruction value of the dimming level. The signal conversion circuit 6 integrates the dimming control signal and converts it to a dimming voltage signal. Since the instructed dimming level is lower than the dimming threshold value X2, the target voltage Vth2 becomes a voltage value corresponding to the minimum value Ip2.

  The second control circuit 52 receives the dimming voltage signal from the signal conversion circuit 6 and sets the target voltage Vth2 (see FIG. 5). The second control circuit 52 controls the fourth switching element Q4 to be on until the first detection voltage Vr1 reaches the target voltage Vth2. When the first detection voltage Vr1 reaches the target voltage Vth2, the second control circuit 52 controls the fourth switching element Q4 to be turned off. The second control circuit 52 maintains the fourth switching element Q4 in the off state until the second detection voltage Vzcd becomes zero. When the second detection voltage Vzcd becomes zero, the second control circuit controls the fourth switching element Q4 to be in an on state.

  At this time, the first control circuit 51 controls the second switching element Q2 to be in an on state until an on time t2 that is a length of (3 × T2) / 4 has elapsed from the start of the second period T2. . Then, the first control circuit 51 controls the second switching element Q2 to be in an OFF state when the ON time t2 of the second period T2 has elapsed.

  When the second period T2 ends, the first control circuit 51 maintains the second switching element Q2 in the off state. After the dead time DT elapses, the second period T3 is started, and the first control circuit 51 controls the third switching element Q3 to be in the ON state and sets the dimming level indication value corresponding to the third light source 23 to Based on the dimming control signal, the signal conversion circuit 6 is transmitted. During the second period T2, the first control circuit 51 controls the first switching element Q1 to be turned off.

  A case where the on-duty of the third switching element Q3 in the second period T3 is 25% will be described. The first control circuit 51 transmits a dimming control signal corresponding to the third light source 23 to the signal conversion circuit 6 based on the instruction value of the dimming level. The signal conversion circuit 6 integrates the dimming control signal and converts it to a dimming voltage signal. Since the instructed dimming level is lower than the dimming threshold value X3, the target voltage Vth3 becomes a voltage value corresponding to the minimum value Ip3.

  The second control circuit 52 receives the dimming voltage signal from the signal conversion circuit 6 and sets the target voltage Vth3. The second control circuit 52 controls the fourth switching element Q4 to be turned on until the first detection voltage Vr1 reaches the target voltage Vth3. When the first detection voltage Vr1 reaches the target voltage Vth3, the second control circuit 52 controls the fourth switching element Q4 to be turned off. The second control circuit 52 maintains the fourth switching element Q4 in the off state until the second detection voltage Vzcd becomes zero. When the second detection voltage Vzcd becomes zero, the second control circuit controls the fourth switching element Q4 to be in an on state.

  At this time, the first control circuit 51 controls the third switching element Q3 to be in an ON state until an ON time t3 that is a length of (1 × T3) / 4 has elapsed from the start of the second period T3. . And the 1st control circuit 51 will control the 3rd switching element Q3 to an OFF state, if the ON time t3 of 2nd period T3 passes.

  When the second period T3 ends, the first control circuit 51 maintains the third switching element Q3 in the off state. After the dead time DT elapses, the second period T1 is started, and the first control circuit 51 controls the first switching element Q1 to the ON state and sets the indication value of the dimming level corresponding to the first light source 21. Based on the dimming control signal, the signal conversion circuit 6 is transmitted.

  In the power supply device 1 of this embodiment, in the DC dimming control, the lighting current peak value Ip0 is changed corresponding to the dimming level instruction value. As a result, the difference in brightness between when the first light source 21, the second light source 22, and the third light source 23 are turned on and when they are turned off is small compared to the comparative example (see FIG. 3B). ). Moreover, in the power supply device 1 of this embodiment, in DC dimming control, the period when all of the 1st light source 21, the 2nd light source 22, and the 3rd light source 23 are not lighting is short compared with a comparative example ( (See FIG. 3C). Therefore, the power supply device 1 of the present embodiment can perform light adjustment and color adjustment by periodically executing the first period T0, and can suppress occurrence of flicker and video flicker.

  In the power supply device 1 of the present embodiment, the peak value Ip0 of the lighting current corresponds to the minimum values Ip1, Ip2, and Ip3 in the PWM dimming control. As a result, the difference in brightness between when the first light source 21, the second light source 22, and the third light source are turned on and when they are turned off is small compared to the comparative example. (See FIG. 3B). Moreover, in the power supply device 1 of this embodiment, in PWM dimming control, the period when all of the 1st light source 21, the 2nd light source 22, and the 3rd light source 23 are not lighting is short compared with a comparative example ( (See FIG. 3C). Therefore, the power supply device 1 of the present embodiment can perform light adjustment and color adjustment by periodically executing the first period T0, and can suppress occurrence of flicker and video flicker.

  Note that the number of light sources 2 and emission colors described in the present embodiment are merely examples, and are not limited. In addition, each of the plurality of red LEDs 211, the plurality of green LEDs 221 and the plurality of blue LEDs 231 may be electrically connected in parallel. Moreover, each of the plurality of red LEDs 211, the plurality of green LEDs 221 and the plurality of blue LEDs 231 may be electrically connected by combining series connection and parallel connection.

  In the power supply device 1 of the present embodiment, the PWM dimming control is performed in the case where the DC dimming control is performed in all of the second periods T1, T2, T3 and in the second periods T1, T2, T3. The case where it is performed is explained. However, the power supply device 1 may perform DC dimming control only in the second period T1, and perform PWM dimming control in the second periods T2 and T3, for example. That is, the power supply device 1 performs DC dimming control and PWM dimming based on the dimming level instruction values of the first light source 21, the second light source 22, and the third light source 23 within the first period T0. In combination with the control, the first period T0 may be periodically repeated for light control and color adjustment.

  The power supply device 1 of the present embodiment includes a power supply circuit 3 that supplies a lighting current to a plurality of light sources 2 (first light source 21, second light source 22, and third light source 23) having different emission colors. The power supply device 1 further includes a current breaker 4 (first switching element Q1, second switching element Q2, and third switching element Q3) that switches between supply and stop of the lighting current corresponding to each of the plurality of light sources 2. The power supply device 1 further includes a control circuit 5 (a first control circuit 51 and a second control circuit 52) that controls the power supply circuit 3 and the current breaker 4. The control circuit 5 time-divides the periodically set first period T0 into a plurality of second periods T1, T2, T3, and each of the plurality of light sources 2 is divided into each of the plurality of second periods T1, T2, T3. Associate one or the other. When the instructed dimming level (dimming level instruction value) is higher than threshold values (dimming threshold values) X1, X2, and X3 in each of the plurality of second periods T1, T2, and T3, the control circuit 5 DC dimming control is executed, and PWM dimming control is executed when the dimming level is lower than the threshold values X1, X2, and X3. The control circuit 5 in the DC dimming control controls the power supply circuit 3 so that the amplitude of the lighting current increases as the dimming level increases. The control circuit 5 in the DC dimming control further applies the light source 2 corresponding to each of the plurality of second periods T1, T2, T3 over the entire period of each of the plurality of second periods T1, T2, T3. The current breaker 4 is controlled so as to supply the lighting current. The control circuit 5 in the PWM dimming control controls the power supply circuit 3 so that the amplitude of the lighting current becomes a constant value, and the current breaker so that the supply period of the lighting current becomes longer as the dimming level is higher. 4 is controlled.

  Since the power supply device 1 of the present embodiment is configured as described above, it is possible to perform light adjustment and color adjustment, and to suppress the occurrence of flicker and video flicker.

  In the power supply device 1 of the present embodiment, the control circuit 5 preferably includes a first control circuit 51 and a second control circuit 52. The first control circuit 51 preferably controls the current breaker 4. The second control circuit 52 preferably controls the power supply circuit 3.

  If the power supply device 1 of this embodiment is comprised as mentioned above, each of the 1st control circuit 51 and the 2nd control circuit 52 can divide | segment a circuit for every control object.

  The lighting fixture 10 of this embodiment is demonstrated about FIG. 6 and FIG. The lighting fixture 10 of this embodiment is what is called a horizont light used for the purpose of illuminating a background wall (horizont) such as a studio or a stage of a television station. However, the lighting fixture to which the technical idea of the present embodiment can be applied is not limited to a horizont light. In the following description, in FIG. 6, the vertical and horizontal directions and the front and rear directions are defined.

  The luminaire 10 includes a light source unit 20 including a first light source 21, a second light source 22, and a third light source 23, and a power supply unit 7.

  As illustrated in FIG. 6, the light source unit 20 includes four LED modules 200, a first housing 24, a reflection block 25, and a heat dissipation plate block 26. Each of the four LED modules 200 is configured by mounting a plurality of red LEDs 211, a plurality of green LEDs 221 and a plurality of blue LEDs 231 on the surface of a rectangular substrate.

  A receptacle connector is mounted on each surface of the substrate. The plurality of terminals included in these receptacle connectors are electrically connected to each of the plurality of red LEDs 211, the plurality of green LEDs 221 and the plurality of blue LEDs 231 via a conductor (copper foil) formed on the front surface or the back surface of the substrate. It is connected to the. Further, the receptacle connector is electrically connected to the output end of the power supply device 1 via a power cable.

  As shown in FIG. 6, the first housing 24 is formed in a rectangular parallelepiped shape by a metal plate. The first housing 24 is provided with a rectangular window hole 240 that opens to the front surface. The four LED modules 200 are accommodated in the first casing 24 in two rows in the vertical and horizontal directions with the surface facing the window holes 240.

  The reflection block 25 includes a plurality of reflection plates 251 and a light shielding plate 252. The plurality of reflection plates 251 and the light shielding plate 252 are disposed between the window hole 240 and each of the four LED modules 200 in the first housing 24 and are emitted from each of the four LED modules 200. Configured to control light distribution.

  The heat radiating plate block 26 includes a large number of heat radiating plates 260, and each of the heat radiating plates 260 is arranged at regular intervals along the thick plate direction. The heat sink block 26 is provided on the rear surface of the first housing 24. The heat sink block 26 is preferably thermally coupled to each of the four LED modules 200 in the first housing 24.

  The power supply unit 7 includes a power supply device 1, a second housing 11 that houses the power supply device 1, and a pair of arms 12. The power supply unit 7 preferably further includes a power conversion unit. The power conversion unit includes circuit components for converting AC power from the outside into DC power.

  The second casing 11 is formed in a flat rectangular parallelepiped shape by a metal plate and is configured to accommodate the power supply device 1. The pair of arms 12 are provided so as to rise upward from the left and right ends of the second housing 11. The pair of arms 12 are formed so as to gradually narrow the width dimension in the front-rear direction toward the tip. A so-called insertion hole into which the bolt of the knob bolt 13 is inserted is provided at the tip portion of the pair of arms 12. That is, the pair of arms 12 is configured to rotatably support the light source unit 20 by screwing the knob bolts 13 inserted into the insertion holes at the distal end portions into the female screws provided on the left and right ends of the first housing 24. It is configured.

  As illustrated in FIG. 7, the lighting fixture 10 of the present embodiment is installed on the floor 102 with the window hole 240 of the light source unit 20 facing the background wall surface 101 and away from the background wall surface 101, for example.

  The lighting fixture 10 of the present embodiment includes the power supply device 1 so that light control and color adjustment are possible, and flicker and video flicker can be suppressed.

  In addition, the lighting fixture 10 of this embodiment may be a projector used outdoors.

  The lighting fixture 10 of the present embodiment includes a power supply device 1 and a plurality of light sources 2 having different emission colors.

  Since the lighting fixture 10 of this embodiment is comprised as mentioned above, light control and color adjustment are possible, and generation | occurrence | production of a flicker and video flicker can be suppressed.

(Embodiment 2)
A power supply device 1A according to the present embodiment will be described with reference to FIGS. The power supply device 1A of the present embodiment is different from that of the first embodiment in that it further includes a bias circuit 8 and a voltage dividing resistor R2. In addition, about the structure which overlaps with Embodiment 1, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  As shown in FIG. 8, the first control circuit 51 synchronizes with each of the second periods T1, T2, and T3 based on the dimming level instruction value, and the first light source 21, the second light source 22, and A dimming control signal (PWM signal) corresponding to each of the third light sources 23 is output. In the dimming control signal in the DC dimming control, the on-duty of the dimming control signal decreases as the dimming level instruction value increases. In addition, in the dimming control signal in the DC dimming control, the on-duty of the dimming control signal increases as the dimming level instruction value decreases. Further, the dimming control signal in the PWM dimming control is maintained at a constant on-duty when the dimming level instruction value is the dimming threshold X1. That is, as compared with the dimming control signal of the first embodiment, the dimming control signal of the present embodiment corresponds to a signal obtained by inverting the on-duty of the dimming control signal described in the first embodiment.

  The signal conversion circuit 6 integrates the dimming control signal (PWM signal) output from the first control circuit 51, and outputs the integrated DC dimming voltage signal to the bias circuit 8. When the indication value of the dimming level is higher than the predetermined dimming threshold value X1, the dimming voltage signal has a lower voltage value as the dimming level indication value is higher, and a lower dimming level indication value. The voltage value increases. When the dimming level instruction value is lower than the predetermined dimming threshold value X1, the dimming voltage signal is maintained at a maximum voltage value that is a voltage value when the dimming level instruction value is the dimming threshold value X1.

  As shown in FIG. 9, the bias circuit 8 includes an operational amplifier OP1, voltage dividing resistors Ra and Rb, and the like. The input terminal (minus) of the operational amplifier OP1 is electrically connected to the output terminal of the operational amplifier OP1. The input terminal (plus) of the operational amplifier OP1 is electrically connected to the signal conversion circuit 6, and a DC dimming voltage signal output from the signal conversion circuit 6 is input thereto. The operational amplifier OP1 forms a buffer circuit and outputs a dimming voltage signal.

  One end of the voltage dividing resistor Ra is electrically connected to the output terminal of the operational amplifier OP1. The other end of the voltage dividing resistor Ra is electrically connected to the second control circuit 52. One end of the voltage dividing resistor Rb is electrically connected to the other end of the voltage dividing resistor Ra. The other end of the voltage dividing resistor Rb is electrically connected to the ground (for example, the negative electrode of the DC power supply Vin).

  In each of the plurality of second periods T1, T2, and T3 in DC dimming control, the on-duty of the dimming control signal increases as the dimming level instruction value decreases. Therefore, since the signal conversion circuit 6 smoothes the dimming control signal and outputs the dimming voltage signal, the bias circuit 8 outputs a DC voltage having a smaller amplitude as the dimming level instruction value is higher (FIG. 10). reference).

  In each of the plurality of second periods T1, T2, and T3 in the PWM dimming control, the on-duty of the dimming control signal is kept constant when the dimming level instruction value is the dimming threshold value X1. Therefore, in the PWM dimming control, the signal conversion circuit 6 outputs the dimming voltage signal having the maximum voltage value based on the on-duty when the dimming level instruction value is the dimming threshold value X1, so that the bias circuit 8 is constant. A DC voltage having an amplitude is output (see FIG. 11).

  One end of the voltage dividing resistor R2 is electrically connected to one end of the detection resistor R1. The other end of the voltage dividing resistor R2 is electrically connected to the output side of the bias circuit 8.

  To the second control circuit 52, a superimposed voltage Vis obtained by superimposing the first detection voltage Vr1 and the output voltage of the bias circuit 8 is input.

  Therefore, the second control circuit 52 sets the target voltage Vth corresponding to the first light source 21, the second light source 22, and the third light source 23. The target voltage Vth of the present embodiment is a constant value in any case during the second periods T1, T2, and T3.

  FIG. 10 shows the operation of the power supply device 1A in the DC dimming control. FIG. 11 shows the operation of the power supply device 1B in the PWM dimming control.

  As shown in FIGS. 10 and 11, when the superimposed voltage Vis reaches the target voltage Vth, the second control circuit 52 switches the fourth switching element Q4 from the on state to the off state. When the second detection voltage Vzcd becomes zero, the second control circuit 52 switches the fourth switching element Q4 from the off state to the on state.

  The power supply device 1A of the present embodiment preferably further includes a bias circuit 8. The power supply circuit 3 includes a switching element (fourth switching element) Q4 connected in series to a parallel circuit of a plurality of light sources 2, and a current detection unit (detection resistor R1) that outputs a detection voltage Vr1 that is a voltage corresponding to a lighting current. It is preferable to comprise. The bias circuit 8 preferably outputs a DC voltage having a larger amplitude as the dimming level is lower in each of the plurality of second periods T1, T2, and T3. The control circuit 5 preferably compares the superposed voltage Vis obtained by superimposing the detection voltage Vr1 on the DC voltage with the target voltage Vth, and controls the switching element Q4 to be turned off when the superposed voltage Vis reaches the target voltage Vth.

  In any of the second periods T1, T2, and T3, the power supply device 1A of the present embodiment sets the target voltage Vth regardless of the dimming levels of the first light source 21, the second light source 22, and the third light source 23. Dimming and toning can be performed with a constant value.

(Embodiment 3)
A power supply device 1B according to the present embodiment will be described with reference to FIGS. The power supply device 1B of the present embodiment is configured such that the first control circuit 51 instructs the second control circuit 52 to turn on the second switching element Q4 from the off state to the on state. Is different. The first control circuit 51 can control the fourth switching element Q4 not only in the critical mode but also in the continuous mode and the discontinuous mode. Note that the power supply device 1B of the present embodiment can be used in combination with the first embodiment. The same components as those in the first embodiment or the second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The first control circuit 51 is electrically connected to the second control circuit 52 as shown in FIG. The first control circuit 51 is configured to output an ON voltage signal Von to the second control circuit. The second control circuit 52 is configured to switch the first switching element Q4 from the off state to the on state when the on voltage signal Von is input.

  One end of the secondary coil L12 of the step-down choke L1 is electrically connected to the first control circuit 51, and monitors the second detection voltage Vzcd.

  For example, as shown in FIG. 13, the first control circuit 51 in the continuous mode outputs the ON voltage signal Von to the second control circuit 52 earlier than the second detection voltage Vzcd reaches zero. When the on voltage signal Von is input from the first control circuit 51, the second control circuit 52 switches the fourth switching element Q4 from the off state to the on state. In this way, the second control circuit 52 performs switching control of the fourth switching element Q4.

  In the power supply device 1B of this embodiment, the high frequency ripple current of the power supply circuit 3 can be reduced in the continuous mode.

  Further, for example, as shown in FIG. 14, the first control circuit 51 in the discontinuous mode receives the on-voltage signal Von when the second detection voltage Vzcd reaches zero and a predetermined period elapses. To 52. When the on voltage signal Von is input from the first control circuit 51, the second control circuit 52 switches the fourth switching element Q4 from the off state to the on state. In this way, the second control circuit 52 performs switching control of the fourth switching element Q4.

  In the power supply device 1B of the present embodiment, in the discontinuous mode, deep light control can be performed on the first light source 21, the second light source 22, and the third light source 23 as compared to the critical mode.

DESCRIPTION OF SYMBOLS 1 Power supply device 1A Power supply device 10 Lighting fixture 2 Light source 21 1st light source 22 2nd light source 23 3rd light source 3 Power supply circuit 4 Current circuit breaker 5 Control circuit 51 1st control circuit 52 2nd control circuit 8 Bias circuit Q1 1st switching Element Q2 Second switching element Q3 Third switching element Q4 Fourth switching element R1 Detection resistor T0 First period T1, T2, T3 Second period Vis superimposed voltage Vr1 first detection voltage (detection voltage)
Vth target voltage X1, X2, X3 Dimming threshold

Claims (4)

A power supply circuit that supplies a lighting current to a plurality of light sources having different emission colors, a current breaker that switches supply and stop of the lighting current corresponding to each of the plurality of light sources, and a control of the power supply circuit and the current breaker And a control circuit that
The control circuit time-divides a periodically set first period into a plurality of second periods, and associates any one of the plurality of light sources with each of the plurality of second periods. In each of the second periods, DC dimming control is performed when the instructed dimming level is higher than the threshold, and PWM dimming control is performed when the dimming level is lower than the threshold,
The control circuit in the DC dimming control controls the power supply circuit such that the higher the dimming level, the larger the amplitude of the lighting current, and the light source corresponding to each of the plurality of second periods In contrast, the current breaker is controlled to supply the lighting current over each of the plurality of second periods,
The control circuit in the PWM dimming control controls the power supply circuit so that the amplitude of the lighting current becomes a constant value, and the higher the dimming level, the longer the supply period of the lighting current. And controlling the current breaker. The control circuit includes a first control circuit and a second control circuit,
The first control circuit controls the current breaker;
The power supply apparatus according to claim 1, wherein the second control circuit controls the power supply circuit. A bias circuit;
The power supply circuit includes a switching element connected in series to a parallel circuit of the plurality of light sources, and a current detection unit that outputs a detection voltage that is a voltage corresponding to the lighting current,
In each of the plurality of second periods, the bias circuit outputs a DC voltage having a larger amplitude as the dimming level is lower,
The control circuit compares a superimposed voltage obtained by superimposing the detection voltage on the DC voltage with a target voltage, and controls the switching element to be turned off when the superimposed voltage reaches the target voltage. The power supply device according to claim 1 or 2. A lighting apparatus comprising: the power supply device according to claim 1; and the plurality of light sources having different emission colors.

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