JP2016110874A - Lighting device and illumination equipment - Google Patents

Abstract

An object of the present invention is to improve the stability of operation during restart. A lighting device includes a buck converter, a control circuit, a bootstrap circuit, a first control power circuit, and a second control power circuit. The bootstrap circuit is configured to generate a drive voltage HVcc necessary for the control circuit 41 to drive the switching elements Q21 and Q22 of the buck converter 40 on and off. The first control power supply circuit 42 is configured to supply the first control power supply voltage Vcc to the bootstrap circuit. The second control power supply circuit 43 is configured to generate the drive voltage HVcc only when the bootstrap circuit cannot operate normally. [Selection] Figure 1

Description

  The present invention relates to a lighting device and a lighting fixture, and more particularly, to a lighting device that lights a solid light emitting element such as a light emitting diode, and a lighting fixture including the lighting device.

  As a conventional example, a lighting device and a lighting fixture described in Patent Document 1 are illustrated. The lighting device described in Patent Literature 1 includes a step-down chopper unit (buck converter), a drive unit, a control unit, a control power supply unit, a timer unit, a second impedance element, a control capacitor, and a diode. Prepare.

  The DC power supply unit is constituted by, for example, a full-wave rectifier and a boost chopper circuit (power factor correction circuit), and is configured to output a DC voltage higher than the power supply voltage of the commercial AC power supply.

  The control unit generates a control signal for on / off control of the switching element of the step-down chopper unit.

  A drive part outputs a drive signal to a switching element by the input of the control signal produced | generated by the control part.

  The control power supply unit supplies at least the control power supply (for example, 15 volt DC power supply) to the drive unit according to the voltage generated at the output terminal of the DC power supply unit.

  The timer unit outputs a signal for on / off control of the switching element to the control unit after a predetermined time after the control power is supplied to the drive unit.

  The second impedance element has a second impedance having a resistance component in a path in which the control capacitor can be DC-charged from the control power supply unit when the switching element is not performing the on / off operation. The second impedance element is electrically connected between the connection point of the switching element and the inductor (choke coil) of the step-down chopper circuit and the ground.

  The connection point corresponding to the source potential of the switching element corresponds to the midpoint potential, and the switching element itself is provided on the higher voltage side than the midpoint potential. Therefore, a correspondingly high gate voltage is required for the on / off operation of the switching element, and a bias by the control capacitor is required.

  On the other hand, it is desirable to lower the potential at the connection point as much as possible to the ground level as much as possible during the non-on / off operation of the switching element, that is, when the lighting device is activated. When the potential at the connection point drops to the ground level, a current flows from the control power supply unit to the control capacitor, and the control capacitor is charged.

  Therefore, in this conventional example, the second impedance element is arranged on the low potential side of the control capacitor when viewed from the control power supply unit, and the control capacitor can be DC-charged when the switching element is not turned on / off. Yes.

JP2013-127939A

  However, in the conventional example described in Patent Document 1, for example, in the state where the charge charge remains in the output capacitor (smoothing capacitor) of the step-down chopper unit at the time of restart after an instantaneous power failure, the potential at the connection point is Will remain high. As a result, the charging current does not flow from the control power supply unit to the control capacitor, and the drive unit cannot turn on the switching element of the step-down chopper unit.

  The present invention has been made in view of the above problems, and an object thereof is to improve the stability of operation at the time of restart.

  The lighting device of the present invention is a lighting device for lighting a light source having a solid state light emitting element, and includes a switching element provided on a higher potential side than the light source, and the switching element is turned on / off to drive a direct current. A switching power supply circuit that converts an input voltage into a DC voltage required for the light source, a drive circuit that drives the switching element on and off, a control circuit that controls the operation of the switching power supply circuit through the drive circuit, and the drive A bootstrap circuit that generates a drive voltage necessary for the circuit to drive the switching element on and off, a first control power supply circuit that supplies power to the bootstrap circuit, and the bootstrap circuit cannot operate normally And a second control power supply circuit for generating the driving voltage only.

  The lighting fixture of this invention has the said lighting device and the said light source lighted by the said lighting device, It is characterized by the above-mentioned.

  The lighting device and the lighting fixture of the present invention have an effect that the stability of the operation at the time of restart can be improved.

It is a circuit diagram which shows Embodiment 1 of the lighting device which concerns on this invention. It is the circuit diagram which a part of control circuit in the lighting device same as the above was omitted. It is a wave form diagram for operation | movement description of a lighting device same as the above. It is a wave form diagram for operation | movement description of a lighting device same as the above. It is a wave form diagram for operation | movement description of a lighting device same as the above. It is the circuit diagram which abbreviate | omitted partially which shows Embodiment 2 of the lighting device which concerns on this invention. It is the circuit diagram which abbreviate | omitted partially showing Embodiment 3 of the lighting device which concerns on this invention. It is a front view which shows embodiment (Embodiment 4) of the lighting fixture which concerns on this invention. It is the perspective view seen from the back of the lighting fixture same as the above.

  Hereinafter, embodiments of a lighting device and a lighting fixture according to the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
As illustrated in FIG. 1, the lighting device 4 of the present embodiment includes a buck converter 40, a control circuit 41, a first control power supply circuit 42, and a second control power supply circuit 43. Furthermore, the lighting device 4 of the present embodiment preferably includes a PFC circuit 44, a filter circuit 45, a full-wave rectifier 46, a speed-up circuit 47, a PFC driving unit 48, and the like.

  The filter circuit 45 is configured to remove harmonic noise superimposed on an AC voltage / AC current supplied from a commercial AC power supply AC and harmonic noise generated in the PFC circuit 44. The full-wave rectifier 46 is composed of a diode bridge, and full-wave rectifies the AC voltage / AC current supplied from the AC power supply AC. A PFC (Power Factor Correction) circuit 44 is a conventionally known step-up chopper circuit, which converts the pulsating current voltage that has been full-wave rectified by the full-wave rectifier 46 into a desired DC voltage, thereby generating a power factor. Configured to improve. In the PFC circuit 44, an inductor L1, a diode D1, and a smoothing capacitor C1 are electrically connected in series between the pulsating output terminals of the full-wave rectifier 46, and a parallel circuit of two switching elements Q11 and Q12 is smoothed with the diode D1. The capacitor C1 is electrically connected in parallel. The two switching elements Q11 and Q12 are semiconductor switching elements (for example, N-channel power MOSFETs) having common electrical characteristics. That is, the PFC circuit 44 includes a parallel circuit of two switching elements Q11 and Q12, so that the current flowing through the individual switching elements Q11 and Q12 is reduced to suppress the temperature rise. However, the PFC circuit 44 has a conventionally known circuit configuration as disclosed in Patent Document 1 except that the two switching elements Q11 and Q12 are connected in parallel. Detailed description of the operation is omitted. In the following description, the output voltage of the PFC circuit 44 (the voltage across the smoothing capacitor C1) is referred to as a DC input voltage Vdc. Note that the lighting device 4 may be configured to input a DC voltage / DC current supplied from a storage battery or a solar battery to the buck converter 40.

  The buck converter 40 is a switching power supply circuit also called a step-down chopper circuit, and a DC input voltage Vdc of several hundred volts supplied from the PFC circuit 44 is converted into a DC voltage of several tens volts required for a light source (light source unit 1). (Hereinafter referred to as output voltage V1). The buck converter 40 is preferably composed of two switching elements Q21 and Q22, an inductor T1, a diode D4, a smoothing capacitor C3, and the like. The two switching elements Q21 and Q22 are electrically connected in parallel via the inductor T1 between the output terminal on the high potential side of the PFC circuit 44 and the positive electrode of the light source (light source unit 1 described later). The smoothing capacitor C3 is made of an electrolytic capacitor and is electrically connected in parallel with the light source (light source unit 1). The diode D4 has a cathode electrically connected to a connection point between the parallel circuit of the switching elements Q21 and Q22 and the inductor T1, and an anode electrically connected to an output terminal (ground) on the low potential side of the PFC circuit 44. The The two switching elements Q11 and Q12 are semiconductor switching elements (for example, N-channel power MOSFETs) having common electrical characteristics. Further, it is preferable that the detection resistor R8 is electrically connected between the anode of the diode D4 and the low potential side terminal of the smoothing capacitor C3. However, this buck converter 40 has a conventionally well-known circuit configuration as disclosed in Patent Document 1 except that the two switching elements Q21 and Q22 are connected in parallel. Detailed description of the operation is omitted.

  The first control power supply circuit 42 is configured to convert the DC input voltage Vdc of several hundred volts into a DC voltage of tens of volts (for example, 15 volts) (hereinafter referred to as the first control power supply voltage Vcc). The The first control power circuit 42 is preferably composed of a switching power circuit such as a buck converter or a flyback converter.

  Here, the lighting device 4 of the present embodiment includes a bootstrap circuit common to the conventional example described in Patent Document 1. The bootstrap circuit includes a bootstrap diode D2, a bootstrap capacitor C2, and a series circuit of a plurality of resistors R2 to R6 (hereinafter referred to as a resistor series circuit). In the bootstrap diode D2, the first control power supply voltage Vcc is applied to the anode, and one end of the bootstrap capacitor C2 is electrically connected to the cathode. The other end of the bootstrap capacitor C2 is electrically connected to the ground through a resistor series circuit. Further, resistors R3 to R6 are electrically connected in parallel with diode D4 of buck converter 40. As described in Patent Document 1, this bootstrap circuit is configured to charge the bootstrap capacitor C2 with the first control power supply voltage Vcc during the off period of the switching elements Q21 and Q22 of the buck converter 40. . When the bootstrap capacitor C2 is charged, the drive voltage HVcc of the switching elements Q21 and Q22 can be obtained from the high potential side terminal of the bootstrap capacitor C2.

  The second control power circuit 43 is preferably composed of a resistor R7, a diode D3, and a Zener diode ZD1. One end of the resistor R7 is electrically connected to the output terminal on the high potential side of the PFC circuit 44, and the other end of the resistor R7 is electrically connected to the cathode of the Zener diode ZD1 and the anode of the diode D3. The anode of the Zener diode ZD1 is electrically connected to the cathode of the diode D4 of the buck converter 40. The cathode of the diode D3 is electrically connected to the high potential side terminal of the bootstrap capacitor C2. However, the operation of the second control power supply circuit 43 will be described later.

  The control circuit 41 is configured to execute a first control operation for controlling the PFC circuit 44 and a second control operation for controlling the buck converter 40. In addition, it is preferable that such a control circuit 41 is comprised by the integrated circuit which has a circuit which performs 1st control operation, and a circuit which performs 2nd control operation, for example.

  In the first control operation, the control circuit 41 is preferably operated so as to maintain the DC input voltage Vdc at a desired target value (for example, a voltage of about 400 volts). That is, the control circuit 41 measures the DC input voltage Vdc by the resistance voltage dividing circuits R1 and R2, and adjusts the on-duty ratio of the PWM signal so that the DC input voltage Vdc matches the target value based on the measured value. It is preferable to do. This PWM signal is output to the PFC drive unit 48. The PFC drive unit 48 preferably drives the two switching elements Q11 and Q12 on and off simultaneously according to the PWM signal.

  In the second control operation, it is preferable to operate the control circuit 41 so that the current (load current) I1 flowing through the light source (light source unit 1) matches the target value. That is, the control circuit 41 can measure the load current I1 from the voltage across the detection resistor R8, and adjust the on-duty ratio of the PWM signal so that the load current I1 matches the target value based on the measured value. preferable. Note that the control circuit 41 may adjust the target value of the load current I1 in accordance with a dimming signal given from the outside, thereby dimming or turning off the light source (light source unit 1).

  Here, FIG. 2 shows a part (drive circuit) of a circuit configuration for executing the second control operation. The control circuit 41 (drive circuit) preferably includes a series circuit of two switching elements Q31 and Q32, a flip-flop circuit FF, a resistor R16, and a negation circuit (inverter) NOT. The two switching elements Q31 and Q32 are preferably both N-channel MOSFETs, and preferably have the same electrical characteristics. In one switching element Q31, the drive voltage HVcc is applied to the drain, and the source is electrically connected to the drain of the other switching element Q32. The other switching element Q32 has a source electrically connected to a ground terminal HGND having a high level. In the flip-flop circuit FF, a resistor R16 is inserted between the output terminal and the high-level ground terminal HGND, and a negation circuit NOT is inserted between the output terminal and the gate of the other switching element Q32. The gate of one switching element Q31 is electrically connected to the output terminal of the flip-flop circuit FF.

  When the output of the flip-flop circuit FF becomes high level, the high-side switching element Q31 is turned on and the low-side switching element Q32 is turned off. As a result, a drive signal having a voltage substantially equal to the drive voltage HVcc is output from the output terminal Ho of the control circuit 41. On the other hand, when the output of the flip-flop circuit FF becomes low level, the high-side switching element Q31 is turned off and the low-side switching element Q32 is turned on. As a result, the output terminal Ho of the control circuit 41 becomes almost the same potential as the high level ground terminal HGND, and the control circuit 41 stops outputting the drive signal from the output terminal Ho.

  Here, the drive signal of the control circuit 41 is given to the gates of the switching elements Q21 and Q22 via the speed-up circuit 47, respectively. Each speed-up circuit 47 is preferably composed of a PNP bipolar transistor Tr1, a diode D5, resistors R17 to R19, etc. (see FIG. 1). The resistor R17 is electrically connected between the gate and source of each switching element Q21, Q22. The emitter of bipolar transistor Tr1 is electrically connected to the gates of switching elements Q21 and Q22, and the collector of bipolar transistor Tr1 is electrically connected to the sources of switching elements Q21 and Q22 via resistor R18. The base of the bipolar transistor Tr1 is electrically connected to the anode of the diode D5 and one end of the resistor R19, and the other ends of the resistors R19 of each speed-up circuit 47 are electrically connected to the output terminal Ho of the control circuit 41. The

  In each speed-up circuit 47, when a high level drive signal is input from the output terminal Ho, the bipolar transistor Tr1 is turned off, and the drive voltage HVcc is applied between the gate and source of the switching elements Q21 and Q22 via the resistor R17. Apply to turn on. In addition, each speed-up circuit 47 turns on the bipolar transistor Tr1 when the drive signal from the output terminal Ho is stopped, and discharges the charges accumulated in the gates of the switching elements Q21 and Q22 to turn them off. That is, each speed-up circuit 47 is configured to speed up the turn-on of the switching elements Q21 and Q22 made of a power MOSFET.

  The control circuit 41 outputs a high-level drive signal from the output terminal Ho based on the voltage (detection voltage) induced in the detection winding T2 magnetically coupled to the inductor T1 in the second control operation. Is determined. For example, the control circuit 41 is preferably configured to detect a zero cross of a current (inductor current) flowing through the inductor T1 based on the detection voltage and output a drive signal in synchronization with the zero cross.

  By the way, it is preferable that the lighting device 4 of the present embodiment includes a timer circuit. As shown in FIG. 1, the timer circuit is preferably composed of CR integrating circuits of resistors R13 to R15 and a capacitor C4. This timer circuit is configured by connecting a series circuit of resistors R13 to R15 electrically in parallel with a smoothing capacitor C3 and a detection resistor R8, and electrically connecting a low-side resistor R15 and a capacitor C4 in parallel. Since the voltage across the capacitor C4 gradually increases from the time when the AC power supply AC is turned on, the control circuit 41 determines the elapsed time from the time when the capacitor C4 is turned on based on the voltage across the capacitor C4 (hereinafter referred to as a timer signal). Can know. Note that a series circuit of resistors R9 to R12 is preferably electrically connected in parallel to the timer circuit.

  Next, the operation of the lighting device 4 of the present embodiment will be described with reference to the waveform diagrams of FIGS. 3 and 4. 3 and 4 show waveform diagrams of the DC input voltage Vdc, the output voltage V1, the drive voltage HVcc, and the load current I1, respectively.

  First, as shown in FIG. 3, when the AC power supply AC is turned on at time t = t1, the first control power supply circuit 42 is activated to generate the first control power supply voltage Vcc. When the first control power supply voltage Vcc reaches a rated value (for example, 15 volts) (time t = t2), the control circuit 41 is activated to execute the first control operation. Note that the control circuit 41 preferably monitors the elapsed time from the time t = t1 based on the timer signal.

  When the control circuit 41 executes the first control operation, the PFC circuit 44 operates and the DC input voltage Vdc reaches the rated value (time t = t3). When the first control power supply voltage Vcc reaches the rated value, the bootstrap circuit operates normally and a predetermined drive voltage HVcc is applied to the control circuit 41.

  If the control circuit 41 determines that a predetermined time has elapsed since the DC input voltage Vdc reached the rated value based on the timer signal (time t = t4), the control circuit 41 starts the second control operation. When the control circuit 41 starts the second control operation, the output voltage V1 of the buck converter 40 gradually increases, and the load current I1 is changed from the time when the lighting start voltage of the light source (light source unit 1) is exceeded (time t = t5). Start flowing. Then, the control circuit 41 controls (feedback control) the buck converter 40 so that the load current I1 is a constant value. Therefore, the lighting device 4 of this embodiment can light the light source (light source unit 1) with a desired brightness (light output).

  Here, as shown in FIG. 3, it is assumed that an instantaneous power failure occurs in the AC power supply AC at time t = t6. When an instantaneous power failure occurs in the AC power supply AC, the switching elements Q11 and Q12 of the PFC circuit 44 are turned off, and the DC input voltage Vdc is slightly lower than the rated value while the charge accumulated in the smoothing capacitor C1 is being discharged. A low voltage is maintained (see FIG. 3). Therefore, the first control power supply circuit 42 can continue to operate and continue to supply the first control power supply voltage Vcc. However, when the DC input voltage Vdc falls below the rated value, the output voltage V1 of the buck converter 40 drops below the lighting start voltage, so the light source (light source unit 1) is turned off and the load current I1 does not flow. When the PFC circuit 44 is restarted, the DC input voltage Vdc returns to the rated value (time t = t7).

  However, as already described, in the state where the charge charge remains in the smoothing capacitor C3 of the buck converter 40 at the time of restart after an instantaneous power failure, the potential of the high level ground terminal HGND is the first control power supply. It will be maintained in a state higher than the voltage Vcc. As a result, the charging current does not flow from the first control power supply circuit 42 to the bootstrap capacitor C2, and the drive voltage HVcc does not rise to a necessary level, so that the switching elements Q21 and Q22 of the buck converter 40 are not turned on (FIG. 4). reference).

  Therefore, in the lighting device 4 of the present embodiment, the second control power supply circuit 43 generates the drive voltage HVcc only when the bootstrap circuit cannot operate normally (the drive voltage HVcc does not rise to a necessary level). Is configured to do. That is, since the DC input voltage Vdc (≈the peak value of the power supply voltage of the AC power supply AC) exceeds the output voltage V1 of the buck converter 40 during the period of time t = t6 to t7, the second control power supply circuit 43 operates. The bootstrap capacitor C2 is charged. As a result, as shown in FIG. 3, the lighting device 4 of the present embodiment uses the driving voltage HVcc for the switching elements Q21 and Q22 while the PFC circuit 44 is stopped (time t = t6 to t7). The level required for driving can be maintained. However, when the second control power supply circuit 43 causes the charging current to flow through the bootstrap capacitor C2 and the resistor series circuit, the rate at which the DC input voltage Vdc decreases is faster than when the second control power supply circuit 43 does not exist. . Therefore, if the DC input voltage Vdc falls below the output voltage V1 of the buck converter 40 before the PFC circuit 44 restarts and the DC input voltage Vdc exceeds the lighting start voltage, there is a possibility that the buck converter 40 cannot be started. is there. Therefore, the second control power supply circuit 43 must raise the drive voltage HVcc to a necessary voltage within the time from the operation start time of the PFC circuit 44 to the operation start time of the buck converter 40 (time t = t7 to t8). Don't be. In the lighting device 4 of the present embodiment, the second control power circuit 43 needs the drive voltage HVcc by appropriately setting a time constant determined by the combined resistance value of the resistor series circuit and the electrostatic capacitance of the bootstrap capacitor C2. The voltage can be increased up to a certain voltage.

  Here, as shown in FIG. 5, when the PFC circuit 44 is activated (time t = t3, t7), the control circuit 41 overshoots the DC input voltage Vdc, and the bootstrap capacitor C2 by the second control power supply circuit 43 is obtained. The charging time may be shortened. However, in this case, it is preferable that the control circuit 41 protects the circuit elements of the PFC circuit 44 by limiting the overshoot value of the DC input voltage Vdc so as not to be higher than necessary.

  As described above, the lighting device 4 of the present embodiment is a lighting device that lights a light source (light source unit 1) having a solid light emitting element. The lighting device 4 of the present embodiment includes a switching power supply circuit (back converter 40), a drive circuit (a part of the control circuit 41), a control circuit 41, a bootstrap circuit, a first control power supply circuit 42, 2 control power supply circuit 43. The switching power supply circuit has switching elements Q21 and Q22 provided on a higher potential side than the light source, and the DC input voltage Vdc required for the light source by turning on and off the switching elements Q21 and Q22. Configured to convert to The drive circuit is configured to drive the switching elements Q21 and Q22 on and off. The control circuit 41 is configured to control the operation of the switching power supply circuit through the drive circuit. The bootstrap circuit is configured to generate a drive voltage HVcc necessary for the drive circuit to drive the switching elements Q21 and Q22 on and off. The first control power supply circuit 42 is configured to supply power (first control power supply voltage Vcc) to the bootstrap circuit. The second control power supply circuit 43 is configured to generate the drive voltage HVcc only when the bootstrap circuit cannot operate normally.

  The lighting device 4 of the present embodiment is configured as described above, and the drive voltage HVcc can be generated by the second control power circuit 43 even when the bootstrap circuit cannot operate normally. Can be improved. In addition, when the bootstrap circuit can operate normally, the second control power supply circuit 43 does not generate the drive voltage HVcc, so that the power consumption due to both the first control power supply circuit 42 and the second control power supply circuit 43 operating. Can be avoided and the circuit efficiency can be reduced.

  In the lighting device 4 of the present embodiment, the bootstrap circuit preferably includes a bootstrap diode D2, a bootstrap capacitor C2, and current limiting elements R2 to R6. The bootstrap circuit is preferably configured to charge the bootstrap capacitor C2 via the bootstrap diode D2 with the power generated by the first control power circuit 42. Furthermore, the bootstrap circuit is preferably configured to generate the drive voltage HVcc with the charging voltage of the bootstrap capacitor C2. The second control power supply circuit 43 includes a constant voltage element (Zener diode ZD1) that makes the DC input voltage Vdc constant, and a rectifier element (diode D3) that electrically connects the constant voltage element and the bootstrap capacitor C2. It is preferable to have. And it is preferable that the 2nd control power supply circuit 43 is comprised so that the bootstrap capacitor | condenser C2 may be charged with the voltage converted into a constant voltage by the constant voltage element.

  If the lighting device 4 of the present embodiment is configured as described above, the second control power circuit 43 can be realized with a relatively simple configuration, and the reliability can be improved.

  Furthermore, in the lighting device 4 of the present embodiment, the switching power supply circuit is preferably configured as a buck converter 40 that steps down the DC input voltage Vdc. The first control power supply circuit 42 is preferably configured to generate an operation power supply (first control power supply voltage Vcc) for the control circuit 41 and supply the operation power supply to the bootstrap circuit.

  If the lighting device 4 of the present embodiment is configured as described above, the circuit elements can be shared, thereby simplifying the circuit configuration.

  In the lighting device 4 of the present embodiment, the second control power supply circuit 43 is configured to start lighting the light source (light source unit 1) when the voltage across the current limiting elements R3 to R6 of the bootstrap circuit is charged when the bootstrap capacitor C2 is charged. It is preferable to be configured not to exceed the voltage.

  If the lighting device 4 according to the present embodiment is configured as described above, it is possible to suppress a phenomenon in which a slight current flows through the light source (light source unit 1) to emit light (slight emission).

  Furthermore, the lighting device 4 of the present embodiment preferably includes a DC power supply circuit that generates a DC input voltage Vdc from an AC voltage supplied from an external power supply (AC power supply AC). The DC power supply circuit is preferably composed of a non-insulated switching power supply (PFC circuit 44). The second control power supply circuit 43 has both ends of the current limiting elements R3 to R6 of the bootstrap circuit when the bootstrap capacitor C2 is charged when the DC power supply circuit is stopped while an AC voltage is supplied from an external power supply. It is preferable that the voltage is configured not to exceed the lighting start voltage of the light source.

  If the lighting device 4 of the present embodiment is configured as described above, it is possible to suppress the light emission of the light source (light source unit 1).

(Embodiment 2)
Embodiment 2 of the lighting device 4 according to the present invention will be described in detail with reference to FIG. However, the lighting device 4 of the present embodiment has the same basic configuration as the lighting device 4 of the first embodiment. Therefore, the same code | symbol is attached | subjected to the same component as the lighting device 4 of Embodiment 1, and illustration and description are abbreviate | omitted suitably.

  The lighting device 4 of the present embodiment is characterized by the configuration of the second control power supply circuit 43. As shown in FIG. 6, the second control power supply circuit 43 is preferably composed of an NPN bipolar transistor Tr2, a Zener diode ZD1, a diode D3, a capacitor C5, resistors R7, R20, and the like. The collector of the bipolar transistor Tr2 is electrically connected to the output terminal on the high potential side of the PFC circuit 44 via the resistor R20, and the emitter of the bipolar transistor Tr2 is electrically connected to the anode of the diode D3 and one end of the capacitor C5. . The base of the bipolar transistor Tr2 is electrically connected to one end of the resistor R7 and the cathode of the Zener diode ZD1. The other end of the resistor R7 is electrically connected to the output terminal on the high potential side of the PFC circuit 44. The other end of the capacitor C5 and the anode of the Zener diode ZD1 are electrically connected to the cathode of the diode D4 of the buck converter 40. The cathode of the diode D3 is electrically connected to the cathode of the bootstrap diode D2.

  Thus, when the potential of the high level ground terminal HGND is maintained higher than the first control power supply voltage Vcc, the first control power supply circuit 42 cannot charge the bootstrap capacitor C2. On the other hand, even in the above case, the second control power supply circuit 43 can charge the bootstrap capacitor C2 from the bipolar transistor Tr2 via the diode D3. However, when the first control power circuit 42 can normally charge the bootstrap capacitor C2, the second voltage so that the voltage across the capacitor C5 of the second control power circuit 43 is lower than the voltage across the bootstrap capacitor C2. A control power supply circuit 43 is configured. Therefore, when the first control power circuit 42 can normally charge the bootstrap capacitor C2, the second control power circuit 43 does not operate.

  That is, also in the lighting device 4 of the present embodiment, the second control power supply circuit 43 is configured to generate the drive voltage HVcc only when the bootstrap circuit cannot operate normally. In the second control power supply circuit 43 of the present embodiment, if a three-terminal regulator is inserted between the bipolar transistor Tr2 and the diode D3, the second control power supply circuit 43 is hardly affected by temperature characteristics and improves the operational stability. be able to.

  Here, the speed-up circuit 47 in the lighting device 4 of the present embodiment is configured by a conventionally known totem pole drive circuit as shown in FIG. In the speed-up circuit 47, not only the turn-off time of the switching elements Q21 and Q22 but also the turn-on time can be shortened (speeded up). When such a speed-up circuit 47 is used, the drive voltage HVcc can be stabilized by the second control power circuit 43 of this embodiment.

(Embodiment 3)
Embodiment 3 of the lighting device 4 according to the present invention will be described in detail with reference to FIG. However, the lighting device 4 of the present embodiment has the same basic configuration as the lighting device 4 of the second embodiment. Therefore, the same code | symbol is attached | subjected to the same component (including the structure common to Embodiment 1) with the lighting device 4 of Embodiment 2, and illustration and description are abbreviate | omitted suitably.

  The lighting device 4 of this embodiment includes a second control circuit that controls the operation of the second control power supply circuit 43. However, in the lighting device 4 of the present embodiment, it is preferable that the control circuit 41 is also used as the second control circuit.

  As shown in FIG. 7, the control circuit 41 is preferably configured to indirectly measure the voltage across the smoothing capacitor C3 of the buck converter 40 by measuring the voltage across the resistor R12. The control circuit 41 is preferably configured to drive the light emitting diode LD of the photocoupler PC.

  On the other hand, the phototransistor PTr of the photocoupler PC is preferably electrically connected in parallel with the Zener diode ZD1 of the second control power circuit 43.

  Thus, when the power supply of the AC power supply AC is started, the control circuit 41 compares the measured value of the voltage across the smoothing capacitor C3 with a predetermined threshold before operating the buck converter 40. When the measured value is less than the threshold value, the control circuit 41 drives the light emitting diode LD to turn on the phototransistor PTr. When the phototransistor PTr is turned on, both ends of the Zener diode ZD1 are short-circuited by the phototransistor PTr, so that the second control power circuit 43 stops. At this time, since the voltage across the smoothing capacitor C3 has dropped to a sufficiently low voltage, the first control power circuit 42 can charge the bootstrap capacitor C2.

  On the other hand, when the measured value is greater than or equal to the threshold value, the control circuit 41 does not drive the light emitting diode LD and does not turn on the phototransistor PTr. If the phototransistor PTr is not turned on, the second control power circuit 43 operates to charge the bootstrap capacitor C2.

  That is, in the lighting device 4 of the present embodiment, the control circuit 41 normally charges the bootstrap capacitor C2 in the first control power supply circuit 42, and attaches the bootstrap capacitor C2 to the second control power supply circuit 43 only when necessary. It is configured to be charged. That is, the first control power circuit 42 is superior to the second control power circuit 43 in terms of performance such as operation stability and circuit efficiency. Therefore, the drive voltage HVcc can be stabilized by the first control power supply circuit 42 charging the bootstrap capacitor C2 except in special cases such as at the time of restart.

  As described above, the lighting device 4 of the present embodiment preferably includes the second control circuit (control circuit 41) that controls the operation of the second control power supply circuit 43. The second control circuit measures the voltage between the output terminals of the switching power supply circuit (buck converter 40) (the voltage across the smoothing capacitor C3) when the power supply of the external power supply (AC power supply AC) is started. Preferably, it is configured. Further, it is preferable that the second control circuit is configured not to cause the second control power supply circuit 43 to generate the drive voltage HVcc when the voltage between the output terminals is less than a predetermined threshold value. The second control circuit is preferably configured to cause the second control power supply circuit 43 to generate the drive voltage HVcc when the voltage between the output terminals is equal to or higher than the threshold value.

  If the lighting device 4 of the present embodiment is configured as described above, the drive voltage HVcc can be stabilized.

(Embodiment 4)
Next, an embodiment of a lighting fixture according to the present invention will be described with reference to FIGS. In the present embodiment, a projector is exemplified as the lighting fixture. However, the lighting fixture to which the technical idea of the present invention can be applied is not limited to the projector, and for example, a lighting fixture for a high ceiling or a road lamp may be used.

  As illustrated in FIGS. 8 and 9, the lighting fixture of the present embodiment includes a plurality (four in the illustrated example) of light source units 1 and a lighting device 4 that lights the plurality of light source units 1. Furthermore, the lighting fixture of the present embodiment preferably includes a connecting member that connects the plurality of light source units 1 and the arm 16. However, the number of light source units 1 constituting the lighting fixture is not limited to four, and may be one to three, or five or more. In the following description, unless otherwise specified, the vertical, horizontal, and front-rear directions are defined in FIG. 8 and the front side of the page is the front.

  The light source unit 1 includes an LED module and a heat radiating member 3. The LED module preferably includes a plurality of light emitting diodes (LEDs) and a mounting substrate. The LED is, for example, a conventionally known package type white LED. However, an organic electroluminescence (EL) element may be used instead of the LED. The mounting substrate is preferably composed of a rectangular flat plate-like aluminum substrate. The LEDs are mounted side by side vertically and horizontally on the front surface of the mounting substrate. A receptacle connector is mounted on the front surface of the mounting board. The receptacle connector is electrically connected to the electrodes (cathode and anode) of each LED via a wiring conductor formed on the front surface of the mounting substrate.

  The heat radiating member 3 is preferably composed of a base portion 30, a pair of edge portions 31, and a plurality of heat radiating plates 32. In addition, it is preferable that the base part 30, the edge part 31, and the heat sink 32 are formed with the material excellent in thermal conductivity, such as aluminum alloy, for example. The base part 30 is formed in a rectangular flat plate shape. The LED module is fixed to the front surface of the base unit 30. Further, the cover 7 is attached to the front surface of the base portion 30 so as to cover the LED module (see FIG. 8). The cover 7 is formed in a flat rectangular box shape using a synthetic resin material having translucency such as polycarbonate resin. The pair of edge portions 31 have a rectangular parallelepiped shape whose longitudinal direction is the vertical direction, and are formed integrally with the base portion 30 at the left end edge and the right end edge of the base portion 30. In addition, the thickness (width in the front-rear direction) of the edge portion 31 is formed sufficiently larger than the thickness of the base portion 30.

  The connecting member preferably includes a first connecting member 10, a second connecting member 11, a third connecting member 12, and an auxiliary connecting member.

  The first connecting member 10 includes a strip-shaped main piece 100 and an auxiliary piece 101 that protrudes in the thickness direction of the main piece 100 along the longitudinal direction of the main piece 100. The main piece 100 and the auxiliary piece 101 are integrally formed by bending a metal plate such as a stainless steel plate along the longitudinal direction.

  The first connecting member 10 is provided with projecting pieces 102 and 103 at both ends and the center in the longitudinal direction of the main piece 100, respectively. However, the central projecting piece 103 has a length dimension almost twice that of the projecting pieces 102 at both ends. Further, the tip of the central projecting piece 103 is bent outward. Each of the projecting pieces 102 and 103 is provided with one or two screw insertion holes.

  As shown in FIG. 9, the first connecting member 10 is attached to the two light source units 1 by screwing the projecting pieces 102 and 103 to the edge 31 of the heat radiating member 3. That is, the screw 104 inserted into the screw insertion hole of each of the projecting pieces 102 and 103 is screwed into the screw hole of the edge portion 31.

  The 2nd connection member 11 is comprised with a strip | belt-shaped metal plate (for example, stainless steel plate etc.). However, the central portion 110 of the second connecting member 11 protrudes in the thickness direction with respect to the end portions 111 on both sides. The central portion 110 is provided with three screw insertion holes. On the other hand, each end portion 111 is provided with two screw insertion holes (see FIG. 9).

  The second connecting member 11 is attached to the two light source units 1 by being screwed to the edge 31 of the heat radiating member 3. That is, the screw 112 inserted through the screw insertion hole of the center part 110 and each end part 111 is screwed into the screw hole of the edge part 31 (see FIG. 9).

  The 3rd connection member 12 is comprised with a strip | belt-shaped metal plate (for example, stainless steel plate etc.). However, the third connecting member 12 is reinforced by bending both end portions along the longitudinal direction in the thickness direction. The third connecting member 12 is provided with two screw insertion holes at both ends in the longitudinal direction. These screw insertion holes are provided so as to be aligned in the short direction of the third connecting member 12. The 3rd connection member 12 is attached to the four light source units 1 by screwing to the edge part 31 of the thermal radiation member 3 (refer FIG. 8).

  The auxiliary connecting member includes a pair of arm attachment members 13 and a pair of reinforcing members 14. The arm attachment member 13 includes a square hook-shaped fixing part 130, a pair of attachment parts 131, and a bearing part 132. In addition, it is preferable that the fixing | fixed part 130, the attaching part 131, and the bearing part 132 are integrally formed by aluminum die casting, for example.

  The pair of attachment portions 131 are formed in a long truncated cone shape and protrude rearward from the fixed portion 130. A female thread is formed at the tip of each mounting portion 131.

  The bearing portion 132 is formed in a cylindrical shape, is disposed between the pair of attachment portions 131, and is connected to each attachment portion 131 and the fixing portion 130. A screw hole is provided at the center of the bearing portion 132.

  As shown in FIG. 9, the reinforcing member 14 is formed of a band-shaped metal plate (for example, a stainless steel plate). However, the reinforcing member 14 is reinforced by bending both end portions along the longitudinal direction in the thickness direction. The pair of reinforcement members 14 are attached to the attachment portions 131 of the arm attachment members 13 on the left and right sides so as to be aligned in the vertical direction. That is, the bolt 140 is inserted into the screw insertion holes provided at both ends of the reinforcing member 14, and the bolt 140 is screwed into the female screw at the distal end portion of the attachment portion 131 (see FIG. 9).

  As shown in FIG. 9, the arm 16 includes a fixed plate 160, a pair of rising pieces 161 that rise obliquely upward from the left and right ends of the fixed plate 160, and a support piece 162 that rises diagonally upward from the tip of each rising piece 161. Are integrally formed of a metal plate.

  In the fixing plate 160, a circular fixing hole 1601 passes through substantially the center, and a semicircular arc-shaped long hole 1600 centering on the fixing hole 1601 passes behind the fixing hole 1601 (see FIG. 9). Then, the fixing plate 160 is fixed to an illumination stand (concrete base) or the like by a bolt inserted through the fixing hole 1601 and a bolt inserted through the long hole 1600. Further, by loosening the bolt inserted through the long hole 1600, the direction of the arm 16 (the direction of the light source unit 1) can be changed within a range of about 180 degrees.

  Each support piece 162 has a circular insertion hole passing through the tip. Therefore, the bolt 163 inserted through the insertion hole is screwed into the screw hole of the bearing portion 132 of the arm attachment member 13, so that the four light source units 1 connected by the connection member can be rotatably supported by the arm 16. it can.

  By the way, the wiring box 15 is attached to the lower reinforcing member 14 by screwing (see FIG. 9).

  The wiring box 15 is formed in a rectangular box shape by a metal material. A relay terminal block is accommodated in the wiring box 15. The terminal block is configured to electrically connect a power cable for supplying AC power from the power system and a power cable 9 for supplying AC power to the lighting device 4.

  It is preferable that the lighting device 4 includes a metal case 81. The case 81 preferably includes a case body 82 and two lids 83 and 84 (see FIG. 9). The case main body 82 is preferably formed in a rectangular tube shape with both ends in the axial direction opened by, for example, extrusion molding of aluminum or an aluminum alloy. Further, four cable insertion holes pass through the lower end portion of the side wall in front of the case main body 82. An output cable is inserted through each of the four cable insertion holes, and the output cable is fixed to the side wall by a stopper.

  The lid portions 83 and 84 are preferably formed in a flat plate shape by aluminum die casting, for example. These two lid portions 83 and 84 are preferably configured so as to close the openings at both ends of the case main body 82 by being screwed to the end portions in the axial direction of the case main body 82 (see FIG. 9). ). However, it is preferable that waterproof packing is sandwiched between the lids 83 and 84 and the end of the case body 82 to prevent rainwater from entering the case body 82. Moreover, the cable insertion hole has penetrated the center of the cover part 84 of one side (front). Then, the power cable 9 is inserted into the cable insertion hole, and the power cable 9 is fixed to the lid portion 84 with a stopper.

  As for the lighting device 4, as shown in FIG. 9, it is preferable that the side wall of the case main body 82 is screwed to the pair of reinforcing members 14. At this time, it is preferable that the lighting device 4 is fixed to the reinforcing member 14 in such a posture that the lid portion 84 to which the power cable 9 is fixed is down and the other lid portion 83 is up.

  By the way, when the lighting fixture of this embodiment is installed in a lighting stand, it is preferable that the both ends of the metal wires 17 are screwed to the center part 110 of the 2nd connection member 11, respectively (refer FIG. 9). Furthermore, it is preferable that the wire 17 is supported by a wire receiver 18 fixed to the illumination table (see FIG. 9). In other words, when the arm 16 is detached from the illumination table, the wire 17 supports the fall of the lighting fixture.

  As described above, the lighting fixture of the present embodiment includes the lighting device 4 of any one of the first to third embodiments and the light source (light source unit 1) that is turned on by the lighting device 4.

  Moreover, in the lighting fixture of this embodiment, it is preferable that a light source (light source unit 1) has a light emitting diode or an organic electroluminescent element as a solid light emitting element.

  Since the lighting fixture of this embodiment is comprised as mentioned above, the improvement of the stability of the operation | movement at the time of restart can be aimed at.

1 Light source unit (light source)
4 Lighting device 40 Buck converter (switching power supply circuit)
41 Control circuit (control circuit, drive circuit and second control circuit)
42 1st control power supply circuit 43 2nd control power supply circuit 44 PFC circuit Q21, Q22 Switching element D2 Bootstrap diode C2 Bootstrap capacitor R2-R6 Resistance (current limiting element)
ZD1 Zener diode (constant voltage element)
D3 Diode (rectifier element)

Claims (8)

  A lighting device for lighting a light source having a solid state light emitting element, including a switching element provided on a higher potential side than the light source, and a DC input voltage required for the light source by driving the switching element on and off A switching power supply circuit for converting to a DC voltage, a drive circuit for driving the switching element on and off, a control circuit for controlling the operation of the switching power supply circuit through the drive circuit, and the drive circuit for turning on and off the switching element A bootstrap circuit that generates a drive voltage necessary for driving, a first control power supply circuit that supplies power to the bootstrap circuit, and the drive voltage only when the bootstrap circuit cannot operate normally And a second control power supply circuit for generating the lighting device. The bootstrap circuit includes a bootstrap diode, a bootstrap capacitor, and a current limiting element, and the power supply generated by the first control power supply circuit causes the bootstrap capacitor to pass through the bootstrap diode. Charging and generating the drive voltage with a charge voltage of the bootstrap capacitor;
The second control power supply circuit includes a constant voltage element that makes the DC input voltage constant, and a rectifier element that electrically connects the constant voltage element and the bootstrap capacitor. The lighting device according to claim 1, wherein the bootstrap capacitor is configured to be charged with a constant voltage.   The switching power supply circuit is configured as a buck converter that steps down the DC input voltage, the first control power supply circuit generates an operation power supply for the control circuit, and the operation power supply is used as the bootstrap circuit. The lighting device according to claim 1, wherein the lighting device is configured to be supplied.   The second control power supply circuit is configured so that a voltage across the current limiting element of the bootstrap circuit does not exceed a lighting start voltage of the light source when the bootstrap capacitor is charged. 2. The lighting device according to 2.   A DC power supply circuit that generates the DC input voltage from an AC voltage supplied from an external power supply; the DC power supply circuit is configured by a non-insulated switching power supply; and the second control power supply circuit is configured by the external power supply. When the DC power supply circuit is stopped in a state where the AC voltage is supplied from, the voltage across the current limiting element of the bootstrap circuit becomes the lighting start voltage of the light source when the bootstrap capacitor is charged. The lighting device according to claim 4, wherein the lighting device is configured not to exceed.   A second control circuit for controlling the operation of the second control power supply circuit; the second control circuit has a predetermined voltage between the output terminals of the switching power supply circuit when power supply to the external power supply is started; The drive voltage is not generated in the second control power supply circuit when the threshold voltage is less than the threshold value, and the drive voltage is generated in the second control power supply circuit when the voltage between the output terminals is equal to or higher than the threshold It is comprised so that it may make it. The lighting device of any one of Claims 1-5 characterized by the above-mentioned.   A lighting apparatus comprising: the lighting device according to claim 1; and the light source that is turned on by the lighting device.   The lighting apparatus according to claim 7, wherein the light source includes a light emitting diode or an organic electroluminescence element as the solid state light emitting element.

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