JP2017033626A - Lighting device and luminaire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device 2 and a luminaire 1 that can perform lighting control at a low dimming level, enhance responsibility and secure synchronization among luminaires.SOLUTION: A lighting device 2 includes a plurality of lighting circuit units for applying a DC input voltage to an LED load and supplying load current to the LED load. The lighting device 2 further includes a control circuit unit 4 for controlling the operation of the plurality of lighting circuit units based on an instructed dimming level (dimming instruction value) to increase or reduce the amplitude of the load current. The control circuit unit 4 sets a plurality of dimming ranges between a dimming lower limit value OL and a dimming upper limit value OU and associates at least one lighting circuit unit with each of the plurality of dimming ranges. A luminaire 1 includes a lighting device 2 and a plurality of LED loads. Each of the LED loads is connected to the lighting circuit unit on a one-to-one basis.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lighting device and a lighting fixture, and more particularly, to a lighting device that lights an LED (Light Emitting Diode) and a lighting fixture including the lighting device.

  As a conventional example, an LED lighting circuit described in Patent Document 1 is illustrated. The LED lighting circuit described in Patent Document 1 includes an AC power supply as an input power supply, and includes a diode bridge, two step-down chopper circuits, and a dimming control unit. The diode bridge rectifies an AC voltage input from an AC power source, and generates a rectified voltage at both ends of a capacitor composed of an electrolytic capacitor provided between output terminals. The two step-down chopper circuits are connected in parallel to each other, connected to both ends of the capacitor, and applied with a rectified voltage. The step-down chopper circuit steps down the rectified voltage to generate a DC voltage. And a direct current voltage is applied to the LED light source part which consists of the light emitting diode connected to each step-down chopper circuit, LED current flows into an LED light source part, and an LED light source part lights.

  The dimming control unit is configured by a microcomputer or the like, and outputs a transmission control signal to the oscillation control unit provided in the step-down chopper circuit based on the dimming degree indicated by the dimming signal output from the dimming signal output unit. . The oscillation control signal is composed of a PWM signal. The oscillation control unit controls oscillation of the switching element provided in the step-down chopper circuit based on the oscillation control signal.

JP2011-192399A

  By the way, in the conventional LED lighting circuit, when the LED light source unit is lit at a low dimming level, the LED light source unit is lit by burst dimming. In the burst dimming, the brightness of the LED is controlled by intermittently interrupting the load current supplied to the LED light source unit and adjusting the on-duty for supplying the load current to the LED. When the LED light source unit is turned on using burst dimming, flickering and video flicker occur in the conventional LED lighting circuit when the LED light source unit is turned on with a low dimming level, that is, with a long off time. End up. In a conventional LED lighting circuit, a large-capacity electrolytic capacitor for smoothing the voltage applied to the LED light source unit is used, so that the current flowing through the LED light source unit flows continuously, and flicker and video flicker are prevented. Can be suppressed. However, in a conventional LED lighting circuit, it is difficult to ensure responsiveness and synchronism between instruments because a large-capacity electrolytic capacitor is used.

  The present invention has been made in view of the above-described reasons, and provides a lighting device and a lighting fixture that can be dimmed to a low dimming level and can improve responsivity and ensure synchronism between fixtures. For the purpose.

The lighting device of the present invention includes a plurality of lighting circuit units that apply a voltage obtained by stepping down a DC input voltage to an LED load and supply a load current to the LED load, and the plurality of lightings based on an instructed dimming level. A control circuit unit that controls the operation of the circuit unit and increases or decreases the amplitude of the load current, the control circuit unit sets a plurality of dimming ranges between the dimming lower limit value and the dimming upper limit value, Associating at least one lighting circuit unit with each of a plurality of dimming ranges, and controlling the lighting circuit unit associated with the dimming range to which the instructed dimming level belongs, to the LED load A load current is supplied.

  The lighting fixture of the present invention includes the above-described lighting device and a plurality of LED loads, each of the LED loads including one to a plurality of light-emitting diodes, and electrically connected to the lighting circuit unit on a one-to-one basis. It is characterized by.

  The lighting device and the lighting fixture of the present invention can be dimmed to a low dimming level, and there is an effect that the responsiveness can be improved and the synchronization between the fixtures can be ensured.

It is a circuit block diagram which shows the lighting fixture which concerns on embodiment. It is explanatory drawing explaining the light control level of the light source part corresponding to the light control instruction value in the lighting device which concerns on embodiment. FIG. 3A is an explanatory diagram illustrating each dimming level of a lighting circuit unit corresponding to a dimming instruction value, and FIG. 3B is an enlarged view of an essential part of FIG. 3A. The lighting fixture which concerns on embodiment is shown, FIG. 4A is a schematic structure figure of a stand-alone type, FIG. 4B is a schematic structure figure of an integral type. It is a block diagram which shows the principal part of the lighting fixture which concerns on embodiment. It is a circuit block diagram which concerns on the stand-alone type lighting fixture shown by FIG. 4A.

  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. In embodiment described below, the lighting fixture 1 installed in the ceiling 100 (refer FIG. 4A) is illustrated. However, the technical idea of the present invention can also be applied to a lighting fixture installed in a place other than the ceiling 100.

  As illustrated in FIG. 1, the lighting fixture 1 of the present embodiment includes a first LED load 61 including one to a plurality of light emitting diodes (LEDs) 611 and a second LED including one to a plurality of light emitting diodes 621. A light source unit 10 having a load 62 is provided. The lighting fixture 1 further includes a lighting device 2 that supplies a first load current I1 and a second load current I2 to the first LED load 61 and the second LED load 62, respectively.

  The lighting device 2 includes a first lighting circuit unit 31 that supplies a first load current I1 to the first LED load 61, and a second lighting circuit unit 32 that supplies a second load current I2 to the second LED load 62. The lighting device 2 controls the operation of the first lighting circuit unit 31 and the second lighting circuit unit 32 based on the instructed dimming level (hereinafter referred to as dimming instruction value), and the first load current I1 and the first load current I1. A control circuit unit 4 that increases or decreases the amplitude of each of the two load currents I2 is further provided. The lighting device 2 further includes a power supply circuit unit 5 that supplies DC power to the first lighting circuit unit 31 and the second lighting circuit unit 32.

  The power supply circuit unit 5 includes a filter circuit 51, a rectifier circuit 52, a PFC circuit (power factor correction circuit) 53, and a smoothing circuit 54.

  The filter circuit 51 includes, for example, a capacitor, an inductor, and a resistor, and removes a noise component of AC power supplied from an external input power supply (commercial power supply 70). The rectifier circuit 52 is a diode bridge, and full-wave rectifies the power output from the filter circuit 51. The power factor correction circuit 53 averages high frequency components present in the current output from the rectifier circuit 52 by an inductor or the like. The smoothing circuit 54 is a capacitor, for example, and smoothes the voltage output from the power factor correction circuit 53.

  The first lighting circuit unit 31 is a step-down chopper circuit configured by a first switching element Q1, a first diode D1, a first inductor L1, a first detection resistor R1, a first capacitor C1, and the like. The first switching element Q1 is an n-channel power MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). The drain of the first switching element Q1 is electrically connected to the anode of the first diode D1, and the source of the first switching element Q1 is electrically connected to the negative electrode of the power supply circuit unit 5 via the first detection resistor R1. Has been. One end of the first inductor L1 is electrically connected to a connection point between the anode of the first diode D1 and the drain of the first switching element Q1. The other end of the first inductor L1 is electrically connected to one end of the first capacitor C1. The other end of the first capacitor C1 is electrically connected to the cathode of the first diode D1. The first LED load 61 is electrically connected in parallel to the first capacitor C1. Note that the gate of the first switching element Q1 is electrically connected to the control circuit unit 4. The first lighting circuit unit 31 uses the DC power output from the power supply circuit unit 5 as input power, and the first switching element Q1 is turned on and off to supply the first load current I1 to the first LED load 61 to thereby supply the first LED. The load 61 is turned on.

  The second lighting circuit unit 32 is a step-down chopper circuit that includes a second switching element Q2, a second diode D2, a second inductor L2, a second detection resistor R2, a second capacitor C2, and the like. The second switching element Q2 is an n-channel type power MOSFET, the drain is electrically connected to the anode of the second diode D2, and the source of the second switching element Q2 is connected to the power supply circuit via the second detection resistor R2. It is electrically connected to the negative electrode of the part 5. One end of the second inductor L2 is electrically connected to a connection point between the anode of the second diode D2 and the drain of the second switching element Q2. The other end of the second inductor L2 is electrically connected to one end of the second capacitor C2. The other end of the second capacitor C2 is electrically connected to the cathode of the second diode D2. The second LED load 62 is electrically connected in parallel to the second capacitor C2. The gate of the second switching element Q2 is electrically connected to the control circuit unit 4. The second lighting circuit unit 32 uses the direct current power output from the power supply circuit unit 5 as input power, and the second switching element Q2 is turned on and off to supply the second load current I2 to the second LED load 62 to thereby supply the second LED. The load 62 is turned on.

  The control circuit unit 4 includes a dimming control unit 41, a first drive circuit 42, and a second drive circuit 43. The control circuit unit 4 controls the first load current I1 and the second load current I2 by controlling on / off of the first switching element Q1 and the second switching element Q2, and the first lighting circuit unit 31 and the second The lighting circuit unit 32 is operated. The control circuit unit 4 increases or decreases the amplitudes of the first load current I1 and the second load current I2, and continuously performs DC dimming to be supplied to the first LED load 61 and the second LED load 62, thereby causing the first lighting circuit. The unit 31 and the second lighting circuit unit 32 are controlled. Therefore, the first capacitor C1 and the second capacitor C2 do not need to be large-capacity electrolytic capacitors, and may be small-capacitance capacitors such as film capacitors.

  The dimming control unit 41 is, for example, a microcomputer having a storage unit, and is electrically connected to the first drive circuit 42 and the second drive circuit 43. The dimming control unit 41 outputs a dimming signal (PWM signal) (Pulse Width Modulation) to the first drive circuit 42 and the second drive circuit 43 based on the dimming instruction value. The dimming instruction value is a signal input from an external device such as a remote controller.

  In addition, the dimming control unit 41 monitors the first detection voltage Va (detected value of the first load current I1) that is the voltage across the first detection resistor R1 during the ON period of the first switching element Q1. Further, the dimming control unit 41 monitors the second detection voltage Vb (detected value of the second load current I2) that is the voltage across the second detection resistor R2 during the ON period of the second switching element Q2. The dimming control unit 41 sets a first upper limit value and a second upper limit value to be compared with each of the first detection voltage Va and the second detection voltage Vb. Furthermore, the dimming control unit 41 sets a desired first driving cycle and second driving cycle, and adjusts the on-duty (on period) to adjust the dimming levels of the first LED load 61 and the second LED load 62, respectively. To change.

  The first drive circuit 42 is electrically connected to the gate of the first switching element Q1. When the PWM signal that alternately repeats the Hi level and the Lo level output from the dimming control unit 41 is input to the first drive circuit 42, the drive signal necessary for driving the first switching element Q1 is first switched. Input to the gate of the element Q1.

  The second drive circuit 43 is electrically connected to the gate of the second switching element Q2. When the PWM signal that alternately repeats the Hi level and the Lo level output from the dimming control unit 41 is input to the second drive circuit 43, the drive signal necessary for driving the second switching element Q2 is second switched. Input to the gate of the element Q2.

  By the way, as shown in FIG. 2, the dimming control unit 41 corresponds to the dimming level 100% from the dimming lower limit value OL of the dimming instruction value corresponding to the dimming level 0.25% of the light source unit 10. The first dimming threshold value OT1 is set in the dimming range up to the dimming upper limit value OU of the dimming instruction value. The light control level of the light source unit 10 is the total light control level of the light control level of the first LED load 61 and the light control level of the second LED load 62. Further, the dimming control unit 41 sets the second dimming threshold OT2 in a dimming range that is lower than the dimming upper limit value OU of the dimming instruction value and is equal to or greater than the first dimming threshold OT1. A dimming range that is equal to or smaller than the dimming upper limit OU and equal to or greater than the first dimming threshold OT1 is defined as a first dimming range OR1, and a dimming range that is equal to or greater than the dimming lower limit OL and equal to or smaller than the second dimming threshold OT2. The second dimming range OR2.

  The second dimming range OR2 corresponds to a dimming level lower than the first dimming range OR1. In the lighting device 2 of the present embodiment, the first dimming range OR1 is a range of the dimming level from 5% to 100%. The second dimming range OR2 is a range where the dimming level is 0.25% to 6%.

  The operation of the lighting device 2 of the present embodiment will be described with reference to FIGS. 1 and 2. The solid line shown in FIG. 2 is the light control level of the light source unit 10 corresponding to the light control instruction value.

  When the dimming instruction value is within the first dimming range OR1, the control circuit unit 4 controls the first lighting circuit unit 31 to supply the first load current I1 to the first LED load 61. When the dimming instruction value is within the second dimming range OR2, the control circuit unit 4 controls the second lighting circuit unit 32 to supply the second load current I2 to the second LED load 62.

  The second lighting circuit unit 32 is configured to supply the second load current I2 to the second LED load 62 based on the low dimming instruction value. That is, the second load current I2 flowing through the second LED load 62 is smaller than the first load current I1 flowing through the first LED load 61. Therefore, by making the resistance value of the second detection resistor R2 larger than the resistance value of the first detection resistor R1, the dimming control unit 41 can detect the second detection voltage Vb in a wider range. Thereby, the control circuit unit 4 can control the second load current I2 with high accuracy.

  First, the case where the 1st LED load 61 lights in the dimming range of 1st dimming range OR1 is demonstrated.

  When a Hi level signal is input from the dimming control unit 41 based on the dimming instruction value, the first driving circuit 42 inputs a Hi level driving signal to the gate of the first switching element Q1. When the first switching element Q1 is turned on, a current flows through a path of the first LED load 61 → the first inductor L1 → the first switching element Q1 → the first detection resistor R1, and the first load current I1 increases.

  As the first load current I1 increases, the voltage across the first detection resistor R1, that is, the first detection voltage Va also increases. When the first detection voltage Va reaches the first upper limit value, the dimming control unit 41 inputs the Lo level PWM signal to the first drive circuit 42. When receiving the Lo level signal from the dimming control unit 41, the first drive circuit 42 inputs the Lo level drive signal to the gate of the first switching element Q1. Then, the first switching element Q1 is switched from the on state to the off state.

  When the first switching element Q1 is switched to the OFF state, a regenerative current flows in a closed circuit of the first diode D1 → the first LED load 61 → the first inductor L1 due to the energy stored in the first inductor L1. Then, the first load current I1, that is, the current flowing through the first inductor L1, gradually decreases. When the first driving cycle in which the OFF state of the first switching element Q1 is set in the dimming control unit 41 elapses, the dimming control unit 41 re-inputs the Hi level PWM signal to the first driving circuit 42. The 1 switching element Q1 is switched from the off state to the on state.

  By repeating these series of operations (on / off of the first switching element Q1), the on / off driving of the first switching element Q1 is executed, the first lighting circuit unit 31 is driven, and based on the dimming instruction value The first load LED 61 is lit.

  Next, the case where the 2nd LED load 62 lights in the dimming range of 2nd dimming range OR2 is demonstrated.

  When a Hi level signal is input from the dimming control unit 41 based on the dimming instruction value, the second driving circuit 43 inputs a Hi level driving signal to the gate of the second switching element Q2. When the second switching element Q2 is turned on, a current flows through the path of the second LED load 62 → the second inductor L2 → the second switching element Q2 → the second detection resistor R2, and the second load current I2 increases.

  As the second load current I2 increases, the voltage across the second detection resistor R2, that is, the second detection voltage Vb also increases. When the second detection voltage Vb reaches the second upper limit value, the dimming control unit 41 inputs the Lo level PWM signal to the second drive circuit 43. When receiving the Lo level signal from the dimming control unit 41, the second drive circuit 43 inputs the Lo level drive signal to the gate of the second switching element Q2. Then, the second switching element Q2 is switched from the on state to the off state.

  When the second switching element Q2 is switched to the OFF state, a regenerative current flows in a closed circuit of the second diode D2 → the second LED load 62 → the second inductor L2 due to the energy stored in the second inductor L2. Then, the second load current I2, that is, the current flowing through the second inductor L2 gradually decreases. When the second driving cycle in which the second switching element Q2 is turned off passes the second driving cycle set in the dimming control unit 41, the dimming control unit 41 re-inputs the Hi level PWM signal to the second driving circuit 43. The two switching element Q2 is switched from the off state to the on state.

  By repeating these series of operations (on / off of the second switching element Q2), the on / off driving of the second switching element Q2 is executed, the second lighting circuit unit 32 is driven, and based on the dimming instruction value The second load LED 62 is lit.

  In the lighting device 2 of the present embodiment, since the first lighting circuit unit 31 and the second lighting circuit unit 32 perform DC dimming, a large-capacity capacitor is used as the first capacitor C1 and the second capacitor C2 between the output terminals. There is no need to do. Therefore, since the lighting device 2 can perform low dimming by DC dimming, the responsiveness can be improved and the synchronism between the instruments can be ensured regardless of the dimming level. Further, in the lighting device 2, by adjusting the resistance value of the second detection resistor R <b> 2 to be larger than the resistance value of the first detection resistor R <b> 1, accurate light control is possible even with a low light control instruction value. .

  By the way, in order to avoid that both the 1st LED load 61 and the 2nd LED load 62 turn off simultaneously, as shown to FIG. 3A and 3B, the lighting device 2 is 1st dimming threshold value OT1 and 2nd dimming. A heavy lighting section OR12 that is a dimming range between the threshold values OT2 is provided. The control circuit unit 4 controls the first lighting circuit unit 31 and the second lighting circuit unit 32 so that both the first LED load 61 and the second LED load 62 are lit in the heavy lighting section OR12.

  Here, a case where the dimming instruction value is set in the heavy lighting section OR12 will be described. In FIG. 3A and FIG. 3B, the line represented by a solid line is the dimming level of the first LED load 61 corresponding to the dimming instruction value, and the line represented by a broken line is the second LED corresponding to the dimming instruction value. The dimming level of the load 62.

  First, a case where the dimming instruction value moves (changes) from a value higher than the second dimming threshold value OT2 to a value lower than the first dimming threshold value OT1 will be described. In the following description, the dimming level Xa%, the dimming level Xb%, and the dimming level Xc% will be defined and described (see FIG. 3B). The dimming level Xc% is a value set between the dimming level 5% and 6%. The dimming level Xa% and the dimming level Xb% are values set between 0.25% and 5% of the dimming level. Furthermore, the light control level Xa% is a value lower than the light control level Xb%.

  However, the shift of the dimming level and the dimming level of the first LED load 61 and the dimming level of the second LED load 62 in the heavy lighting section OR12 described below are examples and are not limited to the present embodiment. Absent.

  When the dimming instruction value is higher than the second dimming threshold value OT2, the control circuit unit 4 supplies the first load current I1 based on the dimming instruction value to the first LED load 61 so as to be supplied. Drive. Further, the control circuit unit 4 controls the second lighting circuit unit 32 so that the dimming level of the second LED load 62 becomes 0%.

  When the dimming instruction value reaches the second dimming threshold value OT2 (dimming level 6%), the control circuit unit 4 reduces the dimming level of the first LED load 61 from 6% to Xc%, and the first LED load The first lighting circuit unit 31 is driven so that 61 lights up at the dimming level Xc%. At this time, the control circuit unit 4 increases the dimming level of the second LED load 62 from 0% to Xa%, and drives the second lighting circuit unit 32 so that the second LED load 62 lights up at the dimming level Xa%. To do.

  Then, as the dimming instruction value becomes lower, the control circuit unit 4 drives the first lighting circuit unit 31 so as to gradually lower the dimming level of the first LED load 61. Further, as the dimming instruction value decreases, the control circuit unit 4 drives the second lighting circuit unit 32 so as to gradually increase the dimming level of the second LED load 62.

  When the dimming instruction value reaches the first dimming threshold value OT1 (dimming level 5%), the control circuit unit 4 reduces the dimming level of the first LED load 61 from Xb% to 0%, and the first LED load The first lighting circuit unit 31 is controlled so that the dimming level of 61 becomes 0%. Further, the control circuit unit 4 increases the dimming level of the second LED load 62 from Xb% to 5%, and drives the second lighting circuit unit 32 so that the second LED load 62 lights up at the dimming level of 5%. .

  In the heavy lighting section OR12, the control circuit unit 4 controls the first dimming level so that the sum of the dimming level of the first LED load 61 and the dimming level of the second LED load 62 becomes the dimming level corresponding to the dimming instruction value. The lighting circuit unit 31 and the second lighting circuit unit 32 are controlled.

  When the dimming instruction value is lower than the first dimming threshold value OT1, the control circuit unit 4 controls the first lighting circuit unit 31 so that the dimming level of the first LED load 61 becomes 0%, and the second LED load 62 Drives the second lighting circuit unit 32 so that the second load current I2 based on the dimming instruction value is supplied.

  Next, a case where the dimming instruction value moves (changes) from a value lower than the first dimming threshold OT1 to a value higher than the second dimming threshold OT2 will be described.

  When the dimming instruction value is lower than the first dimming threshold value OT1, the control circuit unit 4 supplies the second load current I2 based on the dimming instruction value to the second LED load 62 so that the second lighting circuit unit 32 is supplied. Drive. Further, the control circuit unit 4 controls the first lighting circuit unit 31 so that the dimming level of the first LED load 61 becomes 0%.

  When the dimming instruction value reaches the first dimming threshold value OT1 (dimming level 5%), the control circuit unit 4 reduces the dimming level of the second LED load 62 from 5% to Xb%, and the second LED load The second lighting circuit unit 32 is driven so that 62 lights up at the dimming level Xb%. At this time, the control circuit unit 4 increases the dimming level of the first LED load 61 from 0% to Xb%, and drives the first lighting circuit unit 31 so that the first LED load 61 lights up at the dimming level Xb%. To do.

  Then, as the dimming instruction value increases, the control circuit unit 4 drives the second lighting circuit unit 32 so as to gradually lower the dimming level of the second LED load 62. Further, as the dimming instruction value increases, the control circuit unit 4 drives the first lighting circuit unit 31 so as to gradually increase the dimming level of the first LED load 61.

  When the dimming instruction value reaches the second dimming threshold OT2 (dimming level 6%), the control circuit unit 4 reduces the dimming level of the second LED load 62 from Xa% to 0%, and the second LED load The second lighting circuit unit 32 is controlled so that the dimming level 62 becomes 0%. In addition, the control circuit unit 4 increases the dimming level of the first LED load 61 from Xc% to 6%, and drives the first lighting circuit unit 31 so that the first LED load 61 lights up at the dimming level of 6%. .

  In the heavy lighting section OR12, the control circuit unit 4 controls the first dimming level so that the sum of the dimming level of the first LED load 61 and the dimming level of the second LED load 62 becomes the dimming level corresponding to the dimming instruction value. The lighting circuit unit 31 and the second lighting circuit unit 32 are controlled.

  When the dimming instruction value is higher than the second dimming threshold OT2, the control circuit unit 4 controls the second lighting circuit unit 32 so that the dimming level of the second LED load 62 becomes 0%, and the first LED load 61 is controlled. Drives the first lighting circuit unit 31 so that the first load current I1 based on the dimming instruction value is supplied.

  When the lighting device 2 of the present embodiment is configured as described above, it is possible to avoid that both the first LED load 61 and the second LED load 62 are turned off simultaneously.

  The lighting device 2 may include three or more lighting circuit units.

  The control circuit unit 4 may be provided with a current detection circuit or the like to monitor the value of the current flowing through the first inductor L1 and the second inductor L2. In this case, the control circuit unit 4 causes the first lighting circuit unit 31 to switch the first switching element Q1 and the second switching element Q2 from the off state to the on state when the current value is equal to or less than a predetermined current value to be set. The second lighting circuit unit 32 may be controlled.

  The lighting device 2 according to the present embodiment applies a voltage obtained by stepping down a DC input voltage to an LED load (for example, the first LED load 61 and the second LED load 62) and applies a load current (for example, a first load current I1, a second load current). A plurality of lighting circuit portions (for example, a first lighting circuit portion 31 and a second lighting circuit portion 32) for supplying the load current I2) to the LED load are provided. The lighting device 2 further includes a control circuit unit 4 that controls the operation of the plurality of lighting circuit units based on the instructed dimming level (dimming instruction value) and increases or decreases the amplitude of the load current. The control circuit unit 4 sets a plurality of dimming ranges (for example, a first dimming range OR1 and a second dimming range OR2) between the dimming lower limit value OL and the dimming upper limit value OU. Each range is associated with at least one lighting circuit unit. The control circuit unit 4 controls the lighting circuit unit associated with the dimming range to which the instructed dimming level belongs, and supplies a load current to the LED load.

  Since the lighting device 2 of the present embodiment switches a plurality of lighting circuit units according to the dimming level and controls the plurality of lighting circuit units by DC dimming, a large-capacitance capacitor is provided between the output terminals. do not need. Therefore, the lighting device 2 of the present embodiment can be dimmed at a low dimming level, and can improve the responsiveness and ensure the synchronism between instruments.

  In the lighting device 2 of the present embodiment, it is preferable that the plurality of lighting circuit units include a first lighting circuit unit 31 and a second lighting circuit unit 32. The first lighting circuit unit 31 preferably supplies the first load current I1 to the first LED load 61. The second lighting circuit unit 32 preferably supplies the second load current I2 to the second LED load 62. The control circuit unit 4 includes a first dimming threshold value OT1 that is higher than the dimming lower limit value OL and lower than the dimming upper limit value OU, and a second dimming threshold value that is lower than the dimming upper limit value and equal to or higher than the first dimming threshold value OT1. It is preferable to set OT2. The control circuit unit 4 sets the dimming range equal to or smaller than the dimming upper limit value OU and equal to or greater than the first dimming threshold value OT1 as the first dimming range OR1, and equal to or greater than the dimming lower limit value OL and equal to the second dimming threshold value OT2. The following dimming range is preferably the second dimming range OR2. If the instructed dimming level is the first dimming range OR1, the control circuit unit 4 controls the first lighting circuit unit 31 to supply the first load current I1 corresponding to the dimming level to the first LED load 61. It is preferable to supply to. If the instructed dimming level is the second dimming range OR2, the control circuit unit 4 controls the second lighting circuit unit 32 to set the second load current I2 corresponding to the dimming level to the second LED load. It is preferable to supply to 62.

  When the lighting device 2 of the present embodiment is configured as described above, the first lighting circuit unit 31 corresponding to a high dimming level and the second lighting circuit unit 32 corresponding to a low dimming level are obtained by DC dimming. It is controlled. Since the lighting device 2 can perform low dimming by DC dimming, a large-capacity capacitor is not required between the output terminals in order to control dimming at a low dimming level. Therefore, the lighting device 2 of the present embodiment can improve the responsiveness and ensure the synchronism between the instruments.

  In the lighting device 2 of the present embodiment, the first lighting circuit unit 31 preferably includes a first switching element Q1 that is ON / OFF controlled by the control circuit unit 4 and connected in series to the first LED load 61. The first lighting circuit unit 31 is preferably formed of a step-down chopper circuit further including a first detection resistor R1 through which the first load current I1 flows when the first switching element Q1 is in the ON state. The control circuit unit 4 preferably turns off the first switching element Q1 when the voltage across the first detection resistor R1 reaches the first upper limit value after turning on the first switching element Q1. The second lighting circuit unit 32 preferably includes a second switching element Q <b> 2 that is on / off controlled by the control circuit unit 4 and connected in series to the second LED load 62. The second lighting circuit unit 32 is preferably formed of a step-down chopper circuit further including a second detection resistor R2 through which the second load current I2 flows when the second switching element Q2 is in the ON state. The control circuit unit 4 preferably turns off the second switching element Q2 when the voltage across the second detection resistor R2 reaches the second upper limit value after turning on the second switching element Q2. The resistance value of the second detection resistor R2 is preferably larger than the resistance value of the first detection resistor R1.

  When the lighting device 2 according to the present embodiment is configured as described above, the second lighting circuit unit 32 is configured so that the resistance value of the second detection resistor R2 is larger than the resistance value of the first detection resistor R1. 2 The detection voltage Vb can be detected in a wider range. Therefore, the lighting device 2 can adjust the second load current I2 with high accuracy even with a low dimming instruction value.

  In the lighting device 2 of the present embodiment, the first dimming threshold value OT1 is preferably larger than the second dimming threshold value OT2. The control circuit unit 4 preferably sets a range higher than the first dimming threshold OT1 and lower than the second dimming threshold OT2 as the heavy lighting section OR12. When the instructed dimming level belongs to the heavy lighting section OR12, the control circuit unit 4 preferably controls both the first lighting circuit unit 31 and the second lighting circuit unit 32. The control circuit unit 4 preferably supplies the first load current I1 to the first LED load 61 and supplies the second load current I2 to the second LED load 62.

  When the lighting device 2 of the present embodiment is configured as described above, when the control circuit unit 4 switches from the first lighting circuit unit 31 to the second lighting circuit unit 32, the first LED load 61 and the second LED load 62 are changed. It is possible to avoid both of them turning off at the same time. Similarly, when the control circuit unit 4 switches from the second lighting circuit unit 32 to the first lighting circuit unit 31, the lighting device 2 similarly turns off both the first LED load 61 and the second LED load 62 at the same time. Can be avoided.

  The lighting fixture 1 of this embodiment is demonstrated with reference to FIG. 4A, FIG. 4B, FIG. 5, and FIG. In the following description, the vertical direction is defined in FIG. 4A.

  The lighting fixture 1 of this embodiment is provided with the light source part 10 which has the 1st LED load 61 which consists of several light emitting diodes 611, and the 2nd LED load 62 which consists of several light emitting diodes 621 (refer FIG. 1).

  As shown in FIG. 4A, the lighting fixture 1 is formed in a separate type in which the lighting device 2 is arranged at a location different from the light source unit 10. That is, the fixture main body 11 that houses the light source unit 10 is embedded in the ceiling 100, and the lighting device 2 is provided on the back surface (upper surface) of the ceiling 100 at a location away from the fixture main body 11. .

  The instrument main body 11 is formed in a bottomed cylindrical shape having an open lower end portion, for example, by an aluminum die-cast metal. In the instrument main body 11, the light source unit 10 is disposed on the inner upper bottom. The light emitting diode 611 and the light emitting diode 621 are mounted on the circuit board 60 so that the light irradiation direction is downward in order to irradiate the external space with light from the lower end of the instrument body 11.

  As shown in FIG. 5, a light emitting diode 611 and a light emitting diode 621 are mounted on the same circuit board 60 in the light source unit 10. On the circuit board 60, a plurality of rows in which a plurality of light emitting diodes 611 are arranged linearly in one direction and a plurality of rows in which the plurality of light emitting diodes 621 are arranged in a straight line in one direction are perpendicular to the one direction. In the intersecting direction, they are alternately arranged for each column. Note that the light-emitting diode 611 and the light-emitting diode 621 are preferably arranged so as to fit in the circular region 601.

  The circuit board 60 is provided with a connector CN1 and a connector CN2. The connector CN1 is electrically connected to the first LED load 61 as shown in FIG. The connector CN2 is electrically connected to the second LED load 62.

  A lead wire 14 is electrically connected to the connector CN1 and the connector CN2. As shown in FIGS. 4A and 6, the lighting device 2 is electrically connected to the light source unit 10 housed in the instrument main body 11 by a lead wire 14 via a connector 13.

  As shown in FIG. 4A, a light-transmitting plate 12 for diffusing light from the light-emitting diode 611 and the light-emitting diode 621 is provided in the opening at the lower end of the instrument body 11.

  Moreover, the lighting fixture 1 may be comprised as an integrated lighting fixture built in the fixture main body 11 with the lighting device 2 and the light source part 10, as shown to FIG. 4B. The integrated lighting fixture 1 is formed of an aluminum plate or a copper plate on the surface opposite to the surface on which the light emitting diode 611 and the light emitting diode 621 of the circuit board 60 are mounted, and the heat radiating plate 15 arranged in contact with the fixture body 11. Is provided. The radiator plate 15 and the instrument body 11 can radiate the heat generated by the light emitting diode 611 and the light emitting diode 621 to the outside.

  Since the lighting fixture 1 of this embodiment is provided with the above-mentioned lighting device 2 having a plurality of lighting circuit units that are driven according to the dimming instruction value, it can be dimmed at a low dimming level and has a response. Thus, the synchronism between the instruments can be ensured.

  In addition, in the lighting fixture 1 of this embodiment, the 1st LED load 61 may be comprised by the one light emitting diode 611. FIG. Further, the second LED load 62 may be configured by one light emitting diode 621. The numbers of the light emitting diodes 611 and the light emitting diodes 621 and the arrangement positions on the circuit board 60 are not limited to the present embodiment. Moreover, the structure of the lighting fixture 1 is not limited to this embodiment.

  The luminaire 1 of this embodiment includes a lighting device 2 and a plurality of LED loads. Each of the plurality of LED loads includes one to a plurality of light emitting diodes, and is electrically connected to the lighting circuit unit on a one-to-one basis.

  Since the lighting fixture 1 of the present embodiment is configured as described above, it has a plurality of lighting circuit units that are driven according to the dimming instruction value by DC dimming, and thus dimming is possible at a low dimming level. In addition, the responsiveness can be improved and the synchronism between the instruments can be ensured.

  In the lighting fixture 1 of the present embodiment, the plurality of LED loads are preferably provided on the same circuit board 60.

  If the lighting fixture 1 of this embodiment is comprised as mentioned above, an irradiation surface can be uniformly irradiated according to a light control level irrespective of which LED load is used.

DESCRIPTION OF SYMBOLS 1 Lighting fixture 2 Lighting device 31 1st lighting circuit part 32 2nd lighting circuit part 4 Control circuit part 60 Circuit board 61 1st LED load 62 2nd LED load I1 1st load current I2 2nd load current Q1 1st switching element Q2 1st 2 switching elements R1 1st detection resistance R2 2nd detection resistance OL Dimming lower limit OR1 1st dimming range OR12 Double lighting section OR2 2nd dimming range OT1 1st dimming threshold OT2 2nd dimming threshold OU Dimming upper limit value

Claims (6)

A plurality of lighting circuit units for applying a voltage obtained by stepping down a DC input voltage to the LED load and supplying a load current to the LED load, and controlling operations of the plurality of lighting circuit units based on the instructed dimming level A control circuit unit for increasing or decreasing the amplitude of the load current,
The control circuit unit sets a plurality of dimming ranges between a dimming lower limit value and a dimming upper limit value, and associates each of the plurality of dimming ranges with at least one lighting circuit unit, and is instructed. The lighting device characterized by controlling the lighting circuit unit associated with the dimming range to which the dimming level belongs, and supplying the load current to the LED load. The plurality of lighting circuit units includes a first lighting circuit unit and a second lighting circuit unit,
The first lighting circuit unit supplies a first load current to the first LED load,
The second lighting circuit unit supplies a second load current to the second LED load,
The control circuit unit includes a first dimming threshold value that is higher than the dimming lower limit value and lower than the dimming upper limit value, and a second dimming threshold value that is lower than the dimming upper limit value and greater than or equal to the first dimming threshold value. And set
The dimming range that is equal to or lower than the dimming upper limit value and equal to or higher than the first dimming threshold is defined as a first dimming range,
The dimming range that is not less than the dimming lower limit value and not more than the second dimming threshold is defined as a second dimming range,
If the instructed dimming level is within the first dimming range, the control circuit unit controls the first lighting circuit unit to set the first load current according to the dimming level to the first LED. If the dimming level supplied to the load and the instructed dimming level is within the second dimming range, the second lighting circuit unit is controlled so that the second load current corresponding to the dimming level is supplied to the second LED. The lighting device according to claim 1, wherein the lighting device is supplied to a load. The first lighting circuit unit includes a first switching element that is ON / OFF controlled by the control circuit unit and connected in series to the first LED load, and a first load current that flows when the first switching element is in an ON state. Formed of a step-down chopper circuit having one detection resistor,
The control circuit unit turns off the first switching element when the voltage across the first detection resistor reaches a first upper limit value after turning on the first switching element,
The second lighting circuit unit is controlled to be turned on / off by the control circuit unit and connected in series to the second LED load, and the second load current flows when the second switching device is on. A step-down chopper circuit having a second detection resistor;
The control circuit unit turns off the second switching element when the voltage across the second detection resistor reaches a second upper limit value after turning on the second switching element,
The lighting device according to claim 2, wherein a resistance value of the second detection resistor is larger than a resistance value of the first detection resistor. The first dimming threshold value is larger than the second dimming threshold value,
The control circuit unit sets a range higher than the first dimming threshold and lower than the second dimming threshold as a heavy lighting section, and when the instructed dimming level belongs to the heavy lighting section, Controlling both the first lighting circuit unit and the second lighting circuit unit to supply the first load current to the first LED load and supply the second load current to the second LED load. The lighting device according to claim 2, wherein the lighting device is a light-emitting device. The lighting device according to any one of claims 1 to 4, and a plurality of LED loads,
Each of the LED loads includes one to a plurality of light emitting diodes, and is electrically connected to the lighting circuit unit on a one-to-one basis. The lighting fixture according to claim 5, wherein the plurality of LED loads are provided on the same circuit board.

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