JP7133787B2 - Lighting systems, lighting control systems and luminaires - Google Patents

Description

The present invention relates generally to lighting systems, lighting control systems, and lighting fixtures.

Conventionally, there is a lighting device capable of dimming a light emitting element.

For example, in Patent Document 1, a light control console outputs a DMX signal to a lighting device by executing a predetermined production program. The lighting device converts the input DMX signal into a PWM signal having a duty ratio corresponding to the gradation indicated by the DMX signal. At this time, the lighting device generates the PWM signal according to the correspondence indicated by the dimming curve indicating the correspondence between the dimming ratio and the duty ratio. Then, the lighting device performs dimming control of the light emitting element so as to emit light with brightness according to the dimming ratio corresponding to the duty ratio indicated by the PWM signal. The dimming curve has linearity and becomes a straight line in the dimming ratio range of 100% to 2.2%. Furthermore, the dimming curve has nonlinearity in the dimming ratio range from 2.2% to 0%, and becomes a curve.

Further, the LED lighting device of Patent Document 2 receives a phase-controlled voltage of an AC power source, rectifies the phase-controlled voltage, and supplies a load current to an LED light source using the rectified output as a power source. Further, the LED lighting device dims the LED light source based on the phase or voltage of the phase-controlled AC power supply voltage. The LED lighting device dims the brightness of the LED light source as the conduction angle of the phase-controlled voltage is smaller.

JP 2015-144080 A Japanese Patent Application Laid-Open No. 2018-56100

The above-mentioned Patent Document 2 can gradually dim and fade out the LED light source by decreasing the conduction angle of the voltage of the phase-controlled AC power supply. However, there is a problem that the smaller the conduction angle, the lower the effective value of the voltage, and the operation of the LED lighting device (lighting system) stops before the light source is extinguished.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a lighting system, a lighting control system, and a lighting system capable of maintaining the operation of a control circuit at least until the light source is turned off when the light output is faded out by phase control of the AC voltage. to provide the equipment.

A lighting system according to an aspect of the present invention includes a DC power supply circuit, a converter, a phase reading circuit, a control circuit, and a control power supply. The DC power supply circuit receives a phase control voltage, which is an AC voltage with a variable conduction angle, and outputs the DC voltage. The converter receives the DC voltage and supplies lighting power to the light source. The phase reading circuit detects the conduction angle. The control circuit controls at least the converter according to the detected value of the conduction angle, and performs dimming control such that the smaller the detected value of the conduction angle, the lower the dimming ratio of the light source. A control power supply generates a control voltage for operating the control circuit. The control power supply maintains the control voltage at a value at which the control circuit can operate at least until the light source is extinguished while fade-out control for fading out the light output of the light source is performed as the dimming control. The DC power supply circuit has a capacitor and causes the capacitor to generate the DC voltage. When the fade-out control is performed, the control power supply generates the control voltage from the DC voltage for a predetermined period including the timing of turning off the light source.

A lighting control system according to one aspect of the present invention comprises a series circuit of the lighting system described above and a dimmer connected to an AC power supply. The dimmer outputs a phase control voltage, which is an AC voltage with a variable conduction angle, to the lighting system.

A lighting fixture according to an aspect of the present invention includes the lighting system described above, a light source supplied with the lighting power from the lighting system, and a housing supporting at least the light source.

As described above, according to the present invention, when the light output is faded out by phase control of the AC voltage, the operation of the control circuit can be maintained at least until the light source is turned off.

FIG. 1 is a block diagram showing a lighting control system including a lighting system according to an embodiment. FIG. 2 is a waveform diagram showing input waveforms of the same lighting system. FIG. 3 is a schematic circuit diagram showing a PFC circuit of the same lighting system. FIG. 4 is a schematic circuit diagram showing a first control power supply of the same lighting system. FIG. 5 is a waveform diagram for explaining fade-out control of the same lighting system. FIG. 6 is a waveform diagram for explaining fade-out control of a comparative example. FIG. 7 is another waveform diagram for explaining fade-out control of the lighting system according to the embodiment. FIG. 8 is a perspective view showing a lighting fixture provided with the same lighting system.

The following embodiments generally relate to lighting systems, lighting control systems, and lighting fixtures. More particularly, the present invention relates to a lighting system, a lighting control system, and a lighting fixture that dim a light source by phase control that changes the conduction angle of an AC voltage. In addition, the embodiment described below is merely an example of the embodiment of the present invention. The present invention is not limited to the following embodiments, and various modifications can be made according to design and the like as long as the effects of the present invention can be achieved.

The lighting system, lighting control system, and lighting fixtures of the embodiments are mainly used in event venues, stores, offices, and the like. In particular, the lighting system, lighting control system, and lighting fixture of the embodiments are preferably used in a wedding reception hall. Also, the lighting system, lighting control system, and lighting fixture of the embodiments may be used in dwelling units, collective housing, and the like.

Embodiments will be described below based on the drawings.

A lighting control system A1 of the embodiment includes a lighting device 1 and a dimmer 2, as shown in FIG. A series circuit of the illumination device 1 and the dimmer 2 is connected across the AC power supply 9 . The AC power supply 9 is a commercial power supply with a nominal voltage of 100 V (or 200 V) and a frequency of 50 Hz or 60 Hz.

The dimmer 2 phase-controls the AC voltage Va supplied from the AC power supply 9 to the lighting device 1 . That is, the illumination device 1 receives the AC voltage Va whose phase is controlled by the dimmer 2 as the phase control voltage Vb. The dimmer 2 adjusts the conduction angle, which is the energization period for each half wave of the phase control voltage Vb, and the lighting device 1 performs dimming according to the conduction angle. In this case, the conduction angle corresponds to instruction information representing an instruction value of a dimming ratio (dimming level) of the light source 12, which will be described later. The dimmer 2 is a dimmer operation console equipped with, for example, a rotary or slide-type operation unit operated by a user, or a dimmer that outputs a phase control voltage Vb converted from a DMX signal output from the dimmer operation console. It is an optical unit, and the conduction angle is adjusted by the user operating the operation part.

The lighting device 1 is a lighting fixture capable of dimming, and includes a lighting system 11 and a light source 12 as shown in FIG. 1 . The lighting system 11 of this embodiment is configured by a lighting device. The lighting system 11 and the light source 12 may be housed in a common housing and configured integrally, or the lighting system 11 and the light source 12 may be configured separately.

The lighting system 11 includes a DC power supply circuit 1a, a converter 1b, a phase reading circuit 1c, a control circuit 1d, a rectifier circuit 1e, a constant voltage circuit 1f, a constant voltage circuit 1g, and a control power supply 1h. The DC power supply circuit 1 a has a rectifier circuit 111 , a PFC (Power Factor Correction) circuit 112 and a capacitor 113 . The controlled power supply 1 h includes a first controlled power supply 101 and a second controlled power supply 102 .

A rectifier circuit 111 is a full-wave rectifier circuit having a diode bridge or the like, and receives the phase control voltage Vb. A rectifier circuit 111 full-wave rectifies the phase control voltage Vb and outputs a pulsating current voltage Vc. FIG. 2 shows the waveform of the pulsating voltage Vc. The pulsating current voltage Vc in FIG. 2 is phase-controlled in the same manner as the phase-controlled voltage Vb, and the conduction angle θ is defined as the period during which the current is applied every half wave. In FIG. 2, the dashed-dotted line indicates the waveform of the full-wave rectified voltage Ve obtained by full-wave rectifying the AC voltage Va. Furthermore, a filter circuit may be provided in the preceding stage of the rectifier circuit 111 . The filter circuit has, for example, an inductor and a capacitor for noise removal, and a surge absorber, and attenuates unnecessary frequency components (for example, high frequency noise).

The PFC circuit 112 is a switching power supply circuit (power factor correction circuit) having a power factor correction function. The PFC circuit 112 receives the pulsating current voltage Vc, converts the pulsating current voltage Vc into a DC voltage, and outputs the DC voltage. A capacitor 113 is connected between the output terminals of the PFC circuit 112 . The capacitor 113 smoothes the DC voltage output from the PFC circuit 112 and a DC voltage Vd is generated across the capacitor 113 . The PFC circuit 112 is a step-up chopper circuit or step-up/step-down chopper circuit having a semiconductor switching element, and the pulsating current voltage Vc is converted into a DC voltage Vd by turning on and off the semiconductor switching element. For example, the PFC circuit 112 is configured with a flyback converter (PFC flyback converter) having a power factor correction function. Alternatively, the PFC circuit 112 may be a conventional flyback converter or other switching power supply circuit such as a SEPIC circuit.

FIG. 3 shows a circuit example of the PFC circuit 112 . In FIG. 3, the PFC circuit 112 is a PFC flyback converter comprising a transformer 112a, a switching element 112b, a diode 112c, a drive circuit 112d, and diodes 112e, 112f. A pulsating voltage Vc is applied to the series circuit of the primary winding N1 of the transformer 112a and the switching element 112b. The switching element 112b is, for example, an enhancement type N-channel MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). With respect to the pulsating current voltage Vc, the primary winding N1 is arranged on the high side and the switching element 112b is arranged on the low side. A regeneration diode 112c is connected across the primary winding N1. The driving circuit 112d switches the gate voltage of the switching element 112b between H level and L level, thereby switching the switching element 112b on and off. The anode of the diode 112e is connected to one end of the secondary winding N2 of the transformer 112a. The cathode of diode 112 e is connected to the positive terminal of capacitor 113 . The other end of the secondary winding N2 of the transformer 112a is connected to the negative electrode of the capacitor 113.

Then, the drive circuit 112d turns on and off the switching element 112b, so that the current flowing through the primary winding N1 of the transformer 112a is turned on and off. As a result, an induced voltage is generated in the secondary winding N2 of the transformer 112a, the capacitor 113 is charged via the diode 112e, and a DC voltage Vd is generated across the capacitor 113. The drive circuit 112d turns the switching element 112b on and off based on an instruction from the control circuit 1d to match the DC voltage Vd with the voltage target value. Switching control of the switching element 112b by the drive circuit 112d may be any of discontinuous mode, continuous mode, and critical mode. Preferably, the drive circuit 112d detects the zero crossing of the switching current flowing through the switching element 112b and the peak value of the inductor current to control the switching of the switching element 112b.

As described above, the DC power supply circuit 1a receives the phase-controlled voltage Vb phase-controlled by the dimmer 2 and outputs the DC voltage Vd. The voltage value of DC voltage Vd is preferably a value sufficiently larger than the sum of the output voltage of converter 1b and first control voltage V11, which will be described later.

The converter 1b is a DC/DC converter, receives a DC voltage Vd, and supplies the light source 12 with a DC load current (output current) Io. The converter 1b makes the value of the load current Io match the current target value by controlling the output based on the instruction from the control circuit 1d. Converter 1b changes the current target value according to an instruction from control circuit 1d. That is, the converter 1b dims the light source 12 so as to achieve the dimming ratio instructed by the control circuit 1d. The converter 1b preferably has, for example, a buck converter, a boost converter, a buck-boost converter, or a constant current regulator.

The light source 12 includes a plurality of LEDs (Light Emitting Diodes) as a plurality of solid state light emitting devices. The light source 12 emits illumination light (light output) by being supplied with the load current Io from the converter 1b. The plurality of LEDs included in the light source 12 are connected in series, or connected in series and in parallel.

The phase reading circuit 1c corresponds to an information acquiring section that receives instruction information representing the instruction value of the dimming ratio of the light source 12 from the outside. In this embodiment, the conduction angle θ of the phase control voltage Vb corresponds to the indication information. The phase reading circuit 1c detects the conduction angle θ and outputs a conduction angle detection signal Sa.

The phase reading circuit 1c full-wave rectifies the phase control voltage Vb, compares the rectified voltage of the phase control voltage Vb with a judgment reference value, and generates a PWM (Power Width Modulation) signal (rectangular wave signal) based on the comparison result. ). The PWM signal is a pulse signal synchronized with the phase control voltage Vb, and the on-duty of the PWM signal corresponds to the conduction angle θ. Specifically, when the conduction angle θ increases, the on-duty of the PWM signal increases, and when the conduction angle θ decreases, the on-duty of the PWM signal decreases.

The phase reading circuit 1c smoothes the PWM signal to generate a conduction angle detection signal Sa, and outputs the conduction angle detection signal Sa to the control circuit 1d. The on-duty of the PWM signal corresponds to the indicated value of the dimming ratio. In other words, the voltage value of the conduction angle detection signal Sa corresponds to the detected value of the conduction angle θ. Therefore, the indicated value of the dimming ratio is reflected in the voltage value of the conduction angle detection signal Sa obtained by smoothing the PWM signal. That is, the higher the indicated value of the dimming ratio, the higher the voltage value of the conduction angle detection signal Sa, and the lower the indicated value of the dimming ratio, the smaller the voltage value of the conduction angle detection signal Sa.

The phase control voltage Vb may fluctuate instantaneously due to the effects of noise, ripple, surge voltage, and the like. Therefore, in the phase reading circuit 1c, it is preferable that the time constant of the smoothing circuit for smoothing the PWM signal is set to a value capable of absorbing instantaneous fluctuations in the phase control voltage Vb. As a result, problems such as flickering and erroneous light emission of the light source 12 due to instantaneous fluctuations in the phase control voltage Vb can be suppressed.

The control circuit 1d has a computer. A part or all of the functions of the control circuit 1d are implemented by the computer executing the program. A computer has a processor that operates according to a program as a main hardware configuration. Any type of processor can be used as long as it can implement functions by executing a program. The processor is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or LSI (large scale integration). Here, they are called ICs and LSIs, but they may be called system LSIs, VLSIs (very large scale integration), or ULSIs (ultra large scale integration) depending on the degree of integration. A field programmable gate array (FPGA), which is programmed after the LSI is manufactured, or a reconfigurable logic device capable of reconfiguring the junction relationships inside the LSI or setting up circuit partitions inside the LSI for the same purpose. can be done. A plurality of electronic circuits may be integrated on one chip or may be provided on a plurality of chips. A plurality of chips may be integrated into one device, or may be provided in a plurality of devices. The program is recorded in a non-temporary recording medium such as a computer-readable ROM, optical disk, hard disk drive, or the like. The program may be pre-stored in a recording medium, or may be supplied to the recording medium via a wide area network including the Internet.

Also, the control circuit 1d may include a control IC. The control IC realizes part or all of the functions of the control circuit 1d by an electric circuit formed in the IC chip without executing a program.

The control circuit 1 d acquires the detected value of the DC voltage Vd from the PFC circuit 112 . The control circuit 1d outputs a voltage control signal to the PFC circuit 112 so that the DC voltage Vd matches the voltage target value. In the PFC circuit 112, the drive circuit 112d turns on and off the switching element 112b based on the voltage control signal from the control circuit 1d to match the value of the DC voltage Vd with the voltage target value.

Further, the control circuit 1d acquires the detected value of the load current Io from the converter 1b. Then, the control circuit 1d generates a current control signal based on the conduction angle detection signal Sa and the detected value of the load current Io, and outputs the current control signal to the converter 1b.

The control circuit 1d reads the conduction angle θ (indication value of the dimming ratio) from the voltage value of the conduction angle detection signal Sa, and determines the current target value according to the read conduction angle θ. Then, control circuit 1d controls the operation of converter 1b so that the deviation (difference) between the detected value of load current Io and the current target value becomes small (approaches zero).

The control circuit 1d performs at least one of amplitude dimming, burst dimming, and the like to dim the light source 12 by controlling the load current Io. Amplitude dimming controls the dimming ratio of light source 12 by continuously supplying load current Io to light source 12 and controlling the magnitude of load current Io. In this case, the control parameter of converter 1b is the magnitude of load current Io. Burst dimming controls the dimming ratio of the light source 12 by intermittently supplying the load current Io to the light source 12 and PWM-controlling the ON period during which the load current Io is supplied to the light source 12 . In this case, the control parameter of the converter 1b is the ON period during which the load current Io is supplied to the light source 12. FIG. When the control circuit 1d performs switching control of the switching elements of the converter 1b, it is generally preferable to perform switching at a high frequency of several tens of kHz to several hundreds of kHz. Further, when performing burst dimming, the control circuit 1d preferably intermittently outputs the load current Io at a low frequency lower than several tens of kHz to several hundreds of kHz. Further, the control circuit 1d may use a method other than amplitude dimming and burst dimming as a dimming method for the light source 12, and the dimming method for the light source 12 is not limited to a specific dimming method.

That is, the control circuit 1d adjusts the control parameter so that the deviation between the detected value of the load current Io and the current target value is small, and performs feedback control for controlling the converter 1b. As a result, the load current Io is controlled so that the dimming ratio of the light source 12 becomes the indicated value. The larger the conduction angle θ, the higher the indicated value of the dimming ratio. Therefore, the larger the conduction angle θ, the larger the current target value. Also, the smaller the conduction angle θ, the lower the indicated value of the dimming ratio. Therefore, the smaller the conduction angle θ, the smaller the current target value. The dimming ratio takes a value within the range of 0-100%. If the dimming ratio is 0%, the light source 12 is turned off. If the dimming ratio is 100%, the light source 12 is fully lit. In this embodiment, the control circuit 1d can control the dimming ratio within the range of 1% to 100% when the light source 12 is turned on. In this case, when the light source 12 is turned on, the lower limit of the dimming ratio (lower limit of dimming) that can be adjusted by the lighting system 11 is 1%. Note that the dimming lower limit value is not limited to a specific value.

Next, the control voltage of the lighting system 11 will be explained. The control power supply 1h receives voltages V1, V2, and V3 and outputs a first control voltage V11 (control voltage) and a second control voltage V12 (control voltage).

Specifically, the rectifier circuit 1e full-wave rectifies the phase control voltage Vb and outputs a full-wave rectified voltage of the phase control voltage Vb. The constant voltage circuit 1 f receives the output of the rectifier circuit 1 e (the full-wave rectified voltage of the phase control voltage Vb) and outputs a DC voltage V 1 to the first control power supply 101 . The constant voltage circuit 1f is composed of a linear regulator such as a series regulator or a shunt regulator, and controls the voltage V1 to a constant voltage value. Linear regulators include resistors, transistors, capacitors, Zener diodes, and the like.

The PFC circuit 112 outputs a pulse-like voltage V2 while performing power conversion processing for converting the pulsating current voltage Vc into the DC voltage Vd. The PFC circuit 112 of the present embodiment turns on and off the switching element 112b during a steady period after startup to turn on or off the current flowing through the primary winding N1 of the transformer 112a (see FIG. 3). Then, the induced voltage generated in the control winding N3 (see FIG. 3) of the transformer 112a is output to the first control power supply 101 as the voltage V2 through the diode 112f.

The constant voltage circuit 1 g receives a DC voltage Vd, which is the voltage across the capacitor 113 , and outputs a DC voltage V 3 to the first control power supply 101 . The constant voltage circuit 1g is composed of a linear regulator such as a series regulator or a shunt regulator, and controls the voltage V3 to a constant voltage value. Linear regulators include resistors, transistors, capacitors, Zener diodes, and the like.

The first control power supply 101 receives the three voltages V1, V2, and V3 described above, and generates a DC first control voltage V11 using one of the three voltages V1, V2, and V3. In this embodiment, the magnitude relationships among the three voltages V1, V2, and V3 are V2>V1 and V2>V3. The first control power supply 101 performs constant voltage control of the first control voltage V11 to a constant voltage value. The first control voltage V11 serves as an operating power supply for the PFC circuit 112 and the converter 1b. For example, the first control voltage V11 becomes a drive voltage for each switching element (FET, bipolar transistor, etc.) of the PFC circuit 112 and the converter 1b. The first control voltage V11 is desirably a minimum voltage value capable of driving the switching elements of the PFC circuit 112 and the converter 1b, taking heat generation of components into consideration.

FIG. 4 shows a circuit example of the first control power supply 101. As shown in FIG. 4, the first controlled power supply 101 has diodes 121, 122, capacitor 123, resistor 124, Zener diode 125, transistor 126 and capacitor 127. In FIG.

The anode of the diode 121 is connected to the output of the constant voltage circuit 1f, and the cathode of the diode 121 is connected to the positive terminal of the capacitor 123. The anode of diode 122 is connected to the output of constant voltage circuit 1 g and the cathode of diode 122 is connected to the positive terminal of capacitor 123 . That is, capacitor 123 receives voltage V1 through diode 121 and voltage V3 through diode 122 . Further, capacitor 123 is applied with voltage V2. In this embodiment, a DC voltage of about 15 to 25 V is generated across the capacitor 123 .

A series circuit of resistor 124 and Zener diode 125 is connected in parallel with capacitor 123 . One end of resistor 124 is connected to the positive electrode of capacitor 123 and the other end of resistor 124 is connected to the cathode of Zener diode 125 . The anode of Zener diode 125 is connected to the negative terminal of capacitor 123 . The transistor 126 is an npn-type bipolar transistor, and the cathode of the Zener diode 125 is connected to the base of the transistor 126 . The collector of transistor 126 is connected to the positive terminal of capacitor 123 and the emitter of transistor 126 is connected to the positive terminal of capacitor 127 . The negative terminal of capacitor 127 is connected to the negative terminal of capacitor 123 .

In the first controlled power supply 101 described above, a voltage approximately equal to the Zener voltage of the Zener diode 125 is generated across the capacitor 127 . The first control power supply 101 outputs the voltage across the capacitor 127 as the first control voltage V11. In this embodiment, a DC voltage of about 12 V is generated as the first control voltage V11 (the voltage across the capacitor 127).

The second control power supply 102 receives the first control voltage V11 and outputs the second control voltage V12. The second control voltage V12 serves as an operating power supply for the control circuit 1d. The second control power supply 102 is composed of, for example, a linear regulator such as a series regulator or a shunt regulator, and performs constant voltage control of the second control voltage V12 to a constant voltage value. The second control voltage V12 may be any voltage value that enables the control circuit 1d to operate. In particular, it is desirable that the second control voltage V12 is a minimum voltage value that allows the control circuit 1d to operate, taking into account heat generation of components. In this embodiment, the second control voltage V12 is a DC voltage of about 5V.

In the starting period immediately after power supply from the AC power supply 9 to the lighting system 11 via the dimmer 2 is started, the PFC circuit 112 is not operating, and the voltage V1 out of the voltages V1, V2, and V3 is generated. The first control power supply 101 generates a first control voltage V11 from the voltage V1, and the second control power supply 102 generates a second control voltage V12. When the first control voltage V11 is generated, the PFC circuit 112 and the converter 1b can start their operations. When the second control voltage V12 is generated, the control circuit 1d starts operating. The control circuit 1d controls the PFC circuit 112, and the PFC circuit 112 starts outputting the DC voltage Vd. When the DC voltage Vd is output and reaches the voltage target value, the control circuit 1d controls the converter 1b, and the converter 1b starts outputting the load current Io.

Further, when the PFC circuit 112 starts operating, the switching element 112b is turned on and off to generate an induced voltage in the control winding N3 of the transformer 112a (see FIG. 3) to generate the voltage V2. The control winding N3 is designed to generate an induced voltage capable of generating the first control voltage V11 and the second control voltage V12. Then, when the second control voltage V12 is output and the starting period shifts to the steady period, the constant voltage circuit 1f stops outputting the voltage V1, and the first control power supply 101 changes the first control voltage V11 from the voltage V2. Generate. That is, the first control power supply 101 generates the first control voltage V11 from the voltage V1 during the startup period, and generates the first control voltage V11 from the voltage V2 during the steady period.

Note that the first control power supply 101 may generate the first control voltage V11 from the voltage V1 in both the starting period and the steady period. Also, the first control power supply 101 may generate the first control voltage V11 using both the voltages V1 and V2 in the steady period.

In the steady period, the control circuit 1d makes the value of the DC voltage Vd match the voltage target value. Further, in the steady period, the control circuit 1d controls the load current Io so that the dimming ratio of the light source 12 becomes the indicated value of the dimming ratio of the dimmer 2. FIG.

Next, the operation of the lighting system 11 instructed to fade out (dimming off operation) by the dimmer 2 will be described.

By the user operating the operation unit of the dimmer 2, a fade-out instruction is given to turn off the light source 12 by gradually decreasing the dimming ratio. Hereinafter, the operation of the dimmer 2 for instructing fade-out will be referred to as fade-out operation. When a fade-out operation is performed on the dimmer 2, the conduction angle θ gradually decreases, and the voltage value of the conduction angle detection signal Sa gradually decreases. Then, the control circuit 1d performs fade-out control to control the converter 1b so that the load current Io gradually decreases to 0 (zero). As a result, the dimming ratio of the light source 12 gradually decreases, the light source 12 is turned off, and the light output of the light source 12 fades out.

When a fade-out operation is performed on the dimmer 2, the conduction angle θ gradually decreases and the effective value of the pulsating current voltage Vc gradually decreases. When the load current Io drops below Io (1%) (when the dimming ratio of the light source 12 drops below the dimming lower limit value), the effective value of the pulsating current voltage Vc becomes excessively low. The PFC circuit 112 stops operating and the output voltage of the PFC circuit 112 becomes zero.

That is, when a fade-out operation is performed on the dimmer 2 and the load current Io drops below Io (1%), the effective value of the phase control voltage Vb reaches a value at which the PFC circuit 112 becomes inoperable. descend. As a result, in a comparative example (a lighting system that generates control voltages using only the voltages V1 and V2 without using the voltage V3), the light output of the light source 12 that fades out is less than the dimming lower limit. When the value suddenly drops to 0 (zero), the human eye may feel that the light source 12 has suddenly turned off. Such a rapid change in optical output makes people feel uncomfortable. However, in the field of stage lighting, event lighting, etc., it is necessary to cause the light output to decrease smoothly until the light source is turned off during the fade-out operation. For example, in a 40 W class lighting system, even if the dimming ratio becomes 1% or less during fade-out operation, it is required to gradually decrease the light output until the light source is extinguished. However, in a lighting system using a phase control voltage as an input, when the dimming ratio becomes 1% or less during fade-out operation, it is difficult to gradually decrease the light output until the light source is extinguished.

On the other hand, fade-out control according to this embodiment will be described with reference to FIG. FIG. 5 shows waveforms of the conduction angle detection signal Sa and the load current Io. In this case, the conduction angle detection signal Sa corresponds to the indicated value of the dimming ratio, and the load current Io corresponds to the light output of the light source 12 . When the fade-out operation is started at time t0, the voltage value of the conduction angle detection signal Sa decreases and the load current Io decreases. When the control circuit 1d fades out the optical output of the light source 12, the period during which the value of the load current Io is equal to or greater than Io (1%) is defined as a follow-up fade period Ta (second period). Furthermore, when fading out the optical output of the light source 12, the control circuit 1d sets the period from when the value of the load current Io becomes less than Io (1%) to when the light source 12 is turned off is a fixed fade period Tb (the second 1 period). Io (1%) is the value of the load current Io corresponding to the dimming lower limit value.

During the follow-up fade period Ta, the PFC circuit 112 is operating, and the DC voltage Vd maintains the voltage target value. In the follow-up fade period Ta, the control circuit 1d performs fade-out control while updating the control parameters as needed based on the voltage value of the conduction angle detection signal Sa. At this time, the control circuit 1d smoothly decreases the load current Io over the follow-up fade period Ta so that the light output is smoothly decreased to the human eye. The control circuit 1d reduces the load current Io over the follow-up fade period Ta using, for example, a 2.3rd power curve, a 2.7th power curve, or a 3.7th power curve used in the performance field. .

When the voltage value of the conduction angle detection signal Sa further decreases, the PFC circuit 112 stops operating during the fixed fade period Tb. However, immediately after the PFC circuit 112 stops operating, electric charge is accumulated in the capacitor 113, and the DC voltage Vd immediately after the PFC circuit 112 stops operating maintains the voltage target value. Therefore, the control circuit 1d uses the charging power of the capacitor 113 during the fixed fade period Tb to smoothly decrease the light output of the light source 12 until the light source 12 is turned off, thereby completing the fade-out control. That is, control circuit 1d controls converter 1b using DC voltage Vd (charge power of capacitor 113) during fixed fade period Tb. The converter 1b supplies lighting power to the light source 12 using the DC voltage Vd (charging power of the capacitor 113) during the fixed fade period Tb.

Specifically, during the fixed fade period Tb, the control circuit 1d fixes the control parameters of the converter 1b, electrically connects the positive terminal of the capacitor 113 to the positive terminal of the light source 12, and connects the negative terminal of the capacitor 113 to the negative terminal of the light source 12. electrically connected to the That is, the DC voltage Vd, which is the voltage across the capacitor 113 , is continuously applied to the light source 12 , and the charging power of the capacitor 113 is discharged to the light source 12 . As a result, during the fixed fade period Tb, the load current Io smoothly decreases to 0 (zero) so that the light output appears to the human eye to decrease smoothly. Therefore, the lighting system 11 can cause the human eye to feel that the light output has decreased smoothly without discomfort until the light source 12 is turned off during the fade-out operation.

Further, control circuit 1d may control converter 1b while updating the control parameters of converter 1b during fixed fade period Tb. That is, the control circuit 1d discharges the power charged in the capacitor 113 while controlling the load current Io during the fixed fade period Tb. During this fixed fade period Tb, the control circuit 1d changes the control parameters according to a predetermined control pattern so as to obtain a predetermined dimming curve. Further, the control circuit 1d may perform feedback control of the control parameter during the fixed fade period Tb. As a result, during the fixed fade period Tb, the load current Io smoothly decreases to 0 (zero) so that the light output appears to the human eye to decrease smoothly. Therefore, the lighting system 11 can cause the human eye to feel that the light output has decreased smoothly without discomfort until the light source 12 is turned off during the fade-out operation.

In the above description, the user is slowly operating the operating portion of the dimmer 2, and the conduction angle θ of the phase control voltage Vb is slowly decreasing. However, when the user quickly operates the operation unit of the dimmer 2 and the conduction angle θ of the phase control voltage Vb drops sharply, the amount of decrease in the load current Io (light output) follows the amount of reduction in the conduction angle θ. Sometimes I don't. Therefore, the control circuit 1d makes the update amount of the control parameter when the conduction angle .theta. decreases rapidly larger than the update amount of the control parameter when the conduction angle .theta. decreases slowly. That is, when the control circuit 1d performs fade-out control, the update amount of the control parameter when the decrease in the light output does not follow the decrease in the conduction angle θ is set so that the decrease in light output follows the decrease in the conduction angle θ. Make it larger than the update amount of the control parameter when The update amount of the control parameter is the difference between two control parameters successively set by the control circuit 1d.

In the PFC circuit 112 of FIG. 3, when the user quickly operates the operation section of the dimmer 2, the effective value of the phase control voltage Vb drops rapidly. As a result, the control circuit 1d sharply increases the on-duty of the switching element 112b to match the DC voltage Vd with the voltage target value. Therefore, the control circuit 1d can determine that if the on-duty of the switching element 112b suddenly increases, the conduction angle θ will suddenly decrease and the decrease in the light output cannot follow the decrease in the conduction angle θ. Therefore, the control circuit 1d increases the update amount of the control parameter when the reduction amount per unit time of the on-duty of the switching element 112b exceeds the threshold value. When the control parameter update amount increases, the converter 1b can rapidly decrease the load current Io, and the decrease in the light output follows the decrease in the conduction angle θ.

For example, when performing burst dimming, the control circuit 1d controls, as a control parameter, the length of the ON period during which the load current Io is intermittently supplied to the light source 12 . In this case, the control circuit 1d updates the on-period update amount (decrease amount of the on-period per unit time) when the decrease in the light output does not follow the decrease in the conduction angle θ in the follow-up fade period Ta. It should be larger than the update amount of the ON period when the decrease in output follows the decrease in conduction angle θ.

Further, when performing amplitude dimming, the control circuit 1d controls the magnitude of the load current Io as a control parameter. In this case, the control circuit 1d updates the load current Io (decrease amount of the load current Io per unit time) when the decrease in the light output does not follow the decrease in the conduction angle θ in the follow-up fade period Ta. , the update amount of the load current Io when the decrease in the light output follows the decrease in the conduction angle θ.

Furthermore, the control circuit 1d may switch between burst dimming and amplitude dimming. For example, the control circuit 1d performs amplitude dimming if the dimming ratio of the light source 12 is equal to or greater than a predetermined value. Further, the control circuit 1d performs burst dimming if the dimming ratio of the light source 12 is less than a predetermined value. Therefore, in the follow-up fade period Ta, the control circuit 1d updates the load current Io when the decrease in the light output does not follow the decrease in the conduction angle .theta. The amount of decrease in Io per unit time) is made larger than the update amount of the load current Io when the decrease in the light output follows the decrease in the conduction angle θ.

Therefore, even if the user quickly operates the operating portion of the dimmer 2 and the conduction angle .theta. decreases abruptly, the light output decreases following the decrease in the conduction angle .theta. As a result, fade-out control that can follow even a fast fade-out operation of the dimmer 2 is realized.

Next, the process of generating the first control voltage V11 and the second control voltage V12 in fade-out control will be described.

During the follow-up fade period Ta of fade-out control, the DC voltage Vd maintains the voltage target value, and the voltages V1 and V2 maintain the values during the steady period. Therefore, the control power supply 1h can generate the first control voltage V11 and the second control voltage V12 from the voltage V1 or the voltage V2 during the follow-up fade period Ta. For example, the control power supply 1h generates the first control voltage V11 and the second control voltage V12 from the voltage V2 in the first half of the follow-up fade period Ta, and generates the first control voltage V11 from the voltage V1 in the second half of the follow-up fade period Ta. , and a second control voltage V12.

However, when the dimming ratio of the light source 12 drops below the dimming lower limit value (the load current Io drops below Io (1%)) and the tracking fade period Ta shifts to the fixed fade period Tb, the phase control Voltages V1 and V2 also decrease due to the decrease in the effective value of voltage Vb. Therefore, the first control power supply 101 cannot generate the first control voltage V11 and the second control voltage V12 from the voltages V1 and V2.

That is, when a fade-out operation is performed on the dimmer 2 and the dimming ratio of the light source 12 drops below the dimming lower limit value, the voltage V1 during the fixed fade period Tb is reduced so that the first control power supply 101 becomes inoperable. value. When the dimming ratio of the light source 12 falls below the dimming lower limit value, the PFC circuit 112 stops operating, and the voltage V2 in the fixed fade period Tb reaches a value at which the first control power supply 101 becomes inoperable. descend.

Therefore, in the lighting system 11 of the present embodiment, when the voltages V1 and V2 drop below the voltage V3 when fading out the light output of the light source 12, the first control power supply 101 uses the voltage V3 to reduce the first control voltage Generate V11.

Furthermore, even if the dimming ratio of the light source 12 drops below the dimming lower limit due to the fade-out operation and the PFC circuit 112 stops operating, the capacitor 113 is still charged. The DC voltage Vd immediately after the PFC circuit 112 stops operating maintains the voltage target value. Therefore, during fade-out control, the first control power supply 101 can generate the first control voltage V11 using the voltage V3.

As a result, the lighting system 11 maintains the first control voltage V11 and the second control voltage V12 even if the voltages V1 and V2 drop and the PFC circuit 112 stops operating when the light output of the light source 12 is faded out. can be secured for the time being.

In this case, the capacitance C1 of the capacitor 113 is set to a value that satisfies Equation 1 below. Note that Vd1 is the voltage target value of the DC voltage Vd. Further, let Tb1 be the time length of the fixed fade period Tb. I1 and

C1≧I1·Tb1/Vd1 (Formula 1).

By setting the capacitance of the capacitor 113 to the capacitance C1 that satisfies Equation 1 above, the control circuit 1d can control the converter 1b over the fixed fade period Tb. That is, the control power supply 1h can maintain the first control voltage V11 at a value capable of driving the PFC circuit 112 and the converter 1b at least until the light source 12 is turned off during fade-out control. Furthermore, the control power supply 1h can maintain the second control voltage V12 at a value at which the control circuit 1d can operate at least until the light source 12 is turned off during fade-out control.

FIG. 6 shows waveforms of respective parts when the first control power supply 101 generates the first control voltage V11 and the second control voltage V12 using only the voltages V1 and V2 without using the voltage V3. FIG. 6 shows waveforms of the DC voltage Vd, the first control voltage V11, and the load current Io.

When the fade-out operation starts at time t10, the effective value of the phase control voltage Vb drops, and the DC voltage Vd and the first control voltage V11 also drop. From time t10 to time t11, the first control power supply 101 generates the first control voltage V11 using the voltage V1 or the voltage V2, and the first control voltage V11 operates the converter 1b and the control circuit 1d, respectively. value that can be set. Therefore, from time t10 to time t11, control circuit 1d can control converter 1b to gradually reduce load current Io. However, at time t11, the second control voltage V12 also drops due to the excessive drop in the first control voltage V11. As a result, the control circuit 1d stops operating, and the converter 1b stops operating. When the converter 1b stops operating, the load current Io abruptly drops to 0 (zero). As a result, the human eye perceives that the light source 12 has suddenly turned off.

On the other hand, FIG. 7 shows waveforms of respective parts when the first control power supply 101 generates the first control voltage V11 using the voltages V1, V2, and V3. FIG. 7 shows waveforms of the DC voltage Vd, the first control voltage V11, and the load current Io.

When the fade-out operation starts at time t10, the effective value of the phase control voltage Vb drops, and the DC voltage Vd and the first control voltage V11 also drop. The first control power supply 101 generates the first control voltage V11 using the voltage V1 or the voltage V2 from time t10 to time t11. Furthermore, after time t11, the first control power supply 101 generates the first control voltage V11 using the voltage V3. Therefore, even after time t11, the first control power supply 101 can generate the first control voltage V11, the second control power supply 102 can generate the second control voltage V12, and the control circuit 1d can control the converter 1b. After time t11, the control circuit 1d can also control the converter 1b to smoothly decrease the light output of the light source 12 until the light source 12 is turned off, thereby completing the fade-out control (time t12).

In other words, when the fade-out control is performed, the control power supply 1h can generate the first control voltage V11 and the second control voltage V12 from the DC voltage Vd for a predetermined period including the turn-off timing (time t12) of the light source 12. In the above equation 1, if "C1=I1·Tb1/Vd1", the control power supply 1h, when fade-out control is performed, changes from the DC voltage Vd to the first control voltage V11 and the first control voltage V11 over the fixed fade period Tb. 2 control voltage V12 can be generated. Further, in the above equation 1, if "C1>I1·Tb1/Vd1", then when the fade-out control is performed, the control power supply 1h is changed from the DC voltage Vd over the fixed fade period Tb+α (see FIG. 7). A first control voltage V11 and a second control voltage V12 can be generated.

As described above, when performing fade-out control, the control circuit 1d controls the converter 1b until the DC voltage Vd drops to the minimum voltage value VL1 (see FIG. 7) that enables lighting of the light source 12. to turn off the light source 12. Therefore, the lighting system 11 can smoothly change the light output when fading out the light output by phase control of the AC voltage Va.

Further, when the light output of the light source 12 is faded out by phase control of the AC voltage Va, the lighting system 11 maintains each value of the first control voltage V11 and the second control voltage V12 at least until the light source 12 is turned off. can. Therefore, the lighting system 11 can maintain the operation of the control circuit 1d at least until the light source 12 is turned off during fade-out control.

(Modification)
The phase reading circuit 1c may output the PWM signal as the conduction angle detection signal Sa without smoothing the PWM signal. In this case, the control circuit 1d preferably performs moving average processing when reading the conduction angle detection signal Sa.

Also, the phase reading circuit 1c may have two smoothing circuits with different time constants. In this case, the smoothing circuit with a large time constant can output the first conduction angle detection signal with low sensitivity to changes in the conduction angle θ to the control circuit 1d. Furthermore, a smoothing circuit with a small time constant can output a second conduction angle detection signal with high sensitivity to changes in the conduction angle θ to the control circuit 1d. By using the first conduction angle detection signal and the second conduction angle detection signal, the control circuit 1d can accurately control the converter 1b regardless of the magnitude of the conduction angle θ.

Note that each of the plurality of solid-state light-emitting elements included in the light source 12 is not limited to an LED, and may be another solid-state light-emitting element such as an organic EL (Organic Electro Luminescence, OEL) or an inorganic EL. Further, the number of solid-state light-emitting devices is not limited to plural, and may be one. The electrical connection relationship between the plurality of solid-state light emitting devices may be either serial connection or parallel connection, or may be a combination of serial connection and parallel connection.

Further, when the light source 12 has an incandescent lamp or the like, the control circuit 1d controls the dimming ratio of the light source 12 by controlling the magnitude of the output voltage of the converter 1b. In this case, the control parameter of converter 1b is the magnitude of the output voltage of converter 1b.

(lighting equipment)
FIG. 8 shows a lighting fixture B1 attached to a power supply duct 4 installed on a ceiling panel. The lighting fixture B1 includes a fixing portion 31 fixed to the power supply duct 4 and a housing 32 holding the light source 12 . The housing 32 has a cylindrical shape and emits light from the light source 12 from one surface in the axial direction. The lighting system 11 is housed in the fixed part 31 or the housing 32 . Also, the lighting system 11 may be housed separately in the fixed part 31 and the housing 32 . A phase control voltage Vb is input to the lighting system 11 of the lighting fixture B1 via a conductor (not shown) in the power supply duct 4 .

Furthermore, the housing 32 is rotatably connected to the fixed portion 31 . Specifically, the lighting fixture B<b>1 includes a first connecting portion 33 and a second connecting portion 34 . The first connecting portion 33 is connected to the fixed portion 31 so as to be rotatable around the vertical direction. The second connecting portion 34 connects the housing 32 to the first connecting portion 33 so as to be rotatable around the horizontal direction. That is, by rotating the first connecting portion 33 with respect to the fixed portion 31, the horizontal orientation of the housing 32 can be changed. Further, by rotating the housing 32 by the second connecting portion 34, the vertical orientation of the housing 32 can be changed.

As described above, the lighting system (11) of the first aspect according to the embodiment includes a DC power supply circuit (1a), a converter (1b), a phase reading circuit (1c), a control circuit (1d), and a control power supply (1h). A DC power supply circuit (1a) receives a phase control voltage (Vb), which is an AC voltage (Va) with a variable conduction angle (θ), and outputs a DC voltage (Vd). A converter (1b) receives a DC voltage (Vd) and supplies lighting power to a light source (12). A phase reading circuit (1c) detects the conduction angle (θ). A control circuit (1d) controls at least the converter (1b) according to the detected value of the conduction angle (θ), and adjusts the dimming ratio of the light source (12) to be lower as the detected value of the conduction angle (θ) is smaller. Light control. A control power supply (1h) generates control voltages (V11, V12) for operating the control circuit (1d). The control circuit (1d) controls the control voltages (V11, V12) at least until the light source (12) is extinguished while fade-out control for fading out the light output of the light source (12) is performed as dimming control. Circuit (1d) maintains an operable value.

The lighting system (11) described above maintains the operation of the control circuit (1d) at least until the light source (12) is extinguished when the light output of the light source (12) is faded out by phase control of the AC voltage (Va). can do.

Further, in the lighting system (11) of the second aspect according to the embodiment, in the first aspect, the DC power supply circuit (1a) has the capacitor (113), and the DC voltage (Vd) is applied to the capacitor (113 ). When the fade-out control is performed, the control power supply (1h) preferably generates control voltages (V11, V12) from the DC voltage (Vd) for a predetermined period (Tb) including the extinguishing timing of the light source (12).

The lighting system (11) described above can maintain the operation of the control circuit (1d) using the charging power of the capacitor (113) at least until the light source (12) is turned off during fade-out control.

Further, in the lighting system (11) of the third mode according to the embodiment, in the second mode, the predetermined period is the first period (Tb). A DC power supply circuit (1a) outputs a voltage (V2) different from a DC voltage (Vd) during operation. When fade-out control is performed, the control power supply (1h) generates control voltages (V11, V12) from the voltage (V2) during at least part of the second period (Ta) before the first period (Tb). is preferred.

The lighting system (11) described above can maintain the operation of the control circuit (1d) during the second period (Ta).

Further, in the lighting system (11) of the fourth mode according to the embodiment, in the third mode, when the fade-out control is performed, the control power source (1h) changes the phase in part of the second period (Ta). It is preferable to generate the control voltages (V11, V12) from the control voltage (Vb).

The lighting system (11) described above can maintain the operation of the control circuit (1d) during the second period (Ta).

Further, in the lighting system (11) of the fifth aspect according to the embodiment, in any one of the first to fourth aspects, the control circuit (1d) controls the DC voltage (Vd) when performing fade-out control. However, it is preferable to control the converter (1b) to turn off the light source (12) before the voltage drops to the minimum voltage value (VL1) that enables lighting of the light source (12).

The lighting system (11) described above can smoothly change the light output when the light output is faded out by phase control of the AC voltage (Va). Therefore, the lighting system (11) can make the human eye feel that the light output has decreased smoothly without discomfort until the light source (12) is extinguished during the fade-out operation.

Further, the lighting control system (A1) of the sixth aspect according to the embodiment includes the lighting system (11) of any one of the first to fifth aspects connected to an AC power supply (9) and a dimmer ( 2) with a series circuit. A dimmer (2) outputs a phase control voltage (Vb), which is an AC voltage (Va) with a variable conduction angle (θ), to a lighting system (11).

When the light output of the light source (12) is faded out by phase control of the AC voltage (Va), the lighting control system (A1) described above operates the control circuit (1d) at least until the light source (12) is extinguished. can be maintained.

A lighting fixture (B1) of a seventh aspect according to the embodiment includes the lighting system (11) of any one of the first to fifth aspects and a light source supplied with lighting power from the lighting system (11). (12) and a housing (32) in which at least the light source (12) is supported.

The lighting fixture (B1) described above maintains the operation of the control circuit (1d) at least until the light source (12) is extinguished when the light output of the light source (12) is faded out by phase control of the AC voltage (Va). can do.

Also, the above-described embodiment and modifications are examples. Therefore, the present invention is not limited to the above-described embodiments and modifications, and other than the embodiments and modifications, as long as they do not deviate from the technical idea of the present invention. Of course, various modifications are possible depending on the requirements.

Reference Signs List 1 lighting device 2 dimmer 9 AC power supply 11 lighting system 12 light source 32 housing 113 capacitor 1a DC power supply circuit 1b converter 1c phase reading circuit 1d control circuit 1h control power supply A1 lighting control system B1 lighting fixture θ conduction angle V11 first control Voltage (control voltage)
V12 second control voltage (control voltage)
Va: AC voltage Vb: Phase control voltage Vd: DC voltage VL1: Minimum voltage value Ta: Follow-up fade period (second period)
Tb fixed fade period (first period)

Claims (6)

a DC power supply circuit that receives a phase control voltage, which is an AC voltage with a variable conduction angle, and outputs a DC voltage;
a converter that receives the DC voltage and supplies lighting power to the light source;
a phase reading circuit that detects the conduction angle;
a control circuit that controls at least the converter according to the detected value of the conduction angle, and performs dimming control such that the smaller the detected value of the conduction angle, the lower the dimming ratio of the light source;
a control power supply that generates a control voltage for operating the control circuit;
The control power supply maintains the control voltage at a value at which the control circuit can operate at least until the light source is turned off, while fade-out control for fading out the light output of the light source is performed as the dimming control,
The DC power supply circuit has a capacitor and causes the capacitor to generate the DC voltage,
When the fade-out control is performed, the control power supply generates the control voltage from the DC voltage for a predetermined period including a timing when the light source is turned off.
lighting system. The predetermined period is a first period,
The DC power supply circuit outputs a voltage different from the DC voltage during operation,
When the fade-out control is performed, the control power supply generates the control voltage from the voltage during at least part of a second period prior to the first period.
The lighting system according to claim 1. The control power supply generates the control voltage from the phase control voltage during a part of the second period when the fade-out control is performed.
The lighting system according to claim 2. The control circuit is
When performing the fade-out control, the converter is controlled to turn off the light source before the DC voltage drops to a minimum voltage value that enables lighting of the light source.
The lighting system according to any one of claims 1 to 3. A series circuit of the lighting system of any one of claims 1 to 4 connected to an AC power supply and a dimmer,
The dimmer outputs a phase control voltage, which is an AC voltage with a variable conduction angle, to the lighting system.
lighting control system. A lighting system according to any one of claims 1 to 4;
a light source supplied with the lighting power from the lighting system;
a housing in which at least the light source is supported
lighting equipment.

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