JP7108927B2 - Lighting device, light emitting device and lighting equipment - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a lighting device, a light-emitting device, and a lighting fixture, and more particularly to a lighting device that lights a solid-state light source, a light-emitting device that includes the lighting device and the solid-state light source, and a lighting fixture that includes the light-emitting device.

Conventionally, there has been provided a lighting device that rectifies a sinusoidal AC voltage supplied from a commercial AC power supply and directly applies it to a solid-state light source such as an LED (Light Emitting Diode) to light the solid-state light source. In such a lighting device, a smoothing capacitor may be electrically connected in parallel with the solid-state light source in order to suppress fluctuations (ripples) in the amount of light from the solid-state light source due to changes in the AC voltage. Reference 1).

JP 2016-207546 A

However, when a smoothing capacitor is electrically connected in parallel to the solid-state light source, the smoothing capacitor is charged from the time the AC power is turned on, and the voltage across the capacitor reaches the lighting start voltage of the solid-state light source. The solid-state light source does not turn on until In other words, in the above-described conventional lighting device, the time (startup time) from the time when the AC power supply is turned on until the solid-state light source is lit is considerably longer than when there is no smoothing capacitor.

An object of the present disclosure is to provide a lighting device, a light-emitting device, and a lighting fixture that can shorten the time required from turning on an AC power supply to starting lighting of a solid-state light source while suppressing fluctuations in the amount of light from the solid-state light source. .

A lighting device according to an aspect of the present disclosure includes a rectifier circuit that rectifies an alternating voltage, and a capacitor that is electrically connected in parallel with a solid-state light source and to which a pulsating current output from the rectifier circuit is applied. . The lighting device controls a voltage detection circuit that detects a voltage across the capacitor, a current adjustment circuit that adjusts a load current flowing from the rectifier circuit to at least one of the solid-state light source and the capacitor, and the current adjustment circuit. and a control circuit for increasing and decreasing the load current. When the AC voltage starts to be input to the rectifier circuit, the control circuit causes the capacitor to pass a load current that is larger than the load current that flows to the solid-state light source in a steady state , and the voltage detection circuit The current adjustment circuit is controlled to reduce the load current before the detected voltage across the capacitor reaches the lighting start voltage of the solid-state light source .

A light-emitting device according to an aspect of the present disclosure includes the lighting device and a solid-state light source that is lit by the lighting device.

A lighting fixture according to an aspect of the present disclosure includes the light emitting device and a fixture body that supports the light emitting device.

The lighting device, light-emitting device, and lighting fixture according to the present disclosure have the effect of reducing the time required from turning on the AC power supply to starting lighting of the solid-state light source while suppressing fluctuations in the amount of light from the solid-state light source.

1 is a perspective view of a lighting fixture according to an embodiment of the present disclosure; FIG. FIG. 2A is a front view of the same lighting fixture with a part thereof omitted. FIG. 2B is a bottom view of the same lighting fixture with a part thereof omitted. FIG. 3 is a partial cross-sectional view of the same lighting fixture. FIG. 4 is a circuit diagram of a lighting device according to an embodiment of the present disclosure; FIG. 5 is a waveform diagram for explaining the steady-state operation of the same lighting device. FIG. 6A is an explanatory diagram of the operation of the lighting device in section M0. FIG. 6B is an explanatory diagram of the operation of the lighting device in section M1. FIG. 6C is an explanatory diagram of the operation of the lighting device in section M2. FIG. 6D is an explanatory diagram of the operation of the lighting device in section M3. FIG. 7 is a waveform diagram for explaining the operation of the lighting device when power is turned on. FIG. 8 is a waveform diagram for explaining the operation of the lighting device when power is turned on. FIG. 9A is a waveform diagram for explaining the operation of the lighting device when power is turned on. FIG. 9B is a waveform diagram for explaining the operation of the lighting device of the comparative example when the power is turned on. FIG. 10 is a circuit diagram of a modification of the above lighting device.

Hereinafter, lighting devices, light emitting devices, and lighting fixtures according to embodiments of the present disclosure will be described in detail with reference to the drawings. However, each drawing described in the following embodiments is a schematic drawing, and the ratio of the size and thickness of each component does not necessarily reflect the actual dimensional ratio. Note that the configurations described in the following embodiments are merely examples of the present disclosure. The present disclosure 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 disclosure can be achieved.

First, a lighting fixture 1 according to an embodiment of the present disclosure will be described. As shown in FIGS. 1 to 3, the lighting fixture 1 includes a fixture body 10 formed in the shape of a long rectangular parallelepiped. A light-emitting device 2 according to an embodiment of the present disclosure is housed inside the fixture body 10 . The light-emitting device 2 has a plurality of LEDs 3 corresponding to solid-state light sources and a lighting device 4 according to the embodiment of the present disclosure (see FIG. 3). In the following description, unless otherwise specified, the up/down, front/rear, and left/right directions in FIG.

Each of the plurality of LEDs 3 is, for example, a white LED for illumination. The plurality of LEDs 3 are arranged in a row along the longitudinal direction of the printed wiring board 30 in a region on the right side of the center of the printed wiring board 30 in the short direction on the surface (upper surface) of the long rectangular printed wiring board 30 . Moreover, they are mounted at regular intervals (see FIG. 3). The plurality of LEDs 3 are electrically connected (for example, serially connected or series-parallelly connected) by printed wiring formed on the surface of the printed wiring board 30 .

The lighting device 4 is formed by mounting various electronic components, which will be described later, on the surface of the printed wiring board 30 on which the plurality of LEDs 3 are mounted, in an area on the left side of the center of the printed wiring board 30 in the width direction. (See Figure 3). However, the lighting device 4 may be formed by mounting various electronic components on a printed wiring board different from the printed wiring board 30 on which the plurality of LEDs 3 are mounted.

The fixture body 10 has a right side facing the plurality of LEDs 3 and a right end portion of the upper surface made of translucent synthetic resin (e.g., polycarbonate resin), and other portions are made of non-translucent synthetic resin (e.g., , polybutylene terephthalate resin). That is, the light emitted from (the plurality of LEDs 3 of) the light emitting device 2 is irradiated into the space through the right end portion of the right side surface and the top surface of the fixture main body 10 . The device body 10 is attached to a construction material such as a wall or ceiling by means of a metal mounting plate 7 (see FIG. 3).

Next, the circuit configuration of the lighting device 4 according to the embodiment will be described. The lighting device 4, as shown in FIG. 4, includes a rectifying circuit 40, a first constant current circuit 41, a second constant current circuit 42, a control circuit 43, a voltage detection circuit 44, and a capacitor C1. The lighting device 4 further includes a bleeder circuit 45 and an input voltage detection circuit 46 . The capacitor C1 is electrically connected in parallel with an LED module 31, which is composed of a plurality of LEDs 3 electrically connected in series. In the following description, among the two LEDs 3 at both ends of the plurality of LEDs 3 forming the LED module 31, the anode of the LED 3 at one end that is not electrically connected to the cathode of the adjacent LED 3 is referred to as the LED module 31. is called the positive electrode of Among the two LEDs 3 at both ends of the plurality of LEDs 3 , the cathode of the LED 3 at the other end that is not electrically connected to the anode of the adjacent LED 3 is called the negative electrode of the LED module 31 .

The rectifier circuit 40 is composed of a diode bridge circuit. The AC power supply 8 and the dimmer 9 are electrically connected in series between the AC input terminals of the rectifier circuit 40 . The rectifier circuit 40 performs full-wave rectification of an AC voltage (sinusoidal AC voltage) input between AC input terminals, and outputs a rectified pulsating current voltage between pulsating current output terminals.

The dimmer 9 phase-controls the AC voltage supplied from the AC power supply 8 to the lighting device 4 using, for example, a bidirectional three-terminal thyristor (also called a triac). The dimmer 9 has, for example, a rotary or slide type operation handle, and phase-controls the AC voltage at a phase angle corresponding to the rotation angle or movement distance of the operation handle. The rotation angle (for example, any angle from 0° to 300°) or movement distance of the operation handle and the dimming level of the LED module 31 are associated on a one-to-one basis. The dimming level represents the ratio of the current flowing through the LED module 31 when the amount of light when the rated current is flowing through the LED module 31 is taken as 100%.

The positive electrode of the LED module 31 is electrically connected to the pulsating current output terminal on the high potential side of the rectifier circuit 40 via the diode D1. A capacitor C1 and a voltage detection circuit 44 are electrically connected in parallel across the LED module 31 . Capacitor C1 is, for example, an electrolytic capacitor. However, the capacitor C1 may be a film capacitor or the like. Further, the capacitor C1 does not have to be composed of one electrolytic capacitor, one fill capacitor, or the like. The capacitor C1 may be configured by electrically connecting a plurality of electrolytic capacitors or a plurality of film capacitors in parallel, for example. However, it is preferable that the capacitor C1 is electrically connected in parallel with a resistor for discharging the charge of the capacitor C1 when the power supply from the AC power supply 8 is stopped.

A voltage detection circuit 44 detects a voltage VC1 across the capacitor C1. The voltage detection circuit 44 outputs a high-level detection signal to the control circuit 43 when the voltage VC1 between both ends is less than the threshold voltage Vth, and outputs a low-level detection signal when the voltage VC1 between both ends is equal to or higher than the threshold voltage Vth. is output to the control circuit 43 . However, the voltage detection circuit 44 outputs a low-level detection signal to the control circuit 43 when the voltage VC1 between both ends is less than the threshold voltage Vth, and outputs a high-level detection signal when the voltage VC1 between both ends is equal to or higher than the threshold voltage Vth. A detection signal may be output to the control circuit 43 .

A first constant current circuit 41 corresponding to a current adjusting circuit has a transistor Q1, an operational amplifier 410, and a resistor 411. FIG. The transistor Q1 is an enhancement type N-channel MOSFET (Metal Oxide Semiconductor Field Effect Transistor). The drain of transistor Q1 is electrically connected to the negative electrode of LED module 31 . The source of transistor Q1 is electrically connected through resistor 411 to ground. The gate of transistor Q1 is electrically connected to the output terminal of operational amplifier 410 . An inverting input terminal (minus terminal) of the operational amplifier 410 is electrically connected to the source of the transistor Q1. A non-inverting input terminal (plus terminal) of the operational amplifier 410 is electrically connected to the control circuit 43 . The operational amplifier 410 adjusts the output voltage so that the voltage across the resistor 411, which is proportional to the drain current of the transistor Q1, matches the control voltage V1. For example, if the drain current of the transistor Q1 increases, the output voltage of the operational amplifier 410 will decrease, and if the drain current of the transistor Q1 decreases, the output voltage of the operational amplifier 410 will increase. In other words, the first constant current circuit 41 makes the drain current of the transistor Q1 (the current flowing through the LED module 31 or the capacitor C1) equal to the target value corresponding to the control voltage V1 to make the current constant.

Here, the drain of transistor Q1 is electrically connected to the anode of diode D2. The cathode of diode D2 is electrically connected to the positive electrode of capacitor C3, which is an electrolytic capacitor, and the anode of diode D3. The cathode of diode D3 is electrically connected to the positive electrode of LED module 31 . The negative terminal of capacitor C3 is electrically connected to the cathode of diode D4 and the anode of diode D5. The anode of diode D4 is electrically connected to ground.

The second constant current circuit 42 has a transistor Q<b>2 , an operational amplifier 420 and a resistor 421 . Transistor Q2 is an enhancement type N-channel MOSFET. The drain of transistor Q2 is electrically connected to the cathode of diode D5. The source of the transistor Q2 is electrically connected to the ground through the resistor 421 and the resistor 411 of the first constant current circuit 41. The gate of transistor Q 2 is electrically connected to the output terminal of operational amplifier 420 . The inverting input terminal (minus terminal) of operational amplifier 420 is electrically connected to the source of transistor Q2. The non-inverting input terminal (plus terminal) of the operational amplifier 420 is electrically connected to the control circuit 43 together with the non-inverting input terminal of the operational amplifier 410 of the first constant current circuit 41 . Therefore, the control voltage V 1 output from the control circuit 43 is input to the non-inverting input terminal of the operational amplifier 420 . The operational amplifier 420 adjusts the output voltage so that the voltage across the resistors 411 and 421, which is proportional to the drain current of the transistor Q2, matches the control voltage V1. For example, if the drain current of transistor Q2 increases, the output voltage of operational amplifier 420 decreases, and if the drain current of transistor Q2 decreases, the output voltage of operational amplifier 420 increases. That is, the second constant current circuit 42 makes the drain current of the transistor Q2 (the current flowing through the LED module 31) equal to the target value corresponding to the control voltage V1, thereby making the current constant.

The bleeder circuit 45 has a transistor Q3, a drive circuit 450, and two resistors 451,452. Transistor Q3 is an enhancement type N-channel MOSFET. The drain of the transistor Q3 is electrically connected via a resistor 451 to the pulsating current output terminal on the high potential side of the rectifier circuit 40 and the anode of the diode D1. The source of the transistor Q3 is electrically connected to the ground via a control power supply capacitor C2. A gate of transistor Q3 is electrically connected to drive circuit 450 . Resistor 452 is electrically connected between capacitor C2 and the negative input terminal of drive circuit 450 . Drive circuit 450 adjusts the output voltage so that the voltage across resistor 452, which is proportional to the drain current of transistor Q3, matches the target value. For example, if the drain current of the transistor Q3 increases, the output voltage output from the driving circuit 450 to the gate of the transistor Q3 decreases, and if the drain current of the transistor Q3 decreases, the output voltage of the driving circuit 450 increases. . That is, the bleeder circuit 45 makes the drain current (bleeder current) of the transistor Q3 constant.

Capacitor C2 generates control power supply voltage Vcc from the bleeder current flowing through bleeder circuit 45 . The control power supply voltage Vcc is supplied to the operational amplifier 410 of the first constant current circuit 41 , the operational amplifier 420 of the second constant current circuit 42 and the control circuit 43 . The operational amplifier 410 of the first constant current circuit 41, the operational amplifier 420 of the second constant current circuit 42, and the control circuit 43 are supplied with the control power supply voltage Vcc to operate. However, the lighting device 4 may include a power supply circuit that generates the control power supply voltage Vcc instead of the capacitor C2.

The input voltage detection circuit 46 outputs the input detection voltage Vk of the upper limit value to the control circuit 43 when the input voltage is not phase-controlled. Further, the input voltage detection circuit 46 controls the input detection voltage Vk (<detection voltage of the upper limit value) proportional to the phase angle of the input voltage (also called control lead angle) when the input voltage is phase-controlled. 43.

Control circuit 43 is preferably configured by a computer system. A computer system is mainly composed of a processor and a memory as hardware. The function of the control circuit 43 in the present disclosure is realized by the processor executing a program recorded in the memory of the computer system. The program may be recorded in advance in the memory of the computer system, may be provided through an electric communication line, or may be recorded in a non-temporary recording medium such as a computer system-readable memory card, optical disk, or hard disk drive. may be provided. A processor in a computer system consists of one or more electronic circuits including semiconductor integrated circuits (ICs) or large scale integrated circuits (LSIs). The integrated circuit such as IC or LSI referred to here is called differently depending on the degree of integration, and includes integrated circuits called system LSI, VLSI (Very Large Scale Integration), or ULSI (Ultra Large Scale Integration). Furthermore, an FPGA (Field-Programmable Gate Array), which is programmed after the LSI is manufactured, or a logic device capable of reconfiguring the bonding relationship inside the LSI or reconfiguring the circuit partitions inside the LSI, shall also be adopted as the processor. can be done. A plurality of electronic circuits may be integrated into one chip, or may be distributed over a plurality of chips. A plurality of chips may be integrated in one device, or may be distributed in a plurality of devices. A computer system, as used herein, includes a microcontroller having one or more processors and one or more memories. Accordingly, the microcontroller also consists of one or more electronic circuits including semiconductor integrated circuits or large scale integrated circuits.

The control circuit 43 A/D-converts the input detection voltage Vk inputted from the input voltage detection circuit 46 and fetches it. The control circuit 43 also receives a detection signal (high/low binary signal) output from the voltage detection circuit 44 . Furthermore, the control circuit 43 outputs a control voltage V1 and adjusts the control voltage V1 according to the input detection voltage Vk and the detection signal.

Next, the normal operation of the lighting device 4 will be described with reference to FIGS. 5 and 6. FIG. In this embodiment, the term "steady state" means that when the AC power supply 8 is turned on and the AC voltage is input to the lighting device 4, the LED module 31 lights up and the LED module 31 emits light stably. It refers to the state in which

The first stage in FIG. 5 shows the waveform of two cycles of the pulsating voltage Va output from the rectifier circuit 40 (one cycle of the AC voltage input to the rectifier circuit 40: 0 [rad] to 2π [rad]). ing. The second row in FIG. 5 shows the waveform of the current Iin output from the rectifier circuit 40 within two periods of the pulsating voltage Va. 5 shows the voltage VC3 across the capacitor C3 of the lighting device 4. FIG. Furthermore, the fourth row in FIG. 5 shows the forward current IF flowing through the LED module 31 .

FIG. 6A shows the path and direction of the current flowing through the lighting device 4 in the section M0 where the phase of the pulsating voltage Va straddles nπ [rad] (n: 0, 1, 2). FIG. 6B shows the path and direction of the current flowing through the lighting device 4 in the section M1 in which the phase of the pulsating voltage Va follows the section M0. FIG. 6C shows the path and direction of the current flowing through the lighting device 4 in the section M2 in which the phase of the pulsating voltage Va follows the section M1. FIG. 6D shows the path and direction of the current flowing through the lighting device 4 in the section M3 following the section M2, where the phase of the pulsating voltage Va crosses over nπ/2 [rad] (n: 1, 2). . However, in FIGS. 6A to 6D, illustration of some circuit components (for example, capacitor C1, etc.) constituting the lighting device 4 is omitted.

In a section M0 from when the pulsating current Va passes through zero crossing to when the bleeder circuit 45 starts operating, the charge charged in the capacitor C3 in the section M3 is discharged, and a forward current IF flows through the LED module 31. . The forward current IF in section M0 flows through the path of capacitor C3, diode D3, LED module 31, first constant current circuit 41 (transistor Q1), diode D4, and capacitor C3 (see FIG. 6A). The first constant current circuit 41 operates to constant the forward current IF. Therefore, the LED module 31 is illuminated with a constant brightness (amount of light) due to the constant forward current IF flowing. Although the bleeder circuit 45 stops operating in the section M0, the first constant current circuit 41 and the control circuit 43 operate with the control power supply voltage Vcc supplied by the discharged charge of the capacitor C2.

When the pulsating voltage Va rises and exceeds the operation start voltage of the bleeder circuit 45, the bleeder circuit 45 operates and the bleeder current Ib flows (see FIG. 6B). In addition, the bleeder circuit 45 flows a bleeder current Ib of a value (for example, 20 mA to 40 mA) larger than the current (about 10 mA) required for self-holding of the bidirectional three-terminal thyristor (triac) of the dimmer 9. is preferred. Also in the section M1, the discharge charge of the capacitor C3 and the action of the first constant current circuit 41 cause the forward current IF to continue to flow through the LED module 31 . Therefore, the LED module 31 is illuminated with a constant brightness (amount of light) due to the constant forward current IF flowing even in the section M1.

When the pulsating current voltage Va rises to the lighting start voltage Vst of the LED module 31 (section M2), the current output from the rectifier circuit 40 flows into the LED module 31 as the forward current IF (see FIG. 6C). The forward current IF is made constant by the first constant current circuit 41 . Therefore, the LED module 31 is illuminated with a constant brightness (amount of light) due to the constant forward current IF flowing even in the section M2.

When the pulsating voltage Va further increases and approaches the peak value (section M3), the diode D2 becomes conductive. When diode D2 conducts, forward current IF flows through diode D2 to capacitor C3, which charges capacitor C3 (see FIG. 6D). The forward current IF flowing through the capacitor C3 is made constant by the second constant current circuit 42 . The first constant current circuit 41 is stopped while the second constant current circuit 42 is operating.

When the pulsating voltage Va passes the peak value and falls below the voltage VC3 across the capacitor C3 (section M2), the second constant current circuit 42 stops, the first constant current circuit 41 operates, and the rectifier circuit 40 outputs current flows through the LED module 31 as a forward current IF (see FIG. 6C).

When the pulsating current voltage Va further decreases and falls below the lighting start voltage Vst of the LED module 31 (section M1), the charge in the capacitor C3 is discharged and the forward current IF flows through the LED module 31 . The forward current IF is made constant by the first constant current circuit 41 (see FIG. 6B).

The lighting device 4 repeats the operation of each section M0, section M1, section M2, section M3, section M2, and section M1 according to the phase of the pulsating voltage Va, thereby turning the LED module 31 forward. A current IF is passed to light the LED module 31 . Moreover, in the lighting device 4 , the capacitor C<b>1 is electrically connected in parallel with the LED module 31 .

Next, the operation of the lighting device 4 when the AC voltage input from the AC power supply 8 to the lighting device 4 is phase-controlled by the dimmer 9 will be described.

The control circuit 43 A/D-converts the pulsating current voltage Va output from the rectifier circuit 40, and detects the phase angle of the phase-controlled AC voltage according to the voltage data taken in as a digital value. Further, the control circuit 43 determines a target value (control voltage V1) of the forward current IF corresponding to the detected phase angle. For example, the control circuit 43 stores the correspondence between the phase angle and the target value of the forward current IF as a data table, and refers to the data table to obtain the target value of the forward current IF corresponding to the detected phase angle. should be determined. Then, the control circuit 43 outputs the control voltage V1 corresponding to the determined target value to the first constant current circuit 41 and the second constant current circuit 42 . As a result, the lighting device 4 can dim the LED module 31 by causing the forward current IF corresponding to the phase angle of the phase-controlled AC voltage to flow through the LED module 31 .

Next, the operation of the lighting device 4 when the AC power supply 8 is turned on will be described with reference to the time chart of FIG. 7 and the waveform diagram of FIG. The top row of FIG. 7 shows the waveform of the AC voltage (input voltage of the lighting device 4) Vin of the AC power supply 8, and the second row from the top of FIG. 7 shows the waveform of the input detection voltage Vk of the input voltage detection circuit 46. showing. The third row from the top in FIG. 7 shows the waveform of the input detection voltage Vm after filtering the input detection voltage Vk with a low-pass filter in the control circuit 43, and the fourth row from the top in FIG. 7 shows the waveform of the control voltage V1. Waveforms are shown. The third row from the bottom in FIG. 7 shows the voltage VC1 across the capacitor C1 connected in parallel with the LED module 31, and the second row from the bottom in FIG. 7 shows the waveform of the detection signal output from the voltage detection circuit 44. 7 shows the waveform of the forward current IF.

When the AC power supply 8 is turned on at time t=t0 and the AC voltage Vin is input to the lighting device 4, the control circuit 43 starts operating. When the AC voltage Vin is input, the input detection voltage Vk of the input voltage detection circuit 46 increases, and the input detection voltage Vm after filtering in the control circuit 43 also increases. However, the control circuit 43 does not output the control voltage V1 until the input detection voltage Vm after filtering reaches a predetermined operation start voltage Vma (for example, Vma≈5V). Therefore, since the first constant current circuit 41 does not operate, the capacitor C1 is not charged. As a result, the voltage detection circuit 44 outputs a high-level detection signal (see FIG. 7).

When the input detection voltage Vm reaches the operation start voltage Vma (time t=t1), the control circuit 43 starts outputting the control voltage V1. However, the control circuit 43 operates so as to shorten the time until the voltage VC1 across the capacitor C1 reaches the lighting start voltage Vst of the LED module 31 when starting the operation from the stopped state. Specifically, the control circuit 43 changes the current (load current) that the first constant current circuit 41 flows through the capacitor C1 to the forward current IF that flows through the LED module 31 during normal operation by making the control voltage V1 higher than that during normal operation. increase more than

When the voltage VC1 across the capacitor C1 rises and reaches the threshold voltage Vth, the voltage detection circuit 44 outputs a low-level detection signal to the control circuit 43 (time t=t2). When the low-level detection signal is input, the control circuit 43 lowers the control voltage V1 to the normal voltage. As a result, the current flowing through the capacitor C1 from the first constant current circuit 41 is reduced to the steady-state level, and the rising speed of the voltage VC1 across the capacitor C1 is also reduced. After that, when the voltage VC1 across the capacitor C1 reaches the lighting start voltage Vst, the current flowing through the capacitor C1 begins to flow to the LED module 31 as the forward current IF, and the LED module 31 lights up (time t=t3).

Here, when the control circuit 43 starts to operate from the stopped state, if the control voltage V1 is set to the same voltage as in the steady state, the voltage VC1 across the capacitor C1 rises with a slope from time t=t2 to t3 in FIG. do. Therefore, the time required for the voltage VC1 across the capacitor C1 to reach the lighting start voltage Vst is greatly extended.

On the other hand, in the lighting device 4, when the AC voltage Vin starts to be input to the rectifier circuit 40, the control circuit 43 causes a load current larger than the forward current IF to flow through the LED module 31 to flow through the capacitor C1. , the first constant current circuit 41 is controlled. That is, the lighting device 4 can reduce the time required for the voltage VC1 across the capacitor C1 to reach the lighting start voltage Vst, compared to when the load current is not increased. As a result, the lighting device 4 can shorten the period from turning on the AC power supply 8 to lighting the LED module 31 while suppressing fluctuations in the amount of light of the LED module 31 by the capacitor C1.

Further, the control circuit 43 lowers the control voltage V1 to the normal voltage before the voltage VC1 across the capacitor C1 reaches the lighting start voltage Vst. As a result, the lighting device 4 prevents a forward current IF larger than that in the normal state from flowing when the LED module 31 starts lighting, that is, prevents the LED module 31 from instantaneously emitting light with higher luminance than in the normal state. can be done.

It is preferable that the control circuit 43 lowers the control voltage V1 to the normal voltage to reduce the load current when the time elapsed from turning on the AC power supply 8 reaches a predetermined stop time. That is, if the voltage VC1 across the capacitor C1 does not rise to the threshold voltage Vth for some reason, the control circuit 43 forcibly reduces the load current, thereby preventing the occurrence of the problem.

Here, when the AC voltage Vin is phase-controlled when the AC power supply 8 is turned on, the forward current IF flowing through the LED module 31 is smaller than when the AC voltage Vin is not phase-controlled. Therefore, if the control circuit 43 does not increase the load current flowing through the capacitor C1 when the AC voltage Vin starts to be input to the rectifier circuit 40, the rate of increase of the voltage VC1 across the capacitor C1 will further slow down, causing the LED The delay time until the module 31 lights up is also longer. Therefore, in the lighting device 4, it is possible to shorten the period from turning on the AC power supply 8 to lighting the LED module 31, especially when the AC voltage Vin is phase-controlled when the AC power supply 8 is turned on.

By the way, in the control circuit 43, by filtering high-frequency components contained in the input detection voltage Vk with a low-pass filter, erroneous detection of the phase angle due to fluctuations in the pulsating current voltage Va due to noise is prevented. . Specifically, the control circuit 43 calculates voltage data y(i) after filtering from voltage data x(i) of the A/D converted pulsating current Va by the following equation (1). However, τ is a time constant.

y(i)=x(i-1)+(x(i)-x(i-1))/τ...Equation (1)
That is, in order to prevent erroneous detection of the phase angle, it is preferable to lower the cutoff frequency of the low-pass filter, in other words, to increase the time constant τ in the above equation (1).

On the other hand, when the AC power supply 8 is turned on, the larger the time constant τ of the low-pass filter, the later the timing at which the control circuit 43 outputs the control voltage V1 and the first constant current circuit 41 starts to flow the load current. .

Therefore, it is preferable that the control circuit 43 makes the time constant τ of the low-pass filter smaller than the time constant τ in the steady state when starting the operation from the stopped state. For example, in the control circuit 43, when the time constant τ of the low-pass filter in the steady state is set to 500 milliseconds, the time constant τ when starting the operation from the stopped state may be set to 20 milliseconds. FIG. 9B shows waveforms of the control voltage V1 and the forward current IF when the control circuit 43 starts operating from the stop state with the time constant τ of the low-pass filter fixed at 500 milliseconds. On the other hand, FIG. 9A shows waveforms of the control voltage V1 and the forward current IF when the control circuit 43 starts operating from the stop state in a state where the time constant τ of the low-pass filter is switched from 500 ms to 20 ms. is shown. However, times t=t0, t1, and t2 in FIGS. 9A and 9B are the time when the AC power supply 8 is turned on, the time when the input detection voltage Vm reaches the predetermined operation start voltage Vma, and the voltage VC1 across the capacitor C1. is the time when reaches the threshold voltage Vth. As is clear from FIGS. 9A and 9B, the lighting device 4 makes the time constant τ of the low-pass filter of the control circuit 43 smaller than the time constant τ in the steady state, so that the LED module 31 is It is possible to shorten the period until lighting.

By the way, the control circuit 43 may switch the time constant τ of the low-pass filter to a plurality of stages of three or more stages. For example, the control circuit 43 may switch the time constant τ of the low-pass filter among three stages of 10 milliseconds, 20 milliseconds, and 500 milliseconds. That is, the control circuit 43 sets the time constant τ to 10 milliseconds when starting the operation from the stopped state, and switches the time constant τ to 20 milliseconds when the input detection voltage Vm reaches the predetermined operation start voltage Vma. Just do it. Further, the control circuit 43 may switch the time constant τ to 500 milliseconds when the voltage VC1 between both ends reaches the lighting start voltage Vst. If the control circuit 43 switches the time constant τ of the low-pass filter in three or more stages in this manner, the period from turning on the AC power supply 8 to turning on the LED module 31 can be further shortened.

Next, modified examples of the lighting device 4 according to the embodiment will be described. As shown in FIG. 10, the lighting device 4 of the modified example additionally includes a third constant current circuit 47 and a capacitor C4. The capacitor C4 is electrically connected in parallel with the second LED module 32 . The second LED module 32 is configured by electrically connecting a plurality of LEDs 3 in series in the forward direction, similar to the LED module 31 (hereinafter sometimes referred to as the first LED module 31). In the following description, among the two LEDs 3 at both ends of the plurality of LEDs 3 that constitute the second LED module 32, the anode of the LED 3 at one end that is not electrically connected to the cathode of the adjacent LED 3 is It is called the positive electrode of the second LED module 32 . Among the two LEDs 3 at both ends of the plurality of LEDs 3 , the cathode of the LED 3 at the other end that is not electrically connected to the anode of the adjacent LED 3 is called the negative electrode of the second LED module 32 .

Capacitor C4 is, for example, an electrolytic capacitor. However, the capacitor C4 may be a film capacitor or the like. Further, the capacitor C4 may not be composed of one electrolytic capacitor, one fill capacitor, or the like. The capacitor C4 may be configured by electrically connecting a plurality of electrolytic capacitors or a plurality of film capacitors in parallel, for example. However, it is preferable that the capacitor C4 is electrically connected in parallel with a resistor for discharging the charge of the capacitor C4 when the power supply from the AC power supply 8 is stopped. The positive electrode of the second LED module 32 and one end (one end on the high potential side) of the capacitor C4 are electrically connected to the negative electrode of the first LED module 31 .

The third constant current circuit 47 has a transistor Q 4 , an operational amplifier 470 and a resistor 471 . Transistor Q4 is an enhancement type N-channel MOSFET. The drain of transistor Q4 is electrically connected to the negative terminal of the second LED module 32; The source of transistor Q4 is electrically connected through resistor 471 and resistor 411 to ground. The gate of transistor Q 4 is electrically connected to the output terminal of operational amplifier 470 . The inverting input terminal of operational amplifier 470 is electrically connected to the source of transistor Q4. A non-inverting input terminal of the operational amplifier 470 is electrically connected to the control circuit 43 . The operational amplifier 470 adjusts the output voltage so that the voltage across the resistors 471 and 411, which is proportional to the drain current of the transistor Q4, matches the control voltage V1. For example, if the drain current of transistor Q4 increases, the output voltage of operational amplifier 470 decreases, and if the drain current of transistor Q4 decreases, the output voltage of operational amplifier 470 increases. That is, the third constant current circuit 47 makes the drain current of the transistor Q4 (the forward current flowing through the second LED module 32) equal to the target value corresponding to the control voltage V1 to make the current constant.

The lighting device 4 of the modification has a period in which only the first LED module 31 is lit and a period in which the first LED module 31 and the second LED module are lit in one cycle of the pulsating voltage Va (half cycle of the AC voltage Vin). 32 is lit. Also in the lighting device 4 of the modified example, the control circuit 43 shortens the time until the voltage VC1 across the capacitor C1 reaches the lighting start voltage Vst of the first LED module 31 when the operation is started from the stopped state. works like As a result, the lighting device 4 of the modified example can shorten the period from turning on the AC power supply 8 to lighting the LED module 31 .

As described above, the lighting device (4) according to the first aspect is electrically connected in parallel with the rectifier circuit (40) that rectifies the AC voltage, and the solid-state light source (LED 3). and a capacitor (C1) to which the output pulsating voltage is applied. A lighting device (4) according to a first aspect includes a current adjusting circuit (first constant current circuit 41) that adjusts a load current flowing from a rectifying circuit (40) to at least one of a solid-state light source and a capacitor (C1). A lighting device (4) according to a first aspect comprises a control circuit (43) that controls a current regulation circuit to increase and decrease a load current. The control circuit (43) controls the current adjustment circuit so that a load current larger than the load current flowing to the solid-state light source flows through the capacitor (C1) when the AC voltage starts to be input to the rectifier circuit (40). .

The lighting device (4) according to the first aspect increases the load current to increase the rate of rise of the voltage (VC1) across the capacitor (C1), thereby suppressing fluctuations in the amount of light from the solid-state light source. ) to the start of lighting of the solid-state light source can be shortened.

A lighting device (4) according to the second aspect can be realized by a combination with the first aspect. The lighting device (4) according to the second aspect preferably includes a voltage detection circuit (44) that detects the voltage (VC1) across the capacitor (C1). The control circuit (43) adjusts the current so as to reduce the load current before the voltage (VC1) across the capacitor (C1) detected by the voltage detection circuit (44) reaches the lighting start voltage (Vst) of the solid-state light source. It is preferred to control the circuit.

The lighting device (4) according to the second aspect prevents the solid-state light source from flowing a load current larger than that in a steady state when the lighting of the solid-state light source is started, that is, preventing the solid-state light source from instantaneously emitting light with higher luminance than in a steady state. be able to.

A lighting device (4) according to the third aspect can be realized by a combination with the first or second aspect. In the lighting device (4) according to the third aspect, the control circuit (43) reduces the load current when the elapsed time from the start of inputting the alternating voltage to the rectifier circuit (40) reaches the stop time. It is preferable to control the current regulation circuit as follows.

In the lighting device (4) according to the third aspect, when the voltage (VC1) across the capacitor (C1) does not rise for some reason, the control circuit (43) forcibly reduces the load current, causing a problem. can be prevented.

A lighting device (4) according to the fourth aspect can be realized by a combination with any one of the first to third aspects. The lighting device (4) according to the fourth aspect includes a phase angle detection circuit (control circuit 43) that detects the phase angle of the phase-controlled AC voltage from the pulsating voltage when the AC voltage is phase-controlled. is preferred. Preferably, the control circuit (43) controls the current regulation circuit to increase and decrease the load current corresponding to the phase angle detected by the phase angle detection circuit. Preferably, the control circuit (43) further increases the load current regardless of the phase angle when the AC voltage starts to be input to the rectifier circuit (40). Preferably, the control circuit (43) reduces the load current corresponding to the phase angle when the voltage (VC1) across the capacitor (C1) reaches the lighting start voltage (Vst) of the solid-state light source.

In the lighting device (4) according to the fourth aspect, when the AC voltage (Vin) is phase-controlled when the AC power supply (8) is turned on, the lighting of the solid-state light source starts when the AC power supply (8) is turned on. It is possible to shorten the time required to

A lighting device (4) according to the fifth aspect can be realized by a combination with the fourth aspect. In the lighting device (4) according to the fifth aspect, the phase angle detection circuit delays a change in the phase-controlled pulsating current voltage (Va), and detects the phase angle from the change in the delayed pulsating current voltage (voltage Vm). is preferably detected. Preferably, the phase angle detection circuit further changes the delay time (time constant τ) for delaying the change in the pulsating current voltage (Va) in two or more stages. It is preferable that the phase detection circuit makes the delay time when the load current is increased shorter than the delay time when the load current is not increased.

In the lighting device (4) according to the fifth aspect, the delay time when the load current is increased is shorter than the delay time when the load current is not increased. It is possible to further shorten the period from turning on to lighting of the solid-state light source.

A lighting device (4) according to the sixth aspect can be realized by a combination with the fifth aspect. In the lighting device (4) according to the sixth aspect, it is preferable that the phase angle detection circuit changes the delay time in three or more stages.

The lighting device (4) according to the sixth aspect can further shorten the period from turning on the AC power supply (8) to lighting the solid-state light source.

A light-emitting device (2) according to a seventh aspect has the lighting device (4) according to any one of the first to sixth aspects, and a solid-state light source that is lit by the lighting device (4).

The light-emitting device (2) according to the seventh aspect can shorten the time required from turning on the AC power supply (8) to starting lighting of the solid-state light source while suppressing fluctuations in the light intensity of the solid-state light source.

A lighting fixture (1) according to an eighth aspect has a light emitting device (2) according to the seventh aspect and a fixture body (10) supporting the light emitting device (2).

The lighting fixture (1) according to the eighth aspect can shorten the time required from turning on the AC power supply (8) to starting lighting of the solid-state light source while suppressing fluctuations in the light intensity of the solid-state light source.

1 lighting equipment 2 light-emitting device 3 LED (solid-state light source)
4 Lighting device 8 AC power supply 10 Instrument body 40 Rectifier circuit 41 First constant current circuit (current adjustment circuit)
43 control circuit (phase angle detection circuit)
44 Voltage detection circuit C1 Capacitor VC1 Capacitor voltage Vst Lighting start voltage of solid-state light source Va Ripple current voltage Vm Voltage filtered by a low-pass filter (delayed pulsating current voltage)
τ Time constant (delay time)

Claims (7)

a rectifier circuit that rectifies an alternating voltage;
a capacitor electrically connected in parallel with the solid-state light source and to which the pulsating voltage output from the rectifier circuit is applied;
a voltage detection circuit that detects the voltage across the capacitor;
a current adjustment circuit that adjusts a load current flowing from the rectifier circuit to at least one of the solid-state light source and the capacitor;
a control circuit that controls the current adjustment circuit to increase and decrease the load current;
When the AC voltage starts to be input to the rectifier circuit, the control circuit causes the capacitor to pass a load current that is larger than the load current that flows to the solid-state light source in a steady state , and the voltage detection circuit controlling the current adjustment circuit to reduce the load current before the detected voltage across the capacitor reaches the lighting start voltage of the solid-state light source ;
lighting device. a rectifier circuit that rectifies an alternating voltage;
a capacitor electrically connected in parallel with the solid-state light source and to which the pulsating voltage output from the rectifier circuit is applied;
a current adjustment circuit that adjusts a load current flowing from the rectifier circuit to at least one of the solid-state light source and the capacitor;
a control circuit for controlling the current regulation circuit to increase and decrease the load current;
with
When the AC voltage starts to be input to the rectifier circuit, the control circuit causes the capacitor to pass a load current that is larger than the load current that flows to the solid-state light source in a steady state, and to the rectifier circuit. controlling the current adjustment circuit to reduce the load current when the elapsed time from the start of input of the alternating voltage reaches a stop time;
lighting device. a rectifier circuit that rectifies an alternating voltage;
a capacitor electrically connected in parallel with the solid-state light source and to which the pulsating voltage output from the rectifier circuit is applied;
a current adjustment circuit that adjusts a load current flowing from the rectifier circuit to at least one of the solid-state light source and the capacitor;
A phase angle for detecting a phase angle of the phase-controlled AC voltage from the pulsating current when the AC voltage is phase-controlled with a control circuit that controls the current adjustment circuit to increase and decrease the load current. detection circuit and
with
The control circuit controls the current adjustment circuit so as to increase and decrease the load current corresponding to the phase angle detected by the phase angle detection circuit;
Further, when the AC voltage starts to be input to the rectifier circuit, the control circuit increases the load current more than in a steady state regardless of the phase angle, and the voltage across the capacitor increases to the above reducing the load current corresponding to the phase angle when the lighting start voltage of the solid-state light source is reached;
lighting device. The phase angle detection circuit delays a change in the phase-controlled pulsating current voltage, detects the phase angle from the delayed change in the pulsating current voltage,
The phase angle detection circuit further changes the delay time for delaying the change in the pulsating current voltage in two or more stages, and increases the load current by changing the delay time when the load current is increased. being shorter than the delay time when not in use;
The lighting device according to claim 3 . The phase angle detection circuit changes the delay time in a plurality of stages of three or more stages,
The lighting device according to claim 4 . A lighting device according to any one of claims 1 to 5 ;
a solid-state light source that is lit by the lighting device;
Luminescent device. a light emitting device according to claim 6 ;
a fixture body that supports the light emitting device;
lighting equipment .

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