CN108882429B

CN108882429B - Lighting device and illumination system

Info

Publication number: CN108882429B
Application number: CN201710340364.8A
Authority: CN
Inventors: 李世春; 佐伯浩司
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2017-05-15
Filing date: 2017-05-15
Publication date: 2022-03-15
Anticipated expiration: 2037-05-15
Also published as: JP7012267B2; JP2018195569A; CN108882429A

Abstract

Provided is a lighting device which switches a lighting state by operating a wall switch and can suppress the occurrence of malfunction. The lighting device (20) is supplied with input power and supplies output power to the first light source (11) and the second light source (12), and the lighting device (20) is provided with: a switching circuit (70) that switches the ratio of output power supplied to the first light source (11) and the second light source (12), respectively; a first circuit (50) to which an input voltage corresponding to input power is input and which outputs a control voltage corresponding to the input voltage with a delay with respect to the input voltage; a control circuit (80) is inputted with a control voltage, controls the switch circuit (70) according to the value of the control voltage when the input power is reduced, and the time constant of the first circuit (50) is larger when the input voltage is reduced than when the input voltage is increased.

Description

Lighting device and illumination system

Technical Field

The present invention relates to a lighting device and a lighting system including the same.

Background

In a conventional lighting fixture that can be turned on and off by a wall switch, a technique is known in which the lighting state of the lighting fixture is changed by performing a predetermined operation on the wall switch. For example, patent document 1 discloses a technique of switching an LED to be lit by switching a wall switch from an on state (i.e., an on state) to an off state (i.e., an off state) and then switching the wall switch to the on state again for a predetermined time in a lighting fixture including a white LED (light Emitting diode) and a yellow LED. In this way, in the lighting fixture disclosed in patent document 1, one of the white LED and the yellow LED can be selectively turned on. In other words, in the lighting fixture disclosed in patent document 1, the light emission color of the lighting fixture can be switched, that is, the color can be adjusted, by operating the wall switch.

(Prior art document)

(patent document)

Japanese patent laid-open publication No. 2016-189344 (laid-open patent publication) of patent document 1

However, in the lighting apparatus described in patent document 1, when the voltage supplied to the lighting apparatus fluctuates due to a short power failure or the like, there is a problem that an erroneous operation of switching the emission color occurs, as in the case where the wall switch is operated as described above.

Disclosure of Invention

Therefore, an object of the present invention is to provide a lighting device that can switch a lighting state by operating a wall switch and can suppress the occurrence of malfunction, and a lighting system including the lighting device.

In order to achieve the above object, a lighting device according to an aspect of the present invention is a lighting device to which input power is supplied and which supplies output power to a first light source and a second light source, the lighting device including: a switching circuit that switches a ratio of the output power supplied to the first light source and the second light source, respectively; a first circuit to which an input voltage corresponding to the input power is input and which outputs a control voltage corresponding to the input voltage after delaying the control voltage from the input voltage; and a control circuit to which the control voltage is input, the control circuit controlling the switching circuit in accordance with a value of the control voltage when the input power decreases, and a time constant of the first circuit is larger when the input voltage decreases than when the input voltage increases.

In order to achieve the above object, an illumination system according to an aspect of the present invention includes: the lighting device, the first light source, and the second light source described above.

According to the present invention, it is possible to provide a lighting device that can switch a lighting state by operating a wall switch and suppress the occurrence of malfunction, and a lighting system including the lighting device.

Drawings

Fig. 1 is a circuit diagram showing an example of a circuit configuration of a lighting device and a lighting system according to an embodiment.

Fig. 2 is a circuit diagram showing a circuit configuration of a lighting device and an illumination system of a comparative example.

Fig. 3 is a graph schematically showing an example of the time waveforms of the CLK voltage and the VCC voltage in the control circuit of the lighting device according to the embodiment.

Fig. 4 is a circuit diagram showing an example of a circuit configuration of the lighting device and the illumination system according to the embodiment.

Fig. 5A is a circuit diagram showing an equivalent circuit of the first circuit in a case where the input voltage of the lighting device according to the embodiment rises.

Fig. 5B is a circuit diagram showing an equivalent circuit of the first circuit in the case where the input voltage of the lighting device according to the embodiment is reduced.

Fig. 6 is a circuit diagram showing an example of the circuit configuration of the lighting device and the illumination system according to the embodiment.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The embodiments to be described below are each a specific example of the present invention. Accordingly, the numerical values, shapes, materials, constituent elements, arrangement of constituent elements, connection modes, and the like shown in the following embodiments are merely examples, and the present invention is not limited thereto. Therefore, among the components in the following embodiments, components that are not described in the technical means illustrating the highest concept of the present invention will be described as arbitrary components. Each figure is a schematic diagram, and is not a strict illustration. In the drawings, the same components are denoted by the same reference numerals.

(embodiment mode 1)

A lighting device and an illumination system according to embodiment 1 will be described.

[1-1. construction of Lighting device and Lighting System ]

The configuration of the lighting device and the illumination system according to the present embodiment will be described with reference to the drawings.

Fig. 1 is a circuit diagram showing an example of the circuit configuration of the lighting device 20 and the illumination system 10 according to the present embodiment. Fig. 1 also shows a power supply 14 for supplying power to the lighting system 10, and a power switch 15 for turning on or off the lighting system 10. The power supply 14 is a system power supply such as a commercial power supply that outputs an ac power having a voltage of 100V.

The power switch 15 is a switch provided on an electric wire that supplies electric power from the power source 14 to the lighting system 10. When the power switch 15 is in the on state, power is supplied from the power source 14 to the lighting system 10, and when the power switch 15 is in the off state, power supply from the power source 14 to the lighting system 10 is cut off. As the power switch 15, a so-called wall switch or the like provided on a wall of a building such as a house can be used, for example.

The lighting system 10 is switched to a lighting state or a lighting-off state by the power switch 15. The lighting system 10 includes: a lighting device 20, a first light source 11, and a second light source 12.

The first light source 11 and the second light source 12 are light sources that generate light emitted from the illumination system 10. The first light source 11 and the second light source 12 include, for example, a plurality of LEDs connected in series, and emit light with direct current supplied from the conversion circuit 40. In the present embodiment, the second light source 12 has a different emission color from the first light source 11. For example, the first light source 11 emits light of a cold color (natural white) of about 5000K in color temperature, and the second light source 12 emits light of a warm color (eyeball color) of about 2700K in color temperature.

The lighting device 20 is a device to which input power is supplied and which supplies output power to the first light source 11 and the second light source 12. As shown in fig. 1, the lighting device 20 includes: a switching circuit 70, a first circuit 50, and a control circuit 80. In the present embodiment, the lighting device 20 further includes: a rectifier circuit 21, a smoothing capacitor 22,

resistance units

23, 24, 25, and 26, and a conversion circuit 40.

The switch circuit 70 is a circuit that switches the ratio of output power supplied to each of the first light source 11 and the second light source 12. In the present embodiment, the switching circuit 70 includes: a first switch 71, and a second switch 72. The first switch 71 is a switch connected in series with the first light source 11 and switches between an on state and an off state in response to a first switching signal from the control circuit 80. The second switch 72 is a switch connected in series with the second light source 12 and switches between an on state and an off state in accordance with a second switching signal from the control circuit 80. As the first switch 71 and the second switch 72, for example, a MOSFET (Metal-Oxide Semiconductor Field-Effect Transistor) can be used. In this case, the first switching signal and the second switching signal are input to the gate terminals of the first switch 71 and the second switch 72, respectively. By using such a switching circuit 70, the lighting or lighting-off of each of the first light source 11 and the second light source 12 can be switched. Therefore, the lighting state of the illumination system 10 can be switched to any one of the three lighting states, i.e., the first lighting state in which only the first light source 11 is lit, the second lighting state in which both the first light source 11 and the second light source 12 are lit, and the third lighting state in which only the second light source 12 is lit. The light emitted from the illumination system 10 is light of a warm color (color temperature of about 2700K) in the first lighting state, light of an intermediate color (color temperature of about 3500K) in the second lighting state, and light of a cold color (color temperature of about 5000K) in the third lighting state.

As described above, the switching circuit 70 according to the present embodiment can switch the ratio of the output power supplied to the first light source 11 and the second light source 12 with a simple configuration. In the illumination system 10 according to the present embodiment, the lighting state is switched, so that the emission color of the illumination system 10 can be switched. That is, in the lighting system 10, the color can be adjusted by operating the power switch 15.

The first circuit 50 is a circuit to which an input voltage corresponding to input power is input, and outputs a control voltage corresponding to the input voltage with a delay from the input voltage. In the first circuit 50, an input voltage is input from a node N1, which is an output terminal on the high potential side of the rectifier circuit 21, and a voltage generated from the input voltage is input from the conversion circuit 40. The first circuit 50 outputs a control voltage to the power supply terminal VCC of the control circuit 80. The detailed operation of the first circuit 50 will be described later. The first circuit 50 has: a control power supply circuit 510, a delay circuit 520, and a second rectifying element 54. The control power supply circuit 510 has a first capacitance unit 51. The delay circuit 520 includes: a second capacitor unit 52, and a first rectifier element 53.

The first capacitor unit 51 is a capacitor unit to which a voltage corresponding to the input voltage is applied. The second capacitance unit 52 is a capacitance unit to which a voltage generated from the input voltage is applied. Also, here, the voltage generated from the input voltage may be a voltage corresponding to the input voltage. As the first capacitor unit 51 and the second capacitor unit 52, for example, an electrolytic capacitor can be used. In the present embodiment, the second capacitor unit 52 has a larger capacity than the first capacitor unit 51. For example, the first capacitor unit 51 and the second capacitor unit 52 may have a capacity of about 10 μ F and a capacity of about 30 μ F, respectively.

The high-potential-side terminal of the first capacitor unit 51 is connected to one terminal of the resistor unit 25 at the node N3, and is also connected to the power supply terminal VCC of the control circuit 80. The high-potential-side terminal of the second capacitor unit 52 is connected to a node N4, which is a connection point between the first rectifier device 53 and the second rectifier device 54 at a node N4. The low-potential terminals of the first capacitor unit 51 and the second capacitor unit 52 are grounded.

The first rectifying element 53 is a rectifying element having one end and the other end connected to the first capacitor unit 51 and the second capacitor unit 52, respectively, and allows a current from the second capacitor unit 52 to flow to the first capacitor unit 51, but does not allow a current from the first capacitor unit 51 to flow to the second capacitor unit 52. As the first rectifying element 53, for example, a diode can be used. The cathode terminal and the anode terminal of the first rectifying element 53 are connected to the node N3 and the node N4, respectively.

The second rectifying element 54 is a rectifying element connected in series to the second capacitor unit 52, and allows a current from the converter circuit 40 to flow to the second capacitor unit 52, but does not allow a current from the second capacitor unit 52 to flow to the converter circuit 40. In this way, the charge stored in the second capacitor unit 52 can be prevented from flowing out to the conversion circuit 40. As the second rectifying element 54, for example, a diode can be used. The cathode terminal and the anode terminal of the second rectifying element 54 are connected to the node N4 and one end of the resistance unit 26, respectively.

The control circuit 80 is a circuit to which a control voltage is input from the first circuit 50 and controls the switch circuit 70 in accordance with the value of the control voltage when the input power decreases. The control circuit 80 is realized by a microcomputer (microcomputer), for example. A microcomputer is a single-chip semiconductor integrated circuit having a ROM and a RAM in which programs are stored, a processor (CPU) that executes the programs, a timer, an input/output circuit, and the like. The control circuit 80 includes: a clock terminal CLK, a ground terminal GND, a power supply terminal VCC, a driving terminal DRV, a first switching terminal SW1, and a second switching terminal SW 2.

The clock terminal CLK is a terminal to which a voltage corresponding to the voltage of the node N1 is input, and is used to detect a decrease in the input voltage to the lighting device 20 and measure the time of the decrease in the input voltage. The ground terminal GND is a terminal for grounding the control circuit 80. The power supply terminal VCC is a terminal to which a control voltage is input. The control voltage input to the power supply terminal VCC is used to switch the switching circuit 70. The drive terminal DRV is a terminal that outputs a signal for driving the switching element 41 of the conversion circuit 40. The first switching terminal SW1 and the second switching terminal SW2 are terminals that control the first switch 71 and the second switch 72, respectively, and output a first switching signal and a second switching signal, respectively. The rectifier circuit 21 is a circuit that rectifies input power from the power supply 14. The rectifier circuit 21 can be, for example, a diode bridge.

The smoothing capacitor 22 is an element for smoothing the voltage having the ripple output from the rectifier circuit 21. Two terminals of the smoothing capacitor 22 are connected to two output terminals of the rectifier circuit 21, respectively. As the smoothing capacitor 22, for example, an electrolytic capacitor can be used.

The

resistance units

23 and 24 are elements for dividing the voltage smoothed by the smoothing capacitor 22. The

resistance units

23 and 24 are connected in series, and a voltage at a connection point (node N2) between the resistance unit 23 and the resistance unit 24 is input to a clock terminal CLK of the control circuit 80. The resistance values of the

resistance units

23 and 24 are determined based on the output voltage of the power supply 14 and the voltage required for the clock terminal CLK of the control circuit 80. The resistance values of the

resistance units

23 and 24 are, for example, about 1000k Ω and 30k Ω, respectively, and when the lighting device 20 is supplied with a voltage of AC100V from the power supply 14, a voltage of about 4V is input to the clock terminal CLK.

The

resistance units

25 and 26 are protection resistors for reducing the current flowing to the first circuit 50. One and the other terminals of the resistance unit 25 are connected to the high-potential-side terminal (node N1) of the smoothing capacitor 22 and the first circuit 50, respectively. One and the other terminals of the resistance unit 26 are connected to the conversion circuit 40 and the first circuit 50, respectively. The resistance values of the

resistance units

25 and 26 are, for example, about 100k Ω to 1000k Ω.

The converter circuit 40 is a circuit that converts the dc power rectified by the rectifier circuit 21 and smoothed by the smoothing capacitor 22 into output power, and supplies the output power to the first light source 11 and the second light source 12. In the present embodiment, the converter circuit 40 is a flyback DC/DC converter. The conversion circuit 40 has: a switching element 41, a transformer 42, a rectifying element 43, and a capacitor unit 44.

The switching element 41 is an element for chopping, and repeatedly switches between an on state and an off state at a duty ratio corresponding to a required output power. The switching element 41 is switched to an on state or an off state in accordance with an output signal from the drive terminal DRV of the control circuit 80. As the switching element 41, for example, a MOSFET is used. The output signal from the driving terminal DRV is input to the gate terminal of the switching element 41.

The transformer 42 has a primary coil 42a, a secondary coil 42b, and an auxiliary coil 42 c. The transformer 42 is an inductor that transfers the energy of the current chopped by the switching element 41 from the primary coil 42a to the secondary coil 42b and the auxiliary coil 42 c. The primary coil 42a is connected in series with the switching element 41. The auxiliary coil 42c is an inductor for applying a voltage to the first circuit 50, and applies a voltage generated from an input voltage to the first circuit 50 via the resistance unit 26.

The rectifier device 43 rectifies the current flowing into the converter circuit 40. The rectifier device 43 is connected in series with the secondary coil 42b of the transformer 42. The rectified power is supplied to the first light source 11 and the second light source 12 as output power. The capacitor unit 44 is a unit for smoothing the output power of the converter circuit 40. In the present embodiment, an electrolytic capacitor can be used as the capacitor unit 44.

[1-2. work ]

The operation of the lighting device 20 and the illumination system 10 according to the present embodiment will be described. In order to explain the effects of the lighting device 20 according to the present embodiment, the following description will be made with reference to the drawings while comparing the lighting device and the illumination system of the comparative example.

Fig. 2 is a circuit diagram showing circuit configurations of a lighting device 920 and an illumination system 910 according to a comparative example. As shown in fig. 2, the lighting device 920 and the illumination system 910 of the comparative example are different from the lighting device 20 and the illumination system 10 according to the present embodiment in the first circuit 950, and are otherwise identical. The first circuit 950 of the comparative example does not include the second capacitor unit 52 and the first rectifier device 53, and the second rectifier device 54 is connected to the node N3. That is, the first circuit 950 of the comparative example does not include the delay circuit 520. The operation of the lighting device 20 according to the present embodiment will be described.

In the lighting device 20, the lighting state can be switched to any one of the first lighting state, the second lighting state, and the third lighting state described above by a user performing a predetermined operation on the power switch 15. This prescribed operation is hereinafter referred to as a state switching operation. Specifically, the state switching operation is an operation of switching from the off state to the on state within a predetermined time limit after the user switches the power switch 15 from the on state to the off state. Here, the predetermined time limit is, for example, about 1 second. For example, if the lighting device 20 is in the first lighting state, it can be switched to the second lighting state by the state switching operation. Similarly, when the lighting device 20 is in the second lighting state, it can be switched to the third lighting state by the state switching operation, and when the lighting device 20 is in the third lighting state, it can be switched to the first lighting state by the state switching operation.

In order to realize such an operation, the control circuit 80 monitors variations in a voltage (CLK voltage) and a control voltage (VCC voltage) corresponding to input voltages respectively input to the clock terminal CLK and the power supply terminal VCC. The control circuit 80 starts counting the clock when the CLK voltage input to the clock terminal CLK becomes equal to or less than the threshold Vth. In the present embodiment, the threshold Vth is 1V. Here, the case where the CLK voltage is equal to or lower than the threshold Vth corresponds to the case where the power switch 15 is turned off.

When detecting that the CLK voltage is equal to or lower than the threshold Vth for a predetermined time Δ t, the control circuit 80 detects the VCC voltage input to the power supply terminal VCC. In the present embodiment, the predetermined time Δ t is, for example, about 20 msec. When the detected VCC voltage is equal to or higher than the off voltage Voff and equal to or lower than the on voltage Von, the control circuit 80 determines that the power switch 15 is switched to the on state again, and switches the lighting state. That is, the first switch 71 and the second switch 72 output a first switching signal and a second switching signal for switching the lighting state, respectively. In the present embodiment, a region in which the VCC voltage is equal to or higher than the off voltage Voff and equal to or lower than the on voltage Von is referred to as a luminescent color switching region. The off voltage Voff and the on voltage Von are, for example, about 10V and about 15V, respectively.

When it is detected that the state in which the CLK voltage is equal to or lower than the threshold Vth continues for the predetermined time Δ t, the control circuit 80 determines that the state switching operation is not performed and the lighting state is not changed when the detected VCC voltage is equal to or higher than the reset voltage Vrst and is lower than the off voltage Voff. This corresponds to, for example, a case where the time until the power switch 15 is switched to the on state again after being switched from the on state to the off state is longer than a predetermined time. In the present embodiment, a region in which the VCC voltage is equal to or higher than the reset voltage Vrst and is lower than the off voltage Voff is referred to as a light emission color maintaining region. The reset voltage Vrst is, for example, about 2V.

When the VCC voltage detected is less than the reset voltage Vrst when the control circuit 80 detects that the state where the CLK voltage is equal to or less than the threshold Vth continues for the predetermined time Δ t, the lighting state is reset. That is, the control circuit 80 returns the lighting state of the lighting device 20 to the initial state. This corresponds to a case where the power switch 15 is maintained in the off state for a sufficiently long time. The initial state may be determined as any one of a first lighting state, a second lighting state, and a third lighting state. In the present embodiment, a region in which the VCC voltage is less than the reset voltage Vrst is referred to as a reset region. When the control circuit 80 determines that the CLK voltage is greater than the threshold Vth, the timing is stopped.

Also in the lighting device 920 of the comparative example, the control circuit 80 performs the same operation as the control circuit 80 according to the present embodiment. However, the lighting device 920 of the comparative example differs from the lighting device 20 according to the present embodiment in the configuration of the first circuit 950, and therefore differs from the operation of the lighting device 20 according to the present embodiment.

The operation of the lighting device 20 according to the present embodiment and the lighting device 920 according to the comparative example will be described below based on an operation example. Fig. 3 is a graph schematically showing an example of the time waveforms of the CLK voltage and the VCC voltage in the control circuit 80 of the lighting device 20 according to the present embodiment. Examples of the time waveforms of the CLK voltage and the VCC voltage are shown by solid lines in the graph (a) and the graph (b) of fig. 3, respectively. In fig. 3, an example of time waveforms of the CLK voltage and the VCC voltage of the lighting device 920 of the comparative example is shown by a broken line.

In the operation example shown in fig. 3, first, at time T0 in fig. 3, the power switch 15 is switched from the off state to the on state. Accordingly, the CLK voltage and the VCC voltage rise as the input voltage at the node N1 rises. Immediately after time T0, in any of the lighting devices of the present embodiment and the comparative example, since the first capacitor unit 51 is charged, the CLK voltage and the VCC voltage gradually rise with a time constant determined by the capacity of the first capacitor unit 51. In the lighting device 20 according to the present embodiment, the second capacitor unit 52 of the first circuit 50 is also charged. Here, the first circuit 50 includes a first rectifying element 53, and one end and the other end of the first rectifying element 53 are connected to the first capacitor unit 51 and the second capacitor unit 52, respectively, so that a current from the second capacitor unit 52 to the first capacitor unit 51 flows, but a current from the first capacitor unit 51 to the second capacitor unit 52 does not flow. Therefore, when the input voltage rises, the first rectifying element 53 is connected to the node N3, and the node N3 is higher than the voltage of the node N4, so that the node N3 and the node N4 can be substantially regarded as being disconnected. Therefore, the control voltage (i.e., the VCC voltage) output from the first circuit 50 according to the present embodiment is changed similarly to the case where the second capacitor unit 52 is not connected to the node N1. That is, when the input voltage increases, the time constant of the first circuit 50 according to the present embodiment is substantially determined only by the first capacitor unit 51, and therefore, is substantially the same as the time constant of the first circuit 950 of the comparative example. In the lighting device 20 according to the present embodiment, the second capacitor unit 52 is charged by the converter circuit 40.

After these CLK voltages and the control voltage are stabilized, the state switching operation is performed from time T1 to time T4. Specifically, at time T1, power switch 15 is switched from the on state to the off state. Accordingly, as the input voltage decreases, the CLK voltage and the VCC voltage also decrease. However, in the present embodiment, when the input voltage is reduced, that is, when the voltages of the node N1 and the node N3 are reduced, the node N4 is at a higher potential than the node N3. In this case, since a current flows from the second capacitor unit 52 to the node N3 through the first rectifier device 53, the time constant of the first circuit 50 is different from that of the first circuit 950 of the comparative example. That is, the first circuit according to the present embodiment is equivalent to a circuit in which the second capacitor is directly connected to the node N3 when the input voltage is reduced. Therefore, the time constant of the first circuit 50 is determined by the first capacitor unit 51 and the second capacitor unit 52 connected in parallel with the first capacitor unit 51. Therefore, in the case where the input voltage is reduced, the time constant of the first circuit 50 is larger than that of the first circuit 950 of the comparative example. As described above, in the present embodiment, it is possible to realize, with a simple configuration, a lighting device in which the time constant of the first circuit 50 is larger when the input voltage is decreased than when the input voltage is increased.

Accordingly, as shown in fig. 3, from time T1 to time T4, the CLK voltage and the VCC voltage according to the present embodiment are gradually decreased as compared with the CLK voltage and the VCC voltage of the comparative example, respectively.

Next, the operation of the control circuit 80 in the state switching operation during the period from the time T1 to the time T4 will be described. After the power switch 15 is switched to the off state at time T1, the CLK voltage starts to fall from the voltage Vmax as shown in fig. 3, and becomes equal to or lower than the threshold Vth at time T3. Accordingly, when the control circuit 80 detects that the CLK voltage is equal to or lower than the threshold Vth, the timer is started. After that, at time T4, the power switch 15 is switched from the off state to the on state. In turn, the CLK voltage and the VCC voltage transition from falling to rising. Here, when time Δ T elapses from time T3, the CLK voltage becomes equal to or lower than threshold Vth, and the VCC voltage becomes equal to or lower than on voltage Von and equal to or higher than off voltage Voff (emission color switching region in fig. 3). For this reason, the control circuit 80 determines that the state switching operation is performed, and switches the lighting state. That is, the first switch 71 and the second switch 72 output the first switching signal and the second switching signal for switching the lighting state from the first switching terminal SW1 and the second switching terminal SW2, respectively.

Similarly, in the lighting device 920 of the comparative example, the CLK voltage gradually decreases from the time T1 to the time T4, and becomes equal to or less than the threshold Vth at the time T2. Therefore, from time T2, control circuit 80 starts timing. After that, at the time point when the time Δ T has elapsed from the time point T2, since the CLK voltage is equal to or less than the threshold Vth, the VCC voltage is equal to or less than the on voltage Von, and the off voltage Voff is equal to or more than the off voltage, the control circuit 80 of the comparative example determines that the state switching operation has been performed, and switches the lighting state.

In the lighting devices of the present embodiment and the comparative example, when the power switch 15 is switched to the on state much later than the time T4, the VCC voltage detected after the lapse of the predetermined time Δ T from the time when the CLK voltage becomes equal to or lower than the threshold Vth can be equal to or lower than the off voltage Voff. For example, when the VCC voltage is equal to or higher than the reset voltage and is less than the off voltage (the emission color maintaining region in fig. 3), the control circuit 80 does not switch the lighting state. When the VCC voltage is less than the reset voltage (reset region in fig. 3), the control circuit 80 resets the lighting state.

Next, an operation in the case where an instantaneous power failure occurs in the power supply 14 during the period from time T5 to time T7 will be described. From time T5 to time T7, even if the power supply 14 has a momentary power failure, the input power to the lighting device 20 according to the present embodiment and the lighting device 920 according to the comparative example is reduced, and the input voltage at the node N1 is reduced accordingly, as in the case where the power supply switch 15 is turned off. As shown in fig. 3, in the lighting device 920 of the comparative example, since the CLK voltage and the VCC voltage drop rapidly compared to the present embodiment, the CLK voltage becomes equal to or less than the threshold Vth at time T6. Here, in an instantaneous power failure, since the power failure state generally lasts for about several tens of msec, the CLK voltage can be maintained at the threshold Vth or less for a predetermined time Δ t (20msec) or more. After a predetermined time Δ T has elapsed from time T6, the VCC voltage becomes equal to or higher than the off voltage Voff and equal to or lower than the on voltage Von as shown in fig. 3. Therefore, in the lighting device 920 of the comparative example, when an instantaneous power failure occurs, it is determined that the state switching operation is performed, and an erroneous operation occurs.

However, even after time T5 at which the instantaneous power failure occurs, the CLK voltage and the VCC voltage decrease as the input voltage decreases in the lighting device 20 according to the present embodiment. However, as described above, since the first circuit 50 of the lighting device 20 according to the present embodiment includes the second capacitor unit 52 and the first rectifying element 53, the time constant of the first circuit 50 when the input voltage is reduced is larger than the time constant of the first circuit 950 according to the comparative example. As described above, in the present embodiment, the decrease in the CLK voltage and the VCC voltage is relatively gentle compared to the decrease in the CLK voltage and the VCC voltage in the comparative example. Therefore, in the present embodiment, the decrease in the CLK voltage is later than in the comparative example, and becomes equal to or less than the threshold Vth at time T7. In the present embodiment, when the input voltage increases, the time constant of the first circuit 50 is the same as that of the comparative example, and therefore, the CLK voltage can increase relatively rapidly as in the comparative example. Accordingly, the CLK voltage after a predetermined time Δ T has elapsed from time T7 is higher than the threshold Vth, and the timing in the control circuit 80 is stopped. Therefore, the control circuit 80 determines that the state switching operation is not performed, and does not switch the lighting state.

As described above, in the present embodiment, by making the value of the time constant of the first circuit 50 larger in the case of a decrease in the input voltage than in the case of an increase in the input voltage, it is possible to delay the fluctuation of the voltage input to the control circuit 80 in the case of an instantaneous decrease in the input power. Accordingly, in the lighting device 20 according to the present embodiment, it is possible to suppress the occurrence of malfunction due to the instability of the input power.

In addition, for example, in the lighting device 920 of the comparative example, the occurrence of the above-described malfunction can be suppressed only by using the capacitor unit having a large capacity for the first capacitor unit 51. However, in the configuration using the first capacitor unit 51 having such a large capacity, when the power switch 15 is switched from the off state to the on state, that is, when the input voltage increases, the rise of the VCC voltage becomes gentle. Therefore, in the lighting device 920 of the comparative example, it takes time to start the control circuit 80 at the time of lighting. However, in the lighting device 20 according to the present embodiment, since the time constant of the first circuit 50 when the input voltage increases is smaller than the time constant of the first circuit 50 when the input voltage decreases, the control circuit 80 can be started up quickly when lighting. That is, the lighting device 20 can be quickly lighted.

In the present embodiment, since the first circuit 50 includes the second rectifier device 54 connected in series with the second capacitor unit 52, the flow of the charge charged in the second capacitor unit 52 to the converter circuit 40 can be suppressed. Therefore, when the input voltage decreases, the electric charge charged in the second capacitor unit 52 substantially flows out only to the first rectifier device 53 side, and therefore the effect of increasing the time constant of the second capacitor unit 52 can be further improved.

In the present embodiment, the second capacitor unit 52 has a larger capacity than the first capacitor unit 51. In this way, by making the capacity of the first capacitor unit 51 relatively small, the start-up of the control circuit 80 when the lighting device 20 is lit can be further accelerated. That is, the lighting device 20 can be lighted more quickly. Further, by making the capacity of the second capacitor unit 52 relatively large, when the input voltage decreases, the decrease in the control voltage input to the control circuit 80 can be further delayed, and therefore, the occurrence of malfunction due to instability of the input power can be further suppressed.

[1-3. Effect, etc. ]

As described above, the lighting device 20 according to the present embodiment is supplied with the input power and the output power to the first light source 11 and the second light source 12, and the lighting device 20 includes: a switching circuit 70 that switches the ratio of output power supplied to the first light source 11 and the second light source 12, respectively; a first circuit 50 to which an input voltage corresponding to input power is input and which outputs a control voltage corresponding to the input voltage with a delay from the input voltage; and a control circuit 80 to which a control voltage is input, the control circuit controlling the switching circuit 70 and the time constant of the first circuit according to the value of the control voltage when the input power decreases, and the time constant being larger when the input voltage decreases than when the input voltage increases.

In this way, the lighting device 20 can switch the lighting states of the first light source 11 and the second light source 12 by varying the input power. Therefore, in the lighting device 20, when the input power is supplied from the power supply 14 through the power switch 15, the lighting state can be switched by operating the power switch 15. In the lighting apparatus 20, the time constant of the first circuit 50 when the input voltage is reduced is increased, and thus, when the input power is unstable, the variation of the control voltage input to the control circuit 80 can be delayed, and thus, the occurrence of malfunction due to instability can be suppressed. In the lighting device 20, since the time constant of the first circuit 50 when the input voltage is increased is reduced, rapid lighting can be realized. As described above, in the lighting device 20, the first circuit 50 includes: a first capacitor unit 51 to which a voltage corresponding to the input voltage is applied; a second capacitance unit 52 to which a voltage generated from the input voltage is applied; and

the first rectifying element 53 has one end and the other end connected to the first capacitor unit 51 and the second capacitor unit 52, respectively, and causes a current to flow from the second capacitor unit 52 to the first capacitor unit 51, while preventing a current from flowing from the first capacitor unit 51 to the second capacitor unit 52.

With the configuration of the first circuit 50, when the input voltage increases, the time constant of the first circuit 50 is substantially determined only by the first capacitor unit 51, and when the input voltage decreases, the time constant of the first circuit 50 is determined by the first capacitor unit 51 and the second capacitor unit 52 connected in parallel to the first capacitor unit 51. Therefore, with a simple configuration, it is possible to realize a lighting device having a first circuit 50 with a time constant that is larger when the input voltage is decreased than when the input voltage is increased. As described above, in the lighting device 20, the second capacitance unit 52 has a larger capacity than the first capacitance unit 51.

In this way, by making the capacity of the first capacitor unit 51 relatively small, the start-up of the control circuit 80 at the time of lighting of the lighting device 20 can be further accelerated. That is, the lighting device 20 can be lighted more quickly. Further, by making the capacity of the second capacitor unit 52 relatively large, when the input voltage decreases, the decrease in the control voltage input to the control circuit 80 can be further delayed, and the occurrence of malfunction due to instability of the input power can be further suppressed. As described above, in the lighting apparatus 20, the first circuit 50 may further include the second rectifying element 54 connected in series with the second capacitor unit 52.

Accordingly, the outflow of the electric charge charged in the second capacitor unit 52 to the conversion circuit 40 can be suppressed. Therefore, when the input voltage decreases, the electric charge charged in the second capacitor unit 52 substantially flows out only to the first rectifier device 53 side, and therefore, the effect of increasing the time constant of the second capacitor unit 52 can be further improved. As described above, in the lighting device 20, the switching circuit 70 includes: a first switch 71 connected in series to the first light source 11 and switching an on state or an off state in response to a first switching signal from the control circuit 80; and a second switch 72 connected in series with the second light source 12 and switching between an on state and an off state in response to a second switching signal from the control circuit 80. Accordingly, the ratio of the output power supplied to the first light source 11 and the second light source 12 can be switched with a simple configuration. The lighting system 10 according to the present embodiment includes a lighting device 20, a first light source 11, and a second light source 12. Accordingly, the same effects as those of the lighting device 20 described above can be achieved. In the lighting system according to the present embodiment, the second light source 12 and the first light source 11 emit light of different colors.

Accordingly, by switching the lighting state, the light color of the light emitted from the illumination system 10 can be switched. That is, in the lighting system 10, the color can be adjusted by operating the power switch 15.

(embodiment mode 2)

A lighting device and an illumination system according to embodiment 2 will be described. The lighting device and the illumination system according to the present embodiment have a configuration that suppresses variation in operation. Hereinafter, the present embodiment will be described mainly focusing on differences from embodiment 1. First, the configuration of the lighting device and the illumination system according to the present embodiment will be described with reference to the drawings. Fig. 4 is a circuit diagram showing an example of the circuit configuration of the lighting device 120 and the illumination system 110 according to the present embodiment.

As shown in fig. 4, the lighting device 120 and the illumination system 110 according to the present embodiment are different from the lighting device 20 and the illumination system 10 according to embodiment 1 in the configuration of the first circuit 150. The configuration of the first circuit 150 according to the present embodiment will be described below.

As shown in fig. 4, the first circuit 150 is a circuit to which an input voltage corresponding to input power is input, and outputs a control voltage corresponding to the input voltage with a delay from the input voltage, as in the first circuit 50 according to embodiment 1. The first circuit 150 has: a first capacitor unit 51, a second capacitor unit 52, a first rectifier element 53, and a second rectifier element 54. In the present embodiment, the first circuit 150 further includes: a first resistance unit 55 connected in parallel with the first capacitance unit 51; and a second resistance unit 56 connected in parallel with the second capacitance unit 52. In other words, in this embodiment, the first circuit 150 includes the control power supply circuit 1510 and the delay circuit 1520, the control power supply circuit 1510 includes the first capacitor unit 51 and the second resistor unit 55, and the delay circuit 1520 includes the second capacitor unit 52 and the second resistor unit 56. By providing the first resistance unit 55 and the second resistance unit 56 in this way, when the power switch 15 is switched from the on state to the off state, the electric charges charged in the first capacitance unit 51 and the second capacitance unit 52 can be stably discharged to the ground via the first resistance unit 55 and the second resistance unit 56, respectively. In this way, since the variation in the time waveform of the VCC voltage when the power switch 15 is turned off can be reduced, the variation in the time required until the VCC voltage becomes less than the reset voltage Vrst from the time when the power switch 15 is switched from the on state to the off state is reduced. Here, parameters of each component of the first circuit 150 will be described using an equivalent circuit.

Fig. 5A is a circuit diagram showing an equivalent circuit 150A of the first circuit 150 in a case where the input voltage of the lighting device 120 according to the present embodiment increases. Fig. 5B is a circuit diagram showing an equivalent circuit 150B of the first circuit 150 in the case where the input voltage of the lighting device 120 according to the present embodiment is reduced.

When the input voltage of the lighting device 120 increases, the first rectifying element 53 is connected to the node N3, and the node N3 is higher than the voltage of the node N4, so that it can be considered that the node N3 and the node N4 are substantially disconnected from each other. Therefore, as shown in fig. 5A, the equivalent circuit 150A of the first circuit 150 is represented by a circuit in which the first capacitance unit 51 is connected in parallel with the first resistance unit 55. Therefore, the time constant τ 1 of the first circuit 150 when the input voltage increases can be expressed as follows, assuming that the capacitance of the first capacitor unit 51 is C1 and the resistance value of the first resistor unit 55 is R1.

τ1＝C1×R1

When the input voltage of the lighting device 120 decreases, the first rectifying element 53 is connected to the node N3, and the node N3 is lower than the node N4 in voltage, so that it can be considered that the node N3 and the node N4 are substantially conductive. For this reason, as shown in fig. 5B, the equivalent circuit 150B of the first circuit 150 is represented by a circuit in which the first capacitance unit 51, the first resistance unit 55, the second capacitance unit 52, and the second resistance unit 56 are connected in parallel. Therefore, the time constant τ 2 of the first circuit 150 when the input voltage is reduced can be expressed as follows, assuming that the capacitance of the second capacitor unit 52 is C2 and the resistance value of the second resistor unit 56 is R2.

τ2＝(C1+C2)×R1×R2/(R1+R2)

Here, in this embodiment as well, as in embodiment 1, the time constant of the first circuit 150 is larger when the input voltage is decreased than when the input voltage is increased. That is, the capacitance of each capacitor unit and the resistance value of each resistor unit are set so that τ 1< τ 2 can be satisfied. For example, the capacitances C1 and C2 of the first capacitor unit 51 and the second capacitor unit 52 are about 10 μ F and about 30 μ F, respectively, and the resistances R1 and R2 of the first resistor unit 55 and the second resistor unit 56 are about 200k Ω and about 100k Ω, respectively. By using the first resistance unit 55 and the second resistance unit 56 having such resistance values, the same effects as those of the lighting device 20 and the lighting system 10 according to embodiment 1 can be achieved, and the lighting device 120 and the lighting system 110 in which the variation in operation is suppressed can be achieved.

(embodiment mode 3)

A lighting device and an illumination system according to embodiment 3 will be described. The lighting device and the lighting system according to the present embodiment have a configuration in which the reset operation of the control circuit can be reliably executed, that is, the control voltage can be reliably reduced. Hereinafter, the present embodiment will be described mainly focusing on differences from embodiment 2. First, the configuration of the lighting device and the illumination system according to the present embodiment will be described with reference to the drawings. Fig. 6 is a circuit diagram showing an example of the circuit configuration of the lighting device 220 and the illumination system 210 according to the present embodiment.

As shown in fig. 6, the lighting device 220 and the lighting system 210 according to the present embodiment are different from the lighting device 120 and the lighting system 110 according to embodiment 2 in the configuration of the first circuit 250. The configuration of the first circuit 250 according to the present embodiment will be described below.

The first circuit 250 according to the present embodiment has the same components as the first circuit 150 according to embodiment 2, and further includes a zener diode 57 connected in series to the first capacitor unit 51. The zener diode 57 is an element that surely lowers the control voltage output from the first circuit 250 to less than the reset voltage Vrst when the power switch 15 is switched from the on state to the off state.

As shown in fig. 6, when the power switch 15 connected between the power supply 14 and the lighting device 220 is a one-off switch that disconnects one of two wires connecting the power supply 14 and the lighting device 220, the zener diode 57 according to the present embodiment has a more significant effect. That is, in the case where the power switch 15 is a one-off type switch, even when the power switch 15 is in an off state, one of the electric wires is connected to the power source 14 and the lighting device 220, and thus a leakage current flows from the power source 14 to the lighting device 220. Accordingly, even when the power switch 15 is switched from the on state to the off state, the control voltage output from the first circuit 250 may not be lowered to be lower than the reset voltage Vrst.

In the present embodiment, a zener diode 57 is connected to the node N3 of the first circuit 250. Here, by setting the breakdown voltage of the zener diode 57 to a voltage sufficiently higher than the reset voltage Vrst than the input voltage, the voltage applied to the node N3 of the first circuit 250 can be reliably lowered to be lower than the reset voltage Vrst when the power switch 15 is turned off. Therefore, in the lighting device 220 according to the present embodiment, the reset operation can be reliably performed in the control circuit 80.

(modification example etc.)

The present invention has been described above based on the embodiments, but the present invention is not limited to the embodiments.

For example, in the above embodiments, an ac power supply is used as the power supply 14, but a dc power supply may be used as the power supply 14. In this case, the lighting device 20 may not include the rectifier circuit 21 and the smoothing capacitor 22. The number of light sources included in the illumination system is not limited to two, and may be three or more.

In the above embodiments, the LED is used as the light source, but the type of the light source is not limited to the LED. As the light source, for example, other optical elements such as an organic EL element may be used.

In the above embodiments, the first light source 11 and the second light source 12 have different emission colors from each other, but may have the same emission color. In this case, for example, the first light source 11 and the second light source 12 may have different light distribution characteristics from each other. The first light source 11 and the second light source may be disposed at different positions.

The lighting system according to each of the above embodiments may be housed in one housing, or each light source may be housed in a different housing. The lighting device and the light sources may be disposed in other housings, and the housings may be connected to each other by wires.

In the above embodiments, the switch circuit 70 includes the first switch 71 and the second switch 72 that can turn off the currents flowing into the first light source 11 and the second light source 12, respectively, but the configuration of the switch circuit 70 is not limited to this. For example, the switching circuit 70 may include a variable resistance element connected in series to each light source. In this case, the ratio of the output power supplied to each light source by the lighting device can be switched by changing the resistance value of the variable resistive element connected in series to each light source. The first capacitor unit 51 and the second capacitor unit 52 may be capacitor units using a stray capacitance, instead of electrolytic capacitors or the like. Each resistance unit may be a resistance element, or may be a resistance unit in a wire or the like.

In addition, the present invention includes a configuration in which various modifications that can be conceived by a person skilled in the art are implemented in each embodiment, or a configuration in which constituent elements and functions in each embodiment are combined, without departing from the gist of the present invention.

Description of the symbols

10. 110, 210 lighting system

11 first light source

12 second light source

14 power supply

20. 120, 220 lighting device

50. 150, 250 first circuit

51 first capacitor unit

52 second capacitor unit

53 first rectifying element

54 second rectifying element

55 first resistance unit

56 second resistance unit

70 switching circuit

71 first switch

72 second switch

80 control circuit

Claims

1. A lighting device to which input power is supplied and which supplies output power to a first light source and a second light source,

the lighting device includes:

a switching circuit that switches a ratio of the output power supplied to the first light source and the second light source, respectively;

a first circuit to which an input voltage corresponding to the input power is input and which outputs a control voltage corresponding to the input voltage after delaying the control voltage from the input voltage; and

a control circuit to which the control voltage is input, the control circuit controlling the switching circuit in accordance with a value of the control voltage when the input power decreases,

wherein the first circuit includes:

a first capacitance unit to which a voltage corresponding to the input voltage is applied;

a second capacitance unit to which a voltage generated from the input voltage is applied; and

a first rectifying element having one end and the other end connected to the first capacitor unit and the second capacitor unit, respectively, for causing a current from the second capacitor unit to the first capacitor unit and not causing a current from the first capacitor unit to the second capacitor unit to flow,

the time constant of the first circuit is larger in the case where the input voltage decreases than in the case where the input voltage increases, so that the change of the control voltage in the case where the input voltage decreases is gentler than the change in the case where the input voltage increases.

2. The lighting device as set forth in claim 1,

the second capacitance unit has a larger capacity than the first capacitance unit.

3. The lighting device according to claim 1 or 2,

the first circuit further includes:

a first resistance unit connected in parallel with the first capacitance unit; and

and a second resistance unit connected in parallel with the second capacitance unit.

4. The lighting device according to claim 1 or 2,

the first circuit further includes a zener diode connected in series with the first capacitor unit.

5. The lighting device according to claim 1 or 2,

the first circuit further includes a second rectifying element connected in series to the second capacitor unit.

6. The lighting device according to claim 1 or 2,

the switching circuit includes:

a first switch connected in series with the first light source and switching an on state or an off state according to a first switching signal from the control circuit; and

and a second switch connected in series with the second light source and switching an on state or an off state according to a second switching signal from the control circuit.

7. An illumination system is provided with:

the lighting device of any one of claims 1 to 6; and

the first light source and the second light source.

8. The lighting system as set forth in claim 7,

the second light source has a different luminescent color from the first light source.