CN110650565A

CN110650565A - LED lighting device and lighting fixture

Info

Publication number: CN110650565A
Application number: CN201910537767.0A
Authority: CN
Inventors: 竹口直辉; 井户滋; 城户大志
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2018-06-27
Filing date: 2019-06-20
Publication date: 2020-01-03
Anticipated expiration: 2039-06-20
Also published as: JP2020004553A; CN110650565B; JP7042430B2

Abstract

The invention provides an LED lighting device and a lighting fixture, which are difficult to generate color flicker under the condition that unlit colors exist in the sequential lighting process. An LED lighting device (30) lights N LED loads (21-24) having N (N is an integer of more than 2) luminous colors, and when a toning instruction is received, which instructs to light M (M is an integer smaller than N) LED loads and not to light (N-M) LED loads, either (i) a first control in which a selector circuit (32) selects at least one LED load of the M LED loads in a plurality of time slots of the N time slots, or (ii) a second control in which a periodic M time slots are set, and the selector circuit (32) selects the M LED loads in a circulating manner in the M time slots.

Description

LED lighting device and lighting fixture

Technical Field

The present invention relates to an LED lighting device and a lighting fixture for lighting a plurality of LEDs (Light Emitting diodes) having different emission colors.

Background

Patent document 1 discloses an illumination device capable of dimming and color-adjusting by lighting a plurality of LEDs having different emission colors in a sequentially switched manner and adjusting the intensity and mixing ratio of each emission color.

Patent document 1: japanese patent laid-open publication No. 2004-311635

Disclosure of Invention

Problems to be solved by the invention

However, according to the above-described prior art, there are the following problems: in the case where there is an unlit color in the sequential lighting process, for example, when LED light sources of four colors of RGBW can be lit but two of the colors are lit but the other two colors are not lit, the light-off section becomes long, and color flicker is likely to occur. Here, the sequential lighting means lighting in which a plurality of LED light sources having different emission colors are sequentially switched over a predetermined fixed time period and the process is repeated. In addition, color flicker refers to: when an object which moves rapidly like a blade of an electric fan is present under illumination light, each light emission color of the LED light source is represented on the object and is perceived by a human. When the color flicker is increased, the user may feel uncomfortable and not fast.

Therefore, an object of the present invention is to provide an LED lighting device and a lighting fixture, in which color flicker is less likely to occur when unlit colors are present during sequential lighting.

Means for solving the problems

In order to achieve the above object, one aspect of the LED lighting device according to the present invention is an LED lighting device for lighting N LED loads having N (N is an integer of 2 or more) emission colors, the LED lighting device including: a power supply circuit that supplies power to the N LED loads; a selector circuit that supplies power from the power supply circuit to the selected LED load by selecting one LED load from the N LED loads; and a control circuit that performs the following sequence control: setting a periodic N time slots in which the selector circuit is caused to select the N LED loads in a round robin manner, wherein the control circuit performs either (i) first control or (ii) second control when receiving a toning instruction instructing to light M (M is an integer smaller than N) LED loads and not to light (N-M) LED loads, in the first control, the selector circuit (32) is caused to select the M LED loads in a round-robin manner in the N time slots, and cause the selector circuit to select at least one of the M LED loads in a plurality of time slots, in the second control, a periodic M number of time slots are set instead of the N number of time slots, and the selector circuit selects the M number of LED loads in a round-robin manner among the M number of time slots.

The lighting device according to the present invention includes the LED lighting device and the plurality of LED loads.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the LED lighting device and the lighting fixture of the present invention, the following effects are provided: color flicker is less likely to occur when unlit colors are present during sequential lighting.

Drawings

Fig. 1 is a block diagram showing a configuration example of a lighting fixture including an LED lighting device according to embodiment 1.

Fig. 2 is a diagram showing an example of current waveforms in sequential control for causing the lighting fixture according to embodiment 1 to emit light in all colors.

Fig. 3A is a diagram showing an example of a current waveform in the first control for causing the lighting fixture according to embodiment 1 to emit light in two colors.

Fig. 3B is a diagram showing an example of a current waveform in the second control for causing the lighting fixture according to embodiment 1 to emit light in two colors.

Fig. 3C is a diagram showing another example of the current waveform in the second control for causing the lighting fixture according to embodiment 1 to emit light in two colors.

Fig. 4A is a diagram showing an example of a current waveform in the first control for causing the lighting fixture according to embodiment 1 to emit light in three colors.

Fig. 4B is a diagram showing an example of a current waveform in the second control for causing the lighting fixture according to embodiment 1 to emit light in three colors.

Fig. 5 is a diagram showing an example of a circuit configuration of a lighting fixture including the LED lighting device according to embodiment 1.

Fig. 6 is a diagram showing current waveforms and voltage waveforms of respective sections in the sequential control of emitting light of all colors in the lighting fixture according to embodiment 1.

Fig. 7A is a diagram showing current waveforms and voltage waveforms of respective portions in the first control for causing the lighting fixture according to embodiment 1 to emit light in two colors.

Fig. 7B is a diagram showing current waveforms and voltage waveforms of respective portions in the second control for causing the lighting fixture according to embodiment 1 to emit light in two colors.

Fig. 8A is a diagram showing an example of a waveform of a current in sequence control including unlit colors according to embodiment 2.

Fig. 8B is a diagram showing an example of a waveform of a current in the first control corresponding to fig. 8A.

Fig. 8C is a diagram showing an example of a waveform of a current in the second control corresponding to fig. 8B.

Fig. 9 is a diagram showing an example of the waveform of the current in the sequence control, the transition period, and the first control according to embodiment 3.

Fig. 10 is a diagram showing an example of the waveform of the current in the sequence control, the transition period, and the second control according to embodiment 4.

Fig. 11 is a diagram showing an example of the waveform of the current in the sequence control, the transition period, and the second control according to embodiment 5.

Fig. 12A is a diagram showing an example of the appearance of a lighting fixture including the LED lighting device according to each embodiment.

Fig. 12B is a diagram showing another example of the appearance of the lighting fixture including the LED lighting device according to each embodiment.

Fig. 12C is a diagram showing another example of the external appearance of the lighting fixture including the LED lighting device according to each embodiment.

Fig. 13 is a diagram showing a configuration of a lighting fixture as a comparative example.

Fig. 14A is a diagram showing current waveforms in an illumination operation in which the illumination fixture as a comparative example is caused to emit light in four colors.

Fig. 14B is a diagram showing a current waveform in an illumination operation in which the illumination fixture as a comparative example is caused to emit light in two colors.

Description of the reference numerals

21. 22, 23, 24: an LED load; 30: an LED lighting device; 31: a power supply circuit; 32: a selector circuit; 33: a control circuit; 36: a timer; 100: a lighting fixture; c2, C3, C4, C5: a smoothing capacitor; d 1-d 12: an LED; da. Db, Dc, Dd: a diode; l10: an inductor; m3, M4, M5, M6: a switching element.

Detailed Description

(insight underlying the present invention)

The present inventors have found that the following problems occur in the lighting device described in the section "background art".

First, a lighting fixture according to the findings of the present inventors will be described as a comparative example.

Fig. 13 is a diagram showing a configuration of a lighting fixture as a comparative example according to the findings of the present inventors. The lighting apparatus shown in the figure includes a power supply circuit 90, LED loads 91 to 94, and switching elements SW3 to SW 6. The power supply circuit 90 includes switching elements SW1 and SW2 and an inductor L0, and is a DC-DC converter of a so-called step-down chopper type. The switching elements SW1 and SW2 are exclusively controlled to be on. The inductor L0 accumulates and discharges energy supplied from the connection point of the switching elements SW1 and SW 2.

The LED loads 91-94 have different light emission colors. In the figure, the emission colors of the LED loads 91 to 94 are red, green, blue, and white in this order.

The switching elements SW3 to SW6 are controlled to be turned on in an exclusive manner in one cycle.

As the operation of the lighting fixture of this comparative example, an illumination operation in which the lighting is performed in four colors (that is, all colors) and an illumination operation in which the lighting is performed in only two colors out of the four colors will be described.

Fig. 14A is a diagram showing current waveforms in an illumination operation in which the illumination fixture of the comparative example is caused to emit light in four colors. The vertical axis of the graph represents the inductor current IL. The inductor current IL is an output current of the power supply circuit 90 supplied to any one of the LED loads via the inductor L0. The horizontal axis represents time.

As shown in fig. 14A, the LED loads 91 to 94 exclusively emit light so as to make a circuit once in the period Tc. This operation is referred to as sequential lighting. The period Tc is divided into four sections Tr, Tg, Tb, Tw. The sections Tr, Tg, Tb, Tw correspond to red, green, blue, and white, which are emission colors of the LED loads 91 to 94. The period Tc is a very short time to the extent that the human eye does not feel the change. A mixed color obtained by mixing four colors is recognized as illumination light of a single color in human eyes.

Fig. 14B is a diagram showing current waveforms in an illumination operation in which the illumination fixture of the comparative example is caused to emit light in two colors. In the figure, an illumination operation of lighting in two colors is shown in which the LED loads 93 and 94 corresponding to blue and white among the four colors are turned off and the LED loads 91 and 92 corresponding to red and green are turned on. In this case, a mixed color obtained by mixing two colors of red and green is recognized as illumination light of a single color by the human eye.

Further, lighting in two colors in fig. 14B generates a long extinction interval Toff compared to lighting in all colors in fig. 14A, and thus there is a problem that color flicker is likely to occur. Color flicker refers to the following phenomenon: when a fast-moving object is present under the illumination light, each emission color of the LED light sources appears on the object and is perceived by a human. As for the fast moving object, for example, a blade of an electric fan in a living room, a ball in a gym or a movement of hands and feet of a person, and the like. In the case of intense color flicker, people sometimes feel uncomfortable and not fast.

In order to solve the above problem, an LED lighting device according to an aspect of the present invention is an LED lighting device that lights N LED loads having N (N is an integer equal to or greater than 2) emission colors, the LED lighting device including: a power supply circuit that supplies power to the N LED loads; a selector circuit that supplies power from the power supply circuit to the selected LED load by selecting one LED load from the N LED loads; and a control circuit that performs the following sequence control: setting a periodic N time slots in which the selector circuit is caused to select the N LED loads in a round robin manner, wherein the control circuit performs either (i) first control or (ii) second control when receiving a toning instruction instructing to light M (M is an integer smaller than N) LED loads and not to light (N-M) LED loads, in the first control, the selector circuit (32) is caused to select the M LED loads in a round-robin manner in the N time slots, and cause the selector circuit to select at least one of the M LED loads in a plurality of time slots, in the second control, a periodic M number of time slots are set in place of the N number of time slots, and the selector circuit is caused to select the M number of LED loads in a round-robin manner among the M number of time slots.

Thus, there is no unlit time slot, that is, there is no long blanking interval Toff. Therefore, it is possible to make it less likely that color flicker occurs when there is an unlit color during sequential lighting.

Here, the time slot is each time frame obtained by dividing time periodically and dividing one cycle into a plurality of cycles when the plurality of LED loads are sequentially turned on. One time slot is allocated to one LED load as a time frame for lighting.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiments to be described below are all specific preferred examples of the present invention. The numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, connection modes, and the like shown in the following embodiments are examples, and the present invention is not limited thereto. Further, among the components of the following embodiments, components not described in independent claims representing the uppermost concept of the present invention will be described as arbitrary components constituting a more preferable embodiment. The drawings are schematic and do not necessarily indicate a strict dimension.

(embodiment mode 1)

[1.1LED Lighting device and Lighting apparatus Structure ]

First, a configuration example of the lighting fixture 100 including the LED lighting device 30 according to embodiment 1 will be described.

Fig. 1 is a block diagram showing a configuration example of a lighting fixture 100 including an LED lighting device 30 according to embodiment 1. The lighting fixture 100 in the figure includes an AC-DC power supply 10, a light source 20, and an LED lighting device 30.

The AC-DC power supply 10 is connected to, for example, a commercial 100V power supply, and converts input AC power into DC power.

The light source 20 includes LED loads 21-24. The LED loads 21-24 have different light emission colors. The emission colors of the LED loads 21-24 are, for example, R (red), G (green), B (blue), and W (white).

The LED lighting device 30 is a device for lighting a plurality of LED loads 21-24 having different light emission colors. Therefore, the LED lighting device 30 includes the power supply circuit 31, the selector circuit 32, and the control circuit 33.

The power supply circuit 31 is a DC-DC converter that converts DC power from the AC-DC power supply 10 into DC power having different voltages and supplies the converted DC power to the light source 20.

The selector circuit 32 selects one LED load from the plurality of LED loads 21 to 24, and supplies power from the power supply circuit 31 to the selected LED load. For this purpose, the selector circuit 32 includes switching elements M3 to M6. Each of the switching elements M3 to M6 is connected in series with one of the LED loads 21 to 24. For example, in fig. 1, the switching element M3 is connected in series with the LED load 21. The switching element M4 is connected in series with the LED load 22. The switching element M5 is connected in series with the LED load 23. The switching element M6 is connected in series with the LED load 24. These switching elements M3 to M6 are controlled such that, for example, these switching elements M3 to M6 are exclusively turned on. Thus, the LED loads 21-24 emit light exclusively, i.e., one by one.

The control circuit 33 controls the selector circuit 32 so that one LED load is selected from the plurality of LED loads 21 to 24 in a sequentially cyclic manner. Specifically, the control circuit 33 performs the following sequence control: the periodic N time slots are set such that the selector circuit 32 selects the N LED loads in a round robin fashion over the N time slots. Here, N is equal to the number of LED loads 21 to 24, and in fig. 1, N is 4. The sequence control is an illumination operation in which all colors (four colors in fig. 1) are lit.

Further, the control circuit 33 performs one of the first control and the second control when receiving a toning instruction instructing to light M (M is an integer smaller than N) LED loads and not to light (N-M) LED loads.

In (i) the first control, the control circuit 33 causes the selector circuit (32) to select the M LED loads in a round-robin manner in N time slots, and causes the selector circuit 32 to select at least one of the M LED loads in a plurality of time slots. Thus, there is no free slot, and a blanking period longer than the slot is not generated. This makes it difficult for color flicker to occur even when an unlit LED load is present.

In the (ii) second control, the control circuit 33 sets periodic M time slots so that the selector circuit 32 selects M LED loads in a round-robin manner in the M time slots. Thus, there is no free slot, and a blanking period longer than the slot is not generated. This makes it difficult for color flicker to occur even when an unlit LED load is present.

Next, an example of an illumination state in which the LED loads 21 to 24 of four colors are lit in all colors in the above-described sequence control, that is, an example in which light is emitted in all colors will be described.

Fig. 2 is a diagram showing an example of current waveforms in sequential control for causing the lighting fixture 100 according to embodiment 1 to emit light in all colors. In fig. 2, the power supply circuit 31 is a switching power supply including an inductor, and supplies power to the LED loads 21 to 24 via the inductor. The vertical axis of the graph represents the inductor current IL, that is, the current supplied from the power supply circuit 31 to any one of the LED loads. The horizontal axis represents time. This diagram exemplifies sequential control of light emission of all colors (N ═ four colors). The cycle Tc is a cycle in which the four LED loads 21 to 24 are cyclically turned on once, and is divided into four time slots T1 to T4. The four time slots T1 to T4 are allocated to the four LED loads 21 to 24 in a one-to-one manner. The triangular wave in the time slots T1 to T4 represents the waveform of the current supplied from the inductor of the power supply circuit 31. The time slots T1 to T4 are respectively allocated with LED loads 21 to 24 of red, green, blue and white. The period Tc is very short in the human visual sense, and thus the mixed color of the four colors is recognized as one illumination light by the human.

Next, as an example of the illumination state in the first control, an example of light emission in two of four colors will be described.

Fig. 3A is a diagram showing an example of a current waveform in the first control for causing the lighting fixture 100 according to embodiment 1 to emit light in two colors. This figure shows the illumination state in the first control when a toning instruction is received that instructs to light the two LED loads 21, 22 corresponding to red and green and not to light the two LED loads 23, 24 corresponding to blue and white. The period Tc and the time slots T1-T4 in this figure are the same as in FIG. 2. The LED loads 21 and 22 corresponding to red and green are allocated to the time slots T3 and T4 allocated to the LED loads 23 and 24 corresponding to blue and white in fig. 2, so that the time slots T3 and T4 are not empty time slots.

In other words, the control circuit 33 performs the following first control in N slots: causing selector circuit 32 to select at least one of the M LED loads in a plurality of time slots. In fig. 3A, N is 4 and M is 2. The M LED loads are LED loads 21 and 22 corresponding to red and green. The at least one LED load is two LED loads 21, 22 corresponding to red and green. The LED load 21 is selected in two time slots T1 and T3. The LED load 22 is selected in two time slots T2 and T4.

In fig. 3A, the long off interval Toff as in fig. 14B does not exist, and color flicker is less likely to occur. In fig. 3A, the emission colors of the time slots T1 to T4 are red, green, red, and green, but may be red, green, and green, or may be red, green, red, and red, for example.

Next, as an example of the illumination state in the second control, an example of light emission in two of four colors will be described.

Fig. 3B is a diagram showing an example of a current waveform in the second control for causing the lighting fixture 100 according to embodiment 1 to emit light in two colors. This figure shows the same situation as fig. 3A, that is, the lighting state in the second control when a toning instruction is received that instructs to light the two LED loads 21, 22 corresponding to red and green and not to light the two LED loads 23, 24 corresponding to blue and white. The cycle Tc1 in the figure is a cycle in which the two LED loads 21 and 22 corresponding to red and green are cyclically turned on once, and the cycle Tc1 is divided into the time slots T1 and T2. The LED load 21 corresponding to red is assigned to the time slot T1, and the LED load 22 corresponding to green is assigned to the time slot T2.

In other words, the control circuit 33 performs the following second control: m time slots are set in one cycle, causing the selector circuit 32 to select M LED loads in a round robin fashion among the M time slots. In fig. 3B, N is 4 and M is 2. The M LED loads are LED loads 21 and 22 corresponding to red and green.

In fig. 3B, the long off interval Toff as in fig. 14B does not exist, and color flicker is less likely to occur. The period Tc1 in fig. 3B can be set to 1/2 of the period Tc in fig. 3A, for example.

Further, as an example of the illumination state in the second control, another example in which light is emitted in two of the four colors will be described.

Fig. 3C is a diagram showing another example of the current waveform in the second control for causing the lighting fixture 100 according to embodiment 1 to emit light in two colors. This figure shows the same situation as fig. 3A, that is, the lighting state in the second control when a toning instruction is received that instructs to light the two LED loads 21, 22 corresponding to red and green and not to light the two LED loads 23, 24 corresponding to blue and white. The cycle Tc2 in the figure is a cycle in which the two LED loads 21 and 22 corresponding to red and green are cyclically turned on once, and the cycle Tc2 is divided into the slots T1 and T2. The LED load 21 corresponding to red is assigned to the time slot T1, and the LED load 22 corresponding to green is assigned to the time slot T2.

In other words, the control circuit 33 performs the following second control: m time slots are set in one cycle, causing the selector circuit 32 to select M LED loads in a round robin fashion among the M time slots. In fig. 3C, N is 4 and M is 2. The M LED loads are LED loads 21 and 22 corresponding to red and green.

In fig. 3C, the long off interval Toff as in fig. 14B does not exist, and color flicker is less likely to occur. The period Tc2 in fig. 3C may be the same as the period Tc in fig. 3A, for example. In fig. 3A to 3C, an example of emitting light in two colors of red and green is shown, but a combination of other colors may be used.

Next, as an example of the illumination state in the first control, an example of light emission in three colors out of four colors will be described. Fig. 4A is a diagram showing an example of current waveforms in the first control for causing the lighting fixture 100 according to embodiment 1 to emit light in three colors. This figure shows the illumination state in the first control when a toning instruction is received that instructs to turn on three

LED loads

21, 22, 24 corresponding to red, green, and white and not turn on one LED load 23 corresponding to blue. The period Tc and the time slots T1-T4 in this figure are the same as in FIG. 2. In fig. 4A, the LED load 24 corresponding to white is allocated to the time slot T3 allocated to the LED load 23 corresponding to blue, so that the time slot T3 is not an empty time slot.

In other words, the control circuit 33 performs the following first control in N slots: causing selector circuit 32 to select at least one of the M LED loads in a plurality of time slots. In fig. 4A, N is 4 and M is 3. The M LED loads are LED

loads

21, 22, 24 corresponding to red, green, and white. The at least one LED load described above is the LED load 24 corresponding to white. The LED load 24 is selected in two time slots T3, T4.

In fig. 4A, the long off interval Toff as in fig. 14B does not exist, and color flicker is less likely to occur. In fig. 4A, the emission colors of the time slots T1 to T4 are red, green, white, and white, but may be red, green, red, and white, or may be red, green, and white, for example.

Next, as an example of the illumination state in the second control, an example of light emission in three colors out of four colors will be described.

Fig. 4B is a diagram showing an example of current waveforms in the second control for causing the lighting fixture 100 according to embodiment 1 to emit light in three colors. This figure shows the same situation as fig. 4A, that is, the lighting state in the second control when a toning instruction is received that instructs to turn on three

LED loads

21, 22, and 24 corresponding to red, green, and white and not turn on one LED load 23 corresponding to blue. The cycle Tc2 in the figure is a cycle in which the three

LED loads

21, 22, and 24 corresponding to red, green, and white are cyclically turned on once, and the cycle Tc2 is divided into slots T1 to T3. The LED loads 21, 22, and 24 corresponding to red, green, and white are assigned to the time slots T1 to T3.

In other words, the control circuit 33 performs the following second control: m time slots are set in one cycle, causing the selector circuit 32 to select M LED loads in a round robin fashion among the M time slots. In fig. 4B, N is 4 and M is 3. The M LED loads are LED

loads

21, 22, 24 corresponding to red, green, and white.

In fig. 4B, the long off interval Toff as in fig. 14B does not exist, and color flicker is less likely to occur. The period Tc2 in fig. 4B can be set to 3/4 of the period Tc in fig. 3A, for example. Fig. 4A and 4B show examples of light emission in three colors of red, green, and white, but other combinations of colors may be used.

Next, a more specific circuit example of the lighting fixture 100 including the LED lighting device 30 will be described.

Fig. 5 is a diagram showing an example of a circuit configuration of a lighting fixture 100 including the LED lighting device 30 according to embodiment 1. As shown in the drawing, the lighting fixture 100 includes a light source 20 and an LED lighting device 30. However, the AC-DC power supply 10 shown in fig. 1 is omitted in fig. 5.

The LED load 21 in the light source 20 is connected in series to the switching element M3, and the on/off of the switching element M3 controls the lighting of the LED load 21. The longer the on time of the switching element M3, the more current flows through the LED load 21, and the more light is emitted.

As a specific circuit example, the LED load 21 of fig. 5 includes LEDs d1 to d3, a smoothing capacitor C2 connected in parallel to the LEDs d1 to d3, a diode Da for preventing reverse flow connected in series to a parallel circuit including the LEDs d1 to d3 and the smoothing capacitor C2, and a resistor R2 for discharging when the power supply is off.

The LEDs d1 to d3 are LED light emitting elements of the same emission color connected in series, and are connected in series to the switching element M3.

The smoothing capacitor C2 smoothes the inductor current supplied from the inductor L10 via the diode Da.

The diode Da prevents a reverse flow of current from the smoothing capacitor C2 to the inductor L10. That is, the diode Da supplies the electric charge charged in the smoothing capacitor C2 only to the LEDs d1 to d 3.

The resistor R2 has a high resistance value for discharging the electric charge of the smoothing capacitor C2 after the power supply is changed from the on state to the off state.

The LED loads 22-24 have similar structures except that they have different light emission colors from the LED load 21. The LED load 21 may be configured without the smoothing capacitor C2 and the diode Da for preventing the backflow. The same applies to the LED loads 22-24.

Fig. 5 shows an example of a step-down chopper circuit as the power supply circuit 31 in the LED lighting device 30. Specifically, the power supply Circuit 31 includes a regulator 34, an HVIC (High Voltage Integrated Circuit) 35, input resistors R6 and R7, switching elements M1 and M2, and an inductor L10.

The regulator 34 receives direct-current power from the AC-DC power supply 10, and supplies a stabilized power supply voltage to the HVIC 35 and the control circuit 33.

The HVIC 35 supplies gate signals to the switching elements M1 and M2 via the input resistors R6 and R7 under the control of the control circuit 33. The gate signals of the switching elements M1, M2 are activated in an exclusive manner at high speed and periodically.

The switching elements M1 and M2 are high-side transistors and low-side transistors for alternately connecting the DC voltage supplied from the AC-DC power supply 10 and the ground level to the inductor L10.

The inductor L10 accumulates and discharges energy in response to the switching action of the switching elements M1, M2.

The selector circuit 32 includes input resistors R8 to R11 and switching elements M3 to M6.

The switching element M3 is connected in series with the LED load 21. A gate signal instructing on and off is input from the control circuit 33 to the gate of the switching element M3 via the input resistor R8. The switching element M3 is turned on and off according to the gate signal.

The switching elements M4 to M6 are also the same as the switching element M3.

The control circuit 33 may be constituted by an MCU (Micro Controller Unit or Micro Computer Unit) having a processor, a memory, and a timer 36 built therein. The timer 36 measures various periodic times. For example, the measurement is performed for a cycle of one selection round of the plurality of LED loads 21 to 24.

[1.2 actions of LED Lighting device and Lighting apparatus ]

Next, an operation example of the lighting fixture 100 including the LED lighting device 30 according to embodiment 1 will be described.

First, an operation example when light is emitted in four of the four colors, that is, when light is emitted in all the colors will be described.

Fig. 6 is a diagram showing current waveforms and voltage waveforms of respective sections in the sequential control of emitting light of all colors in the lighting fixture 100 according to embodiment 1. The horizontal axis of the figure is a time axis. The vertical axis represents the current or voltage of each part. The inductor current IL represents a current flowing in the inductor L10, that is, a current supplied from the power supply circuit 31 to any one of the LED loads. The inductor current IL corresponds to fig. 2.

The gate voltage V0 represents a voltage input from the control circuit 33 to the gate of the switching element M1 via the HVIC 35. When the gate voltage V0 is at a high level, the switching element M1 is turned on. The high-level section of the gate voltage V0 is equal to the gradient rise section of the triangular wave of the inductor current IL. In the interval where the gate voltage V0 is high, the inductor current IL gradually increases. At this time, the inductor L10 accumulates electric energy as magnetic energy. When the gate voltage V0 is low, the switching element M1 is turned off. Immediately after the switching element M1 is switched from the on state to the off state, the inductor L10 discharges the stored energy, that is, supplies the inductor current IL to the LED load 21 while reducing the inductor current IL to 0 by the back electromotive force of the inductor L10. As a result, the inductor current IL is a triangular wave in the figure. The length of the bottom side of the triangular wave is a power supply section for supplying power from the power supply circuit 31 to the LED load. The power supply interval is longer than the high level interval of the gate voltage V0. The power supply interval from the power supply circuit 31 to the LED load is equal to the interval of one triangular wave.

The gate voltage Vr represents a voltage input from the control circuit 33 to the gate of the switching element M3. When the gate voltage Vr is at the high level, the switching element M3 is turned on, that is, the corresponding LED load 21 is selected. The high level section of the gate voltage Vr is controlled to be a period including the high level section of the gate voltage V0 and including a triangular wave of the corresponding inductor current IL. The gate voltages Vg, Vb, Vw are also the same as the gate voltage Vr. The pulse widths of the gate voltages Vr, Vg, Vb, and Vw are set to be equal to or larger than the width of the bottom side of the triangular wave of the inductor current IL and smaller than the width of the slot. In addition, four dead time periods are provided between high level sections of the gate voltages Vr, Vg, Vb, Vw, and these four dead time periods are all at a low level.

The LED current Ir indicates the current flowing through the LEDs d1 to d3 in the LED load 21. After the power supply interval, that is, after the power supply from the power supply circuit 31 to the LED load 21 is completed, the LED current Ir is not zero, and continues to flow while decreasing. This depends on the smoothing capacitor C2 and the diode Da for preventing the reverse flow.

The LED currents Ig, Ib, Iw are also the same as the LED current Ir.

As shown in fig. 6, in the time slots T1 to T4, the LED loads 21 to 24 corresponding to red, green, blue, and white are selected, respectively. In other words, the control circuit 33 performs the following sequential control: the periodic N time slots are set such that the selector circuit 32 selects the N LED loads in a round robin fashion over the N time slots. Here, N is 4.

In the lighting fixture 100, the color of the illumination light is adjusted by changing the ratio of the brightnesses of the plurality of emission colors. Specifically, in fig. 6, the control circuit 33 can perform the toning by changing the ratio of the four pulse widths of the gate voltage V0 in the time slots T1 to T4. In the lighting fixture 100, the brightness is changed while the ratio of the brightness of the plurality of emission colors is kept constant, thereby realizing dimming for adjusting the brightness of the illumination light. Specifically, in fig. 6, the control circuit 33 can perform dimming by increasing and decreasing the four pulse widths of the gate voltage V0 while keeping the ratio of the four pulse widths of the gate voltage V0 of the time slots T1 to T4 fixed.

In the example shown in fig. 6, the switching element M1 of the power supply circuit 31 is controlled to be on during the period in which any one of the LED loads is selected by the selector circuit 32. That is, the switching operation of the power supply circuit 31 as a switching power supply is synchronized with the selection operation of the selector circuit 32.

Next, an operation example when light emission is performed with two colors in the first control will be described.

Fig. 7A is a diagram showing current waveforms and voltage waveforms of respective portions in the first control for causing the lighting fixture 100 according to embodiment 1 to emit light in two colors. The inductor current IL of fig. 7A corresponds to fig. 3A. In fig. 7A, gate voltages Vr to Vw and LED currents Ir to Iw are different from those in fig. 6. Hereinafter, the following description will focus on the differences.

The gate voltage Vr is activated not only in the slot T1 but also in the slot T3. Thereby, the LED load 21 corresponding to red is selected twice within the period Tc.

The gate voltage Vg is activated not only in the time slot T2 but also in the time slot T4. Thus, the LED load 22 corresponding to green is selected twice in the period Tc.

The gate voltages Vb and Vw are inactive in all time slots. Thus, the LED loads 23 corresponding to blue and white are not selected at once within the period Tc.

In both time slots T1, T3, the LED current Ir peaks based on the inductor current IL.

In both time slots T2, T4, the LED current Ig peaks based on the inductor current IL.

The LED currents Ib and Iw do not flow in all time slots.

Thus, in fig. 7A, when a toning instruction instructing to light M (two, here, red and green) LED loads and not to light (N-M) (two, here, blue and white) LED loads is received, the control circuit 33 performs the following first control in four time slots: causing the selector circuit 32 to select at least one of the M (here, two, red and green) LED loads in a plurality of time slots.

Next, an operation example when light emission is performed with two colors in the second control will be described.

Fig. 7B is a diagram showing current waveforms and voltage waveforms of respective portions in the second control for causing the lighting fixture 100 according to embodiment 1 to emit light in two colors. The inductor current IL of fig. 7B corresponds to fig. 3B. In fig. 7B, compared with fig. 7A, the waveforms are substantially the same as those in fig. 7A, and the slot structure is different. Hereinafter, the following description will focus on the differences.

The period Tc1 corresponds to, for example, 1/2 of the period Tc in fig. 7A. The period Tc1 is divided into two slots T1, T2.

In this way, in fig. 7B, when a toning instruction is received that instructs to light M (here, two of red and green) LED loads and not to light (N-M) (here, two of blue and white) LED loads, the control circuit 33 performs the following second control: the periodic M time slots are set such that the selector circuit 32 selects M LED loads in a round robin fashion among the M time slots.

As described above, the LED lighting device 30 according to embodiment 1 lights N LED loads 21 to 24 having N emission colors (N is an integer of 2 or more), and includes: a power supply circuit 31 for supplying power to the N LED loads 21-24; a selector circuit 32 that supplies power from the power supply circuit 31 to one of the N LED loads 21 to 24 by selecting the selected LED load; and a control circuit 33 that performs the following sequence control: the periodic N time slots are set such that the selector circuit 32 selects the N LED loads in a round robin fashion over the N time slots. Upon receiving a toning instruction instructing to turn on M (M is an integer smaller than N) LED loads and not turn on (N-M) LED loads, the control circuit 33 performs either (i) a first control of causing the selector circuit 32 to cyclically select the M LED loads in the N time slots and causing the selector circuit 32 to select at least one of the M LED loads in a plurality of time slots, or (ii) a second control of setting periodic M time slots and causing the selector circuit 32 to cyclically select the M LED loads in the M time slots.

This makes it possible to prevent color flicker from occurring when there is an unlit color during sequential lighting.

Here, the power supply circuit 31 may be a switching power supply including an inductor L10, and supplies power to the LED loads 21 to 24 via an inductor L10.

This enables the power supply circuit 31 to be reduced in size, efficiency, and cost.

Here, the control circuit 33 synchronizes the switching operation of the power supply circuit 31 with the selection operation of the selector circuit 32.

This can further reduce the size, efficiency, and cost of the power supply circuit 31.

Here, the control circuit 33 may perform the first control when receiving the above-described toning instruction.

This allows the existence of unlit colors while maintaining the cycle and the number of divided slots.

Here, the control circuit 33 may perform the second control when receiving the above-described toning instruction.

Thus, by changing the number of divided time slots to M, the presence of unlit colors can be easily allowed.

The lighting fixture 100 according to embodiment 1 includes an LED lighting device 30 and a plurality of LED loads 21 to 24.

Here, each of the plurality of LED loads may include one or more LEDs, a smoothing capacitor connected in parallel to the one or more LEDs, and a diode connected in series to a parallel circuit including the one or more LEDs and the smoothing capacitor to prevent a backflow.

The control circuit 33 may be configured to execute only one of the (i) first control and the (ii) second control, or may be configured to be capable of executing both types of control and execute one of the controls alternatively.

(embodiment mode 2)

Next, the LED lighting device 30 and the lighting fixture 100 according to embodiment 2 will be described.

In the present embodiment, the following example is explained: when the lighting fixture 100 according to embodiment 1 receives a toning instruction instructing to light M (M is an integer smaller than N) LED loads and not to light (N-M) LED loads, the brightness (light flux amount) in one of the (i) first control and the (ii) second control is made the same as the brightness (light flux amount) in the (iii) sequential control of allowing unlit colors.

[2.1 structures of LED Lighting device and Lighting apparatus ]

The configuration of the lighting fixture 100 according to embodiment 2 may be the same as that of the lighting fixture in fig. 1 and 5. However, the control circuit 33 causes the selector circuit 32 to perform different control. Hereinafter, the following description will focus on the differences.

The control circuit 33 sets the effective value of the current of each of the M LED loads assumed when the control of (iii) is performed such that the M LED loads are cyclically selected in M slots of the N slots and any one of the N-M LED loads is not selected in the N-M slots, to be the same as the effective value of the current of each of the M LED loads in the control of either one of (i) the first control and (ii) the second control. For example, when a toning instruction is received that instructs to light M (M is an integer smaller than N) LED loads and not to light (N-M) LED loads, the control circuit 33 transitions from performing control of (iii) to control of (i) or (ii). In this case, the brightness in the control of (iii) can be made the same as the brightness in the control of (i) or (ii).

[2.2 actions of LED Lighting device and Lighting apparatus ]

Next, an operation example of the lighting fixture 100 including the LED lighting device 30 according to embodiment 2 will be described.

Fig. 8A is a diagram showing an example of a waveform of a current in sequence control including unlit colors according to embodiment 2. That is, fig. 8A shows an example of the waveform of (iii) described above, which corresponds to a toning instruction for instructing to turn on M (here, two of red and green) LED loads and not turn on (N-M) (here, two of blue and white) LED loads.

Upon receiving the toning instruction, the control circuit 33 performs (i) the first control or (ii) the second control after the control of (iii) is temporarily performed or after the current values L1 and Lav in the case where the control of (iii) is assumed to be performed are calculated. The current value L1 of fig. 8A is the peak value of the inductor current IL. The current value Lav is an effective value (here, an average value is also possible) of the inductor current IL. The control circuit 33 controls so that the effective value in (iii) is the same as that in (i) the first control or (ii) the second control.

Fig. 8B is a diagram showing an example of a waveform of a current in (i) the first control corresponding to fig. 8A. The current value L2 of fig. 8B is the peak value of the inductor current IL. The current value Lav is an effective value (average value) of the inductor current IL. The control circuit 33 sets (i) the peak value L2 in the first control so that the effective value Lav in fig. 8B is the same as the effective value Lav in fig. 8A. The peak value L2 is proportional to the pulse width of the gate voltage V0 shown in fig. 7A. The control circuit 33 determines the pulse width of the gate voltage V0 corresponding to the effective value Lav and the peak value L2.

In fig. 8A and 8B, the effective value Lav, the peak value L1, and the peak value L2 are not limited to one, and the current values Lav, L1, and L2 for red and the current values Lav, L1, and L2 for green are actually processed separately.

Fig. 8C is a diagram showing an example of a waveform of a current in the (ii) second control corresponding to fig. 8A. Fig. 8C is the same as fig. 8B except that the slot structure is different from that of fig. 8B.

As described above, in the LED lighting device 30 according to embodiment 2, the control circuit 33 makes the effective values of the M LED loads assumed when the control of (iii) is performed the same as the effective values of the M LED loads in the control of either one of (i) the first control and (ii) the second control, and in the control of (iii), the selector circuit 32 is controlled so that the M LED loads are cyclically selected in the M slots of the N slots and any one LED load is not selected in the N-M slots.

Thereby, the brightness (light flux amount) in the sequence control of (iii) can be made the same as the brightness (light flux amount) in the (i) first control or the (ii) second control.

(embodiment mode 3)

Next, the LED lighting device 30 and the lighting fixture 100 according to embodiment 3 will be described. In embodiment 3, the following example will be explained: in the lighting fixture 100 of embodiment 2, a transition period is also provided between the sequence control of (iii) and the first control of (i).

[3.1 structures of LED Lighting device and Lighting apparatus ]

The configuration of the lighting fixture 100 according to embodiment 3 may be the same as that of the lighting fixture in fig. 1 and 5. However, the control circuit 33 causes the selector circuit 32 to perform different control. Hereinafter, the following description will focus on the differences.

When a toning instruction instructing to light M (M is an integer smaller than N) LED loads and not to light (N-M) LED loads is received, the control circuit 33 temporarily performs the sequence control of (iii) before the first control of (i). The control circuit 33 sets a transition period from the end of the control of (iii) to the start of the first control of (i). During the transition period, the control circuit 33 performs control of making the respective effective values of the M LED loads the same and generating at least one intermediate state between the lighting state in the sequential control of (iii) and the lighting state in (i) the first control. This makes it possible to smoothly transit from the illumination state in the sequence control of (iii) to the illumination state in the first control of (i).

[3.2 actions of LED Lighting device and Lighting apparatus ]

Next, an operation example of the lighting fixture 100 including the LED lighting device 30 according to embodiment 3 will be described.

Fig. 9 is a diagram showing an example of the waveform of the current in the sequence control, the transition period, and the first control according to embodiment 3. Fig. 9 (a) is the same as fig. 8A showing waveforms in the sequence control. Fig. 9 (c) is the same as fig. 8B showing waveforms in the first control. Fig. 9 (b) shows an example of a waveform in the intermediate state of the transition period, and shows the intermediate state that changes stepwise. At least one intermediate state is sufficient, and for example, three or four intermediate states may be used.

In fig. 9 (b), the control circuit 33 reduces the peak value of the inductor current IL from L1 to L2 in stages in the time slots T1 and T2 in lighting. The control circuit 33 increases the peak value of the inductor current IL stepwise from 0 to L2 in the unlit time slots T3 and T4. In addition, the control circuit 33 performs control in (b) and (c) so that the effective value (average value) Lav of the inductor current IL is kept constant.

The effective values Lav, peak value L1, and peak value L2 are not limited to one, and the current values Lav, L1, and L2 for red and the current values Lav, L1, and L2 for green are processed individually.

As described above, in the LED lighting device 30 according to embodiment 3, the control circuit 33 performs the following control: the control of (iii) is performed temporarily before the first control of (i), a transition period from the end of the control of (iii) to the start of the first control of (i) is provided, and the effective values of the M LED loads are made the same in the transition period and at least one intermediate state between the lighting state in the control of (iii) and the lighting state in the first control is generated.

As a result, the brightness (light flux amount) in the sequence control of (iii) can be made the same as the brightness (light flux amount) in the first control of (i), and the transition from (iii) to (i) can be made smoothly.

(embodiment mode 4)

Next, the LED lighting device 30 and the lighting fixture 100 according to embodiment 4 will be described. In embodiment 4, the following example is explained: in the lighting fixture 100 of embodiment 2, a transition period is also provided between the sequence control of (iii) and the second control of (ii).

[4.1 structures of LED Lighting device and Lighting apparatus ]

The configuration of the lighting fixture 100 according to embodiment 4 may be the same as that of the lighting fixture in fig. 1 and 5. However, the control circuit 33 causes the selector circuit 32 to perform different control. Hereinafter, the following description will focus on the differences.

When a toning instruction instructing to light M (M is an integer smaller than N) LED loads and not to light (N-M) LED loads is received, the control circuit 33 temporarily performs the sequence control of (iii) before the second control of (ii). The control circuit 33 sets a transition period from the end of the control of (iii) to the start of the second control of (ii). During the transition period, the control circuit 33 performs control of making the effective values of the currents of the respective M LED loads the same and generating at least one intermediate state between the lighting state in the sequence control of (iii) and the lighting state in the second control of (ii). This makes it possible to smoothly transit from the illumination state in the sequence control of (iii) to the illumination state in the second control of (ii).

[4.2 actions of LED Lighting device and Lighting apparatus ]

Next, an operation example of the lighting fixture 100 including the LED lighting device 30 according to embodiment 4 will be described.

Fig. 10 is a diagram showing an example of the waveform of the current in the sequence control, the transition period, and the second control according to embodiment 4. Fig. 10 (a) is the same as fig. 8A showing waveforms in the sequence control. Fig. 10 (C) is substantially the same as fig. 8C showing waveforms in the second control. Fig. 10 (b) shows an example of a waveform in the intermediate state of the transition period, and shows the intermediate state that changes stepwise. At least one intermediate state is sufficient, and for example, three or four intermediate states may be used.

In fig. 10 (b), the control circuit 33 reduces the peak value of the inductor current IL from L1 to L2 in stages in the time slots T1 and T2 in lighting. Meanwhile, the control circuit 33 reduces the time width of each slot to 0 in stages in the unlit slots T3 and T4. The control circuit 33 controls (b) and (c) so that the effective value (average value) Lav of the inductor current IL is kept constant.

As described above, in the LED lighting device 30 according to embodiment 4, the control circuit 33 performs the following control: the control of (iii) is performed temporarily before the second control of (ii), a transition period from the end of the control of (iii) to the start of the second control of (ii) is provided, and at least one intermediate state in which the time of (N-M) time slots out of the N time slots is gradually shorter than the time of the N time slots in the control of (iii) is generated in the transition period.

As a result, the brightness (light flux amount) in the sequence control of (iii) can be made the same as the brightness (light flux amount) in the second control of (ii), and the transition can be smoothly performed without giving a sense of discomfort to the human eye in the transition from (iii) to (ii).

(embodiment 5)

Next, the LED lighting device 30 and the lighting fixture 100 according to embodiment 5 will be described. In embodiment 5, the following example is explained: compared to embodiment 4, the period Tc in the second control (ii) is made the same as the period Tc in the sequence control (iii), the time width of the time slot is extended, and the power supply interval from the power supply circuit 31 to the LED load is extended. Here, the power supply section from the power supply circuit 31 to the LED load corresponds to the length of the bottom side of the triangular wave of the inductor current IL in fig. 3A to 3C.

[5.1 structures of LED Lighting device and Lighting apparatus ]

The configuration of the lighting fixture 100 according to embodiment 5 may be the same as that of the lighting fixture in fig. 1 and 5. However, the control circuit 33 causes the selector circuit 32 to perform different control. Hereinafter, the following description will focus on the differences.

When a toning instruction instructing to light M (M is an integer smaller than N) LED loads and not to light (N-M) LED loads is received, the control circuit 33 temporarily performs the sequence control of (iii) before the second control of (ii). The control circuit 33 sets a transition period from the end of the control of (iii) to the start of the second control of (ii). During the transition period, the control circuit 33 performs control of making the respective effective values of the M LED loads the same and generating at least one intermediate state between the lighting state in the sequential control of (iii) and the lighting state in the second control.

The control circuit 33 makes the period Tc including M slots in the (ii) second control the same as the period Tc including N slots in the sequential control of (iii). Thus, the time of each of the M time slots is longer than the time of each of the N time slots. At the same time, the control circuit 33 makes the power supply time of each of the M slots longer in the (ii) second control than the power supply time corresponding to the N slots in the (iii) sequence control.

[5.2 actions of LED Lighting device and Lighting apparatus ]

Next, an operation example of the lighting fixture 100 including the LED lighting device 30 according to embodiment 5 will be described.

Fig. 11 is a diagram showing an example of the waveform of the current in the sequence control, the transition period, and the second control according to embodiment 5. Fig. 11 (a) is the same as fig. 8A showing waveforms in the sequence control. Fig. 11 (C) is the same as fig. 8C showing waveforms in the second control. Fig. 11 (b) shows an example of a waveform in the intermediate state of the transition period, and shows the intermediate state that changes stepwise. At least one intermediate state is sufficient, and for example, three or four intermediate states may be used.

In fig. 11 (b), the control circuit 33 reduces the peak value of the inductor current IL from L1 to L2 in stages and lengthens the power supply time in stages in the time slots T1 and T2 in lighting. At the same time, the control circuit 33 increases the time width of each of the slots T1 and T2 in lighting up to Tc/2 in stages. In addition, the control circuit 33 reduces the time width of each slot to 0 in stages in the unlit slots T3 and T4. At this time, the control circuit 33 controls the effective value (average value) Lav of the inductor current IL to be constant in fig. 11 (b) and (c).

In fig. 11 (b) and (c), the control circuit 33 needs to reduce the slope of the slope rise in the triangular wave of the inductor current IL in order to reduce the peak value of the inductor current IL, extend the power supply time, and keep the effective value (average value) Lav constant. In order to decrease the slope, the control circuit 33 may decrease the power supply voltage of the power supply circuit 31, or may increase the inductance value by configuring the inductor L10 with a variable inductor.

As described above, in the LED lighting device 30 according to embodiment 5, the control circuit 33 makes the period including M slots in the second control (ii) the same as the period Tc including N slots in the control (iii), and makes the power feeding time of each of the M slots in the second control (ii) longer than the power feeding time corresponding to the N slots in the control (iii).

Here, the control circuit 33 may set the supply voltage from the power supply circuit in M time slots in the (ii) second control to be smaller than the supply voltage in N time slots in the (iii) control.

Thus, the control circuit 33 can easily keep the effective value (average value) of the supply current constant in the control of (iii) and the second control of (ii).

Here, the control circuit 33 may temporarily perform the control of (iii) before the second control of (ii), provide a transition period from the end of the control of (iii) to the start of the second control of (ii), and transition through at least one intermediate state in which the supply-time voltage from the power supply circuit in the M time slots in the second control of (ii) is gradually reduced from the supply voltage in the N time slots in the control of (iii) in the transition period.

Here, the control circuit 33 may gradually extend the time of each of the M time slots as compared with the time of each of the N time slots in at least one intermediate state, gradually extend the power supply time of the power supply from the power supply circuit among the M time slots as compared with the power supply time of the N time slots in the control of (iii), and gradually shorten the time of the N-M time slots among the N time slots as compared with the time of the N time slots in the control of (iii) in at least one intermediate state.

The period Tc and the period Tc1 may be varied at a speed that is not noticeable to humans. For example, the frequency, which is the inverse of the cycle Tc of the one-time cycle lighting, may be set to 100Hz or more.

Here, "a period that changes at a speed that is imperceptible to a human" means "making a human imperceptible to flicker". As for the countermeasure against flickering of LED lighting, for example, the standard is shown in "the policy action for modification of the electrical product safety law" (executed from 24 years, 7 months, and 1 day) "(issued by the product safety department of the business distribution group of the ministry of economic industry), which is a document for explaining the electrical product safety law (PSE). In the "flicker (flicker) measure of light output" on page 28 of this description document, the frequency of bringing about the effect equivalent to "the light output is an output that flicker is not sensed" is explained as follows. That is, in this explanatory document, it is explained that the condition that "the light output is the light output in which flicker is not sensed" is satisfied is either one of the following conditions (1) and (2): (1) the repetition frequency is above 100Hz and the light output has no missing part; (2) the repetition frequency is above 500 Hz.

In the lighting fixture 100 of the present embodiment, since it is considered that there is no loss in light output in the examples of fig. 6, 7A, and 7B, it is considered that the above (1) is satisfied. In this case, the frequency, which is the reciprocal of the one-cycle lighting period, may be set to 100Hz or more.

In addition, although the embodiments have been described with N being 4 and M being 2, N may be a number other than 4, and M may be a number other than 2. As an example of M ═ 2, an example in which light is emitted in two colors of red and green has been described, but a combination of other colors may be used.

(embodiment mode 6)

In embodiment 6, an example of a lighting fixture 100 including the LED lighting device 30 according to each of the above embodiments will be described with reference to fig. 12A to 12C.

Fig. 12A is a diagram showing an example of the appearance of a lighting fixture 100 including the LED lighting device 30 according to each embodiment. Fig. 12A shows an external appearance of a ceiling lamp 100a as an example of the lighting fixture 100.

The ceiling lamp 100a includes a circuit box 101a, a lamp body 102a, and a wiring 103 a. The circuit box 101a is a case that houses all or a part of the LED lighting device 30 according to each of the above embodiments. The lamp body 102a is a lamp body to which the light source 20 is mounted. The wiring 103a electrically connects the circuit box 101a and the light source 20 in the lamp body 102 a.

Fig. 12B is a diagram showing another example of the appearance of the lighting fixture 100 including the LED lighting device 30 according to each embodiment. Fig. 12B shows an external appearance of a spotlight 100B as an example of the lighting fixture 100.

The spotlight 100b includes a circuit box 101b, a lamp body 102b, and a wiring 103 b. These circuit box 101b, lamp body 102b, and wiring 103b are the same as the circuit box 101a, lamp body 102A, and wiring 103a of fig. 12A.

Fig. 12C is a diagram showing another example of the appearance of the lighting fixture 100 including the LED lighting device 30 according to each embodiment. Fig. 12C shows an external appearance of a spotlight 100C as an example of the lighting fixture 100.

The spotlight 100c includes a circuit box 101c and a lamp body 102 c. These components are also the same as the circuit box 101a and the lamp body 102b in fig. 12A.

Also in embodiment 6, the same effects as those in the above-described embodiments can be obtained.

The LEDs d1 to D12 in the Light source 20 may be not only so-called Light Emitting diodes but also solid state Light Emitting elements such as Organic EL Light Emitting elements (OLEDs) and laser Light Emitting elements.

The LED lighting device 30 and the lighting fixture 100 according to the present invention have been described above based on the embodiments, but the present invention is not limited to the embodiments. The present invention is not limited to the embodiments described above, and various modifications and other embodiments may be made without departing from the spirit and scope of the present invention.

Claims

1. An LED lighting device for lighting N LED loads having N emission colors, comprising:

a power supply circuit that supplies power to the N LED loads;

a selector circuit that supplies power from the power supply circuit to the selected LED load by selecting one LED load from the N LED loads; and

a control circuit which performs the following sequence control: setting N time slots periodically, causing the selector circuit to select the N LED loads in a round robin fashion among the N time slots,

wherein the control circuit performs either (i) first control or (ii) second control when receiving a toning instruction instructing to light M LED loads and not to light (N-M) LED loads,

in the first control, the selector circuit is caused to select the M LED loads in the N time slots in a round-robin manner, and the selector circuit is caused to select at least one of the M LED loads in a plurality of time slots,

in the second control, a periodic M number of time slots are set so that the selector circuit selects the M LED loads in a round-robin manner among the M number of time slots,

wherein N is an integer of 2 or more, M is an integer smaller than N, and the LED is a light emitting diode.

2. The LED lighting device according to claim 1,

the power supply circuit is a switching power supply including an inductor, and supplies power to a plurality of the LED loads via the inductor.

3. The LED lighting device according to claim 2,

the control circuit synchronizes a switching operation of the power supply circuit with a selection operation of the selector circuit.

4. The LED lighting device according to any one of claims 1 to 3,

the control circuit performs the first control when receiving the toning instruction.

5. The LED lighting device according to any one of claims 1 to 3,

the control circuit performs the second control when receiving the toning instruction.

6. The LED lighting device according to any one of claims 1 to 3,

it is assumed that the control circuit performs control of (iii) below: control the selector circuit such that the M LED loads are selected in a round robin manner in M of the N time slots, none of the LED loads being selected in (N-M) time slots,

the current effective values of the M LED loads in the control of (iii) are assumed to be the same as the current effective values of the M LED loads in the control of either one of the first control and the second control.

7. The LED lighting device according to claim 6,

the control circuit temporarily performs the control of (iii) before the first control,

(iv) the control circuit sets a transition period from the end of the control of (iii) to the start of the first control,

during the transition, the control circuit performs control of making the effective values of the respective M LED loads the same and generating an intermediate state between the lighting state in the control of at least one of (iii) and the lighting state in the first control.

8. The LED lighting device according to claim 6,

the control circuit temporarily performs the control of (iii) before the second control,

the control circuit sets a transition period from the end of the control of (iii) to the start of the second control,

during the transition, the control circuit performs control of generating at least one intermediate state in which the time of the (N-M) time slots of the N time slots becomes gradually shorter than the time of the N time slots of the control of (iii).

9. The LED lighting device according to claim 6,

the control circuit makes a cycle including M slots in the second control the same as a cycle including N slots in the control of (iii),

the control circuit makes the power supply time of each of the M time slots in the second control longer than the power supply time corresponding to the N time slots in the control of (iii).

10. The LED lighting device according to claim 9,

the control circuit makes the supply voltage from the power supply circuit in M time slots in the second control smaller than the supply voltage in N time slots in the control of (iii).

11. The LED lighting device according to claim 9,

during the transition, the control circuit makes a transition via at least one intermediate state in which the supply-time voltage from the power supply circuit in the M time slots in the second control is made gradually smaller than the supply voltage in the N time slots in the control of (iii).

12. The LED lighting device according to claim 11,

(iv) the control circuit in the at least one intermediate state gradually extends the time of each of the M time slots as compared to the time of each of the N time slots, while gradually extending the power supply time of the M time slots to which power is supplied from the power supply circuit as compared to the power supply time of the N time slots in the control of (iii),

(iv) the control circuitry in the at least one intermediate state progressively shortens the time of (N-M) of the N time slots compared to the time of N time slots in the control of (iii).

13. A lighting fixture is provided with:

the LED lighting device according to claim 1; and

a plurality of said LED loads.

14. The lighting apparatus of claim 13,

each of the plurality of LED loads has:

more than one LED;

a smoothing capacitor connected in parallel with the one or more LEDs; and

and a diode for preventing a reverse current, which is connected in series with a parallel circuit including the one or more LEDs and the smoothing capacitor.