JP7463844B2 - Lighting devices and luminaires - Google Patents

Description

This disclosure relates to lighting devices and lighting fixtures.

Patent Document 1 discloses a dimmer that receives a corresponding dimming signal from a dimmer console that periodically transmits multi-channel dimming data via communication and controls dimming. In this dimmer, the receiving side measures the time until the next dimming data reception by itself, and determines the number of dimming operations and the dimming value after receiving the dimming data, and is provided with a receiving side dimming means that gradually dims the light to the target dimming value determined within that time.

Patent No. 5008463

In the method of Patent Document 1, the sender of the dimming data cannot specify lighting conditions other than the dimming value, such as the stepwise dimming time to reach the target dimming value.

The present disclosure has been made to solve the above-mentioned problems, and aims to provide a lighting device and lighting fixture that allows the sender of the dimming value to specify lighting conditions other than the dimming value.

The lighting device according to the first disclosure includes a lighting circuit that lights a light source, and a control circuit that controls the lighting circuit so that the lighting state of the light source changes to a dimming value corresponding to one of the duty ratio and frequency of a PWM signal input from the outside by a fade time corresponding to the other of the duty ratio and frequency.

The lighting device according to the second disclosure includes a lighting circuit that turns on a light source, and a control circuit that determines both a lighting condition, which is either a fade time until the light source reaches a dimming value or a color temperature of the light source, from the duty ratio of a single PWM signal input from outside, and the dimming value of the light source , and controls the lighting circuit so that the light source is turned on at the dimming value and under the lighting condition , and the fade time changes sequentially in response to changes in the duty ratio .
A lighting device according to a third disclosure includes a lighting circuit that turns on a light source, and a control circuit that determines a dimming value of the light source and a lighting condition, which is a fade time until the light source reaches the dimming value, in accordance with a duty ratio of a PWM signal input from outside, and controls the lighting circuit so that the light source is turned on at the dimming value and under the lighting condition. When the control circuit has determined the dimming value and the fade time in accordance with the duty ratio, the control circuit controls the lighting circuit so that the lighting state of the light source changes by multiplying the dimming value by the fade time, and determines the dimming value in accordance with the duty ratio when the frequency of the PWM signal is a first frequency, and determines the fade time in accordance with the duty ratio when the frequency of the PWM signal is a second frequency.
A lighting device according to a fourth disclosure includes a lighting circuit that turns on a light source, and a control circuit that determines a dimming value of the light source and a lighting condition, which is a color temperature of the light source, in accordance with a duty ratio of a PWM signal input from outside, and controls the lighting circuit so that the light source is turned on at the dimming value and the lighting condition, wherein when the control circuit has determined the dimming value and the color temperature in accordance with the duty ratio, it controls the lighting circuit so that the light source is turned on at the dimming value and the color temperature, and when the frequency of the PWM signal is a first frequency, it determines the color temperature in accordance with the duty ratio, and when the frequency of the PWM signal is a second frequency, it determines the dimming value in accordance with the duty ratio.
A lighting device according to a fifth disclosure includes a lighting circuit that turns on a light source, and a control circuit that determines a dimming value of the light source and lighting conditions, which are a fade time until the light source reaches the dimming value and a color temperature of the light source, in accordance with a duty ratio of a PWM signal input from outside, and controls the lighting circuit so that the light source is turned on at the dimming value and under the lighting conditions, wherein the control circuit determines the dimming value, the fade time, and the color temperature in accordance with the duty ratio, and controls the lighting circuit so that the light source is turned on at the dimming value, the fade time, and the color temperature.

In the lighting device according to the first disclosure, the dimming value and fade time of the light source are determined by the duty ratio and frequency of the PWM signal. Therefore, the sender of the dimming value can specify lighting conditions other than the dimming value.
In the lighting device according to the second disclosure, the dimming value of the light source and at least one of the fade time and the color temperature are determined according to the duty ratio of the PWM signal. Therefore, the sender of the dimming value can specify lighting conditions other than the dimming value.

1 is a circuit block diagram of a lighting fixture according to a first embodiment. FIG. 4 is a table showing a first correspondence relationship and a second correspondence relationship according to the first embodiment; 11 is a graph showing a change in dimming value according to a comparative example. 4 is a graph showing a change in dimming value according to the first embodiment. 13 is a table showing a first correspondence relationship and a second correspondence relationship according to a modification of the first embodiment. 13 is a table showing a correspondence relationship according to the second embodiment. 13 is a table showing a correspondence relationship according to a modification of the second embodiment. 13 is a table showing a correspondence relationship according to the third embodiment. FIG. 11 is a circuit block diagram of a lighting fixture according to a fourth embodiment. 13 is a table showing a correspondence relationship according to the fourth embodiment. 13 is a graph showing changes in dimming value and color temperature according to the fourth embodiment. 13 is a table showing a correspondence relationship according to the fifth embodiment. 13 is a graph showing changes in dimming value and color temperature according to the fifth embodiment. 23 is a table showing the correspondence relationship according to the sixth embodiment. 23 is a table showing a correspondence relationship according to the seventh embodiment.

The lighting device and lighting fixture according to each embodiment will be described with reference to the drawings. The same or corresponding components will be given the same reference numerals, and repeated description may be omitted.

Embodiment 1.
1 is a circuit block diagram of a lighting fixture 100 according to embodiment 1. The lighting fixture 100 includes a lighting device 1 and a light source module 11. The lighting device 1 includes a rectifier circuit 3, a dimming circuit 17, a lighting circuit that lights the light source module 11, and a control circuit 16 that controls the lighting circuit. The lighting circuit is made up of a step-up chopper circuit 4 and a step-down chopper circuit 5. The lighting circuit has an output terminal 21 to which the light source module 11 is connected.

The light source module 11 has a plurality of light sources 20 connected in series. The light sources 20 are light-emitting elements such as LEDs and organic EL (Electro Luminescence). The plurality of light sources 20 may be connected in parallel or in series-parallel. Furthermore, the light source module 11 may have one or more light sources 20.

The rectifier circuit 3 rectifies the AC power from the AC power source 2 into DC power. A step-up chopper circuit 4 is connected between both output terminals of the rectifier circuit 3. A step-down chopper circuit 5 is connected between both output terminals of the step-up chopper circuit 4. The step-down chopper circuit 5 supplies a constant current to the light source module 11.

In the step-down chopper circuit 5, the drain terminal of the switching element 6 is connected to the high potential side of the step-up chopper circuit 4. The source terminal of the switching element 6 is connected to the cathode terminal of the diode 8 and one end of the inductor 7. One pole of the capacitor 9 is connected to the other end of the inductor 7. The other pole of the capacitor 9 is connected to the anode terminal of the diode 8 via a resistor 10. The anode terminal of the diode 8 is connected to the low potential side output of the step-up chopper circuit 4. A light source module 11 is connected in parallel to the capacitor 9.

The resistor 10 is provided on the low-potential side output line of the step-down chopper circuit 5. The connection point between the resistor 10 and the light source module 11 is connected to the control circuit 16. The resistor 10 is an output current detection circuit that detects the current supplied by the step-down chopper circuit 5 to the light source module 11. The resistor 10 outputs an output current detection signal corresponding to the output current supplied by the step-down chopper circuit 5 to the light source module 11 to the control circuit 16. Specifically, a voltage corresponding to the lamp current flowing through the light source 20 is generated in the resistor 10. The control circuit 16 controls the step-down chopper circuit 5 based on the voltage generated in the resistor 10.

The dimming circuit 17 receives a PWM (Pulse Width Modulation) signal from a dimmer 18 included in the dimming device 19. The lighting device 1 includes an input terminal 22 to which the PWM signal is input. The PWM signal is a signal for adjusting the amount of light from the light source 20.

The control circuit 16 may be, for example, a microcomputer or a DSP (Digital Signal Processor). As an example, the control circuit 16 includes a drive circuit 12, an A/D conversion circuit 13, a processing device 14, and a storage device 15, all of which are connected to each other via an internal bus. The drive circuit 12 outputs a PWM signal that switches the switching element 6. The A/D conversion circuit 13 converts the voltage generated in the resistor 10 into a digital value.

The processor 14 receives a PWM signal from the dimming circuit 17. The processor 14 determines a target current based on the on-period or off-period of the input PWM signal. The processor 14 controls the on-off of the switching element 6 so that the lamp current detected by the resistor 10 matches the target current. The processor 14 adjusts, for example, the on-period in the switching control of the switching element 6. As a result, the control circuit 16 performs constant current control of the lighting circuit.

The storage device 15 is, for example, a non-volatile memory. The storage device 15 stores the calculation program to be executed by the processing device 14 and various data used in the calculation.

Next, the dimming control executed by the lighting device 1 according to the present embodiment will be described. The storage device 15 stores a first correspondence relationship between the duty ratio of the PWM signal and the dimming value, and a second correspondence relationship between the frequency of the PWM signal and the fade time. FIG. 2 is a table showing the first correspondence relationship and the second correspondence relationship according to the first embodiment. Here, the dimming value indicates the target dimming value of the light source 20. Furthermore, fade indicates stepwise or continuous dimming up to the target dimming value. The fade time is the time from the start of dimming until the target dimming value is reached.

The processing device 14 measures the on period and off period of the PWM signal input from the outside. The processing device 14 also measures the frequency of the PWM signal. Next, the processing device 14 reads out the fade time corresponding to the measured frequency and the dimming value corresponding to the measured duty ratio from the table stored in the memory device 15. In this way, the processing device 14 determines the dimming value and fade time from the first correspondence relationship and the second correspondence relationship.

The processing device 14 controls the lighting circuit so that the lighting state of the light source 20 changes by a dimming value corresponding to the duty ratio of the PWM signal over a fade time corresponding to the frequency. Specifically, the processing device 14 controls the switching element 6 via the drive circuit 12 so that the determined dimming value and fade time are realized.

Figure 3 is a graph showing the change in dimming value in a comparative example. Figure 3 shows the light output when the on-period or off-period of the PWM signal output by the dimmer 18 changes at regular time intervals. The processing device 14 measures the on-period or off-period of the PWM signal input from the dimming circuit 17. The storage device 15 also stores in advance a target dimming value that is determined based on the on-period or off-period. The processing device 14 performs constant current control so that the current flowing through the resistor 10 matches the target dimming value.

Figure 3 shows the change in dimming value when the fade time is not set properly. If the light output of the light source 20 reaches the target dimming value before the control circuit 16 receives the next dimming value, the light output will be stepped as shown in Figure 3. This causes light flicker.

Figure 4 is a graph showing the change in dimming value according to embodiment 1. In this embodiment, the dimming value and fade time can be set by an external PWM signal. Therefore, when dimming control is performed by changing the on-period or off-period of the PWM signal output by dimmer 18, it is possible to make the light output reach the target dimming value by taking the fade time. This allows the light output to change smoothly, and suppresses light flickering.

In the comparative example shown in FIG. 3, the dimmer 18 changes the PWM signal periodically at 10% intervals to change the dimming value in stages. In contrast, in this embodiment, once the target dimming value and fade time are notified to the control circuit 16 by the PWM signal, the light output can be changed to the target dimming value by applying the fade time. Therefore, dimming control can be easily implemented. Also, even if an arbitrary fade time is set, dimming without light flickering is possible.

In this embodiment, the sender of the PWM signal can specify lighting conditions other than the dimming value. Therefore, the sender can appropriately control the lighting state of the light source 20 using the PWM signal.

Figure 5 is a table showing the first and second correspondence relationships according to a modified example of the first embodiment. The storage device 15 stores a first correspondence relationship between the frequency of the PWM signal and the dimming value, and a second correspondence relationship between the duty ratio of the PWM signal and the fade time. In this case, the processing device 14 controls the lighting circuit so that the lighting state of the light source 20 changes by multiplying the dimming value according to the frequency of the PWM signal by the fade time according to the duty ratio. In this case, the same effect as in the first embodiment can be obtained.

In this way, the memory device 15 only needs to store a first correspondence relationship between one of the duty ratio and frequency of the PWM signal and the dimming value, and a second correspondence relationship between the other of the duty ratio and frequency of the PWM signal and the fade time.

The above table is an example of the first and second correspondence relationships, and the numerical values shown in the table are not limited. The dimming value stored in the storage device 15 as the first correspondence relationship may be a target current. The first and second correspondence relationships are not limited to tables, and may be calculation formulas for calculating the dimming value and the fade time.

These modifications can be applied as appropriate to the lighting devices and lighting fixtures according to the following embodiments. Note that the lighting devices and lighting fixtures according to the following embodiments have many things in common with embodiment 1, so the following description will focus on the differences from embodiment 1.

Embodiment 2.
In this embodiment, the table for determining the dimming value and the fade time is different from that in the first embodiment. The other configurations are the same as those in the first embodiment. The processing device 14 may determine both the dimming value and the fade time of the dimming of the light source 20 based on the duty ratio of the PWM signal. The storage device 15 in this embodiment stores the correspondence between the duty ratio of the PWM signal, the dimming value of the light source 20, and the fade time until the light source 20 reaches the dimming value. FIG. 6 is a table showing the correspondence according to the second embodiment.

Next, the dimming control executed by the lighting device 1 according to this embodiment will be described. The processing device 14 measures the on-period and off-period of the PWM signal and calculates the duty ratio. The processing device 14 reads out the dimming value and fade time corresponding to the calculated duty ratio from the table. In this way, the processing device 14 determines the dimming value and fade time of the light source 20 according to the duty ratio of the PWM signal. The processing device 14 controls the lighting circuit so that the light source 20 is turned on with the determined dimming value and fade time.

In this embodiment, as shown in FIG. 4, the light output can reach the target dimming value over the fade time. This prevents the light output from becoming stepped, and suppresses light flicker.

Figure 7 is a table showing the correspondence relationship according to a modified example of the second embodiment. The correspondence relationship between the duty ratio and the dimming value and fade time may be such that the dimming value and fade time are determined according to the duty ratio. For example, the correspondence relationship shown in Figure 7 may be used.

Embodiment 3.
In this embodiment, the table for determining the dimming value and the fade time is different from that in the second embodiment. The other configurations are the same as those in the second embodiment. The storage device 15 stores the correspondence between the duty ratio of the PWM signal, the dimming value, and the fade time. FIG. 8 is a table showing the correspondence according to the third embodiment. In the table, when the PWM signal has a first frequency, the dimming value is associated with the duty ratio, and when the PWM signal has a second frequency, the fade time is associated with the duty ratio. In the example shown in FIG. 8, the first frequency is 100 Hz, and the second frequency is 125 Hz.

The processing device 14 measures the on-period and off-period of the PWM signal and calculates the frequency and duty ratio. If the calculated frequency is the first frequency, the processing device 14 reads out the dimming value corresponding to the calculated duty ratio from the table. If the calculated frequency is the second frequency, the processing device 14 reads out the fade time corresponding to the calculated duty ratio from the table.

In this way, the processing device 14 determines the dimming value according to the duty ratio when the frequency of the PWM signal is the first frequency, and determines the fade time according to the duty ratio when the frequency of the PWM signal is the second frequency. The processing device 14 controls the lighting circuit so that the lighting state of the light source 20 changes to the target dimming value by the fade time.

In this embodiment, as shown in FIG. 4, the light output can reach the target dimming value over the fade time. This prevents the light output from becoming stepped, and suppresses light flicker.

Embodiment 4.
9 is a circuit block diagram of a lighting fixture 200 according to embodiment 4. The lighting fixture 200 includes a lighting device 201 and light source modules 11a and 11b. The lighting device 201 includes step-down chopper circuits 5a and 5b. The step-down chopper circuits 5a and 5b are connected in parallel to the output terminal of the step-up chopper circuit 4. The step-down chopper circuits 5a and 5b have the same configuration as the step-down chopper circuit 5.

Light source modules 11a and 11b are connected to the output terminals of the step-down chopper circuits 5a and 5b, respectively. The step-down chopper circuits 5a and 5b supply current to the light source modules 11a and 11b, respectively. The light source modules 11a and 11b have different color temperatures.

The control circuit 16 also has drive circuits 12a and 12b. The processing device 14 controls the step-down chopper circuit 5a via the drive circuit 12a. The processing device 14 also controls the step-down chopper circuit 5b via the drive circuit 12b. The drive circuit 12a outputs a PWM signal that switches the switching element of the step-down chopper circuit 5a. The drive circuit 12b outputs a PWM signal that switches the switching element of the step-down chopper circuit 5b. The other configurations are the same as those of the lighting device 1.

In this embodiment, the storage device 15 stores the correspondence between the duty ratio of the PWM signal, the dimming value of the light source, and the color temperature of the light source. FIG. 10 is a table showing the correspondence according to embodiment 4. Here, the dimming value corresponds to the total amount of current flowing through the light source modules 11a and 11b. Also, the color temperature corresponds to the ratio of the current flowing through the light source modules 11a and 11b. In this embodiment, the color temperature of the light source as a whole is changed by changing the ratio of the current flowing through the light source modules 11a and 11b, which have different color temperatures.

The processing device 14 reads out from the table the dimming value and color temperature corresponding to the duty ratio of the PWM signal. In this way, the processing device 14 determines the dimming value and color temperature according to the duty ratio. The processing device 14 controls the lighting circuit so that the light source modules 11a and 11b are lit at the determined dimming value and color temperature. The processing device 14 controls the total amount of current flowing to the light source modules 11a and 11b according to the dimming value, and controls the ratio of the current flowing to the light source modules 11a and 11b according to the color temperature. This controls the total amount and ratio of the light emission of the light source modules 11a and 11b.

Figure 11 is a graph showing the change in dimming value and color temperature in embodiment 4. The dimming value and color temperature of the light source change to values specified by the duty ratio of the PWM signal.

In this embodiment, the sender of the PWM signal can specify the color temperature instead of the fade time as a lighting condition other than the dimming value. Therefore, the sender can appropriately control the lighting state of the light source using the PWM signal.

The control circuit 16 may determine the dimming value of the light source and at least one of the fade time and color temperature as the lighting conditions according to the duty ratio of the PWM signal input from the outside. At this time, the memory device 15 stores the correspondence between the duty ratio of the PWM signal and the dimming value and the lighting conditions. The processing device 14 also determines the dimming value and the lighting conditions from the correspondence stored in the memory device 15.

In the present embodiment, an example in which two types of light source modules are provided as the light source has been described. However, the light source may have three or more types of light source modules. In this case, too, the total amount and ratio of light emission of the multiple light source modules are controlled so that the light source is turned on with a dimming value and color temperature determined according to the duty ratio.

Embodiment 5.
This embodiment differs from the fourth embodiment in that the control circuit 16 determines the dimming value, fade time, and color temperature according to the duty ratio of the PWM signal. The other configurations are the same as those of the fourth embodiment. The storage device 15 stores the correspondence relationships between the duty ratio, the dimming value, the fade time, and the color temperature. Fig. 12 is a table showing the correspondence relationships according to the fifth embodiment.

The processing device 14 reads out the dimming value, color temperature, and fade time of the light source corresponding to the duty ratio calculated from the PWM signal from a table stored in the storage device 15. The processing device 14 controls the lighting circuit so that the light source is turned on with the read dimming value, fade time, and color temperature.

Figure 13 is a graph showing the change in dimming value and color temperature in embodiment 5. The light output reaches the target dimming value and target color temperature after the fade time. At this time, the total amount and ratio of the light emission of light source modules 11a and 11b are controlled. In this embodiment, the light output can be prevented from becoming stepped, and light flickering can be suppressed.

Embodiment 6.
In this embodiment, the table for determining the dimming value and the color temperature is different from that in the fourth embodiment. The other configurations are the same as those in the fourth embodiment. The storage device 15 stores the correspondence between the duty ratio of the PWM signal and the dimming value and color temperature of the light source. FIG. 14 is a table showing the correspondence according to the sixth embodiment. In the table, when the PWM signal has a first frequency, the duty ratio is associated with the color temperature, and when the PWM signal has a second frequency, the dimming value is associated with the duty ratio.

When the frequency calculated from the PWM signal is a first frequency, the processing device 14 reads out the color temperature corresponding to the duty ratio from the table. When the frequency calculated from the PWM signal is a second frequency, the processing device 14 reads out the dimming value corresponding to the duty ratio from the table.

In this way, the processing device 14 determines the color temperature according to the duty ratio when the frequency of the PWM signal is the first frequency, and determines the dimming value according to the duty ratio when the frequency of the PWM signal is the second frequency. The processing device 14 controls the lighting circuit so that the light source is turned on at the determined dimming value and color temperature.

As a result, as shown in Figure 11, the dimming value and color temperature change to values specified by the duty ratio of the PWM signal.

Embodiment 7.
In this embodiment, the control circuit 16 determines the dimming value, fade time, and color temperature according to the duty ratio of the PWM signal, which is different from the sixth embodiment. The other configurations are the same as those of the sixth embodiment. The storage device 15 stores the correspondence between the duty ratio of the PWM signal and the dimming value, color temperature, and fade time of the light source. FIG. 15 is a table showing the correspondences according to the seventh embodiment. In the table, when the PWM signal has a first frequency, the color temperature is associated with the duty ratio, when the PWM signal has a second frequency, the dimming value is associated with the duty ratio, and when the PWM signal has a third frequency, the fade time is associated with the duty ratio.

When the frequency calculated from the PWM signal is a first frequency, the processing device 14 reads out the color temperature corresponding to the duty ratio from the table. When the calculated frequency is a second frequency, the processing device 14 reads out the dimming value corresponding to the duty ratio from the table. When the calculated frequency is a third frequency, the processing device 14 reads out the fade time corresponding to the duty ratio from the table.

In this way, the processing device 14 determines the color temperature according to the duty ratio when the frequency of the PWM signal is the first frequency. Also, the processing device 14 determines the dimming value according to the duty ratio when the frequency of the PWM signal is the second frequency. Furthermore, the processing device 14 determines the fade time according to the duty ratio when the frequency of the PWM signal is the third frequency. The processing device 14 controls the lighting circuit so that the light source is turned on with the determined dimming value, color temperature, and fade time.

As a result, as shown in FIG. 13, the light output takes the fade time to reach the target dimming value and the target color temperature. This prevents the light output from becoming stepped, and suppresses light flickering. In this embodiment, light flickering can be suppressed regardless of the fade time value.

The technical features described in each embodiment may be used in any suitable combination.

1 Lighting device, 2 AC power source, 3 Rectifier circuit, 4 Boost chopper circuit, 5, 5a, 5b Buck chopper circuit, 6 Switching element, 7 Inductor, 8 Diode, 9 Capacitor, 10 Resistor, 11, 11a, 11b Light source module, 12, 12a, 12b Drive circuit, 13 A/D conversion circuit, 14 Processing device, 15 Storage device, 16 Control circuit, 17 Dimming circuit, 18 Dimmer, 19 Dimming device, 20 Light source, 21 Output terminal, 22 Input terminal, 100, 200 Lighting fixture, 201 Lighting device

Claims (12)

A lighting circuit for lighting the light source;
a control circuit that controls the lighting circuit so that the lighting state of the light source changes by multiplying a dimming value corresponding to one of a duty ratio and a frequency of a PWM signal input from an external source by a fade time corresponding to the other of the duty ratio and the frequency;
A lighting device comprising: The control circuit includes:
a storage unit configured to store a first correspondence relationship between one of the duty ratio and the frequency and the dimming value, and a second correspondence relationship between the other of the duty ratio and the frequency and the fade time;
a processor that determines the dimming value and the fade time from the first correspondence relationship and the second correspondence relationship;
The lighting device according to claim 1 , further comprising: A lighting circuit for lighting the light source;
a control circuit that determines both a lighting condition, which is one of a fade time until the light source reaches a dimming value or a color temperature of the light source, from a duty ratio of a single PWM signal input from outside, and the dimming value of the light source, and controls the lighting circuit so that the light source is lit at the dimming value and under the lighting condition;
Equipped with
A lighting device, characterized in that the fade time changes sequentially in response to a change in the duty ratio . The control circuit includes:
a storage unit that stores a correspondence relationship between the duty ratio, the dimming value, and the lighting condition;
a processing unit that determines the dimming value and the lighting condition based on the correspondence relationship;
The lighting device according to claim 3 , further comprising: The lighting device according to claim 3 or 4, characterized in that the control circuit determines the dimming value and the fade time according to the duty ratio, and controls the lighting circuit so that the lighting state of the light source changes by multiplying the dimming value by the fade time. A lighting circuit for lighting the light source;
a control circuit that determines a dimming value of the light source and a lighting condition, which is a fade time until the light source reaches the dimming value, according to a duty ratio of a PWM signal input from outside, and controls the lighting circuit so that the light source is lit at the dimming value and under the lighting condition;
Equipped with
The control circuit includes:
controlling the lighting circuit so that, when the dimming value and the fade time are determined according to the duty ratio, the lighting state of the light source changes by multiplying the dimming value by the fade time;
A lighting device characterized in that, when the frequency of the PWM signal is a first frequency, the dimming value is determined in accordance with the duty ratio, and, when the frequency of the PWM signal is a second frequency, the fade time is determined in accordance with the duty ratio. The lighting device according to claim 3 or 4, characterized in that the control circuit determines the dimming value and the color temperature according to the duty ratio, and controls the lighting circuit so that the light source is turned on at the dimming value and the color temperature. A lighting circuit for lighting the light source;
a control circuit that determines a dimming value of the light source and a lighting condition, which is a color temperature of the light source, according to a duty ratio of a PWM signal input from an external device, and controls the lighting circuit so that the light source is lit at the dimming value and under the lighting condition;
Equipped with
The control circuit includes:
When the dimming value and the color temperature are determined according to the duty ratio, the lighting circuit is controlled so that the light source is turned on at the dimming value and the color temperature;
A lighting device characterized in that, when the frequency of the PWM signal is a first frequency, the color temperature is determined in accordance with the duty ratio, and, when the frequency of the PWM signal is a second frequency, the dimming value is determined in accordance with the duty ratio. A lighting circuit for lighting the light source;
a control circuit that determines a dimming value of the light source and a lighting condition, which is a fade time until the light source reaches the dimming value and a color temperature of the light source, according to a duty ratio of a PWM signal input from an external device, and controls the lighting circuit so that the light source is lit at the dimming value and under the lighting condition;
Equipped with
The control circuit determines the dimming value, the fade time, and the color temperature in accordance with the duty ratio, and controls the lighting circuit so that the light source is lit at the dimming value, the fade time, and the color temperature. The lighting device according to claim 9, characterized in that the control circuit determines the color temperature according to the duty ratio when the frequency of the PWM signal is a first frequency, determines the dimming value according to the duty ratio when the frequency of the PWM signal is a second frequency, and determines the fade time according to the duty ratio when the frequency of the PWM signal is a third frequency. The light source includes a first light source and a second light source having different color temperatures,
The lighting device according to any one of claims 7 to 10, characterized in that the control circuit controls a total amount of current flowing to the light source in accordance with the dimming value determined in accordance with the duty ratio, and controls a ratio of current flowing to the first light source and the second light source in accordance with the color temperature determined in accordance with the duty ratio. A lighting device according to any one of claims 1 to 11,
The light source;
A lighting fixture comprising:

Images