Illumination control device, illumination tool, illumination control method, and program

Abstract

To provide an illumination control device capable of turning off an illumination light during a control of a lighting control ratio of an illumination light.SOLUTION: An illumination control device 3 comprises: a signal processing part 34; and control parts 35A and 35B. The signal processing part 34 generates a plurality of control signals that controls a current flowing in light sources 2A and 2B. The control parts 35A and 35B output a current in accordance with a control value designated by each control signal to the light sources 2A and 2B. In the control parts 35A and 35B, a lower limit value in regard to a control value of the control signal is set. The control parts 35A and 35B stop an output of the current to the light sources 2A and 2B in the case where the control value of the control signal is the lower limit value or less. The signal processing part 34 changes at least one control value of the plurality of control signals to the lower limit value or more when the control value is lower than the lower limit value in all of the plurality of control signals to be generated. The signal processing part 34 outputs the control signal of which the control value is not changed to the lower limit value or larger, and the control value is not changed to the control parts 35A and 35B.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure generally relates to a lighting control device, a lighting fixture, a lighting control method, and a program, and more specifically, to a lighting control device that controls illumination light including a plurality of lights having different light colors, a lighting fixture including the lighting control device, a lighting control method, and a program. [Background technology]

[0002] The lighting device described in Patent Document 1 controls the lighting state of two light sources based on a dimming signal and a color-adjusting signal obtained from a dimmer, thereby controlling illumination light consisting of light emitted from the two light sources. The lighting device includes a microcomputer, two control ICs, and two DC / DC converters. The microcomputer outputs two PWM signals based on the dimming signal and the color-adjusting signal obtained from the dimmer. The control ICs of the two systems control the DC / DC converters of the same system based on the duty ratio specified by the PWM signal of the same system. The DC / DC converters of the two systems output currents to the light sources of the same system based on the duty ratio from the control IC of the same system. In this lighting device, the color temperature of the illumination light is controlled by controlling the color-adjusting signal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-163852 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the lighting device described in Patent Document 1, the two control ICs are configured to stop outputting current when a PWM signal with a duty ratio equal to or lower than the dimming lower limit is input. Therefore, when controlling the color temperature (dimming ratio) of the illumination light under a low dimming rate, if the duty ratios of both PWM signals of the two systems become equal to or lower than the dimming lower limit, the current flowing to the light sources of all systems may be stopped, and the illumination light may be turned off.

[0005] An object of the present disclosure is to provide a lighting control device that can prevent lighting light from being turned off when controlling the dimming ratio of lighting light (i.e., the dimming ratio of multiple light sources), a lighting fixture equipped with the lighting control device, a lighting control method, and a program. [Means for solving the problem]

[0006] A lighting control device according to an aspect of the present disclosure controls illumination light including a plurality of lights emitted from a plurality of light sources and having different light colors. The lighting control device includes a signal processor and a plurality of controllers. The signal processor corresponds to the plurality of light sources, and generates a plurality of control signals for controlling a current flowing through the corresponding light sources based on an instruction signal indicating a dimming rate of the illumination light and a dimming ratio of the plurality of light sources. The plurality of controllers correspond to the plurality of light sources and the plurality of control signals, and output a current according to a control value designated by the corresponding control signal to the corresponding light source. A lower limit value for the control value of the corresponding control signal is set in each of the plurality of controllers. When the control value of the corresponding control signal is equal to or less than the lower limit value, each of the plurality of controllers stops outputting the current to the corresponding light source. When the control value of all of the plurality of control signals generated is below the lower limit value, the signal processor changes the control value of at least one of the plurality of control signals to a value equal to or greater than the lower limit value. The signal processing unit outputs the control signal in which the control value has been changed to a value equal to or greater than the lower limit value, and the control signal in which the control value has not been changed, to a corresponding control unit among the multiple control units.

[0007] A lighting device according to one aspect of the present disclosure includes the plurality of light sources and the lighting control device according to any one of the first to fourth aspects.

[0008] A lighting control method according to an aspect of the present disclosure controls illumination light including a plurality of lights emitted from a plurality of light sources and having different light colors. The lighting control method includes a signal processing step and a control step. In the signal processing step, a plurality of control signals are generated corresponding to the plurality of light sources, based on an instruction signal indicating a dimming rate of the illumination light and a dimming ratio of the plurality of light sources, for controlling a current flowing through the corresponding light sources. In the control step, a plurality of control units corresponding to the plurality of light sources and the plurality of control signals output a current corresponding to a control value designated by the corresponding control signal to the corresponding light source. A lower limit value for the control value of the corresponding control signal is set in each of the plurality of control units. When the control value designated by the corresponding control signal is equal to or less than the lower limit value, each of the plurality of control units stops outputting the current to the corresponding light source. In the signal processing step, when the control value is below the lower limit value in all of the plurality of generated control signals, the control value in at least one control signal among the plurality of control signals is changed to a value equal to or greater than the lower limit value. In the signal processing process, the control signal in which the control value has been changed to a value equal to or greater than the lower limit value, and the control signal in which the control value has not been changed are output to corresponding control units among the multiple control units.

[0009] A program according to an embodiment of the present disclosure causes one or more processors to execute the above lighting control method. Effect of the Invention

[0010] Advantageous Effects of Invention The lighting control device, lighting device, lighting control method, and program according to one aspect of the present disclosure have the advantage that it is possible to prevent the illumination light from being turned off when the dimming level of the illumination light is being controlled. [Brief description of the drawings]

[0011] [Figure 1]FIG. 1 is a block diagram of a lighting fixture and a lighting control device according to the first embodiment. [Diagram 2] FIG. 2 is a flowchart illustrating the operation of the lighting control device. [Diagram 3] FIG. 3 is an explanatory diagram illustrating an example of time-dependent changes in control values ​​of a plurality of control signals and individual dimming rates of a plurality of light sources in a lighting control device according to the second embodiment. [Figure 4] FIG. 4 is an explanatory diagram illustrating an example of time-dependent changes in control values ​​of a plurality of control signals and individual dimming rates of a plurality of light sources in a lighting control device of Comparative Example 2. In FIG. [Diagram 5] FIG. 5 is an explanatory diagram illustrating an example of time-dependent changes in control values ​​of a plurality of control signals and individual dimming rates of a plurality of light sources in a lighting control device according to the third embodiment. [Figure 6] FIG. 6 is an explanatory diagram illustrating an example of time changes in control values ​​of a plurality of control signals and individual dimming rates of a plurality of light sources in a lighting control device according to the fourth embodiment. [Figure 7] FIG. 7 is a block diagram of a lighting device and a lighting control device according to the fifth embodiment. [Figure 8] FIG. 8 is an explanatory diagram illustrating an example of time changes in control values ​​of a plurality of control signals and individual dimming rates of a plurality of light sources in the lighting control device according to the above embodiment. [Figure 9] FIG. 9 is an explanatory diagram illustrating an example of time changes in control values ​​of a plurality of control signals and individual dimming rates of a plurality of light sources in a lighting control device of Comparative Example 3. [Figure 10] FIG. 10 is an explanatory diagram illustrating an example of time-dependent changes in control values ​​of a plurality of control signals and individual dimming rates of a plurality of light sources in a lighting control device according to embodiment 6. In FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a lighting control device and a lighting device according to an embodiment will be described with reference to the drawings. The configurations described in the following embodiments are merely examples of the present disclosure. The present disclosure is not limited to the following embodiments, and various modifications are possible depending on the design, etc., as long as the effects of the present disclosure can be achieved.

[0013] (Embodiment 1) (1) Overview An overview of a lighting control device 3 according to a first embodiment will be described with reference to FIG.

[0014] The lighting control device 3 according to the first embodiment is, for example, an architectural lighting device embedded in at least a part of a ceiling, wall, and floor as part of a building to create a space with a gradation of light. The building may be, for example, a residence such as a detached house or an apartment complex, or a non-residential building such as an office, a store, a factory, a hospital, or a warehouse.

[0015] As shown in FIG. 1, the lighting control device 3 according to the first embodiment controls illumination light including a plurality of lights having different light colors emitted from a plurality of (two in the example of FIG. 1) light sources 2A, 2B. The lighting control device 3 includes a signal processor 34 and a plurality of (two in the example of FIG. 1) control units 35A, 35B. The signal processor 34 corresponds to the plurality of light sources 2A, 2B, and generates a plurality of control signals for controlling a current flowing through the corresponding light sources 2A, 2B based on an instruction signal indicating the dimming rate of the illumination light and the dimming ratio of the plurality of light sources 2A, 2B. The plurality of control units 35A, 35B correspond to the plurality of light sources 2A, 2B and the plurality of control signals, and output a current according to a control value designated by the corresponding control signal to the corresponding light source 2A, 2B. A lower limit value for the control value of the corresponding control signal is set in each of the plurality of control units 35A, 35B. Each of the multiple control units 35A, 35B stops outputting current to the corresponding light source 2A, 2B when the control value specified in the corresponding control signal is equal to or lower than the lower limit. When the control values ​​in all of the generated multiple control signals are below the lower limit, the signal processing unit 34 changes the control value in at least one of the multiple control signals to a value equal to or higher than the lower limit. The signal processing unit 34 outputs the control signal whose control value has been changed to a value equal to or higher than the lower limit and the control signal whose control value has not been changed to the corresponding control unit of the multiple control units 35A, 35B.

[0016] According to this configuration, when the control value falls below the lower limit in all of the generated control signals, the control value in at least one of the multiple control signals is changed to a value equal to or greater than the lower limit. Therefore, when the control value falls below the lower limit in all of the generated control signals, it is possible to prevent all of the multiple light sources 2A, 2B from being turned off. This makes it possible to prevent the illumination light from being turned off by turning off all of the light sources 2A, 2B when controlling the dimming ratio (e.g., color temperature) of the illumination light under a low dimming rate.

[0017] (2) Details The configurations of a lighting control device and a lighting fixture according to a first embodiment will be described with reference to FIG.

[0018] The lighting device 1 according to the first embodiment emits illumination light including a plurality of (e.g., two) lights having different light colors. As shown in Fig. 1, the lighting device 1 includes a plurality of (two in the example of Fig. 1) light sources 2A and 2B and a lighting control device 3.

[0019] (2.1) Multiple Light Sources The multiple light sources 2A, 2B emit (i.e., radiate) light of different colors. The light source 2A emits light of, for example, a color (color temperature) of 2700K. The light source 2B emits light of, for example, a color (color temperature) of 6500K. Each of the multiple light sources 2A, 2B has one or more light-emitting elements. Each of the one or more light-emitting elements is, for example, an LED (Light-Emitting Diode). The one or more light-emitting elements are, for example, connected to each other in series.

[0020] (2.2) Lighting control device As shown in FIG. 1, the lighting control device 3 controls the dimming rate of the illumination light consisting of the light emitted from the light sources 2A, 2B and the dimming ratio of the light sources 2A, 2B (hereinafter simply referred to as "dimming rate"). The dimming rate indicates the ratio of the individual dimming rates of the light sources 2A, 2B. If any one of the color temperature, chromaticity coordinates, and color palette of the illumination light is specified, it is possible to specify the individual dimming rate of the light sources 2A, 2B from the specified information. For this reason, the dimming rate may be, for example, content indicating the color temperature, chromaticity coordinates, or color palette of the illumination light.

[0021] More specifically, the lighting control device 3 includes a rectifier circuit 31, a boost converter 32, a dimmer 33, a signal processing unit 34, and a plurality of control units 35A, 35B.

[0022] (2.2.1) Matching circuit The rectifier circuit 31 converts an AC voltage supplied from an external AC power source 4 (e.g., a commercial power source) into a DC voltage by rectifying (e.g., full-wave rectification) and outputs the converted DC voltage to the boost converter 32. The rectifier circuit 31 includes, for example, a diode bridge circuit that rectifies the AC voltage into a DC voltage, and a smoothing capacitor that smoothes the output voltage of the diode bridge circuit.

[0023] (2.2.2) Boost converter The boost converter 32 boosts the output voltage of the rectifier circuit 31 to a required voltage and outputs the boosted voltage to the multiple control units 35A, 35B. The boost converter 32 outputs the same voltage to the multiple control units 35A, 35B. The boost converter 32 includes, for example, an inductor, a switching element, a diode, and a control IC. The boost converter 32 boosts the output voltage of the rectifier circuit 31 to a required voltage by alternately switching the switching elements on and off by the control IC.

[0024] (2.2.3) Dimmer Dimmer 33 outputs an instruction signal instructing the dimming rate and dimming ratio of the illumination light of lighting fixture 1 to signal processor 34. Dimmer 33 receives, for example, an operation (instruction operation) from a user instructing the dimming rate and dimming ratio of the illumination light of lighting fixture 1, and outputs the instruction signal to signal processor 34 based on the received operation.

[0025] (2.2.4) Signal Processing Section The signal processing unit 34 is composed of, for example, a microcomputer. More specifically, the signal processing unit 34 is a computer system mainly composed of a processor and a memory. The computer system executes a program stored in the memory to realize the function of the signal processing unit 34. The program may be pre-recorded in the memory, may be provided via a telecommunication line such as the Internet, or may be provided by recording it on a recording medium such as a memory card.

[0026] The signal processor 34 generates a plurality of control signals based on the instruction signal from the dimmer 33. The plurality of control signals correspond one-to-one to the plurality of light sources 2A, 2B, and are signals for controlling the current flowing through the corresponding light sources. Since the brightness (individual dimming rate) of the light sources 2A, 2B is controlled by controlling the current flowing through the light sources 2A, 2B, the plurality of control signals are also signals for controlling the brightness of the corresponding light source 2A or 2B.

[0027] More specifically, the multiple control signals are signals that specify control values, and the specified control values ​​specify the values ​​of currents flowing through the corresponding light sources 2A or 2B. Specifically, the multiple control signals are, for example, PWM (Pulse Width Modulation) signals, and the duty ratio (control value) of the PWM signals specifies the values ​​of currents flowing through the corresponding light sources.

[0028] A lower limit is set for each of the control values ​​of the plurality of control signals, as described later. When a control signal having a control value equal to or less than the lower limit is input, the control units 35A and 35B stop outputting a current to the corresponding light source 2A or 2B, as described later. In other words, the lower limit is the lower limit of the control value when the control units 35A and 35B output a current corresponding to the control value of the input control signal to the corresponding light source 2A or 2B.

[0029] When the control values ​​of all the generated control signals are below the lower limit, the signal processing unit 34 changes the control value of at least one of the control signals to a value equal to or greater than the lower limit, and does not change the control values ​​of the remaining control signals. The control signals correspond one-to-one to the control units 35A, 35B. As described above, the signal processing unit 34 outputs the control signal whose control value has been changed to a value equal to or greater than the lower limit and the control signal whose control value has not been changed to the corresponding control unit of the control units 35A, 35B.

[0030] (2.2.5) Multiple Control Units The multiple control units 35A, 35B correspond one-to-one to the multiple control signals output from the signal processing unit 34, and output a current according to a control value specified by the corresponding control signal to a corresponding one of the multiple light sources 2A, 2B.

[0031] It is assumed that the multiple control units 35A, 35B correspond one-to-one to the multiple light sources 2A, 2B. This correspondence is self-evident because, as described above, the multiple control units 35A, 35B correspond one-to-one to the multiple control signals, and the multiple control signals correspond one-to-one to the multiple light sources 2A, 2B.

[0032] More specifically, the multiple control units 35A, 35B transform (e.g., step down) the output voltage of the boost converter 32 to a predetermined voltage. The predetermined voltage is a voltage corresponding to a current specified by a control value of a corresponding control signal among the multiple control signals output from the signal processing unit 34. Through the transformation, the multiple control units 35A, 35B control the output current of the boost converter 32 to match the current specified by the control value, and output the controlled output current to the corresponding light source among the multiple light sources 2A, 2B.

[0033] More specifically, the multiple control units 35A and 35B each include a control circuit 351A, 351B and a step-down converter 352A, 352B.

[0034] The control circuit 351A corresponds to the step-down converter 352A. The control circuit 351A controls the corresponding step-down converter 352A based on a corresponding control signal. The step-down converter 352A converts the output voltage of the step-up converter 32 to a predetermined voltage based on the control from the control circuit 351A. More specifically, the step-down converter 352A includes, for example, an inductor, a switching element, a diode, and the like. The control circuit 351A PWM controls the on-off switching of the switching element based on the control value (duty ratio) of the corresponding control signal. That is, the control circuit 351A periodically switches the switching element on and off, and controls the on-off switching of the switching element so that the ratio of the on time to the off time in each period becomes the ratio specified by the duty ratio.

[0035] Similarly, the control circuit 351B corresponds to the corresponding step-down converter 352B. The control circuit 351B controls the corresponding step-down converter 352B based on the corresponding control signal. The step-down converter 352B converts the output voltage of the step-up converter 32 to the above-mentioned predetermined voltage based on the control from the control circuit 351B. More specifically, the step-down converter 352B includes, for example, an inductor, a switching element, a diode, and the like. The control circuit 351B PWM controls the on-off switching of the switching element based on the control value (duty ratio) of the corresponding control signal. That is, the control circuit 351B periodically switches the switching element on and off, and controls the on-off switching of the switching element so that the ratio of the on time to the off time in each period becomes the ratio specified by the duty ratio.

[0036] (2.3) Characteristics of the control unit The control circuits 351A and 351B are configured by IC chips (Integrated Circuits). A lower limit value for the control value of the corresponding control signal is set in the control circuits 351A and 351B. The lower limit values ​​set in the plurality of control circuits 351A and 351B include, for example, values ​​different from each other. In the first embodiment, the lower limit values ​​set in the plurality of control circuits 351A and 351B are, for example, values ​​different from each other.

[0037] The control units 35A and 35B control the currents to be output to the corresponding light sources 2A and 2B in response to the control value of the control signal from the signal processing unit 34. At this time, the control units 35A and 35B have a characteristic of stopping the output of the currents to the corresponding light sources 2A and 2B when the control value is equal to or less than the lower limit value. That is, the control circuits 351A and 351B control the output voltages of the corresponding step-down converters 352A and 352B in response to the control value of the control signal from the signal processing unit 34. At this time, the control circuits 351A and 351B have a characteristic of controlling the step-down converters 352A and 352B so as to stop the output voltages of the corresponding step-down converters 352A and 352B in response to the control value of the control signal from the signal processing unit 34 when the control value of the corresponding control signal is equal to or less than the lower limit value.

[0038] (3) Operation of lighting control device 2, the operation of the lighting control device 3 will be described when the dimming rate of the illumination light instructed by the instruction signal from the dimmer 33 is, for example, a low dimming rate. The low dimming rate is a relatively low dimming rate (for example, a dimming rate of 1% or less) and is a dimming rate greater than 0%.

[0039] When the signal processor 34 acquires an instruction signal from the dimmer 33 (step S1), the signal processor 34 generates a plurality of (e.g., two) control signals corresponding one-to-one to a plurality of (e.g., two) control units 35A, 35B based on the acquired instruction signal (step S2). Then, when the signal processor 34 generates a plurality of control signals, it judges whether or not the control values ​​of the control signals are below the lower limit value in all of the generated plurality of control signals (step S3). If the result of the judgment is that the control values ​​of all the control signals are below the lower limit value (Yes in step S3), the signal processor 34 changes the control value of at least one of the generated plurality of control signals to a value equal to or higher than the lower limit value (e.g., the lower limit value), and does not change the control values ​​of the remaining control signals (step S4). Then, the process proceeds to step S6. On the other hand, if the result of the judgment in step S3 is that the control values ​​of all the control signals are not below the lower limit value (No in step S3), the signal processor 34 does not change the control values ​​in all of the generated plurality of control signals (step S5). Then, the process proceeds to step S6.

[0040] In step S6, the signal processing unit 34 outputs the above-mentioned multiple control signals to the corresponding multiple control units 35A, 35B. That is, the signal processing unit 34 outputs a control signal corresponding to the control unit 35A to the control unit 35A, and outputs a control signal corresponding to the control unit 35B to the control unit 35B. More specifically, when the process proceeds from Yes in step S3 to step S6, the signal processing unit 34 outputs the control signal whose control value has been changed to a value equal to or greater than the lower limit value as described above, and the control signal whose control value has not been changed, to the corresponding control units 35A, 35B. Also, when the process proceeds from No in step S3 to step S6, the signal processing unit 34 outputs the control signal whose control value has not been changed (i.e., the generated multiple control signals) to the corresponding control unit among the multiple control units 35A, 35B. Then, the multiple control units 35A, 35B output the current designated by the control value of the corresponding control signal to the corresponding light sources 2A, 2B (step S7). More specifically, the control unit 35A outputs a current designated by the control value of the control signal corresponding to the control unit 35A to the light source 2A corresponding to the control signal. The control unit 35B outputs a current designated by the control value of the control signal corresponding to the control unit 35B to the light source 2B corresponding to the control signal. This causes the multiple light sources 2A and 2B to emit light at brightness (individual dimming rate) according to the control value of the corresponding control signal. Then, the process returns to step S1.

[0041] In this way, in the lighting control device 3, when the control values ​​of all the control signals fall below the lower limit, the signal processor 34 changes the control value of at least one of the generated control signals to a value equal to or higher than the lower limit (e.g., the lower limit). Therefore, when the dimming rate of the illumination light is a low dimming rate, it is possible to prevent all the light sources from being turned off when the control values ​​of all the generated control signals fall below the lower limit.

[0042] (4) Comparative Example As Comparative Example 1, in the lighting control device 3 of the first embodiment, when the dimming rate of the illumination light is, for example, a low dimming rate, the signal processing unit 34 does not change the control values ​​of all the generated control signals when the control values ​​of all the generated control signals are below the lower limit (i.e., when the answer is Yes in step S3). In this case, since the control values ​​of all the control signals are below the lower limit, all the control units 35A, 35B stop the currents output to the corresponding light sources 2A, 2B due to the characteristics of the control units 35A, 35B described above. As a result, in Comparative Example 1, when the dimming rate of the illumination light is a low dimming rate and the control values ​​of all the control signals are below the lower limit, all the light sources 2A, 2B are turned off and the illumination light is turned off. In other words, when the dimming rate of the illumination light is a low dimming rate, the illumination light is turned off even though it should not be turned off, and the user feels uncomfortable.

[0043] In contrast, in the lighting control device 3 of the first embodiment, as described above, when the control values ​​of all the control signals fall below the lower limit (i.e., when the answer is Yes in step S3), the signal processor 34 changes the control value of at least one of the generated control signals to a value equal to or greater than the lower limit (e.g., the lower limit). Therefore, when the dimming rate of the illumination light is a low dimming rate, it is possible to prevent all the light sources from being turned off when the control values ​​of all the generated control signals fall below the lower limit.

[0044] (5) Effects As described above, the lighting control device 3 according to the first embodiment controls illumination light including a plurality of lights having different light colors emitted from a plurality of light sources 2A, 2B. The lighting control device 3 includes a signal processor 34 and a plurality of controllers 35A, 35B. The signal processor 34 corresponds to the plurality of light sources 2A, 2B, and generates a plurality of control signals for controlling a current flowing through the corresponding light sources 2A, 2B based on an instruction signal indicating the dimming rate of the illumination light and the dimming ratio of the plurality of light sources 2A, 2B. The plurality of controllers 35A, 35B correspond to the plurality of light sources 2A, 2B and the plurality of control signals, and output a current according to a control value designated by the corresponding control signal to the corresponding light sources 2A, 2B. A lower limit value for the control value of the corresponding control signal is set in each of the plurality of controllers 35A, 35B. When the control value of the corresponding control signal is equal to or lower than the lower limit value, each of the plurality of controllers 35A, 35B stops outputting a current to the corresponding light source 2A, 2B. When the control values ​​of all the generated control signals are below the lower limit, the signal processing unit 34 changes the control value of at least one of the control signals to a value equal to or greater than the lower limit. The signal processing unit 34 outputs the control signal whose control value has been changed to a value equal to or greater than the lower limit and the control signal whose control value has not been changed to a corresponding one of the multiple control units.

[0045] According to this configuration, when the control value falls below the lower limit in all of the generated control signals, the control value in at least one of the multiple control signals is changed to a value equal to or greater than the lower limit. Therefore, when the control value falls below the lower limit in all of the generated control signals, it is possible to prevent all of the multiple light sources from being turned off. This makes it possible to prevent the illumination light from being turned off by turning off all of the light sources when controlling the dimming ratio of the illumination light under a low dimming rate, for example.

[0046] In addition, in the lighting control device 3, the lower limit values ​​set in the multiple control units 35A, 35B include values ​​that are different from each other. With this configuration, the lower limit values ​​set in the control values ​​of the multiple control signals can be made different from each other. This makes it possible to set the lower limit values ​​to optimal values ​​according to the control units 35A, 35B.

[0047] Furthermore, lighting fixture 1 includes multiple light sources 2A, 2B and lighting control device 3. With this configuration, lighting fixture 1 that provides the effects of lighting control device 3 can be provided.

[0048] (6) Aspects other than lighting control devices Functions similar to those of the lighting control device 3 of embodiment 1 may be embodied in a lighting control method, a program for causing one or more processors to execute this lighting control method, a non-transitory recording medium on which this program is recorded, etc.

[0049] The illumination control method controls illumination light including a plurality of lights emitted from a plurality of light sources and having different light colors. The illumination control method includes a signal processing step and a control step. In the signal processing step, a plurality of control signals are generated corresponding to the plurality of light sources, and based on an instruction signal instructing a dimming rate of the illumination light and a dimming ratio of the plurality of light sources, for controlling a current flowing through the corresponding light sources. In the control step, a plurality of control units corresponding to the plurality of light sources and the plurality of control signals output a current corresponding to a control value designated by the corresponding control signal to the corresponding light source. A lower limit value for the control value of the corresponding control signal is set in each of the plurality of control units. When the control value designated by the corresponding control signal is equal to or less than the lower limit value, each of the plurality of control units stops outputting a current to the corresponding light source. In the signal processing step, when the control value is less than the lower limit value in all of the plurality of generated control signals, the control value of at least one of the plurality of control signals is changed to a value equal to or more than the lower limit value. In the signal processing step, a control signal in which the control value has been changed to the value equal to or more than the lower limit value and a control signal in which the control value has not been changed are output to a corresponding control unit of the plurality of control units.

[0050] The program causes one or more processors to execute the lighting control method.

[0051] The non-transitory recording medium records a program for causing one or more processors to execute the lighting control method.

[0052] (7) Variations A modification of the first embodiment will now be described.

[0053] (7.1) In the first embodiment, the lighting control device 3 includes two light sources 2A and 2B that emit light of different colors. However, the lighting control device 3 may include three or more light sources that emit light of different colors.

[0054] (Embodiment 2) A lighting control device 3B and a lighting device 1B according to a second embodiment will be described with reference to FIGS. 1, 3, and 4.

[0055] (1) Composition As shown in Fig. 1, lighting fixture 1B according to embodiment 2 includes lighting control device 3B according to embodiment 2 and multiple (two in the example of Fig. 1) light sources 2A, 2B. Similarly to lighting control device 3 according to embodiment 1, lighting control device 3B according to embodiment 2 includes rectifier circuit 31, boost converter 32, dimmer 33, signal processing unit 34B, and multiple control units 35A, 35B. Lighting control device 3B has the same configuration as lighting control device 3, except that signal processing unit 34B operates differently. Therefore, among the configuration of lighting control device 3B, the same configuration as the configuration of lighting control device 3 of embodiment 1 is denoted by the same reference numerals and description thereof will be omitted.

[0056] In the second embodiment, a case is illustrated in which the dimming ratio (e.g., color temperature) of the illumination light gradually changes from the light color of the light source 2A (e.g., 2700K) to the light color of the light source 2B (e.g., 6500K) when the dimming ratio of the illumination light is, for example, a low dimming ratio (e.g., 1%). In this case, the multiple (e.g., two) control signals generated by the signal processing unit 34B include a first number (one in the second embodiment) of first control signals M1 and a second number (one in the second embodiment) of second control signals N1 (see FIG. 3). The first number is at least one number, and in the second embodiment, for example, one. The second number is at least one number, and in the second embodiment, for example, one. The first control signal M1 is a signal that controls the current flowing through the light source 2A, and in the above case, has a control value m1 that indicates a decreasing tendency while the color temperature of the illumination light changes as described above. The second control signal N1 is a signal that controls the current flowing through the light source 2B, and in the above case, is a signal having a control value n1 that indicates an increasing trend while the color temperature of the illumination light changes as described above.

[0057] When the signal processor 34B acquires an instruction signal from the dimmer 33, it generates a plurality of (two in the example of FIG. 3) control signals M1, N1 based on the acquired instruction signal (see FIG. 3). Then, the signal processor 34 changes the control value m1 in at least one first control signal M1 of the first number of first control signals M1 generated to a value m2 (e.g., lower limit value T1) equal to or greater than the lower limit value T1 from when the control values ​​m1, n1 fall below the lower limit value T1 in all of the generated plurality of control signals M1, N1 until the control value n1 in at least one second control signal N1 of the first number of (one in the example of FIG. 3) second control signals N1 generated becomes equal to or greater than the lower limit value T1 (e.g., lower limit value T1). Then, the signal processor 34B outputs the first control signal M1 in which the control value m1 has been changed to a value m2 equal to or greater than the lower limit value T1 and the control signal N1 in which the control value n1 has not been changed to the corresponding control unit of the plurality of control units 35A, 35B.

[0058] In addition, in embodiment 2, the lower limit value T1 set to each of the control values ​​m1, n1 of the multiple control signals (the first number of first control signals M1 and the second number of second control signals N1) is assumed to be the same value, but may be different values.

[0059] (2) Operation Description The operation of the lighting control device 3B according to the second embodiment will be described with reference to FIG.

[0060] 3 illustrates an operation in which the dimming ratio (e.g., color temperature) of the illumination light gradually changes from the light color of the light source 2A (e.g., 2700 K) to the light color of the light source 2B (e.g., 6500 K) when the dimming ratio of the illumination light is, for example, a low dimming ratio (e.g., 1%). In this case, the multiple control signals M1 and N1 generated by the signal processing unit 34B include, as described above, the first control signal M1 having the control value m1 with a decreasing tendency and the second control signal N1 having the control value n1 with an increasing tendency.

[0061] 3, the horizontal axis indicates time, the left vertical axis indicates control values ​​m1, n1 of the multiple control signals M1, N1 generated by the signal processor 34, and the right vertical axis indicates individual dimming rates Q1, Q2 of the multiple light sources 2A, 2B. The individual dimming rate Q1 indicates the dimming rate of the light source 2A, and the individual dimming rate Q2 indicates the dimming rate of the light source 2B. The time on the horizontal axis indicates the passage of time when the color temperature of the illumination light changes.

[0062] While the color temperature of the illumination light gradually changes from the light color (2700K) of the light source 2A to the light color (6500K) of the light source 2B, the signal processor 34B acquires an instruction signal from the dimmer 33 at regular time intervals. Then, the signal processor 34B generates a plurality of control signals M1, N1 from the acquired instruction signal, and determines whether the control values ​​m1, n1 are below the lower limit value T1 in all of the generated plurality of control signals M1, N1.

[0063] In the interval where \(t_0\leq t < t_1\), among the plurality of control signals \(M1\) and \(N1\) generated by the signal processing unit \(34B\), the control value \(m1\) of the first control signal \(M1\) is greater than or equal to the lower limit value \(T1\), and the control value \(n1\) of the second control signal \(N1\) is less than the lower limit value \(T1\). That is, the control values \(m1\) and \(n2\) of all the control signals among the plurality of control signals \(M1\) and \(N1\) are not the lower limit value \(T1\). In this case, the signal processing unit \(34B\) does not change the control values \(m1\) and \(n1\) of each of the generated plurality of control signals \(M1\) and \(N1\). Therefore, the signal processing unit \(34\) outputs the generated plurality of control signals \(M1\) and \(N1\) to the corresponding control units \(35A\) and \(35B\) without changing their control values \(m1\) and \(n1\).

[0064] Then, the plurality of control units \(35A\) and \(35B\) output currents corresponding to the control values \(m1\) and \(n1\) specified by the control signals \(M1\) and \(N1\) input from the signal processing unit \(34\) to the corresponding light sources \(2A\) and \(2B\). More specifically, since the control value \(m1\) of the control signal \(M1\) input to the control unit \(35A\) is a value greater than or equal to the lower limit value \(T1\), the control unit \(35A\) outputs a current corresponding to the control value \(m1\) to the corresponding light source \(2A\). On the other hand, since the control value \(n1\) of the control signal \(N1\) input to the control unit \(35B\) is a value less than the lower limit value \(T1\), the control unit \(35B\) stops the output of the current to the corresponding light source \(2B\) according to the characteristics of the control unit \(35B\). As a result, the individual dimming rate \(Q1\) of the light source \(2A\) becomes the individual dimming rate corresponding to the control value \(m1\), and the individual dimming rate \(Q2\) of the light source \(2B\) becomes zero.

[0065] Therefore, in this interval (\(t_0\leq t < t_1\)), the illumination light becomes illumination light with a dimming rate corresponding to the control value \(m1\) and a color temperature equal to the color temperature (\(2700K\)) of the light color of the light source \(2A\).

[0066] In the section of time t where t1≦t≦t2, the control values ​​m1, n1 of all of the control signals M1, N1 generated by the signal processing unit 34B are below the lower limit value T1. In this case, the signal processing unit 34B changes the control value m1 of at least one of the first control signals M1 among the first number (one in the example of FIG. 3) generated first control signals M1 to a value m2 (lower limit value T1 in the example of FIG. 3) that is equal to or greater than the lower limit value T1, and does not change the control values ​​m1 of the remaining (zero in the example of FIG. 3) first control signals M1. That is, the signal processor 34B changes the control value m1 of at least one first control signal M1 among the first number of first control signals M1 generated to a value m2 equal to or greater than the lower limit value T1 from the time when the control values ​​m1, n1 of all the control signals M1, N1 fall below the lower limit value T1 at time t1 until the control value of at least one second control signal N1 among the second number of second control signals (one in FIG. 3) generated becomes equal to or greater than the lower limit value T1 at time t2, and does not change the control values ​​m1 of the remaining first control signals M1. Then, the signal processor outputs the control signal M1 whose control value m1 has been changed to a value m2 equal to or greater than the lower limit value T1 and the control signal N1 whose control value n1 has not been changed to the corresponding control unit among the multiple control units 35A, 35B.

[0067] More specifically, in the second embodiment, since the first number is one, the signal processor 34 changes the control value m1 of the one generated first control signal M1 to a value m2 equal to or greater than the lower limit T1, and does not change the control value n1 of the one generated second control signal N1. Then, the signal processor 34 outputs the first control signal M1 in which the control value m1 has been changed to the control value m2 to the corresponding controller 35A, and outputs the second control signal N1 in which the control value n1 is not changed to the corresponding controller 35B.

[0068] Then, the multiple control units 35A and 35B output currents according to the control values ​​m2 and n1 designated by the control signals M1 and N1 input from the signal processing unit 34B to the corresponding light sources 2A and 2B. More specifically, since the control value m2 of the control signal M1 input to the control unit 35A is equal to or greater than the lower limit value T1, the control unit 35A outputs currents according to the control value m2 to the corresponding light source 2A. On the other hand, since the control value n1 of the control signal N1 input to the control unit 35B is less than the lower limit value T1, the control unit 35B stops outputting currents to the corresponding light source 2B due to the characteristics of the control unit 35B. As a result, the individual dimming rate Q1 of the light source 2A becomes an individual dimming rate according to the control value m2, and the individual dimming rate Q2 of the light source 2B becomes zero.

[0069] Therefore, in this section (section t1≦t≦t2), the illumination light has a dimming rate according to control value m2 and a color temperature of the light color of light source 2A (2700K).

[0070] Thus, in this section (section t1≦t≦t2), the control values ​​m1, n1 of all the generated control signals M1, N1 are below the lower limit T1. Therefore, all the light sources 2A, 2B would normally stop emitting light, and the illumination light would be turned off. However, as described above, the control value m1 of at least one of the first control signals M1 among the first number of generated first control signals M1 is changed to a value m2 that is equal to or greater than the lower limit T1. Therefore, the light source 2A corresponding to the changed first control signal M1 emits light, and the turning off of all of the multiple light sources 2A, 2B is prevented.

[0071] In the interval where t2 < t ≤ t3, the control value n1 of at least one of the second number of second control signals N1 generated by the signal processing unit 34B becomes a value equal to or higher than the lower limit value T1. In Embodiment 2, since the second number is one, in this case, the control value n1 of the one second control signal N1 generated by the signal processing unit 34B becomes the lower limit value T1. In this case, the signal processing unit 34 does not change the control values m1 and n1 of each of the plurality of generated control signals M1 and N1, similar to the case of the interval t0 ≤ t < t1. Therefore, the signal processing unit 34B outputs the plurality of generated control signals M1 and N1 to the corresponding control units 35A and 35B without changing their control values m1 and n1.

[0072] Then, the plurality of control units 35A and 35B output currents corresponding to the control values m1 and n1 specified by the control signals M1 and N1 input from the signal processing unit 34B to the corresponding light sources 2A and 2B. More specifically, since the control value n1 of the control signal N1 input to the control unit 35B is a value equal to or higher than the lower limit value T1, the control unit 35B outputs a current corresponding to the control value n1 to the corresponding light source 2B. On the other hand, since the control value m1 of the control signal M1 input to the control unit 35A is a value less than the lower limit value T1, the control unit 35A stops the output of the current to the corresponding light source 2A according to the characteristics of the control unit 35A. As a result, the individual dimming rate Q1 of the light source 2A becomes zero, and the individual dimming rate Q2 of the light source 2B becomes the individual dimming rate corresponding to the control value n1.

[0073] Therefore, in this interval (the interval where t2 < t ≤ t3), the illumination light becomes illumination light with a dimming rate corresponding to the control value n1 and a color temperature equal to the color temperature (6500K) of the light color of the light source 2B.

[0074] (3) Comparative Example As Comparative Example 2, in the lighting control device 3B of Embodiment 2, when the control values m1 and n1 of all the generated control signals M1 and N1 are below the lower limit value T1 (that is, in the section where t1 ≦ t < t2), consider the case where the control values m1 and n1 of all the generated control signals M1 and N1 are not changed. In this case, as shown in FIG. 4, in the section where t1 ≦ t < t2, since the control values m1 and n1 of all the control signals M1 and N1 are below the lower limit value T1, all the control units 35A and 35B stop the current output to the corresponding light sources 2A and 2B according to the characteristics of the control units 35A and 35B. As a result, in Comparative Example 2, the section where t1 ≦ t < t2 becomes a light-off section where all the light sources 2A and 2B are turned off and the illumination light is turned off. That is, in Comparative Example 2, when the color temperature of the illumination light is gradually changed from the color temperature of the light color of the light source 2A to the color temperature of the light color of the light source 2B, in the middle section (the section where t1 ≦ t < t2), the illumination light is turned off contrary to the user's intention. Therefore, the user feels discomfort.

[0075] On the other hand, in the lighting control device 3B of Embodiment 2, as described above, when the control values m1 and n1 of all the control signals M1 and N1 are below the lower limit value T1 (that is, in the section where t1 ≦ t < 2), the signal processing unit 34B changes the control value m1 of at least one of the generated plurality of control signals M1 to a value m2 that is equal to or higher than the lower limit value T1. Therefore, when the color temperature of the illumination light is gradually changed from the color temperature of the light color (2700K) of the light source 2A to the color temperature of the light color (6500K) of the light source 2B, it is possible to prevent the illumination light from being unexpectedly turned off in the middle section (between time point t1 and time point t2). Therefore, the user does not feel discomfort. (4) Effects As described above, in the lighting control device 3B according to the second embodiment, in the first embodiment, the multiple control signals include a first number (e.g., one) of first control signals M1 having a decreasing control value m1 and a second number (e.g., one) of second control signals N1 having an increasing control value n1. The signal processing unit 34B changes the control value m1 in at least one first control signal M1 among the first number of first control signals M1 generated to a value m2 equal to or greater than the lower limit value T1 from when the control values ​​m1, n1 in all of the generated multiple control signals M1, N1 fall below the lower limit value T1 until the control value n1 in at least one second control signal N1 among the generated second number of second control signals N1 becomes equal to or greater than the lower limit value T1 (e.g., the lower limit value T1). The signal processing unit 34B outputs a first control signal M1 in which the control value m1 is changed to a value m2 greater than or equal to the lower limit value T1, a first control signal in which the control value is not changed, and a second control signal N1 in which the control value n1 is not changed to a corresponding control unit among the multiple control units 35A, 35B.

[0076] According to this configuration, by simply controlling the control value m1 of at least one of the first control signals M1 among the generated first number of first control signals M1 to a value m2 equal to or greater than the lower limit value T1, it is possible to prevent the illumination light from being turned off by turning off all of the light sources 2A, 2B when controlling the dimming ratio of the illumination light under a low dimming rate.

[0077] (Embodiment 3) A lighting control device 3C and a lighting device 1C according to a third embodiment will be described with reference to FIGS. 1 and 5.

[0078] In the lighting control device 3B of embodiment 2, the signal processing unit 34B changes the control value m1 to a value m2 that is greater than or equal to the lower limit value T1 in at least one of the first number of generated first control signals M1 from the time when the control values ​​m1, n1 fall below the lower limit value T1 in all of the generated multiple control signals M1, N1 until the control value n1 becomes greater than or equal to the lower limit value T1 in at least one of the second number of generated second control signals N1.

[0079] In contrast, in the lighting control device 3C of embodiment 3, the signal processing unit 34C changes the control value n1 in at least one second control signal N1 among the second number of second control signals N1 generated to a value n2 (e.g., lower limit value T1) that is greater than or equal to the lower limit value T1 from the time when the control values ​​m1, n1 fall below the lower limit value T1 in all of the generated multiple control signals M1, N1 until the control value n1 in at least one second control signal N1 among the second number of second control signals N1 generated becomes greater than or equal to the lower limit value T1.

[0080] As described above, lighting control device 3C according to embodiment 3 is configured similarly to lighting control device 3B according to embodiment 2, except that the operation of signal processing unit 34C is different. Therefore, among the configurations of lighting control device 3C, the same configurations as those of lighting control device 3B are denoted by the same reference numerals and description thereof will be omitted (see FIG. 1).

[0081] When the signal processor 34C of the third embodiment acquires an instruction signal from the dimmer 33, it generates a plurality of control signals M1, N1 based on the acquired instruction signal. Then, the signal processor 34C changes the control value n1 in at least one second control signal N1 of the second number of second control signals N1 generated to a value n2 (e.g., lower limit value T1) equal to or greater than the lower limit value T1 from when the control values ​​m1, n1 fall below the lower limit value T1 in all of the generated plurality of control signals M1, N1 until the control value n1 in at least one second control signal N1 of the first number of second control signals N1 generated becomes equal to or greater than the lower limit value T1 (e.g., lower limit value T1). Then, the signal processor 34 outputs the second control signal N1 in which the control value n1 has been changed to a value n2 equal to or greater than the lower limit value T1, the second control signal in which the control value has not been changed, and the first control signal M1 in which the control value m1 has not been changed to the corresponding control unit of the plurality of control units 35A, 35B.

[0082] (2) Operation Description The operation of the lighting control device 3C according to the third embodiment will be described with reference to FIG.

[0083] In the example of FIG. 5, similar to the example of FIG. 3, when the dimming rate of the illumination light is, for example, a low dimming rate (e.g., 1%), the operation when the dimming ratio (e.g., color temperature) of the illumination light gradually changes from the light color of light source 2A (e.g., 2700K) to the light color of light source 2B (e.g., 6500K) is illustrated. In this case, the plurality of control signals generated by the signal processing unit 34 includes, similar to Embodiment 2, a first control signal M1 having a control value m1 with a decreasing tendency and a second control signal N1 having a control value n1 with an increasing tendency.

[0084] In the example of FIG. 5, the horizontal axis represents time, the left vertical axis represents the control values m1 and n1 of the plurality of control signals M1 and N1 generated by the signal processing unit 34, and the right vertical axis represents the individual dimming rates Q1 and Q2 of each of the plurality of light sources 2A and 2B. The individual dimming rate Q1 represents the dimming rate of light source 2A, and the individual dimming rate Q2 represents the dimming rate of light source 2B. The time on the horizontal axis represents the passage of time when the color temperature of the illumination light changes.

[0085] While the color temperature of the illumination light gradually changes from the light color of light source 2A (2700K) to the light color of light source 2B (6500K), the signal processing unit 34 acquires an instruction signal from the dimmer 33 at regular intervals. Then, the signal processing unit 34 generates a plurality of control signals M1 and N1 from the acquired instruction signal, and determines whether the control values m1 and n1 are below the lower limit value T1 in all of the generated plurality of control signals M1 and N1.

[0086] In the time interval of t0 ≦ t < t1, the operation is the same as that in the time interval of t0 ≦ t < t1 in Embodiment 2. Therefore, the description of the operation in this interval is omitted. In this interval, the illumination light is illumination light with a dimming rate corresponding to the control value m1 and a color temperature of the light color of light source 2A (2700K).

[0087] In the section of time t where t1≦t≦t2, the control values ​​m1, n1 of all of the control signals M1, N1 among the multiple control signals M1, N1 generated by the signal processing unit 34C are below the lower limit value T1. In this case, the signal processing unit 34C changes the control value n1 of at least one second control signal N1 among the second number (one in the example of FIG. 5) of second control signals N1 generated to a value n2 that is equal to or greater than the lower limit value T1, and does not change the control values ​​of the remaining (zero in the example of FIG. 5) second control signals. That is, the signal processor 34C changes the control value n1 of at least one of the second control signals N1 among the second number of second control signals N1 generated to a value n2 (lower limit value T1 in the example of FIG. 5) equal to or greater than the lower limit value T1 from the time when the control values ​​m1, n1 of all the control signals M1, N1 fall below the lower limit value T1 at time t1 until the control value n1 of at least one of the second control signals N1 among the second number of second control signals N1 generated becomes equal to or greater than the lower limit value T1 (lower limit value T1 in the example of FIG. 5) at time t2, and does not change the control values ​​of the remaining second control signals. Then, the signal processor 34 outputs the control signal N1 whose control value n1 has been changed to a value n2 equal to or greater than the lower limit value T1, the second control signal whose control value has not been changed, and the first control signal M1 whose control value m1 has not been changed to the corresponding control unit among the multiple control units 35A, 35B.

[0088] More specifically, in the second embodiment, since the second number is one, the signal processor 34C changes the control value n1 of the generated second control signal N1 to a value n2 equal to or greater than the lower limit T1, and does not change the control value m1 of the generated first control signal M1. The signal processor 34 then outputs the second control signal N1 in which the control value n1 has been changed to the control value n2 to the corresponding controller 35B, and outputs the first control signal M1 in which the control value m1 is not changed to the corresponding controller 35A.

[0089] Then, the plurality of control units 35A and 35B output currents corresponding to the control values m1 and n2 specified by the control signals M1 and N1 input from the signal processing unit 34C to the corresponding light sources 2A and 2B. More specifically, since the control value n2 of the control signal N1 input to the control unit 35B is a value equal to or greater than the lower limit value T1, the control unit 35B outputs a current corresponding to the control value n2 to the corresponding light source 2B. On the other hand, since the control value m1 of the control signal M1 input to the control unit 35A is a value less than the lower limit value T1, the control unit 35A stops the output of the current to the corresponding light source 2A according to the characteristics of the control unit 35A. As a result, the individual dimming rate Q1 of the light source 2A becomes zero, and the individual dimming rate Q2 of the light source 2B becomes the individual dimming rate corresponding to the control value n2.

[0090] Therefore, in this section (the section where t1 ≤ t ≤ t2), the illumination light has a dimming rate corresponding to the control value n2 and a color temperature of the color temperature of the light color of the light source 2B (6500K).

[0091] In this way, in this section (the section where t1 ≤ t ≤ t2), the control values m1 and n1 of all the generated control signals M1 and N1 are below the lower limit value T1. Therefore, originally, all the light sources 2A and 2B would stop emitting light and the illumination light would turn off. However, as described above, at least one of the control values n1 of the second control signals N1 of the second number generated is changed to a value n2 equal to or greater than the lower limit value T1. For this reason, the light source 2B corresponding to the changed second control signal N1 starts to emit light, and it is prevented that all of the plurality of light sources 2A and 2B turn off.

[0092] In the section where t2 < t ≤ t3, the operation is the same as that in the section where t2 < t ≤ t3 in the second embodiment. Therefore, the description of the operation in this section is omitted. In this section, the illumination light has a dimming rate corresponding to the control value n1 and a color temperature of the color temperature of the light color of the light source 2B (6500K).

[0093] (3) Effects As described above, in the lighting control device 3C according to the third embodiment, the multiple control signals in the first embodiment include a first number of first control signals M1 having a decreasing control value m1 and a second number of second control signals N1 having an increasing control value n1. The signal processor 34C changes the control value n1 in at least one of the second control signals N1 generated to a value n2 equal to or greater than the lower limit value T1 from when the control values ​​m1, n1 in all of the generated multiple control signals M1, N1 fall below the lower limit value T1 until the control value n1 in at least one of the second control signals N1 generated to a value n2 equal to or greater than the lower limit value T1. The signal processor 34C outputs the second control signal N1 in which the control value n1 has been changed to a value n2 equal to or greater than the lower limit value T1, the second control signal in which the control value has not been changed, and the first control signal M1 in which the control value m1 has not been changed to the corresponding control unit of the multiple control units 35A, 35B.

[0094] According to this configuration, by simply controlling the control value n1 in at least one of the second control signals N1 among the second number of second control signals N1 generated, to a value n2 equal to or greater than the lower limit value T1, it is possible to prevent the illumination light from being turned off by turning off all of the light sources 2A, 2B, for example, when controlling the dimming ratio of the illumination light under a low dimming rate.

[0095] (Embodiment 4) A lighting control device 3D and a lighting device 1D according to a fourth embodiment will be described with reference to FIGS. 1 and 6.

[0096] (1) Composition A lighting control device 3D according to embodiment 4 is a device that combines the operation of lighting control device 3B according to embodiment 2 and the operation of lighting control device 3C according to embodiment 3. Lighting control device 3D according to embodiment 4 is configured similarly to lighting control device 3B according to embodiment 2, except that the operation of signal processing unit 34D is different. Therefore, among the configurations of lighting control device 3D, the same configurations as those of lighting control device 3B are denoted by the same reference numerals and description thereof will be omitted (see FIG. 1).

[0097] When the signal processor 34D of the fourth embodiment acquires an instruction signal from the dimmer 33, the signal processor 34D generates a plurality of control signals (a first number (e.g., one) of first control signals M1 and a second number (e.g., one) of second control signals N1) based on the acquired instruction signal. Then, the signal processor 34D changes the control value m1 in at least one first control signal M1 of the first number of first control signals M1 generated to a value m2 (a first value, e.g., the lower limit value T1) equal to or greater than the lower limit value T1 until the control value n1 in at least one second control signal N1 of the second number of second control signals N1 generated becomes equal to or greater than the lower limit value T1 (e.g., the lower limit value T1) in the period from when the control values ​​m1, n1 in all of the generated plurality of control signals M1, N1 are below the lower limit value T1 until the control value n1 in at least one second control signal N1 of the generated second number of second control signals N1 becomes equal to or greater than the lower limit value T1 (e.g., the lower limit value T1), and changes the control value n1 in at least one second control signal N1 of the generated second number of second control signals N1 to a value n2 (a second value, e.g., the lower limit value T1) equal to or greater than the lower limit value T1. Then, the signal processing unit 34D outputs the first control signal M1 and the second control signal N1 in which the control values ​​m1, n1 are changed to values ​​m2, n2 that are equal to or greater than the lower limit value T1, and the first control signal and the second control signal in which the control values ​​are not changed, to corresponding control units among the multiple control units 35A, 35B.

[0098] (2) Operation Description The operation of the lighting control device 3D according to the fourth embodiment will be described with reference to FIG.

[0099] 6 illustrates an operation in which the dimming ratio (e.g., color temperature) of the illumination light gradually changes from the light color of the light source 2A (e.g., 2700K) to the light color of the light source 2B (e.g., 6500K) when the dimming ratio of the illumination light is, for example, a low dimming ratio (e.g., 1%), similarly to the example of FIG 3. In this case, the multiple control signals generated by the signal processing unit 34D include a first control signal M1 having a decreasing control value m1 and a second control signal N1 having an increasing control value n1, similarly to the second embodiment.

[0100] In the interval where \(t_0\leq t < t_1\), the operation is the same as that in the interval \(t_0\leq t < t_1\) of Embodiment 2. Therefore, the description of the operation in this interval is omitted. In this interval, the illumination light has a dimming rate corresponding to the control value \(m_1\), and the color temperature is the color temperature (2700K) of the light color of the light source 2A.

[0101] In the interval where \(t_1\leq t\leq t_2\), among the plurality of control signals \(M1, N1\) generated by the signal processing unit 34D, the control values \(m_1, n_1\) of all the control signals \(M1, N1\) are below the lower limit value \(T1\). In this case, the signal processing unit 34D changes the control value \(m_1\) of at least one of the first control signals \(M1\) among the first number of first control signals \(M1\) generated to a value \(m2\) that is equal to or greater than the lower limit value \(T1\), and changes the control value \(n_1\) of at least one of the second control signals \(N1\) among the second number of second control signals \(N1\) generated to a value \(n2\) that is equal to or greater than the lower limit value \(T1\). Also, the signal processing unit 34D does not change the control values of the remaining first control signals and the remaining second control signals. That is, when the control values \(m_1, n_1\) of all the control signals \(M1, N1\) are below the lower limit value \(T1\) at time \(t1\), the signal processing unit 34D, from time \(t1\) until the control value of at least one of the second control signals \(N1\) among the second number of second control signals generated at time \(t2\) becomes equal to or greater than the lower limit value \(T1\) (lower limit value \(T1\) in the example of FIG. 6), changes the control value \(m_1\) of at least one of the first control signals \(M1\) among the first number of first control signals \(M1\) generated to a value \(m2\) that is equal to or greater than the lower limit value \(T1\) (lower limit value \(T1\) in the example of FIG. 6), and changes the control value \(n_1\) of at least one of the second control signals \(N1\) among the second number of second control signals \(N1\) generated to a value \(n2\) that is equal to or greater than the lower limit value \(T1\) (lower limit value \(T1\) in the example of FIG. 6), and does not change the control values of the remaining first control signals and the remaining second control signals. Then, the signal processing unit 34D outputs the control signals \(M1, N1\) whose control values \(m_1, n_1\) have been changed to values \(m2, n2\) that are equal to or greater than the lower limit value \(T1\), and the first control signal and the second control signal whose control values have not been changed, to the corresponding control units among the plurality of control units \(35A, 35B\).

[0102] More specifically, in the second embodiment, since the first number and the second number are each one, the signal processor 34D changes the control value m1 of the one generated first control signal M1 to a value m2 equal to or greater than the lower limit value T1, and changes the control value n1 of the one generated second control signal N1 to a value n2 equal to or greater than the lower limit value T1. Then, the signal processor 34D outputs the first control signal M1 in which the control value m1 has been changed to the control value m2 to the corresponding controller 35A, and outputs the second control signal N1 in which the control value n1 has been changed to the control value n2 to the corresponding controller 35B.

[0103] The multiple control units 35A, 35B then output currents according to the control values ​​m2, n2 specified by the control signals M1, N1 input from the signal processing unit 34D to the corresponding light sources 2A, 2B. As a result, the individual dimming ratio Q1 of the light source 2A becomes an individual dimming ratio according to the control value m2, and the individual dimming ratio Q2 of the light source 2B becomes an individual dimming ratio according to the control value n2.

[0104] Therefore, in this section (the section t1≦t≦t2), the illumination light is composed of the light color of light source 2A with individual dimming rate Q1 according to control value m2 and the light color of light source 2B with individual dimming rate Q2 according to control value n2.

[0105] Thus, in this section (section t1≦t≦t2), the control values ​​m1, n1 of all the generated control signals M1, N1 are below the lower limit T1. Therefore, all the light sources 2A, 2B would not emit light, and the illumination light would be turned off. However, as described above, the control value m1 of at least one of the first control signals M1 among the first number of generated first control signals M1 is changed to a value m2 equal to or greater than the lower limit T1, and the control value n1 of at least one of the second control signals N1 among the second number of generated second control signals N1 is changed to a value n2 equal to or greater than the lower limit T1. Therefore, the light source 2A corresponding to the changed first control signal M1 and the light source 2B corresponding to the changed second control signal N1 emit light, and it is possible to prevent all of the light sources 2A, 2B from being turned off.

[0106] In the period where time t satisfies t2 < t ≤ t3, the operation is the same as that in the period of t2 < t ≤ t3 in Embodiment 2. Therefore, the description of the operation in this period is omitted. In this period, the illumination light has a dimming ratio corresponding to the control value n1 and a color temperature of the light color of the light source 2B (6500K).

[0107] (3) Effects As described above, in the lighting control device 3D according to Embodiment 4, in Embodiment 1, the plurality of control signals include a first number of first control signals M1 having a control value m1 with a decreasing tendency and a second number of second control signals N1 having a control value n1 with an increasing tendency. When the control values m1 and n1 are below the lower limit value T1 in all of the generated plurality of control signals M1 and N1, the signal processing unit 34D changes the control value n1 to a value equal to or higher than the lower limit value T1 in at least one of the second control signals N1 among the generated second number of second control signals N1 until the control value n1 becomes equal to or higher than the lower limit value T1 in at least one of the second control signals N1 among the generated second number of second control signals N1. The signal processing unit 34D outputs the first control signal M1 in which the control value m1 is changed to a value m2 equal to or higher than the lower limit value T1, the second control signal in which the control value n1 is changed to a value n2 equal to or higher than the lower limit value T1, the first control signal and the second control signal in which the control value is not changed, to the corresponding control unit among the plurality of control units 35A and 35B.

[0108] According to this configuration, by a simple control of changing the control value n1 of at least one of the second control signals N1 among the generated second number of second control signals N1 to a value n2 equal to or higher than the lower limit value T1, when controlling the dimming ratio of the illumination light under a low dimming ratio, it is possible to prevent the illumination light from turning off due to all the light sources 2A and 2B turning off.

[0109] (Embodiment 5) With reference to FIGS. 7 and 8, the lighting control device 3E and the lighting fixture 1E according to Embodiment 5 will be described.

[0110] The lighting fixture 1E of Embodiment 5 corresponds to the lighting fixture 1B of Embodiment 2 when including three light sources 2A, 2B, and 2C as a plurality of light sources.

[0111] (1) Composition As shown in FIG. 7, a lighting device 1E according to the fifth embodiment includes a plurality of light sources 2A, 2B, and 2C (three in the example of FIG. 7) and a lighting control device 3E according to the fifth embodiment.

[0112] The three light sources 2A, 2B, and 2C emit light of different colors. For example, the light source 2A emits red light, the light source 2B emits blue light, and the light source 2C emits green light.

[0113] The lighting control device 3E according to the fifth embodiment includes a rectifier circuit 31, a boost converter 32, a dimmer 33, a signal processor 34E, and a plurality of controllers 35A, 35B, and 35C. That is, the lighting control device 3E corresponds to the lighting control device 3B according to the second embodiment, which includes three controllers 35A, 35B, and 35C as a plurality of controllers. In other words, the lighting control device 3E is different from the lighting control device 3B in that it further includes a controller 35C. The lighting control device 3E is also different from the lighting control device 3B in that the operation of the signal processor 34E is different. The lighting control device 3E is configured similarly to the lighting control device 3B, except for the above differences. The same parts of the configuration of the lighting control device 3E as those of the lighting control device 3B according to the second embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0114] The control unit 35C includes a control circuit 351C and a step-down converter 352C, similar to the control units 35A and 35B. The control circuit 351C corresponds to the step-down converter 352C. The control circuit 351C controls the corresponding step-down converter 352C based on a corresponding control signal. The step-down converter 352C converts the output voltage of the boost converter 32 to a predetermined voltage based on the control from the control circuit 351C. More specifically, the step-down converter 352C includes, for example, an inductor, a switching element, a diode, and the like. The control circuit 351C PWM-controls the on-off switching of the switching element based on the control value (duty ratio) of the corresponding control signal. That is, the control circuit 351C periodically switches the switching element on and off, and controls the on-off switching of the switching element so that the ratio of the on time and the off time in each period becomes the ratio specified by the duty ratio.

[0115] In the fifth embodiment, a case is illustrated in which the dimming ratio (e.g., color temperature) of the illumination light gradually changes from a certain color temperature of a two-color mixture of red light of the light source 2A and green light of the light source 2C to a color temperature of one color of blue light of the light source 2B when the dimming ratio of the illumination light is, for example, a low dimming ratio (e.g., 1%). In this case, the multiple (e.g., three) control signals generated by the signal processing unit 34E include a first number (two in the fifth embodiment) of first control signals M1, P1 and a second number (one in the fifth embodiment) of second control signals N1 (see FIG. 8). The first number is at least one, and in the fifth embodiment, for example, two. The second number is at least one, and in the fifth embodiment, for example, one. The first control signal M1 is a signal that controls the current flowing through the light source 2A, and in the above case, has a control value m1 that indicates a decreasing tendency while the color temperature of the illumination light is changing. The first control signal P1 is a signal that controls the current flowing through the light source 2B, and in the above case, has a control value p1 that indicates a decreasing trend while the color temperature of the illumination light is changing. The second control signal N1 is a signal that controls the current flowing through the light source 2C, and in the above case, has a control value n1 that indicates an increasing trend while the color temperature of the illumination light is changing.

[0116] When the signal processor 34E of the fifth embodiment acquires an instruction signal from the dimmer 33, it generates a plurality of control signals M1, N1, P1 based on the acquired instruction signal. Then, the signal processor 34 changes the control value m1 in at least one first control signal M1 of the first number (e.g., two) generated first control signals M1, P1 to a value m2 (e.g., lower limit value T1) equal to or greater than the lower limit value T1 from when the control values ​​m1, n1, p1 fall below the lower limit value T1 in all of the generated plurality of control signals M1, N1, P1 until the control value n1 in at least one second control signal N1 of the generated second number (e.g., one) of second control signals N1 becomes equal to or greater than the lower limit value T1 (e.g., lower limit value T1). Then, the signal processing unit 34 outputs a first control signal M1 in which the control value m1 is changed to a value m2 greater than or equal to the lower limit value T1, a first control signal P1 in which the control value p1 is unchanged, and a second control signal N1 in which the control value n1 is unchanged to a corresponding control unit among the multiple control units 35A, 35B, 35C.

[0117] In addition, in embodiment 5, the lower limit value T1 set to each of the control values ​​m1, n1, p1 of the multiple control signals (the first number of first control signals M1, P1 and the second number of second control signals N1) is assumed to be the same value, but may be different values.

[0118] (2) Operation Description The operation of the lighting control device 3E according to the fifth embodiment will be described with reference to FIG.

[0119] 8 illustrates a case where the dimming ratio of the illumination light (e.g., color temperature) gradually changes from a certain color temperature of a two-color mixture of red light of light source 2A and green light of light source 2C to a color temperature of a single color of blue light of light source 2B when the dimming ratio of the illumination light is, for example, a low dimming ratio (e.g., 1%). In this case, the multiple control signals M1, N1, and P1 generated by the signal processing unit 34 include the first control signals M1 and P1 having the decreasing control values ​​m1 and p1 and the second control signal N1 having the increasing control value n1, as described above.

[0120] In the example of FIG. 8, the horizontal axis represents time, the left vertical axis represents the control values m1, n1, p1 of the plurality of control signals M1, N1, P1 generated by the signal processing unit 34E, and the right vertical axis represents the individual dimming rates Q1, Q2, Q3 of each of the plurality of light sources 2A, 2B, 2C. The individual dimming rate Q1 represents the dimming rate of the light source 2A, the individual dimming rate Q2 represents the dimming rate of the light source 2B, and the individual dimming rate Q3 represents the dimming rate of the light source 2C. The time on the horizontal axis represents the passage of time when the color temperature of the illumination light changes.

[0121] While the color temperature of the illumination light gradually changes from a certain color temperature of the two-color mixture of the red light of the light source 2A and the green light of the light source 2C to the color temperature of one color of the blue light of the light source 2B, the signal processing unit 34E acquires an instruction signal from the dimmer 33 at regular intervals. Then, the signal processing unit 34E generates a plurality of control signals M1, N1, P1 from the acquired instruction signal, and determines whether the control values m1, n1, p1 in all of the generated plurality of control signals M1, N1, P1 are below the lower limit value T1.

[0122] In the time interval of t0 ≦ t < t1, among the plurality of control signals M1, N1, P1 generated by the signal processing unit 34E, the control values m1, p1 of the first control signals M1, P1 are equal to or higher than the lower limit value T1, and the control value n1 of the second control signal N1 is less than the lower limit value T1. That is, the control values m1, n1, p1 are not the lower limit value T1 in all of the plurality of control signals M1, N1, P1. In this case, the signal processing unit 34E does not change the control values m1, n1, p1 of each of the generated plurality of control signals M1, N1, P1. Therefore, the signal processing unit 34E outputs the generated plurality of control signals M1, N1, P1 to the corresponding control units 35A, 35B, 35C without changing their control values m1, n1, p1.

[0123] Then, the plurality of control units 35A, 35B, and 35C output currents corresponding to the control values m1, n1, and p1 specified by the control signals M1, N1, and P1 input from the signal processing unit 34E to the corresponding light sources 2A, 2B, and 2C. More specifically, since the control value m1 of the control signal M1 input to the control unit 35A is a value equal to or greater than the lower limit value T1, the control unit 35A outputs a current corresponding to the control value m1 to the corresponding light source 2A. Since the control value n1 of the control signal N1 input to the control unit 35B is a value less than the lower limit value T1, the control unit 35B stops the output of current to the corresponding light source 2B according to the characteristics of the control unit 35B. Since the control value p1 of the control signal P1 input to the control unit 35C is a value equal to or greater than the lower limit value T1, the control unit 35C outputs a current corresponding to the control value p1 to the corresponding light source 2C. As a result, the individual dimming rate Q1 of the light source 2A becomes the individual dimming rate corresponding to the control value m1, the individual dimming rate Q2 of the light source 2B becomes zero, and the individual dimming rate Q3 of the light source 2C becomes the individual dimming rate corresponding to the control value p1.

[0124] Therefore, in this section (t0 ≦ t < t1), the illumination light becomes illumination light with a color temperature of two-color mixing of the red light of the light source 2A and the green light of the light source 2C.

[0125] In the section where t1 ≦ t < t2, among the plurality of control signals M1, N1, and P1 generated by the signal processing unit 34E, the control value m1 of the first control signal M1 is equal to or greater than the lower limit value T1, and the control value p1 of the first control signal P1 and the control value n1 of the second control signal N1 are less than the lower limit value T1. That is, the control values m1, n1, and p1 of all the control signals among the plurality of control signals M1, N1, and P1 are not the lower limit value T1. In this case, the signal processing unit 34E does not change the control values m1, n1, and p1 of each of the plurality of generated control signals M1, N1, and P1. Therefore, the signal processing unit 34E outputs the plurality of generated control signals M1, N1, and P1 to the corresponding control units 35A, 35B, and 35C without changing their control values m1, n1, and p1.

[0126] Then, the plurality of control units 35A, 35B, 35C output currents corresponding to the control values m1, n1, p1 specified by the control signals M1, N1, P1 input from the signal processing unit 34E to the corresponding light sources 2A, 2B, 2C. More specifically, since the control value m1 of the control signal M1 input to the control unit 35A is a value equal to or greater than the lower limit value T1, the control unit 35A outputs a current corresponding to the control value m1 to the corresponding light source 2A. Since the control value n1 of the control signal N1 input to the control unit 35B is a value less than the lower limit value T1, the control unit 35B stops the output of the current to the corresponding light source 2B according to the characteristics of the control unit 35B. Since the control value p1 of the control signal P1 input to the control unit 35C is a value less than the lower limit value T1, the control unit 35C stops the output of the current to the corresponding light source 2C according to the characteristics of the control unit 35C. As a result, the individual dimming rate Q1 of the light source 2A becomes the individual dimming rate corresponding to the control value m1, the individual dimming rate Q2 of the light source 2B becomes zero, and the individual dimming rate Q3 of the light source 2C becomes zero.

[0127] Therefore, in this section (t1 ≦ t < t2), the illumination light becomes illumination light of the color temperature of only the red light of the light source 2A.

[0128] In the section of time t where t2≦t≦t3, the control values ​​m1, n1, p1 of all of the control signals M1, N1, P1 among the multiple control signals M1, N1, P1 generated by the signal processor 34E are below the lower limit value T1. In this case, the signal processor 34E changes the control value m1 of at least one first control signal M1 among the first number (two in the fifth embodiment) of first control signals M1, P1 generated to a value m2 (the lower limit value T1 in the example of FIG. 8) that is equal to or greater than the lower limit value T1, and does not change the control values ​​p1 of the remaining first control signals P1. That is, the signal processor 34E changes the control value m1 of at least one of the first control signals M1, P1 generated in the first number of first control signals M1, P1 to a value m2 (lower limit value T1 in the example of FIG. 8) equal to or greater than the lower limit value T1 from the time when the control values ​​m1, n1, p1 of all the control signals M1, N1, P1 fall below the lower limit value T1 at time t2 until the control value n1 of at least one of the second control signals N1 generated in the second number (one in the fifth embodiment) becomes equal to or greater than the lower limit value T1 (lower limit value T1 in the example of FIG. 8) at time t3, and does not change the control value p1 of the remaining first control signal P1. The signal processor 34E also does not change the control value n1 of the second number of second control signals N1 generated. Then, the signal processing unit 34E outputs a first control signal M1 in which the control value m1 is changed to a value m2 greater than or equal to the lower limit value T1, a first control signal P1 in which the control value p1 is unchanged, and a second control signal N1 in which the control value n1 is unchanged to a corresponding control unit among the multiple control units 35A, 35B.

[0129] Then, the multiple control units 35A, 35B, and 35C output currents according to the control values ​​m2, n1, and p1 designated by the control signals M1, N1, and P1 input from the signal processing unit 34E to the corresponding light sources 2A, 2B, and 2C. More specifically, the control value m2 of the control signal M1 input to the control unit 35A is equal to or greater than the lower limit T1, so the control unit 35A outputs currents according to the control value m2 to the corresponding light source 2A. The control value n1 of the control signal N1 input to the control unit 35B is less than the lower limit T1, so the control unit 35B stops outputting current to the corresponding light source 2B due to the characteristics of the control unit 35B. The control value p1 of the control signal P1 input to the control unit 35C is less than the lower limit T1, so the control unit 35C stops outputting current to the corresponding light source 2C due to the characteristics of the control unit 35C. As a result, the individual dimming rate Q1 of the light source 2A becomes an individual dimming rate according to the control value m2, the individual dimming rate Q2 of the light source 2B becomes zero, and the individual dimming rate Q3 of the light source 2C becomes zero.

[0130] Therefore, in this section (t2≦t≦t3), the illumination light has a color temperature of only one color, that is, red light from the light source 2A.

[0131] Thus, in this section (t2≦t≦t3), the control values ​​m1, n1, p1 of all the generated control signals M1, N1, P1 are below the lower limit T1. Therefore, all the light sources 2A, 2B, 2C would normally stop emitting light, and the illumination light would be turned off. However, as described above, the control value m1 of at least one of the first control signals M1, P1 among the first number of generated first control signals M1, P1 is changed to a value m2 that is equal to or greater than the lower limit T1. Therefore, the light source 2A corresponding to the first control signal M1 emits light, and the turning off of all of the multiple light sources 2A, 2B, 2C is prevented.

[0132] In the interval where t3 < t ≤ t4, among the plurality of control signals M1, N1, P1 generated by the signal processing unit 34E, the control values m1, p1 of the first number (two in Embodiment 5) of the first control signals M1, P1 are less than the lower limit value T1, and the control value n1 of at least one of the second control signals N1 of the second number (one in Embodiment 5) of the second control signals N1 is a value greater than or equal to the lower limit value T1. That is, the control values m1, n1, p1 of all the control signals among the plurality of control signals M1, N1, P1 are not the lower limit value T1. In this case, the signal processing unit 34E does not change the control values m1, n1, p1 of each of the plurality of generated control signals M1, N1, P1. Therefore, the signal processing unit 34E outputs the plurality of generated control signals M1, N1, P1 to the corresponding control units 35A, 35B, 35C without changing their control values m1, n1, p1.

[0133] Then, the plurality of control units 35A, 35B, 35C output currents corresponding to the control values m1, n1, p1 specified by the control signals M1, N1, P1 input from the signal processing unit 34E to the corresponding light sources 2A, 2B, 2C. More specifically, since the control value m1 of the control signal M1 input to the control unit 35A is a value less than the lower limit value T1, the control unit 35A stops the output of the current to the corresponding light source 2A according to the characteristics of the control unit 35A. Since the control value n1 of the control signal N1 input to the control unit 35B is a value greater than or equal to the lower limit value T1, the control unit 35B outputs a current corresponding to the control value n1 to the corresponding light source 2B. Since the control value p1 of the control signal P1 input to the control unit 35C is a value less than the lower limit value T1, the control unit 35C stops the output of the current to the corresponding light source 2C according to the characteristics of the control unit 35C. As a result, the individual dimming rate Q1 of the light source 2A becomes zero, and the individual dimming rate Q2 of the light source 2B becomes the individual dimming rate corresponding to the control value n1. The individual dimming rate Q3 of the light source 2C becomes zero.

[0134] Therefore, in this interval (t3 < t ≤ t4), the illumination light becomes illumination light with the color temperature of the blue light of the light source 2B.

[0135] (3) Comparative Example As Comparative Example 3, in the lighting control device 3E according to the fifth embodiment, when the control values ​​m1, n1, p1 of all the generated control signals M1, N1, P1 are below the lower limit value T1 (i.e., in the section of t2≦t≦t3), the signal processing unit 34E does not change the control values ​​m1, n1, p1 of all the generated control signals M1, N1, P1. In this case, as shown in FIG. 9, in the section of t2≦t≦t3, the control values ​​m1, n1, p1 of all the control signals M1, N1, P1 are below the lower limit value T1, so that all the control units 35A, 35B, 35C stop outputting currents to the corresponding light sources 2A, 2B, 2C according to the characteristics of the control units 35A, 35B, 35C. As a result, in Comparative Example 2, in the section of t2≦t≦t3, all the light sources 2A, 2B, 2C are turned off, and the illumination light is turned off. That is, in Comparative Example 3, when the color temperature of the illumination light is gradually changed from a color temperature of a mixture of two colors, the red light of light source 2A and the green light of light source 2C, to a color temperature of a single color, the blue light of light source 2B, the illumination light is turned off against the user's will in an intermediate section (section t2≦t≦t3), which causes the user to feel uncomfortable.

[0136] In contrast, in the lighting control device 3E according to the fifth embodiment, as described above, when the control values ​​m1, n1, p1 of all the control signals M1, N1, P1 are below the lower limit T1 (i.e., in the section t2≦t≦t3), the signal processor 34E changes the control value m1 of at least one of the first control signals M1, P1 generated in the first number to a value m2 equal to or greater than the lower limit T1. Therefore, when the color temperature of the illumination light is gradually changed from a certain color temperature of a two-color mixture of the red light of the light source 2A and the green light of the light source 2C to a color temperature of a single color of the blue light of the light source 2B, it is possible to prevent the illumination light from being turned off against the user's will in the middle section (the section t2≦t≦t3). Therefore, the user does not feel discomfort.

[0137] (4) Effects As described above, in the lighting control device 3E according to the fifth embodiment, the multiple control signals M1, N1, P1 in the first embodiment include a first number of first control signals M1, P1 having a decreasing control value m1, p1 and a second number of second control signals N1 having an increasing control value n1. The signal processing unit 34E changes the control value m1 in at least one first control signal M1 among the first number of first control signals M1, P1 generated to a value m2 equal to or greater than the lower limit value T1 from when the control value m1, n1, p1 in all of the generated multiple control signals M1, N1, P1 falls below the lower limit value T1 until the control value n1 in at least one second control signal N1 among the generated second number of second control signals N1 becomes equal to or greater than the lower limit value T1. The signal processing unit 34E outputs a first control signal M1 in which the control value m1 is changed to a value m2 greater than or equal to the lower limit value T1, a first control signal P1 in which the control value p1 is unchanged, and a second control signal N1 in which the control value n1 is unchanged to a corresponding control unit among the multiple control units 35A, 35B, 35C.

[0138] According to this configuration, by simply controlling the control value m1 of at least one first control signal M1 among the first number of first control signals M1, P1 generated to a value m2 that is equal to or greater than the lower limit value T1, it is possible to prevent all of the multiple light sources 2A, 2B, 2C from being turned off when the control values ​​of all of the multiple generated control signals M1, N1, P1 fall below the lower limit value T1.

[0139] (Embodiment 6) A lighting control device 3F and a lighting device 1F according to a sixth embodiment will be described with reference to FIGS.

[0140] (1) Configuration Description In a lighting control device 3E of embodiment 5, a signal processing unit 34E changes the control value m1 to a value m2 that is greater than or equal to the lower limit value T1 in at least one first control signal M1 of the first number of first control signals M1, P1 generated from the time when the control values ​​m1, n1, p1 fall below the lower limit value T1 in all of the generated multiple control signals M1, N1, P1 until the control value n1 becomes greater than or equal to the lower limit value T1 in at least one second control signal N1 of the second number of second control signals N1 generated.

[0141] In contrast, in the lighting control device 3F of embodiment 6, the signal processing unit 34F changes the control value n1 to a value n2 that is greater than or equal to the lower limit value T1 in at least one second control signal among the second number of second control signals N1 generated from the time when the control values ​​m1, n1, p1 fall below the lower limit value T1 in all of the generated multiple control signals M1, N1, P1 until the control value n1 becomes greater than or equal to the lower limit value T1 in at least one second control signal N1 among the second number of second control signals N1 generated.

[0142] As described above, lighting control device 3F according to embodiment 6 is configured similarly to lighting control device 3E according to embodiment 5, except that the operation of signal processing unit 34F is different. Therefore, among the configurations of lighting control device 3F, the same configurations as those of lighting control device 3E are denoted by the same reference numerals and descriptions thereof will be omitted.

[0143] When the signal processor 34F of the sixth embodiment acquires an instruction signal from the dimmer 33, it generates a plurality of control signals M1, N1, P1 based on the acquired instruction signal. Then, the signal processor 34F changes the control value n1 in at least one second control signal N1 among the second number of second control signals N1 generated to a value n2 (e.g., lower limit value T1) equal to or greater than the lower limit value T1 from when the control values ​​m1, n1, p1 fall below the lower limit value T1 in all of the generated plurality of control signals M1, N1, P1 until the control value n1 in at least one second control signal N1 among the second number of second control signals N1 generated becomes equal to or greater than the lower limit value T1 (e.g., lower limit value T1). Then, the signal processing unit 34F outputs a second control signal N1 in which the control value n1 is changed to a value n2 greater than or equal to the lower limit value T1, a second control signal in which the control value is not changed, and first control signals M1, P1 in which the control values ​​m1, p1 are not changed to corresponding control units among the multiple control units 35A, 35B, 35C.

[0144] (2) Operation Description The operation of a lighting control device 3F according to the third embodiment will be described with reference to FIG.

[0145] 10 illustrates a case where the dimming ratio of the illumination light (e.g., color temperature) gradually changes from a certain color temperature of a two-color mixture of red light of light source 2A and green light of light source 2C to a color temperature of a single color of blue light of light source 2B when the dimming ratio of the illumination light is, for example, a low dimming ratio (e.g., 1%), similarly to the example of FIG 8. In this case, the multiple control signals M1, N1, P1 generated by the signal processing unit 34F include the first control signals M1, P1 having the decreasing control values ​​m1, p1 and the second control signal N1 having the increasing control value n1, as described above.

[0146] In the example of FIG. 10, the horizontal axis represents time, the left vertical axis represents the control values m1, n1, p1 of a plurality of control signals M1, N1, P1 generated by the signal processing unit 34E, and the right vertical axis represents the individual dimming rates Q1, Q2, Q3 of each of the plurality of light sources 2A, 2B, 2C. The individual dimming rate Q1 represents the dimming rate of the light source 2A, the individual dimming rate Q2 represents the dimming rate of the light source 2B, and the individual dimming rate Q3 represents the dimming rate of the light source 2C. The time on the horizontal axis represents the passage of time when the color temperature of the illumination light changes.

[0147] While the color temperature of the illumination light gradually changes from a certain color temperature of the two-color mixture of the red light of the light source 2A and the green light of the light source 2C to the color temperature of the single color of the blue light of the light source 2B, the signal processing unit 34E acquires an instruction signal from the dimmer 33 at regular intervals. Then, the signal processing unit 34E generates a plurality of control signals M1, N1, P1 from the acquired instruction signal, and determines whether the control values m1, n1, p1 of the control signals are below the lower limit value T1 in all of the generated plurality of control signals M1, N1, P1.

[0148] In the interval where t0 ≦ t < t1, since the operation in the interval of t0 ≦ t < t1 in Embodiment 5 is the same, the operation in this interval is omitted. In this interval, the illumination light is the illumination light with the color temperature of the two-color mixture of the red light of the light source 2A and the green light of the light source 2C.

[0149] In the interval where t1 ≦ t < t2, since the operation in the interval of t1 ≦ t < t2 in Embodiment 5 is the same, the operation in this interval is omitted. In this interval, the illumination light is the illumination light with the color temperature of the single color of the red light of the light source 2A.

[0150] In the section of time t where t2≦t≦t3, the control values ​​m1, n1, p1 of all of the control signals M1, N1, P1 among the multiple control signals M1, N1, P1 generated by the signal processor 34F are below the lower limit value T1. In this case, the signal processor 34F changes the control value n1 of at least one second control signal N1 among the second number (one in the fifth embodiment) of second control signals N1 generated to a value n2 that is equal to or greater than the lower limit value T1, and does not change the control values ​​of the remaining (zero in the fifth embodiment) second control signals. That is, the signal processor 34F changes the control value n1 of at least one of the second control signals N1 among the second number of second control signals N1 generated to a value n2 (lower limit value T1 in the example of FIG. 10) equal to or greater than the lower limit value T1 from the time when the control values ​​m1, n1, p1 of all the control signals M1, N1, P1 fall below the lower limit value T1 at time t2 until the control value n1 of at least one of the second control signals N1 among the second number of second control signals N1 generated becomes equal to or greater than the lower limit value T1 (lower limit value T1 in the example of FIG. 10) at time t3, and does not change the control values ​​of the remaining second control signals. In addition, the signal processor 34F does not change the control values ​​m1, p1 of the first number of first control signals M1, P1 generated. Then, the signal processing unit 34F outputs a second control signal N1 in which the control value n1 is changed to a value n2 greater than or equal to the lower limit value T1, a second control signal in which the control value is not changed, and first control signals M1, P1 in which the control values ​​m1, p1 are not changed to corresponding control units among the multiple control units 35A, 35B.

[0151] Then, the plurality of control units 35A, 35B, and 35C output currents corresponding to the control values m1, n2, and p1 specified by the control signals M1, N1, and P1 input from the signal processing unit 34F to the corresponding light sources 2A, 2B, and 2C. More specifically, since the control value m1 of the control signal M1 input to the control unit 35A is a value less than the lower limit value T1, the control unit 35A stops outputting current to the corresponding light source 2A according to the characteristics of the control unit 35A. Since the control value n2 of the control signal N1 input to the control unit 35B is a value greater than or equal to the lower limit value T1, the control unit 35B outputs a current corresponding to the control value n2 to the corresponding light source 2B. Since the control value p1 of the control signal P1 input to the control unit 35C is a value less than the lower limit value T1, the control unit 35C stops outputting current to the corresponding light source 2C according to the characteristics of the control unit 35C. As a result, the individual dimming rate Q1 of the light source 2A becomes zero, the individual dimming rate Q2 of the light source 2B becomes the individual dimming rate corresponding to the control value n2, and the individual dimming rate Q3 of the light source 2C becomes zero.

[0152] Therefore, in this period (t2 ≦ t ≦ t3), the illumination light becomes illumination light with the color temperature of only the blue light of the light source 2B.

[0153] Thus, in this period (t2 ≦ t ≦ t3), the control values m1, n1, and p1 of all the generated control signals M1, N1, and P1 are below the lower limit value T1. Therefore, originally, all the light sources 2A, 2B, and 2C would stop emitting light and the illumination light would turn off. However, as described above, the control value n1 of at least one of the second control signals N1 among the generated second number of second control signals N1 is changed to a value n2 greater than or equal to the lower limit value T1. Therefore, the light source 2B corresponding to the changed second control signal N1 starts to emit light, preventing all of the plurality of light sources 2A, 2B, and 2C from turning off.

[0154] In the period when t3 < t ≦ t4, since the operation in the period of t3 < t ≦ t4 in Embodiment 5 is the same, the operation in this period is omitted. In this period, the illumination light becomes illumination light with the color temperature of the blue light of the light source 2B.

[0155] (3) Effects As described above, in the lighting control device 3F according to the sixth embodiment, the plurality of control signals include a first number of first control signals M1, P1 having decreasing control values ​​m1, p1 and a second number of second control signals N1 having an increasing control value n1. The signal processor 34F changes the control value n1 in at least one second control signal N1 among the second number of second control signals N1 generated to a value n2 equal to or greater than the lower limit value T1 from when the control values ​​m1, n1, p1 in all of the generated plurality of control signals M1, N1, P1 fall below the lower limit value T1 until the control value n1 in at least one second control signal N1 among the second number of second control signals N1 generated becomes equal to or greater than the lower limit value T1. The signal processing unit 34F outputs a second control signal N1 in which the control value n1 is changed to a value n2 greater than or equal to the lower limit value T1, a second control signal in which the control value is not changed, and first control signals M1, P1 in which the control values ​​m1, p1 are not changed to corresponding control units among the multiple control units 35A, 35B, 35C.

[0156] According to this configuration, by simply controlling the control value n1 of at least one of the second control signals N1 among the generated second number of second control signals N1 to a value n2 equal to or greater than the lower limit value T1, it is possible to prevent the illumination light from being turned off by turning off all of the light sources 2A, 2B, 2C when controlling the dimming ratio (e.g., color temperature) of the illumination light under a low dimming rate, for example.

[0157] (4) Variations The first to sixth embodiments and their modified examples may be combined and implemented.

[0158] (Aspect) The present specification discloses the following aspects.

[0159] The lighting control device (3; 3B; 3C; 3D; 3E; 3F) of the first aspect controls illumination light including a plurality of lights having different light colors emitted from a plurality of light sources (2A, 2B; 2A, 2B, 2C). The lighting control device (3; 3B; 3C; 3D; 3E; 3F) includes a signal processing unit (34; 34B; 34C; 34D; 34E; 34F) and a plurality of control units (35A, 35B; 35A, 35B, 35C). The signal processing unit (3; 3B; 3C; 3D; 3E; 3F) corresponds to the plurality of light sources (2A, 2B; 2A, 2B, 2C) and generates a plurality of control signals (M1, N1; M1, N1, P1) for controlling the current flowing through the corresponding light sources (2A, 2B; 2A, 2B, 2C) based on the instruction signal indicating the dimming rate of the illumination light and the dimming ratio of the plurality of light sources (2A, 2B; 2A, 2B, 2C). The plurality of control units (35A, 35B; 35A, 35B, 35C) correspond to the plurality of light sources (2A, 2B; 2A, 2B, 2C) and the plurality of control signals (M1, N1; M1, N1, P1), and output a current according to the control value (m1, n1; m1, n1, p1) designated by the corresponding control signal to the corresponding light source (2A, 2B; 2A, 2B, 2C). A lower limit value (T1) is set for each of the plurality of control units (35A, 35B; 35A, 35B, 35C) with respect to the control value (m1, n1; m1, n1, p1) of the corresponding control signal (M1, N1; M1, N1, P1). Each of the plurality of control units (35A, 35B; 35A, 35B, 35C) stops outputting a current to the corresponding light source (2A, 2B; 2A, 2B, 2C) when the control value (m1, n1; m1, n1, p1) of the corresponding control signal (M1, N1; M1, N1, P1) is equal to or less than the lower limit value (T1). When the control values ​​(m1, n1; m1, n1, p1) in all of the generated control signals (M1, N1; M1, N1, P1) are below the lower limit value (T1), the signal processing unit (34; 34B; 34C; 34D; 34E; 34F) changes the control value in at least one of the generated control signals (m1, n1; m1, n1, p1) to a value equal to or greater than the lower limit value (T1).The signal processing unit (34; 34B; 34C; 34D; 34E; 34F) outputs the control signals (M1, N1; M1, N1, P1) whose control values ​​(m1; n1; m1, n1) have been changed to values ​​equal to or greater than the lower limit value (T1), and the control signals (M1, N1; M1, N1, P1) whose control values ​​(m1; n1; m1, n1, p1) have not been changed, to corresponding control units among the multiple control units (35A, 35B; 35A, 35B, 35C).

[0160] According to this configuration, when the control values ​​(m1; n1; m1, n1, p1) in all of the generated control signals (M1, N1; M1, N1, P1) are below the lower limit (T1), the control value in at least one of the multiple control signals (M1, N1; M1, N1, P1) is changed to a value equal to or greater than the lower limit (T1). Therefore, when the control values ​​in all of the generated control signals (M1, N1; M1, N1, P1) are below the lower limit (T1), it is possible to prevent all of the multiple light sources (2A, 2B; 2A, 2B, 2C) from being turned off. This makes it possible to prevent the illumination light from being turned off by turning off all of the light sources (2A, 2B; 2A, 2B, 2C) when controlling the dimming ratio (e.g., color temperature) of the illumination light under a low dimming rate.

[0161] In the lighting control device (3B, 3E) of the second aspect, in the first aspect, the multiple control signals (M1, N1; M1, N1, P1) include a first number of first control signals (M1; M1, P1) having a control value (m1; m1, p1) tending to decrease, and a second number of second control signals (N1) having a control value (n1) tending to increase. The signal processing unit (34B, 34E) changes the control value (m1) in at least one first control signal (M1) among the first number of first control signals (M1, N1; M1, N1, P1) generated to a value (m2) that is equal to or greater than the lower limit value (T1) from the time when the control values ​​(m1, n1; m1, n1, p1) in all of the generated multiple control signals (M1, N1; M1, N1, P1) fall below the lower limit value (T1) until the control value (n1) in at least one second control signal (N1) among the second number of second control signals (N1) generated becomes equal to or greater than the lower limit value (T1). The signal processing unit (34B, 34E) outputs the first control signal (M1) in which the control value (m1) has been changed to a value (m2) equal to or greater than the lower limit value (T1), and the first control signal (P1) and the second control signal (N1) in which the control values ​​(n1; n1, p1) have not been changed, to a corresponding control unit among the multiple control units (35A, 35B; 35A, 35B, 35C).

[0162] According to this configuration, by simply controlling the control value (m1) in at least one first control signal (M1) among the first number of first control signals (M1; M1, P1) generated to a value (m2) equal to or greater than the lower limit value (T1), it is possible to prevent the illumination light from being turned off by turning off all of the light sources (2A, 2B; 2A, 2B, 2C) when controlling the dimming ratio (e.g., color temperature) of the illumination light under a low dimming rate, for example.

[0163] In the lighting control device (3C; 3F) of the third aspect, in the first aspect, the multiple control signals (M1, N1; M1, N1, P1) include a first number of first control signals (M1; M1, P1) having a control value (m1; m1, p1) tending to decrease, and a second number of second control signals (N1) having a control value (n1) tending to increase. The signal processing unit (34C; 34F) changes the control value (n1) in at least one second control signal (N1) among the second number of second control signals (N1) generated to a value (n2) that is equal to or greater than the lower limit value (T1) from the time when the control values ​​(m1, n1; m1, n1, p1) in all of the generated multiple control signals (M1, N1; M1, N1, P1) fall below the lower limit value (T1) until the control value (n1) in at least one second control signal (N1) among the second number of second control signals (N1) generated becomes equal to or greater than the lower limit value (T1). The signal processing unit (34C; 34F) outputs the second control signal (N1) in which the control value (n1) has been changed to a value (n2) equal to or greater than the lower limit value (T1), and the first control signal (M1; M1, P1) and the second control signal in which the control values ​​(m1; m1, p1) have not been changed, to a corresponding control unit among the multiple control units (35A, 35B; 35A, 35B, 35C).

[0164] According to this configuration, by simply controlling the control value (n1) in at least one second control signal (N1) among the second number of second control signals (N1) generated to a value (n2) equal to or greater than the lower limit value (T1), it is possible to prevent the illumination light from being turned off by turning off all of the light sources (2A, 2B; 2A, 2B, 2C) when controlling the dimming ratio (e.g., color temperature) of the illumination light under a low dimming rate, for example.

[0165] In the lighting control device (3D) of the fourth aspect, in the first aspect, the multiple control signals (M1, N1; M1, N1, P1) include a first number of first control signals (M1; M1, P1) having a control value (m1; m1, p1) tending to decrease, and a second number of second control signals (N1) having a control value (n1) tending to increase. The signal processing unit (34D) changes the control value (m1, n1; m1, n1, p1) in at least one first control signal (M1) among the first number of first control signals (M1; M1, P1) generated to a first value (m2) that is equal to or greater than the lower limit value (T1) from the time when the control values ​​(m1, n1; m1, n1, p1) in all of the generated multiple control signals (M1, N1; M1, N1, P1) fall below the lower limit value (T1) until the control value (n1) in at least one second control signal (N1) among the generated second number of second control signals (N1) becomes equal to or greater than the lower limit value (T1), and changes the control value (n1) in at least one second control signal (N1) among the generated second number of second control signals (N1) to a second value (n2) that is equal to or greater than the lower limit value (T1). The signal processing unit (34D) outputs the first control signal (M1) and the second control signal (N1) in which the control value (m1, n1) has been changed to a value (m2, n2) equal to or greater than the lower limit value (T1), and the first control signal (P1) and the second control signal in which the control value (p1) has not been changed, to a corresponding control unit among the multiple control units (35A, 35B, 35C).

[0166] According to this configuration, with simple control of changing the control value (m1) in at least one first control signal (M1) among the first number of first control signals (M1; M1, P1) generated to a value (m2) equal to or greater than the lower limit value (T1), and changing the control value (n1) in at least one second control signal (N1) among the second number of second control signals (N1) generated to a value (n2) equal to or greater than the lower limit value (T1), it is possible to prevent all of the multiple light sources (2A, 2B; 2A, 2B, 2C) from being turned off when the control values ​​(m1, n1; m1, n1, p1) in all of the multiple control signals (M1, N1; M1, N1, P1) generated are below the lower limit value (T1).

[0167] In a lighting control device (3; 3B; 3C; 3D; 3E; 3F) of a fifth aspect, in any one of the first to fourth aspects, the lower limit value (T1) set in the multiple control units (35A, 35B; 35A, 35B, 35C) includes values ​​that are different from each other.

[0168] According to this configuration, the lower limit value (T1) set in the plurality of control units (35A, 35B; 35A, 35B, 35C) can be made different from one another, so that the lower limit value (T1) can be set to an optimal value according to each control unit (35A, 35B; 35A, 35B, 35C).

[0169] A lighting device (1; 1B; 1C; 1D; 1E; 1F) of a sixth aspect includes a plurality of light sources (2A, 2B; 2A, 2B, 2C) and any one of the lighting control devices (3; 3B; 3C; 3D; 3E; 3F) of the first to fifth aspects.

[0170] According to this configuration, it is possible to provide lighting devices (1; 1B; 1C; 1D; 1E; 1F) that achieve the effects of the lighting control device (3; 3B; 3C; 3D; 3E; 3F).

[0171] The seventh aspect of the lighting control method controls illumination light including a plurality of lights having different light colors emitted from a plurality of light sources (2A, 2B; 2A, 2B, 2C). The lighting control method includes a signal processing step (step S2) and a control step (steps S3 to S6). In the signal processing step (step S2), a plurality of control signals are generated to correspond to the plurality of light sources (2A, 2B; 2A, 2B, 2C) and to control current flowing through the corresponding light sources (2A, 2B; 2A, 2B, 2C) based on instruction signals instructing the dimming rate of the illumination light and the dimming ratios of the plurality of light sources (2A, 2B; 2A, 2B, 2C). In the control process (steps S3 to S6), a current corresponding to a control value designated by the corresponding control signal is output from a plurality of control units (35A, 35B; 35A, 35B, 35C) corresponding to the plurality of light sources (2A, 2B; 2A, 2B, 2C) and a plurality of control signals to the corresponding light sources (2A, 2B; 2A, 2B, 2C). A lower limit value for the control value of the corresponding control signal is set in each of the plurality of control units (35A, 35B; 35A, 35B, 35C). When the control value designated by the corresponding control signal is equal to or lower than the lower limit value, each of the plurality of control units (35A, 35B; 35A, 35B, 35C) stops outputting a current to the corresponding light source (2A, 2B; 2A, 2B, 2C). In the signal processing step (steps S3 to S6), when the control values ​​of all the generated control signals are below the lower limit (Yes in step S3), the control value of at least one of the control signals is changed to a value equal to or greater than the lower limit (step S4). In the signal processing step (steps S3 to S6), the control signal whose control value has been changed to a value equal to or greater than the lower limit and the control signal whose control value has not been changed are output to the corresponding control unit among the multiple control units (step S6).

[0172] According to this configuration, when the control value falls below the lower limit in all of the generated control signals (Yes in step S3), the control value in at least one of the multiple control signals is changed to a value equal to or greater than the lower limit (step S4). Therefore, when the control value falls below the lower limit in all of the generated control signals, it is possible to prevent all of the multiple light sources from being turned off. This makes it possible to prevent the illumination light from being turned off by turning off all of the light sources (2A, 2B; 2A, 2B, 2C) when controlling the dimming ratio (e.g., color temperature) of the illumination light under a low dimming rate, for example.

[0173] A program according to an eighth aspect causes one or more processors to execute the lighting control method according to the seventh aspect.

[0174] According to this configuration, it is possible to provide a program for causing one or more processors to execute the above-described lighting control method. [Explanation of symbols]

[0175] 1, 1B, 1C, 1D, 1E, 1F Lighting fixtures 2A,2B,2C light source 3,3B,3C,3D,3E,3F Lighting control device 34, 34B, 34C, 34D, 34E, 34F Signal processing section 35A, 35B, 35C Control section M1, P1 First control signal (control signal) N1 Second control signal (control signal) m1, n1, p1 control values T1 Lower Limit

Claims

1. A lighting control device that controls illumination light including a plurality of lights emitted from a plurality of light sources and having different light colors, a signal processing unit that generates a plurality of control signals corresponding to the plurality of light sources, based on an instruction signal that indicates a dimming rate of the illumination light and a dimming ratio of the plurality of light sources, for controlling a current flowing through the corresponding light sources; a plurality of control units corresponding to the plurality of light sources and the plurality of control signals, and outputting currents according to control values ​​designated by the corresponding control signals to the corresponding light sources; A lower limit value for the control value of the corresponding control signal is set in each of the plurality of control units, and when the control value of the corresponding control signal is equal to or lower than the lower limit value, each of the plurality of control units stops outputting the current to the corresponding light source; when the control value is below the lower limit value in all of the generated control signals, the signal processing unit changes the control value in at least one of the multiple control signals to a value equal to or greater than the lower limit value; The signal processing unit outputs the control signal in which the control value has been changed to the value equal to or greater than the lower limit value, and the control signal in which the control value has not been changed, to a corresponding control unit among the plurality of control units. Lighting control device.

2. the plurality of control signals include a first number of first control signals having the control value with a decreasing trend and a second number of second control signals having the control value with an increasing trend; the signal processing unit changes the control value in at least one first control signal among the first number of first control signals generated to the value equal to or greater than the lower limit value from when the control value in all of the generated plurality of control signals falls below the lower limit value until the control value in at least one second control signal among the second number of second control signals generated is equal to or greater than the lower limit value; The signal processing unit outputs the first control signal, the control value of which has been changed to the value equal to or greater than the lower limit value, and the first control signal and the second control signal, the control value of which has not been changed, to a corresponding control unit among the plurality of control units. The lighting control device according to claim 1 .

3. the plurality of control signals include a first number of first control signals having the control value with a decreasing trend and a second number of second control signals having the control value with an increasing trend; the signal processing unit changes the control value in at least one second control signal among the second number of second control signals generated to a value equal to or greater than the lower limit value from when the control value in all of the generated plurality of control signals falls below the lower limit value until the control value in at least one second control signal among the second number of second control signals generated becomes equal to or greater than the lower limit value; The signal processing unit outputs the second control signal, in which the control value is changed to the value equal to or greater than the lower limit value, and the first control signal and the second control signal, in which the control value is not changed, to a corresponding control unit among the plurality of control units. The lighting control device according to claim 1 .

4. the plurality of control signals include a first number of first control signals having the control value with a decreasing trend and a second number of second control signals having the control value with an increasing trend; the signal processing unit changes the control value in at least one first control signal among the first number of first control signals generated to a first value that is equal to or greater than the lower limit value from a time when the control value in all of the plurality of generated control signals falls below the lower limit value until the control value in at least one second control signal among the second number of generated second control signals becomes equal to or greater than the lower limit value, and changes the control value in at least one second control signal among the second number of generated second control signals to a second value that is equal to or greater than the lower limit value, The signal processing unit outputs the first control signal and the second control signal, in which the control value has been changed to the value equal to or greater than the lower limit value, and the first control signal and the second control signal, in which the control value has not been changed, to a corresponding control unit among the plurality of control units. The lighting control device according to claim 1 .

5. The lower limit values ​​set in the plurality of control units include values ​​different from each other. The lighting control device according to any one of claims 1 to 4.

6. The plurality of light sources; The lighting control device according to any one of claims 1 to 4, Lighting fixtures.

7. A lighting control method for controlling lighting including a plurality of lights emitted from a plurality of light sources and having different light colors, comprising: a signal processing step of generating a plurality of control signals corresponding to the plurality of light sources, the control signals being for controlling currents flowing through the corresponding light sources, based on an instruction signal indicating a dimming rate of the illumination light and a dimming ratio of the plurality of light sources; a control step of causing a plurality of control units corresponding to the plurality of light sources and the plurality of control signals to output currents corresponding to the corresponding light sources in accordance with control values ​​designated by the corresponding control signals, A lower limit value for the control value of the corresponding control signal is set in each of the plurality of control units, and when the control value specified by the corresponding control signal is equal to or lower than the lower limit value, each of the plurality of control units stops outputting the current to the corresponding light source; In the signal processing step, when the control value is below the lower limit value in all of the generated control signals, the control value is changed to a value equal to or greater than the lower limit value in at least one control signal among the plurality of control signals; In the signal processing step, the control signal in which the control value has been changed to the value equal to or greater than the lower limit value and the control signal in which the control value has not been changed are output to corresponding control units among the plurality of control units. Lighting control methods.

8. A program for causing one or more processors to execute the lighting control method according to claim 7.

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