Control device and lighting device

Abstract

The control device controls a light source, the light source including a first light emitting element having a first emission color and a second light emitting element having a second emission color different from the first emission color, the control device including: an emission circuit outputting a first pulse voltage; the integrating circuit is electrically connected with the transmitting circuit, converts the first pulse voltage into triangular wave voltage and outputs the triangular wave voltage; the comparison circuit is electrically connected with the integrating circuit, compares the triangular wave voltage with a threshold voltage and outputs a second pulse voltage; an inverter electrically connected to the comparison circuit and outputting a third pulse voltage obtained by inverting the second pulse voltage; the first variable resistor is electrically connected with the comparison circuit and is used for adjusting the threshold voltage input into the comparison circuit; and a driving circuit that generates a first pulse signal input to the first light-emitting element based on the second pulse voltage, and generates a second signal input to the second light-emitting element based on the third pulse voltage.

Description

Technical Field

[0001] One embodiment of the present invention relates to a control device for controlling color mixing or dimming of a light source. In addition, one embodiment of the present invention relates to a lighting device capable of controlling color mixing or dimming of a light source. Background Art

[0002] In lighting devices, a control method for controlling dimming of lighting based on a control signal transmitted from an information terminal is known (for example, refer to Patent Document 1).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2018-37986 Summary of the Invention

[0006] Technical Problem to be Solved by the Invention

[0007] In a lighting device controlled by an information terminal, a control circuit including a microcomputer and a large-area dedicated digital-to-analog conversion circuit (DAC) is required. The microcomputer is expensive, and the manufacturing cost increases if the number of DACs increases. Therefore, a control device for controlling dimming or color mixing of a lighting device is desired to reduce the manufacturing cost.

[0008] In view of the above problems, one object of an embodiment of the present invention is to provide a control device for a light source that reduces the manufacturing cost. In addition, one object of an embodiment of the present invention is to provide a lighting device that reduces the manufacturing cost.

[0009] Technical Solution for Solving the Technical Problem

[0010] The control device according to one embodiment of the present invention is a control device for controlling a light source, the light source including a first light-emitting element having a first emission color and a second light-emitting element having a second emission color different from the first emission color, the control device including: a transmission circuit that outputs a first pulse voltage; an integration circuit electrically connected to the transmission circuit that converts the first pulse voltage into a triangular wave voltage and outputs it; a comparison circuit electrically connected to the integration circuit that compares the triangular wave voltage with a threshold voltage and outputs a second pulse voltage; an inverter electrically connected to the comparison circuit that outputs a third pulse voltage obtained by inverting the second pulse voltage; a first variable resistor electrically connected to the comparison circuit that adjusts the threshold voltage input to the comparison circuit; and a drive circuit that generates a first pulse signal input to the first light-emitting element based on the second pulse voltage, and a second signal input to the second light-emitting element based on the third pulse voltage.

[0011] A lighting device according to an embodiment of the present invention includes: a light source including a first light-emitting element and a second light-emitting element, the first light-emitting element having a first emission color and the second light-emitting element having a second emission color different from the first emission color; an optical element including a plurality of liquid crystal cells, the optical element transmitting light irradiated from the light source and controlling the light distribution; and a control device connected to the light source for controlling the first light-emitting element and the second light-emitting element, the control device including: an oscillation circuit for outputting a first pulse voltage; an integration circuit electrically connected to the oscillation circuit for converting the first pulse voltage into a triangular wave voltage and outputting it; a comparison circuit electrically connected to the integration circuit for comparing the triangular wave voltage with a threshold voltage and outputting a second pulse voltage; an inverter electrically connected to the comparison circuit and outputting a third pulse voltage obtained by inverting the second pulse voltage; a first variable resistor electrically connected to the comparison circuit for adjusting the threshold voltage input to the comparison circuit; and a drive circuit for generating a first pulse signal based on the second pulse voltage and a second pulse signal based on the third pulse voltage, the first pulse signal being input to the first light-emitting element and the second pulse signal being input to the second light-emitting element. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 FIG. is a schematic diagram showing the configuration of a lighting device according to an embodiment of the present invention.

[0013] Figure 2 FIG. is a schematic diagram showing the configuration of the light source of a lighting device according to an embodiment of the present invention.

[0014] Figure 3 FIG. is a block diagram showing the configuration of a power supply device and a second control device of a lighting device according to an embodiment of the present invention.

[0015] Figure 4 FIG. is a circuit diagram showing the circuit configuration of a part of the control device of a lighting device according to an embodiment of the present invention.

[0016] Figure 5 FIG. is a schematic diagram for explaining a first pulse signal and a second pulse signal output from a second control device of a lighting device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings and the like. However, the present invention can be implemented in various ways without departing from the gist of its technical concept, and is not limited to the content described in the following exemplary embodiments.

[0018] For the sake of clarity, compared with the actual form, the width, thickness, shape, etc. of each part in the drawings are sometimes schematically shown. After all, it is just an example, and the shape shown itself does not limit the interpretation of the present invention. In addition, in the drawings, sometimes elements having the same function as those already described in the drawings in the specification are labeled with the same reference numerals in other drawings, and repeated descriptions are omitted.

[0019] In the case of processing a certain film to form a plurality of structures, each structure may sometimes have different functions and effects. In addition, each structure may sometimes be formed on a different substrate. However, these multiple structures are derived from a film formed in the same process and having the same material. Therefore, these multiple films are defined as existing in the same layer.

[0020] When expressing the form of arranging other structures on a certain structure, when only expressed as "on", as long as there is no special explanation, it includes both the case of arranging other structures directly above and in contact with a certain structure and the case of arranging other structures further above a certain structure with another structure in between.

[0021] Refer to Figures 1 to 5 , and a lighting device 1 according to an embodiment of the present invention will be described. It should be noted that although the configuration of the lighting device 1 as an embodiment of the present invention will be described below, the embodiments of the present invention are not limited to the lighting device 1. A part of the configuration of the lighting device 1 may also constitute an embodiment of the present invention.

[0022] [1. Configuration of Lighting Device 1]

[0023] Figure 1 is a schematic diagram showing the configuration of a lighting device 1 according to an embodiment of the present invention. As Figure 1 shown, the lighting device 1 includes an optical element 10, a light source 20, a first control device 30, a power supply device 40, and a second control device 50. The first control device 30 and the second control device 50 are control devices for the optical element 10 and for the light source 20, respectively. In the lighting device 1, the light emitted from the light source 20 passes through the optical element 10 and is emitted. At this time, the light source 20 is controlled by the second control device 50 to change the light emitted from the light source 20. In addition, the optical element 10 is controlled by the first control device 30 to change the light passing through the optical element 10. Specifically, color adjustment or dimming is controlled by the second control device 50, and light distribution is controlled by the first control device 30.

[0024] [2. Configuration of Optical Element 10 and First Control Device 30]

[0025] The optical element 10 includes four liquid crystal cells 100 stacked in the z-axis direction. Although not shown, the liquid crystal cell 100 has a structure in which liquid crystal is encapsulated between two glass substrates with transparent electrodes formed in a comb shape. When a potential difference is applied between adjacent transparent electrodes on the glass substrate, the orientation of the liquid crystal molecules changes, causing a refractive index distribution to be generated in the liquid crystal. Accordingly, the transmitted light is diffused. As a result, the light distribution (shape or angle) of the light transmitted through the liquid crystal changes. In the first control device 30, a voltage signal applied to the transparent electrodes of the liquid crystal cell 100 is generated. It should be noted that although Figure 1 the optical element 10 including four liquid crystal cells 100 is shown, the number of liquid crystal cells 100 is not limited to four. The optical element 10 only needs to include at least two liquid crystal cells 100.

[0026] The first control device 30 is connected to the four liquid crystal cells 100 of the optical element 10 and controls each liquid crystal cell 100 of the optical element 10. Specifically, the first control device 30 generates a voltage signal corresponding to the light distribution. Eight adjustment knobs (volume knobs) 31 that can be rotated by the user are provided in the first control device 30. By changing the combination of the rotations of the eight adjustment knobs 31 and the respective rotation angles of the eight adjustment knobs 31, the voltage signal applied to the transparent electrodes of each liquid crystal cell 100 can be adjusted. In other words, the light distribution of the light emitted from the optical element 10 can be adjusted by the adjustment knobs 31. Although Figure 1 eight adjustment knobs 31 are shown for allocating two adjustment knobs 31 to the control of one liquid crystal cell 100, the number of adjustment knobs 31 is not limited to eight. It should be noted that the adjustment knobs 31 may also be of a sliding type instead of a rotary type.

[0027] [3. Structure of the power supply device 40]

[0028] The power supply device 40 is connected to the first control device 30 and the second control device 50 and generates a power supply voltage required to drive the first control device 30 and the second control device 50. In the power supply device 40, multiple power supply voltages may also be generated. In addition, the power supply device 40 may also include a power supply voltage that is GND (for example, 0V). It should be noted that in this specification, for convenience, in the case of GND, it is sometimes also described as generating a power supply voltage.

[0029] It should be noted that in Figure 1 one power supply device 40 is shown, but the power supply device 40 may also be divided into a power supply device that generates the power supply voltage supplied to the first control device 30 and a power supply device that generates the power supply voltage supplied to the second control device 50. In addition, the power supply device 40 may also be of a structure integrated with the first control device 30 or the second control device 50.

[0030] [Configuration of Light Source 20 and Second Control Device 50]

[0031] The light source 20 is disposed above the optical element 10 and emits light toward the optical element 10. As the light source 20, for example, light-emitting diodes (LEDs) can be used, but it is not limited thereto. The light source 20 can be any element or device that can emit light.

[0032] Refer to Figure 2 for a detailed description of the configuration of the light source 20.

[0033] Figure 2 is a schematic diagram showing the configuration of the light source 20 of the lighting device 1 according to an embodiment of the present invention. Figure 2 shows, as an example of the light source 20, a configuration using light-emitting diodes.

[0034] As Figure 2 shown, the light source 20 includes a substrate 21, a first light-emitting element 22, and a second light-emitting element 23. The first light-emitting element 22 and the second light-emitting element 23 are light-emitting diodes. A plurality of first light-emitting elements 22 and a plurality of second light-emitting elements 23 are arranged in the substrate 21. A first pulse signal generated by the second control device 50 is input to each of the plurality of first light-emitting elements 22. In addition, a second pulse signal generated by the second control device 50 is input to each of the plurality of second light-emitting elements 23. In the lighting device 1, the color mixing or dimming of the light source 20 can be controlled based on the first pulse signal and the second pulse signal. It should be noted that the first pulse signal and the second pulse signal will be described later.

[0035] The plurality of first light-emitting elements 22 and the plurality of second light-emitting elements 23 are alternately arranged one by one and form a circle. However, the arrangement of the plurality of first light-emitting elements 22 and the plurality of second light-emitting elements 23 is not limited thereto. Preferably, the plurality of first light-emitting elements 22 and the plurality of second light-emitting elements 23 are symmetrically arranged so that the light emitted from the light source 20 is uniformly incident on the optical element 10. It should be noted that the number of each of the first light-emitting element 22 and the second light-emitting element 23 is preferably plural, but it is not limited thereto. The number of each of the first light-emitting element 22 and the second light-emitting element 23 can also be one. In addition, the number of the first light-emitting elements 22 and the number of the second light-emitting elements 23 can be the same or different.

[0036] The first light-emitting element 22 has a first emission color. The second light-emitting element 23 has a second emission color different from the first emission color. For example, by combining the first light-emitting element 22 that emits blue light and the second light-emitting element 23 that emits yellow light, the light source 20 can emit white light. It is also possible to combine the first light-emitting element 22 having the first emission color and the second light-emitting element 23 having the second emission color so that light of a bulb color (color temperature 3000K), a day white color (color temperature 5000K), or a daylight color (color temperature 6500K) is emitted from the light source 20. The second light-emitting element 23 may also have a configuration in which a phosphor is provided on the first light-emitting element 22 and the first emission color is converted into the second emission color by the phosphor. The light source 20 may also have a configuration other than white light, and the first emission color and the second emission color are not particularly limited.

[0037] Although not shown, a reflector may be provided on the inner side surface of the base 21. In this case, the light emitted from the first light-emitting element 22 and the second light-emitting element 23 is reflected by the reflector and emitted from the light source 20. Therefore, the amount of light incident on the optical element 10 increases.

[0038] Return to Figure 1 , the configuration of the second control device 50 will be described. The second control device 50 is connected to the light source 20 and controls the first light-emitting element 22 and the second light-emitting element 23 of the light source 20. Specifically, the second control device 50 generates a first pulse signal input to the first light-emitting element 22 and a second pulse signal input to the second light-emitting element 23 according to color adjustment or dimming. The second control device 50 is provided with a first adjustment knob 51 and a second adjustment knob 52 that can be rotated by the user. By adjusting the rotation angle of the first adjustment knob 51, the color adjustment of the light source 20 can be controlled. In addition, by adjusting the rotation angle of the second adjustment knob 52, the dimming of the light source 20 can be controlled. It should be noted that the first adjustment knob 51 and the second adjustment knob 52 may not be rotary but sliding type.

[0039] Refer to Figure 3 and Figure 4 , the configuration of the second control device 50 will be further described in detail.

[0040] Figure 3 is a block diagram showing the configurations of the power supply device 40 and the second control device 50 of the lighting device 1 according to an embodiment of the present invention.

[0041] As Figure 3As shown, the power supply device 40 includes a first power supply 410, a second power supply 420, and a third power supply 430. In addition, the second control device 50 includes an oscillation circuit 510, an integration circuit 520, a comparison circuit 530, an inverter 540, a drive circuit 550, a first variable resistor 560, and a second variable resistor 570. The first adjustment knob 51 is connected to the first variable resistor 560. If the user rotates the first adjustment knob 51, the resistance of the first variable resistor 560 changes. In addition, the second adjustment knob 52 is connected to the second variable resistor 570. If the user rotates the second adjustment knob 52, the resistance of the second variable resistor 570 changes.

[0042] The first power supply 410 is electrically connected to the drive circuit 550 and supplies a power supply voltage for driving the drive circuit 550. The second power supply 420 is electrically connected to the oscillation circuit 510 and supplies a power supply voltage for the oscillation circuit 510 to generate a pulse voltage. The third power supply 430 is electrically connected to the first variable resistor 560 and supplies a power supply voltage for generating a threshold voltage input to the comparison circuit 530.

[0043] The oscillation circuit 510 generates and outputs a first pulse voltage. The oscillation circuit 510 is electrically connected to the integration circuit 520, and the first pulse voltage output from the oscillation circuit 510 is input to the integration circuit 520.

[0044] The integration circuit 520 converts the first pulse voltage into a triangular wave voltage and outputs it. The integration circuit 520 is electrically connected to the comparison circuit 530, and the triangular wave voltage output from the integration circuit 520 is input to the comparison circuit 530.

[0045] The comparison circuit 530 is connected to the integration circuit 520 and the first variable resistor 560. The triangular wave voltage from the integration circuit 520 and the threshold voltage from the first variable resistor 560 are input to the comparison circuit 530. The comparison circuit 530 compares the triangular wave voltage with the threshold voltage and generates a second pulse voltage. Specifically, the comparison circuit 530 generates a second pulse voltage that conducts when the triangular wave voltage is above the threshold voltage and disconnects when the triangular wave voltage is less than the threshold voltage. The threshold voltage changes according to the resistance of the first variable resistor 560. Therefore, by adjusting the resistance of the first variable resistor 560, the conduction period of the second pulse voltage can be controlled. That is, the second pulse voltage is a PWM (Pulse Width Modulation) voltage whose conduction period and disconnection period are controlled. The duty ratio of the conduction period in the second pulse voltage is determined by the threshold voltage.

[0046] The second pulse voltage is output from the comparison circuit 530, and the third pulse voltage obtained by inverting the phase of the second pulse voltage through the inverter 540. The conduction period in the third pulse voltage corresponds to the non-conduction period of the second pulse voltage. The comparison circuit 530 and the inverter 540 are electrically connected to the drive circuit 550, and the second pulse voltage and the third pulse voltage are input to the drive circuit 550.

[0047] The drive circuit 550 is electrically connected to the comparison circuit 530, the inverter 540, and the second variable resistor 570. The second pulse voltage and the third pulse voltage are respectively converted into a first pulse signal S1 for driving the first light-emitting element 22 and a second pulse signal S2 for driving the second light-emitting element 23 through the drive circuit 550. Although the first pulse signal S1 and the second pulse signal S2 are respectively generated based on the second pulse voltage and the third pulse voltage, at this time, the amplitudes of the first pulse signal S1 and the second pulse signal S2 change according to the resistance of the second variable resistor 570. That is, by adjusting the resistance of the second variable resistor 570, the amplitudes of the first pulse signal S1 and the second pulse signal S2 can be controlled.

[0048] The first light-emitting element 22 input with the first pulse signal S1 can emit light only during the conduction period corresponding to the duty ratio. The same applies to the second light-emitting element 23 input with the second pulse signal S2. That is, the light source 20 including the first light-emitting element 22 and the second light-emitting element 23 is controlled by PWM driving. If the duty ratio is changed, the light-emitting periods of the first light-emitting color of the first light-emitting element 22 and the second light-emitting color of the second light-emitting element 23 change, and the color of the light emitted from the light source 20 changes. In addition, if the amplitudes of the first pulse signal S1 and the second pulse signal S2 are changed, the brightnesses of the first light-emitting element 22 and the second light-emitting element 23 change. Thus, in the second control device 50, the first pulse signal S1 and the second pulse signal S2 for controlling the color mixing and dimming of the light source 20 can be generated.

[0049] Refer to Figure 4 , the circuit configuration of the second control circuit 500 will be described, but mainly the oscillation circuit 510, the integration circuit 520, and the comparison circuit 530 will be described below. In the second control circuit 500, by applying a circuit configuration using an operational amplifier, expensive components such as a microcomputer or a DAC are not required. Therefore, the manufacturing cost of the lighting device 1 can be reduced.

[0050] Figure 4 is a circuit diagram showing a part of the circuit configuration of the second control device 50 of the lighting device 1 according to an embodiment of the present invention. It should be noted that Figure 4This is an example of the circuit configuration of the second control circuit 500, and the circuit configuration of the second control circuit 500 is not limited thereto. In addition, in Figure 4 connections of power supplies and the like that can be understood by those skilled in the art are omitted.

[0051] The oscillation circuit 510 includes a first operational amplifier OPA1. In the first operational amplifier OPA1, the inverting input terminal (-) is connected to the output terminal via a resistor element R1. In addition, the inverting input terminal (-) is connected to a capacitor element C1. On the other hand, the non-inverting input terminal (+) is connected to the output terminal via a resistor element R2. In addition, the non-inverting input terminal (+) is connected to the second power supply 420 via a resistor element R3 and is connected to GND via a resistor element R4. The resistor element R1 and the resistor element R2 function as feedback resistors. The resistor element R3 and the resistor element R4 function as voltage dividing resistors. According to such a circuit configuration, if a HIGH voltage is output from the output terminal of the first operational amplifier OPA1, the capacitor element C1 is charged, and if a LOW voltage is output from the output terminal of the first operational amplifier OPA1, the capacitor element C1 is discharged. That is, by inputting the varying voltage of the capacitor element C1 to the inverting input terminal (-) and comparing it with the voltage input to the non-inverting input terminal (+), a first pulse voltage that repeats HIGH voltage and LOW voltage is output from the output terminal.

[0052] The integration circuit 520 includes a second operational amplifier OPA2. In the second operational amplifier OPA2, the inverting input terminal (-) is connected to the output terminal via a capacitor element C2. In addition, the inverting input terminal (-) is connected to the output terminal of the first operational amplifier OPA1, and the first pulse voltage is input to the inverting input terminal (-). On the other hand, the non-inverting input terminal (+) is connected to the second power supply 420 via a resistor element R5 and is connected to GND via a resistor element R6. The capacitor element C2 functions as a feedback resistor. The resistor element R5 and the resistor element R6 function as voltage dividing resistors. According to such a circuit configuration, if a HIGH voltage is input to the inverting input terminal (-), charging is performed from the inverting input terminal (-) side with a constant current through the capacitor element C2, and the voltage output from the output terminal of the second operational amplifier OPA2 linearly decreases. On the other hand, if a LOW voltage is input to the inverting input terminal (-), conversely, the voltage output from the output terminal of the second operational amplifier OPA2 linearly increases. Therefore, if the first pulse voltage is input to the inverting input terminal (-) of the second operational amplifier OPA2, a triangular wave voltage that repeats linear increase and decrease of the voltage is output from the output terminal.

[0053] The comparison circuit 530 includes a third operational amplifier OPA3. In the third operational amplifier OPA3, the inverting input terminal (-) is connected to the output terminal of the second operational amplifier OPA2, and a triangular wave voltage is input to the inverting input terminal (-). On the other hand, the non-inverting input terminal (+) is connected to the first variable resistor 560. The third power supply 430 is connected to the first variable resistor 560. Therefore, a threshold voltage corresponding to the resistance of the first variable resistor 560 is input to the non-inverting input terminal (+). In the third operational amplifier OPA3, the triangular wave voltage input to the inverting input terminal (-) is compared with the threshold voltage input to the non-inverting input terminal (+). If the triangular wave voltage is equal to or higher than the threshold voltage, a HIGH voltage is output from the output terminal. If the triangular wave voltage is less than the threshold voltage, a LOW voltage is output from the output terminal. That is, a second pulse voltage that repeats HIGH voltage and LOW voltage is output from the output terminal of the third operational amplifier OPA3. The period of the HIGH voltage is determined by the threshold voltage. Specifically, if the threshold voltage becomes higher, the period of the HIGH voltage becomes shorter, and if the threshold voltage becomes lower, the period of the HIGH voltage becomes longer. Therefore, the second pulse voltage is a PWM voltage whose duty ratio can be adjusted by the threshold voltage.

[0054] The first variable resistor 560 includes, for example, a resistor element R7 and a variable resistor element Rv. The resistor element R7 and the variable resistor element Rv are connected in series. The resistor element R7 functions as a fixed resistor that determines the range of the threshold voltage output via the first variable resistor 560. For example, even when the power supply voltage generated by the third power supply 430 is +15V, by connecting the resistor element R7 to the variable resistor element Rv, the range of the threshold voltage output via the variable resistor element Rv (such as 0 to +10V, etc.) can be adjusted.

[0055] The second pulse voltage output from the output terminal of the third operational amplifier OPA3 of the comparison circuit 530 is phase-inverted by the inverter 540. The comparison circuit 530 and the inverter 540 are connected to the drive circuit 550. As a result, the second pulse voltage and a third pulse voltage obtained by inverting the phase of the second pulse voltage are input to the drive circuit 550. The period of the HIGH voltage in the third pulse voltage corresponds to the period of the LOW voltage in the second pulse voltage. Therefore, the third pulse voltage is also a PWM voltage whose duty ratio is adjusted according to the threshold voltage.

[0056] Figure 5 It is a schematic diagram for explaining the first pulse signal S1 and the second pulse signal S2 output from the second control device 50 of the lighting device according to an embodiment of the present invention. Specifically, Figure 5Shown are a second pulse voltage P2 (duty ratio p%) and a third pulse voltage P3 (duty ratio q%) with adjusted duty ratios of the input drive circuit 550, and a first pulse signal S1 and a second pulse signal S2 output from the drive circuit 550.

[0057] In the drive circuit 550, the second pulse voltage P2 and the third pulse voltage P3 are respectively converted into signals for driving the first light-emitting element 22 and the second light-emitting element 23. The first pulse signal S1 for driving the first light-emitting element 22 is generated based on the second pulse voltage P2. Therefore, the first pulse signal S1 has the same duty ratio p% as the second pulse voltage P2. The second pulse signal S2 for driving the second light-emitting element 23 is generated based on the third pulse voltage P3. Therefore, the second pulse signal S2 has the same duty ratio q% as the third pulse voltage P3. That is to say, the light source 20 including the first light-emitting element 22 and the second light-emitting element 23 is controlled by PWM driving.

[0058] In the light source 20, during the period of the duty ratio p% in one cycle, the first light-emitting element 22 is driven to emit light having a first emission color. In addition, during the period of the duty ratio q% in one cycle, the second light-emitting element 23 is driven to emit light having a second emission color. By adjusting each duty ratio, the emission period of the first emission color and the emission period of the second emission color can be changed, and thus the color of the light emitted from the light source 20 changes. As described above, each duty ratio is determined by the resistance of the first variable resistor 560. Therefore, in the lighting device 1, the resistance of the first variable resistor 560 can be adjusted to change the color of the light emitted from the light source 20.

[0059] In addition, the second variable resistor 570 is electrically connected to the drive circuit 550. In the drive circuit 550, the amplitudes of the first pulse signal S1 and the second pulse signal S2 change according to the resistance of the second variable resistor 570. If the amplitude of the first pulse signal S1 becomes larger, the brightness of the first light-emitting element 22 input with the first pulse becomes larger. The same applies to the second light-emitting element 23 input with the second pulse signal S2. Therefore, in the lighting device 1, the resistance of the second variable resistor 570 can be adjusted to change the brightness of the light emitted from the light source 20.

[0060] Therefore, in the lighting device 1, the color adjustment of the light source 20 can be controlled by adjusting the resistance of the first variable resistor 560 of the second control device 50, and the dimming of the light source 20 can be controlled by adjusting the resistance of the second variable resistor 570 of the second control device 50.

[0061] As described above, according to the lighting device 1 according to the present embodiment, it is possible to control the color rendering or dimming of the light source 20 without using expensive components such as a microcomputer and a DAC. Therefore, in the lighting device 1, the manufacturing cost can be reduced.

[0062] It should be understood that within the scope of the concept of the present invention, those skilled in the art can conceive of various variations and modifications, and these variations and modifications also belong to the scope of the present invention. For example, with regard to the technical solutions obtained by appropriately adding, deleting, or designing changes to the components of the above-described embodiments by those skilled in the art, or the technical solutions obtained by adding, omitting, or changing conditions to the processes, as long as they possess the gist of the present invention, they are included in the scope of the present invention.

[0063] In addition, it should be understood that with regard to other effects brought about by the embodiments, the effects clearly described in this specification, or the effects that can be appropriately conceived by those skilled in the art are of course brought about by the present invention.

[0064] Description of Reference Numerals

[0065] 1: Lighting device; 10: Optical element; 20: Light source; 21: Substrate; 22: First light-emitting element; 23: Second light-emitting element; 30: First control device; 31: Adjustment knob; 40: Power supply device; 50: Second control device; 51: First adjustment knob; 52: Second adjustment knob; 100: Liquid crystal cell; 410: First power supply; 420: Second power supply; 430: Third power supply; 500: Second control circuit; 510: Oscillation circuit; 520: Integration circuit; 530: Comparison circuit; 540: Inverter; 550: Drive circuit; 560: First variable resistor; 570: Second variable resistor; C1, C2: Capacitor element; OPA1: First operational amplifier; OPA2: Second operational amplifier; OPA3: Third operational amplifier; R1, R2, R3, R4, R5, R6, R7: Resistor element; Rv: Variable resistor element.

Claims

1. A control device controls a light source, which includes a first light-emitting element having a first emission color and a second light-emitting element having a second emission color different from the first emission color. The control device includes: A transmitting circuit outputs a first pulse voltage. An integrating circuit is electrically connected to the transmitting circuit, converts the first pulse voltage into a triangular-wave voltage and outputs it. A comparing circuit is electrically connected to the integrating circuit, compares the triangular-wave voltage with a threshold voltage and outputs a second pulse voltage. An inverter is electrically connected to the comparing circuit and outputs a third pulse voltage obtained by inverting the second pulse voltage. A first variable resistor is electrically connected to the comparing circuit and adjusts the threshold voltage input to the comparing circuit. And A driving circuit generates a first pulse signal input to the first light-emitting element based on the second pulse voltage, and generates a second pulse signal input to the second light-emitting element based on the third pulse voltage.

2. The control device according to claim 1, wherein The control device further includes a second variable resistor, which is electrically connected to the driving circuit and adjusts the amplitudes of the first pulse signal and the second pulse signal respectively.

3. The control device according to claim 1 or 2, wherein Each of the transmitting circuit, the integrating circuit and the comparing circuit includes an operational amplifier.

4. The control device according to claim 3, wherein The first variable resistor is connected to the non-inverting input terminal of the operational amplifier included in the comparing circuit.

5. The control device according to claim 1 or 2, wherein Each of the first light-emitting element and the second light-emitting element is a light-emitting diode.

6. An illumination device includes: A light source includes a first light-emitting element and a second light-emitting element. The first light-emitting element has a first emission color, and the second light-emitting element has a second emission color different from the first emission color. An optical element includes a plurality of liquid crystal cells. The optical element transmits the light irradiated from the light source and controls the light distribution. And A control device is connected to the light source and controls the first light-emitting element and the second light-emitting element. The control device includes: An oscillation circuit outputs a first pulse voltage. An integrating circuit is electrically connected to the oscillation circuit, converts the first pulse voltage into a triangular-wave voltage and outputs it. A comparing circuit is electrically connected to the integrating circuit, compares the triangular-wave voltage with a threshold voltage and outputs a second pulse voltage. An inverter is electrically connected to the comparing circuit and outputs a third pulse voltage obtained by inverting the second pulse voltage. A first variable resistor is electrically connected to the comparing circuit and adjusts the threshold voltage input to the comparing circuit; and A driving circuit generates a first pulse signal based on the second pulse voltage and generates a second pulse signal based on the third pulse voltage. The first pulse signal is input to the first light-emitting element. The second pulse signal is input to the second light-emitting element.

7. The illumination device according to claim 6, wherein The control device further includes a second variable resistor, which is electrically connected to the drive circuit to adjust the amplitudes of the first pulse signal and the second pulse signal respectively.

8. The lighting device according to claim 6 or 7, wherein the oscillation circuit, the integration circuit, and the comparison circuit each include an operational amplifier.

9. The lighting device according to claim 8, wherein the first variable resistor is connected to the non-inverting input terminal of the operational amplifier included in the comparison circuit.

10. The lighting device according to claim 6 or 7, wherein the first light-emitting element and the second light-emitting element are each a light-emitting diode.

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