JP5441943B2 - Light source lighting device, lighting fixture, and dimming system - Google Patents

Description

  The present invention relates to a light source lighting device, a lighting fixture, and a dimming system that use an LED (Light Emitting Diode), an EL (Electro Luminescence), or the like as a light source.

  2. Description of the Related Art Conventionally, in a lighting device having a plurality of LED elements having different emission colors or color temperatures, a technique for arbitrarily setting a mixed color light and a light amount by adjusting a current value of a current supplied to each color LED is known ( For example, see Patent Document 1). In addition, there is a technique that can adjust the color temperature and the amount of light with one dimming signal in a lighting device having a plurality of similar LED elements (see, for example, Patent Document 2).

JP 2006-40872 A JP 2010-176984 A

  For example, in the illuminating device of Patent Document 1, when adjusting the light amount of the LED of each emission color, a dimming signal instructing the light amount of each LED is input from the dimming controller to the LED lighting device to adjust the light amount of the LED. . At this time, an analog signal (for example, a PWM (pulse width modulation) signal or a DC (direct current) voltage signal) is generally used as the dimming signal. Conventionally, the number of such dimming signals is required in accordance with the number of emission colors. For example, when a PWM signal is used as the dimming signal, and two types of LEDs having different emission colors are used, the PWM signal is It was necessary for 2ch (channel). For this reason, the number of signal lines connecting the dimming controller and the LED lighting device and the number of dimming signal receiving terminals of the LED lighting device are required in accordance with the number of signals. Therefore, for example, in the illumination device of Patent Document 2, the light amount of the LED of each emission color is determined so that the color temperature and the light amount increase or decrease in association with only one dimming signal (PWM signal). However, there has been a problem that the operation of adjusting the light quantity of each light emitting LED independently cannot be performed from the dimming controller.

  An object of the present invention is to independently control the light amounts of a plurality of light sources having different emission colors, for example, with a simple circuit configuration.

A light source lighting device according to an aspect of the present invention includes:
A first constant current power supply unit that outputs a current to the first light source and lights the first light source with a light output corresponding to a current value of the current;
A second constant current power supply unit for outputting a current to the second light source and lighting the second light source with a light output corresponding to a current value of the current;
From the dimming signal output device that outputs the dimming signal by controlling the duty ratio and period of the dimming signal for dimming both the first light source and the second light source, A dimming signal measuring unit that inputs and measures the duty ratio and period of the input dimming signal;
The first constant current power supply unit is controlled to output a current having a current value corresponding to the duty ratio of the dimming signal measured by the dimming signal measurement unit from the first constant current power supply unit, and the second A control unit that controls the constant current power supply unit to output a current having a current value corresponding to a cycle of the dimming signal measured by the dimming signal measurement unit from the second constant current power supply unit.

  In one aspect of the present invention, in the light source lighting device, the control unit outputs a current having a current value corresponding to the duty ratio of the dimming signal from the first constant current power source unit that lights the first light source, and adjusts the current. A current having a current value corresponding to the period of the optical signal is output from the second constant current power supply unit that turns on the second light source. For this reason, it is possible to independently control the light amounts of a plurality of light sources having different emission colors with a simple circuit configuration.

(A) Side view sectional drawing of the lighting fixture which concerns on Embodiment 1, (b) The circuit diagram of the light source lighting device. (A) The figure which shows an example of the waveform of a dimming signal which concerns on Embodiment 1, (b) The figure which shows an example of a dimming controller, (c) The graph which shows the relationship between the frequency of a dimming signal, and LED current, (D) The graph which shows the relationship between the period of a light control signal, and LED current. (A) The target current value setting table corresponding to the cycle of the dimming signal according to the first embodiment, and (b) The target current value setting table corresponding to the duty ratio of the dimming signal. (A) The graph which shows the relationship between the duty ratio of a light control signal and LED current which concerns on Embodiment 1, (b) The graph which shows the relationship between LED current and light output. (A) The graph which shows the relationship between the period of a light control signal and optical output which concerns on Embodiment 1, (b) The graph which shows the relationship between the duty ratio of a light control signal, and an optical output. FIG. 4 is a circuit diagram of a light source lighting device according to Embodiment 2. (A) The figure which shows the 1st example of a structure of the light control signal selection part which concerns on Embodiment 2, (b) The figure which shows the 2nd example of the structure of the light control signal selection part, (c) The light control signal selection part The figure which shows the 3rd example of a structure of.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
Fig.1 (a) is side sectional drawing of the lighting fixture 10 which concerns on this Embodiment.

  In FIG. 1A, a lighting fixture 10 includes a fixture body 11, a power line 12, a connector 13, an LED 14a (first light source) and an LED 14b (second light source), a substrate 15, a wiring 16, and a light source. And a lighting device 20.

  A light source lighting device 20 is housed inside the instrument body 11 and connected to an external commercial power source via a power line 12 and a connector 13. A substrate 15 on which LEDs 14a and 14b (LED packages) having different color temperatures are mounted is mounted inside the instrument body 11 so that the light emitting surfaces of the LEDs 14a and 14b face the opening of the instrument body 11, and the light source is turned on by the wiring 16. Connected to device 20. The LEDs 14a and 14b are arranged in a line in a substantially straight line so that four LEDs are alternately arranged, that is, LEDs having the same color temperature are not adjacent to each other. Although not shown, the light source lighting device 20 is provided with a dimming signal input terminal, and a dimming signal line from a dimming controller described later is connected to the dimming signal input terminal.

  In the present embodiment, the number of LEDs 14a and 14b is not limited to four, but may be three or less, or five or more. Further, the arrangement of the LEDs 14a and 14b may not be alternate. For example, two LEDs 14a and 14b may be arranged in order. The arrangement of the LEDs 14a and 14b is not limited to a linear shape, and may be a ring shape, for example. Moreover, LED14a, 14b may be arrange | positioned in multiple rows instead of 1 row. Moreover, EL etc. may be used instead of LED14a, 14b as a light source.

  FIG. 1B is a circuit diagram of the light source lighting device 20.

  The light source lighting device 20 is a device that receives power supplied from the commercial AC power source 21 and lights the LEDs 14a and 14b. The light source lighting device 20 constitutes a dimming system for dimming the LEDs 14a and 14b together with the dimming controller 32 (dimming signal output device).

  In FIG. 1B, the light source lighting device 20 includes a rectifier circuit 22, a power factor improvement circuit 23 composed of a boost chopper circuit, a control IC 25, and a first step-down chopper circuit connected to the subsequent stage of the power factor improvement circuit 23. 26a (first constant current power supply unit), a second step-down chopper circuit 26b (second constant current power supply unit), and a control unit 29. The rectifier circuit 22 is configured as a diode bridge, for example. The power factor correction circuit 23 includes a switching element 24 and the like. The first step-down chopper circuit 26a includes a switching element 27a, an LED current detection resistor 28a, and the like. The second step-down chopper circuit 26b includes a switching element 27b, an LED current detection resistor 28b, and the like. The control unit 29 includes a microcomputer 30 (microcomputer) (a dimming signal measurement unit) and a step-down chopper control unit 31.

  The rectifier circuit 22 and the power factor correction circuit 23 constitute an AC-DC converter that converts the AC voltage of the commercial AC power supply 21 into a DC voltage. The rectifier circuit 22 performs full-wave rectification on the AC voltage supplied from the commercial AC power supply 21 and outputs a pulsating voltage. The power factor improving circuit 23 is provided for the purpose of improving the power factor by driving and controlling the switching element 24 by the control IC 25, thereby controlling the waveform of the input current in a sine wave shape. The power factor correction circuit 23 boosts and smoothes the pulsating voltage output from the rectifier circuit 22 and outputs a constant DC voltage. If the power factor is not improved, the AC-DC converter may have a circuit configuration other than the configuration including the rectifier circuit 22 and the power factor correction circuit 23 as long as the circuit configuration generates a DC voltage. For example, a capacitor input type rectifier circuit may be used. In this case, the first step-down chopper circuit 26a and the second step-down chopper circuit 26b are connected to the subsequent stage of the capacitor input type rectifier circuit to share the capacitor input type rectifier circuit.

  LEDs 14a and 14b having different color temperatures are connected to the first step-down chopper circuit 26a and the second step-down chopper circuit 26b. For example, the LED 14a having a color temperature of 3000K (Kelvin) is connected to the first step-down chopper circuit 26a, and the LED 14b having a color temperature of 5000K is connected to the second step-down chopper circuit 26b. The first step-down chopper circuit 26a and the second step-down chopper circuit 26b supply current to the LEDs 14a and 14b to light the LEDs 14a and 14b. As a result, light having a color temperature of 3000K and light having a color temperature of 5000K can be mixed to obtain mixed color light having an intermediate color temperature. In the first step-down chopper circuit 26a and the second step-down chopper circuit 26b, the switching elements 27a and 27b are driven and controlled by the step-down chopper control unit 31 in the control unit 29, and thereby the current value of the current supplied to the LEDs 14a and 14b. And the ratio of the quantity of light of both can be adjusted. Therefore, the color temperature of the entire LEDs 14a and 14b can be adjusted to an arbitrary color temperature between 3000 and 5000K.

  The color temperature of the LEDs 14a and 14b may be a combination other than the combination of 3000K and 5000K. The LEDs 14a and 14b may be other types of light sources. For example, ELs having different color temperatures may be connected to the first step-down chopper circuit 26a and the second step-down chopper circuit 26b as light sources. The first step-down chopper circuit 26a and the second step-down chopper circuit 26b may be other types of circuits, flyback converters, or the like as long as they can supply current to the LEDs 14a and 14b.

  The dimming controller 32 is a device that is provided outside the light source lighting device 20 and has a user interface for the user to arbitrarily set the color temperature and dimming rate of the luminaire 10. The dimming controller 32 is mounted as, for example, a slide volume provided on a wall, a remote controller, or the like. The dimming controller 32 outputs a dimming signal to the light source lighting device 20 in order to adjust the color temperature and dimming rate of the lighting fixture 10 to those set by the user. The dimming signal is a PWM signal that specifies the current value of the current supplied to the LEDs 14a and 14b, that is, the light output of the LEDs 14a and 14b. The dimming signal is input to the control unit 29 and decoded by the microcomputer 30 provided in the control unit 29. When the microcomputer 30 determines the current value of the current to be supplied to the LEDs 14a and 14b from the dimming signal, the microcomputer 30 notifies the step-down chopper control unit 31 of the target current value (command value) of the LED current. The step-down chopper control unit 31 supplies the current of the target current value notified from the microcomputer 30 to the LEDs 14a and 14b from the first step-down chopper circuit 26a and the second step-down chopper circuit 26b.

  Hereinafter, the operation of the light source lighting device 20 will be described.

  When the power is turned on from the commercial AC power supply 21 via the rectifier circuit 22, the power factor correction circuit 23, the first step-down chopper circuit 26a, and the second step-down chopper circuit 26b start to operate, and current is supplied to the LEDs 14a and 14b. Supplied. At this time, the current value of the current supplied to the LEDs 14 a and 14 b is set according to the dimming signal output from the dimming controller 32. As described above, in order to be able to arbitrarily set the color temperature of the luminaire 10 between 3000 and 5000K, it is necessary to independently control the light outputs of the LEDs 14a and 14b. Therefore, the dimming signal must carry both information for setting the target current value of the LED 14a and information for setting the target current value of the LED 14b. Therefore, in this embodiment, the target current value of the LED 14a is assigned to the duty ratio of one PWM signal, and the target current value of the LED 14b is assigned to the cycle. Thereby, the dimming signal is only one PWM signal, and information (information for setting the target current value) for controlling the light output of each of the LEDs 14a and 14b can be carried.

  Fig.2 (a) is a figure which shows an example of the waveform of a light control signal.

  The dimming signal input from the dimming controller 32 to the control unit 29 is analyzed by the microcomputer 30. As shown in FIG. 2A, the microcomputer 30 measures a period A from the rising edge to the next falling edge of the input dimming signal and a period B from the rising edge to the next rising edge. . From period B, the cycle of the input dimming signal is obtained. Further, when A / B × 100 is calculated from the period A and the period B, the duty ratio of the input dimming signal is obtained. The microcomputer 30 determines a target current value of the output current of the first step-down chopper circuit 26a and the output current of the second step-down chopper circuit 26b from the cycle and duty ratio of the dimming signal. When the target current value is determined, a setting signal for the target current value is output from the microcomputer 30 and input to the step-down chopper control unit 31. The step-down chopper controller 31 detects the current value of the current flowing through the LEDs 14a and 14b from the LED current detection resistors 28a and 28b, compares the detected current value with the target current value, and determines the current value of the LEDs 14a and 14b. The switching elements 27a and 27b are controlled so as to approach the target current value.

  When the dimming signal output from the dimming controller 32 is a signal with a duty ratio of 100% (predetermined duty ratio), the microcomputer 30 recognizes this as a turn-off signal, and the first step-down chopper circuit 26a and the second step-down chopper circuit 26a. The operation of the step-down chopper circuit 26b is stopped, and the LEDs 14a and 14b are turned off. Thus, the LEDs 14a and 14b can be turned off from the dimming controller 32 without shutting off the commercial AC power supply 21. When the microcomputer 30 determines that the dimming signal is not input from the dimming controller 32, the microcomputer 30 causes the first step-down chopper circuit 26a and the second step-down chopper circuit 26b to output the current of the maximum output current value, and the LEDs 14a, 14b. Turn on all lights. Thereby, even if the dimming controller 32 is not connected, the light source lighting device 20 operates to light the LEDs 14a and 14b with the maximum light amount. For this reason, the light source lighting device 20 can also be used for a lighting fixture in which the color temperature is fixed and light control is not performed.

  The microcomputer 30 may recognize the dimming signal as the extinguishing signal when the cycle of the dimming signal output from the dimming controller 32 is a predetermined cycle.

  As described above, in the present embodiment, the target current value of the current supplied to each of the LEDs 14a and 14b can be set independently with only one PWM signal, and further, the extinction control and the all-light illumination control are possible. Become. Therefore, the circuit configuration of the control unit 29 of the light source lighting device 20 can be simplified, and the number of signal lines connecting the light control controller 32 to the light source lighting device 20 can be reduced. As a result, the apparatus can be reduced in size and cost.

  FIG. 2B is a diagram illustrating an example of the dimming controller 32.

  In the example of FIG. 2B, the dimming controller 32 has two slide volumes 32a and 32b as user interfaces. The sliding volume 32a corresponds to the 3000K LED 14a, and the sliding volume 32b corresponds to the 5000K LED 14b. If the volume displayed as 3000 K is slid, the duty ratio of the dimming signal output from the dimming controller 32 can be changed to change the current value of the current supplied to the LED 14 a. If the volume labeled 5000K is slid, the current value of the current supplied to the LED 14b can be changed by changing the period of the dimming signal.

  The dimming controller 32 may include a dial, a remote controller, a push button, and the like corresponding to the LEDs 14a and 14b, instead of the slide type volumes 32a and 32b as described above. For example, the dimming controller 32 assigns brightness to the sliding volume 32a, assigns a color temperature to the sliding volume 32b, and slides the sliding volume 32a so that the color temperature is fixed and only the brightness changes. A PWM signal having a preset period and duty ratio is output to 32, and if the slide type volume 32b is slid, the brightness and brightness are fixed, and only the color temperature is changed. The PWM signal may be output.

  FIG. 2C is a graph showing the relationship between the frequency of the dimming signal and the LED current.

  In order to perform control so that the light output changes linearly according to the change of the dimming signal, as shown in FIG. 2C, the output of the second step-down chopper circuit 26b with respect to the frequency of the dimming signal. It is conceivable to assign the target current value of the current in a relationship that is a linear function.

The generation of the PWM signal output as the dimming signal from the dimming controller 32 can be performed by a microcomputer (not shown) inside the dimming controller 32 as in the general method. If it is assumed that the microcomputer of the dimming controller 32 includes an 8-bit counter (timer) and this counter is used as a cycle counter for setting the cycle of the PWM signal, for example, the cycle counter is 0 to 255 ( = 2 ⁸ -1). Assuming that the value of the period counter is N, the clock frequency of the period counter is fc, and the frequency of the PWM signal is fd, the frequency fd of the PWM signal is represented by fd = 1 / ((N + 1) / fc). For example, assuming that the range of the frequency fd of the PWM signal is 100 to 1000 Hz (hertz) and the count clock frequency fc is 25 kHz (kilohertz), when the frequency counter N = 249, the frequency fd = 100 Hz, and the frequency counter N = 24, The frequency fd = 1000 Hz. Therefore, the cycle counter N changes between 249 and 24, and the frequency fd of the PWM signal changes accordingly.

  Here, consider the frequency resolution of the PWM signal. When the period counter N = 249, the frequency fd = 100 Hz. In the next step, the period counter N = 248, so the frequency fd = 100.4 Hz. The differential frequency at this time, that is, the resolution is 0.4 Hz. On the other hand, when the cycle counter N = 25, the frequency fd = 961.5 Hz, and in the next step, the cycle counter N = 24, so the frequency fd = 1000 Hz. The differential frequency at this time, that is, the resolution is 38.5 Hz. Therefore, as shown in FIG. 2 (c), when the target current value of the output current of the second step-down chopper circuit 26b is assigned to the frequency fd of the PWM signal in a relationship that is a linear function, the frequency fd increases. The frequency resolution of the PWM signal that can be output from the dimming controller 32 is lowered, and accordingly, the minimum adjustment width of the output current of the second step-down chopper circuit 26b, that is, the output resolution of the current is also lowered. For this reason, when the frequency fd of the PWM signal is high, a phenomenon in which the light output of the LED 14b changes suddenly occurs, and smooth color temperature adjustment and dimming lighting cannot be performed.

  FIG. 2D is a graph showing the relationship between the period of the dimming signal and the LED current.

  In this embodiment, since control is performed so that the light output changes linearly according to the change of the dimming signal, as shown in FIG. 2D, the frequency of the dimming signal is not the frequency of the dimming signal. The target current value of the output current of the second step-down chopper circuit 26b is assigned to the cycle in a relationship that is a linear function.

  As described above, assuming that the 8-bit counter provided in the microcomputer of the dimming controller 32 is used as a period counter, the period counter value is N, the period counter clock frequency is fc, and the PWM signal period is td. Then, the period td of the PWM signal is represented by td = (N + 1) / fc. For example, assuming that the range of the period td of the PWM signal is 1 ms (milliseconds) (frequency fd is 1000 Hz) to 10 ms (frequency fd is 100 Hz at this time) and the count clock frequency fc is 25 kHz, the period counter N = 249, the period td = 10 ms, and the period counter N = 24, the period td = 1 ms. Therefore, the cycle counter N changes between 249 and 24, and the cycle td of the PWM signal changes accordingly.

  Here, consider the periodic resolution of the PWM signal. In the case of the cycle counter N = 249, the cycle td = 10 ms, and in the next step, the cycle counter N = 248, so the cycle td = 9.96 ms. The difference period at this time, that is, the resolution is 0.04 ms. On the other hand, when the cycle counter N = 25, the cycle td = 1.04 ms, and in the next step, the cycle counter N = 24, so the cycle td = 1 ms. The difference period at this time, that is, the resolution is 0.04 ms. Therefore, as shown in FIG. 2 (d), when the target current value of the output current of the second step-down chopper circuit 26b is assigned to the period td of the PWM signal in a relationship that is a linear function, the period td is any period. Even so, since the periodic resolution of the PWM signal that can be output from the dimming controller 32 is constant, the minimum adjustment width of the output current of the second step-down chopper circuit 26b, that is, the output resolution of the current is always constant. For this reason, a phenomenon in which the light output of the LED 14b changes suddenly does not occur, and smooth color temperature adjustment and dimming can be performed.

  FIG. 3A is a target current value setting table 40b corresponding to the cycle of the dimming signal. FIG. 3B is a target current value setting table 40a corresponding to the duty ratio of the dimming signal. FIG. 4A is a graph showing the relationship between the duty ratio of the dimming signal and the LED current.

  In the present embodiment, as a method of assigning the target current value of the output current of the second step-down chopper circuit 26b to the cycle of the dimming signal in a relation that becomes a linear function, a setting table as shown in FIG. 40 b is used by the microcomputer 30. The setting table 40b is set inside a program operating on the microcomputer 30, or stored in a storage device accessed by the program. In the setting table 40b, the target current value of the output current of the second step-down chopper circuit 26b is assigned to the cycle of the dimming signal. Here, it is assumed that the microcomputer 30 outputs the first PWM signal and the second PWM signal as two PWM signals to the step-down chopper controller 31. In the setting table 40b, the duty ratio of the second PWM signal output from the microcomputer 30 is set as the target current value. The microcomputer 30 refers to the setting table 40b and outputs the second PWM signal whose duty ratio is controlled based on the cycle of the dimming signal input from the dimming controller 32 as a setting signal for the target current value. The step-down chopper control unit 31 performs on / off control of the switching element 27b of the second step-down chopper circuit 26b in accordance with the duty ratio of the second PWM signal output from the microcomputer 30. For this reason, the current value of the current applied from the second step-down chopper circuit 26b to the LED 14b can be adjusted by changing the duty ratio of the second PWM signal output from the microcomputer 30.

  Similarly, in the present embodiment, the target current value of the output current of the first step-down chopper circuit 26a is assigned to the duty ratio of the dimming signal in a relationship that is a linear function. As the method, a setting table 40a as shown in FIG. The setting table 40a is set inside a program operating on the microcomputer 30, or is stored in a storage device accessed by the program. In the setting table 40a, the target current value of the output current of the first step-down chopper circuit 26a is assigned to the duty ratio of the dimming signal. In the setting table 40a, the duty ratio of the first PWM signal output from the microcomputer 30 is set as the target current value. The microcomputer 30 refers to the setting table 40a and outputs the first PWM signal whose duty ratio is controlled based on the duty ratio of the dimming signal input from the dimming controller 32 as a target current value setting signal. The step-down chopper control unit 31 performs on / off control of the switching element 27a of the first step-down chopper circuit 26a according to the duty ratio of the first PWM signal output from the microcomputer 30. Therefore, the current value of the current applied from the first step-down chopper circuit 26a to the LED 14a can be adjusted by changing the duty ratio of the first PWM signal output from the microcomputer 30.

  In the present embodiment, the microcomputer 30 determines the target current values of the first step-down chopper circuit 26a and the second step-down chopper circuit 26b from the setting tables 40a and 40b corresponding to the duty ratio and period of the dimming signal. The microcomputer 30 may determine the target current values of the first step-down chopper circuit 26a and the second step-down chopper circuit 26b from a mathematical formula using the duty ratio and period of the dimming signal as variables. In this embodiment, the microcomputer 30 outputs a PWM signal as a setting signal for the target current value. However, the microcomputer 30 having a D / A converter (digital / analog converter) is used to directly analog the microcomputer 30. The voltage is output as a target current value setting signal, and the step-down chopper control unit 31 switches the switching elements 27a and 27b of the first step-down chopper circuit 26a and the second step-down chopper circuit 26b according to the analog voltage signal output from the microcomputer 30. On / off control may be performed.

  As described above, in the present embodiment, the first step-down chopper circuit 26a outputs a current to the LED 14a and lights the LED 14a with a light output corresponding to the current value of the current. The second step-down chopper circuit 26b outputs a current to the LED 14b and lights the LED 14b with a light output corresponding to the current value of the current. The dimming controller 32 controls the duty ratio and cycle of the dimming signal for dimming both the LEDs 14a and 14b and outputs the dimming signal. The microcomputer 30 inputs the dimming signal from the dimming controller 32. Then, the microcomputer 30 measures the duty ratio and cycle of the input dimming signal. The control unit 29 (particularly, the step-down chopper control unit 31) controls the first step-down chopper circuit 26a so that the current of the current value corresponding to the duty ratio of the dimming signal measured by the microcomputer 30 is the first step-down chopper circuit 26a. Output from. At this time, the control unit 29 sets the first value so that the current value of the current output from the first step-down chopper circuit 26 a has a substantially linear function relationship with the duty ratio of the dimming signal measured by the microcomputer 30. The step-down chopper circuit 26a is controlled. In addition, the control unit 29 (particularly, the step-down chopper control unit 31) controls the second step-down chopper circuit 26b and supplies a current having a current value corresponding to the cycle of the dimming signal measured by the microcomputer 30 to the second step-down chopper circuit. 26b. At this time, the control unit 29 performs the second step-down step so that the current value of the current output from the second step-down chopper circuit 26b has a substantially linear function relationship with the period of the dimming signal measured by the microcomputer 30. The chopper circuit 26b is controlled.

  According to the present embodiment, since the configuration as described above is adopted, it is possible to independently control the light amounts of the LEDs 14a and 14b having different emission colors with a simple circuit configuration.

  In the present embodiment, the control unit 29 is configured such that the duty ratio of the dimming signal measured by the microcomputer 30 is a predetermined duty ratio, or the cycle of the dimming signal measured by the microcomputer 30 is predetermined. If it is a cycle, the LEDs 14a and 14b are turned off. In addition, when the dimming signal is not output from the dimming controller 32, the control unit 29 causes the first step-down chopper circuit 26a and the second step-down chopper circuit 26b to output a current having the maximum current value.

  As described above, in the present embodiment, the LEDs 14a and 14b having different color temperatures are connected to the first step-down chopper circuit 26a and the second step-down chopper circuit 26b of the light source lighting device 20, and the dimming controller 32 Since the target current value of the LEDs 14a and 14b is assigned to the duty ratio and cycle of the dimming signal and the light source lighting device 20 measures the duty ratio and cycle of the dimming signal, the dimming signal is only one PWM signal. It's okay. Therefore, the circuit configuration of the control unit 29 of the light source lighting device 20 can be simplified, and the number of signal lines connecting the light control controller 32 to the light source lighting device 20 can be reduced. As a result, the apparatus can be reduced in size and cost.

  Further, according to the present embodiment, by incorporating the light source lighting device 20 as described above into the lighting fixture 10, it is possible to configure a color temperature variable LED lighting fixture with high efficiency, small size, and low cost.

  FIG. 4B is a graph showing the relationship between LED current and light output. FIG. 5A is a graph showing the relationship between the period of the light control signal and the light output. FIG. 5B is a graph showing the relationship between the duty ratio of the dimming signal and the light output.

  In the present embodiment, the control is performed so that the light output changes linearly according to the change of the dimming signal. Therefore, the first step-down chopper circuit 26a and the second step-down chopper with respect to the duty ratio and cycle of the dimming signal. The target current value of the output current of the circuit 26b is assigned by a relationship that is a linear function. However, as shown in FIG. 4B, the relationship between the LED current and the light output is not strictly proportional. Therefore, as shown in FIGS. 5A and 5B, when it is necessary to obtain a linear relationship between the dimming signal and the optical output more strictly, the first step-down chopper circuit 26a and the second step-down chopper circuit are used. The target current value of the output current 26b may be corrected and set in advance (for example, the target current value is corrected in accordance with the relationship between the LED current and the light output shown in FIG. 4B). As a result, there is no sudden change in light output due to dimming, and smooth and linear color temperature control is possible.

  As described above, in the present embodiment, the control unit 29 includes the first step-down chopper so that the light output of the LED 14a has a substantially linear function relationship with the duty ratio of the dimming signal measured by the microcomputer 30. The circuit 26a may be controlled. Further, the control unit 29 may control the second step-down chopper circuit 26b so that the light output of the LED 14b has a substantially linear function relationship with the period of the dimming signal measured by the microcomputer 30.

  In this embodiment, the relationship between the cycle of the dimming signal and the increase / decrease direction of the duty ratio and the increase / decrease direction of the LED current shown in the graph or the like (for example, if the cycle of the dimming signal is longer, the current value of the LED current is The relationship that increases and the relationship that the current value of the LED current decreases as the duty ratio increases) is merely an example, and any relationship between the cycle of the dimming signal and the increase / decrease direction of the duty ratio and the increase / decrease direction of the LED current. The same effect can be obtained even if there is a relationship (for example, a relationship in which the current value of the LED current decreases as the period of the dimming signal increases, or a relationship in which the current value of the LED current increases as the duty ratio increases). .

Embodiment 2. FIG.
In the present embodiment, differences from the first embodiment will be mainly described.

  FIG. 6 is a circuit diagram of the light source lighting device 20 according to the present embodiment.

  In the present embodiment, the light source lighting device 20 also functions as a high output light source lighting device with a fixed color temperature.

  In FIG. 6, the light source lighting device 20 includes the same components as those of the first embodiment shown in FIG. 1B, but is implemented in that the control unit 29 includes a dimming signal selection unit 33 (selection unit). This is different from Form 1.

  In the present embodiment, similarly to the first embodiment, when the LEDs 14a and 14b having different color temperatures are connected to the first step-down chopper circuit 26a and the second step-down chopper circuit 26b, the LEDs 14a and 14b having the same color temperature are connected. 14b may be connected, and the light source lighting device 20 operates differently in each case.

  Here, in a high output LED lighting apparatus, it is necessary to use a large number of LED elements in order to obtain brightness. In the case of using a large number of LED elements, the LED element connection method may be a method of connecting LED elements in series, a method of connecting LED elements in parallel, or a method of connecting LED elements in a combination thereof.

  Due to the characteristics of LED elements, individual variations in forward voltage are very large, and when LED elements having different forward voltages are connected in parallel, LED current flows in a concentrated manner to LED elements having a small forward voltage. Therefore, current does not flow evenly to the LED elements, and the LED elements on which the current concentrates may be damaged due to heat generation. Therefore, when LED elements are connected in parallel, a measure such as connecting a current mirror circuit or a resistor for limiting the current in series with the LED elements is necessary as means for flowing current evenly through the LED elements. However, when a current mirror circuit or a resistor is inserted, a conduction loss is caused thereby, resulting in a reduction in circuit efficiency.

  If all the LED elements are connected in series, a decrease in circuit efficiency can be suppressed, and a current flows evenly through all the LED elements. However, as the number of LED elements in series increases, a voltage represented by “LED forward voltage × number of series” is required, and thus the voltage that the LED lighting device must output also increases. Therefore, the number of LED elements that can be connected in series is limited.

  In the present embodiment, LEDs 14a and 14b having the same color temperature can be connected in series to the first step-down chopper circuit 26a and the second step-down chopper circuit 26b of the light source lighting device 20 configured in the same manner as in the first embodiment. In the present embodiment, since the LEDs 14a and 14b can be connected to the first step-down chopper circuit 26a and the second step-down chopper circuit 26b, a large number of LEDs 14a and 14b can be connected. Moreover, since LED14a, 14b is connected in series, it becomes high efficiency.

  The LEDs 14a and 14b may be other types of light sources. For example, an EL having the same color temperature may be connected to the first step-down chopper circuit 26a and the second step-down chopper circuit 26b as a light source. Similarly to the first embodiment, the first step-down chopper circuit 26a and the second step-down chopper circuit 26b may be other types of circuits as long as they can supply current to the LEDs 14a and 14b, such as a flyback converter. But you can.

  When the LEDs 14a and 14b having the same color temperature are connected to the first step-down chopper circuit 26a and the second step-down chopper circuit 26b, the LEDs 14a and 14b do not have to be dimmed independently as in the first embodiment. Therefore, in the present embodiment, when the LEDs 14a and 14b having the same color temperature are connected to the first step-down chopper circuit 26a and the second step-down chopper circuit 26b, the dimming controller 32 changes only the duty ratio as the dimming signal. Outputs the PWM signal. At this time, the dimming signal selector 33 causes the microcomputer 30 of the controller 29 to recognize that the LEDs 14a and 14b having the same color temperature are connected to the first step-down chopper circuit 26a and the second step-down chopper circuit 26b. . When the microcomputer 30 recognizes that the LEDs 14a and 14b having the same color temperature are connected to the first step-down chopper circuit 26a and the second step-down chopper circuit 26b, the microcomputer 30 refers to the setting table 40a and is input from the dimming controller 32. The first PWM signal and the second PWM signal (which may be one PWM signal) whose duty ratio is controlled based on the duty ratio of the dimming signal are output as target current value setting signals. The step-down chopper controller 31 turns on / off the switching elements 27a and 27b of the first step-down chopper circuit 26a and the second step-down chopper circuit 26b according to the duty ratio of the first PWM signal and the second PWM signal output from the microcomputer 30. Control. Thereby, the current having the same current value is supplied from the first step-down chopper circuit 26a and the second step-down chopper circuit 26b to the LEDs 14a and 14b.

  When the LEDs 14a and 14b having the same color temperature are connected to the first step-down chopper circuit 26a and the second step-down chopper circuit 26b, the dimming controller 32 may output a PWM signal whose cycle only changes as the dimming signal. Good. In this case, when the microcomputer 30 recognizes that the LEDs 14a and 14b having the same color temperature are connected to the first step-down chopper circuit 26a and the second step-down chopper circuit 26b, the microcomputer 30 refers to the setting table 40b and The first PWM signal and the second PWM signal (which may be one PWM signal) whose duty ratio is controlled based on the cycle of the input dimming signal are output as target current value setting signals.

  FIG. 7A is a diagram illustrating a first example of the configuration of the dimming signal selection unit 33. FIG. 7B is a diagram illustrating a second example of the configuration of the dimming signal selection unit 33.

  The dimming signal selection unit 33 is connected to a port (terminal) of the microcomputer 30 of the control unit 29. As shown in FIG. 7A, the dimming signal selector 33 includes a pull-down resistor 34 that sets the port potential to the ground side potential with respect to the port of the microcomputer 30, and a port as shown in FIG. Any one of the pull-up resistors 35 having a potential as a power supply voltage is selectively arranged on a power supply substrate (not shown).

  When the pull-down resistor 34 is connected to the port of the microcomputer 30, the microcomputer 30 is in a state where the LEDs 14a and 14b having different color temperatures are connected to the first step-down chopper circuit 26a and the second step-down chopper circuit 26b (first mode). ). Then, similarly to the first embodiment, the microcomputer 30 measures the duty ratio and cycle of the dimming signal, refers to the setting tables 40a and 40b, and sets the target according to the duty ratio and cycle of the dimming signal. The current value is set in the first step-down chopper circuit 26a and the second step-down chopper circuit 26b via the step-down chopper control unit 31. Thereby, the microcomputer 30 dimmes the LEDs 14a and 14b independently.

  On the other hand, when the pull-up resistor 35 is connected to the port of the microcomputer 30, the microcomputer 30 is in a state where the LEDs 14a and 14b having the same color temperature are connected to the first step-down chopper circuit 26a and the second step-down chopper circuit 26b (first step). 2 mode). Then, the microcomputer 30 measures the duty ratio of the dimming signal, refers to only the setting table 40a, and sets the target current value corresponding to the duty ratio of the dimming signal to the first step-down voltage via the step-down chopper controller 31. The chopper circuit 26a and the second step-down chopper circuit 26b are set. Thereby, the microcomputer 30 dimmes the LEDs 14a and 14b at the same dimming rate.

  Even if the pull-up resistor 35 is connected to the port of the microcomputer 30, if the duty ratio of the dimming signal is 100%, the microcomputer 30 recognizes the dimming signal as a turn-off signal, and the first step-down chopper circuit. 26a and the second step-down chopper circuit 26b are stopped, and the LEDs 14a and 14b are turned off. When no dimming signal is input, the microcomputer 30 causes the first step-down chopper circuit 26a and the second step-down chopper circuit 26b to output a current of the maximum output current value, and turns on the LEDs 14a and 14b all light.

  FIG. 7C is a diagram illustrating a third example of the configuration of the dimming signal selection unit 33.

  The configuration of the dimming signal selection unit 33 is not limited to that shown in FIGS. 7A and 7B, and one of the two modes (first mode and second mode) is selected for the port of the microcomputer 30. What is necessary is just to be able to input a signal indicating whether or not. For example, as shown in FIG. 7C, the dimming signal selection unit 33 may be configured by a resistance voltage dividing circuit including voltage dividing resistors 36a and 36b. In this case, an A / D converter (analog / digital converter) is provided inside the microcomputer 30. When an analog voltage is input from the dimming signal selection unit 33, the microcomputer 30 determines the voltage level by the A / D converter, and which of the two modes is selected depending on whether the voltage level is equal to or higher than a predetermined threshold value. to decide. Alternatively, for example, the dimming signal selection unit 33 may be a switch that is mounted on a power supply board and can be easily switched from the outside.

  As described above, in the present embodiment, the dimming signal selection unit 33 selectively sets the first mode and the second mode. When the first mode is set by the dimming signal selection unit 33, the control unit 29 outputs a current having a current value corresponding to the duty ratio of the dimming signal measured by the microcomputer 30 from the first step-down chopper circuit 26a. At the same time, a current having a current value corresponding to the period of the dimming signal measured by the microcomputer 30 is output from the second step-down chopper circuit 26b. On the other hand, when the second mode is set by the dimming signal selection unit 33, the control unit 29 has a current value corresponding to one of the duty ratio and the cycle of the dimming signal measured by the microcomputer 30. Current is output from the first step-down chopper circuit 26a and the second step-down chopper circuit 26b.

  As described above, in the present embodiment, by providing the dimming signal selection unit 33, the light source lighting device 20 can be used as a power device with a variable color temperature or as a high output power device to which a large number of LEDs are connected. I can do it. When used as any power supply device, the software and other components built in the microcomputer 30 can be shared, so that the light source lighting device 20 with high efficiency and lower cost can be provided.

  As described above, in this embodiment, the high-power LED lighting device that needs to connect a large number of LEDs 14a and 14b is shared with the color temperature variable LED lighting device that needs to perform current control independently for two outputs. The discrimination method can be realized only by adding the dimming signal selector 33. Therefore, when setting a high-power LED lighting device, it is possible to realize a high-efficiency LED lighting apparatus in which LEDs 14a and 14b are all connected in series, and when setting a color temperature variable light source lighting device, an arbitrary color temperature and light amount can be set. The LED lighting fixture which can be comprised can be comprised easily.

  Further, according to the present embodiment, by incorporating the light source lighting device 20 as described above into the lighting fixture 10, a highly efficient, small, and low-cost color temperature variable LED lighting fixture or a high-power LED lighting fixture is configured. be able to.

  As mentioned above, although embodiment of this invention was described, you may implement combining 2 or more embodiment among these. Alternatively, one of these embodiments may be partially implemented. Or you may implement combining two or more embodiment among these partially.

  DESCRIPTION OF SYMBOLS 10 Lighting fixture, 11 Appliance main body, 12 Power supply line, 13 Connector, 14a, 14b LED, 15 Board | substrate, 16 Wiring, 20 Light source lighting device, 21 Commercial alternating current power supply, 22 Rectifier circuit, 23 Power factor improvement circuit, 24 Switching element 25 control IC, 26a first step-down chopper circuit, 26b second step-down chopper circuit, 27a, 27b switching element, 28a, 28b LED current detection resistor, 29 control unit, 30 microcomputer, 31 step-down chopper control unit, 32 dimming controller, 32a, 32b Slide type volume, 33 Dimming signal selector, 34 Pull down resistor, 35 Pull up resistor, 36a, 36b Voltage dividing resistor, 40a, 40b Setting table.

Claims (11)

A first constant current power supply unit that outputs a current to the first light source and lights the first light source with a light output corresponding to a current value of the current;
A second constant current power supply unit for outputting a current to the second light source and lighting the second light source with a light output corresponding to a current value of the current;
A dimming signal measuring unit that inputs the dimming signal from the dimming signal output device that outputs the dimming signal and measures the duty ratio and cycle of the input dimming signal;
The first constant current power supply unit is controlled to output a current having a current value corresponding to the duty ratio of the dimming signal measured by the dimming signal measurement unit from the first constant current power supply unit, and the second A control unit that controls the constant current power supply unit to output a current having a current value corresponding to a cycle of the dimming signal measured by the dimming signal measurement unit from the second constant current power supply unit. A light source lighting device.   The control unit is configured so that the current value of the current output from the first constant current power supply unit has a substantially linear function relationship with the duty ratio of the dimming signal measured by the dimming signal measurement unit. The light source lighting device according to claim 1, wherein the first constant current power supply unit is controlled.   The control unit is configured so that a current value of a current output from the second constant current power source unit has a substantially linear function relationship with a cycle of the dimming signal measured by the dimming signal measurement unit. The light source lighting device according to claim 1, wherein the second constant current power supply unit is controlled.   The control unit controls the first constant current power source unit so that the light output of the first light source has a substantially linear function relationship with the duty ratio of the dimming signal measured by the dimming signal measurement unit. The light source lighting device according to claim 1, wherein the light source lighting device is controlled.   The control unit controls the second constant current power supply unit so that the light output of the second light source has a substantially linear relationship with the period of the dimming signal measured by the dimming signal measurement unit. The light source lighting device according to claim 1 or 4, characterized in that:   When the duty ratio of the dimming signal measured by the dimming signal measurement unit is a predetermined duty ratio, or when the cycle of the dimming signal measured by the dimming signal measurement unit is predetermined, 6. The light source lighting device according to claim 1, wherein when the period is a period, the first light source and the second light source are turned off.   The control unit causes the first constant current power supply unit and the second constant current power supply unit to output a current having a maximum current value when the dimming signal is not output from the dimming signal output device. The light source lighting device according to claim 1, wherein the light source lighting device is a light source lighting device. The light source lighting device further includes a selection unit that selectively sets the first mode and the second mode,
When the first mode is set by the selection unit, the control unit supplies a current having a current value corresponding to a duty ratio of the dimming signal measured by the dimming signal measuring unit to the first constant current power source. And outputting the current of the current value corresponding to the cycle of the dimming signal measured by the dimming signal measuring unit from the second constant current power source unit, and setting the second mode by the selecting unit In the case where the current is adjusted, a current having a current value corresponding to one of the duty ratio and the cycle of the dimming signal measured by the dimming signal measuring unit is used as the first constant current power source and the second constant current power source. The light source lighting device according to any one of claims 1 to 7, wherein the light source lighting device outputs the light from a light source. A light source lighting device according to any one of claims 1 to 8,
The first light source;
A lighting apparatus comprising: the second light source that is turned on at a color temperature different from that of the first light source.   10. The lighting apparatus according to claim 9, wherein the first light source and the second light source are any one of an LED (Light Emitting Diode) and an EL (Electro Luminescence). A light source lighting device according to any one of claims 1 to 8,
A dimming system comprising the dimming signal output device configured by a microcomputer.

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