JP2013051137A - Led lighting control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED lighting control system which can control the lighting control of an LED lighting device by using a simple structure while suppressing radiation noise from the LED lighting device.SOLUTION: An LED lighting control system includes an LED lighting device comprising at least one LED and a light control unit for performing the light control of the LED lighting device. In this system, the light control unit comprises: light control signal generation means for generating a light control signal responsive to operation of a user; and signal superposition means for superimposing the generated light control signal and a synchronization clock synchronized to the light control signal on an AC power line to transmit them to the LED lighting device, and the LED lighting device comprises: demodulation means for demodulating the light control signal from the AC power line, on the basis of the synchronization clock superimposed on the AC power line, which has been transmitted from the light control unit; and light control means for performing the lighting control of the LED on the basis of the demodulated light control signal.

Description

  The present invention relates to an LED illumination control system that performs dimming of an LED (Light Emitting Diode) illumination device by remote control or the like.

  With the advent of pseudo-white LEDs and the improvement in luminous efficiency accompanying technological advances, various attempts have been made to commercialize lighting devices using LEDs as light sources. By using an LED as a light source, it is possible to achieve higher energy efficiency than incandescent bulbs that have been frequently used as a conventional light source, and further, it is possible to reduce the size, weight, and life of the device.

  A specific configuration of this type of LED lighting device is described in Patent Document 1, for example. Patent Document 1 describes that the dimming of the LED lighting device is remotely controlled by transmitting a dimming control signal from a dimmer such as an external wall switch or a control device to the LED lighting device.

JP 2005-142137 A

  By the way, in Patent Document 1, in order to transmit the dimming control signal to the LED lighting device, it is necessary to wire a signal line different from the power supply line. In order to avoid the addition of this type of signal line, it is conceivable to use power line carrier communication technology such as PLC (Power Line Communication) and PLT (Power Line Telecommunication). When the LED illumination control system is constructed by applying such a technique, the dimming control signal is superimposed on the power supply line and transmitted to the LED lighting device, so that the signal line for the dimming control signal is not necessary.

  However, when the LED lighting control system is constructed by applying the power line carrier communication technology, the clock generator in the LED lighting device for demodulating the dimming control signal becomes a noise generation source, and other devices such as radio and television It is pointed out that this affects Here, a method often performed as a countermeasure against radiation noise is a method in which a noise source is shielded with a metal net and grounded. However, it is difficult for an LED lighting device to take this kind of noise countermeasure due to its structure. It is a measure that cannot be easily adopted.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide LED lighting that can control light control of the LED lighting device with a simple configuration while suppressing radiation noise from the LED lighting device. To provide a control system.

  An LED illumination control system according to an embodiment of the present invention that solves the above problem is a system that includes an LED illumination device including at least one LED and a dimming control unit that performs dimming control of the LED illumination device. The dimming control unit includes a dimming control signal generating unit that generates a dimming control signal according to a user operation, a generated dimming control signal, and a synchronization clock synchronized with the dimming control signal to an AC power line. Signal superimposing means for superimposing and transmitting to the LED lighting device. On the other hand, the LED lighting device is based on the demodulating means for demodulating the dimming control signal from the AC power line based on the synchronous clock superimposed on the AC power line transmitted from the dimming control unit, and on the basis of the demodulated dimming control signal. Dimming control means for dimming the LED.

  According to the present invention, even when a dimming control signal is transmitted using a power line, the brightness and color tone of the LED are simply configured without installing a clock generator on the receiving side (LED lighting device side). Can be controlled. Since the clock generator serving as a radiation noise generation source is not installed in the LED illumination device, it is possible to effectively avoid noise mixing into other devices such as radio and television.

  The signal superimposing means may be configured to superimpose the dimming control signal and the synchronous clock for each half wave of the AC power line. In this case, the demodulation means demodulates the dimming control signal based on the synchronous clock for each half wave of the AC power line, and the dimming control means converts the demodulated dimming control signal to each half wave of the AC power line. Based on dimming LED.

  The dimming control unit may include a pulsating flow generation unit that rectifies some of the AC power lines to generate a pulsating flow. In this case, the signal superimposing means detects each generated pulsating flow, and superimposes the dimming control signal and the synchronization clock in each half wave of the AC power line based on the detection timing of each pulsating flow.

  In the present invention, a plurality of synchronous clocks may be assigned to each bit constituting the dimming control signal. In this case, the demodulating means reads a value synchronized with the N (N ≧ 1) -th synchronization clock assigned to each bit, and obtains the value of each read bit as a demodulation result.

  Further, the dimming control unit may be configured to include a blocking unit that blocks the dimming control signal from the input end of the AC power line to the outside of the dimming control unit and the transmission to the synchronous clock.

  Such blocking means may be configured to cut noise included in the AC power line supplied to the dimming control unit.

  ADVANTAGE OF THE INVENTION According to this invention, the LED illumination control system which can control the light control of an LED illumination apparatus with a simple structure, suppressing the radiation noise from an LED illumination apparatus is provided.

It is a block diagram which shows the structure of the LED illumination control system which concerns on embodiment of this invention. It is a figure which shows the various waveforms for demonstrating operation | movement of the LED illumination control system which concerns on embodiment of this invention. It is a figure which shows the synchronous clock and light control signal of FIG. 2 in detail.

  Hereinafter, an LED illumination control system according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of an LED illumination control system 1 according to an embodiment of the present invention. As shown in FIG. 1, the LED illumination control system 1 includes a dimming control unit 10 and an LED illumination device 20.

  The dimming control unit 10 includes a noise cut filter 11. The noise cut filter 11 cuts external noise included in the AC input while flowing the AC input to the superimposing circuit 12 and the full wave rectifier circuit 13 in the next stage, and outputs the output from the circuit in the LED illumination control system 1 to the outside. Cut off. The AC input from which external noise is blocked is mainly input to the superposition circuit 12 and a part thereof is input to the full-wave rectification circuit 13.

  In addition, the LED illumination control system 1 includes an operation panel 14. The operation panel 14 is an equipped panel embedded in, for example, a wall. In addition to the power switch, the operation panel 14 is provided with a light control volume switch for adjusting brightness, color tone, and the like. From the operation panel 14, an operation signal corresponding to a user's adjustment operation such as luminance and color tone is output and input to the signal processing circuit 16 at the next stage. The operation panel 14 is not limited to the provided panel, and may be a remote controller.

  The AC input to the full-wave rectifier circuit 13 is full-wave rectified, then stabilized by the stabilization circuit 15 at the next stage, and input to the signal processing circuit 16. FIG. 2A shows an output waveform of the stabilization circuit 15. The signal processing circuit 16 detects the operation start voltage of each pulsating flow of the full-wave rectified signal from the stabilization circuit 15. Here, the operation start voltage is a voltage level necessary for the LED to light stably, and indicates a voltage when the threshold value ts is reached in FIG.

  The signal processing circuit 16 generates a dimming control signal of, for example, several tens of bits based on the operation signal from the operation panel 14. The dimming control signal is generated by, for example, an RZ (Return to Zero) method. When the RZ method is adopted, the voltage returns to zero voltage between bits, and there is an advantage that it is easy to take timing. The signal processing circuit 16 detects the operation start voltage for each pulsating flow of the full-wave rectified signal, and during the period in which the level of the full-wave rectified signal is equal to or higher than the threshold value ts (“operation period” shown in FIG. 2B), A synchronous clock (see FIG. 2C) generated by a predetermined oscillation circuit and a dimming control signal (see FIG. 2D) are output separately and simultaneously to the superposition circuit 12.

  3A and 3B are examples of a synchronous clock and a dimming control signal, respectively. A plurality (three in this embodiment) of synchronous clocks are assigned to each bit of the dimming control signal. In the present embodiment, a value synchronized with the second of the three synchronization clocks constitutes the dimming control signal. In the example of FIGS. 3A and 3B, the dimming control signal is “1, 1,...”. The reason that the value synchronized with the first synchronization clock is not applied (in other words, the value synchronized with the second and subsequent synchronization clocks is applied) is to avoid a demodulation error due to synchronization deviation. However, in another embodiment, a value synchronized with the first synchronous clock may be applied.

  The superimposing circuit 12 is a synchronous clock output from the signal processing circuit 16 during a period corresponding to the operation period (see FIG. 2B) of each half wave of the AC voltage supplied via the noise cut filter 11. 2 (c)) and dimming control signal (see FIG. 2 (d)) are superimposed on the AC voltage. For superimposing the synchronous clock and the dimming control signal, different carrier waves having a higher frequency than the AC voltage are used. The AC voltage after signal superimposition is transmitted to the LED lighting device 20 installed at a position (for example, above the ceiling) away from the operation panel 14 via a single AC power line.

  The LED lighting device 20 includes a separation filter 21. An AC voltage transmitted from the dimming control unit 10 (superimposition circuit 12) is input to the separation filter 21. The separation filter 21 outputs an alternating voltage to the power supply circuit 22, separates a synchronous clock and a dimming control signal in the alternating voltage carried by carrier waves having different frequencies, and outputs the separated signals to the LED drive circuit 23. .

  The power supply circuit 22 is, for example, a simple full-wave rectification circuit that full-wave rectifies an AC voltage transmitted from the dimming control unit 10 (superimposition circuit 12) via the separation filter 21, and an output stage includes an LED. A drive circuit 23 is connected.

  At the output stage of the LED drive circuit 23, a plurality of LEDs 24 installed in an array are connected to the entire light emitting region of the LED lighting device 20. The LED drive circuit 23 supplies a drive current to each LED 24 by supplying power from the power supply circuit 22 (the power waveform is shown with reference to FIG. 2A), and causes each LED 24 to emit light. More specifically, the LED drive circuit 23 controls the light emission of each LED 24 according to the synchronous clock and the dimming control signal separated by the separation filter 21. The LED drive circuit 23 reads a value synchronized with the second synchronization clock (see FIG. 3A) of the third assigned to each bit (see FIG. 3B) of the dimming control signal. The luminance and color tone of each LED 24 is controlled to emit light according to the read value.

  Each LED 24 emits light during a period in which a voltage equal to or higher than the threshold ts of each pulsating current is applied (during a period corresponding to the operation period (see FIG. 2B)), and is extinguished during other periods. That is, each LED 24 blinks at a frequency twice that of the AC voltage. However, since the human eye cannot follow such blinking speed, each LED 24 appears to be continuously lit on the human eye. Each LED 24 is a pseudo-white LED that combines, for example, a phosphor with high visibility and yellow fluorescence and a blue LED (or ultraviolet light-emitting LED). In another embodiment, it may be replaced with a white LED of the RGB three-color system.

  Incidentally, the power supply to the LED drive circuit 23 is interrupted for each pulsating flow as shown in FIG. For this reason, the luminance and color tone information demodulated by the LED drive circuit 23 is reset for each pulsating flow. However, since the dimming control signal (see FIG. 2D) is transmitted superimposed on each pulsating flow, the LED driving circuit 23 does not reset the next pulsating flow even if the information on luminance and color tone is reset once. By reading the value of the dimming control signal, it is possible to control the light emission of each LED 24 with an appropriate luminance and color tone according to the operation of the operation panel 14.

  As described above, in the present embodiment, even when the dimming control signal is transmitted using the power line, the brightness and color tone of the LED 24 are not installed on the receiving side (the LED lighting device 20 side). Can be controlled with a simple configuration. Since the clock generator serving as a radiation noise generation source is not installed in the LED illumination device 20, it is possible to effectively avoid noise mixing in other devices such as a radio and a television.

  Further, as described above, a simple circuit configuration is sufficient for the power supply circuit 22 in the LED lighting device 20. The power supply circuit 22 does not need even a smoothing circuit made of an electrolytic capacitor. Since it is not necessary to mount an electrolytic capacitor having a relatively short life in the power supply circuit, it is advantageous for extending the life of the LED lighting device 20. Further, since the power supply circuit 22 is not a switching power supply, the radiation noise is small. As a price for adopting a simple configuration, information on luminance and color tone is reset for each pulsating flow and cannot be retained. However, in this embodiment, this reset is effectively used. Specifically, in the LED drive circuit 23, even when a demodulation error occurs in one pulsating flow and a luminance change or the like that does not conform to the operation of the operation panel 14 occurs, the LED driving circuit 23 is reset at the end of the pulsating flow. Therefore, if the demodulation is normal at the next pulsating flow, an appropriate luminance change or the like is performed. That is, the trouble due to the demodulation error can be solved immediately without being perceived by human eyes.

  The above is the description of the embodiment of the present invention. The present invention is not limited to the above-described configuration, and various modifications can be made within the scope of the technical idea of the present invention. For example, in this embodiment, three synchronization clocks are assigned to each bit of the dimming control signal, but in another embodiment, only one synchronization clock may be assigned.

DESCRIPTION OF SYMBOLS 1 LED illumination control system 10 Dimming control unit 11 Noise cut filter 12 Superimposition circuit 13 Full wave rectification circuit 14 Operation panel 15 Stabilization circuit 16 Signal processing circuit 20 LED illumination device 21 Separation filter 22 Power supply circuit 23 LED drive circuit 24 LED

Claims (6)

An LED illumination control system comprising: an LED illumination device including at least one LED; and a dimming control unit that performs dimming control of the LED illumination device,
The dimming control unit includes:
A dimming control signal generating means for generating a dimming control signal according to a user operation;
A signal superimposing means for superimposing the generated dimming control signal and a synchronous clock synchronized with the dimming control signal on an AC power line and transmitting it to the LED lighting device;
Have
The LED lighting device
Demodulating means for demodulating the dimming control signal from the AC power line based on a synchronous clock superimposed on the transmitted AC power line;
Dimming control means for dimming the LED based on the demodulated dimming control signal;
An LED lighting control system comprising: The signal superimposing means superimposes the dimming control signal and the synchronous clock for each half wave of the AC power line,
The demodulation means performs demodulation of the dimming control signal based on the synchronous clock for each half wave of the AC power line,
2. The LED lighting control system according to claim 1, wherein the dimming control unit performs dimming of the LED based on the demodulated dimming control signal for each half wave of the AC power line. The dimming control unit includes:
Pulsating flow generating means for rectifying some of the AC power lines to generate a pulsating flow;
The signal superimposing means detects each generated pulsating flow, and superimposes the dimming control signal and the synchronous clock in each half wave of the AC power line based on the detection timing of each pulsating flow. The LED lighting control system according to claim 2, characterized in that A plurality of the synchronous clocks are assigned to each bit constituting the dimming control signal;
The demodulating means reads a value synchronized with an Nth (N ≧ 1) -th synchronization clock assigned to each bit, and obtains a value of each read bit as a demodulation result. The LED illumination control system according to any one of claims 1 to 3. The dimming control unit includes:
5. The device according to claim 1, further comprising: a blocking unit that blocks transmission of the dimming control signal and the synchronization clock from the input end of the AC power line to the outside of the dimming control unit. The LED illumination control system according to claim 1.   The LED lighting control system according to claim 5, wherein the blocking unit cuts noise included in the AC power line supplied to the dimming control unit.

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