KR20140130333A - Led light device for broadcast - Google Patents

Abstract

The present invention relates to an LED lighting device for use in broadcasting. The LED lighting device comprises: a light source including first and second light sources which include a plurality of LEDs and generate light having different color temperatures; a power supply which converts an AC voltage provided from a dimmer into a DC voltage; a square wave generator which detects a phase angle of the AC voltage supplied from the dimmer and outputs a dimming signal according to the detected phase angle by using a photo coupler; and a controller which independently controls a dimming rate of the first and second light sources according to the dimming signal and an external color temperature variable signal.

Description

{LED LIGHT DEVICE FOR BROADCAST}

The present invention relates to a broadcasting LED lighting apparatus.

2. Description of the Related Art In recent years, LEDs have emerged as light sources in lighting devices used for broadcasting. LEDs have a longer lifetime, lower power consumption, and easier maintenance and management than halogen lamps and fluorescent lamps.

Meanwhile, in the broadcasting lighting apparatus, dimming driving for adjusting the luminance of the light source is indispensably required. In the conventional broadcasting LED lighting apparatus, a dimmer and a separate communication line or an analog control line . This has the problems of installation burden due to facility change and cost increase.

In addition, a TRIAC dimmer, which is widely used as a dimmer in an LED lighting device, is provided with a bleed circuit to prevent flicker. However, in a large system such as a broadcasting LED lighting device, power loss due to a bleed circuit Is too large to apply.

In addition, since the LED lighting apparatus for broadcasting is required to vary the color temperature in a range of about 3000K to 6000K depending on the application, the conventional LED lighting apparatus for broadcasting is a system in which the luminance is controlled by changing only the phase angle of the input AC power. Was practically impossible.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a digital dimming device capable of dimming driving by connecting to a conventional dimmer device without a separate communication line or analog control line, An object of the present invention is to provide an LED lighting device.

According to an aspect of the present invention, there is provided an LED lighting apparatus for broadcasting comprising: a light source device including a plurality of LEDs and including a first light source and a second light source for generating light having different color temperatures; A power supply unit for converting the AC power supplied from the dimmer into a DC voltage; A square wave generator for detecting a phase angle of the AC power supplied from the dimmer and outputting a dimming signal according to the detected phase angle using an optocoupler; And a controller for independently controlling a dimming rate of the first and second light sources according to the dimming signal and an externally provided color temperature variable signal.

The square wave generator includes a primary circuit connected to an output terminal of the dimmer; And a secondary side circuit which is insulated from the primary side circuit and outputs the dimming signal in accordance with light provided from the primary side circuit.

Wherein the primary circuit includes: a field effect transistor for generating a current according to a phase angle of an AC power supplied from the dimmer; And a photodiode for generating light in accordance with a current provided from the field effect transistor.

The primary side circuit comprising: first and second resistors connected in series between an output terminal and a ground terminal of the dimmer; A third resistor coupled between the source of the field effect transistor and the ground; A fourth resistor coupled between the cathode of the photodiode and the ground; Further comprising a zener diode having a cathode connected to the gate of the field effect transistor and an anode connected to the ground terminal; And a gate of the field effect transistor is connected to a voltage dividing node between the first and second resistors.

The third resistor has a range of 100? To 1000?, And the fourth resistor has a range of 1000? To 10000?.

And the field effect transistor is of an N type.

A phototransistor connected between the power supply voltage supply terminal and the ground terminal, the photocoupler including the photodiode; And a first inverter and a second inverter connected in series between the drain of the phototransistor and the output terminal of the square wave generator.

The secondary circuit includes a fifth resistor connected between the power supply voltage supply terminal and the phototransistor; And a sixth resistor connected between the phototransistor and the ground terminal.

The control device comprising: a microprocessor for outputting first and second pulse width modulation signals according to the dimming signal and the color temperature variable signal; A first LED driver for driving the first light source in response to the first pulse width modulation signal; And a second LED driver for driving the second light source in response to the second pulse width modulation signal.

Wherein the first light source comprises a plurality of LEDs for generating light having a color temperature in the range of about 3000K to 3500K and the second light source comprises a plurality of LEDs for generating light having a color temperature in the range of about 5000K to 6000K .

The present invention uses a photocoupler to generate a rectangular wave synchronized with the phase angle of the AC power inputted from the dimmer 12 by the square wave generating device 6 so that the primary side and the secondary side circuit of the apparatus constituting the system are isolated Stable driving is possible, and it is strong against noise because it uses light. The present invention also relates to a light emitting device comprising a first light source 18a composed of a plurality of LEDs for generating light having a color temperature in the range of about 3000K to 3500K and a plurality of LEDs for generating light having a color temperature in the range of about 5000K to 6000K And the first and second LED drivers 16a and 16b individually drive the first and second LED light sources 18b and 18b to display color temperatures ranging from about 3000K to 6000K while implementing dimming.

1 is a configuration diagram of a broadcasting LED lighting apparatus according to an embodiment of the present invention.
FIG. 2 is an example of an AC power source that is phase-cut and output in the dimmer 12 shown in FIG.
3 is an illustration of a dimming signal dim output from the square wave generator 16 shown in Fig.
Fig. 4 is a configuration diagram of the square wave generator 6 shown in Fig.
5 is a diagram showing output waveforms of the respective nodes shown in FIG.
Fig. 6 is a configuration diagram of the control device 10 and the light source device 10 shown in Fig.
7 is a configuration diagram of the microprocessor 14 shown in Fig.

Hereinafter, a broadcasting LED lighting apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram of a broadcasting LED lighting apparatus according to an embodiment of the present invention. FIG. 2 is an example of an alternating-current power source that is phase-cut and output in the dimmer 12 shown in FIG. 3 is an illustration of a dimming signal dim output from the square wave generator 16 shown in Fig.

1, a broadcasting LED lighting apparatus 2 according to an embodiment of the present invention includes a power source device 4, a square wave generator device 6, a control device 8, and a light source device 10 do.

The LED lighting apparatus 2 for broadcasting according to the present invention is connected to a dimmer 12 and drives the LED light source according to the phase angle of the AC power supplied from the dimmer 12. The dimmer 12 is an AC controller Are conventionally known. For example, the dimmer 10 can output AC power as shown in FIG. 2 by phase-cutting a commercial power source which is a sinusoidal wave of 100 V to 220 V and 60 Hz.

The power supply unit 4 is composed of a Switching Modulation Power Supply (SMPS). The power supply device 4 converts the AC power supplied from the dimmer 12 to a DC voltage and supplies the converted DC voltage to the LED driver 16 of the control device 8 as the LED driving voltage VDD. The LED driving voltage VDD output from the power supply unit 4 is a DC voltage corresponding to an effective value (r.m.s) of about 10% of the output of the dimmer 12 and can be set in a range of about 20V to 24V. Although not shown, the power supply device 4 may further include a power factor correcting device for improving the power factor by controlling phases of voltage and current.

The square wave generator 6 detects the phase angle of the AC power supplied from the dimmer 12 and generates the dimming signal dim according to the detected phase angle to supply the dimming signal dim to the microprocessor 14 of the control device 8 . The dimming signal dim is a square wave signal having a predetermined pulse width and the microprocessor 14 controls the LED driver 16 according to the pulse width of the dimming signal dim to control the dimming of the light source device 10. [ .

3, the pulse width of the dimming signal dim output from the square wave generator 6 is in the range of 0% to 100% depending on the phase angle of the AC power input from the dimmer 12 . 3 (a) shows a dimming signal dim having a pulse width of about 75%, and FIG. 3 (b) shows a dimming signal dim having a pulse width of about 43% And FIG. 3 (c) shows a dimming signal dim having a pulse width of about 15%.

The control device 10 generates a pulse width modulation (PWM) signal PWM in accordance with the dimming signal dim provided from the square wave generator 6 and the externally provided color temperature variable signal CT And supplies the driving current to the LED of the light source device 10 using the LED driving voltage VDD provided from the power source device 4 and outputs the PWM signal PWM And an LED driver 16 for controlling the dimming rate of the LED of the light source device 10 in response to the control signal.

The light source device 10 has a plurality of LED arrays. Specifically, the plurality of LED arrays provided in the light source device 10 include a first light source 18a composed of a plurality of LEDs for generating light having a color temperature in the range of about 3000K to 3500K, And a second light source 18b composed of a plurality of LEDs for generating light having a temperature. The first and second light sources 18a and 18b are driven independently of each other and generate light having a color temperature in the range of about 3000K to 6000K under the control of the LED driver 16. [

Particularly, the present invention uses a photocoupler to generate a rectangular wave synchronized with the phase angle of the AC power inputted from the dimmer 12, It can be stably driven and is resistant to noise because it uses light. The present invention also relates to a light emitting device comprising a first light source 18a composed of a plurality of LEDs for generating light having a color temperature in the range of about 3000K to 3500K and a plurality of LEDs for generating light having a color temperature in the range of about 5000K to 6000K And the first and second LED drivers 16a and 16b individually drive the first and second LED light sources 18b and 18b to display color temperatures ranging from about 3000K to 6000K while implementing dimming. The present invention will be described in more detail as follows.

Fig. 4 is a configuration diagram of the square wave generator 6 shown in Fig. 5 is a diagram showing output waveforms of the respective nodes shown in FIG.

The rectangular wave generating device 6 shown in Fig. 4 includes a primary side circuit 6a and a secondary side circuit 6b which are insulated from each other.

The primary side circuit 6a includes a field effect transistor (hereinafter referred to as FET) T1, first to fourth resistors R1 to R4, a photodiode PD, and a zener diode ZD do.

The first and second resistors R1 and R2 are connected in series between the output terminal of the dimmer 12 and the ground GND. Hereinafter, a node between the first and second resistors R1 and R2 will be defined as a voltage dividing node n1.

The FET T1 is turned on or off according to the voltage state of the voltage divider node n1 defined between the first and second resistors R1 and R2 and a predetermined current flows between the drain and the source at the turn- do. This FET T1 is of an N type and is turned on according to the voltage level of the voltage divider node n1. To this end, the FET T1 has a gate connected to the voltage dividing node n1, a drain connected to the output terminal of the dimmer 12, and a source connected to the ground terminal GND. The FET T1 is turned off during the phase cut period (period A in FIG. 5) and is turned on during the remaining period (period B in FIG. 5).

The photodiode PD constitutes a photo coupler together with the phototransistor T2 of the secondary circuit 6b. In the photodiode PD, the anode is connected to the drain of the FET T1 and the cathode is connected to the ground GND, thereby generating light in accordance with the current flowing through the FET T1. The FET T1 supplies a current in a period during which the AC power input from the dimmer 12 is not phase-cut (period B in Fig. 5), and the photodiode PD generates light in the corresponding period.

The third resistor R3 is connected between the source of the FET T1 and the ground GND. This third resistor R3 serves as a load having a range of 100? To 1000 ?.

The fourth resistor R4 is connected between the cathode of the photodiode PD and the ground GND. The fourth resistor R4 serves as a load having a range of 1000 OMEGA to 10000 OMEGA.

The Zener diode ZD is connected to the gate of the FET T1 to prevent an overcurrent from flowing from the output terminal of the dimmer 12 to the gate of the FET T1. To this end, the zener diode ZD has a cathode connected to the gate of the FET T1 and an anode connected to the ground GND. Accordingly, the Zener diode ZD prevents the overvoltage exceeding the Zener voltage from flowing into the gate of the FET T1, thereby preventing damage to the FET T1.

The present invention prevents unwanted overcurrents in detecting the phase angle of the AC power input from the dimmer 12 by allowing the third and fourth resistors R3 and R4 to have a relatively large resistance value as described above.

On the other hand, the secondary side circuit 6b includes the phototransistor T1, the fifth and sixth resistors R5 and R6, and the first and second inverters IV1 and IV2.

The phototransistor T2 together with the photodiode PD of the primary circuit 6a constitutes an optocoupler. The phototransistor T2 is connected between the power supply voltage VCC supply terminal and the ground terminal GND and is connected to the power supply voltage VCC supply terminal and the ground terminal GND according to the light generated in the photodiode PD of the primary side circuit 6a. So that a predetermined current flows between the terminals GND.

The fifth resistor R5 is connected between the supply voltage VCC supply terminal and the source of the phototransistor T2 to serve as a resistor for limiting the current flowing into the phototransistor T2 from the supply voltage VCC supply terminal.

The sixth resistor R6 is a load resistor connected between the drain of the phototransistor T2 and the ground GND.

The first and second inverters IV1 and IV2 are connected in series between the drain of the phototransistor T2 and the output terminal of the square wave generator 6. The first and second inverters IV1 and IV2 remove the noise component of the square wave output through the drain of the phototransistor T2. The square wave output through the first and second inverters IV1 and IV2 is supplied to the microprocessor 14 of the control device 8 as the dimming signal dim.

The operation of the square wave generator 6 will now be described with reference to Figs. 4 and 5. Fig.

The AC power inputted from the dimmer 12 passes through the rectifier and is divided according to the resistance ratio of the first and second resistors R1 and R2. At this time, the voltage of the voltage-dividing node n1 between the first and second resistors R1 and R2 is divided into an A period in which the AC power input from the dimmer 12 is phase-cut and is 0 V, and a B period in which the AC power is not 0.

In the period A, the voltage state of the voltage-dividing node n1 is 0 V, so that the FET T1 is turned off.

On the other hand, in the period B, the voltage state of the voltage-dividing node n1 is larger than 0 V, and the FET T1 is turned on to supply the current to the photodiode PD. Then, the photodiode PD emits light, and a current flows through the phototransistor T2.

The current waveform output through the phototransistor T2 is stabilized via the first and second inverters IV1 and IV2 and then output to the output terminal of the square wave generator 6. [

Thus, the square wave generator 6 outputs the dimming signal dim having pulses synchronized with the period when the AC power inputted from the dimmer 12 is not phase-cut (period B in Fig. 5).

As described above, according to the present invention, by using the photo coupler to generate the square wave synchronized with the phase angle of the AC power inputted from the dimmer 12, the primary side and the secondary side circuit of the apparatus constituting the system can be insulated, It can be driven, and it is strong against noise because it uses light. The third and fourth resistors R3 and R4 connected to the drain of the FET T1 have a relatively high resistance value as a load resistor to detect the phase angle of the AC power input from the dimmer 12 Reduces power consumption by preventing unnecessary overcurrent.

Fig. 6 is a configuration diagram of the control device 10 and the light source device 10 shown in Fig. 7 is a configuration diagram of the microprocessor 14 shown in Fig.

6, the microprocessor 14 generates the first and second PWM signals PWM1 and PWM2 according to the dimming signal dim provided from the square wave generator 6 and the color temperature variable signal CT provided from the outside, . The first PWM signal PWM1 is supplied to the first LED driver 16a that drives the first light source 10a. The second PWM signal PWM2 is supplied to the second LED driver 16b that drives the second light source 10b. The microprocessor 14 controls the dimming and the color temperature of the first and second light sources 10a and 10b according to the dimming signal dim and the color temperature variable signal CT.

7, the microprocessor 14 includes an A / D converter 14a for converting the digital signal into a dimming signal dim and a color temperature variable signal CT which are inputted analogously, The dimming rate of each of the first and second light sources 10a and 10b is calculated according to the dimming information of the dimming signal dim provided from the A / D converter 14a and the color temperature information of the color temperature variable signal CT, The first and second light sources 10a and 10b controlling the dimming rates of the first and second light sources 10a and 10b according to the operation information provided from the operation unit 14b; And a PWM module 14c for outputting the PWM signals PWM1 and PWM2.

On the other hand, the color temperature variable signal CT may be a user's analog input signal or a digital signal input through a DMX communication line or the like.

The first LED driver 16a controls dimming of the first light source 10a of the light source device 10 in response to the first PWM signal PWM1 provided from the microprocessor 14. [

The second LED driver 16b controls dimming of the second light source 10b of the light source device 10 in response to the second PWM signal PWM2 provided from the microprocessor 14. [

As described above, the present invention provides a light emitting device including a first light source 18a composed of a plurality of LEDs for generating light having a color temperature in a range of about 3000K to 3500K, a plurality of LEDs 18b for generating light having a color temperature in the range of about 5000K to 6000K And the first and second LED drivers 16a and 16b drive the LEDs 16a and 16b individually, thereby achieving color temperature in the range of about 3000K to 6000K while implementing dimming.

For example, the first light source 18a may be a light source having a color temperature of 3200K, and the second light source 18b may be a light source having a color temperature of 5600K. In this case, as shown in Table 1, the dimming rate of the first light source 18a is changed from 100% to 0%, and the dimming rate of the second light source 18b is changed from 0% to 100% It is possible to linearly control light having a color temperature in the range of 5600K.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. Will be clear to those who have knowledge of.

4: Power supply unit 6: Square wave generating unit
8: Control device 10: Light source device
CT: variable color temperature signal dim: dimming signal
VDD: LED driving voltage

Claims (10)

A light source device having a plurality of LEDs and configured by a first light source and a second light source for generating light having different color temperatures;
A power supply unit for converting the AC power supplied from the dimmer into a DC voltage;
A square wave generator for detecting a phase angle of the AC power supplied from the dimmer and outputting a dimming signal according to the detected phase angle using an optocoupler;
And a controller for independently controlling a dimming rate of the first and second light sources according to the dimming signal and an externally supplied color temperature variable signal. The method according to claim 1,
The square wave generator
A primary side circuit connected to an output terminal of the dimmer;
And a secondary side circuit which is insulated from the primary side circuit and outputs the dimming signal in accordance with light provided from the primary side circuit. The method of claim 2,
The primary side circuit
A field effect transistor for generating a current according to a phase angle of an AC power source provided from the dimmer;
And a photodiode for generating light according to a current provided from the field effect transistor. The method of claim 3,
The primary side circuit
First and second resistors connected in series between an output terminal and a ground terminal of the dimmer;
A third resistor coupled between the source of the field effect transistor and the ground;
A fourth resistor coupled between the cathode of the photodiode and the ground;
Further comprising a zener diode having a cathode connected to the gate of the field effect transistor and an anode connected to the ground terminal;
And a gate of the field effect transistor is connected to a voltage-dividing node between the first and second resistors. The method of claim 4,
Wherein the third resistor has a range of 100? To 1000?, And the fourth resistor has a range of 1000? To 10000 ?. The method of claim 3,
Wherein the field effect transistor is of N type. The method of claim 3,
The secondary side circuit
A phototransistor configured to form the photocoupler together with the photodiode, the phototransistor being connected between a power supply voltage supply terminal and a ground terminal;
And a first inverter and a second inverter connected in series between a drain of the phototransistor and an output terminal of the square wave generator. The method of claim 7,
The secondary side circuit
A fifth resistor connected between the power supply voltage supply terminal and the phototransistor;
And a sixth resistor connected between the phototransistor and the ground terminal. The method according to claim 1,
The control device
A microprocessor for outputting first and second pulse width modulation signals according to the dimming signal and the color temperature variable signal;
A first LED driver for driving the first light source in response to the first pulse width modulation signal;
And a second LED driver for driving the second light source in response to the second pulse width modulation signal. The method according to claim 1,
Wherein the first light source comprises a plurality of LEDs for generating light having a color temperature in the range of about 3000K to 3500K,
Wherein the second light source comprises a plurality of LEDs for generating light having a color temperature in a range of about 5000K to 6000K.

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