KR102118623B1 - Flicker Prevention LED Lightening Device - Google Patents

Abstract

The present invention relates to an LED lighting device that prevents flickering, and more specifically, AC power is input and driven to prevent flickering of an LED by removing ripple current, preventing flickering when lighting is turned off, or AC power or The present invention relates to an LED lighting device that prevents flickering, which can provide broadcast lighting that can maintain lighting even when an LED is abnormal.

Description

Flicker Prevention LED Lightening Device

The present invention relates to an LED lighting device that prevents flickering, and more specifically, AC power is input and driven to prevent flickering of an LED by removing ripple current, preventing flickering when lighting is turned off, or AC power or The present invention relates to an LED lighting device that prevents flickering, which can provide broadcast lighting that can maintain lighting even when an LED is abnormal.

In general, the LED lighting device is made to be able to adjust the brightness of the LED by changing the current supplied based on a constant voltage to adjust the brightness, or by using a current control method that detects the current and flows a constant current. It is widely used as a device.

The power supply circuit in the LED lighting device is difficult to implement a perfect direct current, and this causes the ripple component (120 ㎐) to operate in a mixed form with direct current.

Normally, even if the ripple component is more than 15% of the total DC level, it does not feel due to the afterimage effect of the human eye, but a sensitive person senses flicker by detecting it, and because the DC level is fluctuating, the digital camera, etc. You can check accurately through. Since flicker is recognized through a digital camera or the like, there is a need to suppress the occurrence of flicker in the case of lighting used for broadcasting.

The object of the present invention is to receive AC power and drive it, remove the ripple current to prevent flicker of the LED, prevent flickering when the lights go out, and broadcast lights that can maintain the lighting even when the AC power or LED is abnormal. It is to provide an LED lighting device that prevents flicker that can be provided.

In order to solve the above problems, the present invention is an LED lighting device that prevents flicker, consisting of one or more LEDs to provide lighting under control; An AC power supply for supplying AC power; A rectifying unit for converting AC power into DC power; A DC/DC converter that controls the driving voltage of the DC power supply; An LED control unit that performs lighting, lighting and illuminance control of the LED unit; A ripple removing unit positioned between the DC/DC converter and the LED unit to remove ripple current of a power source; And a flicker prevention unit that prevents flickering that occurs when the LED lights are turned off. It provides an LED lighting device comprising a.

In the present invention, the ripple elimination unit may include one or more electrolytic capacitor filters that smooth the drive voltage and remove ripple components from current components flowing through the LED unit.

In the present invention, the flicker prevention unit, the first resistor and the second resistor connected to the contact of the ripple removal unit and the LED unit; A first switching element configured between the second resistor and the ground terminal and receiving a control signal by the first resistor to be turned on or off; And a second switching element configured between the first resistor and the ground terminal to receive control signals of the LED control unit and turn them on or off. It may include.

In the present invention, the LED unit is composed of one or a plurality of LEDs, LED modules that emit light by receiving power; A preliminary LED module composed of one or a plurality of LEDs and receiving power and emitting light; And an LED management unit that applies power to the LED module according to the control signal of the LED control unit, determines whether the LED module is operating normally, and applies power to the spare LED module when the LED module does not operate normally. It may include.

In the present invention, the LED management unit, the LED module control unit for applying power to the LED module according to the control signal of the LED control unit; An LED module monitoring unit to determine whether the LED module is operating normally; And a preliminary LED module control unit that applies power to the preliminary LED module when the LED module does not operate normally. It may include.

In the present invention, the LED unit includes two or more LED modules, and the LED management unit may apply power to a spare LED module when any one of the two or more LED modules does not operate normally.

In the present invention, the LED control unit, the first LED control unit for controlling the power supplied to the LED module receives the illumination of the illumination; And a second LED controller controlling the current supplied to the LED module under the control of the first LED controller. Including, the first LED control unit, an illuminance input unit for receiving the illuminance of the LED light; And a control panel unit for determining whether the received illuminance is equal to or greater than a predetermined threshold illuminance. Including, the second LED control unit, PWM control unit for controlling the illuminance of the LED unit in the PWM method when the received illuminance is less than a predetermined threshold illuminance; And a DC control unit that controls the illuminance of the LED unit using a DC control method when the received illuminance is equal to or greater than a predetermined threshold illuminance. It may include.

In the present invention, the PWM control unit may control the illuminance of the LED unit by adjusting the duty ratio based on the received illuminance while keeping the voltage supplied to the LED unit constant.

In the present invention, the DC control unit may control the illuminance of the LED unit by adjusting the voltage supplied to the LED unit based on the received illuminance.

In the present invention, the LED lighting device comprises: an auxiliary power supply unit capable of supplying power to the LED lighting device; Further comprising, when the LED control unit is not supplied with power from the AC power supply unit, it may receive power from the auxiliary power supply unit to control the LED lighting.

According to an embodiment of the present invention, in an LED lighting driven by receiving an AC voltage, an effect capable of suppressing the occurrence of flicker can be exhibited.

According to an embodiment of the present invention, it is possible to exert an effect of preventing flicker that may occur when the LED light is turned off.

According to an embodiment of the present invention, when controlling the illuminance of the LED light, the PWM method is used when the light is less than the critical illuminance, and the DC control method is used to control the illuminance while suppressing flicker or flicker. .

According to an embodiment of the present invention, even if an abnormality occurs in the LED module, it is possible to exert the effect of providing continuous lighting by driving the preliminary LED module.

According to an embodiment of the present invention, even if an abnormality occurs in the AC power supply, the power can be supplied by the auxiliary power supply to exert the effect of providing continuous lighting.

1 is a circuit diagram schematically showing a circuit of a direct-link type LED lighting that receives AC power and drives it.
2 is a graph schematically showing the VI characteristics and dynamic resistance of the LED.
3 is a graph schematically showing a relationship between voltage and current in an LED light driven by receiving AC power.
4 is a graph schematically showing a voltage change when the LED lighting device including a ripple elimination unit using a capacitor is turned off.
5 is a block diagram schematically showing the configuration of an LED lighting device according to an embodiment of the present invention.
6 is a view schematically showing the configuration of an LED lighting device according to an embodiment of the present invention.
7 is a view schematically showing the configuration of an LED unit according to an embodiment of the present invention.
8 is a block diagram schematically showing the internal configuration of the LED management unit according to an embodiment of the present invention.
9 is a block diagram schematically showing the configuration of an LED lighting device according to another embodiment of the present invention.
10 is a block diagram schematically showing the internal configuration of the LED control unit according to an embodiment of the present invention.
11 is a graph schematically showing a control value according to the illumination control of the LED lighting according to an embodiment of the present invention.
12 is a block diagram schematically showing the configuration of an LED lighting device according to another embodiment of the present invention.

In the following, various embodiments and/or aspects are now disclosed with reference to the drawings. In the following description, for purposes of explanation, a number of specific details are disclosed to assist in the overall understanding of one or more aspects. However, it will also be appreciated by those skilled in the art that this aspect(s) can be practiced without these specific details. The following description and the annexed drawings set forth in detail certain illustrative aspects of the one or more aspects. However, these aspects are exemplary and some of the various methods in the principles of the various aspects may be used, and the descriptions described are intended to include all such aspects and their equivalents.

In addition, various aspects and features will be presented by a system that may include multiple devices, components and/or modules, and the like. The various systems may also include additional devices, components and/or modules, and/or may not include all of the devices, components, modules, etc. discussed in connection with the drawings. It must be understood and recognized.

As used herein, "an embodiment", "yes", "a good", "an example", etc. may not be construed as any aspect or design described being better or more advantageous than the other aspect or designs. . The terms'~unit','component','module','system', and'interface' used in the following generally mean a computer-related entity, for example, hardware, hardware And software, can mean software.

Also, the terms “comprises” and/or “comprising” mean that the feature and/or component is present, but excludes the presence or addition of one or more other features, elements, and/or groups thereof. It should be understood as not.

Further, terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from other components. For example, the first component may be referred to as a second component without departing from the scope of the present invention, and similarly, the second component may be referred to as a first component. The term and/or includes a combination of a plurality of related described items or any one of a plurality of related described items.

In addition, in the embodiments of the present invention, unless defined otherwise, all terms used herein, including technical or scientific terms, are generally understood by those skilled in the art to which the present invention pertains. It has the same meaning as that. Terms, such as those defined in a commonly used dictionary, should be interpreted as having meanings consistent with meanings in the context of related technologies, and are ideal or excessively formal meanings unless explicitly defined in the embodiments of the present invention. Is not interpreted as

1 is a circuit diagram schematically showing a circuit of a direct-link type LED lighting that receives AC power and drives it.

Referring to (A) of FIG. 1, the direct-connected LED lighting device that receives AC power and drives the AC power supply unit 10 for supplying AC power, a rectifying unit 20 for converting AC power to DC, and LED 30 Consists of.

As shown in (A) of FIG. 1, the rectifying unit 20 composed of the bridge diode BD receives AC power from the AC power supply 10 and converts it to DC. In this case, the LED 30 generates flicker corresponding to twice the commercial voltage frequency according to the fluctuation of the full-wave rectified voltage provided from the bridge diode BD, and also the dynamic resistance of the LED 30. As a result, a period in which the LED 30 does not light is generated, and thus, fluctuations in overall brightness appear periodically. This flicker is not distinguished with the naked eye, but when used as lighting for industrial lighting or image processing systems, the image quality of the image is affected and the luminous efficiency of the LED 30 is reduced.

As a countermeasure to this, the flicker phenomenon can be improved by connecting and using the capacitor 40 in parallel with the LED 30 as shown in FIG. 1B.

2 is a graph schematically showing V-I characteristics and dynamic resistance of an LED.

The LED converts the current according to the voltage applied in the forward direction based on a single PN junction into light. The LED is a voltage that allows holes and free electrons to pass through the depletion layer of the PN junction, and a voltage greater than or equal to Vf1 of 0.6 to 0.7 V starts to flow, and the amount of current depends on the voltage applied to the PN junction. This increases. Therefore, referring to the dotted line graph on the left side of FIG. 2, the dynamic resistance of the diode has a very large resistance value because the slope of the tangent line to the VI characteristic curve is close to horizontal in the vicinity of Vf1, and the applied voltage increases. Since it is close to the vertical direction, it has the characteristic of reducing the dynamic resistance. The solid line graph on the right side of FIG. 2 is an example of the V-I characteristic of a conventional lighting LED, and the lighting LED has a relatively large forward voltage Vfn compared to a single junction LED because it is implemented by connecting a plurality of LEDs in series. For example, in the case of AC 220 V 50 Watt lighting LED, since 84 LEDs are connected in series, the forward voltage Vfn is 0.6 V X 84 ≒ 50 V. Therefore, when the voltage applied to the AC 220 V 50 Watt lighting LED is 50 V or less, the lighting LED is not turned on as a blocking state despite being forward biased.

3 is a graph schematically showing a relationship between voltage and current in an LED light driven by receiving AC power.

Referring to Figure 3 it can be seen the relationship of the voltage current with respect to the basic configuration of the AC power directly connected LED lighting device. When a full-wave rectified voltage is provided to the LED array in an AC power-connected LED lighting device, a flicker (blinking) corresponding to twice the commercial voltage frequency occurs, and the forward voltage of the LED array and Due to the dynamic resistance, a section in which the LED array does not light is generated, and thus fluctuations in the overall brightness appear periodically. FIG. 3A shows the current IL for the forward voltage Vf of the LED array when a full-wave rectified voltage V is provided to the LED array. In the direct-connected LED driving circuit, the current IL of the LED array begins to flow at a phase angle above the forward voltage Vf due to the influence of dynamic resistance near the forward voltage Vf, and thus starts to flow at a phase angle above the forward voltage Vf. It can be seen that a section d in which the array is not lit occurs. When such a direct-connected LED lighting device is configured by connecting a capacitor in parallel with the LED array as described in FIG. 1B, the current IL of the LED array is continuously charged and discharged by the capacitor as shown in FIG. 3B. As it flows to the ripple, the flicker phenomenon and the section in which the LED array is not lit can be removed.

4 is a graph schematically showing a voltage change when the LED lighting device including the ripple removing unit 500 using a capacitor is turned off.

As described above, when the ripple elimination unit 500 is configured by connecting a capacitor to a direct-type LED lighting device, it is possible to exert an effect of preventing the flicker by removing the ripple.

When the LED lighting circuit to which the capacitor is connected is turned off, the charge charged in the capacitor is discharged, and the voltage applied to the LED is gradually lowered. When the LED is not connected to the capacitor, the voltage gradually decreases with time as shown in the dotted graph in FIG. 4.

However, when the capacitor and the LED are connected, when the voltage across the LED decreases and reaches Vf of the LED (t1), the current is cut off due to the characteristics of the diode, and the voltage across the LED instantly increases again as the load disappears ( t2). In this way, as the voltage increases instantaneously, a flicker occurs in the LED. Such flickering is not a problem in general lighting, but in the case of broadcast lighting in which cameras and the like are used, it is necessary to prevent such flickering because fine flickering may affect the recording.

5 is a block diagram schematically showing the configuration of an LED lighting device according to an embodiment of the present invention.

Referring to Figure 5, the LED lighting device according to an embodiment of the present invention AC power supply 100, rectifier 200, DC / DC converter 300, LED control unit 400, ripple removal unit 500, blinking It includes a prevention unit 600 and the LED unit 700.

The AC power supply 100 supplies AC power. According to an embodiment of the present invention, the AC power supply 100 may receive AC power through an external outlet or the like and supply it to the LED lighting device.

The rectifying unit 200 converts AC power to DC power. According to an embodiment of the present invention, the rectifying unit 200 may be composed of a bridge diode or the like, and may convert the received AC power into a DC power by rectifying the received AC power.

The DC/DC converter 300 adjusts the driving voltage of the DC power. According to an embodiment of the present invention, the DC/DC converter 300 is composed of a linear regulator or a switching regulator to adjust the voltage of the DC power source to be suitable for a driving circuit.

The LED control unit 400 performs lighting, extinguishing, and illuminance control of the LED unit 700. The LED control unit 400 controls the LED unit 700 by controlling the power supplied to the LED unit 700. According to an embodiment of the present invention, the LED control unit 400 may control the lighting, extinguishing, and illuminance of the LED unit 700 by controlling the amount of current supplied to the LED unit 700.

The ripple removing unit 500 is located between the DC/DC converter and the LED unit to remove the ripple current of the power. The ripple removing unit 500 according to an embodiment of the present invention may remove ripple current of a power source by including one or more capacitor filters.

The flicker prevention unit 600 prevents flickering that occurs when the LED lights are turned off. Flicker Prevention Unit 600 As illustrated in FIG. 4, when a circuit including a capacitor is configured, flicker that may occur instantaneously when the LED light is turned off is prevented. The flicker prevention unit 600 according to an embodiment of the present invention includes a switching element that operates by receiving the lighting and extinguishing signals of the LED control unit 400 and bypasses the LED unit 700 when the LED lighting is turned off. By providing a passage that can be discharged, it is possible to prevent flicker occurring when the LED light is turned off.

The LED unit 700 is composed of one or more LEDs to receive illumination under control. The LED unit may include an LED cluster composed of a plurality of LEDs according to the purpose of the LED lighting and the like, and may be provided with a voltage applied thereto.

6 is a view schematically showing the configuration of an LED lighting device according to an embodiment of the present invention.

Referring to FIG. 6, a circuit diagram of a part of a configuration of an LED lighting device according to an embodiment of the present invention can be confirmed.

The rectifying unit 200 according to an embodiment of the present invention may be configured as a bridge diode (BD) as shown in FIG. 6. As described above, when the AC power is rectified through the bridge diode, flicker may occur as described in FIG. 1, and thus, flicker must be prevented through the ripple removal unit 500.

The ripple removing unit 500 according to an embodiment of the present invention may include one or more electrolytic capacitor filters that smooth the driving voltage and remove the ripple component from the current components flowing through the LED unit 700 as shown in FIG. 6. have.

The flicker preventing part 600 according to an embodiment of the present invention includes a first resistor R1 and a second resistor R2 connected to the contact points of the ripple removing part 500 and the LED part 700 as shown in FIG. ), the first switching element (Q1) and the first resistor (R1) and the ground, which is configured between the second resistor (R2) and the ground terminal and is turned on or off by receiving a control signal by the first resistor (R1). However, it may include a second switching element (Q2) that is configured between the receiving and receiving the control signal of the LED control unit 400 on or off.

The operation of the flicker prevention unit 600 according to an embodiment of the present invention is as follows.

When a voltage is applied to the LED unit 700 by the LED control unit 400 and is turned on, the second switching element Q2 composed of the NPN transistor inputs a high signal to the base so that current from the collector to the emitter flows. do.

At this time, a first resistor R1 is connected between the collector of the second switching element Q2 and the driving power. Since the collector of the second switching element Q2 is connected to the base of the first switching element Q1 composed of an NPN transistor, when a collector current flows through the second switching element Q2, the collector of the first switching element Q1 A low signal is input to the base to cut off the collector current.

Therefore, at this time, the flicker prevention unit 600 is connected to only the channel through the first resistor R1 from the driving power source to the ground point. At this time, since the resistance value of the first resistor R1 has a relatively large value, power consumed through the flicker prevention unit 600 is insignificant.

At this time, when the voltage is cut off and turned off by the LED control unit 400, the charge charged in the capacitor of the ripple removing unit 500 is discharged and a weak current flows to the LED unit 700. do.

When the LED is turned off by the control unit 400, a low signal is input to the base of the second switching element Q2, and the collector current is cut off. Therefore, a high signal is input to the base of the first switching element Q1 connected to the collector of the second switching element Q2, and a collector current flows through the first switching element Q1.

Therefore, at this time, since the flicker prevention unit 600 is connected to the ground point through a channel through the second resistor R2 from the driving power source, and the resistance value of the second resistor R2 has a relatively small value, the ripple The charge charged in the capacitor of the removal unit 500 is discharged through the flicker prevention unit 600 instead of the LED unit 700 to prevent flicker of the LED unit 700.

Referring to FIG. 6, the LED unit 700 according to an embodiment of the present invention may be configured by forming a cluster by connecting a plurality of light emitting diodes in series or in parallel.

7 is a view schematically showing the configuration of the LED unit 700 according to an embodiment of the present invention.

Referring to FIG. 7, the LED unit 700 according to an embodiment of the present invention is composed of one or a plurality of LEDs, and LED modules 720 to 740 that emit light by receiving power and are composed of one or a plurality of LEDs The power is supplied to the LED modules 720 to 740 according to the control signals of the preliminary LED module 750 and the LED control unit that emit light, and the LED modules 720 to 740 are checked for normal operation. If the module (720 to 740) does not operate normally includes an LED management unit 710 for applying power to the preliminary LED module 750.

In FIG. 7, the LED unit 700 is illustrated as having three LED modules and one spare LED module, but the present invention is not limited thereto, and may include one or more LED modules and one or more spare LED modules, respectively. .

The LED management unit 710 controls the lighting to operate by applying power to the LED modules 720 to 740 and the preliminary LED module 750. At this time, the LED management unit 710 controls the LED modules 720 to 740 to provide lighting by applying power to the LED modules 720 to 740 under normal circumstances.

If the LED modules 720 to 740 do not operate normally, the LED manager 710 applies power to the preliminary LED module 750 to operate in place of the LED modules 720 to 740.

As shown in FIG. 7, the LED unit 700 according to an embodiment of the present invention may include two or more LED modules 720 to 740, and the LED management unit 710 may include two or more LED modules 720 to 740) If it is determined that any one of the LED modules does not operate normally, power is supplied to the spare LED module 750 so that the lighting can continuously operate. In this way, if only one of the plurality of LED modules 720 to 740 does not operate normally, the preliminary LED module 750 may be operated in place of the corresponding LED module that does not operate normally.

8 is a block diagram schematically showing the internal configuration of the LED management unit according to an embodiment of the present invention.

8, the LED management unit 710 according to an embodiment of the present invention includes an LED module control unit 711, an LED module monitoring unit 712 and a preliminary LED module control unit 713.

The LED module control unit 711 applies power to the LED modules 720 to 740 according to the control signal of the LED control unit 400. According to an embodiment of the present invention, the LED module control unit 711 may be controlled by independently applying power to the plurality of LED modules 720 to 740. In this way, by controlling each LED module 720 to 740 independently, when one LED module does not operate normally, only the LED module can be cut off and the other LED modules can be operated continuously.

The LED module monitoring unit 712 determines whether the LED modules 720 to 740 are operating normally. The LED module monitoring unit 712 monitors the operation of the LED modules 720 to 740 through various methods to determine whether each of the LED modules 720 to 740 operates according to control by the LED control unit 400. Grasp.

The preliminary LED module control unit 713 applies power to the preliminary LED module 750 when the LED modules 720 to 740 do not operate normally. To this end, the preliminary LED module control unit 713 receives the monitoring result of the LED module monitoring unit 712 to apply power to the preliminary LED module 750 when an abnormality is found. Make it work.

Preferably, the LED management unit further includes an LED abnormality notification unit (not shown) that displays this to the user when the LED modules 720 to 740 do not operate normally, and the LED modules 720 to 740 do not operate normally. When the replacement is made with the spare LED module 750, the user can grasp the abnormality of the LED module and take measures such as replacing the LED module having the abnormality. The LED error notification unit (not shown) may display an error occurrence to the user by itself, or may transmit an error occurrence to the LED control unit 400 so that the LED control unit can display the error occurrence to the user.

In this way, the LED management unit 710 supplies LED power to the spare LED module 750 when any one of the LED modules 720 to 740 does not operate normally, so that the LED module can operate instead of the LED module that does not operate normally. The effect of displaying the light to the user so that the user can replace the LED module that does not normally operate after the module 720 to 740 is continuously supplied without causing problems such as a change in illumination of the lighting. Can exert.

9 is a block diagram schematically showing the configuration of an LED lighting device according to another embodiment of the present invention.

Referring to FIG. 9, the LED lighting device according to another embodiment of the present invention includes an AC power supply unit 100, a rectifying unit 200, a DC/DC converter 300, a first LED control unit 410, a second LED control unit 420, It includes a ripple removal unit 500, the flicker prevention unit 600 and the LED unit 700.

The AC power supply unit 100, rectification unit 200, DC/DC converter 300, ripple removal unit 500, flicker prevention unit 600 and LED unit 700 are the same as shown in FIG. Is omitted.

The first LED control unit 410 receives the illumination of the lighting and controls the power supplied to the LED module. The first LED control unit 410 performs the same role as the LED control unit 400 shown in FIG. 5, receives the illumination of the lighting, and controls the power supplied to the LED module based on the received illumination, thereby controlling the LED module. To control the illuminance. To this end, the first LED control unit 410 may transmit a control signal to the AC power unit 100, the rectification unit 200, or the DC/DC converter 300 to which power is supplied.

In this case, the first LED controller 410 may determine whether the received illuminance is equal to or greater than a predetermined threshold illuminance, and select and control the illuminance control method according to the illuminance.

The second LED control unit 420 adjusts the current supplied to the LED module under the control of the first LED control unit 410. The second LED control unit 420 controls the illuminance of the LED module by controlling the current supplied to the LED module by performing control according to the illuminance control method selected by the first LED control unit 410. To this end, the second LED control unit 420 is preferably configured to directly control the current supplied to the LED unit 700.

In addition, the second LED control unit 420 is preferably configured to receive a control signal connected to the first LED control unit in order to receive control of the first LED control unit 410.

10 is a block diagram schematically showing the internal configuration of the LED control unit according to an embodiment of the present invention.

Referring to Figure 10, the LED control unit 400 according to an embodiment of the present invention includes a first LED control unit 410 and a second LED control unit 42, the first LED control unit 410 is an illuminance input unit 411 and A control panel end portion 412 is included, and the second LED control portion 420 includes a PWM control portion 421 and a DC control portion 422.

The LED control unit 400 according to an embodiment of the present invention not only controls the lighting and extinguishing of the LED lights, but also performs illumination control.

In this case, the LED control unit 400 controls the illuminance of the LED unit 700 in a DC control method when the illuminance control value is equal to or greater than a predetermined threshold illuminance in performing the illuminance control. Controls the illuminance of 700.

The illuminance input unit 411 receives the illuminance of the LED light. The illuminance input unit 411 can receive the illuminance in an analog or digital manner, and when the received illuminance is 0, it can be recognized as the extinction of lighting and control the extinction.

The control panel end unit 412 determines whether the received illuminance is greater than or equal to a predetermined threshold illuminance. The critical illuminance may be preset and input according to characteristics of the LED unit 700 included in the LED lighting device. The control panel end portion 412 allows the PWM control unit 421 to be described later to control the illuminance when the received illuminance is less than the critical illuminance, and the DC control unit 422 to be described later controls the illuminance when the received illuminance is greater than or equal to the critical illuminance. .

The PWM control unit 421 controls the illuminance of the LED unit 700 in a PWM manner when the received illuminance is less than a predetermined threshold illuminance. The PWM control unit 421 controls the illuminance of the LED unit 700 by controlling the amount of current flowing to the LED unit 700 through a PWM signal of a constant voltage when the received illuminance is less than the critical illuminance.

More specifically, the PWM control unit 421 controls the illuminance of the LED unit 700 by adjusting the duty ratio based on the received illuminance while keeping the voltage supplied to the LED unit 700 constant.

The DC control unit 422 controls the illuminance of the LED unit 700 in a DC control method when the received illuminance is greater than or equal to a predetermined threshold illuminance. The DC controller 422 controls the illuminance of the LED unit 700 by controlling the amount of current flowing through the LED unit 700 by adjusting the voltage when the received illuminance is greater than or equal to the critical illuminance.

More specifically, the DC control unit 422 controls the illuminance of the LED unit 700 by adjusting the voltage supplied to the LED unit 700 based on the received illuminance.

11 is a graph schematically showing a control value according to the illumination control of the LED lighting according to an embodiment of the present invention.

Referring to FIG. 11, when the LED controller 400 according to an embodiment of the present invention performs illumination control, it is possible to check the voltage control value, duty ratio, and current amount for the illumination control value controlled.

As shown in FIG. 11A, when the illuminance control value is higher than the threshold illuminance X1, the higher the illuminance control value, the higher the voltage control value, and the lower the illuminance control value, the lower the voltage control value. Further, when the illuminance control value is lower than the threshold illuminance X1, the voltage control value is kept constant as the voltage control value when the threshold illuminance X1 is irrespective of the illuminance control value.

As shown in FIG. 11B, when the critical illuminance is less than X1, the lower the illumination control value, the lower the duty ratio, and the higher the illumination control value, the higher the duty ratio. At the critical illuminance X1, the duty ratio is 100%. In addition, since the DC control is performed when the critical illuminance is X1 or more, the duty ratio is maintained at 100%.

By performing PWM control when the critical illuminance is less than X1 and DC control when the critical illuminance is greater than X1, the LED control unit 400 sets the current supplied to the LED unit 700 to the illuminance control value as shown in FIG. 11C. Adjust the proportion to control the illuminance of the LED light.

12 is a block diagram schematically showing the configuration of an LED lighting device according to another embodiment of the present invention.

Referring to Figure 12, the LED lighting device according to another embodiment of the present invention AC power supply 100, rectifier 200, DC / DC converter 300, LED control unit 400, ripple removal unit 500, It includes a flicker prevention unit 600, an LED unit 700 and an auxiliary power supply unit 800.

The AC power supply unit 100, rectification unit 200, DC/DC converter 300, ripple removal unit 500, flicker prevention unit 600, and LED unit 700 are the same as shown in FIG. Is omitted.

The auxiliary power supply unit 800 may supply power to the LED lighting device. The auxiliary power supply unit 800 is under the control of the LED control unit when the LED lighting device does not supply power during normal operation, but when the AC power supply unit 100 or the rectification unit 200 has an abnormality and is unable to receive power. Supply power to the LED lighting device. Preferably, the auxiliary power supply unit 800 is provided with an independent power supply from the AC power supply unit 100, so that it can operate even when an abnormality occurs in the AC power supply unit 100.

The auxiliary power supply unit 800 according to an embodiment of the present invention temporarily supplies power in preparation for a case where power is not supplied from the AC power supply unit 100 so that the LED light can continuously provide lighting. Therefore, the auxiliary power supply unit 800 does not need to receive a constant power supply from the outside, such as the AC power supply unit 100, and may temporarily supply power by an internal battery or the like. Also, in this case, DC power may be supplied instead of AC power.

If, when the auxiliary power supply unit 800 includes an AC power source, it is preferable that the LED unit 700 receives a DC current by including a stop value therein.

The LED control unit 400 is the same as described above, but when power is not supplied from the AC power unit 100, LED power is controlled by receiving power from the auxiliary power unit 800.

The LED control unit 400 receives power from the AC power supply unit 100 and checks whether the AC power supply unit 100 and the rectifying unit 200 operate normally. As a result of the check, if an abnormality is found and power is not supplied from the AC power source 100, the power source is switched to receive power from the auxiliary power source.

Preferably, the LED control unit 400 further includes an abnormality notification unit (not shown) that displays this to the user when power is supplied from the auxiliary power unit 800 because power is not supplied from the AC power unit 100, Allow users to identify abnormalities in power supply and take action on it. More preferably, the abnormality notification unit receives the occurrence of an abnormality of the LED modules 720 to 740 of the LED unit 700 and displays it to the user so that the user can easily grasp the power supply or abnormality of the LED module.

To this end, the LED control unit 400 of the LED lighting apparatus according to an embodiment of the present invention supplies power from a power monitoring unit (not shown) and an AC power supply unit 100 to determine whether power is supplied from the AC power supply unit 100. If not received, it may include a power switch unit (not shown) that receives power from the auxiliary power unit.

As described above, the LED lighting device according to an embodiment of the present invention normally supplies power from AC power and provides lighting, and supplies power from auxiliary power even when AC power is not supplied due to failure or disconnection of the AC power. By receiving and providing lighting, it is possible to exert an effect of stably providing lighting regardless of a power supply abnormality in broadcasting using LED lighting.

According to an embodiment of the present invention, in an LED lighting driven by receiving an AC voltage, an effect capable of suppressing the occurrence of flicker can be exhibited.

According to an embodiment of the present invention, it is possible to exert an effect of preventing flicker that may occur when the LED light is turned off.

According to an embodiment of the present invention, when controlling the illuminance of the LED light, the PWM method is used when the light is less than the critical illuminance, and the DC control method is used to control the illuminance while suppressing flicker or flicker. .

According to an embodiment of the present invention, even if an abnormality occurs in the LED module, it is possible to exert the effect of providing continuous lighting by driving the preliminary LED module.

According to an embodiment of the present invention, even if an abnormality occurs in the AC power supply, the power can be supplied by the auxiliary power supply to exert the effect of providing continuous lighting.

As described above, although the embodiments have been described by a limited embodiment and drawings, those skilled in the art can make various modifications and variations from the above description. For example, the described techniques are performed in a different order than the described method, and/or the components of the described system, structure, device, circuit, etc. are combined or combined in a different form from the described method, or other components Alternatively, even if substituted or substituted by equivalents, appropriate results can be achieved. Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

Claims (10)

As an LED lighting device that prevents flicker,
LED unit consisting of one or more LEDs to provide lighting under control;
An AC power supply for supplying AC power;
A rectifying unit for converting AC power into DC power;
A DC/DC converter that controls the driving voltage of the DC power supply;
An LED control unit that performs lighting, lighting and illuminance control of the LED unit;
A ripple removing unit positioned between the DC/DC converter and the LED unit to remove ripple current of a power source; And
A flicker prevention unit that prevents flickering that occurs when the LED lighting is turned off; Including,
The ripple removal unit,
And at least one electrolytic capacitor filter that smooths the driving voltage and removes a ripple component among current components flowing in the LED unit.
One end of the electrolytic capacitor filter is electrically connected between the DC/DC converter and the LED unit, and the other end of the electrolytic capacitor filter is electrically connected to the ground terminal,
The flicker prevention unit,
A first resistor and a second resistor connected to the ripple removing portion and the LED portion;
A first switching element disposed between the second resistor and the ground terminal and including a transistor; And
And a second switching element disposed between the first resistor and the ground terminal and including a transistor.
The LED control unit is electrically connected to the base of the transistor of the second switching element,
One end of the second switching element is electrically connected to the base of the transistor of the first switching element,
The first resistance has a resistance value 10 times higher than the second resistance,
When the LED control unit is turned on, the LED control unit inputs a control signal to the base of the transistor of the second switching element so that current flows through the second switching element, so that no current flows through the first switching element. Become,
When the LED control unit is turned off, the LED control unit inputs a control signal to the base of the transistor of the second switching device so that current does not flow through the second switching device, and thus a current flows through the first switching device.
One end of the first resistor is electrically connected between the ripple removing portion and the LED portion, and the other end of the first resistor is electrically connected to the first switching element and the second switching element,
One end of the second resistor is electrically connected between the ripple removal unit and the LED unit, the other end of the second resistor is electrically connected to the first switching element, LED lighting device.
delete delete The method according to claim 1,
The LED unit,
LED module consisting of one or a plurality of LEDs and emits light by receiving power;
A preliminary LED module composed of one or a plurality of LEDs and receiving power and emitting light; And
An LED management unit that applies power to the LED module according to the control signal of the LED control unit, determines whether the LED module is operating normally, and applies power to the spare LED module when the LED module does not operate normally; LED lighting device comprising a.
The method according to claim 4,
The LED management unit,
An LED module control unit that applies power to the LED module according to the control signal of the LED control unit;
An LED module monitoring unit to determine whether the LED module is operating normally; And
A spare LED module control unit for applying power to the spare LED module when the LED module does not operate normally; LED lighting device comprising a.
The method according to claim 5,
The LED unit includes two or more LED modules,
The LED management unit is characterized in that if any one of the two or more LED modules do not operate normally, the LED lighting device, characterized in that for applying power to the spare LED module.
The method according to claim 1,
The LED control unit,
A first LED control unit for controlling the power supplied to the LED module receives the illumination of the illumination; And
A second LED control unit for adjusting the current supplied to the LED module according to the control of the first LED control unit; Including,
The first LED control unit,
An illuminance input unit that receives the illuminance of the LED light; And
A control panel unit for determining whether the received illuminance is equal to or greater than a predetermined threshold illuminance; Including,
The second LED control unit,
A PWM control unit that controls the illuminance of the LED unit in a PWM manner when the received illuminance is less than a predetermined threshold illuminance; And
A DC control unit that controls the illuminance of the LED unit using a DC control method when the received illuminance is equal to or greater than a predetermined threshold illuminance; LED lighting device comprising a.
The method according to claim 7,
The PWM control unit,
The LED lighting device characterized in that it controls the illuminance of the LED unit by adjusting the duty ratio based on the received illuminance while maintaining a constant voltage supplied to the LED unit.
The method according to claim 7,
The DC control unit,
LED lighting device, characterized in that to control the illuminance of the LED unit by adjusting the voltage supplied to the LED unit based on the received illumination.
The method according to claim 1,
The LED lighting device,
An auxiliary power supply unit capable of supplying power to the LED lighting device; Further comprising,
The LED control unit,
When it is not possible to receive power from the AC power supply, it is characterized in that it receives power from the auxiliary power supply to control the LED lighting, LED lighting device.

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