KR102302419B1 - Led lighting device capable of recognizing led faults and complementing there of - Google Patents

Abstract

Disclosed is an LED lighting device capable of recognizing a failure of an LED and complementing the same. According to the present invention, it is possible to recognize a failure due to short or opening of a lighting device using an LED, and to compensate the same to control the same. The LED lighting device includes: an LED array (110) which is composed of a plurality of LEDs; and a current control unit (120) which is connected to the LED array (110), includes a comparator (121), a shift register (122), a power transistor array unit (123) composed of a plurality of unit power transistors, and a resistor (124), and operates to control the current (I_(LED)) of the LED array (110).

Description

LED lighting device capable of recognizing LED failures and supplementing them

The present invention relates to an LED lighting device capable of recognizing a failure of an LED and supplementing it, and more particularly, recognizing a failure due to a short or open of a lighting device using an LED and controlling it by supplementing it. It relates to LED lighting devices capable of recognizing possible LED failures and supplementing them.

In general, as a configuration for regulating the current of the LED array structure, an analog current regulator is configured.

The analog current regulator is composed of an amplifier (AMP), a power transistor (Mp), and a resistor (R) to adjust the current of the LED array.

1 is an exemplary view showing an electrical configuration of a lighting device having an LED failure recognition circuit according to the prior art.

Referring to FIG. 1 , a lighting device 10 having an LED failure recognition circuit according to the prior art includes an LED array 11 in which LED modules 11a and 11b composed of a plurality of LEDs are connected in series, and an amplifier 12a. , comprising an analog current regulator 12 composed of a power transistor 12b and a resistor 12c, and adjusting the current of the LED array 11 by the analog current regulator 12 ((I _LED = I _{LED) ,1} =I _LED,N ).

However, since a plurality of LED modules 11a and 11b are connected in series, a high input voltage (V _IN = V _LED,1 + ... + V _LED,N ) is required.

In addition, in the LED array 11 connected in series, when even one LED module 11a, 11b is opened, the flow of current is blocked and the entire LED array 11 is turned off.

2 is another exemplary view showing the electrical configuration of a lighting device having an LED failure recognition circuit according to the prior art.

Referring to FIG. 2, a lighting device according to the prior art includes an LED array 21 to which LED modules 21a and 21b composed of a plurality of LEDs are connected in series, an amplifier 22a, a power transistor 22b, and a resistor 22c. ), the bypass unit 23 composed of the analog current regulator 22, the bypass transistors 23a and 23b respectively connected to the individual LED modules 21a, 21b, and the operation of the bypass unit 23 It includes a control unit 24 for controlling, and bypasses the failed LED modules (21a, 21b) when the LED modules (21a, 21b) are opened so that the remaining normally operating LED modules can be operated.

However, the lighting device of FIG. 2 has a problem in that the control operation for turning on/off the individual bypass transistors 23a and 23b and the level of the gate voltage are different, so it is difficult to implement this, and the circuit is complicated.

Korea Patent Publication No. 10-1751190 (Title of the invention: LED backlight and liquid crystal display)

In order to solve this problem, the present invention recognizes a failure due to a short or open of a lighting device using an LED and compensates and controls the failure of the LED capable of recognizing and compensating for the LED lighting device. intended to provide

In order to achieve the above object, an embodiment of the present invention provides an LED lighting device capable of recognizing a failure of an LED and complementing it, comprising: an LED array composed of a plurality of LEDs; and a power transistor array unit connected to the LED array and comprising a comparator, a shift register, a plurality of unit power transistors, and a resistor, wherein according to a comparison result of the reference voltage of the comparator and the voltage applied to the resistor, A current control unit operable to adjust the current of the LED array by controlling the number of unit power transistors turned on in the power transistor array unit to increase or decrease through an operation; including, wherein the current control unit is an LED array and a Schmitt trigger unit operable to turn off all unit power transistors of the power transistor array unit by operating the shift register in response to detecting the occurrence of a short circuit based on the short circuit voltage.

In addition, the Schmitt trigger unit according to the above embodiment detects the short-circuit voltage of the LED array and outputs a constant output value so that all the values of the shift register become the same value, but a short circuit occurs in LEDs of an arbitrary number or more among the LEDs of the LED array. When the short-circuit voltage increases, the output value is switched and input to the shift register.

In addition, it is connected to the output terminal of the shift register according to the embodiment, and when the voltage applied to the resistor converges to the ground voltage as the LED array is opened, the output signal of the shift register is switched to signal a failure caused by the opening of the LED array. It characterized in that it includes; a failure signal output unit for outputting.

The present invention has an advantage in that it is possible to recognize a failure caused by a short or open of a lighting device using an LED and to control it by supplementing it.

1 is an exemplary view showing an electrical configuration of a lighting device having an LED failure recognition circuit according to the prior art.
2 is another exemplary view showing the electrical configuration of a lighting device having an LED failure recognition circuit according to the prior art.
3 is a block diagram illustrating an electrical configuration of an LED lighting device capable of recognizing a failure of an LED and supplementing it according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments of the present invention and the accompanying drawings.

Prior to describing the specific contents for carrying out the present invention, it should be noted that components not directly related to the technical gist of the present invention are omitted within the scope of not disturbing the technical gist of the present invention.

In addition, the terms or words used in the present specification and claims have meanings and concepts consistent with the technical idea of the invention based on the principle that the inventor can define the concept of an appropriate term to best describe his invention. should be interpreted as

In the present specification, the expression that a part "includes" a certain element does not exclude other elements, but means that other elements may be further included.

Also, terms such as “… unit”, “… group”, and “… module” mean a unit that processes at least one function or operation, which may be divided into hardware, software, or a combination of the two.

In addition, the term "at least one" is defined as a term including the singular and the plural, and even if the term "at least one" does not exist, each element may exist in the singular or plural, and may mean the singular or plural. will be self-evident.

In addition, that each component is provided in singular or plural may be changed according to an embodiment.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the LED lighting device capable of recognizing a failure of the LED and supplementing it according to an embodiment of the present invention will be described in detail.

3 is a block diagram showing an electrical configuration of an LED lighting device capable of recognizing a failure of an LED and supplementing it according to an embodiment of the present invention.

Referring to FIG. 3 , the lighting device 100 according to an embodiment of the present invention includes an LED array 110 and a current controller 120 .

The LED array 110 is made of a plurality of LEDs, the LEDs may be connected in series or connected in parallel to each other.

The current controller 120 is connected to the LED array 110 _{to control the current (I LED} ) of the LED array 110 to be adjusted, and when a failure of the LED array 110 occurs, a failure occurs by detecting it As a configuration for outputting a signal, a comparator 121 , a shift register 122 , a power transistor array unit 123 , a resistor 124 , a Schmitt trigger unit 125 , and a failure signal output unit 126 . is comprised of

The comparator 121, as a comparator, compares the reference voltage V _REF and the voltage V _R across the resistor 124 and outputs a signal indicating the larger one, and the voltage V _R of The comparison result signal according to the change is input to the shift register 122 .

The shift register 122 is configured to output an operation signal for on/off control of the power transistor array unit 123 in response to the amount of current of the LED array 110 . The input terminal of the shift register 122 is a comparator 121 . ), and the output terminal of the shift register 122 is connected to the input side of the power transistor array unit 123 .

In addition, the shift register 122 shifts (shifts) all bits by one position at every clock (CLK) period according to a comparison result signal input from the comparator 121, and the shift register 122 is a right shift register or It can be configured as a bidirectional shift register.

In addition, the shift register 122 receives the power through the operation of the shift register 122 according to a comparison result _{between the reference voltage V REF of the comparator 121 and the voltage V R} applied to the resistor 124 . The number of unit power transistors turned on in the transistor array unit 123 is controlled to increase or decrease.

The power transistor array unit 123 may be connected to the shift register 122 and include a predetermined number of unit power transistors corresponding to the amount of current of the LED array 110 .

In addition, the power transistor array unit 123 is controlled to increase or decrease the number of unit power transistors turned on in the power transistor array unit 123 through the operation of the shift register 122, so that the LED array 110 is The current (I _LED ) operates to be regulated.

One side of the resistor 124 is connected to the power transistor array unit 123 and the other side is connected to the ground, so that the voltage V _R according to the amount of current between the LED array 110 and the power transistor array unit 123 is a comparator ( 121) to be entered.

The Schmitt trigger unit 125 is connected to the output terminal of the LED array 110 , and detects the occurrence of a short circuit based on the short _{circuit voltage V Detect of the LED array 110 .}

In addition, when a short circuit occurs in the LED array 110 , the Schmitt trigger unit 125 operates the shift register 122 to turn off all unit power transistors of the power transistor array unit 123 .

That is, the Schmitt trigger unit 125 switches the output value D _Short when a short circuit occurs in more than a certain number of LEDs among the LEDs of the LED array 110 and the short circuit voltage V _Detect increases, and shifts the output value D Short . It is input so that all values (D[1:N]) of the register 122 are set to '1'.

When the LED array 110 operates normally, the short-circuit voltage V _Detect is maintained at a low voltage, and its output value D _Short becomes '0'.

In addition, when the LEDs of the LED array 110 are short-circuited, the short-circuit voltage V _Detect increases. When more than a certain number of LEDs are short-circuited, the output value D _Short becomes '1' and the shift register 122 . By turning off all unit power transistors of the power transistor array unit 123, it is possible to prevent the power transistors from being overheated or damaged.

The failure signal output unit 126 is connected to an output terminal of the shift register 122, and when the voltage V _R applied to the resistor 124 converges to the ground voltage as the LED array 110 is opened, the shift register The output signal of (122) is switched so that a fault signal is output.

That is, when an open occurs in the LED array 110 rather than a short circuit in the failure signal output unit 126 , since the I _LED no longer flows, V _R maintains a value close to the ground voltage.

Accordingly, while V _R is _{kept smaller than V REF} , the comparator 121 and the shift register 122 continue to turn on the unit power transistors of the power transistor array unit 123 in order to increase _{V R .}

Since the LED array 110 remains open even when the shift register 122 continuously turns on all the unit power transistors sequentially (D[1:N] = 0, 0 ... 0), V _R is the ground voltage It maintains a value close to , and eventually D[N+1] becomes '0'.

Also, when D[N+1] becomes '0', D _Open When the value becomes '1', it is possible to detect a case in which the LED array 110 is opened, so that a failure can be recognized and a failure occurrence signal can be output accordingly.

_{In addition, according to the comparison result of the reference voltage (V REF} ) of the comparator 121 and the voltage (V _R ) applied to the resistor 124 , the current controller 120 determines whether an input value of '1' or '0' is It is input to the shift register 122 , and the input value is shifted at every clock cycle and input to the power transistor array unit 123 .

That is, when any LED among the LEDs of the LED array 110 is short-circuited or opened, the voltage V _R applied to the resistor 124 is changed to cause a change in the output value of the comparator 121 , and the changed output value is By reflecting in the power transistor array unit 123 to turn on the unit power transistor, the current (I _LED ) of the LED array 110 is adjusted.

In addition, when the occurrence of LED failure in the LED array 110 increases, the current control unit 120 adjusts the output value of the comparator 121 according to the change in the _{voltage V R applied to the resistor 124 to change the shift register.} Reflected in 122 , the shift register 122 operates to increase or decrease the number of unit power transistors turned on in the power transistor array unit 123 to adjust _{the current I LED of the LED array 110 .} operate as much as possible.

Accordingly, it is possible to recognize a failure due to a short or open of a lighting device using an LED and to control it by supplementing it.

As described above, although described with reference to the preferred embodiment of the present invention, those skilled in the art can variously modify and change the present invention within the scope without departing from the spirit and scope of the present invention described in the claims below. You will understand that it can be done.

In addition, the reference numbers described in the claims of the present invention are only described for clarity and convenience of explanation, and are not limited thereto, and in the process of describing the embodiment, the thickness of the lines shown in the drawings or the size of components, etc. may be exaggerated for clarity and convenience of explanation.

In addition, the above-mentioned terms are terms defined in consideration of functions in the present invention, which may vary depending on the intention or custom of the user or operator, so the interpretation of these terms should be made based on the content throughout this specification. .

In addition, even if it is not explicitly shown or described, a person of ordinary skill in the art to which the present invention pertains can make various modifications including the technical idea according to the present invention from the description of the present invention. Obviously, this still falls within the scope of the present invention.

In addition, the above embodiments described with reference to the accompanying drawings have been described for the purpose of explaining the present invention, and the scope of the present invention is not limited to these embodiments.

100: LED lighting device
110: LED module
120: current control unit
121: comparator
122: shift register
123: power transistor array unit
124 : resistance
125: Schmitt trigger part
126: fault signal output unit

Claims (3)

LED array 110 made of a plurality of LEDs; and
It is connected to the LED array 110 and includes a comparator 121, a shift register 122, a power transistor array unit 123 composed of a plurality of unit power transistors, and a resistor 124,
According to the comparison result of the reference voltage V _{REF of the comparator 121 and the voltage V R} applied to the resistor 124 , the power transistor array unit 123 is turned on through the operation of the shift register 122 . A current control unit 120 that operates so that _{the current (I LED} ) of the LED array 110 is adjusted by controlling the number of unit power transistors to be increased or decreased.
As the current controller 120 detects the occurrence of a short circuit based on the short _{circuit voltage (V Detect) of the LED array 110,}
a Schmitt trigger unit 125 that operates the shift register 122 to turn off all unit power transistors of the power transistor array unit 123;
_{The Schmitt trigger unit 125 detects the short-circuit voltage (V Detect} ) of the LED array 110 and _{outputs a predetermined output value (D Short} ) so that all values of the shift register 122 become the same value,
_{When the short circuit voltage (V Detect} ) increases due to a short circuit in more than a certain number of LEDs among the LEDs of the LED array 110 , the output value D _Short is switched and inputted to the shift register 122 . LED lighting device capable of recognizing LED failures and supplementing them. delete The method of claim 1,
_{When the voltage V R} connected to the output terminal of the shift register 122 and applied to the resistor 124 converges to the ground voltage as the LED array 110 is opened,
A failure signal output unit 126 for outputting a failure occurrence signal due to the opening of the LED array 110 by switching the output signal of the shift register 122; Possible LED lighting devices.

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