KR20050081938A - Inverter circuit for lcd - Google Patents

Inverter circuit for lcd Download PDF

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Publication number
KR20050081938A
KR20050081938A KR1020040010242A KR20040010242A KR20050081938A KR 20050081938 A KR20050081938 A KR 20050081938A KR 1020040010242 A KR1020040010242 A KR 1020040010242A KR 20040010242 A KR20040010242 A KR 20040010242A KR 20050081938 A KR20050081938 A KR 20050081938A
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South Korea
Prior art keywords
cold cathode
cathode tube
transformer
voltage
line
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KR1020040010242A
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Korean (ko)
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심재형
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엘지이노텍 주식회사
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Priority to KR1020040010242A priority Critical patent/KR20050081938A/en
Publication of KR20050081938A publication Critical patent/KR20050081938A/en

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
    • H05B41/14—Circuit arrangements
    • H05B41/26—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc
    • H05B41/28—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters
    • H05B41/282—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices
    • H05B41/285—Arrangements for protecting lamps or circuits against abnormal operating conditions
    • H05B41/2851—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the circuit against abnormal operating conditions
    • H05B41/2856—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the circuit against abnormal operating conditions against internal abnormal circuit conditions
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133602—Direct backlight
    • G02F1/133604—Direct backlight with lamps
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/3406—Control of illumination source
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/02—Manufacture of electrodes or electrode systems
    • H01J9/022—Manufacture of electrodes or electrode systems of cold cathodes

Abstract

본 발명은 LCD용 인버터 회로에 관한 것으로, 상세하게는 외부로부터 입력되는 교류 형태의 신호를 승압하여 고전압을 출력하는 트랜스포머와, 하이단이 상기 트랜스포머의 2차측 하이 라인에 연결되어 상기 트랜스포머로부터 출력되는 교류 고전압으로 점등되고, 로우단이 그라운드에 접지되는 냉음극관과, 상기 트랜스포머의 2차측 로우 라인에 연결되고, 상기 트랜스포머의 2차측 하이 라인에 연결되어 2차측 로우 라인의 전류와 2차측 하이 라인의 전압을 궤환받는 출력전류 조정회로와, 상기 트랜스포머의 2차측 하이 라인에 연결되어 상기 냉음극관으로 인가되는 전압을 센싱하고, 상기 냉음극관의 오픈 여부를 알리는 오픈램프 보호회로와, 직류 전압을 입력받아 구동되어 교류 형태의 신호를 상기 트랜스포머의 1차측으로 출력하고, 상기 냉음극관을 통해 흐르는 전류를 상기 출력전류 조정회로로부터 검출하여 출력을 조절하며, 상기 오픈램프 보호회로로부터 인가되는 전압을 궤환받아 상기 냉음극관의 오픈 여부를 검출하는 냉음극관 구동 IC를 포함하는 것을 특징으로 한다. 따라서 상기와 같이 구성된 본 발명에 따르면 냉음극관의 출력선이 단선되어도 점등을 유지하도록 하며, 출력 전류를 빠르게 안정화시키도록 하는데 있다.The present invention relates to an inverter circuit for LCD, and more particularly, a transformer for boosting an AC signal input from the outside and outputting a high voltage, and a high end connected to a secondary high line of the transformer and outputted from the transformer. It is connected to the secondary high line of the transformer and the cold cathode tube whose low end is grounded to the ground and the transformer is connected to the secondary high line of the transformer, and the current of the secondary low line and the secondary high line An output current control circuit for receiving a voltage, an open lamp protection circuit connected to a secondary high line of the transformer to sense a voltage applied to the cold cathode tube, and indicating whether the cold cathode tube is open, and a DC voltage is input. Driven to output an alternating current signal to the primary side of the transformer, the cold cathode tube And a cold cathode tube driving IC configured to detect an electric current flowing through the output current adjusting circuit to adjust an output, and detect whether the cold cathode tube is opened by receiving a voltage applied from the open lamp protection circuit. . Therefore, according to the present invention configured as described above to maintain the lighting even if the output line of the cold cathode tube is disconnected, and to stabilize the output current quickly.

Description

엘씨디용 인버터 회로{INVERTER CIRCUIT FOR LCD}Inverter Circuit for LCD {INVERTER CIRCUIT FOR LCD}

본 발명은 LCD용 인버터 회로에 관한 것이다.The present invention relates to an inverter circuit for LCD.

일반적으로 TFT LCD 백라이트용 인버터는 직류 전원을 교류 전원으로 변환 후 트랜스포머를 이용하여 고전압을 발생시켜 냉음극관을 구동하는 DC/AC 컨버터를 말한다.In general, an inverter for a TFT LCD backlight refers to a DC / AC converter that drives a cold cathode tube by generating a high voltage using a transformer after converting DC power to AC power.

도 1에 도시된 바와 같이 이러한 종래의 인버터(10)는 직류 전압을 입력받아 구동되어 교류 형태의 신호를 출력하고, 또한 하기에서 설명할 냉음극관(13)으로 인가되는 전압을 궤환받아 냉음극관(13)의 오픈 여부를 검출하며, 또 냉음극관(13)을 통해 흐르는 전류를 검출하여 출력을 조절하는 냉음극관 구동 IC(11)와, 냉음극관 구동 IC(11)로부터 출력되는 교류 형태의 신호를 승압하여 고전압을 출력하는 트랜스포머(12)와, 트랜스포머(12)로부터 출력되는 교류 고전압으로 점등되는 냉음극관(13)과, 냉음극관(13)을 통해 흐르는 전류를 검출하여 냉음극관 구동 IC(11)로 인가하는 출력전류 조정회로(14)와, 냉음극관(13)으로 인가되는 전압을 센싱하여 냉음극관(13)의 오픈 여부를 냉음극관 구동 IC(11)로 알리는 오픈램프 보호회로(15)로 구성된다.As shown in FIG. 1, the conventional inverter 10 is driven by receiving a DC voltage to output an AC signal, and also receives a voltage applied to the cold cathode tube 13 to be described below. 13) to detect the opening of the cold cathode tube 13, and to detect the current flowing through the cold cathode tube 13, and regulates the output of the cold cathode tube drive IC 11 and the AC signal output from the cold cathode tube drive IC (11) The cold cathode ray tube drive IC 11 which detects the electric current which flows through the transformer 12 which boosts and outputs a high voltage, the cold cathode tube 13 lighted by the alternating high voltage output from the transformer 12, and the cold cathode tube 13; The open current protection circuit 15 which senses whether the cold cathode tube 13 is opened by sensing the output current adjusting circuit 14 and the voltage applied to the cold cathode tube 13 to be applied to the cold cathode tube drive IC 11. It is composed.

이러한 인버터의 동작을 개략적으로 살펴보면, 인버터(10)의 냉음극관 구동 IC(11)는 정전압이 인가되면 펄스 형태의 교류 신호를 생성한 후, 이를 트랜스포머(12)로 출력하면, 트랜스포머(12)는 이를 고전압으로 승압한 후 냉음극관(13)으로 출력하여 냉음극관(13)을 점등시킨다. 이때 냉음극관(13)을 통과한 전류는 출력전류 조정회로(14)를 통해 냉음극관 구동 IC(11)로 입력되고, 이를 통해 냉음극관 구동 IC(11)는 냉음극관(13)의 상태를 확인한다. 여기에서 출력전류 조정회로(14)는 냉음극관(13)의 로우단에 연결된다.Referring to the operation of the inverter schematically, the cold cathode tube driving IC 11 of the inverter 10 generates an AC signal in the form of a pulse when a constant voltage is applied, and then outputs it to the transformer 12, the transformer 12 is The voltage is increased to high voltage and then output to the cold cathode tube 13 to light the cold cathode tube 13. At this time, the current passing through the cold cathode tube 13 is input to the cold cathode tube driving IC 11 through the output current adjusting circuit 14, through which the cold cathode tube driving IC 11 checks the state of the cold cathode tube 13 do. Here, the output current adjusting circuit 14 is connected to the low end of the cold cathode tube 13.

한편 냉음극관(13)이 오픈되면 오픈램프 보호회로(15)를 통해 입력되는 전압의 크기가 증가하기 때문에 냉음극관 구동 IC(11)는 냉음극관(13)의 오픈으로 인식하여 인버터(10)의 구동을 멈춘다. 여기에서 오픈램프 보호회로(15)는 트랜스포머(12)의 2차측 하이 라인에 연결된다.On the other hand, when the cold cathode tube 13 is opened, the magnitude of the voltage input through the open lamp protection circuit 15 increases, so the cold cathode tube driving IC 11 recognizes that the cold cathode tube 13 is open and thus, Stop running. Here, the open lamp protection circuit 15 is connected to the secondary high line of the transformer 12.

그러나 이러한 종래의 인버터는 냉음극관으로부터 전류 궤환을 받아 전류를 조절하기 때문에 냉음극관의 출력선이 단선되면 이와 동시에 냉음극관이 소등되고, 초기 구동시 안정화 시간이 상대적으로 긴 문제점이 있다.However, such a conventional inverter receives a current feedback from the cold cathode tube and adjusts the current, so that when the output line of the cold cathode tube is disconnected, the cold cathode tube is turned off at the same time, and the stabilization time is relatively long during initial operation.

따라서 본 발명의 목적은 상기와 같은 문제점을 해결하기 위한 것으로, 냉음극관의 출력선이 단선되어도 점등을 유지하도록 하며, 출력 전류를 빠르게 안정화시키도록 하는데 있다.Therefore, an object of the present invention is to solve the above problems, to maintain the lighting even if the output line of the cold cathode tube is disconnected, and to stabilize the output current quickly.

상기와 같은 목적을 달성하기 위한 본 발명의 특징은,Features of the present invention for achieving the above object,

인버터에 있어서,In the inverter,

외부로부터 입력되는 교류 형태의 신호를 승압하여 고전압을 출력하는 트랜스포머와,A transformer for boosting an AC signal input from the outside and outputting a high voltage;

하이단이 상기 트랜스포머의 2차측 하이 라인에 연결되어 상기 트랜스포머로부터 출력되는 교류 고전압으로 점등되고, 로우단이 그라운드에 접지되는 냉음극관과,A cold cathode tube whose high end is connected to the secondary high line of the transformer and is lit by an AC high voltage output from the transformer, and whose low end is grounded to ground;

상기 트랜스포머의 2차측 로우 라인에 연결되고, 상기 트랜스포머의 2차측 하이 라인에 연결되어 2차측 로우 라인의 전류와 2차측 하이 라인의 전압을 궤환받는 출력전류 조정회로와,An output current adjustment circuit connected to the secondary low line of the transformer and connected to the secondary high line of the transformer to receive the current of the secondary low line and the voltage of the secondary high line;

상기 트랜스포머의 2차측 하이 라인에 연결되어 상기 냉음극관으로 인가되는 전압을 센싱하고, 상기 냉음극관의 오픈 여부를 알리는 오픈램프 보호회로와,An open lamp protection circuit connected to the secondary high line of the transformer for sensing a voltage applied to the cold cathode tube and indicating whether the cold cathode tube is open;

직류 전압을 입력받아 구동되어 교류 형태의 신호를 상기 트랜스포머의 1차측으로 출력하고, 상기 냉음극관을 통해 흐르는 전류를 상기 출력전류 조정회로로부터 검출하여 출력을 조절하며, 상기 오픈램프 보호회로로부터 인가되는 전압을 궤환받아 상기 냉음극관의 오픈 여부를 검출하는 냉음극관 구동 IC를 포함하는 것을 특징으로 한다.It is driven by receiving a DC voltage and outputs an AC signal to the primary side of the transformer, and detects the current flowing through the cold cathode tube from the output current adjusting circuit to regulate the output and is applied from the open lamp protection circuit. It characterized in that it comprises a cold cathode tube driving IC for receiving a voltage feedback to detect whether the cold cathode tube is open.

여기에서 상기 출력전류 조정회로는,Here, the output current adjustment circuit,

2차측 로우 라인에 연결되고, 상기 트랜스포머의 2차측 하이 라인에 연결되어 2차측 로우 라인의 전류와 2차측 하이 라인의 전압을 궤환받아 상기 냉음극관으로 흐르는 전류를 검출하여 상기 냉음극관의 초기 안정화 시간을 빠르게 갖는다.An initial stabilization time of the cold cathode tube connected to a secondary low line and connected to a secondary high line of the transformer to detect a current flowing through the cold cathode tube by receiving a current of the secondary low line and a voltage of the secondary high line; Have fast.

이하, 본 발명에 의한 LCD용 인버터 회로의 구성을 도 2를 참조하여 상세하게 설명하기로 한다.Hereinafter, the configuration of the inverter inverter circuit for LCD according to the present invention will be described in detail with reference to FIG.

도 2는 본 발명에 따른 LCD용 인버터 회로의 구성을 나타낸 블록도이다.2 is a block diagram showing the configuration of an inverter circuit for an LCD according to the present invention.

도 2를 참조하면, 본 발명에 따른 LCD용 인버터 회로(100)는, 트랜스포머(110)와, 냉음극관(120)과, 출력전류 조정회로(130)와, 오픈램프 보호회로(140)와, 냉음극관 구동 IC(150)로 구성된다.2, the LCD inverter circuit 100 according to the present invention, the transformer 110, the cold cathode tube 120, the output current adjustment circuit 130, the open lamp protection circuit 140, It consists of the cold cathode tube drive IC 150.

트랜스포머(110)는 하기에서 설명할 냉음극관 구동 IC(150)로부터 입력되는 교류 형태의 신호를 승압하여 고전압을 출력한다.The transformer 110 boosts a signal of an AC type input from the cold cathode tube driving IC 150 to be described below, and outputs a high voltage.

냉음극관(120)은 트랜스포머(110)로부터 출력되는 교류 고전압으로 점등되도록 하이단이 트랜스포머(110)의 2차측 하이 라인에 연결되고, 로우단이 그라운드에 접지된다.The cold cathode tube 120 has a high end connected to the secondary high line of the transformer 110 so that the cold cathode tube 120 is turned on by an AC high voltage output from the transformer 110, and the low end is grounded to ground.

출력전류 조정회로(130)는 냉음극관(120)으로 흐르는 전류를 검출하고, 냉음극관(120)의 초기 안정화시간을 빠르게 갖도록 트랜스포머(110)의 2차측 로우 라인에 연결되고, 트랜스포머(110)의 2차측 하이 라인에 연결되어 2차측 로우 라인의 전류와 2차측 하이 라인의 전압을 궤환받는다.The output current adjusting circuit 130 detects a current flowing in the cold cathode tube 120, is connected to the secondary low line of the transformer 110 to have an initial stabilization time of the cold cathode tube 120, and the It is connected to the secondary high line and receives the current of the secondary low line and the voltage of the secondary high line.

오픈램프 보호회로(140)는 냉음극관(120)으로 인가되는 전압을 센싱하여 냉음극관(120)의 오픈 여부를 알리도록 트랜스포머(110)의 2차측 하이 라인에 연결된다. 여기에서 트랜스포머(110)의 2차측 하이 라인에는 직류를 제거하기 위한 궤환 콘덴서(C1)가 연결되고, 출력전류 조정회로(130)는 궤환 콘덴서(C1)의 후단에 연결된다.The open lamp protection circuit 140 is connected to the secondary high line of the transformer 110 to sense whether the cold cathode tube 120 is open by sensing a voltage applied to the cold cathode tube 120. Here, a feedback capacitor C1 for removing direct current is connected to the secondary high line of the transformer 110, and an output current adjusting circuit 130 is connected to a rear end of the feedback capacitor C1.

냉음극관 구동 IC(150)는 직류 전압을 입력받아 구동되어 교류 형태의 신호를 트랜스포머(110)의 1차측으로 출력하고, 냉음극관(120)을 통해 흐르는 전류를 출력전류 조정회로(130)로부터 검출하여 출력을 조절하며, 오픈램프 보호회로(140)로부터 인가되는 전압을 궤환받아 냉음극관(120)의 오픈 여부를 검출한다.The cold cathode tube driving IC 150 is driven by receiving a DC voltage to output an AC signal to the primary side of the transformer 110, and detects a current flowing through the cold cathode tube 120 from the output current adjusting circuit 130. By adjusting the output, it receives a voltage applied from the open lamp protection circuit 140 to detect whether the cold cathode tube 120 is open.

이하 본 발명에 따른 LCD용 인버터 회로의 동작을 도 2를 참조하여 상세하게 설명하면 다음과 같다.Hereinafter, the operation of the LCD inverter circuit according to the present invention will be described in detail with reference to FIG. 2.

먼저 냉음극관 구동 IC(150)는 정전압이 인가되면 펄스 형태의 교류 신호를 생성한 후, 이를 트랜스포머(110)로 출력하면, 트랜스포머(110)는 이를 고전압으로 승압한 후 냉음극관(120)으로 출력하여 냉음극관(120)을 점등시킨다. 이때 트랜스포머(110)의 2차측 하이 라인을 통해 냉음극관(120)으로 인가되는 전류는 출력전류 조정회로(130)를 통해 냉음극관 구동 IC(150)로 입력되고, 냉음극관 구동 IC(150)는 이를 이용하여 냉음극관(120)의 상태를 확인한다.First, the cold cathode tube driving IC 150 generates an AC signal in the form of a pulse when a constant voltage is applied, and then outputs it to the transformer 110. The transformer 110 boosts it to a high voltage and then outputs it to the cold cathode tube 120. To turn on the cold cathode tube 120. At this time, the current applied to the cold cathode tube 120 through the secondary high line of the transformer 110 is input to the cold cathode tube driving IC 150 through the output current adjustment circuit 130, the cold cathode tube driving IC 150 is Check the state of the cold cathode tube 120 using this.

그리고 냉음극관(120)이 오픈되면 오픈램프 보호회로(140)는 트랜스포머(110)의 2차측 하이 라인을 통해 출력되는 전압의 크기를 검출하여 이를 냉음극관 구동 IC(150)로 입력시키면, 냉음극관 구동 IC(150)는 전압의 크기를 이용하여 냉음극관(120)의 오픈여부 인식하여 오픈된 경우 구동을 멈춘다.When the cold cathode tube 120 is opened, the open lamp protection circuit 140 detects the magnitude of the voltage output through the secondary high line of the transformer 110 and inputs it to the cold cathode tube driving IC 150. The driving IC 150 stops driving when it is opened by recognizing whether the cold cathode tube 120 is opened by using the magnitude of the voltage.

한편 출력전류 조정회로(130)는 트랜스포머(110)의 2차측 로우 라인을 통해 전류를 궤환받고, 트랜스포머(110)의 2차측 하이 라인을 통해 전압을 궤환받는다.On the other hand, the output current adjusting circuit 130 is fed back current through the secondary low line of the transformer 110, the voltage is fed back via the secondary high line of the transformer 110.

인버터를 초기 구동시에는 냉음극관(120)의 임피던스가 크고, 냉음극관(120)이 열을 받으면 임피던스가 작아져 안정화되는 데, 트랜스포머(110)의 2차측 하이 라인을 통해 출력전류 조정회로(130)에서 전압을 궤환받으면 출력 전류의 안정화 시간이 길어지고, 이를 보상하기 위하여 트랜스포머(110)의 2차측 로우 라인을 통해 출력전류 조정회로(130)에서 전류를 궤환받아 빠른 시간에 출력 전류를 안정화시킨다.When the inverter is initially driven, the impedance of the cold cathode tube 120 is large and the impedance of the cold cathode tube 120 is reduced when the cold cathode tube 120 receives heat, thereby stabilizing. The output current adjusting circuit 130 is controlled through the secondary high line of the transformer 110. When the voltage is fed back, the stabilization time of the output current becomes long, and in order to compensate for this, the current is fed back from the output current adjusting circuit 130 through the secondary low line of the transformer 110 to stabilize the output current in a short time. .

또한 냉음극관(120)의 로우단을 그라운드에 접지시킴으로써 냉음극관(120)의 출력선이 단선되어도 점등을 유지한다.In addition, the low end of the cold cathode tube 120 is grounded to maintain grounding even when the output line of the cold cathode tube 120 is disconnected.

이상에서 설명한 바와 같이 본 발명에 따른 LCD용 인버터 회로에 의하면, 냉음극관의 출력선이 단선되어도 점등을 유지하도록 하며, 출력 전류를 빠르게 안정화시킬 수 있다.As described above, according to the LCD inverter circuit according to the present invention, the output current of the cold cathode tube is maintained even when the output line is disconnected, and the output current can be stabilized quickly.

도 1은 종래 인버터의 구성을 나타낸 블록도1 is a block diagram showing the configuration of a conventional inverter

도 2는 본 발명에 따른 LCD용 인버터 회로의 구성을 나타낸 블록도2 is a block diagram showing the configuration of an inverter circuit for an LCD according to the present invention.

<도면중 주요부분에 대한 부호의 설명><Description of the symbols for the main parts of the drawings>

110 : 트랜스포머 120 : 냉음극관110: transformer 120: cold cathode tube

130 : 출력전류 조정회로 140 : 오픈램프 보호회로130: output current adjustment circuit 140: open lamp protection circuit

150 : 냉음극관 구동 IC150: cold cathode tube driving IC

Claims (2)

인버터에 있어서,In the inverter, 외부로부터 입력되는 교류 형태의 신호를 승압하여 고전압을 출력하는 트랜스포머와,A transformer for boosting an AC signal input from the outside and outputting a high voltage; 하이단이 상기 트랜스포머의 2차측 하이 라인에 연결되어 상기 트랜스포머로부터 출력되는 교류 고전압으로 점등되고, 로우단이 그라운드에 접지되는 냉음극관과,A cold cathode tube whose high end is connected to the secondary high line of the transformer and is lit by an AC high voltage output from the transformer, and whose low end is grounded to ground; 상기 트랜스포머의 2차측 로우 라인에 연결되고, 상기 트랜스포머의 2차측 하이 라인에 연결되어 2차측 로우 라인의 전류와 2차측 하이 라인의 전압을 궤환받는 출력전류 조정회로와,An output current adjustment circuit connected to the secondary low line of the transformer and connected to the secondary high line of the transformer to receive the current of the secondary low line and the voltage of the secondary high line; 상기 트랜스포머의 2차측 하이 라인에 연결되어 상기 냉음극관으로 인가되는 전압을 센싱하고, 상기 냉음극관의 오픈 여부를 알리는 오픈램프 보호회로와,An open lamp protection circuit connected to the secondary high line of the transformer for sensing a voltage applied to the cold cathode tube and indicating whether the cold cathode tube is open; 직류 전압을 입력받아 구동되어 교류 형태의 신호를 상기 트랜스포머의 1차측으로 출력하고, 상기 냉음극관을 통해 흐르는 전류를 상기 출력전류 조정회로로부터 검출하여 출력을 조절하며, 상기 오픈램프 보호회로로부터 인가되는 전압을 궤환받아 상기 냉음극관의 오픈 여부를 검출하는 냉음극관 구동 IC를 포함하는 것을 특징으로 하는 LCD용 인버터 회로.It is driven by receiving a DC voltage and outputs an AC signal to the primary side of the transformer, and detects the current flowing through the cold cathode tube from the output current adjusting circuit to regulate the output and is applied from the open lamp protection circuit. Inverter circuit for LCD comprising a cold cathode tube driving IC for receiving a voltage feedback to detect whether the cold cathode tube is open. 제 1항에 있어서,The method of claim 1, 상기 출력전류 조정회로는,The output current adjustment circuit, 2차측 로우 라인에 연결되고, 상기 트랜스포머의 2차측 하이 라인에 연결되어 2차측 로우 라인의 전류와 2차측 하이 라인의 전압을 궤환받아 상기 냉음극관으로 흐르는 전류를 검출하여 상기 냉음극관의 초기 안정화 시간을 빠르게 갖는 것을 특징으로 하는 LCD용 인버터 회로.An initial stabilization time of the cold cathode tube connected to a secondary low line and connected to a secondary high line of the transformer to detect a current flowing through the cold cathode tube by receiving a current of the secondary low line and a voltage of the secondary high line; Inverter circuit for LCD, characterized in that having a fast.
KR1020040010242A 2004-02-17 2004-02-17 Inverter circuit for lcd KR20050081938A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100813408B1 (en) * 2006-11-15 2008-03-12 엘지이노텍 주식회사 Inverter circuit for lcd backlight
KR101461115B1 (en) * 2007-10-31 2014-11-13 삼성디스플레이 주식회사 Backlight apparatus and liquid crystal display apparatus having the same

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100813408B1 (en) * 2006-11-15 2008-03-12 엘지이노텍 주식회사 Inverter circuit for lcd backlight
KR101461115B1 (en) * 2007-10-31 2014-11-13 삼성디스플레이 주식회사 Backlight apparatus and liquid crystal display apparatus having the same
US8896515B2 (en) 2007-10-31 2014-11-25 Samsung Display Co., Ltd. Backlight apparatus and liquid crystal display apparatus having the same

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