M309184 八、新型說明： 【新型所屬之技術領域】 本創作係關於一種液晶面板背光裝置之回授與保護電 路，尤指將電路予以積體電路化設計，以簡化傳統以各別 ^ 元件組成之回授與保護電路，減少電路元件佈局所佔的面 - 積並降低整體成本者。 【先前技術】 液晶面板背光裝置係使用一高頻交流正弦波電源供應 冷陰極螢光燈管（CCFL)發光之能量，因此使用直流轉交 肌換流電路來達成能量轉換的目的。習知的交換式換流器 (DC/AC lnverter )由於成本考量皆使用一顆交換式換流器 專用的脈波寬度調整器（PWM Controller)來控制整個換流 電路提供全數冷陰極螢光燈管發光產生足夠先源。但是一 顆脈波寬度調整器只有—個電壓回授輸人端、_個電流回 授輸入端與-個異常狀態保護控制輪人端，液晶= 裝置必須能夠整合每-冷陰極螢光燈管的電壓與電^入 汛唬，再輸出單一的電壓回授訊息1•刖 寬度調整控制器的輸人端，同時另===號到脈波 )有::二陰極榮光燈管發生短路(人體觸碰 )的一 “形’以輸出異常狀態保護訊號 (未‘，、、占- 制器，_背光裝置所有輸出，以 ·讀調整控 常持續而損壞電路元件或造成人體觸二产二：路不致因異 式皆以各別元件組成此一鱼 目蚋習知方 保錢路，^組成元件 5 M309184 眾多且複雜，第一圖為習知液晶面板背光裝置回授與保護 電路之電路方塊圖。請參考第一圖，輸入端子CN11各腳 分別接至輸入電壓、參考地端、致能訊號與調光訊號，其 中交換式開關控制電路1包含複數個功率電晶體（圖未示) 與一脈波寬度調整控制器2，脈波寬度調整控制器2輸出 端輸出複數個控制脈波，以驅動各式不同之開關拓樸讓功 率電晶體（圖未示）導通使得輸入電壓端可以從變壓器 T1〜T4的一次侧線圈轉換到二次侧線圈以傳送能量。二次 侧線圈的漏感與各串聯電容發生諧振現象而產生正弦波電 壓，其輸出到各冷陰極螢光燈管兩側使燈管發光供應背光 裝置之光源。其中變壓器T1二次側線圈的漏感與電容 Cll、C12串聯產生諳振，變壓器T2二次側線圈的漏感與 電容C21、C22串聯產生諧振，變壓器T3二次侧線圈的漏 感與電容C31、C32串聯產生諧振，變壓器T4二次側線圈 的漏感與電容C41、C42串聯產生諧振，輸出端子CN1〜CN4 兩端各自接一冷陰極螢光燈管分別接收諳振產生之交流正 弦波電源。電容C12、C22、C32、C42的作用是將各高壓 輸出分壓後經過二極體Dll、D21、D31、D41而取得電壓 最大值，其經電阻R3、R2分壓後輸入脈波寬度調整控制 器2的電壓回授輸入端。二極體D12、D22、D32、D42的 作用是將電容C12、C22、C32、C42的負向電壓箝位到二 極體順向壓降至大約負0.7V左右。二極體D15、D25、D35、 D45取得電容C12、C22、C32、C42的端電壓後，經過電 阻 R14 與 R15、R24 與 R25、R34 與 R35、R44 與 R45 分 M3 09184 別分麼與電容C13、C23、C33、C43濾波後，取得足夠的 正常運作時間的情形下讓電晶體Q11、q21、Q3l、卩竹導 通。當任一燈管發生短路時，則讓電晶體Qn、Q2卜QW、、 Q41採法導通到參考地端，電源電壓vcc立刻經電阻 、充電至電容C3。當電容C3充電達到電晶體Q1之作動電 •壓時，使電晶體Q1導通而將脈波寬度調整控制器2的電 流回授輸入端拉至低電位，使得脈波寬度調整控制器2停 止輸出，因而關閉背光裝置之所有輸出，電阻R33則為電 響容C3能量茂放之用。 另外，電阻Rll、R2卜R3卜R41分別接於冷陰極螢 光燈管與參考地端之間作為取得電流檢測訊號之用。二極 體D14、D24、D34、D44的作用是將電阻R11、R2卜咖、 R41的負向電壓箝位到二極體順向壓降至大約負〇·?ν左 右。二極體 D13、D23、D33、D43 取得電阻 R11、R21、 R3卜R41的電壓最大值，經電阻R4、R1分壓後輸入脈波 ❿見度”周整控制斋2的電流回授輸入端。二極體dig、D26、 036、046取得電阻1111、1121、1131、1141的端電壓，經 過電阻 R12 與 R13、R22 與 R23、R32 與 R33、R42 與 R43 分別分壓與電容C14、C24、C34、C44濾波後，取得足夠 正苇運作日守間的情形下讓電晶體Q12、Q22、Q32、Q42導 通，當任一燈管發生開路時，則讓電晶體q12、q22、q32、 Q42無法導通到參考地端，電源電壓vcc立刻經電阻r6 充電至電容C3，當電容C3充電達到電晶體Q1之作動電 壓犄，使電晶體Q1導通而將脈波寬度調整控制器2的電 7 M309184 流回授輸入端拉至低電位，使得脈波寬度調整控制哭 止輸出’因而_背域置之所有輸出。習知電路轉^ 為使用了許多的分散元件來達成回授與保護的控制電路·、、 增加印刷電路㈣局的_與面積，且提高整體換流電路 的成本’另外控制電晶體的作動電壓範圍過大，容易 調整不當而無法啟純軸作的可能性。 b "如何創作出一種液晶面板背光裝置之回授與保 '包路一簡化傳統以各別元件組成之回授與保護電路，減 /迅路7〇件佈局所佔的面積並降健體成本 所欲積極探討之處。 疋Μ作 【新型内容】 遂竭Ϊ鑑t上述習知之缺憾’發明人有感其未臻於完善， 婉驗曰悉心研究克服，憑其從事該項產業多年之累積 經驗，進而研發出—鍤、、产H 丁 尔4貝 路，以_用將電㈣/之曰曰面板背光裝置之回授與保護電 你片B 積體電路化設計，達到電路元件 佈局=的面積減少並降低整體成本的目的。 本創作之主要目的在接 授與保護電路，其藉由將電路;板背光裝置之回 元件佈局所佔的面積並降低整體=电路，達到減少電路 本創作々Η Μα 體成本的目的。 保護電路，包括.至餘晶面板背域置之回授與 祜·至少一變壓哭， 次極繞級…錢式開關控制;^有-初極繞組及一 制電路，其具有一脈波寬度調 M3 09184 整器，該交換式開關控制電路連接一輸入端子及該初級繞 組；一回授與保護控制單元’其具有至少一電流訊號輸入 端、至少一電壓訊號輸入端、一第一延遲控制端、一第二 延遲控制端及至少一異常狀態保護訊號端，該異常狀態保 護訊號端連接該脈波寬度調整器；至少一電流檢出元件， 其連接該電流訊號輸入端；至少一電壓檢出元件，其連接 該電壓訊號輸入端；以及至少一輸出端子，其連接該次極 繞組、一冷陰極螢光燈管、該電流檢出元件及該電壓檢出 元件；其中，當該冷陰極螢光燈管開路或短路時，該回授 與保護控制單元根據一第一參考電壓值及一第二參考電壓 值產生一異常狀保護訊號至該脈波寬度調整器，使該交 換式開關控制電路停止該液晶面板背光裝置之所有輸出。 藉此，利用將電路予以積體電路化設計，以簡化傳統 以各別元件組成之回授與保護電路，達到減少電路元件佈 局所佔的面積並降低整體成本的目的。 【實施方式】 為使貴審查委員充分瞭解本創作之目的、特徵及功 效，茲藉由下述具體之實施例，並配合所附之圖式， 創作做一詳細說明，說明如後： 、 第二圖為本創作之一具體實施例之液晶面板背光裝置 之回授與保護電路系統方塊圖，第三圖為示於第二图中 液晶面板背光裝置之回授與保護電路之詳細内部電路之 圖，而第六圖為示於第三圖中之液晶面板背光裝薏二 、回授 9 M309184 與保護電路之訊號波形圖。請同時參考第二圖、第三圖及 第六圖，此回授與保護電路系統包括：變壓器T1〜Τη，其 各具有一初極繞組及一次極繞組；一交換式開關控制電路 1，其具有一脈波寬度調整器2，交換式開關控制電路1連 接輸入端子CN11及初級繞組；一回授與保護控制單元 U1，其具有電流訊號輸入端S11〜Sin、電壓訊號輸入端 S21〜S2n、一第一延遲控制端VC1、一第二延遲控制端VC2 及異常狀態保護訊號端DT與連接至一反向器INV1所產生 的反向異常狀態保護訊號端DT’，異常狀態保護訊號端DT 連接脈波寬度調整器2 ;電流檢出元件，其分別由電阻 Rll-Rnl構成，並連接至電流訊號輸入端S11〜Sin;電壓 檢出元件，其分別由電容C11及C12、電容C21及C22... 電容Cnl及Cn2組成（亦可由多電阻組成或至少一電阻及一 電容組成），並連接至電壓訊號輸入端。其中，輸入該電流 訊號輸入端S21〜S2n之一電壓訊號為一交流電壓訊號或一 直流電壓訊號，而輸入該電壓訊號輸入端S21〜S2n之一電 壓訊號為一交流電壓訊號或一直流電壓訊號；以及輸出端 子CN1〜CNn，其連接次極繞組、冷陰極螢光燈管、電流檢 出元件及電壓檢出元件；電流訊號輸入端S11〜sln及電壓 訊號輸入端S21〜S2n各接一鉗位二極體將輸入訊號之負向 電壓鉗位到二極體順向壓降的準位。因此電壓訊號輸入端 S21〜S2n，電流訊號輸入端S11〜Sin之訊號將等於以下計 算式：M309184 VIII. New Description: [New Technology Field] This paper is about the feedback and protection circuit of a liquid crystal panel backlight device, especially the circuit design of the circuit to simplify the traditional composition of each component. The feedback and protection circuit reduces the surface area of the circuit component and reduces the overall cost. [Prior Art] The liquid crystal panel backlight device uses a high-frequency AC sine wave power supply to supply the energy of the cold cathode fluorescent lamp (CCFL), and therefore uses a DC-transfer muscle exchange circuit to achieve energy conversion. The conventional switching converter (DC/AC lnverter) uses a switching converter-specific pulse width regulator (PWM Controller) to control the entire converter circuit to provide all the cold cathode fluorescent lamps. Tube luminescence produces sufficient precursors. However, a pulse width adjuster has only one voltage feedback input terminal, _ current feedback input terminal and - an abnormal state protection control wheel human terminal, and the liquid crystal = device must be able to integrate each cold cathode fluorescent tube. The voltage and voltage are input, and then a single voltage feedback message is output. 1•刖Width adjustment controller's input end, while another === number to pulse wave) There is:: Two cathode glory lamp short circuit ( A "shape" of the human body touches the output of the abnormal state protection signal (not ',,, occupies, _ backlight, all output, to read and adjust the control to continue to damage the circuit components or cause the human body to touch the second : The road is not made up of different components. This is a fish eye. It is a customary way to protect money. The components 5 M309184 are numerous and complicated. The first picture shows the circuit of the feedback and protection circuit of the conventional LCD panel backlight device. Referring to the first figure, the input terminals CN11 are respectively connected to the input voltage, the reference ground, the enable signal and the dimming signal, wherein the switching switch control circuit 1 comprises a plurality of power transistors (not shown). With a pulse width adjustment Controller 2, the pulse width adjustment controller 2 outputs a plurality of control pulse waves to drive various different switch topologies so that the power transistor (not shown) is turned on so that the input voltage terminal can be from the transformers T1 to T4. The primary side coil is switched to the secondary side coil to transmit energy. The leakage inductance of the secondary side coil and the series capacitance resonate to generate a sine wave voltage, and the output is output to the sides of each cold cathode fluorescent lamp tube to make the lamp light supply. The light source of the backlight device, wherein the leakage inductance of the secondary side coil of the transformer T1 is in series with the capacitors C11 and C12, and the leakage inductance of the secondary side coil of the transformer T2 is resonated in series with the capacitors C21 and C22, and the secondary side coil of the transformer T3 The leakage inductance is in series with the capacitors C31 and C32 to generate resonance. The leakage inductance of the secondary side coil of the transformer T4 is resonated in series with the capacitors C41 and C42. The output terminals CN1 to CN4 are respectively connected to a cold cathode fluorescent tube to receive the vibration. The AC sine wave power supply. The functions of the capacitors C12, C22, C32, and C42 are to divide the respective high voltage outputs and then obtain the voltage maximum through the diodes D11, D21, D31, and D41. After R3 and R2 are divided, the voltage feedback input terminal of the pulse width adjustment controller 2 is input. The functions of the diodes D12, D22, D32, and D42 are to clamp the negative voltages of the capacitors C12, C22, C32, and C42 to The forward voltage of the diode drops to about 0.7V. The diodes D15, D25, D35, and D45 take the terminal voltages of capacitors C12, C22, C32, and C42, and then pass through resistors R14 and R15, R24 and R25, and R34. R35, R44 and R45 are divided into M3 09184. After filtering with capacitors C13, C23, C33 and C43, the transistors Q11, q21, Q3l and 卩 bamboo are turned on when sufficient normal operation time is obtained. When any of the lamps is short-circuited, the transistors Qn, Q2, QW, and Q41 are turned on to the reference ground, and the power supply voltage vcc is immediately charged and charged to the capacitor C3. When the capacitor C3 is charged to the operating voltage of the transistor Q1, the transistor Q1 is turned on to pull the current feedback input terminal of the pulse width adjusting controller 2 to a low level, so that the pulse width adjusting controller 2 stops outputting. Therefore, all the outputs of the backlight device are turned off, and the resistor R33 is used for the electric capacity C3 energy. In addition, the resistors R11 and R2, R3 and R41, are respectively connected between the cold cathode fluorescent lamp and the reference ground for obtaining a current detecting signal. The role of the diodes D14, D24, D34, and D44 is to clamp the negative voltages of the resistors R11, R2, and R41 to the forward voltage of the diode to about minus 〇·?ν. The diodes D13, D23, D33, D43 obtain the maximum voltage of the resistors R11, R21, R3 and R41, and input the pulse wave visibility after the voltage is divided by the resistors R4 and R1. The diodes dig, D26, 036, and 046 obtain the terminal voltages of the resistors 1111, 1121, 1131, and 1141, and are divided by the resistors R12 and R13, R22 and R23, R32 and R33, R42 and R43, respectively, and capacitors C14 and C24. After C34 and C44 are filtered, the transistors Q12, Q22, Q32, and Q42 are turned on when sufficient daytime operation is achieved. When any of the lamps is open, the transistors q12, q22, q32, and Q42 cannot be turned on. Conducted to the reference ground, the power supply voltage vcc is immediately charged to the capacitor C3 via the resistor r6. When the capacitor C3 is charged to the operating voltage of the transistor Q1, the transistor Q1 is turned on and the pulse width adjustment controller 2 is powered by the current 7 M309184 flow. The feedback input is pulled to a low potential, so that the pulse width adjustment control controls the output of the crying output, and thus all the outputs of the back domain. The conventional circuit turns into a control circuit that uses a plurality of discrete components to achieve feedback and protection. , and increase the number of printed circuits (four) Accumulate, and increase the cost of the overall converter circuit 'In addition to control the operating voltage range of the transistor is too large, easy to adjust improperly and can not open the axis of the possibility. b " How to create a liquid crystal panel backlight device feedback and protection 'Baoluyi simplifies the traditional feedback and protection circuit composed of different components, reducing the area occupied by the 7-piece layout and reducing the cost of the body. 疋Μ作【新内容】 遂Dedicated to the shortcomings of the above-mentioned knowledge, the inventor felt that he had not perfected it, and he did his best to overcome it. Based on his accumulated experience in the industry for many years, he developed and produced 丁, The road is designed to be used for the feedback and protection of the panel backlight device of the electric (4)/theft. The circuit design of the integrated circuit B is designed to achieve the purpose of reducing the area of the circuit component layout and reducing the overall cost. The main purpose of this creation In the receiving and protecting circuit, by reducing the area occupied by the circuit backplane component and reducing the overall = circuit, the purpose of reducing the cost of the circuit is reduced. , including. to the back of the crystal panel back to the feedback and 祜 · at least one pressure crying, the second pole winding ... money switch control; ^ there - primary winding and a system circuit, which has a pulse width modulation M3 09184, the switching switch control circuit is connected to an input terminal and the primary winding; a feedback and protection control unit has at least one current signal input terminal, at least one voltage signal input terminal, and a first delay control terminal a second delay control terminal and at least one abnormal state protection signal terminal, wherein the abnormal state protection signal terminal is connected to the pulse width adjuster; at least one current detecting component is connected to the current signal input terminal; and at least one voltage is detected. An element connected to the voltage signal input terminal; and at least one output terminal connected to the secondary pole winding, a cold cathode fluorescent lamp tube, the current detecting component and the voltage detecting component; wherein, when the cold cathode fluorescent device When the light tube is open or shorted, the feedback and protection control unit generates an abnormal protection signal according to a first reference voltage value and a second reference voltage value to adjust the pulse width So that the switching control circuit stops the switching liquid crystal panel backlight all the output devices. Therefore, the circuit is designed to be integrated into the circuit, so as to simplify the conventional feedback and protection circuit composed of individual components, thereby reducing the area occupied by the circuit component layout and reducing the overall cost. [Embodiment] In order to make the reviewer fully understand the purpose, characteristics and efficacy of this creation, the following specific examples, together with the attached drawings, are used to create a detailed explanation, as follows: 2 is a block diagram of a feedback and protection circuit system of a liquid crystal panel backlight device according to a specific embodiment of the present invention, and FIG. 3 is a detailed internal circuit of a feedback and protection circuit of the backlight device of the liquid crystal panel shown in FIG. FIG. 6 is a signal waveform diagram of the liquid crystal panel backlight assembly 2 and the feedback 9 M309184 and the protection circuit shown in the third figure. Please refer to the second diagram, the third diagram and the sixth diagram at the same time. The feedback and protection circuit system comprises: transformers T1~Τη, each having a primary winding and a primary winding; and a switching switch control circuit 1 The utility model has a pulse width adjuster 2, the switching switch control circuit 1 is connected with the input terminal CN11 and the primary winding; a feedback and protection control unit U1 has a current signal input terminal S11~Sin, a voltage signal input terminal S21~S2n, A first delay control terminal VC1, a second delay control terminal VC2, and an abnormal state protection signal terminal DT are connected to an inverted abnormal state protection signal terminal DT' generated by an inverter INV1, and the abnormal state protection signal terminal DT is connected. Pulse width adjuster 2; current detecting component, which is respectively composed of resistors R11-Rnl, and is connected to current signal input terminals S11~Sin; voltage detecting components, which are respectively composed of capacitors C11 and C12, capacitors C21 and C22. The capacitors Cnl and Cn2 (which may also be composed of multiple resistors or at least one resistor and one capacitor) are connected to the voltage signal input terminal. Wherein, one of the voltage signals input to the current signal input terminals S21 to S2n is an AC voltage signal or a DC voltage signal, and one of the voltage signals input to the voltage signal terminals S21 to S2n is an AC voltage signal or a DC voltage signal. And output terminals CN1~CNn connected to the secondary winding, the cold cathode fluorescent tube, the current detecting component and the voltage detecting component; the current signal input terminal S11~sln and the voltage signal input terminals S21~S2n each connected to a clamp The bit diode clamps the negative voltage of the input signal to the level of the diode's forward voltage drop. Therefore, the voltage signal input terminals S21 to S2n, the signal of the current signal input terminals S11 to Sin will be equal to the following calculation formula:
S21 〜S2n 之訊號二 VCn2 =2*Vo(n)*[Cnl/(Cnl+Cn2)]_VD M309184 S11 〜Sin 之訊號=Io(n)*Rnl 其中，Vo(l)〜Vo(n)為第一輸出電壓〜第n輸出電壓， 1〇(1)〜Ιο(η)為第一輸出電流〜第η輸出電流，VD為二極體 電壓。 ， 第一回授輸出FBI及第二回授輸出FB2係將電流訊號 • 輸入端S11〜Sin之訊號與電壓訊號輸入端S21〜S2n之訊號 整合後經過二極體取出最大值，第一回授輸出FBI及第二 回授輸出FB2將等於以下計算式：S21 ~ S2n signal two VCn2 = 2 * Vo (n) * [Cnl / (Cnl + Cn2)] _ VD M309184 S11 ~ Sin signal = Io (n) * Rnl where Vo (l) ~ Vo (n) is The first output voltage to the nth output voltage, 1〇(1)~Ιο(η) are the first output current to the nth output current, and VD is the diode voltage. The first feedback output FBI and the second feedback output FB2 integrate the current signal and the signal of the input terminal S11~Sin with the signal of the voltage signal input end S21~S2n, and then the maximum value is taken through the diode, the first feedback The output FBI and the second feedback output FB2 will be equal to the following formula:
_ FB1=[S11 〜Sin] max-VD_ FB1=[S11 ~Sin] max-VD
FB2=[S21 〜S2n] max-VD 當任一冷陰極螢光燈管發生開路（未點亮）時，多組單 一輸入的電流比較器C0MP11〜COMPln比較電壓訊號之 峰值與第一參考電壓值VERF1，當電壓訊號之峰值低於第 一參考電壓值VERF1時，多組單一輸入的電流比較器 C0MP11〜COMPln輸出一停止訊號，使第一延遲控制端 ⑩ VC1電壓逐漸上升。當第一延遲控制端VC1電壓高於第二 參考電壓值VERF2時，回授與保護控制單元經由異常 狀悲保濩吼號端DT輸出異常狀態保護訊號；當冷陰極螢 光燈管短路時，多組單一輸入的電壓比較器 C0MP21〜C0MP2n比較該電壓訊號之峰值與該第一參考電 壓值VERF1，當電壓訊號之峰值低於第一參考電壓值 VERF1時，電壓比較器c〇Mp21〜c〇Mp2n輸出一停止訊 號，使第二延遲控制端VC2電壓逐漸上升。當第二延遲控 制端VC2電壓高於第二參考電壓值VERF2時，回授與保 11 M309184 濩控制單元υι經由該異常狀態保護訊號端DT輸出該異常 狀態保護訊號。纟中，延遲控制第一延遲控制端VC1及第 二延遲控制端VC2的方式為—内設固定延遲控制方式或一 外部延遲控制方式。 第四圖為本創作之另一具體實施例之液晶面板背光裝 置之回授與保護電路系統方塊圖，其應用於LCDJTV等輸 出端子無返回線(RETURN)的情形，請參考第四圖，第四圖 無返回線與第二圖有返回線(RETURN)的差異在於第二圖 的電壓與氣之輸入訊號交流波形皆為同向，第四圖之電 壓與電流之輸入訊號交流波形則為反向，除電壓與電流之 輸入訊號父流波形反向外，動作方式無任何不同，本創作 如第二圖與第四圖可提供不同之應用選擇。 弟五圖為示於第三圖中之液晶面板背光裝置之回授與 保護電路之另一電路構成方塊圖，其與第三圖不同處係將 第三圖中之多組單一輸入的電流比較器C〇MPU〜C〇Mpln 及多組單一輸入的電壓比較器C0MP21〜C0MP：2n分別整 合為一多組輸入的電流比較器C0MP1及一多組輸入的電 壓比較器C0MP2，使電路更為精簡。 如上所述，本創作係利用將電路予以積體電路化設 計，以簡化傳統以各別元件組成之回授與保護電路，進而 達到減少電路元件佈局所佔的面積並降低整體成本的目 的；就產業上的可利用性而言，利用本創作所衍生的產品， 當可充分滿足目前市場的需求。 本創作在上文中已以較佳實施例揭露，然熟習本項技 12 M309184 術者應理解的是，該實施例僅用於描繪本創作，而不應解 讀為限制本創作之範圍。應注意的是，舉凡與該實施例等 效之變化與置換，均應設為涵蓋於本創作之範齊内。因此， 本創作之保護範圍當以下文之申請專利範圍所界定者為準 【圖式簡單說明】 第一圖為習知液晶面板背光裝置之回授與保護電路之 電路方塊圖。 第二圖為本創作之一具體實施例之液晶面板背光裝置 之回授與保護電路系統方塊圖。 第三圖為示於第二圖中之液晶面板背光裝置之回授與 保護電路之詳細内部電路方塊圖。 第四圖為本創作之另一具體實施例之液晶面板背光裝 置之回授與保護電路系統方塊圖。 第五圖為示於第三圖中之液晶面板背光裝置之回授與 保護電路之另一電路構成方塊圖。 第六圖為示於第三圖中之液晶面板背光裝置之回授與 保護電路之訊號波形圖。 【主要元件符號說明】FB2=[S21 ～S2n] max-VD When any cold cathode fluorescent lamp tube is open (not lit), multiple sets of single-input current comparators COMMP11~COMPln compare the peak value of the voltage signal with the first reference voltage value. VERF1, when the peak value of the voltage signal is lower than the first reference voltage value VERF1, the plurality of sets of single-input current comparators C0MP11~COMPln output a stop signal, so that the voltage of the first delay control terminal 10 VC1 gradually rises. When the voltage of the first delay control terminal VC1 is higher than the second reference voltage value VERF2, the feedback and protection control unit outputs an abnormal state protection signal via the abnormality 濩吼 濩吼 terminal DT; when the cold cathode fluorescent tube is short-circuited, The plurality of single-input voltage comparators C0MP21 to C0MP2n compare the peak of the voltage signal with the first reference voltage value VERF1. When the peak value of the voltage signal is lower than the first reference voltage value VERF1, the voltage comparator c〇Mp21~c〇 Mp2n outputs a stop signal, so that the voltage of the second delay control terminal VC2 gradually rises. When the voltage of the second delay control terminal VC2 is higher than the second reference voltage value VERF2, the feedback control unit outputs the abnormal state protection signal via the abnormal state protection signal terminal DT. In the meantime, the manner of delay controlling the first delay control terminal VC1 and the second delay control terminal VC2 is to set a fixed delay control mode or an external delay control mode. The fourth figure is a block diagram of the feedback and protection circuit system of the liquid crystal panel backlight device according to another specific embodiment of the present invention, which is applied to the case where the output terminal of the LCD JTV has no return line (RETURN), please refer to the fourth figure, The difference between the return line of the four graphs and the return line (RETURN) of the second graph is that the voltage of the second graph is the same as the waveform of the input signal of the gas, and the waveform of the input signal of the voltage and current of the fourth graph is reversed. In addition to the voltage and current input signal parent flow waveform is reversed, there is no difference in the action mode. This creation, as shown in the second and fourth figures, can provide different application options. The fifth figure is a block diagram of another circuit configuration of the feedback and protection circuit of the liquid crystal panel backlight device shown in the third figure, which is different from the third figure in comparing the currents of multiple sets of single inputs in the third figure. The C〇MPU~C〇Mpln and the multiple sets of single-input voltage comparators C0MP21~C0MP:2n are respectively integrated into a multi-group input current comparator C0MP1 and a multi-group input voltage comparator COMP2, which makes the circuit more streamlined. . As described above, the present invention utilizes a circuitized circuit design to simplify the conventional feedback and protection circuit composed of individual components, thereby achieving the purpose of reducing the area occupied by the circuit component layout and reducing the overall cost; In terms of industrial availability, the products derived from this creation can fully meet the needs of the current market. The present invention has been disclosed in the above preferred embodiments, and it is to be understood that the present invention is only intended to depict the present invention and should not be construed as limiting the scope of the present invention. It should be noted that variations and permutations that are equivalent to the embodiment should be considered to be within the scope of this creation. Therefore, the scope of protection of this creation is subject to the definition of the following patent application. [Simplified illustration] The first figure is a circuit block diagram of the feedback and protection circuit of the conventional LCD panel backlight device. The second figure is a block diagram of the feedback and protection circuit system of the liquid crystal panel backlight device of one embodiment of the present invention. The third figure is a detailed internal circuit block diagram of the feedback and protection circuit of the liquid crystal panel backlight device shown in the second figure. The fourth figure is a block diagram of the feedback and protection circuit system of the liquid crystal panel backlight device of another specific embodiment of the present invention. Fig. 5 is a block diagram showing another circuit configuration of the feedback and protection circuit of the liquid crystal panel backlight device shown in Fig. 3. The sixth figure is a signal waveform diagram of the feedback and protection circuit of the liquid crystal panel backlight device shown in the third figure. [Main component symbol description]
Rn電阻 Cn電容 Dn二極體 13 M309184 DBn二極體 Qn電晶體 CN11輸入端子 CN1〜CNn輸出端子 F1保險絲 T1〜Τη變壓器Rn resistor Cn capacitor Dn diode 13 M309184 DBn diode Qn transistor CN11 input terminal CN1~CNn output terminal F1 fuse T1~Τη transformer
Vol〜Vo(n)第一輸出電壓〜第η輸出電壓 1〇(1)〜Ιο(η)第一輸出電流〜第η輸出電流 C0MP1、C0MP11〜COMPln電流比較器 C0MP2、C0MP21〜C0MP2n電壓比較器 COMPn比較器 VCC電源電壓 VD二極體電壓 U1回授與保護控制單元 S11〜Sin電流訊號輸入端 S21〜S2n電壓訊號輸入端 VC1第一延遲控制端 VC2第二延遲控制端 FBI第一回授輸出 FB2第二回授輸出 DT異常狀態保護訊號端 DT’反向異常狀態保護訊號端 INV1反向器 1交換式開關控制電路 14 M309184 2脈波寬度調整控制器 GND參考地端 VERF1第一參考電壓值 VERF2第二參考電壓值Vol~Vo(n) first output voltage~nth output voltage 1〇(1)~Ιο(η) first output current~nth output current C0MP1, C0MP11~COMPln current comparator C0MP2, C0MP21~C0MP2n voltage comparator COMPn comparator VCC power supply voltage VD diode voltage U1 feedback and protection control unit S11~Sin current signal input terminal S21~S2n voltage signal input terminal VC1 first delay control terminal VC2 second delay control terminal FBI first feedback output FB2 second feedback output DT abnormal state protection signal terminal DT' reverse abnormal state protection signal terminal INV1 inverter 1 switching switch control circuit 14 M309184 2 pulse width adjustment controller GND reference ground VERF1 first reference voltage value VERF2 second reference voltage value
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