M275668 八、新型說明： 【新型所屬之技術領域】 本新型是有關於一種點燈驅動電路，特別是指一 種用以驅動並點亮冷陰極管（CCFL)之換流器（inverter) 點燈驅動電路。 【先前技術】 一般LCD面板是以冷陰極管（c〇][d Fluorescent Lamp，CCFL)做為其背光源。而這類的冷 陰極官通常是由一換流器（Inverter)點燈驅動電路來驅 動’以產生足夠高的電壓來點亮冷陰極管。 如圖1所示，是台灣公告第52 1947號專利所揭露 之一種換流器點燈驅動電路]，其接受一電源供應電路 20控制，以驅動與其連接之冷陰極管（CCFL)。電路] 主要包括由兩電晶體Q1、q2及一電容c]組成之一推 挽式驅動電路11及一變壓器12。變壓器12的初級側（ 線圈）包括一激磁線圈Lm及一驅動控制線圈Ld，且激 磁線圈Lm的中間點與電源供應電路2連接，變壓器 1 2的次級側（線圈）一端分別經由一高壓電容匚2、c 3與 兩個冷陰極管（CCFL)21、22並聯。電晶體Q1及q2的 汲極分別與激磁線圈Lm的兩端連接，其基極分別與驅 動控制線圈Ld的兩端及電源供應電路2連接，其源極 接地，且電容C1串聯在電晶體Q1及q2的汲極之間 〇 藉由上述電路結構，在電路運作過程中，驅動控 5 M275668 _ 制線圈Ld會輪流驅動電晶體Q】及Q2導通，使輪流產 ， 生電流對激磁線圈Lm激磁，使與次級側線圈耦合以產 生足夠的電壓點亮冷陰極管（CCFL)21、22。 但由於每一支冷陰極管（CCFL)的阻抗不盡相同， 所以在電路1中，以並聯方式連接的冷陰極管21、22 會因為阻抗不同導致流過的電流不相同，而造成亮度 不平均，因此，如圖1所示，以往的做法是在電路i 之兩冷fe極官（CCFL)21、22的另一端與變壓器j之次 級側線圈的另一端之間，設置一平衡變壓器㈣a· Chock)13來平衡流過兩個冷陰極管（ccfl)2i、的電 流0 此外，因為電路1最多只能驅動兩支燈管，當需 要使用的燈管數大於2,例如4支燈管時，則必需使用 兩個相同的…來駆動4支燈管，使得電路更形複 雜且佔用電路板空間。 再蒼見圖2所示，是美國第454954〇5號專利揭露 之-種冷陰極管（CCFL)驅動電路6,與上述習知電路】 相較’其初級側電路61只能驅動單—個變壓器，以及 决疋工作頻率’其次級側電路62增加—個電感Μ及 高壓，容5與冷陰極管（〔叫並聯，而且只能驅動一 支燈管65,因此，當需要使用的燈管數大於2時，則 必需使用多組相同的電@ 6來分別驅動多支燈管，使 得電路更形複雜並且佔用電路板空間。 【新型内容】 6 M275668 因此’本新型之目的，在於提供—種可簡化電路 =，縮小電路體積，並平衡輸出電流，使發光效 Ί思疋之換流器（Inverter)點燈驅動電路。M275668 8. Description of the new model: [Technical field to which the new model belongs] The new model relates to a lighting driving circuit, particularly an inverter lighting driver for driving and lighting a cold cathode tube (CCFL). Circuit. [Previous Technology] Generally, LCD panels use cold cathode tubes (c0) [d Fluorescent Lamp (CCFL)] as their backlight source. And this kind of cold cathode is usually driven by an inverter lighting driving circuit 'to generate a sufficiently high voltage to light up the cold cathode tube. As shown in FIG. 1, it is a converter lighting driving circuit disclosed in Taiwan Publication No. 52 1947], which is controlled by a power supply circuit 20 to drive a cold cathode tube (CCFL) connected thereto. The circuit] mainly includes a push-pull driving circuit 11 and a transformer 12 composed of two transistors Q1, q2 and a capacitor c]. The primary side (coil) of the transformer 12 includes an excitation coil Lm and a drive control coil Ld. The middle point of the excitation coil Lm is connected to the power supply circuit 2. One end of the secondary side (coil) of the transformer 12 is connected to a high-voltage capacitor.匚 2 and c 3 are connected in parallel with two cold cathode tubes (CCFL) 21 and 22. The drains of the transistors Q1 and q2 are connected to the two ends of the excitation coil Lm, and the bases thereof are connected to the two ends of the drive control coil Ld and the power supply circuit 2, respectively. The sources are grounded, and the capacitor C1 is connected in series to the transistor Q1. With the drain of q2 through the above circuit structure, during the circuit operation, the driving control 5 M275668 _ control coil Ld will drive the transistor Q in turn] and Q2 are turned on, so that turns are produced, and the current is excited to the exciting coil Lm. , Coupling with the secondary-side coil to generate enough voltage to light up the cold cathode tubes (CCFL) 21,22. However, since the impedance of each CCFL is not the same, in Circuit 1, the cold cathode tubes 21 and 22 connected in parallel will have different currents flowing due to different impedances, resulting in different brightness. On average, therefore, as shown in Fig. 1, a conventional method is to install a balancing transformer between the other ends of the two CCFLs 21 and 22 of the circuit i and the other end of the secondary-side coil of the transformer j. ㈣a · Chock) 13 to balance the current flowing through two cold cathode tubes (ccfl) 2i and 0. In addition, because circuit 1 can only drive two lamps at most, when the number of lamps needed is greater than 2, for example 4 lamps When the tube is used, it is necessary to use two identical ... to move 4 lamps, making the circuit more complex and occupying board space. As shown in Figure 2, it is disclosed in US Patent No. 45495405-a kind of cold cathode tube (CCFL) drive circuit 6, compared with the above-mentioned conventional circuit] its primary-side circuit 61 can only drive a single Transformer, and determine the operating frequency of its secondary side circuit 62-an inductance M and high voltage, capacity 5 and cold cathode tube (called parallel, and can only drive one lamp 65, so when the lamp is needed When the number is greater than 2, you must use multiple sets of the same electricity @ 6 to drive multiple lamps separately, making the circuit more complex and occupying space on the circuit board. [New Content] 6 M275668 Therefore 'The purpose of this new model is to provide— This kind of circuit can simplify the circuit, reduce the volume of the circuit, and balance the output current, so that the inverter can turn on the lighting drive circuit.
έ於是’本新型之換流器（Inverte〇點燈驅動電路， =接X —電源供應電路控制’用以點亮與其連接之冷 =柽官（CCFL) ’該換流器（Inverter)點燈驅動電路包括 -第-變壓器、一第二變壓器及一推挽式(ρ_ Μ)驅 力電路。該第一變塵器的初級側線圈與該電源供應電 路連接，其次級側線圏兩端可供分別串接一冷陰極管 (CCFL)。該第二㈣器的初級側線圈與該第—變麼哭 之初級側線圈串接並與該電源供應電路連接，其次級 側線圈兩端可供分別串接—冷陰極f(ccFL)。該推挽 j (Push Pull)驅動電路分別與該第一變壓器及第二變壓 器之初級側線圈以及哕兩、店W ^ “ U 乂及4兒源供應電路連接，以接受該 電：供應電路供電，並輪流對該第一變塵器與第二變 I -之？刀級側線圈激磁’使與對應之次級側線圈產生 輕合’而點亮與各該次級側線圈串接之冷陰極管 (CCFL)。 【實施方式】 其他技術内容、特點與功效 一較佳實施例的詳細說明中 器（Inverter)點燈驅動 ，本實施例之換流器 有關本新型之前述及 在以下配合參考圖式之 將可清楚的呈現。 〆小，疋本】 電路的一較佳實施例之電與 7 M275668 (InVener)點燈驅動電路3是受一電源供應電路40控制， 用以點亮與其連接之冷陰極f (CCFL)(在本實施例中是以 四支k g 5 1〜54為例）。其中電源供應電路*的詳細電 路如圖4所不’但因為電源供應電路4〇本身並非本案發 明重點’且並不限於圖4所示範之電路態樣，故在本實 施例說明過程中，仍以圖3之電路方塊取代其詳細電路 來進行說明。Then "The inverter of this new type (Inverte lighting driving circuit, = connected to X — power supply circuit control 'to light the cold connected to it = CCFL)' The inverter (Inverter) lighting The driving circuit includes a first transformer, a second transformer, and a push-pull (ρ_M) driving circuit. The primary-side coil of the first dust collector is connected to the power supply circuit, and both ends of its secondary-side line 可供 are available A cold cathode tube (CCFL) is connected in series. The primary-side coil of the second device is connected in series with the primary-side coil of the first transformer and connected to the power supply circuit. Series connection—cold cathode f (ccFL). The push-pull j (Push Pull) drive circuit is connected to the primary-side coils of the first transformer and the second transformer, as well as the two, store W ^ "U 乂, and 4 child source supply circuits. Connected to receive the electricity: the supply circuit supplies power, and turns the first dust collector and the second transformer I-in turn? The knife-side coil is excited to 'make light-on with the corresponding secondary-side coil' to light and A cold cathode tube (CCFL) connected in series with each of the secondary side coils. Other technical contents, features and effects A detailed description of a preferred embodiment of the inverter (Inverter) lighting drive, the inverter of this embodiment related to the new model and will be clearly presented with reference to the following drawings. 〆 小 ， 本本】 A preferred embodiment of the circuit and the 7 M275668 (InVener) lighting drive circuit 3 is controlled by a power supply circuit 40 to light up the cold cathode f (CCFL) connected to it (in In this embodiment, four kg 5 1 to 54 are taken as an example. The detailed circuit of the power supply circuit * is shown in FIG. 4 'but the power supply circuit 40 itself is not the focus of the present invention' and is not limited to FIG. 4 The exemplified circuit state is described in the description of this embodiment with the circuit block of FIG. 3 instead of the detailed circuit.
換流器（Inverter)點燈驅動電路3包括—第一變壓器 η、一第二變壓器32及一推挽式驅動電路33。 °° 第-變壓器31及第二變壓器32分別具有一初級側 線圈U1、L21及一次級側線圈L】2'L22，其中初級側 線圈L 11 & L2 I分別包含_激磁線圈Lm】、Lm2及—駆 動控制線圈Ld!及Ld2(其係另外繞設在第一及第二變塵 器31、32的初級側上，以與激磁線圈Lml、Lm2耦合 而感應在激磁線圈Lml、Lm2ji的電愿）。激磁線圈The inverter lighting driving circuit 3 includes a first transformer η, a second transformer 32, and a push-pull driving circuit 33. °° The first-transformer 31 and the second transformer 32 respectively have a primary-side coil U1, L21 and a primary-side coil L] 2′L22, wherein the primary-side coil L 11 & L2 I includes _excitation coil Lm], Lm2 And—the control coils Ld! And Ld2 (which are additionally wound on the primary sides of the first and second dust filters 31, 32, and are coupled to the excitation coils Lml, Lm2 to induce the electric current in the excitation coils Lml, Lm2ji willing). Exciting coil
Lm2以一端相串接並與電源供應電路40連接，驅動控 制線圈Ldl及Ld2以一端相串接’其另一端分別與電源 :應電路40連接。而次級側線圈U2 & L22的兩端則 刀別串接冷極官5 1〜5 4。此外，在次級側線圈L j 2 L22的兩端之間更並聯有一高壓電容（在本實施例中是 :兩串聯之高壓電纟C】、C2或雜散電容C4為例)，其 分別用以與次級側線圈L12、L22(具有雜散電容）及燈管 51 52和53、54(具有浮游電容）相配合以產生[匸諧振 ，並以其諧振頻率做為冷陰極管（CCFL)的工作頻率。 8 M275668 推挽式（Push Pull)驅動電路 圈W及Lm2的另一端連接與激磁錄 線圈Ldl及Ld2的另一端連 土刀別與艇動控制 ^ *連接，亚透過線電阻R1〜R4盘 ^應電路4G連接，其源極接地4電容C3串接在 —电晶體Q1及Q2的汲極之間。 線圈UU及Ld2會產生一起奸^:匕與駆動控制 A 起始6自振頻率，並轉移到次級Lm2 is connected in series at one end and connected to the power supply circuit 40, and the drive control coils Ldl and Ld2 are connected in series at one end ', and the other ends thereof are respectively connected to the power supply circuit 40. The two ends of the secondary side coil U2 & L22 are connected in series with cold poles 5 1 ~ 54. In addition, a high-voltage capacitor is further connected in parallel between the two ends of the secondary-side coil L j 2 L22 (in this embodiment: two series-connected high-voltage capacitors C, C2, or stray capacitor C4 as examples), Used to cooperate with secondary side coils L12, L22 (with stray capacitance) and lamp tubes 51 52 and 53, 54 (with floating capacitance) to generate [匸 resonance, and use its resonance frequency as a cold cathode tube ( CCFL). 8 The other end of the M275668 Push Pull drive circuit coils W and Lm2 is connected to the other end of the excitation recording coils Ldl and Ld2, and the earth knife is connected to the boat movement control. ^ * Connected to the sub-line resistance R1 ~ R4 disk ^ Should be connected to the circuit 4G, and its source ground 4 capacitor C3 is connected in series between the drains of the transistors Q1 and Q2. The coil UU and Ld2 will generate a gang ^: dagger and movement control A. Initial 6 natural frequency and transfer to the secondary
側由次級側線圈L12及L22與高塵電容或印刷 電路板在變壓器下方佈線之間所產生的雜散電容c似 冷陰極管（CCFL)5】、52和53、54(具有浮游電容）相配合 =產生LC言皆振，因此，起始言皆振頻率應等於該冷陰極 管5 1〜54之工作頻率。 藉此，在電路運作過程中，第一及第二變壓器qi、 Q2的驅動控制線圈Ldl及Ld2可藉由感應激磁線圈 Lml及Lm2的感應電壓，以及透過線電阻R1〜R4與電 源供應電路40相連之補償電壓來驅動電晶體Q]、Q2輪 流導通，當電晶體Q1導通（〇N)時，電流流過激磁線圈 L m 1而對激磁線圈l m 1激磁，使與其次級側線圈l 12互 相耦合，以在次級側線圈L1 2上產生一足夠高的電壓點 亮冷陰極管5 1及52，此時驅動控制線圈Ld 1由激磁線 圈Lml處感應之電壓促使電晶體q!關閉（〇fF)，電晶體 Q2導通（ON)，使電流流過激磁線圈Lin2而對激磁線圈 Lm2激磁，使其次級側線圈L22產生一足夠高的電壓點 亮冷陰極管53及54，同時，驅動控制線圈Ld2由激磁 9 M275668 、.泉圈Lm2處感應之電壓促使電晶體q2關閉，使電 晶體Q2再度導通（0N)，而反覆上述動作。因此，由於 驅動控制線圈Ldl、Ld2會輪流驅動電晶體Q1及Q2， 使兩兩冷陰極管51、52及53、54輪流被點亮。 由上述說明可知，本實施例之換流器（Inverter)點燈 驅動電路3與習知電路]及電路6相較，除了可以簡化 電路’減少佔用電路板上的佈局面冑，並且最多可以一 次同時驅動（點亮）四支冷陰極管51〜54外，而且由於冷 陰極官51〜54是以串聯方式與第—及第二變壓器3ι、32 之次級側線圈L12、L22連接，因此即使冷陰極管5卜54 的阻抗有所不同，流過冷陰極管51、52及53、W的電 流仍會是相同的，不會有電流不平均的情況，使冷陰極 官51、52及53、54產生的亮度可以很均勾。因此，本 實施例之電路3 了可以改善習知電路i流過燈管電流 不平均的問題外，而且不需額外使用習知電路]的平衡 變壓器（Balance Chock)來平衡流經燈管的電流。 當然，本實施例雖然是以點亮四支燈管為較佳實施 例子，但也可以藉由簡單地改變電路接線方式，點亮多 支、兩支或一支燈管。 此外’如圖3所示，冷陰極管5丨、52及53、之 一端與第一及第二變壓器31、32之次級側線圈u2、 L22串接，其另一端可再經由_回授電路 L〇〇P)41連接至電源供應電路4〇 ’其中回授電路 (Feedback L〇〇P)41的詳細電路可參照圖4所示（圖:之 10 M275668 回才又黾路（Feedback Loop)4 1係為一示範性電路，並不以 此為限），其用以收集流經各冷陰極管5丨〜54的電流並回 授（Feedback Loop)給電源供應電路4〇，使電源供應電路 4〇可根據回授（Feedback Loop)電流產生穩定的電源供應 給電路3。 另外，如圖3所示，本實施例更可在第一及第二變 壓器31、32之次級側高壓電容ci、C2之間，分別設置 一偵測點PI、P2偵測高壓電容ei、c2上之電壓變化（ 當=陰極管全部接上時，電容具有一較低電麼準位，當 燈管未接上或被拔除時，與燈管連接之電容會產生一高 電壓準位），並提供給電源供應電路4〇，藉此，當第一 及第二變壓器3]、32之次級側線圈U2、L22的任一端 未接冷陰極管（或冷陰極f在工作過程中被從次級側線圈 LU、L22的任一端拔除）時，電源供應電路4〇可透過偵 I’占PI、P2傳回之電容電麼變化得知上述情況，而立 即，止供應電源給換流器（Inverter)點燈驅動電路3，以 保3不致因冷陰極管未全部接上或突然被祓除時 承受過高之電壓而燒燬。 么淮乂上所述者，僅為本新型之較佳實施例而已，當 不施：此限定本新型實施之範圍，即大凡依本新型申請 專利範圍及新型說明内容所作之簡單的等效變化與修： ，皆仍屬本新型專利涵蓋之範圍内。 【圖式簡單說明】 圖疋白知一種換流器（invener)點燈，驅動電路之 11 M275668 電路圖； 圖2是習知一種冷陰極管（CCFL)點燈驅動電路之 電路圖， 圖3是本新型換流器（Inverter)點燈驅動電路的一 較佳實施例之電路圖；及 圖 4是本實施例之電源供應電路及回授電路 (Feedback Loop)的一示範性詳細電路圖。 12 M275668 【主要元件符號說明】 3 驅動電路 3 2 第二變壓器 5 1〜54冷陰極管 1 ' L21初級側線圈 Lml、Lm2激磁線圈 Cl、C2高壓電容 Q1、Q2電晶體 C4雜散電容 31第一變壓关 40電源供應電路 41回授電路 L1 2、L22次級側線圈 Ldl、Ld2驅動控制線圈 C3電容 PI、P2偵測點 Rl、R2、R3、R4 線電阻The stray capacitance between the secondary side coils L12 and L22 and the high-dust capacitor or the printed circuit board under the transformer is similar to the cold cathode tube (CCFL) 5], 52 and 53, 54 (with floating capacitance) Coordination = Generate LC all-oscillation, so the initial all-oscillation frequency should be equal to the operating frequency of the cold cathode tube 5 1 ~ 54. Thus, during the operation of the circuit, the drive control coils Ldl and Ld2 of the first and second transformers qi and Q2 can be induced by the induced voltages of the excitation coils Lml and Lm2, and through the line resistances R1 to R4 and the power supply circuit 40 The connected compensation voltage drives the transistor Q] and Q2 to turn on in turn. When transistor Q1 is turned on (ON), current flows through the excitation coil L m 1 and excites the excitation coil lm 1 to make it the secondary side coil l 12 They are coupled to each other to generate a sufficiently high voltage on the secondary-side coil L1 2 to illuminate the cold cathode tubes 5 1 and 52. At this time, the driving control coil Ld 1 is driven by the voltage induced at the excitation coil Lml to cause the transistor q! To turn off ( 〇fF), the transistor Q2 is turned on, and the current flows through the exciting coil Lin2 to excite the exciting coil Lm2, so that the secondary coil L22 generates a sufficiently high voltage to light up the cold cathode tubes 53 and 54. The voltage induced in the control coil Ld2 by the excitation 9 M275668 and the spring coil Lm2 causes the transistor Q2 to turn off, so that the transistor Q2 is turned on again (0N), and the above action is repeated. Therefore, the driving control coils Ldl and Ld2 drive the transistors Q1 and Q2 in turn, so that the pair of cold cathode tubes 51, 52, 53, and 54 are turned on in turn. As can be seen from the above description, the inverter (inverter) lighting driving circuit 3 of this embodiment is compared with the conventional circuit] and circuit 6, except that the circuit can be simplified, and the layout area on the circuit board is reduced, and it can be used at most once. Simultaneously drive (light up) four cold cathode tubes 51 ~ 54 at the same time, and since the cold cathode electrodes 51 ~ 54 are connected in series to the secondary side coils L12 and L22 of the first and second transformers 3 and 32, even if The impedances of the cold cathode tubes 5 and 54 are different, and the currents flowing through the cold cathode tubes 51, 52, and 53 will still be the same, and there will be no uneven current, which makes the cold cathode tubes 51, 52, and 53 The brightness produced by 54 can be very even. Therefore, the circuit 3 of this embodiment can improve the problem of the uneven current flowing through the lamp in the conventional circuit i, and does not require the use of a conventional circuit] balance transformer to balance the current flowing in the lamp. . Of course, in this embodiment, although four lamps are preferably used as the implementation examples, it is also possible to light multiple, two, or one lamp by simply changing the circuit wiring mode. In addition, as shown in FIG. 3, one end of the cold cathode tube 5 丨, 52, and 53 is connected in series with the secondary-side coils u2 and L22 of the first and second transformers 31 and 32, and the other end thereof can be passed through _ feedback The circuit L〇〇P) 41 is connected to the power supply circuit 40 ′. The detailed circuit of the feedback circuit (Feedback L〇〇P) 41 can be shown in Figure 4 (Figure: 10 M275668 feedback loop again (Feedback Loop ) 41 is an exemplary circuit, and is not limited to this), it is used to collect the current flowing through each cold cathode tube 5 丨 ~ 54 and feedback (Feedback Loop) to the power supply circuit 40, so that the power supply The supply circuit 40 can generate a stable power supply to the circuit 3 according to a feedback loop current. In addition, as shown in FIG. 3, in this embodiment, a detection point PI, P2 can be set between the secondary-side high-voltage capacitors ci and C2 of the first and second transformers 31 and 32 respectively to detect the high-voltage capacitors ei, The voltage change on c2 (when = all cathode tubes are connected, the capacitor has a lower level, when the tube is not connected or unplugged, the capacitor connected to the tube will generate a high voltage level) And supply it to the power supply circuit 40, whereby when either end of the secondary side coils U2, L22 of the first and second transformers 3], 32 is not connected to a cold cathode tube (or cold cathode f is When disconnected from the secondary side coils LU and L22), the power supply circuit 40 can learn the above situation by detecting the changes in the capacitance of the capacitors returned by PI and P2, and immediately stop supplying power to the commutation. Inverter lighting drive circuit 3, to ensure that 3 will not be burnt because the cold cathode tube is not fully connected or is suddenly overpowered when subjected to excessive voltage. What is mentioned above is only the preferred embodiment of the new model. It should not be applied: this limits the scope of the implementation of the new model, that is, the simple equivalent changes made according to the scope of the patent application and the description of the new model. And repair:, are still within the scope of this new patent. [Brief description of the figure] Figure Ⅱ shows a circuit diagram of an inverter lighting and driving circuit of M275668. Figure 2 is a circuit diagram of a conventional driving circuit of a cold cathode tube (CCFL) lighting. A circuit diagram of a preferred embodiment of a novel inverter lighting driving circuit; and FIG. 4 is an exemplary detailed circuit diagram of a power supply circuit and a feedback loop of this embodiment. 12 M275668 [Description of main component symbols] 3 Drive circuit 3 2 Second transformer 5 1 ~ 54 Cold cathode tube 1 'L21 Primary side coil Lml, Lm2 Excitation coil Cl, C2 High-voltage capacitor Q1, Q2 transistor C4 Stray capacitor 31st A voltage transformer 40 power supply circuit 41 feedback circuit L1 2, L22 secondary-side coils Ldl, Ld2 drive control coil C3 capacitor PI, P2 detection point R1, R2, R3, R4 line resistance
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