200930154 九、發明說明： 【發明所屬之技術領域】 本發明係有關於一種LED背光模組的驅動電路，特別 有關於一種LED之驅動裝置。 【先前技術】 由於LED具有響應速度快、節能、安全、壽命長與體 積小等優點，俾使許多廠商開始研製LED背光源，取;^冷200930154 IX. Description of the Invention: [Technical Field] The present invention relates to a driving circuit for an LED backlight module, and more particularly to an LED driving device. [Prior Art] Because LEDs have the advantages of fast response, energy saving, safety, long life and small volume, many manufacturers have begun to develop LED backlights.
陰極勞光燈（Cold Cathode Fluorescent Lamp，CCFL)。 隨著液晶顯示器朝向大尺寸發展，其背光模組需要數 十甚至數百顆之向冗度LED提供足夠的背光源，因此，背 光模組對於散熱之要求將更加嚴苛，進而配合適當的控制 方式來完成LED陣列驅動電流之均流效果。 一般欲完成LED陣列調光，會將LED陣列的驅動電流 維持在額定值，進而藉由一 pM (Pulse WidthCold Cathode Fluorescent Lamp (CCFL). As liquid crystal displays are heading toward large size, their backlight modules require tens or even hundreds of backlights to provide sufficient backlighting. Therefore, the backlight module will have more stringent requirements for heat dissipation, and thus with appropriate control. The way to achieve the current sharing effect of the LED array drive current. Generally, to complete the LED array dimming, the driving current of the LED array is maintained at the rated value, and then by a pM (Pulse Width)
Modulation ; PWM)信號，控制LED陣列驅動電流之點亮與 媳滅比例調節該亮度。請參閱第一圖，係為習知均流及酬 調光電路。背光LED陣列n係為複數LED陣列，包括複數 列11卜—’每—LED串列11卜lln分別連接複 # ’並由電源供應單元10經由直流電力線13供應 ⑶ρ串歹1所而之直流電壓。其次，背光LED陣列11中每一 〜lln係分別連接驅動電路12卜12n完成led '二電流平衡之目的。為方便說明，接下來以其中一 條支路加Μ述相__#。 如第 應單元10 "'圖所示其—支路，LED串列111係接收電源供 所提供之直流電壓，並透過驅動電路121做均流 6 200930154 及調光。驅動電路121中係包括運算放大器〇ρι、Modulation; PWM) signal that controls the LED array drive current to illuminate and annihilate the brightness. Please refer to the first figure for the conventional current sharing and compensation optical circuits. The backlight LED array n is a plurality of LED arrays, and includes a plurality of columns 11-'each-LED series 11 lln respectively connected to the complex #' and the DC voltage supplied by the power supply unit 10 via the DC power line 13 (3) ρ series 歹1 . Next, each of the backlight LED arrays 11 is connected to the driving circuit 12 and 12n to complete the LED 'two current balancing. For the convenience of explanation, the next step is to add the __#. As shown in the figure 10 "', the LED string 111 receives the DC voltage supplied by the power supply, and performs current sharing through the drive circuit 121 6 200930154 and dimming. The driving circuit 121 includes an operational amplifier 〇ρι,
晶體Q1、第二電晶體Q2、電阻R1。第一電晶體則之極 端（Drain)係連接至LED串列1U，第一電晶體如之 極端係連接至運算放大器0Π之輸出端，電晶體之源極; (Source)係連接至電阻R1之一端；而電阻幻之另一山 係接地。運算放大器0P1之非反相輸入端接收—來考 hf’反相輸人端連接至第-電晶體Q1之源極端與^ R1間。第二電晶體Q2之汲極端係連接至運算放大器〇ρι 之輸出與第一電晶體Q1之閘極端之間，第二電晶體^呢之 閘極端係接收一 PWM調光控制信號，而第二電晶體 極端係接地。 "、 ,承上述，運算放大器、第一電晶體Q1及電阻R1 係構成^線性調節器（Linear 卯lat〇r)，線性調節器藉 由運算放大器0P1比較參考電壓Vref與電阻耵之壓降， 用以限制第一電晶體Q1所通過之電流丨丨。其次，當第二 電，體Q2導通時（Turnon)，運算放大器0N之輸出端， 因第二電晶體Q2接地使其輸出電壓為零，俾使第一電晶體 =呈現截止（Turn off)狀態，因此，LED串列ill亦無電 流通過。當第二電晶體Q2為截止狀態時，運算放大器”〇ρι 之輸出端將提供一電位，以使第一電晶體Q1導通，並維持 LED串列111所需之驅動電流。 ^然而，習知的電路架構上，每條驅動電路121〜12η必 /頁使用2顆電晶體Ql、Q2，隨著LED串列數越多，亦需增 加電晶體，故大幅提高電路成本。再者，隨LED串列111 刼1時間之增加，每一 le：d之順向電壓（Forward v〇丨tage) 將Ik之降低，因此，原先施加於電晶體⑴之汲極電壓％ 200930154 將隨之增加，所以當電晶體Qi上之w越大，則 所消耗的功率與溫昇亦隨据古 基 日日體Q1 率。现之如同，進而降低電路整體的效 f發明内容】 有鑒於此，本發明將提供一種[肋之 法，係可減少LED驅動電路嘴鉍 玄°义置及其方 之電源效^ 較路她之功率，以料整體電路 一 τ二^ (目的本發明提供一種[ED驅動裝置，勺釭 二尸:陣列、一電源供應單元、複數：括 则測單元、—電壓選擇單元及減法單：電: 列，以提供該些咖串=連接該些咖串 路係分別連接該此le^L,丨 乍 複數個驅動電 流，及控制該些⑽串列之仙串列上之電 個別包括-電晶體，該通與截止，該些驅動電路係 之一；—雷 日日體之汲極係連接該些LED串列 ο 電阻，遠電阻之—端係連接該 電阻之另一端係接地 电曰曰體之源極，该 非反相輸入端係接收—= ^大器之 ，，至該電晶艘之源極;該二放= 大益之輪出端連接該電晶體 ^之間’違運异放 係個別連接該些電晶體之没“=個電^横測單元 接收該些電晶體之没極電壓=選擇單元係 該第一電壓信號係為該㈣二，信號，其中 之電壓。減法單元係接收該電;=電壓值最小 與該第一電壓作號應早凡之輪出電壓信號 波㈣電源供應單元之輪出電壓信號與 200930154 ，第-電壓信號相減以輸出„第二電壓信號 單兀’而該電源供應單元接收該第 源供應 輸出之工作電壓。 电-15戚後’即調整 為達上述目的，本發明再提出一種led背光 。 動方法’其步驟包括先彻—電源供應單元—"、之驅 ^ 陣列工作，其中該⑽陣列係包括複數你_Crystal Q1, second transistor Q2, and resistor R1. The first transistor is connected to the LED string 1U, and the first transistor is connected to the output terminal of the operational amplifier 0Π, the source of the transistor; (Source) is connected to the resistor R1. One end; and another mountain of resistance illusion is grounded. The non-inverting input of the operational amplifier OP1 is received - the hf' inverting input is connected to the source terminal of the transistor - Q1 and ^ R1. The 汲 extreme of the second transistor Q2 is connected between the output of the operational amplifier 〇ρι and the gate terminal of the first transistor Q1, and the gate of the second transistor receives a PWM dimming control signal, and the second The transistor is extremely grounded. ", , According to the above, the operational amplifier, the first transistor Q1 and the resistor R1 constitute a linear regulator (Linear 卯lat〇r), and the linear regulator compares the reference voltage Vref with the voltage drop of the resistor 藉 by the operational amplifier OP1 , used to limit the current 通过 through the first transistor Q1. Secondly, when the second electric body, the body Q2 is turned on (Turnon), the output terminal of the operational amplifier 0N, because the second transistor Q2 is grounded to make its output voltage zero, so that the first transistor = the turn-off state Therefore, there is no current flowing through the LED string ill. When the second transistor Q2 is in the off state, the output of the operational amplifier "〇ρι" will provide a potential to turn on the first transistor Q1 and maintain the drive current required for the LED string 111. However, conventionally known In the circuit architecture, each of the driving circuits 121 to 12n must use two transistors Q1 and Q2. As the number of LEDs is increased, the transistor needs to be added, so that the circuit cost is greatly increased. The increase of the time of the series 111 刼1, the forward voltage of each le:d reduces the Ik, so the threshold voltage %200930154 originally applied to the transistor (1) will increase, so When the w on the transistor Qi is larger, the power consumption and temperature rise are also in accordance with the Q1 rate of the celestial body. The present invention is similar to the effect of reducing the overall efficiency of the circuit. In view of this, the present invention will Providing a method of ribs, which can reduce the power of the LED driving circuit and the power supply of the side of the LED driving circuit, and the power of the circuit, to the overall circuit of the device, the object of the present invention provides an [ED driving device] , scoop two bodies: array, a power supply unit, plural Including the measuring unit, the voltage selecting unit and the subtracting list: electricity: column to provide the coffee strings = connecting the coffee string systems respectively connecting the LEDs, the plurality of driving currents, and controlling the plurality of (10) The series of wires on the string of congeners include - a transistor, the pass and cutoff, one of the drive circuit systems; - the thunder pole of the thunder body connects the LED strings ο, the resistance, the far resistance The other end of the resistor is connected to the source of the grounding electric body, and the non-inverting input terminal receives the source of the electric crystallizer, the second non-inverting input terminal; The round-out end is connected to the transistor ^ between the illegally-disconnected individual connecting the transistors. "=Electrical ^ Transverse unit receives the minimum voltage of the transistors = the selected unit is the first voltage The signal system is the (four) two, the signal, wherein the voltage is taken. The subtraction unit receives the electricity; the voltage value is minimum and the first voltage is set to be earlier than the voltage signal wave (4) the voltage output signal of the power supply unit and 200930154, the first voltage signal is subtracted to output "second voltage signal unit" and the electricity The supply unit receives the working voltage of the first source supply output. After the electric switch is adjusted to achieve the above purpose, the present invention further provides a LED backlight. The method includes the steps of “the first step—the power supply unit—" Drive the array to work, where the (10) array includes multiples of you _
串列；再分顺供-剛電壓錢給複數她動i^LEraD ❹ Ο 此 根據所接收之該電編虎 該此 LED串列之兜滅，及限制通過該些LED串列之 二 利用複數個__單元_軸,_電路與^LEj ::1 丨之3;由—電賴擇單元接收該些剩測單元所 偵測之電麗’並輸出—第—電壓信號，其中該第 號係為該些電壓_單元所痛測之電壓中，電壓值最= 電壓；利用-減法單元將該第—電壓信號與該電源供應單 =之輸出電屡信號相減，並輪出—第二電壓信號；最^該 電源供應單it根據該第二電壓信號調整輸出之該工作^ 壓。 為了能更進一步瞭解本發明為達成預定目的所採取 之技術、手段及功效，請參閱以下有關本發明之詳細說明 與附圖，相信本發明之目的、特徵與特點，當可由此得一 深入且具體之瞭解，然而所附圖式，僅提供參考與說明用， 並非用來對本發明加以限制者。 【實施方式】 請參閱第二圖’係為本發明LED背光電源之驅動裝置 的電路圖。本發明之LED背光電源之驅動裝置係包括電源 供應單元20、LED陣列21、複數個驅動電路221〜22η、複 200930154 . 數個電壓偵測單元241〜24η、電壓選擇單元25及減法單 元26。電源供應單元2〇係透過直流電力線23連接lex)陣 列21，以供LED陣列21工作所需之電壓電源。LED陣列 21係包括複數條LED串列211〜而每條LED串列211 〜21η係包括複數個LED。驅動電路221〜22η係個別連接 至各LED串列211〜21η，用以控制LED串列211〜21η上 之電流，及控制LED串列211〜21η上之LED的亮滅。 復參考第二圖，電源供應單元20為一串聯諧振轉換 窃（Series resonant converter，SRC)，本發明利用串聯 諧振轉換器提供LED陣列21工作所需之電壓。諧振轉換器 的功率開關可達成零電壓切換之功效，故可改善硬切式開 關直流電源供應器之缺陷。 # 各驅動笔路221〜22η係包括一運算放大器QP2i j、— 電晶體Q211及一電阻R21。電晶體q211之汲極係連接ΙΕΙ) 串列211〜21η其_之一，電晶體Q2n之閘極係連接運算 放大器0P211之輸出，而電晶體Q211之源極係連接電阻 ❹ 敗1之一端’其電阻R21之另一端係接地。運算放大器〇p2U 之非反相輸入端接收一 PWM電壓信號Vpl，而運算放大器 0P211之反相輸入端連接至電晶體Q211源極與電^R2i ^ 間。而上述之電晶體Q211係可為一場效應電晶體（Field effect transistor ’· FET)或雙極性接面電晶體（Bip〇lar junction transistor ; BJT)。 以LED串列211與其所連接之驅動電路221為例來說 明LED串列211〜21η上電流之控制，及其導通或截止Lm) 串列211〜21η之動作關係。在驅動電路221令，當運算放 大器0Ρ211之非反相輸入端接收之電壓信號為高 10 200930154 • Γ二;:Γ及電導通，⑽㈣電流⑵將通過串 串 ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , __unit_axis, _circuit and ^LEj::1 丨3; receive the singularity detected by the remaining unit by the sputum unit and output the -th voltage signal, wherein the number In the voltage measured by the voltage_unit, the voltage value is the most = voltage; the use-subtraction unit subtracts the first voltage signal from the power supply single = output signal, and turns out - second The voltage signal; the power supply unit it adjusts the output voltage of the output according to the second voltage signal. In order to further understand the technology, the means and the effect of the present invention in order to achieve the intended purpose, refer to the following detailed description of the invention and the accompanying drawings. The detailed description is to be understood as illustrative and not restrictive. [Embodiment] Please refer to Fig. 2' for a circuit diagram of a driving device for an LED backlight power supply of the present invention. The driving device for the LED backlight power supply of the present invention comprises a power supply unit 20, an LED array 21, a plurality of driving circuits 221 to 22n, a plurality of 200930154, a plurality of voltage detecting units 241 to 24n, a voltage selecting unit 25, and a subtracting unit 26. The power supply unit 2 is connected to the lex array 21 through the DC power line 23 for supplying the voltage power required for the operation of the LED array 21. The LED array 21 includes a plurality of LED strings 211 - and each of the LED strings 211 - 21 η includes a plurality of LEDs. The drive circuits 221 to 22n are individually connected to the respective LED strings 211 to 21n for controlling the currents on the LED strings 211 to 21n and controlling the LEDs on the LED strings 211 to 21n to be turned on and off. Referring back to the second figure, the power supply unit 20 is a series resonant converter (SRC). The present invention utilizes a series resonant converter to provide the voltage required for the operation of the LED array 21. The power switch of the resonant converter achieves zero voltage switching, which improves the defect of the hard-switching DC power supply. # Each of the driving pens 221 to 22n includes an operational amplifier QP2i j, a transistor Q211, and a resistor R21. The gate of the transistor q211 is connected to ΙΕΙ) one of the series 211 to 21η, the gate of the transistor Q2n is connected to the output of the operational amplifier OP211, and the source of the transistor Q211 is connected to the resistor 之一1 of one end' The other end of the resistor R21 is grounded. The non-inverting input of the operational amplifier 〇p2U receives a PWM voltage signal Vpl, and the inverting input of the operational amplifier 0P211 is connected to the source of the transistor Q211 and the voltage ^R2i^. The above-mentioned transistor Q211 can be a field effect transistor (FET) or a bipolar junction transistor (BJT). The LED string 211 and the driving circuit 221 to which it is connected are taken as an example to illustrate the control of the current on the LED series 211 to 21n, and the relationship between the conduction or the off Lm) series 211 to 21n. In the driving circuit 221, when the non-inverting input terminal of the operational amplifier 0Ρ211 receives the voltage signal high 10 200930154 • Γ2;: Γ and electrical conduction, (10) (four) current (2) will pass
• Li^串列及電阻，B r如A• Li^ string and resistor, B r as A
Tfc ° ^ pm v 肋串列為順向導通而發 二=:=::電_則無== P醫電觸加輸入至各二=，;=3放 =广，，各_路22121= ®之亮減，及限制各;^列trrtLE]^列211〜21n 各__，之ϋ1調t上能之電流’藉此達成 然而，隨LED串列21!操作時間之增長，每 = 因此’原先施加於電晶體叫Ϊ 則之增加’所以當電晶體_上之^越大， 了僻所雜的功率與溫昇亦隨之提高，因此发 咖^電源供應單元2〇所提供多餘之電壓㈣在電^ Λ ，驗，而產生功率消耗之問題，本發明LED背光带满"" 連接雷ί在各驅動電路221〜22n與LED串列21ϊ〜『ιΓ二 。莖偵測單元241〜24η，藉由電壓偵測單元24曰 f 電路221〜2211中電㈣_ 墼選擇單凡25則連接各電壓偵測單元24ΐ〜24 、 :,區動電路22卜22η中電晶體_〜Q21n之汲極= D在電壓選擇單元25接收各汲極電壓^後，將輪 號VS卜而第一電壓信號VS1 <系為各沒極電^ 電壓值最小的電壓；換言之，電壓選擇單元25 / 壓中，選擇一最小祕議輸出。減 貝]接收第—電壓信號VS1及電源供應單元2〇之輪出電 11 200930154 堅t號Vo再將兩個電壓相減後，輸出一第二 原供應單元20。電源供應單元划接收第二電壓信號 =2後，即可調整供給⑽陣列21之工作電屬。因此，本 案led _裝置藉由調整電源供應單元2()之輸出電麼 1!"減少因為LED ♦向偏壓之降低，導致電晶體 Q ll.n麼降增加之影響’進而提昇驅動電路之整體效 準〇 Ο ❿ 復參考第二圖’本發明LED背光電源之驅動裝置進一 步包t數位信號處理器（Digital Slgnal Pr。⑽。r;DSP) 。L制器27依據-調光時序責任週期Ts將簡電 聖信號Vp卜Vpn分別送至運算放大器〇p2i卜㈣^ ，相輸入端，以完成LED陣列21之調光、均流與驅動： 相移之控制目的。配合第二A圖，lrd陣列21之平ς 電流波形分別為IF1(ave)〜IF3(ave)，其中，工临二 驅動時間為（Kti，IF2(ave)之,_時間為心2， =:跡因此，調光時序責任職可由2Tfc ° ^ pm v Ribs are listed as compliant with the second =:=::Electric _ then no == P medical touch input to each two =,; = 3 put = wide, each _ road 22121 = ® light reduction, and limit each; ^ column trrtLE] ^ column 211 ~ 21n each __, then 调 1 t adjust the current on the 'turned on, however, with the LED string 21! Operation time increases, each = therefore 'The original application to the transistor called 增加 之 increase', so when the transistor _ on the ^ is larger, the confusing power and temperature rise will also increase, so the hair supply ^ power supply unit 2 〇 provide redundant The voltage (four) is in the power, the test, and the problem of power consumption, the LED backlight of the present invention is full "" connected to the lightning in each of the drive circuits 221~22n and the LED string 21ϊ~“ιΓ二. The stem detecting units 241 〜 24 η are connected to the voltage detecting units 24 ΐ 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 The drain of the crystal_~Q21n=D, after the voltage selection unit 25 receives each of the drain voltages ^, the wheel number VS and the first voltage signal VS1 < is the voltage at which the voltage value of each of the poleless voltages is the smallest; in other words, Voltage selection unit 25 / pressing, select a minimum secret output. The second power supply unit 20 is outputted after receiving the first voltage signal VS1 and the power supply unit 2's wheel discharge power 11 200930154. After the power supply unit receives the second voltage signal = 2, the operating power of the supply (10) array 21 can be adjusted. Therefore, in this case, the LED_device adjusts the output power of the power supply unit 2() by reducing the influence of the increase in the voltage of the transistor Q ll.n. The overall effect 〇Ο 参考 Refer to the second figure 'The driving device of the LED backlight power supply of the present invention further includes a digital signal processor (Digital Slgnal Pr. (10).r; DSP). The L controller 27 sends the simple electric signal Vp Bu Vpn to the operational amplifier 〇p2ib (4)^, the phase input terminal according to the dimming timing duty cycle Ts, to complete the dimming, current sharing and driving of the LED array 21: Move control purposes. In conjunction with the second A picture, the flat current waveforms of the lrd array 21 are IF1(ave)~IF3(ave), respectively, wherein the driving time is (Kti, IF2(ave), _time is the heart 2, = : Trace Therefore, the dimming timing responsibility can be 2
T 另二m(=)〜IF3(ave)驅動時間可設定為如2 L妨 代人⑴即可求得¥3 τ。其次，. Α圖’驅動時間tl的相位㈧可由公式⑴取得 θ\ 11 — * _ _ τ 因此，將驅動時間與調光 代入（2)即可求得度，亦即平任週』Ts=3r IF2(ave)120 度。再者，將 t2_ u :電^ IF1(ave)領謂 t扣τ與Ts=3r科 12 200930154 入（2)即可求得θ 2=120度 IF3(ave)120 度。 亦即平均電流IF2(ave)領前 在調光時序責任週期Ts之内，電源供鮮元2〇所需 Μ共之電流i〇(min)，即為平均電流⑻（㈣^脱（請) 由於该LED串列211〜21 ln之驅動電流係相移方式 :，此其I〇(min)不會降低至0A，亦即串聯諧振轉換 二不細作在空載狀態’因此可防止電源供應1元2生 輸出電壓漂移。 eT The other two m (=) ~ IF3 (ave) drive time can be set to 2 L to replace the person (1) to obtain ¥ 3 τ. Secondly, the phase of the driving time t1 (8) can be obtained by the formula (1) θ\ 11 — * _ _ τ Therefore, the driving time and the dimming can be obtained by substituting (2), that is, the flat week Ts=3r IF2 (ave) 120 degrees. Furthermore, t2_ u : electric ^ IF1 (ave) collar t buckle τ and Ts = 3r section 12 200930154 into (2) can be found θ 2 = 120 degrees IF3 (ave) 120 degrees. That is, the average current IF2 (ave) is within the dimming timing duty cycle Ts, and the current required for the power supply is 2〇(min), which is the average current (8) ((4) ^ off (please) Since the driving current of the LED series 211 to 21 ln is phase-shifted, the I 〇 (min) is not reduced to 0 A, that is, the series resonant conversion is not fined in the no-load state. Element 2 output voltage drift. e
再者/由於調光時序責任週期以七，故可依據公式 取得最小調光責任週期Dmin為33.33%。 -L— 1 7^" = 3~ = ^min = 33.33 % -..(3) ϋ第—圖’參考第二B ®，為本發明使用的DSP丰 之軟體流程圖。#程式開始後，色彩感測器U .' ‘t測月光模組（未標示）所散發之紅色、綠色與羞 ，2 ’進而將光線轉換為三原色類比信號(S100)，料 爲相银t制器27°DSP控制器27將該三原色類比信號轉相 isi⑽Γ之數位錢（si02)之後，再進行信號判勤 。切健號大於預設之參考值時，職少調光爽 # ，虽數位k號小於預設之參考值時，則增加朝 任觀。進而再將調光時序責任·利用相移歩 成LED陣列21分相驅動（S108)。因此，利用第 和制方^程’即可改善—般背光模組白平衡控制採用P; 嶋;雜度，進而穩定串騎振轉換器名 接著，以包括紅光、綠光、及藍光LED p參列（各別係 200930154 如前述之LED陣列21)做背光之驅動電路來說明ρ·電壓 信號之操作原理。Furthermore, since the duty cycle of the dimming timing is seven, the minimum dimming duty cycle Dmin can be 33.33% according to the formula. -L - 1 7^" = 3~ = ^min = 33.33 % -..(3) ϋ第图图' refers to the second B ® , which is the flow chart of the DSP software used in the present invention. After the program starts, the color sensor U.' 't measures the red, green and shame emitted by the moonlight module (not labeled), 2' and then converts the light into a three-primary analog signal (S100), which is expected to be silver The controller 27° DSP controller 27 converts the three primary color analog signals into the digits (si02) of isi (10), and then performs signal judgment. When the cut number is greater than the preset reference value, the job is less than the default value. Although the number k is less than the preset reference value, the orientation is increased. Further, the dimming timing responsibility is further phase-shifted by the phase shift into the LED array 21 (S108). Therefore, the use of the first and the second method can improve the white balance control of the backlight module adopts P; 嶋; noise, and then stabilizes the string riding transducer name, followed by red, green, and blue LEDs. The p-column (each of which is 200930154 as described above) is used as a backlight driving circuit to explain the operation principle of the ρ·voltage signal.
請複參閱第三圖，係為本發明PWM電壓信號供應電路 之功能方塊圖’其中紅光LED感測元件30、綠光LED感測 元件31與藍光LED感測元件32，感測紅光LED陣列、綠 光LED陣列與藍光LED陣列產生之亮度後，分別輸出電魘 VRout、VGout、及VBout給數位信號處理器33。數位信號 處理益33根據電麗VRout、VGout及VBout控制PWM電壓 信號 Vp(R)、Vp(G)、與 Vp(B)之貴任週期（Duty Cycle)， 再分別將PWM電壓信號Vp(R)、Vp(G)、與印（幻輸出至紅 光驅動電路30卜30η、綠光驅動電路4〇1〜40η、藍光驅動電 路501〜5On (各驅動電路分別如前述驅動電路221〜22η )， 藉此控制紅光、綠光、及藍光LED陣列之光源。 接著請參閱第四圖，係為本發明LED背光電源之驅動 方法流程圖。首先利用電源供應單元2 〇輸出—工作電壓驅 動LED陣列21，而LED陣列21係包括複數條LED串列21工 〜21n(如第四圖步驟S401)。利用Dsp控制器27分別提 供- P醫電屢信號Vp給各驅動電路221〜22以如第四圖 步驟S403)。接著驅動電路221〜22n根據所接收之觸電 壓信號VP去控制μ料列211〜…之亮減，及限制流 過:亥些LED串列211〜21n之電流（如第四圖步驟S4〇5)。 然後利用電單元241〜24n制,轉電路221〜 與LED串列211〜21n間之電屡（如第四圖步驟s·)。電 麼選擇單元25接收電㈣測單元241〜24n所㈣^ 壓’並輸出-第-電壓㈣m，而第一電壓 為電㈣測單元24】〜施所偵測之電壓中㈣值最小^ 14 200930154 電壓（如第四圖步驟S4〇9)。利用 '信_與電源供應單元20之輸出電第〜電壓 輸出第二電壓信號鄉第四圖步二滅’並 應單元20根據第二電壓信號VS2調整輸出之工 電源供 第四圖步驟S413)。 輸出之工作電壓（如 、综上所述，本發明之L仙n 由調整電源供應單元之輸出電壓信號 ❹==功率損失’故可達到 m 功效。其一人，魏串列藉由PWM調光作號相t路效率 故可防 盗，其負载（LED陣列）為空载操作時，所造 振轉換 漂移，藉此讓電源供應單元提供一穩定輪出=電f LED陣列。 下電壓驅動 上所述者’僅為本發明其中的較佳實施例而 用來限定本發明的實施範圍；即凡依本發 ’亚非 所作的均等變化與修飾，皆為本發明專利範圍^，，辈巳圍 ❹ 【圖式簡單說明】 義盍° 第一圖為習知均流及？簡調光電路之電路圖· 第二圖為本發明LED背光電源之驅動步 圖； 動裝置的電路方塊 第二A圖為本發明LED陣列之平均驅動 圖； 勒寬流波形示意 第二B圖為本發明使用的Dsp控制 程圖； 以木用之軟體流 第三圖為本發明PWM電壓信號供應 ^功能方塊 15 200930154 圖；及 第四圖為本發明LED背光電源之驅動方法步驟流程 圖。 【主要元件符號說明】， 習知： 電源供應單元10 LED陣列11 LED串列Please refer to the third figure, which is a functional block diagram of the PWM voltage signal supply circuit of the present invention. The red LED sensing component 30, the green LED sensing component 31 and the blue LED sensing component 32, and the red LED are sensed. After the brightness generated by the array, the green LED array and the blue LED array, the power VRout, VGout, and VBout are output to the digital signal processor 33, respectively. The digital signal processing benefit 33 controls the PWM voltage signals Vp(R), Vp(G), and Vp(B) according to the VRout, VGout and VBout, and then respectively sets the PWM voltage signal Vp(R). ), Vp (G), and imprint (phantom output to red light driving circuit 30 30n, green light driving circuit 4〇1 to 40n, blue driving circuits 501 to 5On (each driving circuit is as described above for driving circuits 221 to 22n) , thereby controlling the light source of the red, green, and blue LED arrays. Next, please refer to the fourth figure, which is a flowchart of the driving method of the LED backlight power supply of the present invention. First, the power supply unit 2 〇 output-operating voltage is used to drive the LED. The array 21, and the LED array 21 includes a plurality of LED strings 21 to 21n (as in the fourth step S401). The Dsp controller 27 is used to provide a -P medical signal Vp to each of the driving circuits 221 to 22, for example. The fourth figure is step S403). Then, the driving circuits 221 22 22n control the light-reduction of the μ column 211 〜 〜 according to the received touch voltage signal VP, and limit the current flowing through the LED arrays 211 21 21n (eg, step S4 〇 5 in the fourth figure). ). Then, the electric circuit units 241 to 24n are used to make the electric circuit between the circuit 221 and the LED series 211 to 21n (as in the fourth step s·). The electric selecting unit 25 receives the electric (four) measuring units 241~24n (four) and presses and outputs the -th voltage (four) m, and the first voltage is the electric (four) measuring unit 24] the voltage detected by the (four) value is the smallest ^ 14 200930154 Voltage (as in the fourth step, step S4〇9). Using the 'letter_and the power supply unit 20's output power to the second voltage signal, the second step of the second voltage signal, and the unit 20 adjusts the output power according to the second voltage signal VS2 for the fourth step (S413) . The working voltage of the output (for example, in the above, the L n n of the present invention is adjusted by the output voltage signal of the power supply unit ❹== power loss ′, so that the m effect can be achieved. One person, the Wei series is dimmed by PWM The phase-to-phase efficiency is anti-theft, and the load (LED array) is used for no-load operation, and the vibration is converted and drifted, thereby allowing the power supply unit to provide a stable turn-out = electric f LED array. The description of the present invention is only intended to limit the scope of implementation of the present invention; that is, the equivalent variations and modifications made by the present invention are the scope of the invention. ❹ [Simple diagram of the diagram] 盍 盍 ° The first diagram is the circuit diagram of the conventional averaging current and simple dimming circuit. The second diagram is the driving step diagram of the LED backlight power supply of the present invention; The average driving diagram of the LED array of the present invention; the second wide waveform shows the Dsp control diagram used in the present invention; the third diagram of the soft flow of the wood is the PWM voltage signal supply of the present invention^ function block 15 200930154 Figure; and the fourth picture The flow chart of the driving method of the LED backlight power supply of the present invention. [Main component symbol description], conventional: power supply unit 10 LED array 11 LED series
驅動電路121〜12η 運算放大器0Ρ1 第一電晶體Q1 第二電晶體Q2 電阻R1 電流II 直流電力線13 參考電壓Vref 本發明： 電源供應單元20 LED陣列21 LED串列211〜21η 驅動電路221〜22η 運算放大器0Ρ21卜0Ρ21η 電晶體Q211〜Q21n 電阻R21 16 200930154 - 直流電力線23 電壓偵測單元241〜24η 電壓選擇單元25 減法單元26 DSP控制器27 PWM電壓信號Vpl〜Vpn P丽電壓信號 Vp(R)、Vp(G)、Vp(B) _ 輸出電壓信號Vo 第一電壓信號VS1 第二電壓信號VS2 紅光感測元件30 綠光感測元件31 藍光感測元件32 數位信號處理器33 紅光LED驅動電路30卜30η φ 綠光LED驅動電路401〜40η 藍光光LED驅動電路5(U〜50η 17Driving circuit 121~12n Operational amplifier 0Ρ1 First transistor Q1 Second transistor Q2 Resistance R1 Current II DC power line 13 Reference voltage Vref The present invention: Power supply unit 20 LED array 21 LED string 211~21η Drive circuit 221~22η Operation Amplifier 0Ρ21卜0Ρ21η Transistor Q211~Q21n Resistor R21 16 200930154 - DC power line 23 Voltage detecting unit 241~24n Voltage selecting unit 25 Subtracting unit 26 DSP controller 27 PWM voltage signal Vpl~Vpn P Li voltage signal Vp(R), Vp(G), Vp(B) _ output voltage signal Vo first voltage signal VS1 second voltage signal VS2 red light sensing element 30 green light sensing element 31 blue light sensing element 32 digital signal processor 33 red light LED driver Circuit 30 30 η φ green LED driving circuit 401 ～ 40 η blue light LED driving circuit 5 (U 〜 50 η 17