M392419 五、新型說明： 【新型所屬之技術領域】 [0001] 本新型涉及背光源驅動系統，特別涉及一種發光二極體 背光源驅動系統。 【先前技術】 [0002] 在高對比與環保要求下，發光二極體取代冷陰極螢光燈 成為液晶顯示屏背光源技術是時下的發展趨勢。在液晶 顯示屏中，發光二極體一般採用多區域或多串並聯的架 構。在此架構下，多採用直流/直流轉換器加多通道定電 流驅動器的方式驅動發光二極體工作。為達到最佳的轉 換效率，多通道定電流驅動器輸出一個調整Jf壓，用於 調整直流/直流轉換器的輸出電壓。然而，為了配合畫面 達到不同亮度輸出，發光二極體的驅動電流需操作在幾 個不同的設定值，多通道定電流驅動器輸出的調整電壓 需調整的範圍也相應變大，而這將影響轉換效率。 【新型内容】 [0003] 有鑑於此，需提供一種發光二極體背光源驅動系統，在 調節發光二極體的驅動電流時使效率最佳化。 [0004] 一種發光二極體背光源驅動系統，用於驅動至少一個發 光二極體陣列，該發光二極體陣列包括多個並聯的發光 二極體串。該發光二極體背光源驅動系統包括至少一個 升壓電源轉換電路、至少一個多通道定電流驅動電路、 至少一個控制器、至少一個分壓電路及補償電壓產生電 路。該升壓電源轉換電路用於將直流電源訊號升壓，以 表單編號A0101 第3頁/共19頁 M392419 驅動該發光二極體陣列。該控制器用於控制該升壓電源 轉換電路。該多通道定電流驅動電路用於控制流經該發 光二極體陣列的電流，並輸出調節電壓至該控制器，以 調節該升壓電源轉換電路的輸出電壓。該分壓電路用於 對該升壓電源轉換電路的輸出電壓分壓，並產生迴授電 壓至該控制器。該補償電壓產生電路與該分壓電路相連 ，用於根據至少一個模式選擇訊號產生補償電壓，以改 變該迴授電壓。其中，該控制器根據該迴授電壓及該調 節電壓，控制該升壓電源轉換電路的輸出電壓。 [0005] 優選地，該分壓電路包括第一電阻、第二電阻及第三電 阻。該第二電阻與該第一電阻依次串聯於該升壓電源轉 換電路的輸出端與地之間。該第三電阻一端接收該調節 電壓，一端連接於該第一電阻與該第二電阻之間。 [0006] 優選地，該迴授電壓為該第二電阻上的電壓。 [0007] 優選地，該補償電壓產生電路包括第一開關元件、第二 開關元件、第四電阻及第五電阻。該第一開關元件包括 控制端、輸入端及輸出端，該控制端接收第一模式選擇 訊號，該輸入端接地。該第二開關元件包括控制端、輸 入端及輸出端，該控制端接收第二模式選擇訊號，該輸 入端接地。該第四電阻一端連接該第一開關元件的輸出 端。該第五電阻一端連接該第二開關元件的輸出端，另 一端連接至該第四電阻的另一端，並連接至該第一電阻 與該第二電阻之間。 [0008] 優選地，該第一開關元件與該第二開關元件均為N型金屬 表單編號A0101 第4頁/共19頁 M392419 氧化物半導體場效應管，該控制端均為閘極，該輸入端 均為源極，該輸出端均為汲極。 [0009] 優選地，該發光二極體背光源驅動系統驅動多個發光二 極體陣列，且每個發光二極體陣列對應一個升壓電源轉 換電路、一個多通道定電流驅動電路、一個控制器及一 個分壓電路。 [0010] 優選地，該補償電壓產生電路包括第三開關元件、第四 開關元件、第六電阻、第七電阻、第八電阻、第九電阻 及電壓隨耦器。該第三開關元件包括控制端、輸入端及 輸出端，該控制端接收第一模式選擇訊號，該輸入端接 地。該第四開關元件包括控制端、輸入端及輪出端，該 控制端接收第二模式選擇訊號，該輸入端接地。該第六 電阻一端連接該第三開關元件的輸出端。該第七電阻一 端連接該第四開關元件的輸出端，另一端連接至該第六 電阻的另一端。該第九電阻與該第八電阻串聯於參考電 壓與地之間，該第九電阻與該第八電阻的公共節點連接 至該第六電阻與該第七電阻的另一端。該電壓隨耦器正 向輸入端連接至該第八電阻與該第九電阻之間，輸出端 連接至每一個分壓電路的第一電阻與第二電阻之間。 [0011] 優選地，該第三開關元件與該第四開關元件均為N型金屬 氧化物半導體場效應管，該控制端均為閘極，該輸入端 均為源極，該輸出端均為汲極。 [0012] 優選地，該補償電壓產生電路包括微處理器，該微處理 器接收第一模式選擇訊號與第二模式選擇訊號，產生該 表單编號A0101 第5頁/共19頁 M392419 補償電壓並將該補償電壓疊加至該第二電阻上β [0013] 上述發光二極體背光源驅動系統利用補償電壓產生電路 產生合適的補償電壓來改變分壓電路的迴授電壓，以改 變升壓電源轉換電路的輸出電壓設定點，從而使多通道 定電流驅動電路的調節電壓的調整範圍減小，調整精確 度變高’可真正調至最佳值進而達到效率最佳化。 【實施方式】 [0014] 圖1為本新型一實施方式中發光二極體背光源驅動系統 的示意圖》在本實施方式中，發光二極體背光源驅動系 統10用於驅動至少一個發光二極體陣列20，其包括至少 一個升壓電源轉換電路100、至少一個多通道定電流驅動 電路110、至少一個控制器120、至少一個分壓電路13〇 及補償電壓產生電路140。在本實施方式中，發光二極體 陣列20包括多個相互並聯的發光二極體串2〇〇，每個發光 二極體串200包括多個相互串聯的發光二極體。在本實施 方式中，升壓電源轉換電路100、多通道定電流驅動電路 110、控制器120、分壓電路130與發光二極體陣列2〇的 數目相同，即每個發光二極體陣列2 〇對應一個升壓電源 轉換電路100、一個多通道定電流驅動電路11〇、一個控 制器120及一個分壓電路130 » [0015] 升壓電源轉換電路100用於將直流電源訊號vin升壓，並 輸出電壓Vout以驅動發光二極體陣列2〇。控制器120用 於控制升壓電源轉換電路1〇〇。多通道定電流驅動電路 110用於控制發光二極體陣列20的電流，並輸出調節電壓 Vo至控制器120，以調節升壓電源轉換電路1〇〇的輸出電 表單编號A0101 第6頁/共19頁 M392419 ^v〇ut，從而控制發光二極體陣列20的電流恒定，不會 產生閃爍。M392419 V. New Description: [New Technology Field] [0001] The present invention relates to a backlight driving system, and more particularly to a light emitting diode backlight driving system. [Prior Art] [0002] Under high contrast and environmental protection requirements, the replacement of cold cathode fluorescent lamps by light-emitting diodes has become a current trend in liquid crystal display backlight technology. In the liquid crystal display, the light-emitting diodes generally adopt a multi-region or multi-parallel arrangement. Under this architecture, the DC/DC converter and the multi-channel constant current driver are often used to drive the LED operation. For optimum conversion efficiency, the multi-channel constant current driver outputs an adjusted Jf voltage that is used to adjust the output voltage of the DC/DC converter. However, in order to match the screen to achieve different brightness output, the driving current of the LED needs to be operated at several different setting values, and the range of the adjustment voltage of the multi-channel constant current driver output needs to be adjusted accordingly, which will affect the conversion. effectiveness. [New Content] [0003] In view of the above, it is desirable to provide a light-emitting diode backlight driving system that optimizes efficiency when adjusting the driving current of the light-emitting diode. [0004] A light emitting diode backlight driving system for driving at least one light emitting diode array, the light emitting diode array comprising a plurality of parallel light emitting diode strings. The light emitting diode backlight drive system includes at least one boost power conversion circuit, at least one multi-channel constant current drive circuit, at least one controller, at least one voltage dividing circuit, and a compensation voltage generating circuit. The boost power conversion circuit is used to boost the DC power signal, and the LED array is driven by Form No. A0101, page 3 / 19 M392419. The controller is used to control the boost power conversion circuit. The multi-channel constant current drive circuit is configured to control a current flowing through the light-emitting diode array and output a regulated voltage to the controller to adjust an output voltage of the boost power conversion circuit. The voltage dividing circuit is configured to divide the output voltage of the boosting power conversion circuit and generate a feedback voltage to the controller. The compensation voltage generating circuit is connected to the voltage dividing circuit for generating a compensation voltage according to at least one mode selection signal to change the feedback voltage. The controller controls the output voltage of the boosting power conversion circuit according to the feedback voltage and the adjustment voltage. [0005] Preferably, the voltage dividing circuit includes a first resistor, a second resistor, and a third resistor. The second resistor and the first resistor are sequentially connected in series between the output of the boosting power conversion circuit and the ground. The third resistor receives the adjustment voltage at one end, and one end is connected between the first resistor and the second resistor. [0006] Preferably, the feedback voltage is a voltage on the second resistor. Preferably, the compensation voltage generating circuit includes a first switching element, a second switching element, a fourth resistor, and a fifth resistor. The first switching component includes a control terminal, an input terminal and an output terminal, and the control terminal receives the first mode selection signal, and the input terminal is grounded. The second switching element includes a control terminal, an input terminal and an output terminal, and the control terminal receives the second mode selection signal, and the input terminal is grounded. One end of the fourth resistor is connected to the output end of the first switching element. The fifth resistor is connected at one end to the output end of the second switching element, and the other end is connected to the other end of the fourth resistor, and is connected between the first resistor and the second resistor. [0008] Preferably, the first switching element and the second switching element are N-type metal form number A0101, page 4 / 19 pages, M392419 oxide semiconductor field effect transistor, the control end is a gate, the input The terminals are all sources, and the outputs are all drains. [0009] Preferably, the LED backlight driving system drives a plurality of LED arrays, and each LED array corresponds to a boost power conversion circuit, a multi-channel constant current driving circuit, and a control And a voltage divider circuit. [0010] Preferably, the compensation voltage generating circuit includes a third switching element, a fourth switching element, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, and a voltage follower. The third switching element includes a control terminal, an input terminal and an output terminal, and the control terminal receives the first mode selection signal, and the input terminal is grounded. The fourth switching element includes a control end, an input end and a wheel output end, and the control end receives the second mode selection signal, and the input end is grounded. One end of the sixth resistor is connected to the output end of the third switching element. The seventh resistor is connected to the output end of the fourth switching element, and the other end is connected to the other end of the sixth resistor. The ninth resistor and the eighth resistor are connected in series between a reference voltage and a ground, and the ninth resistor and the common node of the eighth resistor are connected to the sixth resistor and the other end of the seventh resistor. The voltage is coupled to the forward input of the coupler between the eighth resistor and the ninth resistor, and the output is coupled between the first resistor and the second resistor of each voltage divider circuit. [0011] Preferably, the third switching element and the fourth switching element are both N-type metal oxide semiconductor field effect transistors, the control ends are gates, and the input ends are all sources, and the output ends are all Bungee jumping. [0012] Preferably, the compensation voltage generating circuit comprises a microprocessor, and the microprocessor receives the first mode selection signal and the second mode selection signal, and generates the form number A0101 page 5 / 19 pages M392419 compensation voltage and Superimposing the compensation voltage on the second resistor β [0013] The above-mentioned LED backlight driving system uses a compensation voltage generating circuit to generate a suitable compensation voltage to change the feedback voltage of the voltage dividing circuit to change the boosting power supply. The output voltage set point of the conversion circuit is such that the adjustment range of the adjustment voltage of the multi-channel constant current drive circuit is reduced, and the adjustment accuracy becomes high, which can be truly adjusted to an optimum value to achieve efficiency optimization. [Embodiment] FIG. 1 is a schematic diagram of a backlight driving system for a light-emitting diode according to an embodiment of the present invention. In the present embodiment, a backlight driving system 10 for driving a light-emitting diode is used to drive at least one light-emitting diode. The body array 20 includes at least one boost power conversion circuit 100, at least one multi-channel constant current drive circuit 110, at least one controller 120, at least one voltage dividing circuit 13A, and a compensation voltage generating circuit 140. In the present embodiment, the light emitting diode array 20 includes a plurality of light emitting diode strings 2 并联 in parallel with each other, and each of the light emitting diode strings 200 includes a plurality of light emitting diodes connected in series with each other. In the present embodiment, the boosting power conversion circuit 100, the multi-channel constant current driving circuit 110, the controller 120, and the voltage dividing circuit 130 are the same as the number of the LED arrays 2, that is, each of the LED arrays. 2 〇 corresponds to a boost power conversion circuit 100, a multi-channel constant current drive circuit 11 〇, a controller 120 and a voltage divider circuit 130 » [0015] The boost power conversion circuit 100 is used to boost the DC power signal vin The voltage is output and Vout is output to drive the LED array 2〇. The controller 120 is for controlling the boost power conversion circuit 1〇〇. The multi-channel constant current driving circuit 110 is configured to control the current of the LED array 20, and output the regulating voltage Vo to the controller 120 to adjust the output of the boosting power conversion circuit 1A. A0101 Page 6 / A total of 19 pages M392419 ^v〇ut, so that the current of the LED array 20 is controlled to be constant without flicker.
[0016]分壓電路130用於對升壓電源轉換電路1〇〇的輸出電壓 v〇ut分壓’並產生迴授電壓”至控制器12〇。補償電壓 產生電路140與分壓電路130相連，用於根據至少一個模 式選擇訊號產生補償電磨Voffset，以改變迴授電屋Vp 。在本實施方式中，控制器120根據迴授電壓Vp及調節電 壓Vo，控制升壓電源轉換電路1〇〇的輸出電壓v〇ut。模 式選擇訊號可由開關/按紐等方式輸入。 [0017][0016] The voltage dividing circuit 130 is configured to divide the output voltage v〇ut of the boosting power conversion circuit 1〇〇 and generate a feedback voltage to the controller 12. The compensation voltage generating circuit 140 and the voltage dividing circuit The 130 is connected to generate a compensation electric grinder Voffset according to the at least one mode selection signal to change the feedback electric house Vp. In the embodiment, the controller 120 controls the boost power conversion circuit according to the feedback voltage Vp and the adjustment voltage Vo. 1〇〇 output voltage v〇ut. The mode selection signal can be input by switch/button, etc. [0017]
在本實施方式中，為了配合畫面達到不同亮度輸出，發 光二極體陣列2〇的驅動電流需操作在幾個不同的設定值 ’例如’驅動電流分別為3〇ibA、60mA、9〇πιΑ及120mA， 則升壓電源轉換電路100的輸出電壓v〇ut分別為27V、 30V、33V、36V。若發光二極體陣列2〇的驅動電流需改 變，例如，從30mA到60mA，通過輸入對應的模式選擇訊 號’使補償電壓產生電路140產生合適的補償電壓v〇ff_ set，以改變分壓電路13Q的迴授錢Vp，從而改變升壓 電源轉換電路⑽的輸出電壓VGUt設定點例如，從m 至29V。如此’财通道定電流驅動電路的調節電壓 V〇的調整範圍僅為1V，相較于未增加補償電壓產生電路 140前的3V，調整範圍變小，因而精確度較高，可真正調 至最佳值進而達到致率最佳化，並降低多通道定 電流驅 動電路11Q的溫度。在本實施方式卜心模式選擇訊號 的個數為N ’驅動電流設定值個數為M，。 在本實施方式巾，㈣料13G_電 圖 睹Amm 〜μ "主 表單編號A0101 第7頁/共19頁 [0018] M392419 2至圖4所示，分壓電路130包括第一至第三電阻R1、R2 及R3。第一電阻R1及第二電阻R2依次串聯於升壓電源轉 換電路100的輸出端與地之間，迴授電壓Vp為第二電阻上 R2的電壓。第三電阻R3—端接收調節電壓Vo，一端連接 於第一電阻R1與第二電阻R2之間。在本新型的其它實施 方式中，分壓電路130也可利用電容或二極體等實現。 [0019] 圖2所示為本新型第一實施方式中發光二極體背光源驅動 系統10的具體電路圖。在本實施方式中，補償電壓產生 電路140包括第一開關元件Q1、第二開關元件Q2、第四電 阻R4及第五電阻R5。第一開關元件Q1與第二開關元件Q2 分別包括控制端、輸入端及輸出端，該控制端分別接收 第一模式選擇訊號及第二模式選擇訊號，該輸入端接地 ，該輸出端分別對應連接第四電阻R4的一端與第五電阻 R5的一端。第四電阻R4與第五電阻R5的另一端相互連接 ，並共同連接至分壓電路130的第一電阻R1與第二電阻R2 之間。在本實施方式中，第一開關元件Q1與第二開關元 件Q2均為N型金屬氧化物半導體場效應管，該控制端均為 閘極，該輸入端均為源極，該輸出端均為汲極。第四電 阻R4與第五電阻R5的阻值不同。 [0020] 通過向第一開關元件Q1與第二開關元件Q2輸入第一模式 選擇訊號與第二模式選擇訊號，控制第一開關元件Q1與 第二開關元件Q2的導通與截止，從而切換分壓電路130的 第二電阻R2的並聯電阻，從而改變迴授電壓Vp。 [0021] 第一模式選擇訊號與第二模式選擇訊號為邏輯高低電平 訊號，例如，邏輯高電平訊號為5V，邏輯低電平訊號為 表單編號A0101 第8頁/共19頁 M392419 ον。若第一模式選擇訊號與第二模式選擇訊號其中至少 一個為邏輯高電平訊號，則第一開關元件Q1與第二開關 元件Q2至少一個導通，因而第四電阻R4與第五電阻R5至 少一個與第二電阻R2並聯，使得第一電阻R1上的分壓變 大，使得迴授電壓Vp較小。若第一模式選擇訊號與第二 模式選擇訊號均為邏輯低電平訊號，則第一開關元件Q1 與第二開關元件Q2均截止，無電阻與第二電阻R2並聯， 此時迴授電壓Vp較大。如此，可根據不同的驅動電流需 求，輸入對應的模式選擇訊號，改變迴授電壓Vp，從而 對應改變升壓電源轉換電路1 00的輸出電壓Vout的設定點 ，降低多通道定電流驅動電路110的調節電壓Vo的調整範 圍。 [0022] 在圖2中，發光二極體陣列20的數量為一個，利用第一實 施方式中的補償電壓產生電路140實現容易，且電路簡單 〇 [0023] 圖3所示為本新型第二實施方式中發光二極體背光源驅動 系統10的具體電路圖。在本實施方式中，發光二極體背 光源驅動系統10用於驅動多個發光二極體陣列20、21， 其中圖3中只示出兩個進行說明。發光二極體陣列20對應 升壓電源轉換電路100、多通道定電流驅動電路110、控 制器120及分壓電路130，發光二極體陣列21對應升壓電 源轉換電路101、多通道定電流驅動電路111、控制器 121及分壓電路131，且電路架構與連接關係同圖2中的相 同，此處不再贅述。發光二極體背光源驅動系統10包括 補償電壓產生電路140’ ，補償電壓產生電路140’ 包括 表單編號A0101 第9頁/共19頁 M392419 第二開關元件Q3、第四開關元件Q4、第六電阻R6及第七 電阻R7、第八電阻R8、第九電阻R9及電壓隨輕器1400。 弟二開關元件Q3、第四開關元件Q4、第六電阻R6及第七 電阻R7的連接關係同圖2中補償電壓產生電路14〇的連接 關係相同，此處不再贅述。第八電阻R8與第九電阻R9串 聯於參考電壓Vcc與地之間’且公共節點連接至第六電阻 R6與第七電阻R7的另一端。電壓隨耦器14〇〇的正向輸入 知連接至第八電阻R8與第九電阻R9之間，輸出端經由第 十電阻R10連接至每一組分壓電路130、131的第一電阻 R1與第二電阻R2之間，用於輸出補償電壓v〇ffset。電 壓隨耦器1400用於穩定其補償電壓voffse1:，使其補償 電壓Voffset不因負載而改變。 [0024] 在本實施方式中，通過輸入第一模式選擇訊號與第二模 式選擇訊號，控制第三開關Q3與第四開關Q4的導通截止 ’以改變與第九電阻R9的並聯電阻，從而改變第九電阻 R9的分壓’即改變電壓隨耦器14〇〇輸出的補償電壓 Voffset。如此，通過改變補償電壓v〇ffset，來改變分 壓電路130的迴授電壓Vp，從而改變升壓電源轉換電路 100的輸出電壓Vout的設定點，降低多通道定電流驅動電 路110的調節電壓Vo的調整範圍。本實施方式中的補償電 壓產生電路140’可穩定其補償電壓v〇ffset，適合於有 多個發光二極體陣列2〇的情況。 [0025] 圖4所示為本新型第三實施方式中發光二極體背光源驅動 系統10的具體電路圖》在本實施方式中，發光二極體背 光源驅動系統10與圖2的區別在於，補償電壓產生電路由 表單編號A0101 第10頁/共19頁 M392419 微處理器140’ ’實現。微處理器140’ ’接收第一模式 選擇訊號與第二模式選擇訊號，相應產生補償電壓 Vof fset並通過第十一電阻R11將補償電壓Vof fset疊加 至第二電阻R2上。本實施方式中的補償電壓產生電路140 ’’應用于設計時有用到單晶片的設計中。 [0026] 上述發光二極體背光源驅動系統10利用補償電壓產生電 路140產生合適的補償電壓Voffset來改變分壓電路130 的迴授電壓Vp，以改變升壓電源轉換電路100的輸出電壓 Vout設定點，從而使多通道定電流驅動電路110的調節電 壓Vo的調整範圍減小，調整精確度變高，可真正調至最 佳值進而達到效率最佳化，且可降低多通道定電流驅動 電路11 0的溫度。 [0027] 综上所述，本新型符合新型專利要件，爰依法提出專利 申請。惟，以上所述者僅為本新型之較佳實施例，舉凡 熟悉本案技藝之人士，在爰依本案新型精神所作之等效 修飾或變化，皆應包含於以下之申請專利範圍内。 【圖式簡單說明】 [0028] 圖1為本新型一實施方式中發光二極體背光源驅動系統的 不意圖， [0029] 圖2為本新型第一實施方式中發光二極體背光源驅動系統 的電路圖； [0030] 圖3為本新型第二實施方式中發光二極體背光源驅動系統 的電路圖；及 [0031] 圖4為本新型第三實施方式中發光二極體背光源驅動系統 表單编號A0101 第11頁/共19頁 M392419 的電路圖。 【主要元件符號說明】 [0032] 發光二極體背光源驅動系統：10 [0033] 升壓電源轉換電路：1 0 0、1 0 1 [0034] 多通道定電流驅動電路：110、111 [0035] 控制器：120、121 [0036] 分壓電路：130、131 [0037] 補償電壓產生電路：140、140’ [0038] 微處理器：140’ ’ [0039] 發光二極體陣列：20、21 [0040] 發光二極體串：200、210 [0041] 直流電源訊號：Vi η [0042] 輸出電壓：Vout [0043] 迴授電壓：Vp [0044] 調節電壓：Vo [0045] 參考電壓：Vcc [0046] 補償電壓：Vof fset [0047] 第一至第十一電阻：R1〜Rll [0048] 第一至第四開關：Q1〜Q4 表單編號A0101 第12頁/共19頁In the present embodiment, in order to achieve different brightness output in accordance with the screen, the driving current of the LED array 2〇 needs to be operated at several different setting values, for example, the driving currents are respectively 3〇ibA, 60mA, 9〇πιΑ and At 120 mA, the output voltage v〇ut of the boost power conversion circuit 100 is 27V, 30V, 33V, and 36V, respectively. If the driving current of the LED array 2〇 needs to be changed, for example, from 30 mA to 60 mA, the compensation voltage generating circuit 140 generates a suitable compensation voltage v〇ff_set by inputting a corresponding mode selection signal 'to change the partial piezoelectricity. The road 13Q returns the money Vp, thereby changing the output voltage VGUt set point of the boost power conversion circuit (10), for example, from m to 29V. Thus, the adjustment range of the regulation voltage V〇 of the constant current drive circuit is only 1V, and the adjustment range becomes smaller than that of the 3V before the compensation voltage generation circuit 140 is not increased, so that the accuracy is high, and the adjustment can be truly maximized. The optimum value further optimizes the rate and lowers the temperature of the multi-channel constant current drive circuit 11Q. In the present embodiment, the number of the heart mode selection signals is N', and the number of drive current setting values is M. In the present embodiment, (4) material 13G_Electrical pattern 睹Amm ~ μ " main form number A0101 page 7 / 19 pages [0018] M392419 2 to 4, the voltage dividing circuit 130 includes first to the first Three resistors R1, R2 and R3. The first resistor R1 and the second resistor R2 are sequentially connected in series between the output terminal of the boosting power conversion circuit 100 and the ground, and the feedback voltage Vp is the voltage of R2 on the second resistor. The third resistor R3 receives the regulated voltage Vo, and one end is connected between the first resistor R1 and the second resistor R2. In other embodiments of the present invention, the voltage dividing circuit 130 can also be implemented using a capacitor or a diode or the like. 2 is a specific circuit diagram of the LED backlight driving system 10 of the first embodiment of the present invention. In the present embodiment, the compensation voltage generating circuit 140 includes a first switching element Q1, a second switching element Q2, a fourth resistor R4, and a fifth resistor R5. The first switching element Q1 and the second switching element Q2 respectively include a control end, an input end and an output end, and the control end respectively receives the first mode selection signal and the second mode selection signal, the input end is grounded, and the output ends are respectively connected One end of the fourth resistor R4 and one end of the fifth resistor R5. The fourth resistor R4 and the other end of the fifth resistor R5 are connected to each other and are commonly connected between the first resistor R1 and the second resistor R2 of the voltage dividing circuit 130. In this embodiment, the first switching element Q1 and the second switching element Q2 are both N-type metal oxide semiconductor field effect transistors, the control terminals are gates, and the input terminals are all sources, and the output ends are all Bungee jumping. The resistance of the fourth resistor R4 and the fifth resistor R5 are different. [0020] controlling the on and off of the first switching element Q1 and the second switching element Q2 by inputting the first mode selection signal and the second mode selection signal to the first switching element Q1 and the second switching element Q2, thereby switching the voltage division The parallel resistance of the second resistor R2 of the circuit 130 changes the feedback voltage Vp. [0021] The first mode selection signal and the second mode selection signal are logic high and low level signals, for example, the logic high level signal is 5V, and the logic low level signal is form number A0101 page 8 / total 19 pages M392419 ον. If at least one of the first mode selection signal and the second mode selection signal is a logic high level signal, at least one of the first switching element Q1 and the second switching element Q2 is turned on, and thus the fourth resistor R4 and the fifth resistor R5 are at least one In parallel with the second resistor R2, the divided voltage on the first resistor R1 becomes large, so that the feedback voltage Vp is small. If the first mode selection signal and the second mode selection signal are both logic low signals, the first switching element Q1 and the second switching element Q2 are both turned off, and no resistance is connected in parallel with the second resistor R2, and the voltage Vp is fed back at this time. Larger. In this way, according to different driving current requirements, the corresponding mode selection signal is input, and the feedback voltage Vp is changed, thereby correspondingly changing the set point of the output voltage Vout of the boosting power conversion circuit 100, and the multi-channel constant current driving circuit 110 is lowered. Adjust the adjustment range of voltage Vo. [0022] In FIG. 2, the number of the light emitting diode arrays 20 is one, and the compensation voltage generating circuit 140 in the first embodiment is easy to implement, and the circuit is simple. [0023] FIG. 3 shows the second in the present invention. A specific circuit diagram of the LED backlight driving system 10 in the embodiment. In the present embodiment, the LED backlight source driving system 10 is used to drive a plurality of LED arrays 20, 21, of which only two are shown in FIG. The LED array 20 corresponds to the boosting power conversion circuit 100, the multi-channel constant current driving circuit 110, the controller 120, and the voltage dividing circuit 130. The LED array 21 corresponds to the boosting power conversion circuit 101 and the multi-channel constant current. The driving circuit 111, the controller 121, and the voltage dividing circuit 131, and the circuit structure and the connection relationship are the same as those in FIG. 2, and details are not described herein again. The LED backlight driving system 10 includes a compensation voltage generating circuit 140', and the compensation voltage generating circuit 140' includes a form number A0101, page 9 / 19 pages, M392419, a second switching element Q3, a fourth switching element Q4, and a sixth resistor. R6 and seventh resistor R7, eighth resistor R8, ninth resistor R9 and voltage follower 1400. The connection relationship between the second switching element Q3, the fourth switching element Q4, the sixth resistor R6, and the seventh resistor R7 is the same as that of the compensation voltage generating circuit 14A in FIG. 2, and details are not described herein again. The eighth resistor R8 and the ninth resistor R9 are connected in series between the reference voltage Vcc and the ground and the common node is connected to the other end of the sixth resistor R6 and the seventh resistor R7. The forward input of the voltage follower 14A is connected between the eighth resistor R8 and the ninth resistor R9, and the output terminal is connected to the first resistor R1 of each of the component voltage circuits 130, 131 via the tenth resistor R10. Between the second resistor R2 and the second resistor R2, the compensation voltage v〇ffset is output. The voltage follower 1400 is used to stabilize its compensation voltage voffse1: such that its compensation voltage Voffset does not change due to load. [0024] In this embodiment, by inputting the first mode selection signal and the second mode selection signal, controlling the on and off of the third switch Q3 and the fourth switch Q4 to change the parallel resistance with the ninth resistor R9, thereby changing The voltage division of the ninth resistor R9 changes the compensation voltage Voffset output by the voltage follower 14 〇〇. Thus, by changing the compensation voltage v〇ffset, the feedback voltage Vp of the voltage dividing circuit 130 is changed, thereby changing the set point of the output voltage Vout of the boosting power conversion circuit 100, and the regulated voltage of the multi-channel constant current driving circuit 110 is lowered. Vo's adjustment range. The compensating voltage generating circuit 140' in the present embodiment can stabilize the compensating voltage v 〇 ffset and is suitable for the case where there are a plurality of illuminating diode arrays 2 。. 4 is a specific circuit diagram of the LED backlight driving system 10 according to the third embodiment of the present invention. In the present embodiment, the LED backlight driving system 10 is different from that of FIG. 2 in that The compensation voltage generation circuit is implemented by the form number A0101, page 10/19, M392419 microprocessor 140''. The microprocessor 140'' receives the first mode selection signal and the second mode selection signal, correspondingly generates a compensation voltage Voffset and superimposes the compensation voltage Voffset on the second resistor R2 through the eleventh resistor R11. The compensation voltage generating circuit 140'' in the present embodiment is applied to the design of a single wafer at the time of design. The illuminating diode backlight driving system 10 uses the compensation voltage generating circuit 140 to generate a suitable compensation voltage Voffset to change the feedback voltage Vp of the voltage dividing circuit 130 to change the output voltage Vout of the boosting power conversion circuit 100. The set point is such that the adjustment range of the adjustment voltage Vo of the multi-channel constant current driving circuit 110 is reduced, the adjustment precision is increased, the optimal value can be truly adjusted to achieve efficiency optimization, and the multi-channel constant current driving can be reduced. The temperature of circuit 110. [0027] In summary, the present invention complies with the new patent requirements and submits a patent application according to law. However, the above-mentioned ones are only preferred embodiments of the present invention, and equivalent modifications or variations made by those skilled in the art to the present invention should be included in the following claims. BRIEF DESCRIPTION OF THE DRAWINGS [0028] FIG. 1 is a schematic diagram of a backlight driving system for a light-emitting diode according to an embodiment of the present invention, and FIG. 2 is a backlight driving of a light-emitting diode according to a first embodiment of the present invention; [0030] FIG. 3 is a circuit diagram of a backlight driving system for a light emitting diode according to a second embodiment of the present invention; and FIG. 4 is a backlight driving system for a light emitting diode according to a third embodiment of the present invention; Circuit diagram of Form No. A0101, page 11 of 19, M392419. [Main component symbol description] [0032] LED backlight drive system: 10 [0033] Boost power conversion circuit: 1 0 0, 1 0 1 [0034] Multi-channel constant current drive circuit: 110, 111 [0035 ] Controller: 120, 121 [0036] Voltage dividing circuit: 130, 131 [0037] Compensation voltage generating circuit: 140, 140' [0038] Microprocessor: 140' ' [0039] LED array: 20 21 [0040] LED string: 200, 210 [0041] DC power signal: Vi η [0042] Output voltage: Vout [0043] Feedback voltage: Vp [0044] Regulation voltage: Vo [0045] Reference voltage :Vcc [0046] Compensation voltage: Vof fset [0047] First to eleventh resistors: R1 to R11 [0048] First to fourth switches: Q1 to Q4 Form No. A0101 Page 12 of 19