200945292 .九、發明說明： .【發明所屬之技術領域】 本發明係關於一種背光驅動電路、應用該背光驅動電路 之顯示裝置及該背光驅動電路之驅動方法。 【先前技術】 液晶顯示裝置因具有低輻射性、體積小及耗電低等特 點，且隨著相關技術之成熟及創新，而被廣泛應用於行動電 話、個人數位助理、便攜式數位視訊光碟播放器（Digital Video Disc，DVD)、筆記型電腦及電視等領域。然而，由於 液晶顯不面板本身不具發光特性，所以通常須配合一背光模 組才能達至顯示效果。背光模組通常包括一背光驅動電路。 請參閱圖1 ’係一先前技術背光驅動電路之電路結構示 忍圖。該背光驅動電路1包括一電源電路η、一怪流電路12、 一控制器13、一光源14及一系統邏輯電路15。該電源電路u 包括二輸出端，其一輸出端為該系統邏輯電路15提供一邏輯 ❹電壓，其另一輸出端供給該恆流電路12一直流電壓。該控制 器13根據背光驅動電路1之工作模式產生占空比不同但頻率 恆定之脈衝訊號。該恆流電路12接收該脈衝訊號，並且根據 該脈衝訊號之占空比產生一恆定電流以驅動該光源14。該光 源係一發光二極體。 惟，在省電模式下，該恆流電路12根據該脈衝訊號之占 空比將該電源電路11提供之電能轉化為一恆定電流驅動該 光源14。由於該恆流電路12之電路組件動作而引起之電能損 耗，使該電源電路11提供之電能未能完全用於驅動該光源14 發光，因而，該背光驅動電路i之電能利用率較低。 6 200945292 ,【發明内容】 • _於此，提供一㈣能利用效率較高之背光驅動電路 實為必要。 有鑑於此，提供一種應用上述背光驅動電路之顯示裝置 亦為必要。 有鑑於此’提供—種電能利用效率較高之f光驅動電路 驅動方法亦為必要。 ❹ 種淥光軀動電路，其包括—驅動模塊、一電源電路及 一控制器。該驅動模塊驅動一光源。該電源電路提供一電源 至該驅動模塊。該控制器連接到該驅動模塊，在正常工作模 式下，該控制器使該驅動模塊產生並輸出一恆定電流驅動該 光源；在省電模式下，該控制器使該電源直接驅動該光源。 一種顯不裝置，其包括一顯示面板及一背光模組。該背 光模組包括一背光驅動電路。該背光驅動電路包括一驅動模 塊、一電源電路及一控制器。該驅動模塊驅動一光源。該電 ©源電路提供一電源至該驅動模塊。該控制器連接到該驅動模 塊，在正常工作模式下，該控制器使該驅動模塊產生並輸出 一恆定電流驅動該光源，·在省電模式下，該控制器使該電源 直接驅動該光源。 一種为光驅動電路驅動方法，其包括以下步驟··提供一 控制器，其根據該背光驅動電路之工作模式發出控制訊號； 提供一驅動模塊，其接收該控制器發出之控制訊號，並根據 該控制訊號，使該驅動模塊在正常工作模式下，輸出一恆定 電流驅動該光源；在省電模式下，使該電源電路直接驅動該 7 200945292 . 光源。 .. 相較於㈣技術，本發明之背光驅動電路，在正常工作 模式下’該驅賴塊㈣電㈣路提供之電能轉化成一 電流以驅動該光源。在省電模式下，由該電源電路直接驅動 該光源，而無須進行電能之轉化，減少電能轉化過程之電能 =耗。提高了該背光驅動電路之電能則效率。應用本發明 考先驅動電路之顯示裝置亦提高其電能利用率。本發明之 ❿光驅動電路驅動方法亦提高該背光驅動電路之電能利。 【實施方式】 請參閱圖2，係本發明背光驅動電路第-實施方式之電 路結構示意圖。該背光驅動電路2包括一驅動模塊加 源電路21、-控制器23、一光源25及一系統邏輯電路％。 其中，該驅動模塊20包括一怪流電路22及一開關電路2心 該光源25係一發光二極體。 名電源電路21包括一第一電源輸出端211及一第二電 輸出端212。該第-電源輸出端211為該系統邏輯電路26 提供邏輯電壓。該第二電源輸出端212為該怪流電路Μ 提供一直流電壓。 該開關電路24包括-第一電源輸入端241、一第二電源 輸^端242帛關控制端244及一輸出端243。該輸出243 4藉由該光源25接地。該第—電源輸人端241直接與該電 源電路21之第一電源輸出端211電連接。 山該怪流電路22包括一電源輸入端221、一怪定電流輪出 端223及一控制端222。該電源輸入端221與該電源電路2工 200945292 /之第二電源輸出端212電連接。該怪定電流輸出端223電連 .接該開關電路24之第二電源輸入端242。 該控制$ 23包括二控制輸出端231，其分別與該恆流電 路22之控制端222及該開關電路24之開關控制端244電連 接。 該背光驅動電路2卫作時，該控制器23根據該背光驅 電路2之工作模式控制該怪流電路22及該開關電路^。 〇在正常工作模式下，該控制器23輸出一第一控制訊號使該 7關電路24之輸出端243與該開關電路％之第二電源輸入 端242相互電連接。該控制器23同時輸出一頻率高於丄週z ，脈衝訊號至m電路22。該㈣電路22根據該脈衝訊 號之占二比產生一恆定電流以驅動該光源25。在省電模式 下該控制器23輸出一第二控制訊號使該開關電路之輸 出端243與該開關電路24之第一電源輸入端241相互電連 接。該光源25直接由該電源電路21驅動。 ❹ 相較先前技術，因本發明之背光驅動電路2具有開關電 路24，在正常工作模式下，由該恆流電路22產生一恆定電 流驅動該光源25;在省電模式下，由該電源電路2直接驅動 該光源25,而該怪流電路22無負载，減少該怪流電路22 之電能損耗。提高了該背光驅動電路2之電能利用效率。 請參閱圖3，係本發明背光驅動電路第二實施方式之電 路結構示意圖。該背光驅動電路3包括一驅動模塊3〇、一電 源電路、一控制器33、一光源35及一系統邏輯電路％。 其中，该驅動模塊30包括一恆流電路32及一開關電路％。 9 200945292 該光源35係一發光二極體。 該電源電路31包括-第—電源輸出端311及—第二電 源輪出端312。該第一雷调拾山。n上 提供-邏輯電壓。 知311為該系統邏輯電路36 該開關電路34包括一第一電源輸入端341、一第二電源 輸入端342、一開關控制端344、一第一輸出端343及一第 ❹ -輸出端345。該第二電源輸入端342與該電源電路μ之第 二電源輸出端312電連接。兮笛 恭、Ε 士人 ㈣μ ^ 电祕該第一電源輸入端341與該電源 電路31之第一電源輸出端311 藉由該光源35接地。 電連接。該第一輸出端343 該怪流電路32包括-電源輸入端321、一控制端奶 及一怪定電流輸出端323。該電 通！源輸入鈿321與該開關電路 34之第二輪出端345電連接。該怪定電流輸出端％ 該光源35接地。 # 該控制H 33包括二控職_ 331，其分難該怪流電 ❹路32之控制端322及該開關電路34之開關控制端糾電連 接0 該背総動電路3工作時，該控㈣33根據該背光驅 動電路3之工作模式控制該怪流電路％及該開關電路μ。 在正常工作模式下，該控制器33輸出一第一控制訊號使該 開關電路34之第二輸出端345與該開關電路34之第二 輸入端312相互電連接，並使該開關電路別之第 343與該開關電路34之第一電源輸入端341斷開。該控制器 33同時輸出-頻率高於15KHz之脈衝訊號至該怪流電路 200945292 32。雜流電路32根據該脈衝訊號之占空比產生一值定電 流驅動該光源35。在省電模式下，該控制器％輸出一第二 控制，使該開關電路34之第一輸出端343與該開關電路 哲之第一電源輸入端341相互電連接’並使該開關電路34 之第二輸出端345與該開關雷致夕贫 兴忒開關電路34之第二電源輸入端342 ”該光源35直接由該電源電路31之第一電源輸出端3ιι ❹ 〇 相較於該第一實施方式之背光驅動電路2，該第二實施 2之背光驅動電路3之開關電路34在省電模式下將該電 路31與該恆流電路32之連接斷開。使該怪流電路％ 不產生電能損耗。進-步提高了該背光驅動電路 用效率。 in·] 請參閱圖4,係本發明背光驅動電路第三實施方式之電 路結構示意圖。該背光驅動電路4包括—驅動模塊4〇、一電 ，電路41、—控制器43、—光源45及-系統邏輯電路46。 其中’該㈣模塊40包括一怪流電路42、一檢測器〜及― 開關電路44。該光源45係一發光二極體。 «亥電源電路41包括一第一電源輸出端411及一第二電 原輸出端412該第一電源輸出端411為該系統邏輯電路邾 提供電源。 該開關電路44包括一第一電源輸入端441、一第二電源 輸入*端442 關控制端444及—輸出端443。該輸出端 443藉由該光源45接地。該第一電源輸入端441與該電源電 路41之第一電源輸出端411電連接。 11 200945292 . 該恆流電路42包括一電源輸入端421、一控制端422 .及一恆定電流輸出端423。該恆定電流輸出端423與該開關 電路44之第二電源輸入端442電連接。該電源輸入端々a 與該電源電路41之第二電源輸出端412電連接。 該檢測器47包括-信號輸人端471及二控制輸出端 472。該二控制輸出端472分別與該恆流電路“之控制端422 及該開關電路44之開關控制端444電連接。 ❹ 該控制器43包括一訊號輸出端431，其與該檢測器47 之訊號輸入端電471連接。 該背光驅動電路4卫作時，該控制器43根據該背光驅 動電路4之工作模式輸出一頻率高於15KHz而占空比隨工 作模式變化而變化之脈衝訊號。在正常工作模式下，該脈衝 信號之占控比要比在省電模式下之占空比要大。該檢測器Ο 接收該脈衝訊號’並根據該脈衝訊號之占空比判斷該背光驅 動電路4之工作模式’簡時生成控觀號控制雜流電路 ❹42及該開關電路44。在正常工作模式下，該檢測器47輸出 一第一控制訊號使該開關電路44之第二電源輸入端梢與 該開關電路44之輸出端443相互電連接。該檢測器47同時 將所接收之脈衝訊號輸出至該恒流電路42。該怪流電路42 接收該脈衝訊號並根據該脈衝訊號產生—怪定電流驅動該 光源45。在省電模式下，該檢測器们輪出—第二控制訊號 至该開關電路44使該開關電路44之第一電源輸入端441與 該開關電路44之輸出端443相互電連接。該光源衫由該電 源電路41直接驅動。 12 200945292 . 相較於該第一實施方式之背光驅動電路2,該第三實施 .方式之背光驅動電路4具有一檢測器47。該檢測器47接收 該控制器之脈衝訊號並控制該恆流電路42及該開關電路 44 ’減少该背光驅動電路4在先前技術背光驅動電路工基礎 之電路改變量。 請參閱圖5 ’係本發明背光驅動電路第四實施方式之電 路結構示意圖。該背光驅動電路5與該背光驅動電路4基本 ❾相同，其區別在於：開關電路54包括複數輸出端。光源 55包括複數發光二極體。每一輸出端543藉由一發光二極體 接地。該背光驅動電路5工作時，該開關電路54根據檢測 器53發出之控制訊號使該複數發光二極體由怪流電路μ產 生之恆定電流驅動或直接由電源電路51驅動，並可使部份 發光二極體工作。 請參閱圖6,係本發明一背光驅動電路驅動方法流程 ®本彦光驅動電路驅動方法適用於上述任一實施方式之背 〇光驅動電路。下面以驅動該背光驅動電路2為例說明該背光 驅動電路之驅動方法。 該背光驅動電路驅動方法包括以下步驟： 步驟S1 :提供—控制器^，其根據該背光驅動電路2 之工作模式發出控制訊號； 該控制H 23監測該背光驅動電路2，並根據該背光驅動 電路2之不同工作模式向該怪流電路22及該開關電路 ，訊號。在正常工作模式下，該控制器23向該開“ 24輸出一第一控制訊號，並向該恆流電路22輸出一頻率 13 200945292 ，高於15KHz之脈衝訊號；在省電模式下，該控制器23向該 開關電路24輸出一第二控制訊號。 步驟S2 :提供一驅動模塊2〇 ’其接收該控制器23之控 制訊號，並根據該控制訊號驅動該光源25。在正常工作模式 下，該驅動模塊2輸出一恆定電流驅動該光源25 ;在省電模 式下，使該電源電路21直接驅動該光源25。 該驅動模塊20包括該恆流電路22及該開關電路24。在 ❿正常工作模式下，該開關電路22接收該第一控制訊號，並 使該開關電路24之第二電源輸入端242與該開關電路24之 輸出端243相互電連接；同時，該恆流電路22接收該脈衝 訊號，並根據該脈衝訊號之占空比產生一恆定電流驅動該光 源25。在省電模式下，該開關電路22接收該第二控制訊號， 並使該開關電路24之第一電源輸入端241與該開關電路24 之輸出端243相互電連接；該光源25直接由該電源電路21 驅動。 〇 惟，本發明並不限於上述實施方式所述，如該開關電路 24亦可包括更多電源輸入端’該電源電路21亦可以包括更 多電源輸出端，該開關電路24之複數輸入端分別與該電源 電路21之複數電源輸出端電連接；該恆流電路42包括由一 驅動積體電路晶片及複數電子組件連接而成，該開關電路44 及'•亥檢測器47亦可集成於該怪流電路42之驅動積體電路晶 片中，該脈衝訊號亦可係一頻率隨機連續變化之脈衝訊號且 其頻率亦可低於15KHz;本發明還提供一種顯示裝置，其包 括顯示面板及一應用上述背光驅動電路之背光模組，其中 200945292 .該顯示面板係一液晶顯示面板或一電濕潤顯示面板。 . 綜上所述，本發明確已符合發明專利之要件，爰依法提 出專利申請。惟，以上所述者僅為本發明之較佳實施方式， 本發明之範圍並不以上述實施方式為限，舉凡熟悉本案技藝 之人士援依本發明之精神所作之等效修飾或變化，皆應涵蓋 於以下申請專利範圍内。 【圖式簡單說明】 ❹圖1係一先前技術背光驅動電路之電路結構示意圖。 圖2係本發明背光驅動電路第一實施方式之電路結構示意 圖。 、 圖3係本發明背光驅動電路第二實施方式之電路結構示音 圖。 w 圖4係本發明背光驅動電路第三實施方式之電路結構示惫 圓。 。 圖5係本發明背光驅動電路第四實施方式之電路結構示意 圖6係圖2所示背光驅動電路之驅動方法流程圖。 【主要元件符號說明】 檢測器 者光驅動電路 電源電路 驅動模塊 恆流電路 開關電路 47 2、3、4、5 21 、 31 、 41 、 51 2〇、30、40 22、32、42、52 24、34、44、54 15 200945292 Ο 控制器 系統邏輯電路 光源 第一電源輸出端 弟-電源輸出端 第一電源輸入端 第二電源輸入端 輸出端 開關控制端 電源輸入端 恆定電流輸出端 控制端 控制輸出端 第一輸出端 第二輸出端 訊號輸出端 訊號輸入端 23 、 33 ' 43 、 53 26 、 36 、 46 25、35 ' 45、55 211 、 311 、 411 212、312、412 241 、 341 、 441 242、342、442 243 、 443 、 543 244、344、444 221 、 321 、 421 223 、 323 、 423 222 ' 322 ' 422 231 、 331 、 472 343 345 431 471 16200945292. IX. Description of the Invention: The present invention relates to a backlight driving circuit, a display device using the same, and a driving method of the backlight driving circuit. [Prior Art] Liquid crystal display devices are widely used in mobile phones, personal digital assistants, and portable digital video disc players due to their low radiation, small size, low power consumption, and the maturity and innovation of related technologies. (Digital Video Disc, DVD), notebook computers and TV. However, since the liquid crystal display panel itself does not have a light-emitting property, it is usually necessary to match a backlight module to achieve a display effect. The backlight module usually includes a backlight driving circuit. Please refer to FIG. 1 for a circuit diagram of a prior art backlight driving circuit. The backlight driving circuit 1 includes a power circuit η, a strange circuit 12, a controller 13, a light source 14, and a system logic circuit 15. The power supply circuit u includes two output terminals, one output terminal of which provides a logic voltage to the system logic circuit 15, and the other output terminal supplies the constant current circuit 12 to the current voltage. The controller 13 generates pulse signals having different duty ratios but constant frequencies in accordance with the operation mode of the backlight driving circuit 1. The constant current circuit 12 receives the pulse signal and generates a constant current according to the duty ratio of the pulse signal to drive the light source 14. The light source is a light emitting diode. However, in the power saving mode, the constant current circuit 12 converts the power provided by the power circuit 11 into a constant current to drive the light source 14 according to the duty ratio of the pulse signal. Due to the power loss caused by the operation of the circuit component of the constant current circuit 12, the power provided by the power supply circuit 11 is not fully used to drive the light source 14 to emit light, and thus the power utilization of the backlight driving circuit i is low. 6 200945292, [Inventive content] • _In this case, it is necessary to provide one (four) backlight driving circuit that can utilize high efficiency. In view of the above, it is also necessary to provide a display device to which the above backlight driving circuit is applied. In view of the above, it is also necessary to provide a method of driving an optical drive circuit with high power utilization efficiency. A fluorescent body circuit includes a driving module, a power circuit, and a controller. The drive module drives a light source. The power circuit provides a power supply to the drive module. The controller is coupled to the drive module, which in the normal mode of operation causes the drive module to generate and output a constant current to drive the light source; in the power save mode, the controller causes the power source to directly drive the light source. A display device includes a display panel and a backlight module. The backlight module includes a backlight driving circuit. The backlight driving circuit includes a driving module, a power supply circuit and a controller. The drive module drives a light source. The power source circuit provides a power supply to the driver module. The controller is coupled to the drive module which, in the normal mode of operation, causes the drive module to generate and output a constant current to drive the light source. In the power save mode, the controller causes the power source to directly drive the light source. A driving method for an optical driving circuit, comprising the steps of: providing a controller for issuing a control signal according to an operation mode of the backlight driving circuit; providing a driving module, receiving a control signal sent by the controller, and according to the The control signal is such that the driving module outputs a constant current to drive the light source in a normal working mode; in the power saving mode, the power circuit directly drives the light source. Compared with the (4) technique, the backlight driving circuit of the present invention converts the electric energy supplied by the (four) electric (four) circuit into a current to drive the light source in the normal operation mode. In the power saving mode, the light source is directly driven by the power supply circuit, and no conversion of electric energy is required, thereby reducing the electric energy consumption of the electric energy conversion process. The efficiency of the power of the backlight driving circuit is improved. The display device using the driving circuit of the present invention also improves the power utilization rate. The driving method of the neon driving circuit of the present invention also improves the power of the backlight driving circuit. [Embodiment] Please refer to Fig. 2, which is a schematic diagram of a circuit structure of a backlight drive circuit according to a first embodiment of the present invention. The backlight driving circuit 2 includes a driving module adding circuit 21, a controller 23, a light source 25, and a system logic circuit %. The driving module 20 includes a strange circuit 22 and a switching circuit 2, and the light source 25 is a light emitting diode. The power supply circuit 21 includes a first power output 211 and a second electrical output 212. The first power supply output 211 provides a logic voltage to the system logic circuit 26. The second power output terminal 212 provides a DC voltage to the strange current circuit Μ. The switch circuit 24 includes a first power input terminal 241, a second power supply terminal 242, a control terminal 244, and an output terminal 243. The output 243 4 is grounded by the light source 25. The first power input terminal 241 is directly electrically connected to the first power output terminal 211 of the power circuit 21. The circuit 24 includes a power input terminal 221, a strange current wheel output terminal 223, and a control terminal 222. The power input terminal 221 is electrically connected to the power supply circuit 2 200945292 / the second power output terminal 212. The strange current output terminal 223 is electrically connected to the second power input terminal 242 of the switch circuit 24. The control $23 includes two control outputs 231 that are electrically coupled to the control terminal 222 of the constant current circuit 22 and the switch control terminal 244 of the switch circuit 24, respectively. When the backlight driving circuit 2 is in operation, the controller 23 controls the strange current circuit 22 and the switching circuit according to the operating mode of the backlight driving circuit 2. In the normal operation mode, the controller 23 outputs a first control signal to electrically connect the output terminal 243 of the 7-circuit circuit 24 to the second power input terminal 242 of the switch circuit %. The controller 23 simultaneously outputs a frequency higher than the z z, pulse signal to the m circuit 22. The (four) circuit 22 generates a constant current based on the ratio of the pulse signals to drive the light source 25. In the power saving mode, the controller 23 outputs a second control signal to electrically connect the output terminal 243 of the switch circuit to the first power input terminal 241 of the switch circuit 24. The light source 25 is directly driven by the power supply circuit 21.背光 Compared with the prior art, the backlight driving circuit 2 of the present invention has a switching circuit 24, in which a constant current is generated by the constant current circuit 22 to drive the light source 25; in the power saving mode, the power supply circuit 2 directly driving the light source 25, and the strange flow circuit 22 has no load, reducing the power loss of the strange flow circuit 22. The power utilization efficiency of the backlight driving circuit 2 is improved. Please refer to FIG. 3, which is a schematic diagram of the circuit structure of the second embodiment of the backlight driving circuit of the present invention. The backlight driving circuit 3 includes a driving module 3, a power circuit, a controller 33, a light source 35, and a system logic circuit %. The driving module 30 includes a constant current circuit 32 and a switching circuit %. 9 200945292 The light source 35 is a light-emitting diode. The power supply circuit 31 includes a -first power supply output 311 and a second power supply output 312. The first thunder picked up the mountain. Provide a - logic voltage on n. The switch circuit 34 includes a first power input terminal 341, a second power input terminal 342, a switch control terminal 344, a first output terminal 343, and a first output terminal 345. The second power input 342 is electrically coupled to the second power output 312 of the power circuit μ.兮 恭, 士士士人 (4) μ ^ The first power input terminal 341 and the first power output terminal 311 of the power circuit 31 are grounded by the light source 35. Electrical connection. The first output terminal 343 includes a power input terminal 321, a control terminal milk, and a strange current output terminal 323. The power! The source input port 321 is electrically coupled to the second wheel terminal 345 of the switch circuit 34. The strange current output terminal % is grounded. # The control H 33 includes two control positions _ 331, which is difficult to blame the control terminal 322 of the turbulent circuit 32 and the switch control terminal of the switch circuit 34 to correct the electrical connection 0 when the back sway circuit 3 is in operation, the control (4) 33 controls the strange current circuit % and the switch circuit μ according to the operation mode of the backlight driving circuit 3. In the normal operation mode, the controller 33 outputs a first control signal to electrically connect the second output terminal 345 of the switch circuit 34 and the second input terminal 312 of the switch circuit 34, and make the switch circuit different. 343 is disconnected from the first power input 341 of the switch circuit 34. The controller 33 simultaneously outputs a pulse signal having a frequency higher than 15 kHz to the strange current circuit 200945292 32. The snubber circuit 32 generates a constant current to drive the light source 35 according to the duty ratio of the pulse signal. In the power saving mode, the controller % outputs a second control such that the first output terminal 343 of the switch circuit 34 and the first power input terminal 341 of the switch circuit are electrically connected to each other 'and the switch circuit 34 The second output end 345 and the second power input end 342 of the switch thundering switch circuit 34 are directly connected to the first power output terminal 3 of the power circuit 31 compared to the first embodiment. The backlight driving circuit 2, the switching circuit 34 of the backlight driving circuit 3 of the second embodiment 2 disconnects the circuit 31 from the constant current circuit 32 in the power saving mode, so that the strange current circuit % does not generate power loss. The step-by-step method improves the efficiency of the backlight driving circuit. In·] Please refer to FIG. 4, which is a schematic diagram of the circuit structure of the third embodiment of the backlight driving circuit of the present invention. The backlight driving circuit 4 includes a driving module 4〇, an electric The circuit 41, the controller 43, the light source 45, and the system logic circuit 46. The 'fourth module 40 includes a strange flow circuit 42, a detector ~ and a switch circuit 44. The light source 45 is a light emitting diode Body. «Haidian The circuit 41 includes a first power output 411 and a second power output 412. The first power output 411 provides power to the system logic circuit 。. The switch circuit 44 includes a first power input 441, a first The second power input terminal 442 is connected to the control terminal 444 and the output terminal 443. The output terminal 443 is grounded by the light source 45. The first power input terminal 441 is electrically connected to the first power output terminal 411 of the power supply circuit 41. The constant current circuit 42 includes a power input terminal 421, a control terminal 422, and a constant current output terminal 423. The constant current output terminal 423 is electrically connected to the second power input terminal 442 of the switch circuit 44. The input terminal 々a is electrically connected to the second power output terminal 412 of the power circuit 41. The detector 47 includes a signal input terminal 471 and two control outputs 472. The two control outputs 472 and the constant current circuit respectively The control terminal 422 and the switch control terminal 444 of the switch circuit 44 are electrically connected. The controller 43 includes a signal output terminal 431 that is coupled to the signal input terminal 471 of the detector 47. When the backlight driving circuit 4 is operated, the controller 43 outputs a pulse signal whose frequency is higher than 15 kHz and whose duty ratio changes with the change of the operating mode according to the operation mode of the backlight driving circuit 4. In the normal operating mode, the duty ratio of the pulse signal is greater than the duty cycle in the power saving mode. The detector Ο receives the pulse signal ′ and determines the operating mode of the backlight driving circuit 4 according to the duty ratio of the pulse signal, and generates the control number control circuit ❹ 42 and the switching circuit 44. In the normal mode of operation, the detector 47 outputs a first control signal to electrically connect the second power input terminal of the switch circuit 44 to the output 443 of the switch circuit 44. The detector 47 simultaneously outputs the received pulse signal to the constant current circuit 42. The strange current circuit 42 receives the pulse signal and generates the light source 45 according to the pulse signal. In the power saving mode, the detectors rotate the second control signal to the switch circuit 44 to electrically connect the first power input 441 of the switch circuit 44 to the output 443 of the switch circuit 44. The light source shirt is directly driven by the power source circuit 41. 12 200945292. The backlight driving circuit 4 of the third embodiment has a detector 47 as compared with the backlight driving circuit 2 of the first embodiment. The detector 47 receives the pulse signal of the controller and controls the constant current circuit 42 and the switch circuit 44' to reduce the amount of circuit change of the backlight drive circuit 4 based on the prior art backlight drive circuit. Please refer to FIG. 5, which is a schematic diagram of a circuit structure of a fourth embodiment of the backlight driving circuit of the present invention. The backlight driving circuit 5 is substantially the same as the backlight driving circuit 4, except that the switching circuit 54 includes a plurality of output terminals. Light source 55 includes a plurality of light emitting diodes. Each output 543 is grounded by a light emitting diode. When the backlight driving circuit 5 is in operation, the switching circuit 54 drives the complex LED to be driven by the constant current generated by the strange circuit μ or directly by the power circuit 51 according to the control signal sent from the detector 53. The light emitting diode works. Referring to FIG. 6, a method for driving a backlight driving circuit of the present invention is to be applied to the backlight driving circuit of any of the above embodiments. The driving method of the backlight driving circuit will be described below by taking the backlight driving circuit 2 as an example. The backlight driving circuit driving method includes the following steps: Step S1: providing a controller, which outputs a control signal according to an operation mode of the backlight driving circuit 2; the control H23 monitors the backlight driving circuit 2, and according to the backlight driving circuit 2 different working modes to the strange flow circuit 22 and the switch circuit, the signal. In the normal operation mode, the controller 23 outputs a first control signal to the opening 24, and outputs a frequency 13 200945292 to the constant current circuit 22, which is higher than the 15KHz pulse signal; in the power saving mode, the control The controller 23 outputs a second control signal to the switch circuit 24. Step S2: providing a driving module 2' to receive the control signal of the controller 23, and driving the light source 25 according to the control signal. In the normal working mode, The driving module 2 outputs a constant current to drive the light source 25. In the power saving mode, the power circuit 21 directly drives the light source 25. The driving module 20 includes the constant current circuit 22 and the switching circuit 24. In the mode, the switch circuit 22 receives the first control signal, and electrically connects the second power input terminal 242 of the switch circuit 24 and the output terminal 243 of the switch circuit 24; meanwhile, the constant current circuit 22 receives the pulse. a signal, and generating a constant current according to the duty ratio of the pulse signal to drive the light source 25. In the power saving mode, the switch circuit 22 receives the second control signal, and causes the switch circuit The first power input terminal 241 of 24 and the output terminal 243 of the switch circuit 24 are electrically connected to each other; the light source 25 is directly driven by the power supply circuit 21. However, the present invention is not limited to the above embodiment, such as the switch circuit 24 may also include more power input terminals. The power circuit 21 may also include more power output terminals. The plurality of input terminals of the switch circuit 24 are respectively electrically connected to the plurality of power output terminals of the power circuit 21; the constant current circuit 42 The circuit includes a driver integrated circuit chip and a plurality of electronic components. The switch circuit 44 and the 'detector 47 can also be integrated into the driving integrated circuit chip of the strange current circuit 42. The pulse signal can also be The present invention further provides a display device comprising a display panel and a backlight module using the backlight driving circuit, wherein the display panel is a liquid crystal. Display panel or an electrowetting display panel. In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. The present invention is only a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and equivalent modifications or variations made by those skilled in the art in light of the spirit of the present invention should be BRIEF DESCRIPTION OF THE DRAWINGS The following is a schematic diagram of the circuit structure of a prior art backlight driving circuit. Fig. 2 is a schematic view showing the circuit structure of the first embodiment of the backlight driving circuit of the present invention. The circuit structure of the second embodiment of the backlight driving circuit is shown in Fig. 4. The circuit structure of the third embodiment of the backlight driving circuit of the present invention is shown in Fig. 4. Fig. 5 is a circuit structure of a fourth embodiment of the backlight driving circuit of the present invention. FIG. 6 is a flow chart showing a driving method of the backlight driving circuit shown in FIG. 2. [Main component symbol description] Detector optical drive circuit power supply circuit drive module constant current circuit switch circuit 47 2, 3, 4, 5 21 , 31 , 41 , 51 2〇, 30, 40 22, 32, 42, 52 24 , 34, 44, 54 15 200945292 Ο controller system logic circuit light source first power output terminal brother - power output terminal first power input terminal second power input terminal output terminal switch control terminal power input terminal constant current output terminal control terminal control Output first output terminal second output terminal signal output terminal signal input terminal 23, 33 '43, 53 26 , 36 , 46 25 , 35 ' 45 , 55 211 , 311 , 411 212 , 312 , 412 241 , 341 , 441 242, 342, 442 243, 443, 543 244, 344, 444 221, 321 , 421 223 , 323 , 423 222 ' 322 ' 422 231 , 331 , 472 343 345 431 471 16