201215227 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種控制器，特別是—種光源調光控制 器0 【先前技術】 脈衝調光週期可用於控制光源（例如，發光二極體）的 亮度。-個脈衝調光週期包括導通階段和關閉階段。在導 通階段有多個電流脈衝流過光源，在關閉階段則沒有電流 流過光源。因此，透過調節脈衝調光週期的責任週期可控 制光源的亮度》 ，圖1所示為傳統利用脈衝調光週期控制光源亮度之波 形圖圖1 (a)疋控制光源免度的脈衝調光信號m波形 圖。脈衝調光信號110在導通階段和關閉階段之間交替地 切換。導通階段的時間長度和關閉階段的時間長度可預先 设疋。圖1 (b)是在理想情況下，透過脈衝調光信號11〇 控制的流過光源的平均電流波形圖。光源的平均電流在脈 衝調光信號110的導通階段為基本上恒定的，且在脈衝調 光45號110的關閉階段為零。然而，在實際應用上，光源 可能和一電容並聯《在關閉階段，電容向光源放電，這樣， 電容的電壓將快速下降為零。在導通階段，電容電壓則逐 漸上升，且沒有電流流過光源直到電容電壓上升至一特定 位準。因此’流過光源的電流具有一啟動階段。圖1 (c) 為實際應用時’受脈衝調光信號110控制的流過光源的平 均電流波形圖。如圖1 (c)所示，光源的電流逐漸從零上 0653-TW-CH Spec+Claim(sandra.t-20100915).doc 4 201215227 升。在啟動階段，幾乎沒有電流流過光源。不同的實際應 用情況’則啟動階段的時間長度有所不同。因此，在脈衝 調光信號的導通階段，光源的平均電流的恒定時間長度是 不碟疋的’且在不同的應用狀況時亦有所不同。所以，無 法很精確的控制光源亮度，且光源亮度隨應用情況不同而 可能改變。 圖2所示為現有脈衝調光驅動電路2〇〇示意圖。脈衝 調光驅動電路200中包含由電感202、二極體204和開關 206所組成的轉換器將輸入電壓yIN轉換為輸出電壓以 對光源（例如，發光二極體串230)供電，且產生流過發光 二極體串230的一電流。脈衝調光驅動電路2〇〇還包括一 開關220、以及一與發光二極體串23〇以及開關22〇並聯 輕接之電谷240。開關220受控於一控制器21〇的ρ_υτ 接腳處的脈衝調光信號。控制器21〇的PWM接腳接收一脈 衝寬度調變信號。根據脈衝寬度調變信號，控制器21〇在 接腳PWMOUT處產生一具有導通階段和關閉階段之脈衝調 光“號。在關閉階段，開關220被關閉以斷開發光二極體 串230和電容240。因此，電容240的電壓以相對緩慢之 速度下降。當導通階段開始，開關22〇被導通，電容24〇 上的電壓仍在一特定位準上。這樣，相對於圖丨的現有技 術，可更快地建立流經發光二極體串230之電流。所以， 導通階段的精準度被改善。然而，由於額外的pWM〇UT接 腳和PWM接腳以及開關220，脈衝調光驅動電路2〇〇的成 本相對較高。 0653-TW-CH Spec+Claim(sandra.t-20100915).doc 5 201215227 【發明内容】 本發明的目的為提供一 檢測器，檢測一光源〃種光源調光控制器，包括：一 當該啟動階丄衝調光週期的一啟動階段，且 光週嶋-該脈衝調 器，_至該檢測器，觸發時一調光信號產生 脈衝調光週期的該導通階，時間長度為一預設時間段之該 脈衝產生器，耗接至該調信號;以及-以控制流經該光源的一電产二生^產生一脈衝信號 脈衝彥夺哭姑动Ab 机，其中，在該預設時間段，該 本發明^提:’ t該關閉階段，該脈衝產生器被除能。 照明系統，包括:-光源;-轉換 二輸===制信號將一輸入電能轉換為 制信號的-開關；==該2包括受控於該控 源根據流經該光源的一電流產生該控制信號，其令，該 關父替地在一脈衝調光週期的一預設導通階段被導 通，且在該脈衝調光週期的一關閉階段被斷開，且其中， /預叹導通心段從该電流的一啟動階段結束時開始。 ，本發明還提供-種光源調光控制方法，包括··檢測一 光源的-脈衝調光週期的一啟動階段，其中，該脈衝調光 週期包括一導通階段和一關閉階段；當該啟動階段結束 時，觸發時間長度為一預設時間段之該導通階段；利用多 個脈衝控制流經該光源的一電流；在該預設時間段致能該 多個脈衝；以及在該關閉階段除能該多個脈衝。 0653-TW-CH Spec+Claim(sandra.t-20100915).doc 6 201215227 【實施方式】 以下將對本發明的實施例給出詳細的說明。雖然本發 0，結合實施例進行㈣，但應理解這並非意指將本發明 =疋;^些實施例。相反地，本發明意在涵蓋*後附申請 利範圍所界定的本發明精神和範圍内所定義的各種變 化、修改和均等物。 此外在以下對本發明的詳細描述中，為了提供針對 本發明的完全的理解，提供了大量的具體細節。然而，於 籲 f技術領域巾具有财知識者將轉，沒有這些具體細 卽，本發明同樣可以實施。在另外的一些實例中，對於大 家熟知的方法、程序、元件和電路未作詳細描述，以便於 凸顯本發明之主旨。 、，本發明-實施例提供了根據脈衝調光週期控制光源調 光的控制器。控制器監測流經光源的電流以檢測脈衝調光 週，的啟動階段。-旦脈衝調光週期的啟動階段結束，控 制器觸發-預設時間段的脈衝調光週期的導通階段。有利 • 之處在於，脈衝調光週期的導通階段的精準度能獲得改 善，進而改善了光源調光控制的精準度。 圖3所示為根據本發明一實施例控制器3〇〇示意圖。 在圖3的例子中，控制器300包括檢測器32〇、脈衝調光 信號產生器340和脈衝產生器360。檢測器32〇監測流過 光源（圖3中未示）的電流，以檢測脈衝調光週期的啟動 P白多又，且當啟動階段結束時產生一觸發信號302❶在一實 施例中，啟動階段是指當光源被供電的初始，流過光源的 電流從初始值（例如，零）上升至預設電流位準的時間段。 0653-TW-CH Spec+Claim(sandra.t-20100915).doc 7 201215227 光源可包括發光二極體，但本發明不以此為限。 脈衝調光信號產生器340辆接至檢測器32〇，為回應 觸發信號302，可觸發時間長度為一預設時間段之脈衝調 光週期的導⑽段。脈衝產生H 耗接至脈衝調光信號 產生器340，可產生-控制信號咖（例如，脈衝信號）以控 制光源的調光。更確切的說，脈衝產生器36〇在脈衝調光 週期的導通賴被致能，且在脈衝賊週_關階段被 除能。例如，控制器300所產生之控制信號3〇6在導通階 段包含多個脈衝，且在關閉階段為低邏輯。 圖4所示為根據本發明一實施例耦接至光源（例如，發 光二極體串403)之控制器400示意圖。和圖3相同元件符 ϊ虎的元件具有相似功能。在圖4的例子中，控制器4〇〇包 括檢測器320、脈衝調光信號產生器34〇和脈衝產生器 360。在一實施例中，控制器4〇〇可整合於一積體電路中。 當流經發光二極體串403的電流的啟動階段結束時 (例如’當流經發光二極體串403的電流上升至一預設值 時），檢測器320產生一觸發信號302。在圖4的例子中， 檢測器320包括感應放大器422和比較器426。電阻401 和發光二極體串403串聯。在一實施例中，感應放大器422 透過控制器400的ISENP接腳和ISENM接腳接收電阻401 兩端的電壓，並輸出和電阻401上的壓降成比例的監測信 號Visen。這樣，監測信號？^„表示流過發光二極體串403 的電流。比較器426比較監測信號ViSen和一參考信號Vsetl， 當監測信號Visen和參考信號Vsetl之間之差值超過一臨限值 時，比較器426產生一觸發信號302。換言之，當流經發 0653-TW-CH Spec+C1aim(sandra.t-20100915).doc 8 201215227 光一極體串403的電流上升至一預設值時，檢測器320產 生觸發信號302。 脈衝調光信號產生器340產生一脈衝調光信號49〇以 控制脈衝產生器360。在圖4的例子中，脈衝調光信號產 生器340包括導通計時器442、調光週期計時器444、正反 器446、反及（NAND)閘448和開關449。在一實施例中，導 通計時器442和調光週期計時器444共用一時脈信號 CLK。導通計時器442係由比較器426所產生之觸發信號 • 302觸發。正反器446在C端接收導通計時器442的輸出， 以及在D端接收一電源供應電壓仰…調光週期計時器以4 提供一調光週期控制信號480給導通計時器442的重置端 Rn和正反器446的重置端Rn。反及閘448接收調光週期控 制信號480和正反器446在其輸出端⑽的輸出信號。 在圖4的例子中，開關449耦接於脈衝產生器36〇和 地之間，且受控於反及閘448的輸出。在一實施例中，當 開關449被導通，脈衝調光信號490被拉低至邏輯低，因 • 此，脈衝產生器360被除能。當開關449被斷開，脈衝調 光信號490被上拉至邏輯高，因此，脈衝產生器36〇被致 倉t*。開關449被交替地導通和斷開。脈衝產生器透過 控制器400的GATE接腳產生控制信號306。 圖5a所示為脈衝調光控制信號480、監測信號Visen、 導通計時器442的輸出、正反器446在QN端的信號、脈衝 調光信號490和控制信號3〇6之波形。圖5 (a)將結合圖 4進行描述。 調光週期計時器444交替地產生具有第一狀態（例 0653-TW-CH Spec+Claim(sandra.t-20丨〇〇9丨5)_d〇c 9 201215227 如’邏輯高）—時間段和第二狀態（例如，邏輯低）-時間段 之調光週期控制信號彻。當雛職㈣錢侧為第 二狀態時，導通計時器442和正反器446被重置，且正反 恭446的輸出端QN的信號為邏輯高。這樣，反及閘448 的兩個輸入分別為邏輯高和邏輯低，因此，反及閘桃的 輸出信號為邏輯高。所以，《 449被導通，脈衝調光信 號490為邏輯低。相應地，當調光週期控制信號480在第 二狀態時，脈衝產生器360被除能。 當調光週期控制信號480從第二狀態轉換至第一狀態 時’脈衝調光週期開始，這樣，流經發光二極體串4〇3的 電流開始增加。檢測器32〇透過比較表示流過發光二極體 串403的電流的監測信號Visen和參考信號％⑷，檢測脈衝 調光週期的啟動階段。導通計時器442不被觸發直至檢測 器320檢測到脈衝調光週期的啟動階段結束（例如，監測信 號ViSen和參考信號vset丨之間的差值超過一臨限值），且提供 觸發信號302給導通計時器442。導通計時器442開始計 數以回應觸發信號302，因此，脈衝調光週期的導通階段 開始。導通計時器442輸出一致能信號（例如，邏輯低）至 正反器446之輸入端C的一預設導通時間段。在預設導通 時間段，正反器446的輸出端QN的信號保持為邏輯高。由 於調光週期控制信號480處在第一狀態（例如，邏輯高）， 反及閘448產生一邏輯低，因此開關449被斷開。所以， 脈衝調光信號490為邏輯高，脈衝產生器360被致能一預 設導通時間段，並輸出包括脈衝的控制信號3〇6以控制發 光二極體串403的調光。 0653-TW-CH Spec+CIaim(sandra.t-20100915).doc 10 201215227 在一實施例中，當導通階段之預設時間段結束時，導 通a十時器442產生一上升沿（rising 6啦6)給正反器446 的輸入端C。為回應上升沿，正反器446的輸出端QN的信 號變為邏輯低，因此，反及閘448產生一邏輯高，以導通 開關449。所以，脈衝調光信號49〇為邏輯低且關閉階段 開始。相應地，脈衝產生器36〇被除能。流經發光二極體 串403的電流在關閉階段中可能下降至零。當調光週期控 制信號480從第一狀態轉換至第二狀態時，脈衝調光週期 _ 結束。當調光週期控制信號480從第二狀態轉換至第一狀 態時，新的脈衝調光週期開始。基於調光週期控制信號 480，脈衝調光信號產生器34〇產生脈衝調光信號49〇(例 如’脈衝寬度調變信號）致能或除能脈衝產生器36〇。 在一實施例中，控制器400還包括誤差放大器47〇。 誤差放大器470比較表示流經發光二極體串4〇3的電流的 監測仏號ViSen和另一參考信號yset2 ,以判斷流經發光二極 體串403的電流是否達到預設平均電流值。 φ 圖所示為監測信號Visen的波形以及脈衝產生器360 所產生之脈衝彳§波的責任週期。若平均電流小於預設平均 電流值，則誤差放大器470控制脈衝產生器360相應地增 加脈衝信號的責任週期。若平均電流大於預設平均電流 值，則誤差放大器470控制脈衝產生器36〇減小脈衝信號 的責任週期。 圖6所示為根據本發明另一實施例照明系統6〇〇示意 圖。在圖6的例子中，照明系統6〇()包括轉換器61〇、光 源620和控制器300。光源可包括發光二極體，但本發明 0653-TW-CH Spec+Claim(sandra.t-20100915).doc 11201215227 VI. Description of the Invention: [Technical Field] The present invention relates to a controller, particularly a light source dimming controller 0 [Prior Art] A pulse dimming period can be used to control a light source (for example, a light emitting diode) ) brightness. - A pulse dimming cycle includes a conduction phase and a shutdown phase. During the turn-on phase, multiple current pulses flow through the source, and during the off phase no current flows through the source. Therefore, the brightness of the light source can be controlled by adjusting the duty cycle of the pulse dimming period. Figure 1 shows the waveform of the brightness of the light source controlled by the pulse dimming period. Figure 1 (a) The pulse dimming signal for controlling the light source immunity m waveform diagram. The pulse dimming signal 110 alternates between an on phase and a off phase. The length of the conduction phase and the length of the shutdown phase can be preset. Figure 1 (b) is a graph showing the average current flowing through the light source controlled by the pulse dimming signal 11 在 under ideal conditions. The average current of the source is substantially constant during the turn-on phase of pulse dimming signal 110 and zero during the off phase of pulse dimming 45. However, in practical applications, the light source may be connected in parallel with a capacitor. In the off phase, the capacitor discharges to the source, so that the voltage of the capacitor will drop rapidly to zero. During the turn-on phase, the capacitor voltage gradually rises and no current flows through the source until the capacitor voltage rises to a specific level. Therefore, the current flowing through the source has a start-up phase. Fig. 1(c) is a graph showing the average current waveform flowing through the light source controlled by the pulse dimming signal 110 in practical use. As shown in Figure 1 (c), the current of the light source gradually rises from zero to 0653-TW-CH Spec+Claim(sandra.t-20100915).doc 4 201215227 liters. During the startup phase, almost no current flows through the source. The actual length of the application is different for the start-up phase. Therefore, during the conduction phase of the pulse dimming signal, the constant time length of the average current of the light source is non-disc and varies from application to application. Therefore, the brightness of the light source cannot be controlled very accurately, and the brightness of the light source may vary depending on the application. FIG. 2 is a schematic diagram of a conventional pulse dimming driving circuit 2 。. The pulse dimming driving circuit 200 includes a converter composed of the inductor 202, the diode 204 and the switch 206 to convert the input voltage yIN into an output voltage to supply power to the light source (for example, the LED string 230), and generate a stream. A current flowing through the LED string 230. The pulse dimming driving circuit 2A further includes a switch 220 and a battery valley 240 connected in parallel with the LED string 23〇 and the switch 22〇. Switch 220 is controlled by a pulse dimming signal at the ρ_υτ pin of a controller 21〇. The PWM pin of controller 21A receives a pulse width modulation signal. According to the pulse width modulation signal, the controller 21 generates a pulse dimming number having a conduction phase and a shutdown phase at the pin PWMOUT. In the off phase, the switch 220 is turned off to turn off the LED string 230 and the capacitor. 240. Thus, the voltage of capacitor 240 drops at a relatively slow rate. When the conduction phase begins, switch 22 is turned "on" and the voltage across capacitor 24 is still at a particular level. Thus, with respect to the prior art of FIG. The current flowing through the LED string 230 can be established more quickly. Therefore, the accuracy of the conduction phase is improved. However, due to the additional pWM〇UT pin and the PWM pin and the switch 220, the pulse dimming drive circuit 2 The cost of 〇〇 is relatively high. 0653-TW-CH Spec+Claim(sandra.t-20100915).doc 5 201215227 SUMMARY OF THE INVENTION The object of the present invention is to provide a detector for detecting a light source dimming control of a light source The method includes: when the start-up stage of the dimming period of the dimming period, and the optical 嶋-the pulse modulator, the detector is triggered, a dimming signal generates the conduction step of the pulse dimming period ,Time The pulse generator having a length of a predetermined period of time is consuming the signal; and - controlling a pulse of a pulse signal to generate a pulse signal is generated by the control unit flowing through the light source, wherein During the preset time period, the present invention provides that: the pulse generator is disabled. The illumination system includes: - a light source; - a conversion two === system signal converts an input power into -switching the signal -== the 2 includes controlling the source to generate the control signal according to a current flowing through the light source, so that the gate is replaced by a predetermined conduction period of a pulse dimming cycle Is turned on, and is turned off in a shutdown phase of the pulse dimming cycle, and wherein the /pre-spurt core segment begins from the end of a start phase of the current. The present invention also provides a light source dimming control method Including: detecting a start phase of a pulse dimming cycle of the light source, wherein the pulse dimming cycle includes a conduction phase and a shutdown phase; when the startup phase ends, the triggering time length is a preset time period The conduction phase; using multiple Controlling a current flowing through the light source; enabling the plurality of pulses during the predetermined period of time; and disabling the plurality of pulses during the shutdown phase. 0653-TW-CH Spec+Claim(sandra.t-20100915) MODE FOR CARRYING OUT THE INVENTION The following is a detailed description of the embodiments of the present invention. Although the present invention is based on the fourth embodiment, it should be understood that this is not intended to limit the invention. Rather, the invention is intended to cover various modifications, alternatives, and equivalents, which are defined by the scope of the invention, which is defined by the appended claims. A complete understanding provides a lot of specific details. However, the technical field of the technical field will be transferred. Without these specific details, the present invention can be implemented as well. In other instances, well-known methods, procedures, components, and circuits have not been described in detail in order to facilitate the invention. The present invention-embodiment provides a controller for controlling light source dimming based on a pulse dimming period. The controller monitors the current flowing through the source to detect the start-up phase of the pulse dimming week. Once the start phase of the pulse dimming cycle is over, the controller triggers the conduction phase of the pulse dimming cycle for the preset time period. It is advantageous that the accuracy of the conduction phase of the pulse dimming cycle can be improved, which improves the accuracy of the dimming control of the light source. FIG. 3 is a schematic diagram of a controller 3 according to an embodiment of the invention. In the example of FIG. 3, the controller 300 includes a detector 32A, a pulse dimming signal generator 340, and a pulse generator 360. The detector 32 detects the current flowing through the light source (not shown in FIG. 3) to detect the start of the pulse dimming cycle, and generates a trigger signal 302 when the start phase ends. In an embodiment, the startup phase It refers to the period during which the current flowing through the light source rises from an initial value (for example, zero) to a preset current level when the light source is powered. 0653-TW-CH Spec+Claim(sandra.t-20100915).doc 7 201215227 The light source may include a light emitting diode, but the invention is not limited thereto. The pulse dimming signal generator 340 is connected to the detector 32A. In response to the trigger signal 302, the pilot (10) segment of the pulse dimming period of a predetermined period of time can be triggered. The pulse generation H is consuming to the pulse dimming signal generator 340, which produces a control signal (e.g., a pulse signal) to control the dimming of the light source. More specifically, the pulse generator 36 is enabled in the pulse dimming cycle and is disabled during the pulse thief cycle. For example, the control signal 3 〇 6 generated by the controller 300 contains a plurality of pulses during the turn-on phase and low logic during the turn-off phase. 4 is a schematic diagram of a controller 400 coupled to a light source (e.g., light emitting diode string 403) in accordance with an embodiment of the present invention. The same components as in Figure 3 have similar functions. In the example of Fig. 4, the controller 4 includes a detector 320, a pulse dimming signal generator 34A, and a pulse generator 360. In an embodiment, the controller 4 can be integrated into an integrated circuit. The detector 320 generates a trigger signal 302 when the start phase of the current flowing through the LED string 403 ends (e.g., when the current flowing through the LED string 403 rises to a predetermined value). In the example of FIG. 4, detector 320 includes a sense amplifier 422 and a comparator 426. The resistor 401 and the LED string 403 are connected in series. In one embodiment, sense amplifier 422 receives the voltage across resistor 401 through the ISENP pin and ISENM pin of controller 400 and outputs a monitor signal Visen proportional to the voltage drop across resistor 401. So, monitor the signal? ^ „ indicates the current flowing through the LED string 403. The comparator 426 compares the monitor signal ViSen with a reference signal Vset1, and when the difference between the monitor signal Visen and the reference signal Vset1 exceeds a threshold, the comparator 426 A trigger signal 302 is generated. In other words, when the current flowing through the 0653-TW-CH Spec+C1aim(sandra.t-20100915).doc 8 201215227 light body string 403 rises to a predetermined value, the detector 320 generates Trigger signal 302. Pulse dimming signal generator 340 generates a pulse dimming signal 49A to control pulse generator 360. In the example of Figure 4, pulse dimming signal generator 340 includes a turn-on timer 442, dimming cycle timing The 444, the flip 446, the NAND gate 448 and the switch 449. In one embodiment, the on timer 442 and the dimming period timer 444 share a clock signal CLK. The on timer 442 is controlled by a comparator. The trigger signal generated by 426 is triggered by 302. The flip-flop 446 receives the output of the on-time timer 442 at the C terminal, and receives a power supply voltage at the D terminal. The dimming period timer provides a dimming period control signal. 480 guide The reset terminal Rn of the timer 442 and the reset terminal Rn of the flip-flop 446. The inverse gate 448 receives the dimming period control signal 480 and the output signal of the flip-flop 446 at its output terminal (10). In the example of FIG. The switch 449 is coupled between the pulse generator 36 and ground and is controlled by the output of the inverse gate 448. In one embodiment, when the switch 449 is turned on, the pulse dimming signal 490 is pulled low to logic low. Because of this, the pulse generator 360 is disabled. When the switch 449 is turned off, the pulse dimming signal 490 is pulled up to a logic high, and therefore, the pulse generator 36 is asserted t*. The switch 449 is alternately Turning on and off. The pulse generator generates a control signal 306 through the GATE pin of the controller 400. Figure 5a shows the pulse dimming control signal 480, the monitoring signal Visen, the output of the on timer 442, and the flip 446 in the QN. The waveform of the terminal, the pulse dimming signal 490 and the control signal 3 〇 6. Figure 5 (a) will be described in conjunction with Figure 4. The dimming cycle timer 444 alternately produces the first state (eg, 0653-TW-CH Spec +Claim(sandra.t-20丨〇〇9丨5)_d〇c 9 201215227 as 'logic high' The time period and the second state (eg, logic low) - the dimming period control signal of the time period is complete. When the parent (4) money side is the second state, the on timer 442 and the flip-flop 446 are reset, and The signal of the output terminal QN of the counter 446 is logic high. Thus, the two inputs of the inverse gate 448 are logic high and logic low, respectively, and therefore, the output signal of the inverse gate is logic high. Therefore, "449 is turned on and the pulse dimming signal 490 is logic low. Accordingly, when the dimming period control signal 480 is in the second state, the pulse generator 360 is disabled. When the dimming period control signal 480 transitions from the second state to the first state, the pulse dimming period begins, so that the current flowing through the LED string 4〇3 begins to increase. The detector 32 detects the start-up phase of the pulse dimming period by comparing the monitor signal Visen indicating the current flowing through the light-emitting diode string 403 with the reference signal %(4). The turn-on timer 442 is not triggered until the detector 320 detects the end of the start phase of the pulse dimming cycle (eg, the difference between the monitor signal ViSen and the reference signal vset丨 exceeds a threshold) and provides a trigger signal 302 to Turn on the timer 442. The turn-on timer 442 begins counting in response to the trigger signal 302, and thus, the turn-on phase of the pulse dimming cycle begins. The turn-on timer 442 outputs a coincidence energy signal (e.g., logic low) to a predetermined on-time period of the input terminal C of the flip-flop 446. During the preset on-time period, the signal at the output QN of the flip-flop 446 remains at a logic high. Since the dimming cycle control signal 480 is in the first state (e.g., logic high), the AND gate 448 produces a logic low, so the switch 449 is turned off. Therefore, the pulse dimming signal 490 is logic high, the pulse generator 360 is enabled for a predetermined on-time period, and a control signal 3〇6 including the pulse is output to control dimming of the light-emitting diode string 403. 0653-TW-CH Spec+CIaim(sandra.t-20100915).doc 10 201215227 In an embodiment, when the preset time period of the conduction phase ends, the conduction a ten timer 442 generates a rising edge (rising 6 6) Give the input C of the flip-flop 446. In response to the rising edge, the signal at the output QN of the flip-flop 446 becomes logic low, so the inverse gate 448 produces a logic high to turn on the switch 449. Therefore, the pulse dimming signal 49 is logic low and the off phase begins. Accordingly, the pulse generator 36 is disabled. The current flowing through the LED string 403 may drop to zero during the shutdown phase. When the dimming period control signal 480 transitions from the first state to the second state, the pulse dimming period _ ends. When the dimming cycle control signal 480 transitions from the second state to the first state, a new pulse dimming cycle begins. Based on the dimming period control signal 480, the pulse dimming signal generator 34 generates a pulse dimming signal 49 (e.g., 'pulse width modulation signal') to enable or disable the pulse generator 36A. In an embodiment, the controller 400 also includes an error amplifier 47A. The error amplifier 470 compares the monitor nickname ViSen indicating the current flowing through the illuminating diode string 4〇3 with another reference signal yset2 to determine whether the current flowing through the illuminating diode string 403 reaches a preset average current value. The φ diagram shows the duty cycle of the monitor signal Visen and the duty cycle of the pulse generator generated by the pulse generator 360. If the average current is less than the preset average current value, the error amplifier 470 controls the pulse generator 360 to increase the duty cycle of the pulse signal accordingly. If the average current is greater than the preset average current value, the error amplifier 470 controls the pulse generator 36 to reduce the duty cycle of the pulse signal. Figure 6 is a schematic illustration of a lighting system 6 in accordance with another embodiment of the present invention. In the example of Fig. 6, the illumination system 6() includes a converter 61A, a light source 620, and a controller 300. The light source may include a light emitting diode, but the present invention is 0653-TW-CH Spec+Claim (sandra.t-20100915).doc 11
S 201215227 不以此為限。和圖3相同元件符號之元件具有相似功能。 根據控制器300所產生之控制信號306，耦接至光源 620的轉換器610將輸入電能p1N轉換為輸出電能ρ·，以 對光源620供電。透過調節控制信號306，輸出電能ρουτ 可被控制進而調節流經發光二極體串403的電流。這樣， 光源620的亮度可受到控制。 圖7所示為根據本發明另一實施例照明系統7〇〇示意 圖。和圖6相同元件符號之元件具有相似功能。在圖γ的 例子中，控制器300可整合在積體電路中。有利之處在於， 相較於圖2 ’本發明可省去額外之接腳（例如，pwM接腳和 PWMOUT接腳）且開關32〇亦可省去，因此，可降低成本。 轉換器610包括開關706、電感702和二極體704。控制器 300之接腳ISENP和接腳ISENM可用以感應串聯耦接至光 源620之電阻上的壓降，進而感應流經光源的電流。 控制器300可根據感應到之電流，在接腳GATE處產生控制 信號306。轉換器610的開關706受控於控制信號3〇6,進 而控制光源620的調光。開關706在脈衝調光週期的導通 階段被交替地導開通和斷開，且在脈衝調光週期的關閉階S 201215227 is not limited to this. Elements of the same component symbol as in Figure 3 have similar functions. Based on the control signal 306 generated by the controller 300, the converter 610 coupled to the light source 620 converts the input electrical energy p1N into an output electrical energy ρ· to power the light source 620. By adjusting the control signal 306, the output electrical energy ρουτ can be controlled to adjust the current flowing through the LED string 403. Thus, the brightness of the light source 620 can be controlled. Figure 7 is a schematic illustration of an illumination system 7 in accordance with another embodiment of the present invention. Elements of the same component symbol as in Figure 6 have similar functions. In the example of the figure γ, the controller 300 can be integrated in the integrated circuit. Advantageously, the present invention eliminates the need for additional pins (e.g., pwM pins and PWMOUT pins) and the switch 32A can be omitted as compared to Figure 2, thereby reducing cost. Converter 610 includes a switch 706, an inductor 702, and a diode 704. The pins ISENP and pins ISENM of the controller 300 can be used to sense the voltage drop across the resistors coupled in series to the source 620, thereby sensing the current flowing through the source. Controller 300 can generate control signal 306 at pin GATE based on the sensed current. Switch 706 of converter 610 is controlled by control signal 3〇6 to control dimming of light source 620. Switch 706 is alternately turned on and off during the on phase of the pulse dimming cycle, and is turned off during the dimming period of the pulse.
段被持續斷開。在一實施例中，開關7〇6可和控制器加〇 一同整合於1C晶片中。 I 圖8所示為根據本發明一實施例控制光源調光的方法 流程圖800。® 8將結合® 3和圖4進行描述。雖然㈣ 中公佈了具體的步驟，這些步驟為例^也就是說，本發 明也適用於圖8中步驟的變化。 在步驟802中，檢測器32〇檢測發光二極體串4〇3的 0653-TW-CH Spec+Claim(sandra.t-20100915).doc \2 201215227 脈衝調光週期的啟動階段。在一實施例中，檢測器32〇中 的比較器426比較表示流經發光二極體串伽的電流的監 測信號Vi sen和一預設值。 在步驟804巾，當啟動階段結束時，檢測器32〇產生 觸發诚3G2給導通計時器442，以觸發時間長度為一預 設時間段之脈衝調光週期的導通階段。 在步驟806巾，脈衝產生器36〇產生多個脈衝以控制 流經發光二極體串403的電流。 • 在步驟808中’在脈衝調光週期的導通階段致能多個 脈衝:如圖5所述，在導通階段，正反器權的輸出端⑽ 處的信號為邏輯高，調光週期計時器444所輸出的脈衝調 光控制仏號480為邏輯高。因此，反及閘448的輸出信號 為邏輯低，因此開關449被斷開。所以，在導通階段，脈 衝產生器360被致能，進而輸出多個脈衝以控制流經發光 二極體串403的電流。 、 在步驟810中，在脈衝調光週期的關閉階段除能多個 • 脈衝’如圖5所述’在關閉階段，正反器446的輸出端qN 處的信號為邏輯低，調光週期控制信號48〇為邏輯高。因 此，反及閘448的輸出信號為邏輯高，因此開關449被導 通。所以，在關閉階段，脈衝產生器36〇被除能。 上文具體實施方式和附圖僅為本發明之常用實施 例。顯然，在不脫離權利要求書所界定的本發明精神和發 明範圍的前提下可以有各種增補、修改和替換。本領域技 術人員應該理解，本發明在實際應用中可根據具體的環境 和工作要求在不背離發明準則的前提下在形式、結構、佈 0653-TW-CH Spec+Claim(sandra.t-20100915).doc 13 201215227The segment is continuously disconnected. In one embodiment, switch 7〇6 can be integrated into the 1C wafer along with the controller twist. Figure 8 is a flow chart 800 of a method of controlling dimming of a light source in accordance with an embodiment of the present invention. ® 8 will be described in conjunction with ® 3 and Figure 4. Although specific steps are disclosed in (d), these steps are examples. That is, the present invention is also applicable to the variation of the steps in FIG. In step 802, the detector 32 detects the start-up phase of the 0653-TW-CH Spec+Claim (sandra.t-20100915).doc \2 201215227 pulse dimming period of the LED string 4〇3. In one embodiment, comparator 426 in detector 32A compares the pilot signal Vi sen indicative of the current flowing through the LED string and a predetermined value. At step 804, when the start-up phase is over, the detector 32 generates a trigger 3G2 to the turn-on timer 442 to trigger a turn-on phase of the pulse dimming period for a predetermined period of time. At step 806, the pulse generator 36 generates a plurality of pulses to control the current flowing through the LED string 403. • In step 808 'Enable multiple pulses during the turn-on phase of the pulse dimming cycle: as shown in Figure 5, during the turn-on phase, the signal at the output (10) of the flip-flop is logic high, dimming cycle timer The pulse dimming control nickname 480 output by 444 is logic high. Therefore, the output signal of the inverse gate 448 is logic low, so the switch 449 is turned off. Therefore, in the conducting phase, the pulse generator 360 is enabled to output a plurality of pulses to control the current flowing through the LED string 403. In step 810, in the off phase of the pulse dimming cycle, multiple pulses are disabled. As shown in FIG. 5, in the shutdown phase, the signal at the output terminal qN of the flip-flop 446 is logic low, and the dimming period control is performed. Signal 48〇 is logic high. Therefore, the output signal of the inverse gate 448 is logic high, so the switch 449 is turned on. Therefore, in the off phase, the pulse generator 36 is disabled. The above detailed description and the drawings are merely illustrative of the common embodiments of the invention. It is apparent that various additions, modifications and substitutions are possible without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood by those skilled in the art that the present invention can be applied in the form, structure, and cloth in the form, structure, and cloth in accordance with the specific environmental and working requirements without departing from the invention guidelines. 0653-TW-CH Spec+Claim(sandra.t-20100915) .doc 13 201215227
局、比例、材料、元素 。因此， 丨’本發明之範圍由 而不限於此前之描 在此彼露之實施例僅用於說明而非限制 後附權利要求及其合法等同物界定^， 述。 1 【圖式簡單說明】 以下結合附圖和具體實Bureau, proportion, materials, elements. Therefore, the scope of the present invention is defined by the scope of the appended claims. 1 [Simple description of the drawings] The following is a combination of the drawings and the concrete
…,文‘始又句明顯。再中. 圖1所示為傳統利用脈衝調光週 形圖。 圖2所示為現有脈衝調光驅動電路示意圖。 圖3所示為根據本發明一實施例控制器示意圖。 圖4所示為根據本發明一實施例耦接至光源之控制器 示意圖。 圖5a所示為脈衝調光控制信號、監測信號仏咖、導通 計時器的輸出、正反器在QN端的信號、脈衝調光信號和 控制信號之波形。 圖5b所示為監測信號visen的波形以及脈衝產生器360 所產生之脈衝信號的責任週期。 圖6所示為根據本發明一實施例照明系統示意圖。 圖7所示為根據本發明另一實施例照明系統示意圖。 圖8所示為根據本發明一實施例控制光源調光的方法 流程圖。 【主要元件符號說明】 110 :脈衝調光信號 0653-TW-CHSpec+CIaim(sandra.t-20100915).doc 14 201215227..., the text 'begins and sentences are obvious. Again, Figure 1 shows a conventional pulse dimming pattern. Figure 2 shows a schematic diagram of a conventional pulse dimming drive circuit. 3 is a schematic diagram of a controller in accordance with an embodiment of the present invention. 4 is a schematic diagram of a controller coupled to a light source in accordance with an embodiment of the present invention. Figure 5a shows the pulse dimming control signal, the monitoring signal, the output of the on-time timer, the signal of the flip-flop at the QN terminal, the pulse dimming signal, and the waveform of the control signal. Figure 5b shows the duty cycle of the monitor signal visen and the pulse signal generated by the pulse generator 360. Figure 6 is a schematic illustration of an illumination system in accordance with an embodiment of the present invention. Figure 7 is a schematic illustration of an illumination system in accordance with another embodiment of the present invention. Figure 8 is a flow chart showing a method of controlling dimming of a light source in accordance with an embodiment of the present invention. [Main component symbol description] 110 : Pulse dimming signal 0653-TW-CHSpec+CIaim(sandra.t-20100915).doc 14 201215227
200 ： 脈衝調光驅動電路 202 ： 電感 204 ： 二極體 206 ： 開關 210 ： 控制器 220 ： 開關 230 : 發光二極體串 240 ： 電容 300 ： 控制器 302 ： 觸發信號 306 ： 控制信號 320 ： 檢測器 340 : 脈衝調光信號產生器 360 ： 脈衝產生器 400 ： 控制器 401 ： 電阻 403 ： 發光二極體串 422 ： 感應放大器 426 ： 比較器 442 ： 導通計時Is 444 ： 調光週期計時器 446 ： 正反器 448 ： 反及（NAND)閘 449 ： 開關 470 ： 誤差放大器 0653-TW-CH Spec+CIaim(sandra.t-2：0100915).doc 15 201215227 480 :調光週期控制信號 490 :脈衝調光信號 600 :照明系統 610 :轉換器 620 :光源 700 ··照明系統 702 :電感 704 :二極體 706 :開關 800 :流程圖 802、804、806、808、810 :步驟200 : Pulse dimming drive circuit 202 : Inductor 204 : Diode 206 : Switch 210 : Controller 220 : Switch 230 : LED string 240 : Capacitor 300 : Controller 302 : Trigger signal 306 : Control signal 320 : Detection 340: pulse dimming signal generator 360: pulse generator 400: controller 401: resistor 403: light emitting diode string 422: sense amplifier 426: comparator 442: conduction timing Is 444: dimming period timer 446: Transponder 448: NAND gate 449: Switch 470: Error amplifier 0653-TW-CH Spec+CIaim(sandra.t-2:0100915).doc 15 201215227 480: Dimming period control signal 490: Pulse modulation Optical signal 600: illumination system 610: converter 620: light source 700 · illumination system 702: inductor 704: diode 706: switch 800: flowcharts 802, 804, 806, 808, 810: steps
0653-TW-CH Spec+Claim(sandra.t-20100915).doc 160653-TW-CH Spec+Claim(sandra.t-20100915).doc 16