201037213 六、發明說明： 【發明所屬之技術領域】 本發明關於一種發光裝置。 【先前技術】 發光二極體（Light-Emitting Diode, LED)，是一種半 、 導體元件，初時多作為指示燈以及戶外顯示板之光源。由 於發光二極體具有效率南、命長以及不易破損等傳統光 0 源無法達到的優點，因此發光二極體已被廣泛地運用至許 多種類的電子產品中。 以發光二極體為光源的發光裝置，其控制方法，一般 而言可分為定電壓控制以及定電流控制。請參照圖1A所 示，習知定電壓控制的發光裝置1A包含一發光二極體模 組11、一電容器12、複數電阻器13及一定電壓源14。為 了使輸入發光二極體的訊號為一定電壓訊號，設計人員通 常必須採用大電容值的電容器，或是較為複雜的整流電 〇 w 路，藉此達到穩壓的效果，因而會增加製造成本。 ^ 雖然，定電壓控制具有較簡易的電路設計之優點，但 定電壓控制並無法提供一穩定的電流。由於發光二極體是 藉由電子與電洞的結合，使過剩的能量以光的形式釋出， 而達成發光的效果。因此，電流的改變將對發光二極體的 發光特性有極大的影響。換句話說，定電壓控制係無法精 確的控制發光二極體的發光特性。 另外，請參照圖1B所示，習知定電流控制的發光裝 201037213 置1B包3 一發光二極體模組n、一電容器u、複數電阻 =13、定電流源15及一偵測單元16。雖然，習知的定電 流控制可以提供發光二極體穩定的電流，但在實際的運用 為了克服因各發光二極體之間的差異而產生的電流差 二仍須使用電阻裔13作為限流元件，以吸收因電性變 而k成的功率差異以穩定電流，如此—來，將造成 的功率損耗。 然而，無論是習知定電墨控制的發光裝置或是習知定 =:控制的發光裝置’均需要—個能夠提供敎電源的供 =進=如何提供一種發光裝置，使其能夠藉由可 進仃驅動，同時又能夠避免功率損耗在限流元件， &升功率的使用效率，已成為重要課題之-。 【發明内容】 有鑑於上述課題，本發明之目的為提供 可變電源進行驅動，同時又m μ裡⑽错由 , , 」吋又此夠避免功率損耗在限流元 牛’以提升功率的制效率的發光裝置。 光目的，依據本發明之一種發光裝置包含-先-極體杈組、—偵測電路以 模組接收一可轡雷厭处、， 發先一極 。偵測電路偵測可變電壓之一⑬ =，並依據電壓準位輸出„控制訊號。^ 發光二極體模組内導通之發光二極體之數量Λ虎調 承上所途’依據本發明之一種發光裝置係藉由控制 201037213 路調整發光二極體模組内導通之發光二極體之數量。與習 知技術相較，本發明可藉由改變導通之發光二極體之數 量，而使發光二極體模組操作於一預設狀態，從而實現能 夠藉由可變電源進行驅動，同時又能夠避免功率損耗在限 流元件，以提升功率的使用效率的發光裝置。 - 【實施方式】 以下將參照相關圖式，說明依據本發明較佳實施例之 0 一種發光裝置，其中相同的元件將以相同的參照符號加以 說明。 請參照圖2所示，圖2為本發明較佳實施例之一種發 光裝置的示意圖。發光裝置2包含一發光二極體模組21、 一偵測電路22及一控制電路23。 發光二極體模組21接收一可變電壓V。在本實施例 中，發光二極體模組21包含複數串聯之發光二極體單元 _ 211，而發光二極體單元211分別包含至少一發光二極體。 〇 在本實施例中，可變電壓v可為一交流電壓或一直流 - 電壓，可變電壓v係為隨著時間會以週期性或隨機的改變 - 其準位的電壓，意即其為不固定的電壓。其中，前述之交 流電壓可為一般熟知的市電，意即為90V至250V的交流 電，亦可為由電源轉換器所輸出之交流電。另外，前述之 直流電壓係包括由電池、電瓶或交流電壓經由一整流電路 而產生之電壓。其中，電池與電瓶因使用時間的增加，將 201037213 ==壓之準位產生變動，此外，經由整流電路所產 ^«則健縣較。因此，在實際 類直流電塵的準位仍會隨著時間而改變。 债測％路22债測可變電魔v之一 ”:!Γ訊號，。在實施上 不同產口 ώΌ 一 力Γ俱判電路22亦可依據 外，^ h際上設計的需要而為—積體電路。此 貫際運用上，偵測電路22可為— 葬廿SPH主伯、， 巧即叫侦測電路’ 藉此即時_可變電壓v之電壓準位的變化。 控制電路2 3分別與發光二極體 雷松 、， 脰稞、，且及偵測電路22 ，亚根據控制訊號S調整發光_ 導通之發光二極體之數量。在^上t 内 -數位控制電路或一類比4;:二制電路23可為 φ „ , 頰比彳工制電路，而發光二極體模組21 制^ —發光二極體單元211不受控制電路23的控 卜+，在本實施例中，控制電路23可為一積體電路。 在本m參㈣3’以進—步說明本發明之發光裝置。 -第η光二極體模組31包含相互串聯連接之 祀弟一乂光二極體單元311及一第二發光二極體單元 外，在貫施上，第一發光二極體單元311及第二 =極體單元312中的發光二極體係可為先串聯連接， 再马連接，及或先並聯連接，再串聯連接。 並中控制電i33包含一切換單元331及一控制單元332。 技，切換早兀331與第二發光二極體單元312電性連 接。控制單元332與切換單元331及摘測電路％電性連 201037213 接，控制單兀332並接收由偵測電路32所產生的控制訊 號Sc。在實施上，切換單元係包含雙載子電晶體（b厂门 或場效電晶體（ΡΈΤ)。 θ在本實施例中，係藉由控制單元332判斷控制訊號心 疋否小於一預設值，且控制單元332將依據判斷結果控制 切換單元331 ’以使切換單元331操作於導通或截止狀離。 •亦^控制電路33將可依據控制訊號&，截止或導通第 一發光二極體單元312，而使發光二極體模組Η操作於一 〇 預設電流值。 、 品左思的是，在本貫施例中，第一發光二極體單元 並不受控制單元33之控制，且俄測電路32為一即時制 電路。在此，所謂的不受控制係為第一發光二極體單元3ιι 的發光與否係由電源所控制，而控制電路％的作動將不 直接影響第一發光二極體單元3ιι的發光與否，然，兩者 在電性上仍有連接關係。 ❹^藉由上述之硬體架構，本發明將能夠即時偵測可變電 .f V之㈣準位的變化，而改變導通之發光二極體之數 里’以使發光二極難崎作於—預設狀態，進而提升功 率的使用效率。如此一來，本發明之發光裝置將不受限於 電源供應單元必須提供一穩定之電源。 此外，在實際運用上，控制電路的架構係可以依據不 同的需求而有不同的變化態樣，以下請參照圖4A及圖 4B舉例祝明控制電路的二種應用架構。 201037213 如圖4A所示，本實施例為了方便說明，係以發光二 極體模組具有四個發光二極體單元為例。然而，並非以此 為限。 發光二極體模組41A包含四個串聯連接之發光二極體 單元4H。控制電路43包含複數切換單元431及一控制單 元432。其中，各切換單元431分別與相對應之發光二極 體單元411電性連接，且各切換單元431係為相互並聯連 接。此外，控制單元432與偵測電路42電性連接。 在實際運用上，控制單元432可包含一移位暫存器及 一比較器。其中，移位暫存器分別與各切換單元431電性 連接，而比較器分別與移位暫存器及偵測電路42電性連 接，並接收由偵測電路42所產生的控制訊號Sc。控制電 路432將藉由比較器判斷控制訊號Sc是否小於一預設值， 並依據判斷結果控制各切換單元431，以分別截止或導通 各發光二極體單元411，而使發光二極體模組41A操作於 一預設電流值。 接著，請參照圖4B及圖5，以下將進一步說明發光裝 置4B操作於交流電壓時，一種調整發光二極體之數量的 方式。此外，本實施例係以定電流（80mA)通過所有發光 二極體單元為例，然其並非以此為限。 本實施例中，可變電壓V係如圖5所示，為一交流電 壓。其中，可變電壓V由低壓至高壓係可區分為四個區段。 第一區段R1時，發光二極體模組的工作週期（Duty)為 201037213 85% ;第二區段R2時，發光二極體模組的工作週期為 70% ;第三區段R3時，發光二極體模組的工作週期為 50%;第四區段R4時，發光二極體模組的工作週期為25%。 如圖4B所示，發光裝置4B之發光二極體模組41B 包含四個串聯連接之發光二極體單元411A、411B、411C、 411D。其中，發光二極體單元411A、411B、411C是分別 ' 包含四個、三個及二個並聯連接的發光二極體。 控制電路43包含第一切換單元431A、第二切換單元 ® 431B、第三切換單元431C及一控制單元432。其中，各 切換單元431A〜431C分別與相對應之發光二極體單元 411A〜411D電性連接，且各切換單元431A〜431C係為相 互串聯連接。 偵測電路42與控制單元432電性連接，並偵測可變 電壓V之電壓準位的變化。當可變電壓V之電壓準位是位 於第一區段R1時，發光二極體單元411A依據所接收之可 〇 變電壓V而發光；當可變電壓V之電壓準位是位於第二區 段R2時，偵測電路42輸出控制信號至控制單元432，以 '截止第一切換單元431A，而導通發光二極體單元411A、 • 411B ;當可變電壓V之電壓準位是位於第三區段R3時， 偵測電路42輸出控制信號至控制單元432,以截止第一切 換單元431A及第二切換單元431B，而導通發光二極體單 元411A〜411C ;當可變電壓V之電壓準位是位於第四區 段R4時，偵測電路42輸出控制信號至控制單元432，以 201037213 截止第一切換單元431A、第二切換單元431B及第三切換 單元431C，而導通發光二極體單元411A〜411D。 換句話說，電壓準位在第一區段R1時，流經發光二 極體單元411A之各發光二極體的電流為20mA;電壓準位 在第二區段R2時，新增流經發光二極體單元411B之各發 光二極體的電流為26.6mA ;電壓準位在第三區段R3時， 再新增流經發光二極體單元411C之各發光二極體的電流 為40mA ;電壓準位在第四區段R4時，再新增流經發光二 極體單元411D之發光二極體的電流為80mA。此時，在一 個週期時間内，各發光二極體單元411A〜411D的輸出功 率比將為 17 : 18.62 : 20 : 20。 在實際操作上，更可於發光裝置的電路中加入電容， 以延長第一區段及第二區段的工作週期為100%與75%， 進而使各發光二極體單元的輸出功率比形成20 : 20 : 20 : 20 ° 藉由圖4B所示之硬體結構，本發明將可藉由改變各 發光二極體單元中導通之發光二極體之數量，而使各發光 二極體單元具有相近或是相同的輸出功率。 另外，值得一提的是，本發明並不限定各發光二極體 單元中所包含的發光二極體數量，以及各發光二極體單元 中之發光二極體的連接方式。此外，本發明之發光裝置係 可為一背光源或一照明裝置，並可應用於行動通訊領域、 交通運輸工具之照明領域及一般照明應用領域。 10 201037213 、、vr'上所述，因依據本發明之發光裝置，係藉由控制電 調整發光二極體模組内導通之發光二極體之數量。與習 旦W相車乂本考务明可藉由改變導通之發光二極體之數 里而使舍光―極體模組操作於一預設狀態，從而實現能 $藉由可變電源進行㈣，同時又能夠避免功率損耗在限 L元件U &升功率的使用效率的發光裝置。 〇 以上所述僅為舉例性，而非為限制性者。任何未脫離 本毛明之精神與範嘴，而對其進行之等效修改或變更，均 應包含於後附之申請專利範圍中。 【圖式簡單說明】 圖1A為習知定電壓控制之發光裝置的意圖； 圖1B為習知定電流控制之發光裝置的意圖； 圖2為本發明較佳實施例之一種發光裝置的示意圖； 圖3為本發明較佳實施例之一種發光裝置的示意圖； 〇 圖4A至圖4B為本實施例之發光裝置具有不同變化態 樣的示意圖；以及 圖5為本發明之發光裝置搭配使用之交流電壓的示意 【主要元件符號說明】 ΙΑ、1B、2、3、4A、4B :發光裝置 11、21、31、41A、41B :發光二極體模組 11 201037213 12 :電容器 13 :電阻器 14 :定電壓源 15 :定電流源 16 :彳貞測單元 211、411、411A、411B、411C、411D :發光二極體單元 22、 32、42 :偵測電路 23、 33、43 :控制電路 311 :第一發光二極體單元 312 :第二發光二極體單元 331 :切換單元 332、432 :控制單元 431 :切換單元 431A :第一切換單元 431B ··第二切換單元 431C :第三切換單元 R1 :第一區段 R2 :第二區段 R3 :第三區段 R4 :第四區段 S c :控制訊號 V :可變電壓 12201037213 VI. Description of the Invention: [Technical Field of the Invention] The present invention relates to a light-emitting device. [Prior Art] A Light-Emitting Diode (LED) is a semi-conductor component that is used as an indicator light and a light source for an outdoor display panel at an early stage. Light-emitting diodes have been widely used in many types of electronic products because of their advantages such as efficiency, south length, and resistance to breakage, which are not achievable by conventional light sources. The light-emitting device using the light-emitting diode as a light source, the control method thereof, can be generally divided into constant voltage control and constant current control. Referring to FIG. 1A, the conventional voltage-controlled light-emitting device 1A includes a light-emitting diode module 11, a capacitor 12, a plurality of resistors 13, and a constant voltage source 14. In order to make the signal of the input LED a certain voltage signal, the designer usually has to use a capacitor with a large capacitance value or a complicated rectifier circuit to achieve the voltage stabilization effect, thereby increasing the manufacturing cost. ^ Although constant voltage control has the advantage of a simple circuit design, constant voltage control does not provide a stable current. Since the light-emitting diode is combined with electrons and holes, the excess energy is released in the form of light to achieve the effect of light emission. Therefore, the change in current will have a great influence on the luminescence characteristics of the light-emitting diode. In other words, the constant voltage control system cannot accurately control the light-emitting characteristics of the light-emitting diode. In addition, please refer to FIG. 1B , the conventional constant current control illuminating device 201037213 is set to 1B package 3 a light emitting diode module n, a capacitor u, a complex resistance = 13, a constant current source 15 and a detecting unit 16 . Although the conventional constant current control can provide a stable current of the light-emitting diode, in practice, in order to overcome the current difference caused by the difference between the light-emitting diodes, it is necessary to use the resistor 13 as the current limit. Components, in order to absorb the power difference due to electrical changes to stabilize the current, and thus, will cause power loss. However, whether it is a conventional light-controlled ink-controlled device or a conventionally-controlled light-emitting device, it is required to provide a light-emitting device that can provide a light-emitting device so that it can be provided by Into the drive, while avoiding power loss in the current-limiting components, & power utilization efficiency has become an important issue -. SUMMARY OF THE INVENTION In view of the above problems, the object of the present invention is to provide a variable power supply for driving, and at the same time, m μ mile (10) is wrong, and 够 够 够 够 够 够 够 够 避免 避免 避免 避免 避免 功率 功率 功率 功率 功率 功率 功率 功率 功率 功率 功率 功率 功率 功率 功率 功率Efficient lighting device. For the purpose of light, a light-emitting device according to the present invention comprises a -first-pole body group, and a detecting circuit receives a clickable pole with a module, and generates a first pole. The detecting circuit detects one of the variable voltages 13 = and outputs a control signal according to the voltage level. ^ The number of the light-emitting diodes in the light-emitting diode module is controlled by the tiger. According to the present invention One type of light-emitting device adjusts the number of light-emitting diodes that are turned on in the light-emitting diode module by controlling 201037213. Compared with the prior art, the present invention can change the number of light-emitting diodes that are turned on. The light-emitting diode module is operated in a preset state, thereby realizing a light-emitting device capable of being driven by a variable power source while avoiding power loss in the current limiting element to improve power use efficiency. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a light-emitting device according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings, wherein the same elements will be described with the same reference numerals. Referring to Figure 2, Figure 2 is a preferred embodiment of the present invention. A schematic diagram of a light-emitting device. The light-emitting device 2 includes a light-emitting diode module 21, a detecting circuit 22 and a control circuit 23. The light-emitting diode module 21 receives a variable voltage V. In this embodiment, the LED module 21 includes a plurality of LED units 211 in series, and the LED units 211 respectively include at least one LED. In this embodiment, The variable voltage v can be an alternating voltage or a direct current-voltage, and the variable voltage v is a periodic or random change with time - the voltage of its level, that is, it is an unfixed voltage. The AC voltage can be a commonly known commercial power, that is, an AC power of 90V to 250V, or an AC power output by the power converter. In addition, the DC voltage includes a battery, a battery or an AC voltage via a rectifier circuit. The voltage generated, in which the battery and the battery increase due to the use of time, will change the level of 201037213 == pressure, in addition, through the rectifier circuit produced ^ « then Jianxian. Therefore, in the actual class of DC dust Bits will still change with time. Debt measurement% road 22 debt measurement variable electric magic v ""!! Γ signal,. In the implementation of different production ports, the circuit 22 can also be based on the external design requirements of the integrated circuit. In this application, the detecting circuit 22 can be used to bury the voltage level of the variable voltage v by suffocating the SPH master, which is called the detecting circuit. The control circuit 23 respectively adjusts the number of the light-emitting diodes that are illuminated and turned on according to the light-emitting diodes Raysund, 脰稞, and the detecting circuit 22, according to the control signal S. In the t-intra-digit control circuit or an analogy 4;: the two-circuit circuit 23 can be φ „ , the cheek ratio is a circuit, and the light-emitting diode module 21 is not illuminated by the LED unit 211 The control circuit 23 can be an integrated circuit. In the present embodiment, the control circuit 23 can be an integrated circuit. The light-emitting device of the present invention will be described in the following paragraphs: 4. The η-light diode module 31 In addition to the second light-emitting diode unit 311 and the second light-emitting diode unit connected in series with each other, the first light-emitting diode unit 311 and the second light-emitting unit 312 are internally illuminated. The pole system may be first connected in series, then connected in a horse, or connected in parallel, and then connected in series. The central control unit i33 includes a switching unit 331 and a control unit 332. The technology switches the early 331 and the second LED The unit 312 is electrically connected to the unit 312. The control unit 332 is connected to the switching unit 331 and the stroking circuit 电201037213, and controls the unit 332 and receives the control signal Sc generated by the detecting circuit 32. In implementation, the switching unit is Contains bipolar transistor (b factory gate or field effect transistor (ΡΈΤ) In the embodiment, the control unit 332 determines whether the control signal is less than a preset value, and the control unit 332 controls the switching unit 331 according to the determination result to cause the switching unit 331 to operate in the on or off state. • The control circuit 33 will turn off or turn on the first LED unit 312 according to the control signal &, and cause the LED module to operate at a preset current value. Yes, in the present embodiment, the first light emitting diode unit is not controlled by the control unit 33, and the Russian circuit 32 is an instant circuit. Here, the so-called uncontrolled system is the first light emitting diode. The illumination of the polar body unit 3 ιι is controlled by the power source, and the actuation of the control circuit % will not directly affect the illuminance of the first illuminating diode unit 3 ιι, however, the two are still electrically connected. By the above hardware architecture, the present invention will be able to instantly detect the change of the (four) level of the variable electric f.f V, and change the number of the turned-on light-emitting diodes to make the light-emitting diode extremely difficult. In the default state, and then improve the work Therefore, the lighting device of the present invention is not limited to the power supply unit must provide a stable power supply. In addition, in practical applications, the architecture of the control circuit can be changed according to different needs. In the following, please refer to FIG. 4A and FIG. 4B to illustrate two application architectures of the control circuit. 201037213 As shown in FIG. 4A, for the convenience of description, the LED module has four light-emitting diodes. The body unit is taken as an example. However, it is not limited thereto. The LED module 41A includes four LED units 4H connected in series. The control circuit 43 includes a plurality of switching units 431 and a control unit 432. Each of the switching units 431 is electrically connected to the corresponding light emitting diode unit 411, and each switching unit 431 is connected in parallel with each other. In addition, the control unit 432 is electrically connected to the detecting circuit 42. In practical use, control unit 432 can include a shift register and a comparator. The shift register is electrically connected to each switching unit 431, and the comparator is electrically connected to the shift register and the detecting circuit 42 respectively, and receives the control signal Sc generated by the detecting circuit 42. The control circuit 432 determines whether the control signal Sc is smaller than a preset value by the comparator, and controls each switching unit 431 according to the determination result to respectively turn off or turn on the LED units 411, thereby enabling the LED module to be turned on. 41A operates at a preset current value. Next, referring to Fig. 4B and Fig. 5, a manner of adjusting the number of light emitting diodes when the light emitting device 4B is operated with an alternating voltage will be further described below. In addition, this embodiment is exemplified by a constant current (80 mA) passing through all the light emitting diode units, but it is not limited thereto. In the present embodiment, the variable voltage V is an alternating current voltage as shown in Fig. 5. Among them, the variable voltage V can be divided into four sections from a low pressure to a high voltage. In the first segment R1, the duty cycle of the LED module is 201037213 85%; in the second segment R2, the duty cycle of the LED module is 70%; and in the third segment R3 The working period of the light emitting diode module is 50%; when the fourth section is R4, the working period of the light emitting diode module is 25%. As shown in FIG. 4B, the light-emitting diode module 41B of the light-emitting device 4B includes four light-emitting diode units 411A, 411B, 411C, and 411D connected in series. Among them, the light-emitting diode units 411A, 411B, and 411C are respectively included in four, three, and two light-emitting diodes connected in parallel. The control circuit 43 includes a first switching unit 431A, a second switching unit ® 431B, a third switching unit 431C, and a control unit 432. Each of the switching units 431A to 431C is electrically connected to the corresponding LED units 411A to 411D, and the switching units 431A to 431C are connected in series with each other. The detecting circuit 42 is electrically connected to the control unit 432 and detects a change in the voltage level of the variable voltage V. When the voltage level of the variable voltage V is located in the first segment R1, the LED unit 411A emits light according to the received variability voltage V; when the voltage level of the variable voltage V is located in the second region In the segment R2, the detecting circuit 42 outputs a control signal to the control unit 432 to 'cut off the first switching unit 431A, and turn on the light emitting diode units 411A, 411B; when the voltage level of the variable voltage V is at the third position In the segment R3, the detecting circuit 42 outputs a control signal to the control unit 432 to turn off the first switching unit 431A and the second switching unit 431B, and turn on the light emitting diode units 411A to 411C; when the voltage of the variable voltage V is accurate When the bit is located in the fourth segment R4, the detecting circuit 42 outputs a control signal to the control unit 432, and the first switching unit 431A, the second switching unit 431B, and the third switching unit 431C are turned off at 201037213, and the LED unit is turned on. 411A~411D. In other words, when the voltage level is in the first segment R1, the current flowing through each of the LEDs of the LED unit 411A is 20 mA; when the voltage level is in the second segment R2, the flow is newly added. The current of each of the light-emitting diodes of the diode unit 411B is 26.6 mA; when the voltage level is in the third section R3, the current of each of the light-emitting diodes flowing through the light-emitting diode unit 411C is 40 mA; When the voltage level is in the fourth section R4, the current of the light-emitting diode that flows through the light-emitting diode unit 411D is newly increased to 80 mA. At this time, the output power ratio of each of the light emitting diode units 411A to 411D will be 17: 18.62 : 20 : 20 in one cycle time. In practice, a capacitor can be added to the circuit of the illuminating device to extend the working period of the first segment and the second segment to 100% and 75%, thereby forming an output power ratio of each of the illuminating diode units. 20 : 20 : 20 : 20 ° By the hardware structure shown in FIG. 4B, the present invention can make each light-emitting diode unit by changing the number of light-emitting diodes that are turned on in each light-emitting diode unit. Have similar or identical output power. In addition, it is to be noted that the present invention does not limit the number of light-emitting diodes included in each of the light-emitting diode units, and the manner in which the light-emitting diodes in each of the light-emitting diode units are connected. In addition, the illuminating device of the present invention can be a backlight or a illuminating device, and can be applied to the field of mobile communications, the field of lighting for transportation vehicles, and general lighting applications. According to 10, 2010, 372, and vr', the light-emitting device according to the present invention adjusts the number of light-emitting diodes that are turned on in the light-emitting diode module by controlling the electric power. With the Xidan W phase car, the test can clearly operate the home light-pole module in a preset state by changing the number of the light-emitting diodes that are turned on, thereby enabling the power supply to be operated by a variable power source. (4) At the same time, it is possible to avoid the power loss of the L-element U & 〇 The above description is for illustrative purposes only and not as a limitation. Any equivalent modifications or changes to the spirits and stipulations of this document shall be included in the scope of the appended patent application. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a schematic view of a light-emitting device of a conventional constant voltage control; FIG. 1B is a schematic view of a light-emitting device of a conventional constant current control; FIG. 2 is a schematic view of a light-emitting device according to a preferred embodiment of the present invention; 3 is a schematic diagram of a light-emitting device according to a preferred embodiment of the present invention; FIG. 4A to FIG. 4B are schematic diagrams showing different variations of the light-emitting device of the present embodiment; and FIG. Explanation of voltage [Main component symbol description] ΙΑ, 1B, 2, 3, 4A, 4B: illuminating device 11, 21, 31, 41A, 41B: LED module 11 201037213 12: Capacitor 13: Resistor 14: Constant voltage source 15: constant current source 16: detection unit 211, 411, 411A, 411B, 411C, 411D: light-emitting diode unit 22, 32, 42: detection circuit 23, 33, 43: control circuit 311: First light-emitting diode unit 312 : second light-emitting diode unit 331 : switching unit 332 , 432 : control unit 431 : switching unit 431A : first switching unit 431B · second switching unit 431C : third switching unit R1 : The first section R2: the first Section R3: third section R4: the fourth section S c: control signals V: variable voltage 12