1255376 修正 曰 --案號.93108639_年 ^ 五、發明說明（1) 【發明所屬之技術領域】 哭本發明係有關於一種背光單元，特別是適用於顯示 =，用以提供均勻光源至顯示器之面板。本發明係利用具 有^流鏡特性之電路以提供複數相等之電流以驅動複數發 光單元，使複數發光單元之亮度相等。 【先前技術】 、卩远著半導體製造以及平面顯示器技術之進步，習知如 ，晶顯示器（Liquid Crystal DiSplay，LCD )等顯示裝 1 已可應用於各種不同之電子產品，例如行動電話 、（Cellular Telephone)、數位相機（Digital Camera) 以及個人數位助理（Personal Digital Assistant， PDA )等資訊產品，甚至是飛航儀器顯示系統都採用了 技術。這類的產品通常會在不同明暗程度的環境中使用， 為了讓顯不在LCD螢幕上的影像擁有更佳的能見度，LCD顯 不裝置需要一個背光（backl ight)源，也就是一位sLCD面 板背面的光源。 第1圖係表示習知LCD之背光單元1，其中發光單元 T10、T11…Tin為LCD之背光源。如第}圖所示，發光單元 T10、Τ11···Τ1η接收由驅動器;[〇輸出之驅動電壓v〇uti〇， 且母一發光單元具有複數彼此串聯的發光二極體（1丨❹卜 emitting diode，LED )。回授電阻RFl〇、RFU ..·Κ]Πη * 別躺接於發光單元ΤΙ 0、ΤΙ 1…ΤΙ η與接地電源GND之間。此 外，驅動裔1 〇分別監控節點N1 〇、j\j 1 ;n 1 n之電壓位準， 而進一步輸出對應之驅動電壓V〇utl0至發光單元Τ1〇、1255376 曰 - - 案 案 案 93 93 93 93 93 93 93 93 93 93 93 93 93 93 、 、 、 、 、 、 、 、 、 、 、 、 、 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本The panel. The present invention utilizes a circuit having the characteristics of a flow mirror to provide a plurality of equal currents to drive the plurality of light emitting units to equalize the brightness of the plurality of light emitting units. [Prior Art] With the advancement of semiconductor manufacturing and flat panel display technology, conventional display devices such as Liquid Crystal DiSplay (LCD) can be applied to various electronic products, such as mobile phones, (Cellular). Information products such as Telephone), Digital Camera, and Personal Digital Assistant (PDA), and even the navigation instrument display system use technology. This type of product is usually used in different levels of light and darkness. In order to provide better visibility of images that are not on the LCD screen, the LCD display device requires a backlight source, which is the back of an sLCD panel. Light source. Fig. 1 shows a backlight unit 1 of a conventional LCD in which light-emitting units T10, T11, ... Tin are backlights of an LCD. As shown in the figure, the light-emitting unit T10, Τ11···Τ1η receives the driver; [〇 output driving voltage v〇uti〇, and the mother-emitting unit has a plurality of light-emitting diodes connected in series with each other (1丨❹b) Emitter diode, LED ). The feedback resistor RF1〇, RFU ..·Κ]Πη * is not lying between the light-emitting unit ΤΙ 0, ΤΙ 1...ΤΙ η and the ground power GND. In addition, the driver 1 〇 monitors the voltage levels of the nodes N1 〇, j\j 1 ; n 1 n respectively, and further outputs the corresponding driving voltage V〇utl0 to the light-emitting unit Τ1〇,
0632-l〇259TWf 1(4.5) * AU0305054 .* Yvonne.pt 第5頁 案號 931086390632-l〇259TWf 1(4.5) * AU0305054 .* Yvonne.pt Page 5 Case No. 93108639
修正 1255376 五、發明說明（2) m -"Tin。 由於驅動電壓VoutlO施加於發光單元tiq、 ΤΙ 1 .4111，故產生分別流經發光單元τι 〇、Τι 1 "·Τ1 n之電 流II 0、I 11…I 1 η。而實際操作上，背光單元J之發光/一 T1 0、T 1 1 "·τ 1 η之複數LED内阻不盡相同，且回授電阻一 RF10、RF11…RFln具有誤差，導致電流π〇、ιη···ΐΐη 相等。因此每一發光單元之LED亮度不一致，進而使背光 單元所產生之亮度不均勻，影響顯示畫面。 【發明内容】 有鑑於此，為了解決上述問題，本發明主要目 ?供：種背光單元、，適用於顯示器、，係利用電流鏡特性‘ 提供稷數相等之電流以驅動複數發光單元，使複數發 元之亮度相等。 又尤早 為獲致上述之目的，本發明提出一種背光單元，包括 驅動器、複數發光單元以及電流鏡單m = 單兀具有彼此串接之複數笋夯- _ 钐先 ^ ^ ^ 、九—極體。驅動器係根攄Θ沪 電壓而輸出對應之驅動電壓。 嚴杈 輸出回授電壓至驅動器，並IJ tL Ϊ 收驅動電壓且 之=驅動電流以分別驅動發光單元。此外驅動哭根據= 授電壓而改變輸出之驅動電壓，進而改變參考根據 下文特舉-較佳實施例，：配；被和優點能更明顯易懂’ 下· 入兄曰所附圖式，作詳細說明如 【實施方式】Amendment 1255376 V. Description of invention (2) m -"Tin. Since the driving voltage Vout10 is applied to the light-emitting units tiq, ΤΙ1. 4111, currents II 0, I 11 ... I 1 η flowing through the light-emitting units τι 〇, Τι 1 "·Τ1 n, respectively, are generated. In actual operation, the internal resistance of the LED of the backlight unit J/T1 0, T 1 1 "·τ 1 η is not the same, and the feedback resistors RF10, RF11...RFln have errors, resulting in a current π〇 , ιη···ΐΐη is equal. Therefore, the brightness of the LEDs of each of the light-emitting units is inconsistent, and the brightness generated by the backlight unit is uneven, which affects the display screen. SUMMARY OF THE INVENTION In view of the above, in order to solve the above problems, the present invention mainly provides a backlight unit, which is suitable for a display, and uses a current mirror characteristic to provide a current with an equal number of turns to drive a plurality of light-emitting units to make a plurality of light-emitting units. The brightness of the hair elements is equal. In order to achieve the above object, the present invention provides a backlight unit including a driver, a plurality of light-emitting units, and a current mirror. The single m=single-turn has a plurality of tantalum-- 钐 ^ ^ ^ ^, nine-pole body . The driver outputs the corresponding driving voltage based on the voltage of the Shanghai. Strictly output the feedback voltage to the driver, and IJ tL Ϊ the drive voltage and = drive current to drive the illumination unit separately. In addition, driving the crying changes the driving voltage of the output according to the voltage being applied, and then changing the reference according to the following specific description - the preferred embodiment: the matching; the advantage and the advantage can be more clearly understood 'under the brother-in-law Detailed description as in [Embodiment]
1255376 五、發明說明（3) 貫施例： 第2圖係表示本發明實施例之背光單元2方塊圖，其 中’母一發光單元具有衩數串聯之發光二極體（light-emitting diode， LED) ， 本發明 係以三個發光 單元為 例。如圖所示，驅動器2 0提供驅動電壓v〇ut20至電流鏡單 兀2 1，且使電流鏡單元2 1產生一個參考電流。接著，電流 鏡單元2 1依據電流源而分別提供驅動電流I 2 〇、I 2 1、I 2 2 至發光單元T20、T12、T22，以驅動發光單元T20、T21、 T22，其中驅動電流120、121、122之電流值彼此相等。同 時，電流鏡單元21輸出回授電壓Vi至驅動器20，使驅動器 根據回授電壓Vf的大小而改變驅動電壓。 第3圖係表示本發明實施例之電路圖。在本實施例 中，每一發光單元内以具有四個彼此串聯之LEI)為例。發1255376 V. DESCRIPTION OF THE INVENTION (3) Example: FIG. 2 is a block diagram showing a backlight unit 2 according to an embodiment of the present invention, in which a 'mother-light emitting unit has a light-emitting diode (LED) connected in series. The invention is exemplified by three light-emitting units. As shown, the driver 20 supplies a drive voltage v〇ut20 to the current mirror unit 1,2 1, and causes the current mirror unit 2 1 to generate a reference current. Next, the current mirror unit 21 provides driving currents I 2 〇, I 2 1 , I 2 2 to the light emitting units T20, T12, T22 according to the current source to drive the light emitting units T20, T21, T22, wherein the driving current 120, The current values of 121 and 122 are equal to each other. At the same time, the current mirror unit 21 outputs the feedback voltage Vi to the driver 20, causing the driver to change the driving voltage in accordance with the magnitude of the feedback voltage Vf. Figure 3 is a circuit diagram showing an embodiment of the present invention. In the present embodiment, each of the light-emitting units has an example of having four LEIs connected in series with each other. hair
光單元T20具有LED D01、D02 'D03及D04 ;發光單元T21具 有LED Dll、D12、D13及D14 ;以及發光單元T22具有LED D 2 1、D 2 2、D 2 3及D 2 4。如圖所示，電流鏡單元2 1包括電流 源CS、電晶體Qcs、Q20、Q21及Q22、以及電阻、R20、 R2 1及R22，而本發明實施例之電晶體以具有相同特性之雙 極電晶體（BJT)為例。電晶體Qcs之基極與集極彼此連^ 並耦接至電流源CS，而電晶體QCS之射極與電阻RF2耦接於 節點N20。電晶體Q20之基極與QCS之基極彼此耦接，電晶 體Q20之集極耦接於發光單元了2〇，且電晶體Q2〇之射極透 過電阻R20耦接接地電源GND。同樣地，電晶體Qg 1之夷極 與Qcs之基極彼此耦接，電晶體q21之集極耦接於發光ι單元 第7頁 0632-10259TWfl(4.5) ； AU0305054 ； Yvonne.ptc 1255376 棄"ιη_ , __案號 93108639 __年 月_g_修正__ 五、發明說明（4) T2 1，且電晶體Q2 1之射極透過電阻R2 1耦接接地電源GND。 其中，電阻R20、R21及R22具有保護作用，係避免電晶體 Q20、Q21及Q22之射極直接耦接接地電源GND，造成電晶體 之集-射極電壓過大，導致電晶體Q20、Q21及Q22損壞。 由於電流源CS接收驅動電壓V〇ut20，故電流源CS可利 用驅動電壓Vout 20與電阻RCS之比例來產生參考電流if。 當驅動器20輸出驅動電壓Vout 20並施加於電阻RCS時，產 生參考電流I f以提供至電晶體Qcs。由於參考電流I f及電 晶體Q c s、 Q 2 0、Q 2 1及Q 2 2形成電流鏡電路，故利用電流 鏡性的特性，可使驅動電流I 2 0、I 2 1、I 2 2彼此相等，並 與參考電流I f成比例。本發明實施例中，由於電晶體Q c S 及Q 2 0、Q 2 1、Q 2 2特性相同，透過電流鏡特性可得知，電 流I 2 0、I 2 1及I 2 2與參考電流I f相等。 另外，在本發明之實施例中，每一發光單元T2 0、丁2 1 、T 2 2之複數串聯之L E D係以位置彼此交錯方式依序排列。 如第4圖所示，LED D01、D11及D21之位置彼此相鄰，LED D02、D12及D22之位置彼此相鄰，LED D03、D13及D23之位 置彼此相鄰，且L E D D 0 4、D 1 4及D 2 4之位置彼此相鄰。由 於為了方便說明本發明實施例之電路操作，第3圖所示之 發光單元T20、T21、T22之複數串聯之LED係以並排方式表 示〇 本發明之實施例，係利用複數特性相同之電晶體及電 流源所組成之電流鏡之特性，以使流經複數發光單元之複 數驅動電流彼此相等，進而使複數發光單元内之LED之亮The light unit T20 has LEDs D01, D02 'D03 and D04; the light-emitting unit T21 has LEDs D11, D12, D13 and D14; and the light-emitting unit T22 has LEDs D 2 1 , D 2 2, D 2 3 and D 2 4 . As shown, the current mirror unit 21 includes a current source CS, transistors Qcs, Q20, Q21, and Q22, and resistors, R20, R2, and R22, while the transistor of the embodiment of the present invention has bipolar characteristics having the same characteristics. A transistor (BJT) is taken as an example. The base and the collector of the transistor Qcs are connected to each other and coupled to the current source CS, and the emitter of the transistor QCS is coupled to the resistor RF2 at the node N20. The base of the transistor Q20 and the base of the QCS are coupled to each other. The collector of the transistor Q20 is coupled to the light-emitting unit by 2 turns, and the emitter of the transistor Q2 is coupled to the ground power source GND through the resistor R20. Similarly, the anode of the transistor Qg 1 and the base of the Qcs are coupled to each other, and the collector of the transistor q21 is coupled to the illuminating unit 7 page 0632-10259 TWfl (4.5); AU0305054; Yvonne.ptc 1255376 discards " Ιη_ , __ Case No. 93108639 __年月_g_修正__ V. Description of invention (4) T2 1, and the emitter of transistor Q2 1 is coupled to ground power GND through resistor R2 1 . Among them, the resistors R20, R21 and R22 have a protective function, which prevents the emitters of the transistors Q20, Q21 and Q22 from being directly coupled to the grounding power source GND, causing the collector-emitter voltage of the transistor to be too large, resulting in transistors Q20, Q21 and Q22. damage. Since the current source CS receives the driving voltage V〇ut20, the current source CS can use the ratio of the driving voltage Vout 20 to the resistance RCS to generate the reference current if. When the driver 20 outputs the driving voltage Vout 20 and applies it to the resistor RCS, a reference current If is generated to be supplied to the transistor Qcs. Since the reference current I f and the transistors Q cs, Q 2 0, Q 2 1 and Q 2 2 form a current mirror circuit, the currents of the current can be used to drive the currents I 2 0, I 2 1 , I 2 2 They are equal to each other and are proportional to the reference current I f . In the embodiment of the present invention, since the characteristics of the transistors Q c S and Q 2 0, Q 2 1 and Q 2 2 are the same, the current I 2 0, I 2 1 and I 2 2 and the reference current can be known by the characteristics of the current mirror. I f is equal. In addition, in the embodiment of the present invention, the L E D of the plurality of light-emitting units T20, D2, and T22 are sequentially arranged in a staggered manner. As shown in Fig. 4, the positions of the LEDs D01, D11 and D21 are adjacent to each other, the positions of the LEDs D02, D12 and D22 are adjacent to each other, and the positions of the LEDs D03, D13 and D23 are adjacent to each other, and the LEDD 0 4, D 1 The positions of 4 and D 2 4 are adjacent to each other. In order to facilitate the description of the circuit operation of the embodiment of the present invention, the plurality of LEDs of the light-emitting units T20, T21, and T22 shown in FIG. 3 are shown in a side-by-side manner. The embodiment of the present invention utilizes a transistor having the same complex characteristics. And a current mirror composed of a current source, so that the plurality of driving currents flowing through the plurality of light-emitting units are equal to each other, thereby causing the LEDs in the plurality of light-emitting units to be bright
0632-10259TWfl(4.5) · AU0305054 ； Yvonne.ptc 第8頁 1255376 案號 93108639_年月日__ 五、發明說明（5) 度等亮，以避免LED内阻不同而造成LED之亮度不一致。並 且，由於複數發光單元内之複數串聯之LED係以位置彼此 交錯方式依序排列，因此當任一發光單元内之任一LED損 壞而導致對應之發光單元失效時，不會造成L C D螢幕之特 定部份之背光亮度較暗，而是整體背光亮度均勻變暗，而 達到較佳的顯示效果。 在此須注意的是，本發明之實施例中，係以三個背光 單元，以及每一背光單元具有四個LED為例，在實際的應 用上，係不以此數量為限。另外，本發明之電晶體之種類 也不以雙極電晶體（BJT )為限。 本發明雖以較佳實施例揭露如上，然其並非用以限定 本發明的範圍，任何熟習此項技藝者，在不脫離本發明之 精神和範圍内，當可做些許的更動與潤飾，因此本發明之 保護範圍當視後附之申請專利範圍所界定者為準。0632-10259TWfl(4.5) · AU0305054 ; Yvonne.ptc Page 8 1255376 Case No. 93108639_年月日日__ V. Invention description (5) The brightness is equal to avoid the LED internal brightness is different and the brightness of the LED is inconsistent. Moreover, since the plurality of LEDs connected in series in the plurality of light-emitting units are sequentially arranged in a staggered manner, when any one of the LEDs in any of the light-emitting units is damaged and the corresponding light-emitting unit fails, the LCD screen is not specified. Part of the backlight is darker, but the overall backlight brightness is evenly dimmed to achieve a better display. It should be noted that in the embodiment of the present invention, three backlight units are used, and each of the backlight units has four LEDs as an example, and the actual application is not limited to this number. Further, the type of the transistor of the present invention is not limited to a bipolar transistor (BJT). The present invention has been described above with reference to the preferred embodiments thereof, and is not intended to limit the scope of the present invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.
0632-10259TWfl(4.5) ； AU0305054 ； Yvonne.ptc 第9頁 1255376案號93108639_年月日 修正_ 圖式簡單說明 第1圖表示習知LCD之背光單元。 第2圖表示本發明實施例之背光單元之方塊圖。 第3圖表示本發明實施例之背光單元之電路圖。 第4圖表示本發明實施例中，複數發光單元之複數LED 排列方式。 【符號說明】 1〜背光單元； 1 0〜驅動器； T10、ΤΙ 1…Tin〜發光單元； RF 1 0、RF11 ".RFln〜回授電阻； η〇、Ν：Π "·Ν1η〜節點； GND〜接地電源； 2〜背光單元； 2 0〜驅動器； 2 1〜電流鏡早元， Τ20、Τ21、Τ22〜發光單元； DO 1、D02、D03、D04 Dll、D12、D13、D14、D21、 D22、D23、D24〜LED ; CS〜電流源；0632-10259TWfl(4.5) ; AU0305054 ; Yvonne.ptc Page 9 1255376 Case No. 93108639_年月月日 Revision _ Schematic description of the drawing Figure 1 shows the backlight unit of the conventional LCD. Fig. 2 is a block diagram showing a backlight unit of an embodiment of the present invention. Fig. 3 is a circuit diagram showing a backlight unit of an embodiment of the present invention. Figure 4 is a diagram showing the arrangement of a plurality of LEDs of a plurality of light-emitting units in an embodiment of the present invention. [Description of symbols] 1~ backlight unit; 1 0~ driver; T10, ΤΙ 1...Tin~ illuminating unit; RF 1 0, RF11 ".RFln~ feedback resistor; η〇, Ν:Π "·Ν1η~ node ; GND ~ ground power; 2 ~ backlight unit; 2 0 ~ driver; 2 1 ~ current mirror early element, Τ 20, Τ 21, Τ 22 ~ illuminating unit; DO 1, D02, D03, D04 Dll, D12, D13, D14, D21 , D22, D23, D24~LED; CS~ current source;
Qcs、Q20、Q21 、Q22〜電晶體； RF2、R20、R21、R22〜電阻。Qcs, Q20, Q21, Q22~ transistor; RF2, R20, R21, R22~ resistor.
0632-10259TWfl(4.5) ； AU0305054 ； Yvonne.ptc 第10頁0632-10259TWfl(4.5) ; AU0305054 ; Yvonne.ptc Page 10