201013269 九、發明說明： 【發明所屬之技術領域】 特別是有關於一 本發明是有關於一種調光控制電路， 種應用於背光模組之調光控制電路。 【先前技術】 由於光電科技的蓬勃發展’生活中越來越多機會接觸 -到各式各樣的通訊或電子產品’例如：個人數位助理 ® (Personal digital assistant ; PDA)、行動電話、筆記型電腦、 桌上型顯示器、車用顯示器等等。其中，顯示裝置為這些 通訊或電子產品所應共通具備之裝置，因此顯示裝置的優 劣攸關著這些通訊或電子產品的優劣。所以顯示裝置能具 備高晝質、體積小、重量輕、低驅動電壓、與低消耗功率 等優點是亟於努力之目標。 一般而言，目前的顯示器皆配備有背光模組來提供背 光，而背光模組則配備有調光控制電路，以控制背光源的 ❹ 亮度。 請參照第1圖，其係繪示習知背光模組1〇的功能方塊 示意圖。背光模組i 0包含光源i 2、換流器（inverter)丨4、脈 衝寬度調變模組（PWMmodule)16、電流偵測裝置18和調光 控制電路20,其中電流偵測裝置18係用以偵測光源12的 工作電流。在背光模組1〇中’光源12的亮度係由換流器 14所控制’換流器η提供的電流越大，光源12的亮度就 越強，反之，右換流器14提供的電流越小，光源12的亮 度就越小^光控制電路2G係用以控制換流器14所輸出 201013269 之電流大小。調光控制電路20係根據使用者輸入之外部訊 號Sr和電流偵測裝置18所回授之電流偵測訊號心號來輸 出免度控制訊號Sc，以利用亮度控制訊號Sc來控制換流器 14所輸出之電流。脈衝寬度調變模組16係電性連接於調光 控制電路20和換流器14之間，用以將亮度控制訊號心調 變成脈衝訊號’並輸入至換流器14。 ❹ ❹ 請參照第2圖，其係繪示習知調光控制電路2〇的電路 結構示意圖》調光控制電路2〇包含比較器22、電阻以、 26、28和30。比較器22之正端係用以接收使用者所輸入 之外部訊號sr。外部訊號Sr輸入至比較器22後，比較器 22便會計算外部訊號&與參考電壓％之差值，並將此差 值輸出至電阻28。電阻3G係電性連接至電流偵測裝置18, 以接收電流㉝測訊號Sf’並利用電阻28來將電流制訊號 sf與比較器22輸出之差值耦合成亮度控制訊號I。 由上述說明可知，調光控制電路2Q可使亮度控制訊號 \之值隨著使用者輸入之外部訊號&之值而線性變化，以 ”變光源12之冗度。一般而言，使用者只能由三種外部訊 Μ值中擇-輸出，即0伏特、1.6伏特和3.3伏特，A中 U伏特係對應至標準亮度，Q伏特係對應至較低的亮度， 而3.3伏特係對應至較高的亮度。㈣，調光控制電路2〇 :使儿度控制訊號Se之值隨著外部訊號&之值而呈線性變 ^但在外部訊號Sj變化為有限的情況下，亮度控制訊 解柄Λ值亦為有限’換句話說，光源12所能呈現之亮度的 解析度也相對較小，而無法滿足❹者的需求。 因此’需要-種可調整外部訊號&對應之電流值的調 201013269 光控制電路，以確保光源之亮度的解析度可滿足使用者之 需求。 【發明内容】 因此’本發明之一方面係在提供一種調光控制電路， 其可根據使用者之需求來調整外部訊號所對應之電流值。 本發明之另一方面係在提供一種背光模組，其可根據 使用者之需求來調整外部訊號所對應之電流值。 ❹ 本發明之再一方面係在提供一種顯示器，其可根據使 用者之需求來調整外部訊號所對應之電流值。 根據本發明之一實施例，此調光控制電路包含電流切 換開關、至少一電阻、電壓切換開關、準位判斷電路和比 較器。電流切換開關係用以選取一電流。電阻係電性連接 至電流切換開關，以依據該電流來產生一對應電壓值，電 壓切換開關係用以接收該對應電壓值並輸出一參考電壓。 準位判斷電路係依據外部輸入電壓之大小來控制電流切換 φ 開關和電壓切換開關。比較器係用以接收一回授電壓及該 參考電壓’並輸出一亮度控制訊號。 根據本發明之一實施例，此背光模組包含上述之調光 控制電路、光源和換流器，其中換流器係電性連接於光源 和調光控制電路之間，以根據亮度控制訊號來控制輸出至 光源之電流大小。 根據本發明之一實施例，此顯示器包含上述之背光模 組和一顯示面板，其中顯示面板係設置於背光模組上，用 以接收背光模組所提供之光線來顯示影像。 201013269 【實施方式】 請參照第3圖，其係緣示根據本發明一實施例之調光 控制電路100的電路結構示意圖。調光控制電路⑽包含 電流源110、電流源120、電流切換開關13〇、電阻ri、電 壓切換開關150、準位判斷電路16〇和比較器17〇。電流切 換開關130係電性連接至電流源11〇和電流源12〇，以輸出 第一電流I!或第二電流匕，其中電流源11〇係用以輸出第 一電流I!，而電流源120係用以輸出第二電流l2。電阻幻 係電性連接至電流切換開關130,以接收電流切換開關13〇201013269 IX. Description of the invention: [Technical field to which the invention pertains] In particular, the invention relates to a dimming control circuit, which is applied to a dimming control circuit of a backlight module. [Prior Art] Due to the booming of optoelectronic technology, 'more and more opportunities to contact in life-to a wide variety of communication or electronic products' such as Personal Digital Assistant (PDA), mobile phones, notebook computers , desktop monitors, car monitors, etc. Among them, the display device is a device commonly used for these communication or electronic products, and therefore the advantages and disadvantages of the display device are related to the advantages and disadvantages of these communication or electronic products. Therefore, the display device can have the advantages of high quality, small size, light weight, low driving voltage, and low power consumption. In general, current displays are equipped with backlight modules to provide backlighting, while backlight modules are equipped with dimming control circuitry to control the brightness of the backlight. Please refer to FIG. 1 , which is a functional block diagram of a conventional backlight module 1 . The backlight module i 0 includes a light source i 2, an inverter 丨 4, a pulse width modulation module (PWM module) 16, a current detecting device 18, and a dimming control circuit 20, wherein the current detecting device 18 is used. To detect the operating current of the light source 12. In the backlight module 1 ' 'the brightness of the light source 12 is controlled by the inverter 14 'the greater the current supplied by the inverter η, the stronger the brightness of the light source 12, and vice versa, the higher the current supplied by the right converter 14 Small, the brightness of the light source 12 is smaller. The light control circuit 2G is used to control the current of the current output of the converter 14201013269. The dimming control circuit 20 outputs the degree-free control signal Sc according to the external signal Sr input by the user and the current detection signal heart value fed back by the current detecting device 18 to control the inverter 14 by using the brightness control signal Sc. The current output. The pulse width modulation module 16 is electrically connected between the dimming control circuit 20 and the inverter 14 for converting the brightness control signal into a pulse signal and inputting it to the inverter 14. ❹ ❹ Please refer to FIG. 2, which is a schematic diagram showing the circuit structure of the conventional dimming control circuit 2A. The dimming control circuit 2 includes a comparator 22, resistors 26, 28, and 30. The positive terminal of the comparator 22 is for receiving an external signal sr input by the user. After the external signal Sr is input to the comparator 22, the comparator 22 calculates the difference between the external signal & and the reference voltage %, and outputs the difference to the resistor 28. The resistor 3G is electrically connected to the current detecting device 18 to receive the current 33 signal Sf' and the resistor 28 is used to couple the difference between the current signal sf and the output of the comparator 22 into the brightness control signal I. As can be seen from the above description, the dimming control circuit 2Q can linearly change the value of the brightness control signal \ according to the value of the external signal & input by the user, to "change the redundancy of the light source 12. Generally speaking, the user only Can be selected from three external signal values - 0 volts, 1.6 volts and 3.3 volts, U volts in A corresponds to standard brightness, Q volts corresponds to lower brightness, and 3.3 volts corresponds to higher (4), dimming control circuit 2〇: the value of the child control signal Se is linearly changed according to the value of the external signal & but in the case where the external signal Sj is limited, the brightness control handle The devaluation is also limited. In other words, the resolution of the brightness that the light source 12 can exhibit is relatively small, and cannot meet the needs of the latter. Therefore, it is necessary to adjust the external signal & 201013269 Light control circuit to ensure the resolution of the brightness of the light source can meet the needs of the user. [Invention] Therefore, one aspect of the present invention provides a dimming control circuit that can be adjusted according to the needs of the user. The current value corresponding to the partial signal. Another aspect of the present invention provides a backlight module that can adjust the current value corresponding to the external signal according to the needs of the user. 再 A further aspect of the present invention provides a a display, which can adjust the current value corresponding to the external signal according to the needs of the user. According to an embodiment of the invention, the dimming control circuit comprises a current switching switch, at least one resistor, a voltage switching switch, a level determining circuit, and The current switching relationship is used to select a current. The resistance is electrically connected to the current switching switch to generate a corresponding voltage value according to the current, and the voltage switching relationship is to receive the corresponding voltage value and output a reference voltage. The level determining circuit controls the current switching φ switch and the voltage switching switch according to the magnitude of the external input voltage. The comparator is configured to receive a feedback voltage and the reference voltage 'and output a brightness control signal. According to the invention In an embodiment, the backlight module includes the dimming control circuit, the light source, and the inverter, wherein the commutation Electrically connected between the light source and the dimming control circuit to control the magnitude of the current output to the light source according to the brightness control signal. According to an embodiment of the invention, the display comprises the backlight module and a display panel, wherein The display panel is disposed on the backlight module to receive the light provided by the backlight module to display the image. 201013269 [Embodiment] Please refer to FIG. 3, which illustrates a dimming control circuit according to an embodiment of the present invention. The circuit configuration diagram of 100. The dimming control circuit (10) includes a current source 110, a current source 120, a current switching switch 13A, a resistor ri, a voltage switching switch 150, a level determining circuit 16A, and a comparator 17A. The current switching switch 130 The system is electrically connected to the current source 11 〇 and the current source 12 〇 to output a first current I! or a second current 匕, wherein the current source 11 is used to output the first current I!, and the current source 120 is used to The second current l2 is output. The resistor is electrically connected to the current switch 130 to receive the current switch 13〇
所輸出之第一電流或第二電流，其中電阻R1之端點Rla 係電性連接至參考電壓Vg，而端點Rib係電性連接至電流 切換開關130。電壓切換開關150具有電壓輸入端15〇a、 150b以及電壓輸出端i5〇c。電壓輸入端15〇a係電性連接 至電阻R1之端點Rib，電壓輸入端i5〇b係電性連接至參 考電壓Vr，以從電壓輸出端i5〇c輸出參考電壓Vr或端點 Rib之電壓。比較器170之負端係電性連接至電壓切換開 關150之電壓輸出端150c，而正端則被輸入一回授訊號sf， 此回授訊號Sf可例如為光源之電流回授訊號。準位判斷電 路160係用以判斷使用者輸入之外部訊號Sr的大小，以決 定電流切換開關130和電壓切換開關150的切換狀態。在 以下的敘述中，將會說明調光控制電路1〇〇是如何調整其 輸出之亮度控制訊號Sc。 由以上的電路連接關係可知，當定電流切換開關130 輸出第一電流L時，電阻R1之端點R1b會出現電壓位準 8 201013269The first current or the second current is output, wherein the end point Rla of the resistor R1 is electrically connected to the reference voltage Vg, and the terminal Rib is electrically connected to the current switching switch 130. The voltage switch 150 has voltage input terminals 15a, 150b and a voltage output terminal i5〇c. The voltage input terminal 15〇a is electrically connected to the end point Rib of the resistor R1, and the voltage input terminal i5〇b is electrically connected to the reference voltage Vr to output the reference voltage Vr or the end point Rib from the voltage output terminal i5〇c. Voltage. The negative terminal of the comparator 170 is electrically connected to the voltage output terminal 150c of the voltage switching switch 150, and the positive terminal is input with a feedback signal sf. The feedback signal Sf can be, for example, a current feedback signal of the light source. The level determining circuit 160 is configured to determine the magnitude of the external signal Sr input by the user to determine the switching state of the current switching switch 130 and the voltage switching switch 150. In the following description, how the dimming control circuit 1 调整 adjusts the output of the brightness control signal Sc will be explained. It can be seen from the above circuit connection relationship that when the constant current switching switch 130 outputs the first current L, the voltage level of the end point R1b of the resistor R1 8 201013269
Vmin ’而當電流切換開關130輸出第二電流l2時，端點尺化 會出現電壓位準Vlnax，其中Vmin= Ii#R1+Vg，而電壓位準 Vmax= IpRl+Vg。若設定第一電流L之值小於第一電流h 之值，則電壓位準v_之值會小於電壓位準Vmax之值。接2 著，將參考電壓vr之值設計成介於電壓位準Vmax*電壓位 準Vrain之間，如此準位判斷電路16〇可根據外部訊號\來 控制電流切換開關130和電壓切換開關15〇的切換狀態， 以使電壓切換開關150輸出參考電壓位準Vmin、Vmax和參 © 考電壓Vr。然後，比較器170則計算電壓切換開關150所 輸出之訊號與回授訊號Sf之間的差值，並根據此差值來輸 出亮度控制訊號Se。 由上述之說明可知，適當地將外部訊號Sr之值對應至 電壓位準Vmin、Vmax和參考電壓Vr，例如：伏特時， 電壓切換開關150輸出電壓位準Vmax ; Sr=16伏特時，電 壓切換開關150輸出參考電壓vr ; Sr=0伏特時，電壓切換 開關150輸出電壓位準Vmin ’如此可使亮度控制訊號Sc隨 0 著外部訊號sr之變化而變化，而且此變化並非是線性變 化。再者，使用者可藉由更換電阻R1的值來輕易地改變電 壓位準vmin* ν_χ之值，使得亮度控制訊號Se之值更具有 彈性。 另外’值的一提的是’由於在積體電路中，電流源的 實現是相當容易的，因此可將電流源11 〇、電流源120、電 流切換開關130、電壓切換開關15〇、準位判斷電路160和 比較器170整合成一個晶片，並將電阻ri外接於此晶片， 如此不但可大幅縮小調光控制電路100的體積，更可依使 9 201013269 用者之需求來隨時變更電阻R1之值。 請參照第4圖’其係緣示根據本發明一實施例之調光 控制電路200的電路結構示意圖》調光控制電路2〇〇係類 似於調光控制電路100 ’但不同之處在於調光控制電路2〇〇 更包含電阻R2，其中電阻R2之一端係電性連接至電阻ri 之端點Rib’而另一端係電性連接至參考電壓vA。在調光 控制電路200中，由於加入了電阻R2，因此可由克希荷夫 定律得到： ❹ I2+(VA_Vmin)/Rl-(Vmin-Vg)/R2=0 ........... (1)When the current switching switch 130 outputs the second current l2, the end level is scaled to a voltage level Vlnax, where Vmin = Ii#R1 + Vg and the voltage level Vmax = IpRl + Vg. If the value of the first current L is set to be smaller than the value of the first current h, the value of the voltage level v_ will be less than the value of the voltage level Vmax. Connected, the value of the reference voltage vr is designed to be between the voltage level Vmax* voltage level Vrain, so that the level determining circuit 16 can control the current switching switch 130 and the voltage switching switch 15 according to the external signal\ The switching state is such that the voltage switching switch 150 outputs the reference voltage levels Vmin, Vmax and the reference voltage Vr. Then, the comparator 170 calculates the difference between the signal outputted by the voltage switch 150 and the feedback signal Sf, and outputs the brightness control signal Se based on the difference. It can be seen from the above description that the value of the external signal Sr is appropriately matched to the voltage levels Vmin, Vmax and the reference voltage Vr, for example, volts, the voltage switching switch 150 outputs the voltage level Vmax; when Sr=16 volts, the voltage is switched The switch 150 outputs the reference voltage vr; when Sr=0 volts, the voltage switching switch 150 outputs the voltage level Vmin' such that the brightness control signal Sc changes with the change of the external signal sr, and the change is not a linear change. Furthermore, the user can easily change the value of the voltage level vmin* ν_χ by replacing the value of the resistor R1, so that the value of the brightness control signal Se is more flexible. In addition, the value of the current value is because the current source is relatively easy to implement, so the current source 11 〇, the current source 120, the current switch 130, the voltage switch 15 〇, the level can be adjusted. The judging circuit 160 and the comparator 170 are integrated into one chip, and the resistor ri is externally connected to the chip, so that the volume of the dimming control circuit 100 can be greatly reduced, and the resistor R1 can be changed at any time according to the needs of the user of 20101313269. value. 4 is a schematic diagram showing the circuit configuration of the dimming control circuit 200 according to an embodiment of the present invention. The dimming control circuit 2 is similar to the dimming control circuit 100' but differs in dimming. The control circuit 2 further includes a resistor R2, wherein one end of the resistor R2 is electrically connected to the end point Rib' of the resistor ri and the other end is electrically connected to the reference voltage vA. In the dimming control circuit 200, since the resistor R2 is added, it can be obtained by Kirchhoff's law: ❹ I2+(VA_Vmin)/Rl-(Vmin-Vg)/R2=0 .......... . (1)
Ii+(VA-Vmax)/Rl-(Vmax-Vg)/R2=0 ......... (2) 由方程式（1)和（2)便可輕易求得Vmin和Vmax之值。在本實 施例中，由於電阻R2的影響’使得電壓位準Vmin和Vmax 彼此的相關性下降’進而增加了電壓位準Vmin和Vmax設計 上的彈性》 〇 請參照第5圖，其係繪示根據本發明一實施例之背光 模組300的功能方塊示意圖。背光模組30〇包含光源31〇、 換流器320、脈衝寬度調變模組（pwMmodule)330、電流偵 測裝置340和調光控制電路350，其中調光控制電路350 可例如為上述之調光控制電路1〇〇或2〇〇。在背光模組300 中’換流器320係電性連接至光源310，以提供電流至光源 310來點亮光源310。脈衝調變模組330係電性連接於調光 控制電路350和換流器320之間，用以將亮度控制訊號sc 調變成脈衝訊號並輸入至換流器320。電流偵測裝置340 201013269 係用以偵測光源3 10的工作電流’並輸出回授訊號sf至調 光控制電路350。 在本實施例中，由於上述之調光控制電路350具有調 光控制電路100或200之優點，因此背光模組300之亮度 可輕易地被調整至使用者所需的亮度。 請參照第6圖，其係繪示根據本發明一實施例之顯示 器400的功能方塊示意圖。顯示器400包含背光模組3〇〇、 顯示面板410、和前框420。背光模組300係用以提供光線 Ο 至顯示面板410，而顯示面板410則設置於背光模組300 上，以利用該光線來顯示晝面。前框420係設置於顯示面 板410上並卡合於背光模組300之外緣上。由於顯示器400 利用背光模組300來提供背光源，因此顯示器400之亮度 可輕易地被調整至使用者所需的亮度。 雖然本發明已以實施例揭露如上，然其並非用以限定 本發明，任何熟習此技藝者，在不脫離本發明之精神和範 圍内’當可作各種之更動與潤飾，因此本發明之保護範圍 Q 當視後附之申請專利範圍所界定者為準。 【圖式簡單說明】 為讓本發明之上述和其他目的、特徵、和優點能更明 顯易僅’上文特舉一較佳實施例，並配合所附圖式，作詳 細說明如下： 第1圖係繪示習知背光模組的功能方塊示意圖。 第2圖係繪示習知調光控制電路的電路結構示意圖。 第3圖係繪示根據本發明一實施例之調光控制電路的 201013269 電路結構示意圖。 $ 4圖係繪示根據本發明-實施例之調光控制電路的 電路結構示意圖。 第5圖係繚示根據本發明-實施例之背光模組的功能 方塊示意圖。 第6圖係縿示根據本發明一實施例之顯示器4〇〇的功 能方塊示意圖。Ii+(VA-Vmax)/Rl-(Vmax-Vg)/R2=0 (2) The values of Vmin and Vmax can be easily obtained from equations (1) and (2). In the present embodiment, the influence of the resistance R2 'degrades the correlation between the voltage levels Vmin and Vmax' and thus the design flexibility of the voltage levels Vmin and Vmax", please refer to Fig. 5, which is shown A functional block diagram of a backlight module 300 according to an embodiment of the invention. The backlight module 30 includes a light source 31A, an inverter 320, a pulse width modulation module (pwMmodule) 330, a current detecting device 340, and a dimming control circuit 350. The dimming control circuit 350 can be, for example, the above-mentioned The light control circuit is 1 or 2 turns. In the backlight module 300, the inverter 320 is electrically connected to the light source 310 to supply current to the light source 310 to illuminate the light source 310. The pulse modulation module 330 is electrically connected between the dimming control circuit 350 and the inverter 320 for adjusting the brightness control signal sc into a pulse signal and inputting it to the inverter 320. The current detecting device 340 201013269 is for detecting the operating current ' of the light source 3 10 and outputting the feedback signal sf to the dimming control circuit 350. In the present embodiment, since the above-described dimming control circuit 350 has the advantages of the dimming control circuit 100 or 200, the brightness of the backlight module 300 can be easily adjusted to the brightness desired by the user. Please refer to FIG. 6, which is a functional block diagram of a display 400 according to an embodiment of the invention. The display 400 includes a backlight module 3A, a display panel 410, and a front frame 420. The backlight module 300 is configured to provide light to the display panel 410, and the display panel 410 is disposed on the backlight module 300 to display the surface by using the light. The front frame 420 is disposed on the display panel 410 and is engaged with the outer edge of the backlight module 300. Since the display 400 utilizes the backlight module 300 to provide a backlight, the brightness of the display 400 can be easily adjusted to the brightness desired by the user. Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and it is to be understood that the invention may be modified and modified in various ways without departing from the spirit and scope of the invention. Scope Q is subject to the definition of the scope of the patent application. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features, and advantages of the present invention will become more apparent from the <RTIgt; The figure shows a functional block diagram of a conventional backlight module. FIG. 2 is a schematic diagram showing the circuit structure of a conventional dimming control circuit. 3 is a schematic diagram showing the structure of a circuit of the 201013269 dimming control circuit according to an embodiment of the invention. The $4 diagram shows a circuit configuration of a dimming control circuit in accordance with an embodiment of the present invention. Figure 5 is a block diagram showing the function of a backlight module in accordance with an embodiment of the present invention. Figure 6 is a block diagram showing the function of a display 4 according to an embodiment of the present invention.
❹ 【主要元件符號說明】 10 :背光模組 14 :換流器 18 :電流偵測裝置 22 :比較器 26 :電阻 30 :電阻 11〇 :電流源 130 :電流切換開關 150a :電壓輸入端 150c :電壓輸出端 170 :比較器 310 :光源 330 :脈衝寬度調變模組 350 :調光控制電路 410 :顯示面板 Sc :亮度控制訊號 12 :光源 16 :脈衝寬度調變模組 20 ·調光控制電路 24 :電阻 28 :電阻 100 :調光控制電路 12〇:電流源 150:電壓切換開關 150b :電壓輸入端 160 :準位判斷電路 300 :背光模組 320 :換流器 340 ·’電流偵測裝置 400 :顯示器 42〇 :前框❹ [Main component symbol description] 10: backlight module 14: inverter 18: current detecting device 22: comparator 26: resistor 30: resistor 11 〇: current source 130: current switching switch 150a: voltage input terminal 150c: Voltage output terminal 170: Comparator 310: Light source 330: Pulse width modulation module 350: Dimming control circuit 410: Display panel Sc: Brightness control signal 12: Light source 16: Pulse width modulation module 20 • Dimming control circuit 24: Resistor 28: Resistor 100: Dimming control circuit 12: Current source 150: Voltage switching switch 150b: Voltage input terminal 160: Level judging circuit 300: Backlight module 320: Inverter 340 · 'Current detecting device 400: Display 42〇: front frame
Sr :外部訊號 12 201013269 sf:偵測訊號 vr:參考電壓 Ij :電流 R1 :電阻 Rib :端點 VA :參考電壓 vg:參考電壓 I2 ·電流 Rla :端點 R2 :電阻Sr : external signal 12 201013269 sf: detection signal vr: reference voltage Ij : current R1 : resistance Rib : end point VA : reference voltage vg : reference voltage I2 · current Rla : end point R2 : resistance
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