201044883 tiu-2UU5-0030-TW 30366twf.doc/n 六、發明說明： 【發明所屬之技術領域】 本發明是有關於一種色光+ 一種利用光感測器的自動白系统，且特別是有關於 balance，AWB)系統及其方法。平衡（automatic white 【先前技術】 隨著投影顯示技術的進步，201044883 tiu-2UU5-0030-TW 30366twf.doc/n VI. Description of the Invention: [Technical Field] The present invention relates to a color light + an automatic white system using a light sensor, and particularly relates to balance , AWB) systems and methods. Balance (automatic white) [Progress] With the advancement of projection display technology,
O 〇 有急遽的發展與顯著的突破。目來投影系統與設備已 三種：陰極射線管(CRT)、液投影機_主要可分為 及數位光源處理器。其中液日曰;^面板(泛指液晶投影機） 整的特點而廣泛地使用。W細其可攜性與便於調 液晶投影機具備體積小、 極卿)而有著高亮度的優 發出白光至—液晶_ 1 又而a，液日日技衫機 光、綠光以及誌本件’此白光是由^ΕΙ)發出的紅 而吕’f翻白平衡是—個相當重要的課題场機 出的顏色=有!製程有關’所以咖發 晶顯亍元株ί 成 種色光各有其色偏，因此液 德2 牛，”、員不的影像投影至螢幕時，可能會與實 像有明顯的差里。ml ^ 此曰/、只丨不的影 的白平衡紐口此，為了使液晶投影機能夠維持適當 性，以絲I解 所發出的色光之色偏程度有其必要 9由回授來補償並控制LED而實現白平衡。 201044883 -刪 0-TW 30366twf.d〇c/n 在習知技藝中’傳統的液晶投影機通常需具備三個色 彩感測器來實現白平衡。這三個色彩感測器分別用來偵測 對應色光的色偏，使液晶投影機得以依據偵測結果來調整 LED的電力IL ’而實現白平衡。然而，在液晶投影機中使用 三個色彩感測器來實現白平衡花費較多的成本。昂貴的色 彩感測器不利於減少成本，因此需要一種適宜的白平衡系 統 【發明内容】 本發明之實施例提供一種自動白平衡(automatic white balance ’ AWB)系統及其方法。本發明之實施例所提供之 AWB系統使用一光感測單元來達到光源的白平衡效果， 以減少成本。 本發明之一實施例提供一種AWB系統，其包括一光 源、光感測單元、一類比數位(analog-to-digita卜A/D)轉 換益、—控制單元及—驅動電路。上述光源依序提供多個 色光’其中上述色光包括—第—色光及—第二色光 原所發出之色光的亮度，並分別輪出對應於 弟一色光之-第-類比訊號及對應於第二色光之 比訊號。A/D轉換器耦接光感測單 一 與第二類比訊號分別轉 1亚以―類比訊號 如虎。控辟元_ A/D轉換器，並 —弟-數位 一第二預設值的比例，計算第—色 預设值與 二色光之一第二修正量，其中第之一第—修正量與第 別對應第-色光與第二色光值與第二預設值分 動電路耦接控制單元，並 201044883 HD-2008-0030-TW 30366twf.doc/n 依據第一修正量與第二修正量來驅動光源以使多個色光自 動達到白平衡。O 〇 There is an impetuous development and a significant breakthrough. There are three kinds of projection systems and devices: cathode ray tube (CRT) and liquid projector _ can be mainly divided into digital light source processors. Among them, the liquid sputum; ^ panel (referred to as liquid crystal projector) is widely used. W fine portability and easy to adjust LCD projector with small size, very fine) and high brightness, excellent white light to - liquid crystal _ 1 and a, liquid Japanese technology machine light, green light and Zhiben' This white light is emitted by ^ΕΙ) red and Lu 'f white balance is a very important topic of the field machine color = there! Process related 'so so coffee crystal display 亍元株 成 each color has its own Color shift, so liquid Germany 2 cattle,", when the image of the staff is not projected to the screen, there may be a significant difference with the real image. ml ^ This 曰 /, only the shadow of the white balance button, in order to make The liquid crystal projector can maintain the appropriateness, and the degree of color shift of the color light emitted by the silk I solution is necessary. 9 is compensated by the feedback to control and control the LED to achieve white balance. 201044883 - Delete 0-TW 30366twf.d〇c/n In the conventional art, 'traditional liquid crystal projectors usually need three color sensors to achieve white balance. These three color sensors are used to detect the color shift of the corresponding color light, so that the liquid crystal projector can be detected. The result is measured to adjust the power IL' of the LED to achieve white balance. However, in the liquid The use of three color sensors in a projector to achieve white balance costs more. Expensive color sensors are not conducive to cost reduction, and therefore a suitable white balance system is needed. [Invention] Embodiments of the present invention provide a An automatic white balance 'AWB system and method thereof. The AWB system provided by the embodiments of the present invention uses a light sensing unit to achieve a white balance effect of the light source to reduce the cost. An embodiment of the present invention provides An AWB system comprising a light source, a light sensing unit, an analog-to-digita (A/D) conversion benefit, a control unit, and a drive circuit. The light source sequentially provides a plurality of color lights. The color light includes - the first color light and the brightness of the color light emitted by the second color light source, and respectively rotates the -first analog signal corresponding to the first color light and the specific signal corresponding to the second color light. A/D converter coupling The light-sensing single and second analog signals are respectively converted to 1 Asia-like analog signal such as Tiger. Controlling the source _ A/D converter, and the ratio of the younger-digit to the second preset value Calculating a first color preset value and a second correction amount of the two color lights, wherein the first first correction amount and the first corresponding first color light and the second color light value and the second preset value transfer circuit are coupled to the control unit And 201044883 HD-2008-0030-TW 30366twf.doc/n The light source is driven according to the first correction amount and the second correction amount to automatically achieve a white balance of the plurality of color lights.
本發明之一實施例提供一種用於AWB系統的AWB 方法，其步驟如下。（1)藉由一光源提供多個色光。其中， 上述色光包括一第一色光與一第二色光。藉由一光感 測單元感測色光，以獲得對應於第一色光之—第一類比訊An embodiment of the present invention provides an AWB method for an AWB system, the steps of which are as follows. (1) A plurality of color lights are provided by a light source. The color light includes a first color light and a second color light. Sensing the color light by a light sensing unit to obtain a first analogy corresponding to the first color light
號及對應於第二色光之一第二類比訊號。藉由一 A/D 》 轉換器將第一類比訊號與第二類比訊號分別轉換成一第一 ，位訊號與一第二數位訊號。（4)藉由一控制單元依據一 第一預設值與一第二預設值的比例，計算第—色光之一第 t正里與第一色光之一第二修正量。其中，第—預設值 與第二預設值分別對應第一色光與第二色光。藉由— 驅動電路依據第一修正量與第二修正量來驅動光源，以使 光源提供的色光可自動達到白平衡。據此，第—色光與〜 -色光的AWB得以實現。此外，上述步驟的次 = 以限定本發明。 τι非用 〇 I發明之-實施财，光感測單处包括—光哭 二一光感測電路。光感測器感測上述光源所發出之色光时 出對應於第—色光之一第一類比訊號與=第亚=輪 —第二類比訊號。 —' 色光之 在本發明之實施例的AWB系統中，利用其讀 使得光源提供的色光自動達到白平衡。本發明之 只也例的AWB系統具有耦接於光感測電路的光感測哭， 201044883 ML»-2〇U8-UUJ〇-TW 30366twf.doc/n 其有別於使聽彩制ϋ的白平衡系統。使用本發明之實 施例的AWB系狀投影裝置，藉由紐測_實現多^ 色光的白平衡’而非使用色彩感測器。因此，使用本發明 之實施例的AWB系統之投影裝置可減少其製作成本。 為讓本發明之上述特徵和優點能更明顯易懂，下文特 舉實施例，並配合所附圖式作詳細說明如下。 【實施方式】 昂貴的色彩感測器會增加投影裝置的製作成本。因 此，需要一種適當的自動白平衡系統及其方法以減少其製 作成本。在此，本發明之實施例提供一種AWB系統及其 方法來減少投影裝置的製作成本。 〃 圖1為本發明一實施例之AWB系統的方塊圖。請參 照圖1，在本實施例中，AWB系統1〇〇包括一光源1〇2、 一光感測單元104、一類比數位(A/D)轉換器1〇6、一控制 卓元108以及一驅動電路11〇。光源1〇2例如是一發光二 極體(LED)光源。除此之外，光感測單元1〇4更包括一光 感測器112及一光感測電路114。在本實施例中，光感測 器112感測LED光源102所發出的色光之亮度，而光感測 電路114依據感測到的色光亮度輸出一類比訊號。 圖2繪示一液晶投影機(LCP)，其使用圖1之AWB系 統。請參照圖2，LCP 200包括AWB系統100、一微顯示 面板210、一全内反射棱鏡220(TIRprism)以及一投影鏡頭 230。值得注意的是，本實施例之LCP 200例如是一單晶 矽反射式投影機，在此僅用以例示說明，並非用以限定本 201044883 HD-20〇8-0〇3〇.tW 30366twf.doc/n 發明。 請參照圖2，舉例來說，LCP 2〇〇使用色序法將一使 用者所需的影像投影至一螢幕(未繪示）。LED光源1〇2適 於提供一照明光束L1，其中照明光束L1例如是紅色、綠 色或藍色。微顯示面板21〇置於照明光束的傳遞路徑 上。微顯示面板210適於將照明光束L1轉換成影像光束 L2。接著’影像光束L2透過TIR棱鏡220反射到投影鏡 D 頭230。之後，投影鏡頭230將影像光束L2投影到螢幕上 (未綠示）。在本領域具有通常知識者當知LCP 200的基本 運作，在此便不再加以贅述。 對LCP的顯示品質來說，白平衡是一個相當重要的課 題。在本實施例中，具有光感測單元104的AWB系統1〇〇 藉由其AWB方法以確保LCP 200的顯示品質。 圖3為本發明一實施例之AWB方法的流程圖。請同 時參照圖1至圖3，LED光源102適於提供一照明光束L1， 其中照明光束L1例如是紅色、綠色或藍色。首先，在步 Ο 驟S301中，驅動電路110驅動LED光源102以最大亮度 發出紅色光束。於本實施例中，驅動電路110使用 光調變方法來驅動LED光源102。PWM光調變方法利用 一固定電流來驅動光源102中的LED，並藉由LED開啟 與關閉的時間比例(duty ratio)來達到調節亮度的目的。在 此，當LED光源102發出最大亮度的紅色光束時，驅動電 路110例如是用大約80%的時間比例的驅動訊號DrvJR來 驅動LED光源102。於其他實施例中，驅動電路110可用 201044883 HD-2008-〇U30-TW 30366twf.doc/n 類比調變方法來驅動LED光源102。類比調變方法是藉由 改變流經光源102中的LED之電流來調節亮度。 於此同日具有白色輸入圖樣(white input pattern)的微 喊示面板210將最大亮度之紅色光束透過TIR稜鏡220反 射到投影鏡頭230。接著，光感測單元1〇4透過光感測器 112感測具有最大免度的紅色光束之亮度p(R)。之後，在 步驟S302中，光感測單元1〇4進一步透過光感測電路114 輸出對應於紅色光束之第一類比訊號給A/D轉換器1〇6。 繼之，在步驟S303中，耦接於光感測單元1〇4的A/D轉 換器106將第一類比訊號轉換成第一數位訊號，並輸出給 控制單元108。 ^在本實施例中’控制單元1〇8在接收第一數位訊號 後’會暫存紅色光束之π度L’(R)的相關資料。在步驟幻〇4 中，若控制單元108只有紅色、、綠色或藍色光束之亮度的 相關資料’則LED光源1G2會改變其所發出之光束的顏 色，因此整個流程會回到步驟S301。例如，在步驟S3〇4 中’當控制單元108只有紅色光束之亮度的相關資料時， 整個流程會回到步驟S301。因此，在步驟S3〇1中， 光源將會改為發出綠色光束。在本實施例中，步驟s3〇i 到步驟S304的迴圈會不斷重覆，直到控制單元1〇8具有 紅色光束之亮度L’(R)、綠色光束之亮度L，(G)以及薛色光 束之亮度L，(B)的相關資料。 1 在迴圈結束之後，於步驟S305中，控制單元ι〇8計 异第一修正量rL’(R)、第二修正量gL，(G)以及第三修正量 201044883 HD-2008-0030-TW 30366twf.doc/a bL (B)。在本實施例中，控制單元1〇8依據下列方程式來 計算上述三個修正量： -^---- L(G) L{B) L(R)~rL'(R) 1' (G) - (G) — I； (β)—从'(5) ⑴ h其中L(R)為第一預設值，L(G)為第二預設值，l(B) 為第二預設值，L’(R)為紅色光束的亮度，L，(G)為綠色光束 的焭度、’ l’(b)為藍色光束的亮度，rL，(R)為第一修正量， gL’fG)為第二修正量，而bL，(B)為第三修正量。此外，上 述二個色光亮度L’(R)、L，(G)及L，(B)由耦接光感測電路114 之光感測器112在步驟S302中分別量測而得。由方程式 可知，控制單元108可設定計算所得之r、g、b值的其中 之一為零而另外兩個為負。因此，一旦知道是r、g、b值 的其中之一為零，即可得兩個值為負。 如此，控制單元108藉由方程式(1)可得rL,(R)、gL,(G) 以及^，⑻王個修正量。在步驟請6中，驅動電路ιι〇 依據計算結果细PWM光輕方法來㈣㈣光源 〇 102。在控制單元108的控制之T，PWM光調變方法利用 調整過的固定電流及調整過的時間比例(duty rati。)來驅動 LED 光源 102。And a second analog signal corresponding to one of the second color lights. The first analog signal and the second analog signal are respectively converted into a first bit signal and a second digital signal by an A/D converter. (4) Calculating, by a control unit, a second correction amount of one of the t-th positive and the first color light according to a ratio of a first preset value to a second preset value. The first preset value and the second preset value respectively correspond to the first color light and the second color light. The driving circuit drives the light source according to the first correction amount and the second correction amount, so that the color light provided by the light source can automatically reach white balance. Accordingly, the AWB of the first-color light and the ~-color light can be realized. Furthermore, the above steps are sub- = to limit the invention. Τι非用 〇 I invented - implementation of wealth, light sensing singles include - light crying two light sensing circuit. The light sensor senses the color light emitted by the light source corresponding to the first analog signal of the first color light and the second analog signal of the second sub-round. - 'Colored light In the AWB system of the embodiment of the present invention, the read light is used to cause the color light provided by the light source to automatically reach white balance. The AWB system of the present invention has a light sensing cry coupled to the light sensing circuit, 201044883 ML»-2〇U8-UUJ〇-TW 30366twf.doc/n which is different from the sound system White balance system. The AWB-based projection apparatus of the embodiment of the present invention is used to realize white balance of multi-color light instead of using a color sensor. Therefore, the projection apparatus of the AWB system using the embodiment of the present invention can reduce the manufacturing cost thereof. The above described features and advantages of the present invention will become more apparent from the description of the appended claims. [Embodiment] An expensive color sensor increases the manufacturing cost of the projection device. Therefore, there is a need for a suitable automatic white balance system and method thereof to reduce its manufacturing costs. Here, embodiments of the present invention provide an AWB system and method thereof to reduce the manufacturing cost of a projection apparatus. 1 is a block diagram of an AWB system in accordance with an embodiment of the present invention. Referring to FIG. 1 , in the embodiment, the AWB system 1 includes a light source 1 , 2 , a light sensing unit 104 , an analog-to-digital (A/D) converter 1〇6, a control unit 108, and A drive circuit 11 〇. The light source 1〇2 is, for example, a light emitting diode (LED) light source. In addition, the light sensing unit 1〇4 further includes a light sensor 112 and a light sensing circuit 114. In this embodiment, the photo sensor 112 senses the brightness of the color light emitted by the LED light source 102, and the light sensing circuit 114 outputs an analog signal according to the sensed color light brightness. Figure 2 illustrates a liquid crystal projector (LCP) that uses the AWB system of Figure 1. Referring to FIG. 2, the LCP 200 includes an AWB system 100, a microdisplay panel 210, a total internal reflection prism 220 (TIRprism), and a projection lens 230. It should be noted that the LCP 200 of the present embodiment is, for example, a single crystal 矽 reflective projector, which is only used for illustrative purposes, and is not intended to limit the present 201044883 HD-20〇8-0〇3〇.tW 30366twf. Doc/n invention. Referring to Figure 2, for example, the LCP 2 投影 uses color grading to project a desired image of a user onto a screen (not shown). The LED light source 1〇2 is adapted to provide an illumination light beam L1, wherein the illumination light beam L1 is, for example, red, green or blue. The micro display panel 21 is placed on the transmission path of the illumination beam. The micro display panel 210 is adapted to convert the illumination beam L1 into an image beam L2. The image beam L2 is then reflected through the TIR prism 220 to the projection D head 230. Thereafter, the projection lens 230 projects the image light beam L2 onto the screen (not shown in green). Those of ordinary skill in the art are aware of the basic operation of the LCP 200 and will not be described here. White balance is a very important topic for the display quality of LCP. In the present embodiment, the AWB system 1 having the light sensing unit 104 ensures the display quality of the LCP 200 by its AWB method. FIG. 3 is a flowchart of an AWB method according to an embodiment of the present invention. Referring to Figures 1 through 3, the LED light source 102 is adapted to provide an illumination beam L1, wherein the illumination beam L1 is, for example, red, green or blue. First, in step S301, the driving circuit 110 drives the LED light source 102 to emit a red light beam with maximum brightness. In the present embodiment, the drive circuit 110 uses the light modulation method to drive the LED light source 102. The PWM light modulation method uses a fixed current to drive the LEDs in the light source 102, and achieves the purpose of adjusting the brightness by the duty ratio of the LEDs being turned on and off. Here, when the LED light source 102 emits a red light beam of maximum brightness, the driving circuit 110 drives the LED light source 102, for example, with a driving signal DrvJR of a time ratio of about 80%. In other embodiments, the driver circuit 110 can drive the LED light source 102 using the 201044883 HD-2008-〇U30-TW 30366 twf.doc/n analog modulation method. The analog modulation method adjusts the brightness by changing the current flowing through the LEDs in the light source 102. On the same day, the micro-shock panel 210 having a white input pattern reflects the red light beam of the maximum brightness through the TIR 稜鏡 220 to the projection lens 230. Next, the light sensing unit 1〇4 senses the brightness p(R) of the red light beam having the maximum degree of exemption through the light sensor 112. Then, in step S302, the light sensing unit 1〇4 further transmits a first analog signal corresponding to the red light beam to the A/D converter 1〇6 through the light sensing circuit 114. Then, in step S303, the A/D converter 106 coupled to the photo sensing unit 1〇4 converts the first analog signal into a first digital signal and outputs it to the control unit 108. In the present embodiment, the control unit 1〇8 temporarily stores the relevant information of the π degree L'(R) of the red light beam after receiving the first digital signal. In step Magic 4, if the control unit 108 has only the relevant information of the brightness of the red, green or blue light beam, the LED light source 1G2 changes the color of the light beam emitted therefrom, so the entire flow returns to step S301. For example, in step S3〇4, when the control unit 108 has only the relevant information of the brightness of the red light beam, the entire flow returns to step S301. Therefore, in step S3〇1, the light source will instead emit a green light beam. In this embodiment, the loop from step s3〇i to step S304 is repeated until the control unit 1〇8 has the brightness L'(R) of the red beam, the brightness L of the green beam, (G), and the color of the color. The brightness of the beam L, (B) related information. 1 After the end of the loop, in step S305, the control unit ι8 varies the first correction amount rL'(R), the second correction amount gL, (G), and the third correction amount 201044883 HD-2008-0030- TW 30366twf.doc/a bL (B). In the present embodiment, the control unit 〇8 calculates the above three correction amounts according to the following equation: -^---- L(G) L{B) L(R)~rL'(R) 1' (G ) - (G) — I; (β)—From '(5) (1) h where L(R) is the first preset value, L(G) is the second preset value, and l(B) is the second preset Set the value, L'(R) is the brightness of the red beam, L, (G) is the intensity of the green beam, 'l' (b) is the brightness of the blue beam, and rL, (R) is the first correction amount. gL'fG) is the second correction amount, and bL, (B) is the third correction amount. Further, the above two color light luminances L'(R), L, (G) and L, (B) are respectively measured by the photo sensor 112 coupled to the light sensing circuit 114 in step S302. As can be seen from the equation, control unit 108 can set one of the calculated r, g, b values to be zero and the other two to be negative. Therefore, once you know that one of the values of r, g, and b is zero, you can get two values that are negative. Thus, the control unit 108 obtains rL, (R), gL, (G), and ^, (8) king correction amounts by the equation (1). In step 6, the drive circuit ιι〇 according to the calculation result fine PWM light method to (4) (four) light source 〇 102. At the control T of the control unit 108, the PWM light modulation method uses the adjusted fixed current and the adjusted time ratio (duty rati) to drive the LED light source 102.
例如，依據計算的結果’控制單元1〇8可將驅動電路 110所輸出的驅動電流調整為_對應的固定電流，而此時 驅動訊號Drv_R的時間比例為8G%。因此，_電路nQ 以修正過的驅動訊號Drv_R，來驅動咖光源ι〇2，而其時 間比例則為8G%+8G%xr。類似地，驅動電路UG分別以修 正後的驅動訊號Drv—G，及Drv—B，來驅動咖光源1〇2。 9 201044883 HD-2008-0030-TW 30366twf.doc/n 修正後的驅動訊號Drv_G’及Drv一B ’的時間比例分別為 80%+80%xg及80%+80%xb。因此，光感測器112所量測 到紅色、綠色及藍色光束的亮度滿足方程式（1)。在其他實 施例中，驅動訊號Drv一R、Drv一G以及Drv_B的時間比例 可大約為90%及70%等等。 如此一來，紅色、綠色及藍色光束亮度的比例即等於 第一預設值L(R)、第二預設值L(G)及第三預設值L(B)的 比例。因此，藉由本實施例之AWB系統及其方法，可使 在LCP 200之白平衡的目的得以實現。與傳統使用三個色 彩感測器分別依不同的色光偵測對應之色偏的LCP相 比’本實施例之LCP 200利用光感測器112來感測LED 所發出之光束的亮度，而不論LED所發出的光束是何種顏 色。因此’ LCP 200利用光感測器in來實現白平衡，比 起傳統使用三個色彩感測器的LCP具有更低的成本。以下 實施例將說明如何得到第一預設值L(R)、第二預設值l(R) 及第三預設值L(B)。 圖4是上述實施例中取得第一預設值、第二預設值及 苐二預0又值方法的流程圖。在本實施例中，使用^一個跟量 產的LCP 200完全一樣的LCP來取得第一預設值L(R)、 第二預設值L(G)及第三預設值L(B)。請同時參照圖2及圖 4，在上述LCP的影像光束L2的傳遞路徑上，放置一光學 量測儀器來取得第一預設值L(R)、第二預設值L(G)以及第 三預設值L(B)。在此，光學量測儀器例如是一色度計 (Chroma meter)。在步驟 S402 中，LCP 的 LED 光源 102 201044883 HD-2008-0030-TW 30366twf.doc/n 以最大亮度同時發出紅色、綠色以及藍色光束。在此同時， LCP的微顯示面板210將紅色、綠色以及藍色光束反射到 色度計，其中微顯示面板具有一白色輸入圖樣。接著，在 步驟S404中，色度計量測色度座標(x，y)。之後’在步驟 S406中，參照步驟S404色度計量測的色度座標(x，y)，手 動調整LCP的LED光源1〇2以達到白平衡。因此，在步 驟S408中，藉由LCP的光感測器112取得第一預設值 Θ L(R)、第二預設值l(G)以及第三預設值l(B)。預設值 L(R)、L(G)以及L(B)可預先記錄於其他的LCP中（例如圖 2的LCP 200)以進行圖3的白平衡方法。 在本實施例中，LCP 200的AWB方法在LCP 200 — 開始開機時即可執行。在其他實施例中，LCp 2〇〇的AWB 方法可以在LCP 200運作時執行。 圖5繪示另一液晶投影機(Lcp) ’其使用圖1之awb 系統。请參照圖5，本實施例之LCP 500與圖2的LCP 200 相似，惟兩者之間最主要的差異在於本實施例之光感測器 〇 I12被置於靠近LED光源1〇2。如此一來，在微顯示面板 510、透過TIR稜鏡520將光束反射到投影鏡頭53〇之前， 光感測益即可分別量測光束亮度L，(R)、L，(G)以及L，(B)。 由於光感測器112置於靠近LED光源1〇2,因此即使微顯 示面板51〇不具白色輸入樣式’亦可執行LCP 500的AWB 方法。如此—來，LCP 500的AWB方法可以在]χΡ 500 運作日^被執行。另外，本實施例之LCP 500的AWB方法 類似於圖2之LCP 200，在此便不再贅述。 11 201044883 HD-2008-0030-TW 30366twf.d〇〇/n 綜上所述，依據本發明之實施例之使用光感測器的 AWB系統，其有別於傳統使用三個色彩感測器的AWB系 統。也就是說，使用本發明之實施例之AWB系統的LCP， 其色彩光束之白平衡是使用光感測器實現的，而非使用色 彩感測器。因此’藉由調整驅動電流及時間比例，可使光 感測器量測到的光束亮度與預設值一致，而不論光束是什 麼顏色。相較於傳統使用三個色彩感測器的LCP，本發明 之實施例之AWB系統利用光感測器達成白平衡的目的， 進而使得LCP可具有較低的製作成本。因此，使用本發明 £ 之實施例之AWB系統可減少投影裝置的製作成本。 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’任何所屬技術領域中具有通常知識者，在不脫離 本發明之精神和範圍内，當可作些許之更動與潤飾，故本 發明之保護範圍當視後附之申請專利範圍所界定者為準。 【圖式簡單說明】 圖1為本發明一實施例之AWB系統的方塊圖。 圖2鳍'示一液晶投影機(LCP)，其使用圖1之AWB系 統。 ’ ◎ 圖3為本發明一實施例之AWB方法的流程圖。 圖4是上述實施例中取得第一預設值、第二預設值及 第三預設值方法的流程圖。For example, based on the result of the calculation, the control unit 1〇8 can adjust the drive current outputted by the drive circuit 110 to a fixed current corresponding to _, and the time ratio of the drive signal Drv_R at this time is 8 G%. Therefore, the _circuit nQ drives the coffee source ι〇2 with the modified drive signal Drv_R, and the time ratio is 8G%+8G%xr. Similarly, the drive circuit UG drives the coffee source 1〇2 with the corrected drive signals Drv_G and Drv-B, respectively. 9 201044883 HD-2008-0030-TW 30366twf.doc/n The time ratios of the modified drive signals Drv_G' and Drv-B' are 80%+80%xg and 80%+80%xb, respectively. Therefore, the luminances of the red, green, and blue light beams measured by the photo sensor 112 satisfy the equation (1). In other embodiments, the time ratios of the drive signals Drv-R, Drv-G, and Drv_B may be approximately 90% and 70%, and the like. In this way, the ratio of the brightness of the red, green and blue light beams is equal to the ratio of the first preset value L(R), the second preset value L(G) and the third preset value L(B). Therefore, with the AWB system of the present embodiment and the method thereof, the purpose of white balance in the LCP 200 can be achieved. The LCP 200 of the present embodiment uses the photo sensor 112 to sense the brightness of the light beam emitted by the LED, regardless of the LCP used by the conventional color sensor to detect the corresponding color shift. What color is the beam emitted by the LED. Therefore, the LCP 200 utilizes the light sensor in to achieve white balance, which is lower cost than the conventional LCP using three color sensors. The following embodiment will explain how to obtain the first preset value L(R), the second preset value l(R), and the third preset value L(B). 4 is a flow chart of a method for obtaining a first preset value, a second preset value, and a second pre-zero value in the above embodiment. In this embodiment, the first preset value L(R), the second preset value L(G), and the third preset value L(B) are obtained using an LCP that is identical to the mass-produced LCP 200. . Referring to FIG. 2 and FIG. 4 simultaneously, an optical measuring instrument is placed on the transmission path of the image light beam L2 of the LCP to obtain a first preset value L(R), a second preset value L(G), and a Three preset values L (B). Here, the optical measuring instrument is, for example, a Chroma meter. In step S402, the LED light source of the LCP 102 201044883 HD-2008-0030-TW 30366twf.doc/n simultaneously emits red, green and blue light beams at maximum brightness. At the same time, the LCP's microdisplay panel 210 reflects the red, green, and blue beams to the colorimeter, where the microdisplay panel has a white input pattern. Next, in step S404, the chromaticity measures the chromaticity coordinates (x, y). Thereafter, in step S406, referring to the chromaticity coordinates (x, y) of the chromaticity measurement in step S404, the LED light source 1〇2 of the LCP is manually adjusted to achieve white balance. Therefore, in step S408, the first preset value Θ L(R), the second preset value l(G), and the third preset value l(B) are obtained by the light sensor 112 of the LCP. The preset values L(R), L(G), and L(B) may be pre-recorded in other LCPs (e.g., LCP 200 of Fig. 2) to perform the white balance method of Fig. 3. In this embodiment, the AWB method of the LCP 200 can be performed at the start of the LCP 200. In other embodiments, the LCW 2〇〇 AWB method can be performed while the LCP 200 is operating. Figure 5 illustrates another liquid crystal projector (Lcp)' which uses the awb system of Figure 1. Referring to FIG. 5, the LCP 500 of the present embodiment is similar to the LCP 200 of FIG. 2, but the most significant difference between the two is that the photo sensor 〇I12 of the present embodiment is placed close to the LED light source 〇2. In this way, before the micro display panel 510 and the TIR 520 transmit the light beam to the projection lens 53 ,, the light perception can measure the beam brightness L, (R), L, (G) and L, respectively. (B). Since the photo sensor 112 is placed close to the LED light source 1〇2, the AWB method of the LCP 500 can be performed even if the micro display panel 51 does not have a white input pattern. As such, the AWB method of the LCP 500 can be executed on the χΡ 500 operating day. In addition, the AWB method of the LCP 500 of the present embodiment is similar to the LCP 200 of Fig. 2, and will not be described again here. 11 201044883 HD-2008-0030-TW 30366twf.d〇〇/n In summary, the AWB system using the light sensor according to an embodiment of the present invention is different from the conventional use of three color sensors. AWB system. That is, with the LCP of the AWB system of the embodiment of the present invention, the white balance of the color beam is realized using a photo sensor instead of using a color sensor. Therefore, by adjusting the drive current and time ratio, the brightness of the beam measured by the photosensor can be made to match the preset value regardless of the color of the beam. Compared to the conventional LCP using three color sensors, the AWB system of the embodiment of the present invention utilizes a light sensor to achieve white balance, thereby making the LCP less expensive to manufacture. Therefore, the AWB system using the embodiment of the present invention can reduce the manufacturing cost of the projection apparatus. The present invention has been disclosed in the above embodiments, and it is not intended to limit the invention to those skilled in the art, and it is possible to make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an AWB system according to an embodiment of the present invention. Figure 2 shows a liquid crystal projector (LCP) which uses the AWB system of Figure 1. FIG. 3 is a flow chart of an AWB method according to an embodiment of the present invention. 4 is a flow chart of a method for obtaining a first preset value, a second preset value, and a third preset value in the above embodiment.
圖5緣示另一液晶投影機(LCP)，其使用圖1之AWB 糸統。 12 201044883 HD-2008-0030-TW 30366twf.doc/n 【主要元件符號說明】 100 : AWB 系統 200、500 :液晶投影機(LCP) 102 :光源 104 :光感測單元 106 : A/D轉換器 108 :控制單元 110 :驅動電路 112 :光感測器 114 :光感測電路 210、510 :微顯示面板 220 : TIR 稜鏡 230 :投影鏡頭 L1 :照明光束 L2 :影像光束 〇 13Figure 5 illustrates another liquid crystal projector (LCP) that uses the AWB system of Figure 1. 12 201044883 HD-2008-0030-TW 30366twf.doc/n [Main component symbol description] 100 : AWB system 200, 500 : Liquid crystal projector (LCP) 102 : Light source 104 : Light sensing unit 106 : A / D converter 108: control unit 110: drive circuit 112: light sensor 114: light sensing circuit 210, 510: micro display panel 220: TIR 稜鏡 230: projection lens L1: illumination beam L2: image beam 〇 13