TW201342356A - Brightness compensation method and local dimming circuit and liquid crystal display thereof - Google Patents

Brightness compensation method and local dimming circuit and liquid crystal display thereof Download PDF

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TW201342356A
TW201342356A TW101113220A TW101113220A TW201342356A TW 201342356 A TW201342356 A TW 201342356A TW 101113220 A TW101113220 A TW 101113220A TW 101113220 A TW101113220 A TW 101113220A TW 201342356 A TW201342356 A TW 201342356A
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backlight
image data
brightness
backlights
display areas
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TW101113220A
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Chinese (zh)
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Heng Yu
Min Wei
Jian-De Jiang
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Novatek Microelectronics Corp
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Abstract

The present invention discloses a brightness compensation method. The brightness compensation method includes controlling a plurality of backlights of a plurality of display area to turn on with a plurality of backlight intensities; calculating a plurality of total backlight intensities; calculating a plurality of actual backlight intensities according to the plurality of total backlight intensities and a backlight scanning ratio; dividing a plurality of maximum backlight intensities when the plurality of backlights are fully turned on with the plurality of actual backlight intensities, to generate a plurality of compensation gains; and display a compensated image data with a plurality of compensated image intensities after compensating a plurality of image intensities corresponding to the plurality of display area of an image data with the plurality of compensation gains.

Description

亮度補償方法及其區域調光電路與液晶顯示器Brightness compensation method and regional dimming circuit and liquid crystal display

本發明係指一種亮度補償方法及其區域調光電路與液晶顯示器，尤指一種可同時補償區域調光(local dimming)及背光掃描(scanning backlight)的亮度損失，以顯示正常影像的亮度補償方法及其區域調光電路與液晶顯示器。The invention relates to a brightness compensation method, a regional dimming circuit thereof and a liquid crystal display, in particular to a brightness compensation method capable of simultaneously compensating for brightness loss of local dimming and scanning backlight to display normal image And its regional dimming circuit and liquid crystal display.

一般來說，區域調光(local dimming)技術可根據所欲顯示之影像資料，將液晶顯示器(liquid crystal display，LCD)中對應於顯示面板上不同顯示區域之不同背光源以不同亮度開啟，以達到節省耗電量的目的。In general, the local dimming technology can open different backlights corresponding to different display areas on the display panel in a liquid crystal display (LCD) according to the image data to be displayed. To achieve the purpose of saving power.

舉例來說，若影像資料於一顯示區域之影像較亮而於另一顯示區域之影像較暗，則區域調光技術會控制作為該顯示區域之背光源之冷陰極燈管(Cold Cathode Fluorescent Lamp，CCFL)或發光二極體(Light Emitting Diode，LED)以較亮的背光亮度開啟，而該另一顯示區域之背光源以較暗的背光亮度開啟，因此相較於一般操作下將全部背光源以最大背光亮度開啟，區域調光技術可節省耗電量。For example, if the image data in one display area is brighter and the image in the other display area is darker, the area dimming technology controls the cold cathode light tube (Cold Cathode Fluorescent Lamp) as the backlight of the display area. , CCFL) or Light Emitting Diode (LED) is turned on with a brighter backlight brightness, while the backlight of the other display area is turned on with a darker backlight brightness, so that all backlights will be compared to normal operation. The source is turned on with maximum backlight brightness, and area dimming technology saves power.

在此情形下，由於區域調光技術將液晶顯示器中部分顯示區域的背光亮度降低，因此為了避免使用者受到此亮度損失影響，習知區域調光技術會進一步對影像資料中的影像亮度(即液晶偏振導通光線的程度)補償提升後再進行顯示(即藉由增加影像亮度來補償背光亮度降低的損失)，以避免使用者感覺所顯示影像較暗。In this case, since the area dimming technique reduces the backlight brightness of some display areas in the liquid crystal display, in order to prevent the user from being affected by the brightness loss, the conventional area dimming technology further enhances the image brightness in the image data (ie, The degree to which the liquid crystal is polarized to conduct light is compensated and then displayed (ie, by increasing the brightness of the image to compensate for the loss of brightness reduction of the backlight) to prevent the user from feeling that the displayed image is dark.

另一方面，習知技術亦可能將區域調光技術搭配背光掃描(scanning backlight)技術實施，透過背光掃描技術將正在進行影像顯示之顯示區域外之其它顯示區域選擇性進行關閉(即液晶顯示器掃描畫素進行顯示時，僅正在進行影像顯示之顯示區域之背光源一定要開啟)，以更進一步節省耗電量。On the other hand, the conventional technology may also implement the area dimming technology with a scanning backlight technology, and selectively turn off other display areas outside the display area where the image display is being performed through the backlight scanning technology (ie, liquid crystal display scanning). When the pixel is displayed, only the backlight of the display area where the image display is being performed must be turned on) to further save power consumption.

然而，習知區域調光技術係將部分顯示區域的背光亮度降低，然後於假設全部背光源皆一直開啟的情況下進行亮度補償，並未考慮到背光掃描技術將部分顯示區域選擇性關閉所造成的亮度損失，因此當區域調光技術搭配背光掃描技術實施時，使用者仍會感覺所顯示影像較暗。有鑑於此，習知技術實有改進之必要。However, the conventional area dimming technique reduces the backlight brightness of some display areas, and then performs brightness compensation on the assumption that all backlights are always on, without considering that the backlight scanning technology selectively turns off part of the display area. The brightness loss, so when the regional dimming technology is implemented with the backlight scanning technology, the user still feels that the displayed image is dark. In view of this, the prior art has been improved.

因此，本發明之主要目的即在於提供一種可同時補償區域調光及背光掃描的亮度損失，以顯示正常影像的亮度補償方法及其區域調光電路與液晶顯示器。Therefore, the main object of the present invention is to provide a brightness compensation method capable of simultaneously compensating for the brightness loss of the area dimming and backlight scanning to display the normal image, and the area dimming circuit and the liquid crystal display.

本發明揭露一種亮度補償方法，用於一液晶顯示器中。該亮度補償方法包含有根據一影像資料，對該液晶顯示器之複數個顯示區域進行區域調光，以控制該複數個顯示區域之複數個背光源以複數個背光亮度開啟；根據複數個漏光係數，計算該複數個顯示區域之複數個總合背光亮度；根據該複數個總合亮度及一背光掃描比例，計算該複數個顯示區域之複數個實際背光亮度；分別將該複數個背光源完全開啟時之複數個最大背光亮度除以該複數個實際背光亮度，以產生複數個補償增益；以及以該複數個補償增益對該影像資料對應之該複數個顯示區域之複數個影像亮度進行補償後，以複數個補償影像亮度顯示一補償影像資料。The invention discloses a brightness compensation method for use in a liquid crystal display. The brightness compensation method includes: performing area dimming on a plurality of display areas of the liquid crystal display according to an image data, and controlling a plurality of backlights of the plurality of display areas to be turned on by a plurality of backlight brightness; according to the plurality of light leakage coefficients, Calculating a plurality of total backlight luminances of the plurality of display regions; calculating a plurality of actual backlight luminances of the plurality of display regions according to the plurality of combined luminances and a backlight scanning ratio; respectively, when the plurality of backlights are completely turned on Dividing a plurality of maximum backlight luminances by the plurality of actual backlight luminances to generate a plurality of compensation gains; and compensating a plurality of image luminances of the plurality of display regions corresponding to the image data with the plurality of compensation gains, A plurality of compensated image brightness displays a compensated image data.

本發明另揭露一種區域調光電路，用於一液晶顯示器中，耦接於一時序控制器及一背光驅動電路，用來接收一影像資料，並執行上述之亮度補償方法。The present invention further discloses a regional dimming circuit for use in a liquid crystal display coupled to a timing controller and a backlight driving circuit for receiving an image data and performing the brightness compensation method described above.

本發明另揭露一種液晶顯示器包含有一液晶螢幕，具有複數個顯示區域；複數個背光源，對應於該複數個顯示區域；一背光驅動電路，用來控制該複數個背光源以複數個背光亮度開啟；一時序控制器，用來接收具有複數個補償影像亮度之一補償影像資料；以及一區域調光電路，用來接收一影像資料，並執行上述之亮度補償方法。The present invention further discloses a liquid crystal display comprising a liquid crystal screen having a plurality of display areas; a plurality of backlights corresponding to the plurality of display areas; and a backlight driving circuit for controlling the plurality of backlights to be turned on by a plurality of backlights a timing controller for receiving one of a plurality of compensated image brightness compensation image data; and a region dimming circuit for receiving an image data and performing the brightness compensation method described above.

請參考第1圖，第1圖為本發明實施例一液晶顯示器10之示意圖。如第1圖所示，液晶顯示器10包含有一液晶螢幕100、背光源BL1～BLx、一背光驅動電路102、一時序控制器104以及一區域調光(local dimming)電路106。簡單來說，液晶螢幕100具有顯示區域DA1～DAx，背光源BL1～BLx較佳為發光二極體(Light Emitting Diode，LED)形式之背光源，分別位於顯示區域DA1～DAx正後方提供背光，區域調光電路106可接收一影像資料ID，再根據影像資料ID指示背光驅動電路102控制背光源BL1～BLx以背光亮度BLI1～BLIx開啟，並產生補償影像資料CID予時序控制器104，使得時序控制器104控制液晶螢幕100顯示補償影像資料CID。Please refer to FIG. 1 , which is a schematic diagram of a liquid crystal display 10 according to an embodiment of the present invention. As shown in FIG. 1, the liquid crystal display 10 includes a liquid crystal screen 100, the backlight BL 1 ~ BL x, a backlight driving circuit 102, a timing controller 104 and an area dimming (local dimming) circuit 106. Briefly, the liquid crystal screen 100 has display areas DA 1 to DA x , and the backlights BL 1 to BL x are preferably backlights in the form of Light Emitting Diodes (LEDs), which are respectively located in the display areas DA 1 to DA. The back side of the x backlight is provided, and the area dimming circuit 106 can receive an image data ID, and then instruct the backlight driving circuit 102 to control the backlights BL 1 to BL x to turn on the backlight brightness BLI 1 to BLI x according to the image data ID, and generate a compensation image. The data CID is applied to the timing controller 104 such that the timing controller 104 controls the liquid crystal screen 100 to display the compensated image data CID.

詳細來說，液晶顯示器10之亮度補償操作，可歸納為一亮度補償流程20，如第2圖所示，其包含以下步驟：In detail, the brightness compensation operation of the liquid crystal display 10 can be summarized into a brightness compensation process 20, as shown in FIG. 2, which includes the following steps:

步驟200：開始。Step 200: Start.

步驟202：根據影像資料ID，對液晶顯示器10之顯示區域DA1～DAx進行區域調光，以控制顯示區域DA1～DAx之背光源BL1～BLx以背光亮度BLI1～BLIx開啟。Step 202: The image data ID, on the display area of the liquid crystal display 10 of DA 1 ~ DA x local dimming, to control the display area DA 1 ~ backlight DA x of BL 1 ~ BL x to the backlight luminance BLI 1 ~ BLI x Open.

步驟204：根據漏光係數(leakage coefficient)LC1～LCz，計算顯示區域DA1～DAx之總合背光亮度TBLI1～TBLIx。Step 204: Calculate the total combined backlight luminances TBLI 1 to TBLI x of the display areas DA 1 to DA x according to the leakage coefficients LC 1 to LC z .

步驟206：根據總合亮度TBLI1～TBLIx及一背光掃描比例(backlight scanning ratio)，計算顯示區域DA1～DAx之實際背光亮度ABLI1～ABLIx。Step 206: Calculate the actual backlight brightnesses ABLI 1 to ABLI x of the display areas DA 1 to DA x according to the total combined brightness TBLI 1 to TBLI x and a backlight scanning ratio.

步驟208：分別將背光源BL1～BLx完全開啟時之最大背光亮度MBLI1～MBLIx除以實際背光亮度ABLI1～ABLIx，以產生補償增益CG1～CGx。Step 208: Dividing the maximum backlight brightness MBLI 1 - MBLI x when the backlights BL 1 BL BL x are fully turned on by the actual backlight brightness ABLI 1 - ABLI x to generate compensation gains CG 1 - CG x , respectively .

步驟210：以補償增益CG1～CGx對影像資料ID對應之顯示區域DA1～DAx之影像亮度II1～IIy進行補償後，以補償影像亮度CII1～CIIy顯示補償影像資料CID。Step 210: Compensating for the image brightnesses II 1 to II y of the display areas DA 1 to DA x corresponding to the image data ID with the compensation gains CG 1 to CG x , and displaying the compensated image data CID with the compensated image brightnesses CII 1 to CII y .

步驟212：結束。Step 212: End.

根據亮度補償流程20，當接收影像資料ID後，區域調光電路106會根據影像資料ID，對液晶顯示器10之顯示區域DA1～DAx進行區域調光，以指示背光驅動電路102控制顯示區域DA1～DAx之背光源BL1～BLx以背光亮度BLI1～BLIx開啟。例如區域調光電路106可統計顯示區域DA1～DAx中每一畫素之最大影像亮度後製成直條圖(histogram)，據以根據影像資料ID對應於顯示區域DA1～DAx全部畫素之影像亮度II1～IIy，決定開啟背光源BL1～BLx之背光亮度BLI1～BLIx之強度(即顯示區域DA1～DAx中總影像亮度較強者，其所對應之背光源以較強背光亮度開啟，而顯示區域DA1～DAx中總影像亮度較弱者，其所對應之背光源以較弱背光亮度開啟)，以節省耗電量。其中，區域調光電路106可根據影像資料ID對應於顯示區域DA1～DAx之影像亮度II1～IIy，產生責任週期(duty cycle)D1～Dx予背光驅動電路102，使得背光驅動電路102以責任週期D1～Dx之長度控制背光源BL1～BLx以背光亮度BLI1～BLIx開啟，例如以脈波寬度調變(pulse width modulation，PWM)或其它方式調變背光源BL1～BLx之背光亮度BLI1～BLIx之強度。According to the brightness compensation process 20, after receiving the image data ID, the area dimming circuit 106 performs area dimming on the display areas DA 1 to DA x of the liquid crystal display 10 according to the image data ID to instruct the backlight driving circuit 102 to control the display area. DA 1 ~ backlight BL DA x 1 ~ BL x to the backlight luminance BLI 1 ~ BLI x opening. For example, the area dimming circuit 106 can calculate the maximum image brightness of each pixel in the display areas DA 1 to DA x and then make a histogram, corresponding to the display areas DA 1 to DA x according to the image data ID. The image brightness II 1 to II y of the pixel determines the intensity of the backlight brightness BLI 1 to BLI x of the backlights BL 1 to BL x (ie, the total image brightness in the display areas DA 1 to DA x is strong, and the corresponding The backlight is turned on with a strong backlight brightness, and the total image brightness in the display areas DA 1 to DA x is weak, and the corresponding backlight is turned on with a weak backlight brightness) to save power consumption. The area dimming circuit 106 can generate a duty cycle D 1 -D x to the backlight driving circuit 102 according to the image data ID corresponding to the image brightnesses II 1 to II y of the display areas DA 1 to DA x , so that the backlight driving circuit 102 to the length of the duty cycle D 1 ~ D x of controlling the backlight BL 1 ~ BL x to the backlight luminance BLI 1 ~ BLI x open, for example, pulse width modulation (pulse width modulation, PWM), or otherwise modulated The intensity of the backlight brightness BLI 1 to BLI x of the backlights BL 1 to BL x .

接著，由於顯示區域DA1～DAx在顯示影像時，各顯示區域周圍顯示區域所對應之背光源亦會提供背光(即漏光)，並非只單純由所對應之各背光源提供各顯示區域背光，因此區域調光電路106可根據漏光係數(leakage coefficient)LC1～LCz，計算顯示區域DA1～DAx之總合背光亮度TBLI1～TBLIx，例如將背光亮度BLI1～BLIx與漏光係數LC1～LCz進行旋積(convolution)，以計算顯示區域DA1～DAx之總合背光亮度TBLI1～TBLIx(即將各顯示區域周圍顯示區域所對應之背光亮度乘上對此顯示區域之漏光係數後，連同各顯示區域所對應背光亮度進行加總)。Then, when the display areas DA 1 to DA x are displayed, the backlight corresponding to the display area around each display area also provides backlight (ie, light leakage), and not only the backlights of the respective display areas are provided by the corresponding backlights. Therefore, the regional dimming circuit 106 can calculate the total combined backlight luminances TBLI 1 to TBLI x of the display regions DA 1 to DA x according to the leakage coefficients LC 1 to LC z , for example, the backlight luminances BLI 1 to BLI x and leakage coefficients LC 1 ~ LC z spin product (convolution), the display area DA 1 ~ to calculate the sum of the brightness of the backlight DA x TBLI 1 ~ TBLI x (coming around each display area of the display area corresponding to the backlight brightness multiplying this After the light leakage coefficient of the display area is added, the brightness of the backlight corresponding to each display area is added.

然後，由於將區域調光技術搭配背光掃描(scanning backlight)技術實施時，背光驅動電路102會根據一背光掃描比例，將正在進行影像顯示之顯示區域外之其它顯示區域選擇性進行關閉，因此區域調光電路106會再根據總合亮度TBLI1～TBLIx及該背光掃描比例，計算顯示區域DA1～DAx之實際背光亮度ABLI1～ABLIx，即將上述背光源BL1～BLx持續開啟下所計算得到之總合亮度TBLI1～TBLIx，乘上背光掃描對背光源BL1～BLx關閉之比例，得到區域調光技術搭配背光掃描技術實施時顯示區域DA1～DAx之實際背光亮度ABLI1～ABLIx。Then, when the area dimming technology is implemented with a scanning backlight technology, the backlight driving circuit 102 selectively turns off other display areas outside the display area where the image display is being performed according to a backlight scanning ratio, so the area is The dimming circuit 106 further calculates the actual backlight brightnesses ABLI 1 to ABLI x of the display areas DA 1 to DA x according to the combined brightness TBLI 1 TBLI x and the backlight scanning ratio, that is, the backlights BL 1 ～BL x are continuously turned on. The total combined brightness TBLI 1 ～ TBLI x calculated by the above is multiplied by the ratio of backlight scanning to the backlight BL 1 ～BL x turned off, and the actual area of the display area DA 1 ～DA x when the area dimming technology is implemented with the backlight scanning technology is obtained. Backlight brightness ABLI 1 ~ ABLI x .

最後，背光驅動電路102再分別將背光源BL1～BLx完全開啟時之最大背光亮度MBLI1～MBLIx除以實際背光亮度ABLI1～ABLIx，以產生補償增益CG1～CGx。因此，背光驅動電路102可以補償增益CG1～CGx對影像資料ID對應之顯示區域DA1～DAx之影像亮度II1～IIy進行補償後，再由時序控制器104以補償影像亮度CII1～CIIy控制液晶螢幕100顯示補償影像資料CID。換言之，由於補償增益CG1～CGx係正常狀態下最大背光亮度MBLI1～MBLIx與進行區域調光及背光掃描下實際背光亮度ABLI1～ABLIx之比值，因此以影像亮度II1～IIy乘上補償增益CG1～CGx所得之影像亮度CII1～CIIy顯示補償影像資料CID時，使用者不會因區域調光及背光掃描感覺所顯示影像較暗。Finally, the backlight driving circuit 102 divides the maximum backlight luminances MBLI 1 to MBLI x when the backlights BL 1 to BL x are fully turned on by the actual backlight luminances ABLI 1 to ABLI x , respectively, to generate compensation gains CG 1 to CG x . Therefore, the backlight driving circuit 102 can compensate the gains CG 1 to CG x to compensate the image brightnesses II 1 to II y of the display areas DA 1 to DA x corresponding to the image data ID, and then compensate the image brightness by the timing controller 104. The 1 to CII y control LCD screen 100 displays the compensated image data CID. In other words, since the compensation gains CG 1 to CG x are the ratios of the maximum backlight luminances MBLI 1 to MBLI x in the normal state to the actual backlight luminances ABLI 1 to ABLI x in the area dimming and backlight scanning, the image brightness II 1 to II is used. When the image brightness CII 1 to CII y obtained by multiplying the compensation gains CG 1 to CG x is displayed, the user does not have a darker image due to the area dimming and backlight scanning.

在此情形下，本發明不只考慮區域調光將部分顯示區域亮度降低所造成的背光亮度損失，而且考慮背光掃描對背光源不持續開啟(即背光掃描比例)所造成的背光亮度損失算出實際背光亮度ABLI1～ABLIx後，才對顯示區域DA1～DAx中全部畫素之影像亮度II1～IIy乘上補償增益CG1～CGx以得到補償影像亮度CII1～CIIy。如此一來，本發明可透過增加影像亮度精確地補償區域調光及背光掃描所造成的背光亮度損失(如時序控制器104可增加源極控制訊號強度以增加液晶偏振導通光線的程度)，使得使用者不會因區域調光及背光掃描感覺所顯示影像較暗。In this case, the present invention not only considers the backlight brightness loss caused by the reduction of the brightness of the partial display area by the area dimming, but also calculates the actual backlight by considering the backlight brightness loss caused by the backlight not being continuously turned on (ie, the backlight scanning ratio). After the brightness ABLI 1 to ABLI x , the image brightnesses II 1 to II y of all the pixels in the display areas DA 1 to DA x are multiplied by the compensation gains CG 1 to CG x to obtain the compensated image luminances CII 1 to CII y . In this way, the present invention can accurately compensate the backlight brightness loss caused by the area dimming and the backlight scanning by increasing the image brightness (for example, the timing controller 104 can increase the source control signal intensity to increase the degree of liquid crystal polarization conduction light), The user does not have a darker image due to area dimming and backlight scanning.

值得注意的是，本發明之主要精神在於同時考慮區域調光將部分顯示區域亮度降低及背光掃描對背光源不持續開啟所造成的背光亮度損失，於算出實際背光亮度ABLI1～ABLIx後再據以增加影像亮度以補償區域調光及背光掃描所造成的背光亮度損失，使得使用者不會因區域調光及背光掃描感覺所顯示影像較暗。本領域具通常知識者當可據以進行修飾或變化，而不限於此。舉例來說，區域調光電路106可整合於主晶片中，但亦可獨立實施。此外，在上述實施例中，步驟202之實施方式係直接以統計顯示區域DA1～DAx中每一畫素之最大影像亮度後，再決定開啟背光源BL1～BLx之背光亮度BLI1～BLIx之強度，在其它實施例中，步驟202亦可根據影像資料ID與前一影像資料ID’(如前一幀，frame)之實際背光亮度ABLI1’～ABLIx’，以遞迴(recursive)方式決定背光源BL1～BLx之背光亮度BLI1～BLIx之強度。It should be noted that the main spirit of the present invention is to simultaneously consider the reduction of the brightness of the partial display area by the regional dimming and the backlight brightness loss caused by the backlight scanning not continuously turning on the backlight, after calculating the actual backlight brightness ABLI 1 - ABLI x According to the increase of image brightness to compensate for the loss of backlight brightness caused by area dimming and backlight scanning, the user does not have a darker image due to regional dimming and backlight scanning. Those skilled in the art will be able to make modifications or variations without limitation thereto. For example, the regional dimming circuit 106 can be integrated into the main wafer, but can also be implemented independently. In addition, in the above embodiment, the implementation of step 202 directly determines the maximum image brightness of each pixel in the regions DA 1 to DA x , and then determines the backlight brightness BLI 1 of the backlights BL 1 to BL x . - intensity of BLI x, in other embodiments, step 202 may 'luminance ABLI 1 (such as the previous frame, frame) the actual backlight' ~ ABLI x based on the image data of the previous image data ID ID ', to recursively The (recursive) mode determines the intensity of the backlight luminances BLI 1 to BLI x of the backlights BL 1 to BL x .

詳細來說，區域調光電路106可先正規化(normalize)透過步驟206於前一影像資料ID’所得之實際背光亮度ABLI1’～ABLIx’，再根據影像資料ID對應之顯示區域DA1～DAx之影像亮度II1～IIy與前一影像資料ID’之實際背光亮度ABLI1’～ABLIx’之差製成直條圖，然後據以決定背光亮度偏移(offset)OF1～OFx。接著，區域調光電路106以背光亮度偏移OF1～OFx對前一影像資料ID’之背光亮度BLI1’～BLIx’進行補償，以控制背光源BL1～BLx以背光亮度BLI1～BLIx開啟。在此情況下，由於顯示區域DA1～DAx在顯示影像時，各顯示區域周圍顯示區域所對應之背光源亦會提供背光，因此考慮漏光所得之背光亮度較為準確，而影像亮度II1～IIy與前一影像資料ID’之實際背光亮度ABLI1’～ABLIx’之差即指示前一影像資料ID’所使用之背光亮度BLI1’～BLIx’需改變以得到適當顯示影像資料ID之背光亮度BLI1～BLIx之程度(如據以改變用於前一幀的責任週期D1’～Dx’之長度以得到用於目前幀的責任週期D1～Dx)。如此一來，本實施例可以遞迴方式準確決定區域調光時背光源BL1～BLx之背光亮度BLI1～BLIx之強度。In detail, the area dimming circuit 106 can normalize the actual backlight brightness ABLI 1 '~ABLI x ' obtained by the previous image data ID' in step 206, and then display the area DA 1 according to the image data ID. ~DA x image brightness II 1 ~ II y and the difference between the actual backlight brightness ABLI 1 '~ABLI x ' of the previous image data ID' is made into a bar graph, and then the backlight brightness offset (offset) OF 1 is determined accordingly. ~OF x . Next, the area dimming circuit 106 compensates the backlight brightness BLI 1 '~BLI x ' of the previous image data ID' with the backlight brightness shifts OF 1 to OF x to control the backlights BL 1 BLBL x to backlight brightness BLI 1 ~ BLI x is on. In this case, since the backlights corresponding to the display areas around the display areas are also provided with backlights when the display areas DA 1 to DA x are displayed, the backlight brightness obtained by considering the light leakage is more accurate, and the image brightness II 1 ～ The difference between the actual backlight brightness ABLI 1 '~ABLI x ' of II y and the previous image data ID' indicates that the backlight brightness BLI 1 '~BLI x ' used in the previous image data ID' needs to be changed to obtain appropriate display image data. The degree of the backlight luminance BLI 1 to BLI x of the ID (as the length of the duty cycle D 1 '~D x ' used for the previous frame is changed to obtain the duty cycle D 1 to D x for the current frame). In this way, the embodiment can accurately determine the intensity of the backlight brightnesses BLI 1 to BLI x of the backlights BL 1 to BL x during the area dimming in a recursive manner.

在習知技術中，區域調光技術係將部分顯示區域的背光亮度降低，然後於假設全部背光源皆一直開啟的情況下進行亮度補償，並未考慮到背光掃描技術將部分顯示區域選擇性關閉所造成的亮度損失，因此當區域調光技術搭配背光掃描技術實施時，使用者仍會感覺所顯示影像較暗。相較之下，本發明同時考慮區域調光將部分顯示區域亮度降低及背光掃描對背光源不持續開啟所造成的背光亮度損失，於算出實際背光亮度ABLI1～ABLIx後再據以增加影像亮度以補償區域調光及背光掃描所造成的背光亮度損失，使得使用者不會因區域調光及背光掃描感覺所顯示影像較暗。In the prior art, the area dimming technique reduces the backlight brightness of a part of the display area, and then performs brightness compensation on the assumption that all the backlights are always on, without considering that the backlight scanning technology selectively turns off part of the display area. The resulting brightness loss, so when the regional dimming technology is implemented with the backlight scanning technology, the user still feels that the displayed image is dark. In contrast, the present invention simultaneously considers the brightness reduction of the partial display area by the area dimming and the backlight brightness loss caused by the backlight scanning not continuously turning on the backlight, and then increasing the image after calculating the actual backlight brightness ABLI 1 to ABLI x . The brightness compensates for the loss of backlight brightness caused by area dimming and backlight scanning, so that the user does not have a darker image due to area dimming and backlight scanning.

以上所述僅為本發明之較佳實施例，凡依本發明申請專利範圍所做之均等變化與修飾，皆應屬本發明之涵蓋範圍。The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

10．．．液晶顯示器10. . . LCD Monitor

100．．．液晶螢幕100. . . LCD screen

102．．．背光驅動電路102. . . Backlight driving circuit

104．．．時序控制器104. . . Timing controller

106．．．區域調光電路106. . . Area dimming circuit

BL1～BLx．．．背光源BL 1 ~ BL x . . . Backlight

ID．．．影像資料ID. . . video material

CID．．．補償影像資料CID. . . Compensation image data

D1～Dx．．．責任週期D 1 ~ D x . . . Cycle of responsibility

20．．．流程20. . . Process

200～212．．．步驟200 to 212. . . step

第1圖為本發明實施例一液晶顯示器之示意圖。FIG. 1 is a schematic view of a liquid crystal display according to an embodiment of the present invention.

第2圖為本發明實施例一亮度補償流程之示意圖。FIG. 2 is a schematic diagram of a brightness compensation process according to an embodiment of the present invention.

20．．．流程20. . . Process

200～212．．．步驟200 to 212. . . step

Claims (10)

一種亮度補償方法，用於一液晶顯示器(liquid crystal display，LCD)中，包含有：根據一影像資料，對該液晶顯示器之複數個顯示區域進行區域調光(local dimming)，以控制該複數個顯示區域之複數個背光源以複數個背光亮度開啟；根據複數個漏光係數(leakage coefficient)，計算該複數個顯示區域之複數個總合背光亮度；根據該複數個總合亮度及一背光掃描比例(backlight scanning ratio)，計算該複數個顯示區域之複數個實際背光亮度；分別將該複數個背光源完全開啟時之複數個最大背光亮度除以該複數個實際背光亮度，以產生複數個補償增益；以及以該複數個補償增益對該影像資料對應之該複數個顯示區域之複數個影像亮度進行補償後，以複數個補償影像亮度顯示一補償影像資料。A brightness compensation method for a liquid crystal display (LCD) includes: local dimming a plurality of display areas of the liquid crystal display according to an image data to control the plurality of The plurality of backlights of the display area are turned on with a plurality of backlight brightnesses; and a plurality of integrated backlight brightnesses of the plurality of display areas are calculated according to a plurality of leakage coefficients; and the plurality of combined brightnesses and a backlight scanning ratio are calculated according to the plurality of display areas (backlight scanning ratio), calculating a plurality of actual backlight brightnesses of the plurality of display areas; respectively dividing the plurality of maximum backlight brightnesses when the plurality of backlights are fully turned on by the plurality of actual backlight brightnesses to generate a plurality of compensation gains And compensating the plurality of image brightnesses of the plurality of display areas corresponding to the image data by using the plurality of compensation gains, and displaying a compensated image data by using the plurality of compensated image brightnesses. 如請求項1所述之亮度補償方法，其中根據該影像資料，對該液晶顯示器之複數個顯示區域進行區域調光，以控制該複數個顯示區域之該複數個背光源以該複數個背光亮度開啟之步驟包含有：根據該影像資料對應於該複數個顯示區域之該複數個影像亮度，決定開啟該複數個背光源之該複數個背光亮度之強度。The brightness compensation method of claim 1, wherein the plurality of display areas of the liquid crystal display are area dimmed according to the image data, to control the plurality of backlights of the plurality of display areas to use the plurality of backlights The step of turning on includes: determining, according to the brightness of the plurality of images corresponding to the plurality of display areas, the brightness of the plurality of backlights for turning on the plurality of backlights. 如請求項1所述之亮度補償方法，其中根據該影像資料，對該液晶顯示器之複數個顯示區域進行區域調光，以控制該複數個顯示區域之該複數個背光源以該複數個背光亮度開啟之步驟包含有：根據該影像資料，以複數個責任週期(duty cycle)之長度控制該複數個背光源以該複數個背光亮度開啟。The brightness compensation method of claim 1, wherein the plurality of display areas of the liquid crystal display are area dimmed according to the image data, to control the plurality of backlights of the plurality of display areas to use the plurality of backlights The step of turning on includes: controlling, according to the image data, the plurality of backlights to be turned on by the plurality of backlight cycles with a plurality of duty cycles. 如請求項1所述之亮度補償方法，其中根據該複數個漏光係數，計算該複數個顯示區域之該複數個總合背光亮度之步驟包含有：將該複數個背光強度與複數個漏光係數進行旋積(convolution)，以計算該複數個顯示區域之複數個總合背光亮度。The brightness compensation method of claim 1, wherein the step of calculating the plurality of integrated backlight luminances of the plurality of display regions according to the plurality of light leakage coefficients comprises: performing the plurality of backlight intensities and the plurality of light leakage coefficients Convolution to calculate a plurality of combined backlight brightness of the plurality of display regions. 如請求項1所述之亮度補償方法，其中根據該影像資料，對該液晶顯示器之複數個顯示區域進行區域調光，以控制該複數個顯示區域之該複數個背光源以該複數個背光亮度開啟之步驟包含有：根據該影像資料與前一影像資料之複數個實際背光亮度，以遞迴(recursive)方式決定該複數個背光亮度之強度。The brightness compensation method of claim 1, wherein the plurality of display areas of the liquid crystal display are area dimmed according to the image data, to control the plurality of backlights of the plurality of display areas to use the plurality of backlights The step of opening includes: determining the intensity of the plurality of backlight brightness in a recursive manner according to the plurality of actual backlight brightnesses of the image data and the previous image data. 如請求項5所述之亮度補償方法，其中根據該影像資料，對該液晶顯示器之複數個顯示區域進行區域調光，以控制該複數個顯示區域之該複數個背光源以該複數個背光亮度開啟之步驟包含有：根據該影像資料對應之該複數個顯示區域之該複數個影像亮度與前一影像資料之複數個實際背光亮度之差，決定複數個背光亮度偏移(offset)。The brightness compensation method of claim 5, wherein the plurality of display areas of the liquid crystal display are area dimmed according to the image data, to control the plurality of backlights of the plurality of display areas with the plurality of backlight brightnesses The step of turning on includes determining a plurality of backlight brightness offsets according to a difference between the plurality of image brightnesses of the plurality of display areas corresponding to the image data and the plurality of actual backlight brightnesses of the previous image data. 如請求項6所述之亮度補償方法，其另包含有：以該複數個背光亮度偏移對前一影像資料之複數個背光亮度補償，以控制該複數個背光源以該複數個背光亮度開啟。The brightness compensation method of claim 6, further comprising: performing a plurality of backlight brightness compensations on the previous image data by the plurality of backlight brightness offsets to control the plurality of backlights to be turned on by the plurality of backlight brightnesses; . 如請求項6所述之亮度補償方法，其另包含有：於計算該複數個影像亮度與該前一影像資料之該複數個實際背光亮度之差前，正規化(normalize)該前一影像資料之該複數個實際背光亮度。The brightness compensation method of claim 6, further comprising: normalizing the previous image data before calculating a difference between the plurality of image brightnesses and the plurality of actual backlight brightnesses of the previous image data. The plurality of actual backlight brightnesses. 一種區域調光(local dimming)電路，用於一液晶顯示器(liquid crystal display，LCD)中，耦接於一時序控制器及一背光驅動電路，用來接收一影像資料，並執行如請求項1所述之亮度補償方法。A local dimming circuit is used in a liquid crystal display (LCD) coupled to a timing controller and a backlight driving circuit for receiving an image data and executing the request item 1 The brightness compensation method described above. 一種液晶顯示器(liquid crystal display，LCD)包含有：一液晶螢幕，具有複數個顯示區域；複數個背光源，對應於該複數個顯示區域；一背光驅動電路，用來控制該複數個背光源以複數個背光亮度開啟；一時序控制器，用來接收具有複數個補償影像亮度之一補償影像資料；以及一區域調光(local dimming)電路，用來接收一影像資料，並執行如請求項1所述之亮度補償方法。A liquid crystal display (LCD) includes: a liquid crystal screen having a plurality of display areas; a plurality of backlights corresponding to the plurality of display areas; and a backlight driving circuit for controlling the plurality of backlights a plurality of backlights are turned on; a timing controller is configured to receive one of a plurality of compensated image brightness compensation image data; and a local dimming circuit for receiving an image data and performing the request item 1 The brightness compensation method described above.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103778899A (en) * 2014-02-28 2014-05-07 帝豪电子（扬州）有限公司 Dynamic dimming method of liquid crystal display LED backlight
TWI612814B (en) * 2016-11-21 2018-01-21 瑞軒科技股份有限公司 Method for adjusting display parameters

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103778899A (en) * 2014-02-28 2014-05-07 帝豪电子（扬州）有限公司 Dynamic dimming method of liquid crystal display LED backlight
CN103778899B (en) * 2014-02-28 2016-08-24 帝豪电子（扬州）有限公司 A kind of liquid crystal display LED backlight dynamic light adjustment method
TWI612814B (en) * 2016-11-21 2018-01-21 瑞軒科技股份有限公司 Method for adjusting display parameters

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