201015509 九、發明說明： 【發明所屬之技術領域】 本發明是有關於一種顯示器的保護方法，特別是指一 種顯示器的螢幕保護方法。 【先前技術】 現今所普遍使用的顯示器大致可分為陰極射線管顯示 器（Cathode Ray Tube，CRT)、液晶顯示器（Liquid Crystal Display，LCD)及電漿顯示器（Plasma Display Panel，PDP)， O 其中，液晶顯示器中的主動矩陣型之薄模式電晶體型（Thin201015509 IX. Description of the Invention: [Technical Field] The present invention relates to a method of protecting a display, and more particularly to a screen protection method for a display. [Prior Art] The displays commonly used today can be roughly classified into a cathode ray tube display (CRT), a liquid crystal display (LCD), and a plasma display panel (PDP), where Active matrix type thin mode transistor type in liquid crystal display (Thin
Film Transistor，TFT)為現今顯示器的主流產品。而液晶顯 示器是利用電壓導致液晶的轉動而遮蔽背光源的光線來顯 示各種灰階（scale)，但是，顯示器長期固定於同一畫面時， 液晶會長期接受同一電壓的驅動而導致液晶物理特性的改 變，使得當該電壓解除後，液晶將無法正常的轉向而出現 殘影（image sticking)的問題。 若液晶顯示器被應用於安全監控的用途時，顯示器可 ® 能需要24小時持續工作，且長時間監控同一目標或是同一 地方，如此一來，液晶顯示器發生殘影現象的機會相對增 加，且殘影的出現亦會對晝面的判讀造成困難，因此，顯 示器必須適當的使用螢幕保護程式以被動的方式克服殘影 的問題，但傳統的螢幕保護程式被啟動時會切換至一螢幕 保護畫面而使原先的監控晝面無法顯示，並不適合應用在 做為安全監控的顯示器上。 【發明内容】 201015509 口此本發明之目的，即在提供一種可以避免顯示器 螢幕發生殘影現象的顯示器驅動裝置。 於疋，本發明顯示器驅動裝置，用以驅動與一顯示器 面板連接的複數條掃描線，並包含—計時器及_控制電路 其中，计時器在顯示器面板顯示畫面時開始計時，且當 。十時器所计數的時間達到—預設時間時，控制電路會輪流 輸出一反差訊號至每一條掃描線。 地控制電路疋以低速的方式依序輸出反差訊號 至每-條掃描線’且反差訊號為—可使顯示畫面出現一條 純黑色的橫條的訊號。 本發明之另一目的，即在提供一種可以避免顯示器螢 幕發生殘影現象的顯示器螢幕保護方法。 於是，本發明顯示器螢幕保護方法，應用於一顯示器 驅動裝置’該顯示器驅動裝置用以驅動一顯示器面板連接 的複數條掃描線，該顯示器螢幕保護方法包含： 步驟η貞測顯示器面板是否持續顯示畫面時 間’若是則執行步驟b; 步驟b:令顯示器驅動裝置輪流輸出一反差訊號至每一 條掃描線。 較佳地’控制電路是以低速的方式依序輸出反差訊號 母一條掃描線，且反差訊號為—可使顯示畫面出現_條 純黑色的橫條的訊號。 、 本發明之功效在於，防止液晶因為長時間接受同一電 壓的驅動而改變特性，進而造成殘影的問題。 201015509 【實施方式】 有關本發明之前述及其他技術内容、特點與功效，在 以下配合參考圖式之一個較佳實施例的詳細說明中，將可 清楚的呈現。 參閱圖1，為本發明顯示器驅動裝置之較佳實施例，該 顯示器驅動裝置1用以驅動與一液晶顯示器面板2連接的N 條掃描線，其主要應用於安全監控用途的液晶顯示器3中 ，該顯不器驅動裝置1包含一計時器u及一控制電路12〇 配合參閱圖2,為本發.明顯示器螢幕保護方法，首先，步驟 50，計時器11在液晶顯示器面板2顯示畫面時開始計時， 再者，步驟5卜控制電路12會偵測液晶顯示器面板2是否 持續顯示晝面達一預設時間，若是則執行步驟52。在本實 施例中，控制電路12為—螢幕選單顯示晶片（〇n Screen Display，0SD)且該預設時間設定為一小時，換言之當液 晶顯示器面板2持續顯示畫面達一小時時，控制電路12會 執行步驟52 ’輪流輸出—可以使液晶顯示器面板2中的液 晶轉向的反差訊號至每_條掃描線。當然，本實施例之預 設時間是設定為-何，但是料者可以依不同需求和應 用而改變其預設時間，並不以一小時為限。 由於液晶顯不器面板2長時間顯示同一畫面時，會使 得其中的液晶長期接受同—電壓的驅動而導致其物理特性 的改變，因此，控制電路12會每隔一段時間（預設時間）就 輸出-反差訊號至液晶顯示器面2使液晶轉向，在本實 施例中’液晶顯示器面板2為NB(N()rmaUy Β1_的形式， 201015509 且控制電路12所輸出的反差訊號為一接地電壓（〇v)，亦即 接收反差訊號的掃描線所驅動的液晶會被關閉，也就是說 ，反差訊號會強迫每一條掃描線所掃描之液晶顯示器面板2 中對應的一列液晶轉向，使得該液晶顯示器面板2的畫面 上會出現一條由上到下依序移動的黑色橫條紋（bar)，使液 晶不會因為長期接受同一電壓的驅動而改變特性。 反之’若液晶顯示器面板2為NW(Normally White)的 形式，反差訊號則會使液晶顯示器面板2的畫面上會出現 一條由上到下依序移動的白色橫條紋（bar)，也就是說反⑩ 差訊號可以為任何電壓，只要能使液晶達到轉向而避免長 時間由同-電壓驅動即可，故不以本實施例為限。 值得一提的是，控制電路12是將反差訊號取代在原本 就具有顯示資料的掃描線上，換言之’反差訊號會蓋掉原 本的顯示資料而使得在顯示畫面中出現一條黑色的橫條， 再者控制電路12 -次只會對—條掃描線輸出反差訊號， 故其餘的掃描線仍然會傳送原本的顯示資料至液晶顯示器 面板2。此外，控制電路12會從第一條掃描線開始，以較❹ 低的速度（例如：6ms)依序將反差訊號輸出至每一條掃描線 ’因此’使用者可以從顯示畫面上看到一條水平的黑色條 紋：從上到下的掃描整個畫面。當然，控制電路Η亦可以 人輸出反差訊號給多個掃描線或是全部的掃描線，且輸 出的順序也可以從第N條掃描線到第—條掃描線（即從下到 的掃描整個畫面），或是左右掃描整個畫面還可以是以 隔條的方式輪流輸出反差訊號。 201015509 ❹ 控制電路12以低速輸出反差訊號的原因在於可以給 液晶足夠的轉向及回復的時間，以避免出現因液晶的雜 改變而產生殘影（image stieking)㈣題，再者，不同面板廠 商所生產製造的液晶的反轉及回復時間不盡相同，因此， 控制電路12輸出反^訊號至卜條掃描線的時間只要大 於液晶的反轉及回復時間即可，故不以上述“為限。 田控制電路12將反差訊號輸出至每一條掃描線後，顯 示器驅動裳置！中的計時器會重新計時，且重複執行步驟 5〇〜52，直到液晶顯示器3關閉或是液晶顯示器面板2不再 輸出晝面為止。 ❹ 本實施例之顯示器螢幕保護方法主要是針對液晶顯示 器3的螢幕加以保護，但是陰極射線管顯示器(Cathode Ray ㈣，CRT)及電漿顯示器_嶋吻心，pDp)仍缺 可以使用該保護方法來取代現有的螢幕保護程式，以避免 顯不器因為長時間顯示同一畫面而產生殘影等相關問題。 综上所述，本發明顯示器驅動裳置i會每隔一段時間 蚀反差訊號至液晶顯示器面板2的每一條掃描線， 付其中的液晶可以在該時間内至少被轉向一次，使液晶 不會因為長時間接受同一電壓的驅動而改變特性，進而避 免造成殘影的問題。 惟以上所述者，僅為本發明之較佳實施例而已，者不 ==本發明實施之範圍’即大凡依本發明申請專利 ^及發明說明内容所作之簡單的等效變化與修飾，皆仍 屬本發明專利涵蓋之範圍内。 9 201015509 【圖式簡單說明】 圖1是一電路方塊圖，說明本發明顯示器驅動裝置之 較佳實施例；及 圖2是一流程圖，說明本發明顯示器螢幕保護方法。Film Transistor (TFT) is the mainstream product of today's displays. The liquid crystal display uses various voltages to cause the liquid crystal to rotate and shield the backlight to display various gray scales. However, when the display is fixed on the same screen for a long time, the liquid crystal will be driven by the same voltage for a long time, resulting in a change in the physical properties of the liquid crystal. Therefore, when the voltage is released, the liquid crystal will not be able to turn normally and the problem of image sticking occurs. If the liquid crystal display is used for safety monitoring purposes, the display can work continuously for 24 hours, and monitor the same target or the same place for a long time. As a result, the chance of image sticking of the liquid crystal display is relatively increased, and the residual The appearance of shadows will also cause difficulties in the interpretation of the face. Therefore, the monitor must properly use the screen saver to passively overcome the problem of image sticking, but the traditional screen saver will switch to a screen saver when it is activated. The original monitoring surface cannot be displayed and is not suitable for use as a display for security monitoring. SUMMARY OF THE INVENTION The object of the present invention is to provide a display driving device capable of avoiding image sticking on a display screen. In the present invention, the display driving device of the present invention is configured to drive a plurality of scanning lines connected to a display panel, and includes a timer and a control circuit, wherein the timer starts counting when the display panel displays a picture, and when. When the time counted by the chronograph reaches - the preset time, the control circuit will alternately output a contrast signal to each scan line. The ground control circuit sequentially outputs the contrast signal to each of the scanning lines ' at a low speed and the contrast signal is - to cause a pure black horizontal bar signal to appear on the display screen. Another object of the present invention is to provide a display screen protection method that can avoid image sticking of a display screen. Therefore, the display screen protection method of the present invention is applied to a display driving device for driving a plurality of scanning lines connected to a display panel. The display screen protection method comprises: step η detecting whether the display panel continues to display a screen Time 'if yes, step b is performed; step b: causing the display driving device to alternately output a contrast signal to each scanning line. Preferably, the control circuit sequentially outputs a contrast signal to the scanning line in a low-speed manner, and the contrast signal is - a signal that causes a pure black horizontal strip to appear on the display screen. The effect of the present invention is to prevent the liquid crystal from changing characteristics due to driving for the same voltage for a long time, thereby causing a problem of image sticking. The above and other technical contents, features and effects of the present invention will be apparent from the following detailed description of the preferred embodiments. 1 is a preferred embodiment of a display driving device of the present invention. The display driving device 1 is configured to drive N scanning lines connected to a liquid crystal display panel 2, and is mainly used in a liquid crystal display 3 for security monitoring purposes. The display device 1 includes a timer u and a control circuit 12. Referring to FIG. 2, the display screen protection method of the present invention is first. In step 50, the timer 11 starts when the liquid crystal display panel 2 displays a screen. Timing, in addition, step 5 control circuit 12 will detect whether the liquid crystal display panel 2 continues to display the surface for a preset time, and if so, step 52 is performed. In this embodiment, the control circuit 12 is a screen display display (0SD) and the preset time is set to one hour. In other words, when the liquid crystal display panel 2 continues to display the image for one hour, the control circuit 12 Step 52 'rotation output' is performed - the contrast signal of the liquid crystal in the liquid crystal display panel 2 can be turned to every scan line. Of course, the preset time of this embodiment is set to -, but the user can change the preset time according to different needs and applications, and is not limited to one hour. Since the liquid crystal display panel 2 displays the same picture for a long time, the liquid crystal therein is subjected to the same-voltage driving for a long time, resulting in a change in its physical characteristics. Therefore, the control circuit 12 will be at intervals (preset time). The output-contrast signal to the liquid crystal display surface 2 turns the liquid crystal. In the embodiment, the liquid crystal display panel 2 is in the form of NB (N()rmaUy Β1_, 201015509 and the contrast signal outputted by the control circuit 12 is a ground voltage ( 〇v), that is, the liquid crystal driven by the scanning line receiving the contrast signal is turned off, that is, the contrast signal forces each column of the liquid crystal display panel 2 scanned by each scanning line to turn, so that the liquid crystal display A black horizontal stripe (bar) moving from top to bottom appears on the screen of panel 2, so that the liquid crystal will not change its characteristics because it is driven by the same voltage for a long time. Conversely, if LCD panel 2 is NW (Normally White) In the form of a contrast signal, a white horizontal stripe moving sequentially from top to bottom appears on the screen of the liquid crystal display panel 2 (b) Ar), that is to say, the inverse 10 difference signal can be any voltage, as long as the liquid crystal can be turned to avoid long-term driving by the same voltage, so it is not limited to this embodiment. It is worth mentioning that the control circuit 12 is to replace the contrast signal on the scan line that originally has the display data. In other words, the 'contrast signal will cover the original display data, so that a black horizontal bar appears in the display screen, and then the control circuit 12 will only be The scanning line outputs a contrast signal, so the remaining scanning lines will still transmit the original display data to the liquid crystal display panel 2. In addition, the control circuit 12 will start from the first scanning line at a relatively low speed (for example: 6ms). ) Output the contrast signal to each scan line in sequence. Therefore, the user can see a horizontal black stripe from the display screen: scan the entire screen from top to bottom. Of course, the control circuit can also output the contrast signal. Give multiple scan lines or all scan lines, and the order of output can also be from the Nth scan line to the first scan line (ie, from bottom to bottom) The screen can be rotated to output the contrast signal in the form of a spacer. 201015509 ❹ The reason why the control circuit 12 outputs the contrast signal at a low speed is that the liquid crystal can be sufficiently turned and recovered to avoid the occurrence of time. The image stieking (4) problem occurs due to the miscellaneous change of the liquid crystal. Furthermore, the reversal and recovery time of the liquid crystal produced by different panel manufacturers are not the same. Therefore, the control circuit 12 outputs the inverse signal to the scan. The time of the line is only greater than the inversion and recovery time of the liquid crystal, so it is not limited to the above. After the field control circuit 12 outputs the contrast signal to each scanning line, the timer in the display drive will be re-timed. And repeat steps 5〇 to 52 until the liquid crystal display 3 is turned off or the liquid crystal display panel 2 is no longer output.显示器 The display screen protection method of the present embodiment mainly protects the screen of the liquid crystal display 3, but the cathode ray tube display (Cathode Ray (4), CRT) and the plasma display _嶋 kiss, pDp) are still missing. It replaces the existing screen saver to avoid problems such as afterimages caused by displaying the same screen for a long time. In summary, the display driving i of the present invention will erode the contrast signal to each scanning line of the liquid crystal display panel 2 at intervals, and the liquid crystal paid therein can be turned at least once during the time, so that the liquid crystal is not caused by The function of changing the same voltage for a long time changes the characteristics, thereby avoiding the problem of image sticking. However, the above is only the preferred embodiment of the present invention, and the present invention is not limited to the scope of the present invention, that is, the simple equivalent changes and modifications made by the present invention and the description of the invention. It is still within the scope of the invention patent. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit block diagram showing a preferred embodiment of a display driving device of the present invention; and FIG. 2 is a flow chart illustrating a display screen protecting method of the present invention.
10 201015509 【主要元件符號說明】 步驟50~52 I ..........顯示器驅動裝置 II .........計時器 12.........控制電路 2 ..........液晶顯示器面板 3 ..........液晶顯不10 201015509 [Explanation of main component symbols] Steps 50~52 I ..........Display drive unit II .... Timer 12.........Control circuit 2 ..........LCD panel 3 ..........
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