Method and circuit for controlling the backlighting system of a display apparatus,申请号EP20070108548-传众专利搜索

Method and circuit for controlling the backlighting system of a display apparatus

申请公布号：EP1863008(A3)

申请号：EP20070108548

申请日期：2007.05.21

申请公布日期：2009.07.01

申请人：

THOMSON LICENSING

发明人：PLOQUIN, DIDIER;MACHAND, PHILIPPE;MORIZOT, GERARD

分类号：G09G3/34

主分类号：G09G3/34

摘要：In a display device images are reproduced by controlling the amount of light provided by a light source by means of light modulators for individual pixels. Subsequent images are synchronised to each other by synchronisation signals (VB) regularly occurring at intervals corresponding to first time periods. The backlight is controlled to emit light during fractions of second time periods or whole second time periods which are equal to or shorter than first time periods. Several of the second time periods may be nested and evenly distributed within the first time period. The signals for driving the backlight are preferably generated in synchronism with the horizontal pixel clock. Each of the fractions of second time periods or whole second time periods during which light is emitted is divided into a number of elementary steps, wherein each elementary step corresponds to a number of pixel clock periods. The number of elementary steps is chosen according to the desired ratio of control of the backlight or contrast ratio, e.g. 100 elementary steps for a contrast ratio of 1:100. During each of the second time periods the backlight is controlled to be on for a number of elementary steps corresponding to the desired contrast ratio.