公开(公告)号：US07034895B2

公开(公告)日：2006-04-25

申请号：US10316001

申请日：2002-12-11

申请人： Junichi Okunuki ,  Atsushi Kuroda

发明人： Junichi Okunuki ,  Atsushi Kuroda

IPC分类号： H04N5/14 ,  H04N5/57 ,  H04N5/74

CPC分类号： H04N9/3182 ,  G09G3/3406 ,  G09G2320/0247 ,  G09G2320/0276 ,  G09G2320/0606 ,  G09G2320/0626 ,  G09G2320/066 ,  G09G2360/16 ,  H04N5/63 ,  H04N5/7416

摘要： A light quantity control by a user can be synchronized to an automatic light quantity control depending on a luminance level of an input video signal. An image display apparatus partially passes or reflects a light from a light source which can control light quantity and displays an image based on a video signal externally input, and has a predetermined scope of an output level corresponding to a scope of control of light quantity of the light source, and includes: a light quantity control unit having a predetermined scope of an output level corresponding to the scope of control of the light quantity of the light source, and for outputting a reference signal at a level arbitrarily set by a user; an APL detection circuit for detecting the average luminance level for one frame (or one field) of the video signal, and outputting an amplification coefficient depending on the detected average luminance level; a multiplier circuit for multiplying the amplification coefficient by a reference signal, and outputting a control signal which is the multiplication result; and a power circuit for controlling the light quantity of the light source according to the control signal.