| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a technique for determining whether or not such information that a user wants to see is displayed in a map without making a specified sensor indispensable and, on the basis of the determination result, reducing the power consumption of the image display device in the image display device for displaying the map. <P>SOLUTION: The navigation control apparatus 1, while a vehicle is in running and performs map display, prepares a frequency distribution of luminance Y with respect to pixels of plotting data in a frame buffer, while such a condition that the number of a class in which the frequency in the frequency distribution exceeds the frequency threshold (n) is less than the class number threshold (m) is satisfied, a backlight is put off or is made extinct more than usual and, while the number of class is the class number threshold (m) or more, the backlight is controlled into usual brightness. <P>COPYRIGHT: (C)2011,JPO&INPIT |
