| 摘要 |
PROBLEM TO BE SOLVED: To provide a navigation device properly performing switching between the daytime and nighttime screens. SOLUTION: When the present time belongs to a predetermined nighttime period, the nighttime screen is displayed. When an acquired present time belongs to a predetermined daytime period, brightness is acquired from an illuminance sensor 23. When the brightness is equal to or more than a predetermined threshold value, the daytime screen is displayed. When the brightness is equal to or less than the predetermined threshold value, and also located in a place where it is clear that the vehicle environment is dark, such as the inside of a tunnel, based on the current position of the vehicle and map data, the nighttime screen is displayed. Otherwise the daytime screen is displayed. When passing through a short tunnel, or running on a road connecting tunnels, the screen is not switched. COPYRIGHT: (C)2010,JPO&INPIT |
