| 摘要 |
PROBLEM TO BE SOLVED: To shorten the time from turning-on of power supply to indicating of a present position. SOLUTION: When a navigation system 1 is in a static state and is mounted on a cradle 4, a terrestrial magnetism value TM, position information PS, and directional information DR are stored in the system by an environmental information processing section 13; when the power supply is turned on from an operation halt to start, the system is fitted to a cradle 4; when the system in a static state and a difference between the terrestrial magnetism value TM stored in a memory section 13 and the current terrestrial magnetism value TM is less than a predetermined value, it is judged that the surrounding environment is not changed; the position information PS and the directional information DR that have been stored in the memory section 13 before the power supply is turned off, are restored as the current position information PS and the directional information DR; thus, the current position can be recognized immediately after the power supply is turned on; as a result, a map screen and a route guiding screen corresponding to the current position can be presented. COPYRIGHT: (C)2008,JPO&INPIT |
