| 摘要 |
PROBLEM TO BE SOLVED: To provide a navigation system enabling to acquire desired information at a short time and cheap communication link costs and to update the program for displaying the information easily, as well as an information providing server and an information providing system using these. SOLUTION: This navigation system 1 is constituted in such a manner that it is judged whether the memorized information provided to a user is the newest or not, by dividing them into two kinds such as constant information 41 with a long updating cycle and variable information 42 with a short updating cycle and by checking them respectively. If one or more information is found not the newest, the newest information corresponding to at least one of the two kinds of information 41, 42 is acquired by accessing to the information providing server 2. Consequently, since only updating information is acquired from the information providing server 2 in almost all cases, desired information provided to a user is acquirable at a short time and low communication cost. COPYRIGHT: (C)2005,JPO&NCIPI |
