Patent ID: 8903642

Claim:
A mobile body position information transmitting device for a navigation system, the transmitting device comprising: a position information acquiring unit adapted to acquire position information indicating a current position of a mobile body; a storing unit adapted to store time information while associating it with the position information; a judging unit adapted to judge whether the current position acquired by the position information acquiring unit is included in an area previously set by a user or not; a transmitting unit adapted to perform the operation of: receiving a request to transmit the position information acquired by the position information acquiring unit from a communication device installed at a roadside, and (a) if the judging unit judges that the current position is not included in the area, further transmitting the position information acquired by the position information acquiring unit and the time information stored in the storing unit and associated with the position information to the communication device, and (b) if the judging unit judges that the current position is included in the area, not further transmitting the position information acquired by the position information acquiring unit and the time information stored in the storing unit and associated with the position information to the communication device; and an area storing unit adapted to store a position of the area; and a time measuring unit adapted to measure an elapsed time from when the mobile body started from the position stored in the area storing unit up to the present, wherein the judging unit further judges whether the elapsed time is longer than a previously set threshold time or not, and the transmitting unit transmits the position information acquired by the position information acquiring unit, if the judging unit judges that the current position is not included in the area and that the elapsed time is longer than the threshold time.