Patent ID: 8103439

Claim:
A portable navigation terminal that transmits current position information obtained from a GPS system to an information distribution server, receives map information and route information from the information distribution server, and displays a map and a route on a display section, wherein the portable navigation terminal comprises: a speed detecting section for detecting the traveling speed thereof; a map data request/acquisition section for requesting and acquiring different types of map data from the information distribution server depending on the traveling speed detected by the speed detecting section; an auto-scrolling section for maintaining a current position at the center of a display screen by scrolling the map automatically; an operation section including a map stopping button for stopping the change being made in the type of map displayed on the display section at an arbitrary point in time during travel and for stopping the switch to a new map data including the current position even if the current position changes, wherein the map stopping button includes a zoom-in button and a zoom-out button; and a map change prohibition section for inhibiting the process of switching the type of map currently displayed on the display section when the map stopping button is operated; wherein, if the zoom-in button or the zoom-out button is operated during a valid term of the auto-scroll section, the map change prohibition section inhibits the process of switching the map displayed to a map corresponding to the traveling speed detected by the speed detecting section such that the map currently displayed on the display section continues to be displayed without being substituted by another type of map regardless of the traveling speed of the portable navigation terminal and without switching to the new map data including the current position even if the current position changes, and wherein, if the zoom-in button or the zoom-out button is operated during the valid term of the auto-scroll section and during the terminal is actually moving, the auto-scrolling section is made inoperative such that the map currently displayed on the display section continues to be displayed without switching to the new map data including the current position even if the current position changes by the terminal's actual movement.