Fixed range indicating system for use in a vehicle travel path indicating apparatus

摘要

An improved fixed range or distance indicating system for use in a visual travel route indicating apparatus of a vehicle. The fixed range indicating system minimizes memory capacity by discretely storing locational data obtained from discrete arithmetical calculation made at a suitable predetermined interval to present relatively short vector segments optimized in accordance with the given scale of indication on the display and at the same time provides a relatively high accuracy in approximating a current locational indication of the vehicle. A plurality of basic scales of indication varying with doubled denominators in accordance with a given variety of basic scales of indication are presented, the locational data are picked-up discretely at a rate corresponding to the plurality of basic scales of indication, and the thus picked-up locational data is stored into prescribed memory tables within a given limit of indication by way of an endless store mode. The current indicated path of travel on the display is erased at the interval of a fixed range travelled by the vehicle corresponding to the basic scales of indication, and refreshed points of indication are determined for a new location of the vehicle in accordance with a given scale of indication from the current points of indication for the current location at the time of erasing on the basis of the locational data read out from the memory table.