| 摘要 |
PURPOSE: To shorten the time of data access to a map memory. CONSTITUTION: A map is divided longitudinally and laterally by meshes to generate and store map data, which are read out in one direction of an array of meshes. A finite number of successive meshes which are arranged in one direction are set as one block (solid-line frame C4 ) and the data are acquired while the finite number of meshes are shifted like a staircase in the same direction as the moving direction (arrow T) of a map display. Consequently, after the read of map data is made continuous as many times as a certain finite frequency, map data of a next area can be obtained thereafter by only single- time access. |
