Patent · US Expired

On-board navigation apparatus

US5396430A · kind A · utility

44Cited by
6References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 10, 1992
Grant dateMar 7, 1995
Priority date
Expiry dateMar 10, 2012

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01C21/3667
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

An on-board navigation apparatus is designed to shorten the time for a display operation at the time of displaying a map and scrolling a screen while employing a buffer memory with a smaller memory capacity. The apparatus reads only block data of a block containing a display center point and block data of blocks adjoining thereto and stores the data into a buffer memory, and acquires display data forming a display screen with the display center point as a reference point from the buffer memory and performs a display operation. The reading/storing operation includes an operation of storing the block containing the display center point and blocks adjoining thereto separately into the buffer memory. The display control operation includes an operation of temporarily storing the display data into a display buffer memory before displaying it.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.