Patent · US Expired

Navigation apparatus with non-volatile memory for return to initial departure point

US5231584A · kind A · utility

124Cited by
7References
8Claims
0Family size

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Inventors

Key dates

Filing dateSep 16, 1991
Grant dateJul 27, 1993
Priority date
Expiry dateSep 16, 2011

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01C21/34
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A navigation apparatus has an input unit (1), a CPU (2), a display unit (3) and a memory unit (4), the memory unit (4) being a memory such as a CD-ROM in which network data of geographical points, namely destinations and present locations, and information are stored in advance. Also stored are map data (10), an intersection list (11), a destination list (12), road data (13) and a region name list (14), etc. When a destination is designated by an input from the input means (1), the CPU (2) performs an exchange with a program, stored in a ROM (9a), in order to set information for travel to the destination by course exploration in accordance with each geographical point stored in the memory unit (4). This information is stored in a memory such as a RAM (9b). In an embodiment, the RAM (9b) is provided with a non-volatile area for storing departure-point data (east longitude, north latitude, etc.). When an input is made by a reset switch in entering a departure point, the data in this non-volatile area can be rewritten. Data written in are preserved until the reset switch is pressed again and a geographical point is entered. Data will not be erased even if an ignition switch is turned o…

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