Unit and program for displaying map
US7199800B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 8, 2003 |
| Grant date | Apr 3, 2007 |
| Priority date | — |
| Expiry date | Aug 8, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08G1/0969
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention provides a map display unit including a first memory for storing map data and a drawing memory for drawing the map data and displaying display-area data and a display. The map display unit includes a unit to read and decompress compressed map data stored in blocks in a data storage medium and to store the decompressed map data in the first memory; a unit to draw the stored map data in the drawing memory; and a unit to determine the display area and to display the display-area data of the drawing area in the drawing memory on the display. When there is no display-area data in the first memory, compressed map data is read and decompressed from the data storage medium by the data decompression unit. The map display unit further includes an environmental change sensor and controllers to vary the color tone of the map data with the environmental change, thereby displaying easily viewable map data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.