Map and calculator device
US5902113A · kind A · utility
11Cited by
5References
8Claims
0Family size
Assignees
Inventors
Key dates
| Filing date | Aug 7, 1997 |
| Grant date | May 11, 1999 |
| Priority date | — |
| Expiry date | Aug 7, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09B29/005
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A map which may also be a calculating or teaching device includes a flat representation of a planet with one hemisphere on one side and the opposite hemisphere on the opposite side. The hemispheres are projected to the same scale with matching meridian lines, an arbitrary point of interest forms the center of one side and the antipode of the point of interest forms the center of the other side. Scales are provided by which great circle routes may be plotted and measured. The maps are preferably conformed to an azimuth equidistant projection. A variation is disclosed by which the change from night and day is delineated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.