Electro-optical position determining system
US4688933A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 10, 1985 |
| Grant date | Aug 25, 1987 |
| Priority date | — |
| Expiry date | May 10, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/04845
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A position determining system for providing electrical signals representative of the positions of a light source movable within a defined area. The system may be implemented for purposes of data entry or for purposes of object location or surveying. When embodied in a data entry tablet, the invention provides signals representative of the positions of a stylus movable within the area of the tablet and comprising first and second photodetectors spaced along a base line by a predetermined distance, and means associated with each photodetector and operative to provide a movable narrow field of view for each photodetector. Means are provided for monitoring the angular position of each of the fields of view with respect to the base line and for providing a signal indication of the respective angular positions. A stylus having a light emitter at the tip thereof is movable within the area of the tablet and provides light detachable by each of the photodetectors. Each of the photodetectors provides a respective signal when the field of view of the corresponding photodetector receives light from the emitter. Means are provided which are operative in response to the signal indication of the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.