Noise-canceling system for a digitizing tablet
US4736073A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 10, 1986 |
| Grant date | Apr 5, 1988 |
| Priority date | — |
| Expiry date | Feb 10, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/046
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A digitizing tablet (10) has common return lines (24, 25, 26, and 27) that tend to suppress sensing of the spurious signals induced in them when the digitizer probe (12) approaches the edge of a digitizing area (14). Each return line includes a connection segment (36) and a compensation segment (40), which extend in antiparallel along the edge of the digitizing area (14). The compensation segment (40) is spaced farther from the digitizing area than the connection segment (36) is so that it is only half as sensitive as the connection segment to probe signals. However, since only half of the emf induced in the connection segment (36) is coupled to the circuitry (22) for processing the induced signals, the signals induced in the return lines tend to cancel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.