Abstract: A cordless transducer/cursor having a transmitter for use in conjunction with the receiver of a digitizer tablet. The transmitter receives parallel binary signals representing the status of non-positional functions such as command button status and the pressure applied to a stylus of the transducer/cursor and converts these into a serial stream of binary data for electrostatic or electromagnetic transmission to the receiver which, in turn, converts the serial stream into a plurality of parallel binary signals consistent with those received and converted by the transmitter.

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.