Abstract

A hand-controlled mechanism is described for producing signals to move the position of a cursor in a computer display. The mechanism includes a shaft with an elongated axis. A plurality of conductors are wrapped around the shaft and a cylindrical member is mounted for both rotary and lateral movements along the shaft. Signal drivers are provided for applying an energizing signal to a sequence of the conductors. The cylindrical member is provided with conductive plates which overlap a plurality of the conductors, the plates acting to couple an energizing signal applied to one conductor to other conductors which are overlapped by the plates. A decoder senses the coupled energizing signals and provides an output indicative of the position of the cylindrical member to accordingly control a cursor's position. In a preferred embodiment, first and second conductor groups are helically wrapped about the shaft in opposite directions and with orthogonal pitches. By comparing the outputs from conductive plates which are juxtaposed to both wrapped conductor groups, the change of position of the cylindrical member can be accurately determined for cursor control purposes.

Other References

• Leon, "Thumbwheel Positional Control Unit", IBM Techical Disclosure Bulletin, vol. 21, No. 7, Dec. 1978, pp. 3026-302