Douglas H Seggelin

US Patent:

40138356, Mar 22, 1977

Filed:

Oct 23, 1975

Appl. No.:

5/625240

Inventors:

Joseph J. Eachus - Cambridge MA
Theodore S. Graff - Sudbury MA
Douglas H. Seggelin - Whitman MA

Assignee:

Honeywell Information Systems, Inc. - Waltham MA

International Classification:

G08C 2100

US Classification:

178 18

Abstract:

A novel data entry system is disclosed which comprises both a touch sensitive device and a location identification device. The touch sensitive device includes a printed circuit board arrangement of conductors which define data input locations that are touch sensitive. The locations are touch sensitive by virtue of a layer of variable resistance material disposed over the printed circuit board which is highly conductive when subjected to touch pressure. The electrical conductivity of a touched location is sensed by the location identification device which thereafter provides a digital coding of the location and maintains the same until the touch pressure has been removed. The location identification device moreover prevents the double entry of data due to any variation in the touch pressure.