Keyboards with matrix of pushbutton keys e.g. for telephones and portable computers

摘要

A keyboard is formed with a matrix of X and Y direction conductor tracks that have points of crossover where the tracks can be brought into contact. One set of tracks are formed on the surface of a base plate (15) and the others are at right angles with a section raised (11) by a deformable bubble section (12). Switched interconnection of one or more matrix points is made by operating a push button (13) that is of insulating material and has projecting actuator fingers that contact and deflect the bubbles. The push button is returned by springs (17).