CAPACITIVE TOUCH CONTROL SWITCH PANELS AND METHOD OF MANUFACTURING THEM

摘要

In a touch control switch panel comprising a dielectric sheet carrying a touch switch which comprises a first touchable electrode on one side of the sheet and second and third mutually separated electrodes on the opposite side of the sheet and in capacitive relation to the first electrode, there are conflicting requirements as to high switch capacitance, small switch area and scratch and impact resistant dielectric sheet. This difficulty is remedied by forming the dielectric sheet of glass which has been chemically tempered and by constituting at least one electrode by a coating deposited on the sheet. The electrode is preferably a tin oxide or indium oxide coating while the electrodes are preferably of conductive enamel. The dielectric sheet may be provided with an opaque coating layer and/or bonded to a backing support e.g. of synthetic plastics material.