H - Electricity – 03 – M
Patent
H - Electricity
03
M
340/178
H03M 11/00 (2006.01) H03K 17/975 (2006.01)
Patent
CA 1214238
CAPACITIVE KEYSWITCH Abstract of the Disclosure A capacitive membrane keyboard is described which has an upper flexible membrane with a first pattern of interconnecting conductive areas deposited on it at each key station of the key- board. A second pattern of interconnecting conductive areas are deposited on a substrate below the first pattern. At each key station the conductive lands are aligned with each other. An electrically insulating spacer separates the pair of conductive lands at each key station when the keyswitch is unactuated. In one embodiment of the keyboard a dielectric film layer lays over all of the bottom conductive land areas and over the entire lower second circuit pattern. In another embodiment, a dielectric layer is deposited on at least one of the conductive lands at each key station which consists of a polymer dielectric film or other suitable dielectric coating. In still a further embodiment, the lower and upper conductive areas may be made of an oxidizable metal, such as aluminum or tantalum, which has its surface oxidized in an oxidizing atmosphere to form a thin insulating dielectric layer on one or both of the lands of each key station. An elastomeric cushion may rest on top of the upper membrane so that when the actuator of the keyswitch is depressed it will cushion the force of the actuator so as to protect the upper membrane and may provide some return bias force. - 1 -
410276
Illinois Tool Works Inc.
Meredith & Finlayson
LandOfFree
Capacitive keyswitch does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Capacitive keyswitch, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Capacitive keyswitch will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-1254016