A foil-type switching element comprises a first carrier foil and a second carrier foil arranged at a certain distance from each other by means of a spacer, said spacer comprising at least one recess defining an active area of the switching element. At least two electrodes are arranged in the active area of the switching element between said first and second carrier foils in such a way that, in response to a pressure acting on the active area of the switching element, the first and second carrier foils are pressed together against the reaction force of the elastic carrier foils and an electrical contact is established between the at least two electrodes. According to the invention, at least one of said carrier foils comprises a multi-layered configuration with at least two layers of different materials.

An dispersion electroluminescent device and a switch unit using the same are disclosed. The dispersion electroluminescent device includes three electrodes: first and second electrode layers and a common electrode layer. The common electrode layer is disposed between the first and second electrode layers. An electroluminescent layer and a first dielectric layer are disposed between the first electrode layer and the common electrode layer. A second dielectric layer is disposed between the common electrode layer and the second electrode layer. A voltage source applies first and second ac or dc pulse voltages, which are 180° out of phase with each other, across the first electrode layer and the common electrode layer and across the common electrode layer and the second electrode layer, respectively, for canceling mechanical vibrations produced at the first and second dielectric layers by each other.

Eine Folienschalter-Baugruppe ist aus einem Gehäuse und aus einem eine Designfolie, eine Abstandsfolie und mindestens eine weitere Folie umfassenden Folienschalter aufgebaut.

Eine Oberflächenseite des Gehäuses weist eine erste Aussparung zur Aufnahme der Designfolie und der Abstandsfolie des Folienschalters auf, innerhalb der ersten Aussparung ist eine zweite Aussparung mit einer größeren Tiefe zur Aufnahme der weiteren Folie(n) des Folienschalters vorgesehen. Die weitere(n) Folie(n) ist (sind) bündig in die zweite Aussparung eingelegt, die Designfolie und die Abstandsfolie sind mit der Oberfläche des Gehäuses verklebt.

A portable personal computer includes a housing 1 having a mounting portion (10). A keyboard unit (12) is removably mounted on the mounting portion. The keyboard unit includes a planer keyboard body (14) made of synthetic resin, a large number of keys (15) arranged substantially over the whole top face of the keyboard body, a file member (16) put on the underside of the keyboard body, and a shielding plate (17) fixed to the underside of the film member. A keyboard frame (13) is fitted on the peripheral edge portion of the keyboard body and fitted to the mounting portion of the housing. The keyboard body has fixing portions (18) protruding form the underside thereof to extend through the film member and the shielding plate. The fixing portions are fixed to the bottom wall (2a) of the housing by screws (22).

Zum Schutz gegen elektromagnetische Störstrahlung und elektro­statische Entladung besteht das Unterteil (1) des Gehäuses aus Metall, das Oberteil (2) aus einer Leiterplatte, deren Leiter­bild (6) sich auf der Innenfläche befindet, während die Ober­fläche einen durchgehenden Metallbelag (5) aufweist, der mit dem Gehäuseunterteil (1) trennbar kontaktiert ist. In dem Gehäuse sind weitere elektronische Baugruppen (4) angeordnet, die leicht auswechselbar sind, ebenso kann die das Gehäuseober­teil (2) bildende Leiterplatte mit der Tastatur gegen eine andere, beispielsweise eine Folientastatur, leicht ausgewech­selt werden.

Die Erfindung wird angewandt bei Tastaturen für Rechner.

Bei einer Tastatur-Folienschaltung sind Schaltkontaktstellen 2, 4, 6, 8, 10 gruppenweise über Leiterbahnen 1, 3, 5, 7, 9 der Folie 18 zu Anschlusskontaktstellen 13 bis 17 geführt. Um mit einfachen Mitteln eine Unterdrückung der Koppelkapazitäten zu erreichen, sind auf die Folie 18 jeweils zwischen zwei Leiterbahnen 1, 3, 5, 7, 9 Widerstandsbahnen 19 bis 22 aufgedruckt und mit diesen verbunden. Die Widerstandsbahnen 19 bis 22 bestehen aus dem gleichen Kohle-Widerstandsschichtmaterial wie die Anschlusskontaktstellen 13 bis 17 bzw. die Schaltkontaktstellen 2, 4, 6, 8,10.

A keyboard (30), particularly for control of electronics in vehicles, has at least one key (33) mounted in a recess in the keyboard (30) and pivotable about a pivot (51) to press against a shaped portion (67) of a rubber gasket (63) to operate an electrical switch (69). A display (80), preferably a multiple character LCD, for labelling the switch is visible through a transparent member (49) and connected to a p.c.b. by zebra striped members (81, 82). The display (80) ist not obscured by a finger operating the key (33). The key (33) has a transverse bore (54) in which a compression spring is mounted with balls at the end of the spring to co-operate with stepped generally cylindrical members mounted with their axes perpendicular to the pivot pin (51) and forming detent means to give the key (33) a tactile operation. Preferably the key (33) operates three switches (69) by way of three shaped portions (67).

A keyboard (30), particularly for control of electronics in vehicles, has at least one key (33) mounted in a recess in the keyboard (30) and pivotable about a pivot (51) to press against a shaped portion (67) of a rubber gasket (63) to operate an electrical switch (69). A display (80), preferably a multiple character LCD, for labelling the switch is visible through a transparent member (49) and connected to a p.c.b. by zebra striped members (81, 82). The display (80) ist not obscured by a finger operating the key (33). The key (33) has a transverse bore (54) in which a compression spring is mounted with balls at the end of the spring to co-operate with stepped generally cylindrical members mounted with their axes perpendicular to the pivot pin (51) and forming detent means to give the key (33) a tactile operation. Preferably the key (33) operates three switches (69) by way of three shaped portions (67).

Embodiments described herein are directed towards a keypad stiffener and a method for manufacturing. The method may include forming a metal plate form. The metal plate form may include a metal grounding plate, at least one detachable island and at least one bridge. A bridge may mechanically connect the metal grounding plate to the detachable island. The method may also include forming a non-conductive molding mechanically coupling the metal grounding plate and the at least one detachable island and electrically disconnecting the detachable island from the metal grounding plate. Furthermore, subsequent to the electrically disconnecting, the at least one detachable island may be electrically floating with respect to the metal grounding plate.