Keyboard

摘要

Keyboard or control panel having a printed-circuit board, a transparent board and keys, consisting of a key housing, a key head and a contact element made of conductive rubber. An opaque frame grid, with openings corresponding to the viewing windows for the individual keys, is printed onto the transparent board. The remaining frame parts contain openings for holding the switch housings. The switch housings are designed on the underside with legs which project into holes in the printed-circuit board so that, on the one hand, the openings in the printed-circuit board lie precisely under the windows in the opaque impression on the transparent board and a sheet placed under the complete arrangement, made visible with the symbols allocated to the keys, is visible through them, and, on the other hand, the contact electrode sets printed on the printed-circuit board lie precisely under the contact elements of the key units, so that the contact element is in each case pressed down onto the associated electrode set of the printed-circuit board by pressing the associated key head, and this key switch can thus be closed. The legs on the key housings are compressed from below onto the printed-circuit board, so that the complete arrangement is assembled firmly to form an integral arrangement. An easy assembly capability is thus provided, even for large-area keyboards, as well as a representation of the key symbols which is separated from the key operation, without the transparency of the viewing windows suffering as a result of the repeated key operation, the symbols becoming illegible or transparent window caps suffering damage even during production which adversely affects the transparency. <IMAGE>