Thin keyboard having torsion bar keyswitch hinge members

Abstract

A keyboard apparatus is provided for small and lightweight computers and the like. Keyswitches and a keyboard assembly comprise a sheet member having a plurality of key faces fixed thereon in a conventional keyboard arrangement. A plurality of cutouts are provided in the sheet member, partially surrounding each key face. A living hinge member is provided in the sheet member at one side of each key face. Each living hinge member includes a base section, an intermediate section, and a key face section. The former two and the latter two sections each interface at a living hinge. Depressing the key face causes the key face section to pivot about the living hinges to operate a corresponding set of electrical contacts, indicating operation of the key. A conventional rubber spring may transmit the pivot motion of the key face to the electrical contacts. The living hinges are made to have a greater resilience and flexibility than those of the sections, such as by scoring, scribing, perforation, or other suitable treatment. Accordingly, the intermediate section is able to serve as a torsion bar, advantageously limiting the key's freedom to twist under the user's finger pressulr.