Browse Prior Art Database

Positive Action Keyboard

IP.com Disclosure Number: IPCOM000081207D
Original Publication Date: 1974-Apr-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Harris, RH: AUTHOR

Abstract

Fig. 1 illustrates a keyboard design which does away with the requirement for an expensive printed-circuit (PC) board. In Fig. 1, a base 1 which supports the elements is made of plastic or other suitable nonconductive material and has laid on it in a crossed matrix configuration, column contact strip or strips 2 and row contact strip or strips 3, which overlie one another at one or more crosspoints.

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Positive Action Keyboard

Fig. 1 illustrates a keyboard design which does away with the requirement for an expensive printed-circuit (PC) board. In Fig. 1, a base 1 which supports the elements is made of plastic or other suitable nonconductive material and has laid on it in a crossed matrix configuration, column contact strip or strips 2 and row contact strip or strips 3, which overlie one another at one or more crosspoints.

An insulative film 4 overlies the conductors 2 and 3, or alternatively, may overlie the arched return spring 5. Arched return spring 5 biases key button 6 in the upward direction, which is held centered over the crossed conductors 3 and 2 by a frame 7. Return spring 5 has an aperture 8 which fits over protrusions 9 from base 1, to maintain the return spring 5 in its proper lateral position. Fig. 2 illustrates an exploded isometric view of a keyboard comprising a plurality of structures such as shown in Fig. 1, in which the shield or film 4 is overlying the return spring 5 as well as contact strips 2 and 3.

Fig. 3 illustrates in enlarged form, a single segment of the arched section of a return spring 5 having apertures 8 and two 45 Degrees angle formed sections at either end of the arch. This arched section of the spring 5 provides a nonlinear force/deflection characteristic and provides a tactile feel. This section alone can perform the return and actuation functions of the keyboard, however, the key force would be high and the key travel low, on the order of about 160 grams and
0.025 inch, respectively.

To increase key travel and to reduce the load required, two 45 Degress angle forms at each end of the arch sectio...