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Magnetic Induction Keyboard

IP.com Disclosure Number: IPCOM000050526D
Original Publication Date: 1982-Nov-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 63K

Publishing Venue

IBM

Related People

Vinal, AW: AUTHOR

Abstract

An inductive magnetic matrix keyboard is shown in the figures. In Fig. 1, individual key positions for a 12-position matrix are shown. An individual Y winding wire 1 passes out to each XY key position, makes a single loop, and then continues on to the next key position in a given row, as shown. Wire 1 loops back from the last key position in the row, and presents the output 2 as the Y row signal output. The X windings 3 produce an output at 4 in similar fashion. An inherent N key roll capability is present in this design due to the fact that an instantaneous pulse output is simultaneously produced on an X and Y column and row combination that is unique for each key depression and in the sequence of key depressions occurring.

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Magnetic Induction Keyboard

An inductive magnetic matrix keyboard is shown in the figures. In Fig. 1, individual key positions for a 12-position matrix are shown. An individual Y winding wire 1 passes out to each XY key position, makes a single loop, and then continues on to the next key position in a given row, as shown. Wire 1 loops back from the last key position in the row, and presents the output 2 as the Y row signal output. The X windings 3 produce an output at 4 in similar fashion. An inherent N key roll capability is present in this design due to the fact that an instantaneous pulse output is simultaneously produced on an X and Y column and row combination that is unique for each key depression and in the sequence of key depressions occurring.

Turning to Fig. 2, a typical key position for the matrix in Fig. 1 is shown. A key 5 has a stem 6 biased by a compression spring 7 that bears against a dimpled snapping dome of metal, plastic, or the like 8. An insulating circuit board 9 has an aperture 10 in which a sleeve 11 may be inserted, if desired. The individual coils 1 and 3 are shown in cross section, and comprise a single turn for each of the X and Y row and columns. A stem 12 carries two permanently magnetized magnets 13A and 13B with their like poles positioned together. The stem 12 may be made of plastic that is upset or molded to retain the two magnets 13A and 13B in conjunction with one another despite their repulsion force.

The magnet pair 13A and...