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Fully Encoded Keyboard Magnetic Sensor

IP.com Disclosure Number: IPCOM000081498D
Original Publication Date: 1974-Jun-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 66K

Publishing Venue

IBM

Related People

Betts, R: AUTHOR [+2]

Abstract

Fig. 1 illustrates a noncoded keyboard array of sensing coils which would be energized by a magnetic actuating device being brought suddenly into proximity with the coils, to induce an electrical voltage signal therein. The key locations are identified within the dotted rectangular areas. It may be seen that each rectangular area contains two sense coils, one in an X row and one in a Y row so that, upon depression of a key actuator, not shown, a signal will be generated uniquely on a single Y and a single X line.

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Fully Encoded Keyboard Magnetic Sensor

Fig. 1 illustrates a noncoded keyboard array of sensing coils which would be energized by a magnetic actuating device being brought suddenly into proximity with the coils, to induce an electrical voltage signal therein. The key locations are identified within the dotted rectangular areas. It may be seen that each rectangular area contains two sense coils, one in an X row and one in a Y row so that, upon depression of a key actuator, not shown, a signal will be generated uniquely on a single Y and a single X line.

The various X and Y coils are connected in series to common return lines for the X return and the Y return. The conductors that connect the coils are mounted on a circuit board 1, with the conductors that are on the underside of the board shown in dotted lines. Two-key roll and N-key roll operation can be obtained from this configuration utilizing typical control logic to either lockout additional signals, after the first key depression to provide two-key roll, or by providing a buffer or similar storage means to store the key signals in order, as they are produced for N-key roll operation.

Fig. 2 illustrates another form of noncoded keyboard, in which the conductor pattern is provided on a single side of a printed-circuit board 1 to transmit individual actuator response signals along the conductor lines, directly to sense- amplifier input terminals at the end of the conductors. This configuration is most practical...