Texas Instruments Corporation

Raymond K Erickson, Jr

Robert T Bate

W S Henrion

A solid state keyboard comprised of a base module, a plurality of key members each having a plunger member comprised of a uniform mixture of a magnetic material such as barium ferrite and a binder such as nylon, and a respective plurality of improved Hall Effect Generators, provides a significant improvement in performance and cost effectiveness. Actuation of a key member moves its plunger member, which has a preselected magnetic field, relative to an improved Hall Effect Generator, in which offset voltage has been substantially eliminated. This movement exposes the generator to a change in the direction of the magnetic field, thus causing a corresponding change in the output voltage of the generator from a first predetermined voltage to a second predetermined voltage. A unique tripolar magnetic arrangement on the plunger member provides positive switching and better control of switching points.

Solid state keyboard

A semiconductor body has formed on it at least two hall effect plates each having a pair of oppositely positioned current contacts and a pair of oppositely positioned hall voltage contacts, the hall effect plates being positioned with respect to each other such that a line of one bisecting the current terminals is generally orthogonal to a line of the other bisecting the current terminals. Means are provided for applying a voltage across the current terminals of both of the hall plates and means are provided for selectively applying a magnetic field that intersects substantially perpendicularly the plane of the hall plates. The positive hall voltage contacts are connected together and the negative hall voltage contacts are connected together, with output circuitry connected to this interconnecting circuitry for receiving and transmitting an electrical signal indicative of the presence of the intersecting magnetic field.

Growing community of inventors

Missouri City, TX, United States of America

Raymond K Erickson, Jr