US 4,055,735 AGranted

Touch sensitive device

AssigneeHoneywell Information Systems Inc.

InventorsJoseph J. Eachus, Theodore S. Graff

Life of this patent

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Abstract

A touch sensitive device includes an arrangement of conductors in combination with a pressure sensitive electrically conductive material. The conductors appear in a cross-wire matrix imprinted on the top and bottom surfaces of a rigid printed circuit board. The pressure sensitive electrically conductive material is positioned over the cross-wire matrix of spaced electrical conductors. The resulting arrangement defines a plurality of touch sensitive locations which may be used for uniquely entering information in a data entry system.

Claims11

Dependent claims

A touch sensitive device comprising:

a first layer of material having a plurality of denoted locations on a topmost surface;
a second continuous layer of variable resistance flexible material positioned thereunder, said variable resistance flexible material being pressure sensitive so as to normally be high in resistance when not under an externally applied pressure and low in resistance only at a location that has been subjected to externally applied pressure;
and
a third layer comprising a rigid circuit means for defining a plurality of touch sensitive locations said rigid circuit means being positioned underneath said second continuous layer of variable resistance flexible material, said rigid circuit means comprising:
a first plurality of parallel conductors oriented in a first direction and lying in a first surface of said rigid circuit means, each of said first plurality of conductors being in contact with said second continuous layer of variable resistance flexible material;
a second plurality of parallel conductors oriented in a second direction and lying on a second surface of said rigid circuit means;
and
at least one conductive terminal on said first surface for each of said second plurality of conductors, each conductive terminal on said first surface being spaced from a respective conductor lying on the first surface, each conductive terminal on said first surface moreover being in contact with said second continuous layer of variable resistance flexible material, said conductive terminals on said first surface combining with respective conductors lying on said first surface so as to define a plurality of potentially conductive paths through said second continuous layer of variable resistance flexible material said potentially conductive paths thereby defining a plurality of touch sensitive locations located underneath said plurality of denoted locations on the topmost surface of said first layer of material whereby application of a predetermined amount of externally applied pressure to a given denoted location will establish a conductive path thereunder.

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Dependencies are inferred from the claim text.

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Abstract

A touch sensitive device comprising:

a first layer of material having a plurality of denoted locations on a topmost surface;
a second continuous layer of variable resistance flexible material positioned thereunder, said variable resistance flexible material being pressure sensitive so as to normally be high in resistance when not under an externally applied pressure and low in resistance only at a location that has been subjected to externally applied pressure;
and
a third layer comprising a rigid circuit means for defining a plurality of touch sensitive locations said rigid circuit means being positioned underneath said second continuous layer of variable resistance flexible material, said rigid circuit means comprising:
a first plurality of parallel conductors oriented in a first direction and lying in a first surface of said rigid circuit means, each of said first plurality of conductors being in contact with said second continuous layer of variable resistance flexible material;
a second plurality of parallel conductors oriented in a second direction and lying on a second surface of said rigid circuit means;
and
at least one conductive terminal on said first surface for each of said second plurality of conductors, each conductive terminal on said first surface being spaced from a respective conductor lying on the first surface, each conductive terminal on said first surface moreover being in contact with said second continuous layer of variable resistance flexible material, said conductive terminals on said first surface combining with respective conductors lying on said first surface so as to define a plurality of potentially conductive paths through said second continuous layer of variable resistance flexible material said potentially conductive paths thereby defining a plurality of touch sensitive locations located underneath said plurality of denoted locations on the topmost surface of said first layer of material whereby application of a predetermined amount of externally applied pressure to a given denoted location will establish a conductive path thereunder.

5 more elements