Sensor grid for an electromagnetic digitizer tablet
First Claim
1. A digitizer tablet comprising a fixed array of inductors for use with an external moveable inductor and including means for determining a magnitude of a mutual inductance between the array of inductors and the moveable inductor, wherein the array of inductors is comprised of an x-axis array and a y-axis array, and wherein the x-axis array and the y-axis array are each comprised of a plurality of coil pairs, individual coils of each of the coil pairs being differentially connected one to another.
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Accused Products
Abstract
A digitizer tablet (10) having an array of conductors that define a sensing plane (12) for sensing an electromagnetic signal generated by a pointing device (16) disposed external to the plane. The tablet includes circuitry, coupled to the array of conductors, for determining a magnitude of an electrical signal or signals induced within the array of conductors by the pointing device. The tablet also includes a data processor (30) that is responsive to the determined magnitude for accurately estimating both a position and an angular orientation of the pointing device relative to a coordinate system associated with the sensing plane. The array of conductors is comprised of an x-axis sensor array (14a) and a y-axis sensor array (14b). Each sensor array includes a plurality of differentially interconnected and overlapping coil pairs. Each coil of a coil pair includes a major loop having auxiliary loops coupled to each end thereof for compensating for unmeasured magnetic fields beyond an end of the coil.
124 Citations
44 Claims
- 1. A digitizer tablet comprising a fixed array of inductors for use with an external moveable inductor and including means for determining a magnitude of a mutual inductance between the array of inductors and the moveable inductor, wherein the array of inductors is comprised of an x-axis array and a y-axis array, and wherein the x-axis array and the y-axis array are each comprised of a plurality of coil pairs, individual coils of each of the coil pairs being differentially connected one to another.
- 17. An array of inductors for use in a digitizer tablet, the array of inductors being disposed in a plane and defining an active area wherein a mutual inductance is sensed between the array of inductors and a moveable inductor, wherein the array of inductors is comprised of a first array defining an x-axis array and a second array defining a y-axis array, and wherein the x-axis array and the y-axis array are each comprised of a plurality of coils, wherein each coil includes a major loop having a first end, the first end having a first plurality of auxiliary loops coupled thereto, and a second, opposing end having a second plurality of auxiliary loops coupled thereto.
- 34. An array of conductors for use in a digitizer tablet, the array of conductors being comprised of a first array of coils defining an x-axis array and a second array of coils defining a y-axis array, wherein the coils of the x-axis array and the y-axis array are defined in part by electrically conductive patterns embedded within an insulating matrix, the matrix being disposed upon a first surface of a substrate, and wherein the first surface of the substrate includes electrically conductive regions formed thereon, the regions being conductively coupled to the electrically conductive patterns.
- 41. An array of conductors for use in a digitizer tablet, said array being comprised of a plurality of coil pairs disposed over a surface of a substrate, individual coils of each of the coil pairs being differentially connected one to another.
Specification