Low-power electromagnetic digitizer tablet
First Claim
Patent Images
1. A electromagnetic digitizer tablet comprising an electrode array under an active tablet area and a pointing device having an inductor which when energized when the pointing device is over the electrode array will electromagnetically induce electrical signals in the array, the improvement comprising:
- (a) said electrode array comprising a plurality of triangular-shaped electrodes distributed side-by-side underneath the active tablet area such that the apices of adjacent triangular-shaped electrodes lie adjacent opposite sides of the active tablet area,(b) means connected to each electrode for determining the electrical signal induced in each triangular-shaped electrode,(c) means for locating the pointing device inductor position relative to the electrode array based upon the signal levels induced in each electrode of the array.
4 Assignments
0 Petitions
Accused Products
Abstract
A low-power electromagnetic digitizer table employing triangular-shaped electrodes arrayed in a single plane. A pointing device coil when energized induces signal voltages in the electrodes underneath. The electrodes are scanned in timed relation, and the induced voltages digitized and compared to determine the X/Y coordinates of the pointing device with respect to the electrode array.
52 Citations
10 Claims
-
1. A electromagnetic digitizer tablet comprising an electrode array under an active tablet area and a pointing device having an inductor which when energized when the pointing device is over the electrode array will electromagnetically induce electrical signals in the array, the improvement comprising:
-
(a) said electrode array comprising a plurality of triangular-shaped electrodes distributed side-by-side underneath the active tablet area such that the apices of adjacent triangular-shaped electrodes lie adjacent opposite sides of the active tablet area, (b) means connected to each electrode for determining the electrical signal induced in each triangular-shaped electrode, (c) means for locating the pointing device inductor position relative to the electrode array based upon the signal levels induced in each electrode of the array. - View Dependent Claims (2, 3)
-
-
4. A electromagnetic digitizer tablet comprising an electrode array under an active tablet area and a pointing device having an inductor which when energized when the pointing device is over the electrode array will electromagnetically induce electrical signals in the array, the improvement comprising:
-
(a) said electrode array comprising a plurality of triangular-shaped wire electrodes each having two long wire sides connected at an apex, said electrodes being distributed side by side underneath the active tablet area such that the apices of adjacent triangular-shaped electrodes lie adjacent opposite sides of the active tablet area, a first terminal connected to the end of one long wire side opposite to its apex, a second terminal connected to the end of the other long wire side, (b) means connected to the wire terminals for; (i) determining, via its terminals, the electrical signal induced in each triangular-shaped electrode, (ii) locating the pointing device inductor position relative to all of the triangular-shaped electrodes by comparing the level of the signal induced in each electrode to that induced in neighboring electrodes. - View Dependent Claims (5, 6, 7, 8, 9, 10)
-
Specification