| 摘要 |
<p>A digitizer in which position of a free moving cursor or stylus over a digitizing surface is determined by electrostatic coupling of the cursor with three coplanar electrodes imbedded in the digitizing tablet. The electrodes consist of a repetitive sawtooth pattern to determine position in one axis, the sawtooths interleaved with progressively wider, repetitive stripes to determine position in another axis. The third electrode covers the remainder of the coplanar surface area. Only three electrode signals are required to be electronically processed to determine absolute vertical and horizontal position of the cursor over the digitizing tablet by a ratiometric measurement. The signals from the electrodes are processed synchronously to reject noise.</p> |
