Digitizer cursor coil for reducing edge effect

Abstract

A digitizer cursor coil for use as part of a digitizer is disclosed. The cursor coil includes a primary winding and a secondary winding concentric with the primary winding and having a larger diameter than same. The windings are connected together in series such than when they are energized, current flow in the primary coil is in a direction opposite to the direction of the current flow in the secondary coil. The digitizer cursor includes a lens assembly comprising a bottom core and a top core both of which are formed from a disk shaped transparent material. The primary winding is wrapped into a groove formed in the bottom core, the secondary winding is wrapped into a groove formed in the top core. Cross hairs and a cross hair center point are formed in the bottom core. The top core is movable relative to the top core so that when the cursor coil is energized the center point of the magnetic field formed thereby can be aligned with the cross hair center point.

Dependencies are inferred from the claim text.