A cursor for use with an X-Y grid tablet comprises a single integral transparent plastic member having a substantially flat face with a circular groove machined or molded therein and crosshairs etched into the area enclosed by the groove. The member is mounted on a rotatable plate and magnet wire is wound inside the channel by using a needle having an eye large enough to allow the wire to pass therethrough. The base is rotated the exact number of times to establish the desired characteristic of the coil. A removable cap which fits over the area within the channel may be used to hold the wire while the base is turning. The ends of the wire pass through an aperture to the opposite side of the base. The completed coil is potted within the channel using an electrical grade epoxy.
A novel cursor construction for a digitizer tablet, wherein the cursor coil is wound on a one-sided bobbin which is then seated in a blind hole of a transparent base, with a crosshair molded into the base and aligned with the coil.
A mouse or track ball has a roller ball mounted within a housing by three free rollers in contact with an outer peripheral surface of the roller ball. An inner core of the roller ball is provided of a magnetic material having either bumps or holes at an outer periphery thereof. The inner core is coated with a non-magnetic material providing an outer smooth and round surface for the ball.
A grid consists of a first serpentine, and a second serpentine overlapping the first serpentine. Signals from the first and second serpentines are analyzed to determine transducer position. The first and second serpentines are foldback serpentines. The first serpentine is offset from the second serpentine by approximately ninety degrees.
