Abstract: A portable, light weight support stand for vertical mounting and use of a flexible digitizer. The stand is placed against a wall or other vertical structure so that writing pressure on the digitizer is supported by the wall and not by the stand. The entire structure is supported by legs extending at an angle from the stand to a floor adjacent to the supporting wall. The result is a very light weight, highly portable structure that provides all of the support necessary to maintain writing operations on a flexible digitizer while avoiding the weight and awkwardness of conventional rigid digitizers and support stands.

Abstract: An illumination apparatus for a digitizer tablet includes a support structure and a solid sheet optical light guide supported by the support structure and having first and second opposing surfaces and a plurality of edges. Light sources are carried by the support structure and positioned to direct light into light-receiving edges of the light guide. Reflecting structure is disposed adjacent the first surface of the light guide. A predetermined pattern is disposed on the first surface of the light guide structured and arranged in accordance with distance from the light sources.

Abstract: 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.

Abstract: An X-Y coordinate position locating or measuring digitizing device in which a cursor (inductor), moveable within an electromagnetic field generated by successively activated grid wires, develops a voltage from the field, and, in conjunction with conditioning circuits, yields the electrical intelligence required to indicate its position with a high degree of precision. Currents are successively passed through parallel grid lines for a given axis at discretely separate distances, the resultant successively generated field inducing a time variant voltage at the cursor coil output with amplitude and phase dependent upon the position of the cursor in relation to the actuated grid line. Conditioning circuitry to which the cursor coil output is coupled uniquely detects the phase reversal in the cursor coil output signal, interprets this reversal point in a manner which very accurately and linearly relates cursor position to time, and generates a "STOP" pulse indicating that the above phase reversal has been sensed.

Abstract: A position digitizing device in which a cursor, moveable within a field generated by successively activated grid wires, developes a voltage from the field and, in conjunction with conditioning circuits, yields the electrical intelligence required to indicate its position with a high degree of precision. Currents are successively passed through parallel grid lines at discretely separate distances, the resultant successively positioned fields successively inducing voltages at the cursor coil output dependent upon the position of the cursor in relation to the actuated grid line. Conditioning equipment to which the cursor output is coupled mixes the cursor output with a reference and introduces circuitry responsive to the rate at which the grid currents are successively stepped to translate the cursor output to a time variant wave form.