Menu for a charge ratio digitizer

A digitizer tablet having a generally planar top surface, an electrode arrangement lying in a plane substantially parallel to said top surface, and a layer of insulating material between said top surface and said electrode arrangement, said electrode arrangement comprising first, second and third patterned electrodes arranged in a first area, first, second and third menu electrodes arranged in a second area, and first, second and third junction electrodes arranged in a third area, said first, second and third areas not overlapping, said first patterned electrode, said first menu electrode and said first junction electrode being electrically connected to form a first circuit, said second patterned electrode, said second menu electrode and said second junction electrode being electrically connected to form a second circuit and said third patterned electrode, said third menu electrode and third junction electrode being electrically connected to form a third circuit, said first patterned electrode having a first geometric pattern, said first pattern varying with a first coordinate in a two-coordinate system, said second patterned electrode having a second geometric pattern, said second pattern varying with a second coordinate in said two-coordinate system, said third patterned electrode having a third geometric pattern, being arranged between said first and second electrodes, and being separated from said first and second patterned electrodes by spacing means comprising insulating material, and said first, second and third menu electrodes each having a fourth geometric pattern.

A digitizing arrangement comprising:

• (a) first electrode means fixedly arranged in a first area of a plane for producing electrostatic forces which vary in first and second coordinate directions in response to receipt of driving signals;
• (b) second electrode means fixedly arranged in a second area of said plane for producing electrostatic forces in response to receipt of said driving signals;
• (c) signal generating means electrically connected to said first and second electrode means for outputting said driving signals thereto;
• (d) coupling means movable relative to said first and second electrode means and capable of producing induced output signals in response to receipt of said driving signal by said first and second electrode means when said coupling means is capactively coupled thereto;
• and
• (e) processing means electrically connected to receive said induced output signals from said coupling means, said processing means comprising first means for processing said induced output signals in accordance with a first routine in response to said coupling means having at least a predetermined threshold level of capacitive coupling with said first electrode means and second means for processing said induced output signals in accordance with a second routine in response to said coupling means having less than said predetermined threshold level of capacitive coupling with said first electrode means.