Capacitive touch switch array

A capacitor touch panel including an array of touch sensitive switch cells, said touch panel comprising:

• (a) a dielectric layer,
• (b) a first pattern of capacitor touch plates on one surface of said dielectric layer, each of said switch cells including first and second capacitor touch plates responsive to touch,
• (c) a second pattern of input and output capacitor plates on the opposing surface of said dielectric layer, each of said switch cells further including an input capacitor plate responsive to an input signal source, a first output capacitor plate providing a first output signal and a second output capacitor plate providing a second output signal,
• (d) a first pair of series capacitors for each switch cell being formed between said input capacitor plate, a first capacitor touch plate and a first output capacitor plate, respectively, and
• (e) a second pair of series capacitors for each switch cell being formed between said input capacitor plate, a second capacitor touch plate and a second output capacitor plate, respectively.

A panel including an array of cells arranged in first and second groups that define a system of coordinates for specifying the location of each cell within said array, which cells are individually accessible to external circuitry without a requirement for crossover conductors on said panel, comprising:

• (a) a dielectric layer,
• (b) a first pattern of first and second electrodes on one surface of said dielectric layer,
• (c) a second pattern of third electrodes on an opposing surface of said dielectric layer, each of said cells including a first, second and third electrode, said first and third electrodes being capacitively coupled together through said dielectric layer,
• (d) means for coupling said second electrodes together within each group of said second groups of cells and for providing first access means to said external circuitry, and
• (e) means for coupling said third electrodes together within each group of said first groups of cells and for providing second access means to said external circuitry.

A capacitive touch switch array, comprising:

• (a) an array of touch sensitive switch cells each including at least a pair of series capacitors,
• (b) a signal source coupled to said pair of series capacitors,
• (c) a signal detection circuit means having parasitic capacitance present between the input of said signal detection circuit means and ground, said parasitic capacitance having a fixed and a variable component,
• (d) a discrete capacitor coupled between the input of said signal detection circuit means and ground in parallel with said parasitic capacitance, said discrete capacitor having a value of capacitance large enough to substantially mask the variable component of said parasitic capacitance,
• (e) coupling means including said pair of series capacitors and said discrete capacitor for coupling the signal from said signal source to said signal detection circuit means as a voltage divided signal of a first voltage level, and
• (f) touch means associated with each switch cell for providing capacitive coupling of the junction of each pair of series capacitors of a selected switch cell to ground for actuating said selected switch cell and further voltage dividing the signal coupled to said signal detection circuit means to a second voltage level, said discrete capacitor serving to stabilize said first and second voltage levels.

A capacitive touch switch array, comprising:

• (a) an array of touch sensitive switch cells each including a first pair of series capacitors and a second pair of series capacitors,
• (b) a signal source coupled to said first and second pair of series capacitors,
• (c) first signal detection circuit means having parasitic capacitance between the input of said first signal detection circuit means and ground, said parasitic capacitance having a fixed and a variable component,
• (d) a first discrete capacitor coupled between the input of said first signal detection circuit means and ground in parallel with said parasitic capacitance, said first discrete capacitor having a value of capacitance large enough to substantially mask the variable component of said parasitic capacitance,
• (e) first coupling means including said first pair of series capacitors and said first discrete capacitor for coupling the signal source to the input of said first signal detection circuit means as a voltage divided signal of a first voltage level,
• (f) second signal detection circuit means having said parasitic capacitance between the input of said second signal detection circuit means and ground,
• (g) a second discrete capacitor coupled between the input of said second signal detection circuit means and ground in parallel with said parasitic capacitance, said second discrete capacitor having a value of capacitance large enough to substantially mask the variable component of said parasitic capacitance,
• (h) second coupling means including said second pair of series capacitors and said second discrete capacitor for coupling the signal from said signal source to the input of said second signal detection circuit means as a voltage divided signal of said first voltage level, and
• (i) touch means associated with each switch cell for providing capacitive coupling of the junctions of each pair of series capacitors of selected switch cell to ground for actuating said selected switch cell and further voltage dividing the signal coupled to said first and second signal detection means to a second voltage level, said first and second discrete capacitors serving to stabilize said first and second voltage levels.