Systems and methods for touch sensing based on resistor-capacitor delays

A method for detecting touch at a given location on a substrate, the method comprising:

• providing a touch-sensing circuit formed on the substrate, the touch-sensing circuit comprising a first subcircuit and a plurality of touch-sensing nodes, the plurality of touch-sensing nodes including a first node and one or more additional nodes, wherein:
• i) the first node is electrically connected to the first subcircuit by a first conductor, ii) the first node is electrically connected to at least one of the one or more additional nodes by a second conductor, and iii) the one or more additional touch-sensing nodes are electrically interconnected by respective third conductors;
• detecting a voltage drop on the first subcircuit responsive to one of the plurality of touch-sensing nodes being touched or contacted by a capacitive body;
• and
• determining which of the plurality of touch-sensing nodes was touched or contacted based on a time delay between detecting the voltage drop and a voltage on the first subcircuit returning to a threshold, wherein each of the plurality of touch-sensing nodes is associated with a unique time delay responsive to being touched.

A method of fabricating a resistor network for a capacitive touch or contact sensing apparatus, the method comprising:

• forming a resistor network comprising a first subcircuit and a plurality of touch-sensing nodes, the plurality of touch-sensing nodes including a first node and one or more additional nodes, wherein:
• i) the first node is electrically connected to the first subcircuit by a first conductor, ii) the first node is electrically connected to at least one of the one or more additional nodes by a second conductor, and iii) the one or more additional touch-sensing nodes are electrically interconnected by respective third conductors;
• and
• connecting a controller to the resistor network, the controller being configured to:
• (i) detect a voltage drop on the first subcircuit responsive to one of the plurality of touch-sensing nodes being touched or contacted and (ii) determine which of the plurality of touch-sensing nodes was touched or contacted based on a time delay between detecting the voltage drop and a voltage on the first subcircuit returning to a first threshold, wherein each of the plurality of touch-sensing nodes is associated with a unique time delay responsive to being touched.