Pressure sensitive projected capacitive touch sensing

摘要

A projected capacitive touch panel that can detect touch pressure. The cover layer of projected capacitive touch panel has protrusions with gaps that fill up partially when finger is pressed, thereby registering a large change in projected capacitance. A keyboard using such device with optional mechanical switches underneath the touch surface for tactile feedback. Haptic feedback is coupled to detection of touch pressure. Reconfigurable keyboard and trackpad regions on a touch panel sensitive to touch pressure with tactile feedback from underlying mechanical switches. A mouse with left and right click support using projected capacitive touchpad with pressure detection for mouse click. Human finger based mimicking of mouse operation in combination with touch pressure detection. Supporting gestures that use touch pressure. Providing a visual feedback in an underlying display when touch pressure is detected. Providing an audio feedback when touch pressure is detected.

主权项

1. A projected capacitive touch panel for detecting both touch as well as pressing of a finger on a touch panel comprising:
a plurality of drive electrodes that are conductive; a plurality of sense electrodes that are conductive; a layer of nonconductive material separating said drive electrodes from said sense electrodes; a cover layer with an underside and a topside, comprising of a nonconductive material, positioned above said sense electrodes and above said drive electrodes, wherein said cover layer has ridges that protrude out from said topside; wherein a capacitance is formed between each of said drive electrode and each of said sense electrode; wherein said capacitance between any said drive electrode and any said sense electrode reduces under influence of touch on said topside of said cover layer by a finger covering both said electrodes at their intersection in said panel, and then further increases with pressing of said finger on said cover layer by exertion of force by said finger on said panel; wherein said further increase in said capacitance is produced by the pressing of said finger into the region between said ridges.