Force detecting method for capacitive touch screen

摘要

A method for force detection of a deformable touch element with a capacitive touch-screen device includes providing drive and sense electrode arrays and a touch-detection circuit connected to the electrodes for detecting capacitance at a touch location. No-touch capacitance, light-touch capacitance, and heavy-touch capacitance are sensed with the touch-detection circuit at the touch location in response to forcible deformation of the deformable touch element proximate to the touch and a force signal reported.

主权项

1. A method for force detection of a deformable touch element with a capacitive touch-screen device, comprising:
providing a first array of drive electrodes and a second array of sense electrodes in association with a touch-detection area on a surface of a touch screen; providing a touch-detection circuit connected to the drive electrodes and connected to the sense electrodes for detecting capacitance at a touch location in the touch-detection area; sensing no-touch capacitance with the touch-detection circuit at the touch location in the absence of the deformable touch element proximate to the touch location and reporting a no-touch signal; sensing light-touch capacitance different from the no-touch capacitance with the touch-detection circuit at the touch location in the presence of a light-touch deformation of the same deformable touch element on the surface proximate to the touch location and reporting a light-touch signal at least partially responsive to a touch area of the light-touch deformation; sensing heavy-touch capacitance different from both the no-touch capacitance and the light-touch capacitance with the touch-detection circuit at the touch location in the presence of a heavy-touch deformation of the same deformable touch element on the surface proximate to the touch location and reporting a heavy-touch signal at least partially responsive to a touch area of the heavy-touch deformation greater than the touch area of the light-touch deformation; and determining a sequential progression of sensed capacitance values from no-touch to light-touch to heavy-touch indicating a sequential series of progressively more forceful touches or determining a sequential progression of sensed capacitance values from heavy-touch to light-touch to no-touch indicating a sequential series of progressively less forceful touches.