Microsoft Corporation
Method to reduce blanking area for palm rejection in low cost in-cell displays

Abstract:

Methods and systems are provided for receiving touch intensity signals from touch sensors of a touch screen. A spatial pattern in the touch intensity signals may indicate a deformation contour in the touch screen. A palm touch region is detected by comparing magnitudes of the touch intensity signals to a first touch-detection threshold. A second touch-detection threshold is assigned to a first perimeter region surrounding the palm touch region. The second touch-detection threshold may be a constant value or may vary over the first perimeter region of the touch screen. The second touch detection threshold may be determined by adjusting the first detection threshold. The second touch-detection threshold may be based on a slope of the touch intensity signals. The second touch-detection threshold provides a margin for reducing false touch signals near the palm touch region. The first touch-detection threshold is assigned to a region outside the first perimeter region.