Stylus-tracking piezoelectric sensor

A method of determining information regarding one or more interactions between a target object and a display device, the method comprising:

• acquiring first image data from at least a first portion of a piezoelectric receiver array, the first image data corresponding to signals produced by at least the first portion of the piezoelectric receiver array in response to at least one of an acoustic signal or a mechanical deformation caused by a target object in contact with a surface proximate a second side of the display during a first acquisition time window;
• detecting a first doublet pattern in the first image data, the first doublet pattern comprising a first area of the piezoelectric receiver array from which signals below a threshold signal level have been received and a second area of the piezoelectric receiver array from which signals above the threshold signal level have been received, the first area being adjacent to the second area;
• determining one or more first doublet pattern characteristics;
• determining, based on at least one first doublet pattern characteristic, at least one of a first position of the target object on the surface, a first force of the target object on the surface or a first direction of movement of the target object relative to the surface;
• determining a first centroid of the first area;
• determining a second centroid of the second area;
• determining a displacement between the first centroid and the second centroid;
• and
• estimating a velocity of the target object based, at least in part, on the displacement.

One or more non-transitory media having software stored thereon, the software including instructions for controlling one or more devices to perform a method of determining information regarding one or more interactions between a target object and a display device, the method comprising:

• acquiring first image data from at least a first portion of a piezoelectric receiver array, the first image data corresponding to signals produced by at least the first portion of the piezoelectric receiver array in response to at least one of an acoustic signal or a mechanical deformation caused by a target object in contact with a surface proximate a second side of the display during a first acquisition time window;
• detecting a first doublet pattern in the first image data, the first doublet pattern comprising a first area of the piezoelectric receiver array from which signals below a threshold signal level have been received and a second area of the piezoelectric receiver array from which signals above the threshold signal level have been received, the first area being adjacent to the second area;
• determining one or more first doublet pattern characteristics;
• determining, based on at least one first doublet pattern characteristic, at least one of a first position of the target object on the surface, a first force of the target object on the surface or a first direction of movement of the target object relative to the surface;
• determining a first centroid of the first area;
• determining a second centroid of the second area;
• determining a displacement between the first centroid and the second centroid;
• and
• estimating a velocity of the target object based, at least in part, on the displacement.