Reducing Noise in a Force Signal in an Electronic Device

摘要

A force sensing device can be included in a display. Noise produced by various sources can be injected into the force signals produced by the force sensing device. Example noise sources include, but are not limited to, the display, Johnson or Thermal noise from the force sensing device, system noise, and magnetically-coupled or background noise produced by ambient light sources. A sampling scheme that includes one or more noise cancelling techniques can be employed to reduce the amount of noise in the force signals.

主权项

1. A method of operating a force sensing device incorporated with a display of an electronic device, the method comprising:
dividing a scanning period for a frame of the display into a plurality of subscan time periods; and within each subscan time period, sampling force signals only during a scan period and not sampling force signals during a delay period, wherein the scan and delay periods are offset from one another within a subscan time period.