Microsoft Corporation
Switched polarization imaging to detect display screen

Abstract:

An imaging system comprises an optical sensor array with a plurality of sensor elements, an objective lens, an active polarization filter, and associated logic. The objective lens is configured to direct light from a field of view onto the plurality of sensor elements. Switchable electronically between first and second operational states, the active polarization filter is positioned to filter the light en route to the optical sensor array. The active polarization filter provides unequal relative attenuance, in the first versus the second operational state, of nonparallel polarization components of the light. The logic is configured to switch the active polarization filter from the first operational state to the second operational state, and to compare a light-intensity response of the plurality of sensor elements in the first operational state to the light-intensity response of the plurality of sensor elements in the second operational state.