US Patent 9471170 Light-based touch screen with shift-aligned emitter and receiver lenses

A touch screen including a housing, a display mounted in the housing, a plurality of collimating lenses mounted in the housing along two opposite edges of the display and arranged along the two edges so as to be shift-aligned relative to one another, a plurality of light pulse emitters mounted in the housing that are spaced apart from and transmit light pulses through the collimating lenses of one of the two edges over the display, a plurality of light pulse receivers mounted in the housing that are spaced apart from and receive the light pulses through the collimating lenses of the opposite of the two edges, and a calculating unit, mounted in the housing and connected to the receivers, that determines a location of a pointer on the display that partially blocks the light pulses transmitted by the emitters, based on outputs of the receivers.