Patent ID: 9052771
Filing Date: 2015-06-09
Classification: G06F

Abstract:
1. A method of calibrating optical components in a light-based touch screen, comprising: providing (i) a display, (ii) a row of light pulse emitters, denoted E, that sequentially transmit light pulses over the display according to their calibrated pulse current or pulse duration controls, and (iii) a row of light pulse receivers, denoted R, that receive the sequence of light pulses transmitted by the emitters and that sequentially generate output values quantifying their received light pulses, each emitter-receiver pair (E, R) having an expected output for receiver R of the pair when the light pulses transmitted by emitter E of the pair are not blocked by an object touching the display; determining if the actual output value for receiver R′ of a specific non-blocked pair (E′, R′) is outside a designated range from the expected output for (E′, R′); conditional upon said determining being affirmative, further determining if the actual output values of receivers R″ of non-blocked pairs (E″, R″) other than (E′, R′) vary among themselves by less than an expected noise level for a number, N, of output values over time, where N is at least two; and conditional upon said further determining being affirmative, recalibrating emitter E′, comprising adjusting at least one of the pulse current and pulse duration for emitter E′ such that subsequent actual output values for receiver R′ are within the designated range.