| 摘要 |
An apparatus comprises correlated emitter-detector pairs for determining the amount of electromagnetic (EM) radiation, such as optical light or infrared, received at a detector from its paired emitter. An array of emitters 23, 24 emits EM radiation and an array of detectors 25, 26, 27 detects said radiation. Drive control circuitry 37, 38, 39 controls the array of emitters 23, 24 so that they emit pulses of EM radiation at substantially the same clock frequency, the amplitude of the pulses being modulated using a set of mutually orthogonal binary vectors, each of which is different for each emitter. Detection circuitry processes a signal corresponding to the radiation reaching each particular detector in the array using the mutually orthogonal binary vector associated with the correlated emitter to produce a detection signal for that particular detector. This apparatus could be used in a touch screen device which allows the detection of actual touches (using frustrated total internal reflection and or the detection of near field objects by analysing the amount of radiation not received at a particular emitter. |
