Patent ID: 8446572
Filing Date: 2013-05-21
Classification: G01J

Abstract:
1. A method of operating a sensing system which comprises a sensor for viewing an external scene, the sensor comprising at least one detector and circuitry associated with each detector comprising a detector diode, a capacitor disposed in parallel with the detector diode, a first switch, a second switch, and a bias supply interconnected by way of a junction to the first and second switches so that the first switch is positioned between the detector diode and the junction and the second switch is positioned between the junction and an output of the circuitry, the sensor having a field of view which overlaps with the path of a pulsed laser, the method comprising: switching the detector in accordance with operation of the pulsed laser to at least substantially reduce back-scattered radiation on overlapping portions of the laser path and the sensor field of view using the circuitry to switch the detector between a ‘stare’ period, when the first switch is closed and current discharges to the capacitor, and a ‘readout’ period, when the second switch is closed and voltage on the capacitor is measured, so that the ‘stare’ period does not overlap an ‘on’ time of the pulsed laser.