National Research Council of Canada

Istituto Trentino Di Cultura

J Angelo Beraldin

Francois Blais

Marc Rioux

Massimo Gottardi

Jacques Domey

Andrea Simoni

Lorenzo Gonzo

A position and color detection sensor (for detecting a position of a light spot in a light distribution that can include stray light components, e.g. from other lasers, ambient lighting etc.) includes two discrete response position sensitive detectors (DRPSDs). The first DRPSD is used to calculate a raw estimate of the spot position and the second DRPSD is used to calculate the actual spot position based on information from the first DRPSD. Color is supported by further dividing each pixel of the first DRPSD into elementary photocells, each one covered with an appropriate optical filter. The use of two DRPSDs differing in pixel geometries makes them suitable for integration on the same chip using the same process. This reduces production and alignment costs. Further, analogue microelectronic processes can be used for color filter deposition and simple optics can be used for beam splitting and shaping.

System and method of light spot position and color detection

The present invention provides a method and an apparatus for detecting a position of a light spot in a light distribution that can include stray light components (e.g. from other lasers, ambient lighting etc.) The apparatus includes a continous response position sensitive detector (CRPSD, e.g. lateral effect photo-iode) for determining a first centroid of the light distribution and a discrete response position sensitive detector (DRPSD, e.g. multiplexed array) for determining a second centroid of the light distribution within a reading window defined about the first centroid and within the light distribution. The second centroid represents the position of the light spot in the light distribution. This multiple stage approach exploits the high resolution and speed offered by traditional CRPSDs together with the accuracy under variable lighting conditions offered by traditional DRPSDs.

Position sensitive light spot detector

In active range finder apparatus wherein an object to be inspected is illuminated by a laser source and light reflected by the object is detected in an imaging photosensor, a system is provided for increasing the dynamic range of the apparatus. This system provides for integrating over each of a series of measuring time periods light reflected from a window of the photosensor and hence proportional to the light received by such photosensor. When such integrated light exceeds a predetermined amount, a saturation signal is generated that immediately de-energizes the source. If this amount is not reached by the end of each period, the system is reset. The source is gradually re-energized at the commencement of each subsequent period. The virtually instantaneous de-energization and gradual re-energization combined with use of a saturation detector separate from the main photosensor ensures rapid action that is quick enough to substantially avoid saturation of such main photosensor.

Method and system for increasing the effective dynamic range of a

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J Angelo Beraldin