US 8,077,034 B2Granted

Sensor for presence detection

AssigneeBea SA

InventorsYves Borlez, Olivier Gillieaux, Christian Leprince

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Abstract

The invention refers to a sensor (10) for presence detection, and a method for presence detection, in a detection area (18) comprising at least an image generator (14) for generating an image on a detection area (18) formed by illuminated structures reflecting from said detection area (18), a detector (20) for detecting signals of the image reflected from the detection area (18), an image processing unit (24) for comparing the signals based on the reflected and received image with signals of a reference image stored in storing means of the image processing unit (24), wherein the image generator (14) generates a pattern (16) on the detection area (18) having illuminated and non-illuminated zones, the image processing unit (24) uses triangulation technique to detect changes of the pattern (16) within the detection area (18) over the reference image.

Claims20

Dependent claims

A sensor (10), comprising:

said sensor detecting presence in a detection area (18);
a pattern generator (14);
said pattern generator (14) projecting a pattern (16) on the detection area (18);
said pattern generator (14) generates said pattern (16) on said detection area (18) having illuminated and non-illuminated zones;
said pattern generator (14) generates pulsed patterns (16);
storing means for storing signals of a reference image pattern;
an image processing unit (24);
a camera (20) separated from the pattern generator (14) by a predetermined distance (D);
said camera detecting signals of said pattern (16) reflected from said detection area (18);
said camera (20) having a global shutter and a control unit;
said control unit controls said shutter and said pattern generator (14) to synchronize the opening of said shutter with the pulse frequency of said pattern generator (14) to open said shutter with the beginning of said pattern pulse and to close said shutter at the end of said pattern pulse;
an object residing partially or wholly within said pattern;
said image processing unit (24) triangulating an object in said pattern (16) within said detection area (18);
and, said image processing unit (24) comparing said reflected and received pattern (16) with said object present in said detection area with said signals of said reference image pattern stored in said storing means of said image processing unit (24).

11 more elements

Method for presence detection in a detection area (18), comprising the steps of:

generating, using at least one pattern generator (14), a pattern (16), on the detection area (18) having illuminated and non-illuminated zones;
generating pulsed patterns (16) using said pattern generator (14);
detecting, synchronously, said patterns (16) using a camera (20) on said detection area (18) as the global shutter of the camera (20) is opened when the pulsed pattern (16) is projected on said detection area (18);
detecting said pattern (16) on said detection area (18) using the camera (20), and generating output signals;
and,
comparing and triangulating, using an image processing unit (24), said output signals based on reflected and received pattern (16), with signals of a reference pattern stored in storing means of said image processing unit (24), to detect changes of said pattern (16) within said detection area (18) with respect to said reference pattern.

3 more elements

Dependencies are inferred from the claim text.