Depth sensor device and method for operating a depth sensor device

A sensor device for generating a depth map of a scene, the sensor device comprising

• a projector unit that is configured to project a plurality of temporal series of light patches on the scene, with consecutive light patches of one series being either shifted along a first direction or a second direction that is opposite to the first direction;
• a receiver unit that is arranged at a predetermined distance from the projector unit and configured to observe reflections of the light patches from the scene;
• and
• a control unit that is configured to temporally correlate the projected light patches with the observed reflections and to use the correlation and the predetermined distance to generate the depth map of the scene;
• wherein
• the projector unit is configured to alternatively project first sweeps and second sweeps, where each first sweep is a series of consecutive light patches that are shifted along the first direction and each second sweep is a series of consecutive light patches that are shifted along the second direction;
• the receiver unit comprises a plurality of event detection pixels that indicate occurrence of an event when a light intensity that is measured by a respective event detection pixel changes by more than a predetermined amount in a given time period;
• the time it takes for an event detection pixel to indicate the occurrence of an event depends on the absolute magnitude of the light intensity before the change of light intensity;
• each event detection pixel is configured to receive light only from a predetermined solid angle, wherein solid angles observed by adjacent event detection pixels are adjacent and the observed solid angles of all event detection pixels span the field of view of the receiver unit;
• the control unit is configured to determine during the first sweeps as well as during the second sweeps for each occurrence of an event the predetermined solid angle of the respective event detection pixel and the projection angle under which the projector unit did project a light patch at the time at which the event occurred;
• and
• the control unit is configured to average for each consecutive first sweep and second sweep and for each consecutive second sweep and first sweep for each respective pair of event occurrences the respectively determined projection angles, and to determine a depth map of the scene based on the pairs of predetermined solid angle and averaged projection angle determined for each event occurrence.