Co-axial depth map sensor with an extended depth range

Abstract

The conventional depth map sensors have limited depth range, or they need to sacrifice depth accuracy for a larger working range. To overcome such problems, in this work, we propose a co-axial depth map sensor with an extended depth range based on controlled aberrations. This depth map sensor implements depth measurement by projecting a near-infrared astigmatic pattern onto the test scene and measuring the contrast change of the reflected pattern image in the tangential and sagittal directions. By adding a tunable lens in the projection optics, this depth map sensor can achieve the extended depth measurement without the loss of high depth accuracy and high depth map resolution.