Optical sensing device to sense displacement

摘要

An optical sensing device to measure displacement in a parallel direction perpendicular to a proximate surface is disclosed. The optical sensing device may comprise a tracking light source, a displacement light source, a displacement optical element, and a sensor. The tracking light source may generate a first beam spot on the proximate surface and the displacement light source may generate a second beam spot. The second beam spot may be smaller than the first beam spot. The displacement light source may be optically coupled with the displacement optical element to generate the second beam spot at an incident angle α that may generate a shift in the second beam spot position when the optical sensing device is displaced relative to the proximate surface. The shift in the second beam spot position to a new position may correspond to a displacement of the optical sensing device in a direction perpendicular to the proximate surface.

主权项

1. An optical sensing device for sensing a proximate surface, the optical sensing device comprising:
a tracking light source configured to generate a first beam spot on the proximate surface; a displacement light source configured to generate a second beam spot on the proximate surface, such that the second beam spot is relatively smaller than the first beam spot; a sensor configured to capture a first image of the proximate surface when the first beam spot is generated, and configured to capture a second image of the proximate surface when the second beam spot is generated; and a circuitry configured to convert the second image into a binary image, wherein the binary image comprises pixels that have one of two distinct pixel values assigned thereto; wherein the circuitry is configured to generate a displacement value corresponding to the displacement of the optical sensing device in a direction perpendicular to the proximate surface based on the binary image.