Patent ID: 9218069
Filing Date: 2015-12-22
Classification: G06F

Abstract:
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.