Pixart Imaging Incorporated

Tong-Sen Liew

Keen-Hun Leong

Ching-Geak Chan

There is provided an optical positioning system including a detected surface, an optical sensor, a register and a processor. The detected surface has interleaved bright regions and dark regions arranged in a transverse direction. The optical sensor captures an image frame of the detected surface within a field of view thereof and using a shutter time, wherein the detected surface and the optical sensor have a relative movement in the transverse direction. The register records a type of a last passed edge. The processor calculates a first position using a first algorithm upon the recorded last passed edge being a bright-to-dark edge and the field of view being aligned with one of the dark regions, and calculates a second position using a second algorithm, different from the first algorithm, upon the recorded last passed edge being a dark-to-bright edge and the field of view being aligned with the same one of the dark regions.

Optical positioning system determining positions based on last passed edge

There is provided an operating method of an optical positioning system including: capturing an image frame of a detected surface, which has interleaved bright regions and dark regions, using a field of view and a shutter time of an optical sensor; counting a number of edge pairs between the bright regions and the dark regions that the field of view passes; calculating an average value of the image frame; calculating a ratio between the calculated average value and the shutter time; determining that the field of view is aligned with one of the dark regions when the ratio is smaller than a ratio threshold; and determining that the field of view is aligned with one of the bright regions when the ratio is larger than the ratio threshold.

Optical positioning system having high resolution

There is provided an operating method of an optical positioning system including: capturing an image frame of a detected surface, which has interleaved bright regions and dark regions, using a field of view and a shutter time of an optical sensor counting a number of edge pairs between the bright regions and the dark regions that the field of view passes; calculating an average value of the image frame; calculating a ratio between the calculated average value and the shutter time; determining that the field of view is aligned with one of the dark regions when the ratio is smaller than a ratio threshold; and determining that the field of view is aligned with one of the bright regions when the ratio is larger than the ratio threshold.

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Penang, Malaysia

Tong-Sen Liew