Inventors:
Robert Rotzoll - Greeb Mountain Falls CO, US
Kevin Scott - Colorado Springs CO, US
James Harold - Colorado Springs CO, US
Gil Afriat - Monument CO, US
International Classification:
G09G005/08
Abstract:
There is described a method as well as a device for motion detect ion in an optical sensing device, such as an optical mouse. A photodetector array comprising a plurality of pixels is used to detect successive light intensity patterns of an illuminated portion of a surface with respect to which a measurement of relative motion is to be determined. Light intensity between neighbouring pixels is compared in order to determine edge direction data descriptive of light intensity differences between the pixels, such data including (i) a first edge condition, or positive edge, defined as a condition wherein light intensity of a first pixel is less than light intensity of a second pixel, and (ii) a second edge condition, or negative edge, defined as a condition wherein light intensity of the first pixel is greater than light intensity of the second pixel. Through comparison of this edge direction data with edge direction data determined from a previous illumination (or by comparing data extracted from this edge direction data) a measurement of the relative motion of the optical sensing device with respect to the illuminated portion of the surface is determined.