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Lawrence Bieber

Michel Willemin

Kevin Scott Buescher

Gil Afriat

James Harold Lauffenburger

Sylvain Grosjean

André Grandjean

James Harlod Lauffenburger

A method for measuring relative motion between an illuminated surface and an optical sensing device comprising a coherent light source and a photodetector array is described. The method includes illuminating under a determined gradient, using the coherent light source, a surface portion at a determined flash rate; detecting, using the photodetector array, speckled light intensity pattern of the illuminated surface portion for a first flash; detecting a second speckled light intensity pattern of the illuminated surface portion for a second flash; extracting motion features of two different types from the detected first and second speckled light intensity patterns; determining a measurement of relative motion between the optical sensing device and the illuminated surface portion based on comparison of motion features extracted; wherein the method further comprises a filtering step in order to adjust, and preferably decrease, the number of motion features used in the step of determining a measurement of relative motion.

Motion detection mechanism for laser illuminated optical mouse sensor

A method for measuring relative motion between an illuminated portion of a surface and an optical sensing device comprising a coherent light source and a photodetector device comprising an array of pixels and comparators for extracting motion features. The method includes the steps (a)-(d). Step (a) includes illuminating with the coherent light source the surface portion at a determined flash rate. Step (b) includes detecting, using the array of pixels a speckled light intensity pattern of the illuminated portion of the surface for each flash. Step (c) includes extracting edge direction data of two different types from the detected speckled light intensity patterns. Step (d) includes measuring relative motion between the optical sensing device and the illuminated portion of the surface based on extracted edge direction data. The step of extracting edge direction data further includes a preliminary step of introducing a selecting factor, which promotes detection of one type of edge direction data rather than another type.

Optimization of statistical movement measurement for optical mouse, with particular application to laser-illuminated surfaces

The invention concerns an optical pointing device comprising a coherent light source for illuminating a surface portion with radiation, a driver of the coherent light source for controlling coherent light emissions, a photodetector device responsive to radiation reflected from the illuminated surface portion, processing means for determining, based on the photodetector device response, a measurement of relative motion between the optical pointing device and the illuminated portion of the surface, wherein the coherent light source driver is a fault-tolerant driver comprising redundant power control means for limiting the output power of coherent light emissions.

Single fault laser driver control for optical mouse

A method for detecting lift from a surface portion of an optical pointing device comprising a coherent light source, a photodetector device including an array of pixels, and extracting motion features including comparators with an adjustable offset value, the method comprising the steps of: (i) illuminating the surface portion with radiation by the coherent light source; (ii) detecting radiation patterns reflected from the illuminated surface portion with the photodetector device; (iii) comparing light intensity between neighbouring pixels in the detected radiation patterns; (iv) extracting motion features as a function of the result of the comparison; (v) counting the total number of motion features extracted; (vi) increasing or decreasing the comparator offset value when the total number of motion features increases or decreases; (vii) comparing the comparator offset value with an offset threshold; (viii) enabling detection of a lift condition if the comparator offset value is lower than the offset threshold.

Enhanced lift detection technique for a laser illuminated optical mouse sensor

There is described a method for measuring relative motion between an illuminated portion of a surface and an optical sensing device comprising a coherent light source and a photodetector array, the method comprising the steps of illuminating under a determined gradient by means of the coherent light source the surface portion at a determined flash rate; detecting by means of the photodetector array speckled light intensity pattern of the illuminated portion of the surface for a first flash; detecting a second speckled light intensity pattern of the illuminated portion of the surface for a second flash; extracting motion features of two different types from the detected first and second speckled light intensity patterns; determining a measurement of the relative motion between the optical sensing device and the illuminated surface portion based on a comparison of motion features extracted; wherein before the step of determining a measurement of the relative motion, the method further comprises the step of keeping only pairs of neighbouring motion features including one motion feature of both different types.

A method for operating an optical sensing device having a light source and a photodetector device with at least one photosensitive element. A surface portion is illuminated with radiation by the light source and the radiation reflected from the illuminated surface portion is detected with a photosensitive element. While said surface portion is being illuminated, an output signal of the photosensitive element over time is integrated, the output signal integration level is compared with a first integration reference level during integration; the integration step is interrupted if the output signal integration level has reached the first integration reference level, or the comparison step is repeated until a first integration period has elapsed if the output signal integration level has not reached the first integration reference level.

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Colorado Springs, CO, United States of America

Lawrence Bieber