Abstract: There is described a method for waking up an optical sensing device from a sleep mode to a motion detection mode, the optical motion sensing device comprising a light source, a photodetector device, a motion sensing unit and a control unit, the motion detection mode being defined as a mode during which motion is detected between the optical motion sensing device and a portion of a surface illuminated by the light source at a defined flash rate being set between minimum and maximum flash rate values, the motion sensing unit sending motion reports to the control unit, the sleep mode being defined as a mode during which the flash rate is set to a low flash rate value being lower than the minimum flash rate value and no motion report being reported from the sensing unit to the control unit, wherein the method comprises during the sleep mode the steps of (i) illuminating said surface portion with radiation by means of the light source at the low flash rate value; (ii) detecting a radiation pattern reflected from t

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.

Abstract: There is described a method for measuring relative motion between an illuminated portion of a surface and an optical sensing device comprising a photodetector array, which includes a plurality of rows and columns of pixels respectively aligned along first and second axes, the method allowing to determine a measurement of the relative motion between the optical sensing device and the illuminated portion of the surface based on a comparison of motion features extracted from light intensity patterns obtained with the photodetector array, wherein said method includes a checking process between two light intensity patterns for discarding erroneous motion features due to the surface design.

Abstract: There is described a method for measuring relative motion between an illuminated portion of a surface and an optical sensing device comprising a photodetector array including a plurality of rows and columns of pixels respectively aligned along first and second axes comprising essentially the steps of comparing at a first point in time light intensity between neighbouring pixels of the photodetector array and determining along each of the first and second axes, edge direction data from the detected first light intensity pattern, extracting edge inflection data from the edge direction data from the detected first light intensity pattern, comparing at a second point in time light intensity between neighbouring pixels and determining along each of said first and second axes, the edge direction data from the detected second light intensity pattern, extracting edge inflection data from the edge direction data from the detected second light intensity pattern.

Abstract: There is described a method for measuring relative motion between an illuminated portion of a surface and an optical sensing device comprising a photodetector array including a plurality of rows and columns of pixels respectively aligned along first and second axes comprising essentially the steps of comparing at a first point in time light intensity between neighbouring pixels of the photodetector array and determining along each of the first and second axes, edge direction data from the detected first light intensity pattern, extracting edge inflection data from the edge direction data from the detected first light intensity pattern, comparing at a second point in time light intensity between neighbouring pixels and determining along each of said first and second axes, the edge direction data from the detected second light intensity pattern, extracting edge inflection data from the edge direction data from the detected second light intensity pattern.

Abstract: There is described a method for detecting a lift condition from an illuminated surface portion of an optical motion sensing device. According to a first embodiment, two different “loss-of-focus” thresholds are used. A first threshold is used when the optical pointing device is not moving, and a second threshold greater than the first one is used when the optical pointing device is moving. The optical device further requires means for detecting whether it is moving or not. According to a second embodiment, a dynamical loss-of-focus threshold depending on an average number of motion features that the surface exhibits to the sensor of the optical pointing device is used.

Abstract: There is described an optical sensing device, a method for controlling operation of an optical sensing device comprising a light source for illuminating a surface portion with radiation, a photodetector device having at least one photosensitive element responsive to radiation reflected from the illuminated surface portion, and conversion means for integrating an output signal of said at least one photosensitive element over time during an integration period of variable duration, which duration depends on power of the light source and level of radiation reflected from the illuminated surface portion. The optical sensing device further comprises a regulating system for controlling power if the light source as a function of a comparison between a parameter representative of the evolution of the integration of the output signal of the said at least one photosensitive element and at least one reference value.

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.

Abstract: There is described an optical sensing device, a method for controlling operation of an optical sensing device comprising a light source for illuminating a surface portion with radiation, a photodetector device having at least one photosensitive element responsive to radiation reflected from the illuminated surface portion, and conversion means for integrating an output signal of said at least one photosensitive element over time during an integration period of variable duration, which duration depends on power of the light source and level of radiation reflected from the illuminated surface portion. The optical sensing device further comprises a regulating system for controlling power if the light source as a function of a comparison between a parameter representative of the evolution of the integration of the output signal of the said at least one photosensitive element and at least one reference value.

Abstract: There is described a method of operating an optical motion sensing device comprising a light source and a photodetector device, the method comprising the steps of a) illuminating a surface portion with radiation by means of the light source, b) detecting radiation reflected from the illuminated surface portion by means of the photodetector device, c) detecting and measuring displacement with respect to the illuminated surface portion; and d) outputting motion reports that are each representative of a magnitude of the detected displacement, steps a) to d) defining a flash period and being repeated at a selected flash rate. The method further comprises the steps of e) comparing the magnitude of the detected displacement with a determined displacement threshold, and f) increasing or decreasing the flash rate if the magnitude of the detected displacement is respectively greater or lower than the displacement threshold. There is also described an optical motion sensing device implementing this method.

Abstract: There is described a method of post-processing and reporting detected displacement in an optical pointing device as well as a sensing device for an optical pointing device implementing this method. Displacement is detected and a first count representative of a magnitude of the detected displacement is accumulated in an associated accumulation unit, this first count representing the magnitude of the detected displacement at a first resolution (or detection resolution). The first count accumulated in the accumulation unit is processed to convert this first count into a report count representing the magnitude of the detected displacement at a second resolution (or reporting resolution) lower than the first resolution. This report count is then reported, for instance to a PC or an external controller. These operations are repeated to generate periodic motion reports at the second resolution.

Abstract: There is described a method for controlling the sensitivity profile of a photodetector (1; 1a to 1d) comprising at least one well (10; 10a to 10d) of a first conductivity type (e.g. N) formed in a semiconductor substrate (20) of a second conductivity type (e.g. P), this method comprising the steps of determining a desired sensitivity profile for the photodetector, forming at least one diffusion region (15; 15a to 15d) of the first conductivity type in a determined region of the well and/or forming at least one diffusion region (25) of the second conductivity type in the semiconductor substrate adjacent to the well, and connecting said at least one diffusion region of the first or second conductivity type to a positive or negative potential of a reverse-bias voltage applied across said well and said semiconductor substrate.

Abstract: A parasitically compensated resistor (50) for integrated circuits includes a substrate (52). A polysilicon resistor (54) is formed in the substrate (52). The polysilicon resistor (54) has a first end connected to a first lead (56) and a second end connected to a second lead (58). A conductive layer (62) is capacitively connected to the polysilicon resistor (54).