Abstract: 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 keep

Abstract: The invention concerns an electronic circuit (10) for measuring a force, including a capacitive sensor (12) connected to a capacitive bridge (14), of the type wherein the capacitive sensor (12) includes a moving electrode (16) suspended elastically between a first (18) and a second (20) fixed electrode so as to form respectively a first (C1) and a second (C2) capacitor whose capacitance is variable, of the type wherein the capacitive bridge (14) generates an electric output signal (Vs), which is a function of the capacitance variations of the capacitors (C1, C2), of the type wherein the capacitance value of each capacitor (C1, C2) is substantially lower than one picofarad, when the moving electrode (16) occupies a rest position, and of the type wherein the excitation frequency of the circuit (10) is comprised overall within the low frequency range, characterised in that a series impedance element (26, 28, 30) is interposed between each of the three electrodes (16, 18, 20) and the capacitive bridge (14) so as

Abstract: The present invention concerns a device for detecting crossing of a horizontal land demarcation marker of a carriageway for motor vehicles, characterized in that it includes at least one box (2) to be placed under the vehicle and enclosing means for projecting two light beams (4, 6) onto the carriageway (8) in two distinct zones (10, 12) that do not overlap, and distinct means for picking up each of the two light beams (14, 16) after reflection onto the carriageway (8).

Abstract: There is described a method of providing indication of low battery status of a battery-powered pointing device designed for detecting motion and outputting motion reports representative of the detected motion, the method comprising the steps of detecting low battery status of the pointing device and affecting output of the motion reports, upon detection of the low battery status, by adding determined and/or pseudo-random components of motion to the motion reports.

Abstract: There is described a method for extending battery life in an optical pointing device powered by one or more battery cells (30), the optical pointing device including an optical motion sensing device (10) for tracking motion with respect to a surface (S) and comprising motion sensing circuitry (12) coupled to an optical sensor (15) and at least one light source (14) for illuminating a portion of the surface. The method comprises the steps of (i) monitoring the power output of the said one or more battery cells (30), (ii) detecting when the said power output falls below a certain threshold indicative of a low battery status (EOL) and (iii) upon detection of the low battery status, switching the optical pointing device into a low power consumption mode where power consumption of the optical pointing device is reduced and performance of the optical motion sensing device is partially degraded. There is also described an optical pointing device implementing this method.

Abstract: A magnetic sensing unit for measuring displacements on a nanometer scale is provided. A moveable part and a fixed part of a microdevice magnetic sensing unit comprises a magnetic element having a magnetic field and a magnetic sensor, the magnetic element being located on the moveable part and the magnetic sensor on the fixed part, or alternatively, the magnetic sensor being located on the moveable part and the magnetic element on the fixed part. The magnetic sensor and/or the magnetic element comprise an integral part of the microdevice. The magnetic element and the magnetic sensor are arranged relative to each other such that when the moveable part is displaced the change of the magnetic field at the magnetic sensor is detectable by use of the magnetic sensor.