Abstract: Method and sensor assembly determining the condition of a structure, especially for confirming if a measured fingerprint is on a live finger, by measuring characteristics of close to the structure surface, the sensor comprising a first pair of current supply electrodes coupled to a current source, providing an electrical current to the skin, at least two pickup electrodes at chosen and different positions relative to the current supply electrodes, at least a first of said pickup electrodes being coupled to an instrument for measuring the voltage between said first pickup electrode and at least one of the pickup or current supply electrodes, storage means for a predetermined set of values characterizing a certain condition of the surface, and means for comparing the characteristics from each pickup electrode with the measurements of the other pickup electrodes and with the predetermined set of characteristics for determining the surface condition.

Abstract: A sensor device for performing measurements on an at least partially conductive surface includes a number of conductive structures at or directly below the sensor surface. The conductive structures consist of at least one stimulation or current sink electrode and a number of sensor elements coupled to interrogation electrodes in an electronic circuit for measuring impedance between the electrodes and the stimulation electrode. The sensor device also includes at least one additional clamping electrode positioned in the vicinity of the sensor elements and coupled to a chosen voltage.

Abstract: A sensor chip for measuring of structures in a finger surface includes an electronic chip provided with a number of sensor electrodes for capacitance measurements. The chip further includes a first layer comprising a metal or another electrically conducting material over and coupled to the sensor electrodes and a first dielectric layer substantially covering the first metal layer.

Abstract: This invention relates to a pointer tool for connecting to a display device, comprising a number of sensors elements being positioned on a two dimensional surface, for measuring a predetermined parameter at a surface, the measured quantity being sampled at a chosen rate, and calculating means for comparing the measurements from the sensor elements for detection of movements in two dimensions over the elements based on changes in the measured parameter, the time between the changes and the known relative positions between the sensor elements.

Abstract: Sensor chip, especially for measuring of structures in a finger surface, characterized in that it comprises an electronic ship being in a per se known way provided with a number of sensor electrodes for capacitance measurements, the chip being provided with a first layer comprising a metal or another electrically conducting material over and coupled to the sensor electrodes and a first dielectric layer substantially covering the first metal layer.

Abstract: The invention relates to a sensor chip, especially for measuring structures in a finger surface, comprising an electronic chip of a per se known type being provided with a number of sensor electrodes for capacitance measurements, the chip being positioned on a substrate being provided with a number of openings or slots through which electrical conductors are provided, the ends of said conductors constituting a sensor array for capacitance measurements so that the sensor array is positioned on a first side of said substrate and the electronic chip is positioned on the other side of the substrate.

Abstract: This invention relates to a pointer tool for connecting to a display device, comprising a number of sensors elements being positioned on a two-dimensional surface, for measuring a predetermined parameter at a surface, the measured quantity being sampled at a chosen rate, and calculating means for comparing the measurements from the sensor elements for detection of movements in two dimension over the elements based on changes in the measured parameter, the time between the changes and the known relative positions between the sensor elements.

Abstract: Sensor chip, especially for measuring of structures in a finger surface, characterized in that it comprises an electronic ship being in a per se known way provided with a number of sensor electrodes for capacitance measurements, the chip being provided with a first layer comprising a metal or another electrically conducting material over and coupled to the sensor electrodes and a first dielectric layer substantially covering the first metal layer.

Abstract: Sensor chip, especially for measuring structures in a finger surface, characterized in that it comprises an electronic chip of a per se known type being provided with a number of sensor electrodes for capacitance measurements, the chip being positioned on an electrically insulating substrate being provided with a number of openings through which electrical conductors are provided, the ends of said conductors constituting a sensor array for capacitance measurements so that the sensor array is positioned on a first side of said substrate and the electronic chip is positioned on the other side of the substrate.

Abstract: This invention relates to a sensor module for measuring structures in a surface, especially in a finger surface being moved over the sensor module, that includes a number of sensor elements, and an outer electrode located aside the sensor elements, the sensor elements being coupled to at least one AC drive circuit providing a varying current or voltage, thus coupling a signal through the sensor elements to the outer electrode. The sensor elements are also coupled to an electronic circuit positioned on a substrate, the substrate includes conductor leads coupling the sensor elements to the electronic circuit, and the electronic circuit being adapted to measure the magnitude of the capacitance or AC impedance.

Abstract: This invention relates to a system for measuring patterns in finger surfaces, the system comprising an array of sensor electrodes over which the surface is to be moved, and at least one stimulation electrode for providing a varying current or voltage between the stimulation electrode and the number of sensors through the surface. The stimulation electrode is positioned separately from the array of sensor electrodes and the system comprises a generator coupled to the stimulation electrode for applying a current or voltage with a varying amplitude or phase to the surface. The system comprises a measuring unit coupled to the sensor electrodes for, during the application of the current or voltage, measuring the impedance at the sensor electrodes in a time sequence and calculating values of predetermined characteristics of the surface and combining the calculated values for the sensor electrodes over the time sequence for generating a representation of the surface pattern.

Abstract: This invention relates to a sensor assembly and a method for measuring characteristics of a surface, preferably skin, comprising a first pair of current supply electrodes coupled to a current source, providing an electrical current to the skin, at least one pickup electrodes at chosen positions relative to the current supply electrodes, at least a first of said pickup electrodes being coupled to an instrument for measuring the voltage between said first pickup electrode and at least one of the pickup or current supply electrodes.

Abstract: This invention relates to a navigation tool for connecting to a display device, comprising at least two sensor elements having known positions relative to each other, each sensor element being coupled to detector means for recording a change in a predetermined parametre and timing means for determining the time of change at each sensor element and calculating means for calculating the direction and speed of the recorded changes based on the relative positions of the sensor elements and the duration between the recorded changes.

Abstract: Method and sensor assembly determining the condition of a structure, especially for confirming if a measured fingerprint is on a live finger, by measuring characteristics of close to the structure surface, the sensor comprising a first pair of current supply electrodes coupled to a current source, providing an electrical current to the skin, at least two pickup electrodes at chosen and different positions relative to the current supply electrodes, at least a first of said pickup electrodes being coupled to an instrument for measuring the voltage between said first pickup electrode and at least one of the pickup or current supply electrodes, storage means for a predetermined set of values characterizing a certain condition of the surface, and means for comparing the characteristics from each pickup electrode with the measurements of the other pickup electrodes and with the predetermined set of characteristics for determining the surface condition.

Abstract: This invention relates to a sensor module for measuring structures in a surface, especially in a finger surface being moved over the sensor module, comprising a number of sensor elements, and an outer electrode located aside the sensor elements, the sensor elements being coupled to at least one AC drive circuit providing a varying current or voltage, thus coupling a signal through the sensor elements to the outer electrode. The sensor elements are also coupled to an electronic circuit positioned on a substrate, said substrate comprising conductor leads coupling the sensor elements to the electronic circuit, and said electronic circuit being adapted to measure the magnitude of said capacitance or AC impedance.

Abstract: A number P of single analog inputs receive an analog signal having a frequency F from a sensor electrode. A single digital output sequentially generates a number P of first digital signals coding the amplitude values of the analog signal. A first multiplexer with a number M of multiple analog inputs with a number N of single analog inputs receives the analog signal and outputs the analog signal on a multiple analog output with a number N of second single analog outputs. A phase sensitive amplifier with a number N of single analog inputs and a number N of single analog outputs is connected to the second single analog outputs of the fist multiplexer. A second multiplexer with a number N of single analog inputs and a single analog output is connected to the single analog outputs of the phase sensitive amplifier.