Measurement system for optical touch trigger or scanning probe with a concave mirror

摘要

The present invention discloses a method for determining the position and/or the displacement of a mobile element with respect to a fixed frame, consisting in using a fixed light source (1) emitting a beam of light, arranging the light source (1) with respect to the mobile element and with respect to the a sensor (2) in a way so as to induce an interaction between the beam of light and the sensor which depends on the position of the mobile element and using processing and computing means for providing a value of the position and/or the displacement of the mobile element in dependence of the output signal of the sensor, characterized in that it consists in using a concave mirror (3), integral in movement with the mobile element, for reflecting the beam of light in direction to the sensor, arranging on the path of the beam of light a fixed optical mask (4) which presents a two dimensional regular pattern interlaced with an absolute code, detecting and processing the image casted by the optical mask on the sensor, computing the displacement value of the said image on the said sensor and using the computed displacement value for computing and providing the position and/or the displacement in at least one direction of the mobile element in dependence of the image's displacement.