Patent ID: 7271919
Filing Date: 2007-09-18
Classification: G01B

Abstract:
1. A sensor for optical displacement measurement in accordance with a confocal imaging principle, comprising: a first optical output adapted to emit a first illumination beam; a second optical output adapted to emit a second illumination beam; a beam splitter positioned so that the first illumination beam after a transmission through the beam splitter and the second illumination beam after a reflection at the beam splitter are merged; an imaging optic, arranged and designed so that the two merged illumination beams are directed onto a surface of a measurement object, whereby, because of different displacements of the first and second optical outputs with respect to the beam splitter, a first real image of the first optical output and a second real image of the second optical output are created at different distances from the imaging optic; a first optical input coinciding in location with the first optical output, so that a first measuring beam, created by at least a partial reflection of the first illumination beam, is created on the surface, the first illumination beam arriving in the first optical input after passing through the imaging optic and after a transmission through the beam splitter; a second optical input coinciding in location with the second optical output, so that a second measuring beam, created by at least a partial reflection of the second illumination beam, is created on the surface, the second illumination beam arriving in the second optical input after passing through the imaging optic and after a reflection at the beam splitter; a first light detector adapted to record an intensity of the first measurement beam; a second light detector adapted to record an intensity of the second measurement beam; an evaluation unit, coupled to the first and second light detectors, adapted to determine, from a comparison of the intensity of the first measurement beam and the intensity of the second measurement beam, a distance between the sensor and the surface; at least one further first optical output, positioned adjacent to the first optical output, each adapted to emit a further first illumination beam which, after a transmission through the beam splitter and after passing through the imaging optic, arrives at the surface; at least one further second optical output, equal in number to the at least one further first optical output and positioned adjacent to the second optical output, each adapted to emit a further second illumination beam which, after a reflection at the beam splitter and after passing through the imaging optic, arrives at the surface; at least one further first optical input, equal in number to the at least one further first optical output, each of the at least one further first optical input corresponds to one of the at least one further first optical output and coincides in location with the corresponding one of the at least one further first optical output, so that in each case a further first measuring beam is created on the surface by at least partial reflection of a further first illumination beam arriving in the further first optical input after passing through the imaging optic and after a transmission through the beam splitter; at least one further second optical input, equal in number to the at least one further first optical output, each of the at least one further second optical input corresponds to one of the at least one further second optical output and coincides in location with the corresponding one of the at least one further second optical output, so that in each case a further second measuring beam is created on the surface by at least a partial reflection of a further second illumination beam arriving in the further first optical input after passing through the imaging optic and after reflection at the beam splitter; at least one further first light detector, equal in number to the at least one further first optical input, each adapted to record the intensity of a further first measurement beam; and at least one further second light detector, equal in number to the at least one further second optical input, each adapted to record the intensity of a further second measurement beam, wherein all further light detectors are also coupled to the evaluation unit so that, from a comparison of the intensities of the further measurement beams, the distance between the sensor and at least one scanning point on the surface, equal in number to the at least one further first optical inputs, is adapted to be determined.