US 2009/0021750 A1 · Method and Arrangement for a Rapid and Robust Chromatic Confocal 3D Measurement Technique

Abstract

The invention relates to a chromatic confocal technique method and arrangement for the rapid three-dimensional measurement, in particular, of object shape, more particularly of a tooth in the jaw of a human being with an array of polychromatic point light sources, a planar detector matrix, arranged before means for lateral spectral separation and an objective for object illuminating and recording. According to the invention, spectral defined reference light bundles are generated also using components of the arrays of point light sources for chromatic calibration, wherein said reference light bundles are injected into the detection beam path via a reference bean path for chromatic lateral separation and then focused on the detector matrix as reference image points. Spectral reference points are calculated at the detector matrix positions and sub-matrices for spectral analysis of object light are digitally stored with pixel accuracy by means of the above positions which then serve for obtaining measurement points such that the detector matrix may be completely filled out with oblong sub-matrices, the planar array is arranged on the planar detector matrix rotated about an acute angle to the spectral axis, wherein the rotation is carried out about the optical axis (OA) of the arrangement, such that a connecting line of point light sources on projection thereof in the plane of the detector matrix includes an acute angle there with the spectral axis, the λ-axis.

Claims13

Dependent claims

1-2. (canceled)

A method for achieving a robust, chromatic confocal technique for the three-dimensional measurement of the shape of an object or the shape and position of one or more objects, comprising the following components in the system:

a planar array of polychromatic point light sources, the polychromatic point light sources being adapted to generate a multiplicity of light bundles (B1 to Bi), a beam splitter (11), at least one element (12) having a refractive power that is wavelength-dependent, at least one planar detector matrix (21) in the path of the detection beam, upstream of which detector matrix means (19) for lateral spectral splitting and means (20) for focusing onto the detector matrix are disposed, and a measuring lens (14) for illuminating and imaging the object, wherein spectrally defined reference light bundles are generated for chromatic calibration, which light bundles propagate along the beam path of the polychromatic point light sources and along a reference beam path and are again coupled into the beam leading to the detection means, and, following spectral splitting, are at least approximately focused onto the detector matrix (21) as reference pinpoint images, which are implemented for spectral analysis of the object light.

Dependencies are inferred from the claim text.

Facts

Application

12/223,079Filed 2 Aug 2007

Priority

DE 10 2006 007 170.08 Feb 2006

Published

22 Jan 2009

Term ends

Not estimatedThe source records don’t support an estimate.

Classification5 codes

G01B 11/25
For measuring contours or curvatures: by projecting a pattern, e.g. one or more lines, moiré fringes on the object
G06T 7/521
Depth or shape recovery: from laser ranging, e.g. using interferometry; from the projection of structured light
G01B 2210/50
Aspects not specifically covered by any group under G01B, e.g. of wheel alignment, caliper-like sensors: using chromatic effects to achieve…
G01B
Measuring length, thickness or similar linear dimensions

Method and Arrangement for a Rapid and Robust Chromatic Confocal 3D Measurement Technique

Life of this patent

Method and Arrangement for a Rapid and Robust Chromatic Confocal 3D Measurement Technique

Life of this patent

Abstract

Claims13