APPARATUS AND METHOD FOR OPTICALLY MEASURING AN OBJECT SURFACE CONTOUR

摘要

An optical metrology system and method for rapidly and accurately measuring an object surface contour. The optical metrology system measures cross-sections of an object substantially orthogonal to an axis of the object includes a first and second optical assemblies each arranged proximate to opposing sides of a desired section of the object to be measured. The optical assemblies each include at least one source of electromagnetic radiation such as a laser, each configured to project a linear beam on a proximate object surface. The optical assemblies also include a line scan camera fixed relative to the lasers and having a single column of detector elements substantially parallel with the object surface. The camera receives reflections from the object surface which are provided to a controller for processing. The system also includes a first adjustment device for adjusting a distance between the lasers of each assembly and the object. This causes the linear laser beams to intersect each other at a scanning region. The size and configuration of the scanning region is based upon the configuration of the object surface and is substantially aligned with the column of detector elements in the line scan camera. The system also includes a second adjustment apparatus for adjusting a relative position of the object and the optical assemblies along the axis of the object to scan additional sections of the object. Preferably, the line scan camera is a CCD camera and the detector elements are CCD sensing elements. The controller determines the cross-section dimensions of the object at the desired section of the object,