Patent ID: 8212997
Filing Date: 2012-07-03
Classification: G01B

Abstract:
1. A chromatic confocal point sensor optical pen operable to provide a signal usable to measure a distance to a surface, the chromatic confocal point sensor optical pen comprising: a housing; an aperture that outputs source radiation and receives reflected radiation; and a multi-stage optical configuration arranged along an optical axis of the chromatic confocal point sensor optical pen to receive the source radiation from the aperture, output it toward the surface as a focused measurement beam having axial chromatic dispersion, receive reflected radiation from the surface and focus the reflected radiation proximate to the aperture with axial chromatic dispersion, wherein: the multi-stage optical configuration comprises a plurality of axially dispersive focusing elements comprising: at least the first and last axially dispersive focusing elements provide respective amounts of axial chromatic dispersion which contribute to increase the overall axial chromatic dispersion of the measurement beam.