3D MEASURING APPARATUS USING ON-AXIS DIGITAL HOLOGRAPHY

摘要

The present invention relates to a 3D measuring apparatus using the On-axis digital holography method, a first image pick-up unit and the second imaging unit; And a light source for generating a linearly polarized beam having a vertical polarization and horizontal polarization directions inclined 45 with respect to the polarization directions, respectively; And the first beam splitter to split the linearly polarized output beam mutually perpendicular to the first optical path and a second optical path from the light source direction; The first is disposed on the optical path, the linearly polarized output beam to a measurement target object direction, the linearly polarized beam is reflected from the measurement object the first beam splitter, the measuring beam direction is formed with the output from the first beam splitter and a second beam splitter for dividing the second output optical path and parallel to the third optical path direction; It is disposed on the second path and the quarter-wave plate to polarize the light into circularly polarized light beam having a 90 phase difference to the linearly polarized beam outputted from the first beam splitter; The second optical path is disposed on the mirror and the output based on the direction of the circular polarized beam and the circularly polarized light beam is reflected from the reference mirror to the reference direction of the first beam splitter, the beam formed from the quarter-wave plate a third beam splitter and outputting divided into a first optical path and parallel to the fourth optical path direction; Disposed on the third optical path and said second optical path intersecting the position, the measurement beam from the first imaging unit and the second of the reference beam from the third beam splitter from the second beam splitter and a fourth beam splitter for dividing the output direction of the image pickup section; And the vertical line for output to the first image pick-up polarizer is arranged between the first imaging unit and said second beam splitter to pass through the vertical polarization components of the interference light formed by the interference of the measuring beam and the reference beam; The second image pickup section and is disposed between the beam splitter and the fourth polarizing plate horizontal line output to the second image pick-up is passed through the horizontal polarization component of the interference light; The measuring beam and the first beam splitter is output to the rough direction of the first beam splitter from the second beam splitter, the third beam of the first beam splitter, the direction of the reference beam from the splitter output is the quarter-wave plate a third sensing unit for sensing the reference beam passed through the beam splitter to the first linearly polarized state passes through; And the third on the basis of the reference beam and the measuring beam which is picked up by the image pickup unit to extract the DC applied to the item and the digital holography, the extracted DC item from the first image pickup unit and picked up by the second image capture unit and using a pair of the hologram is characterized in that a control unit for measuring the surface shape of the measurement object.