Three-dimensional shape measurement using grating patterns form an optical spatial modulator

  • Tsujioka, Katsumi (Faculity of Radiological Technology, Fujita Health University, School of Health Sciences) ;
  • Ito, Hiroshi (Department of Information Network Engineering, Aichi Institute of Technology) ;
  • Furuhashi, Hideo (Department of Information Network Engineering, Aichi Institute of Technology) ;
  • Higa, Shuntaro (Department of Information Network Engineering, Aichi Institute of Technology) ;
  • Hayashi, Niichi (Department of Information Network Engineering, Aichi Institute of Technology) ;
  • Yamada, Jun (Department of Information Network Engineering, Aichi Institute of Technology) ;
  • Hatano, Kazuo (Department of Information Network Engineering, Aichi Institute of Technology) ;
  • Uchida, Yoshiyuki (Department of Information Network Engineering, Aichi Institute of Technology)
  • 발행 : 1994.10.01

초록

An automatic measuring system of three dimensional shape by a projection method with grating pattern from in optical spatial modulator has been developed. The characteristics of the system were studied. This system is composed of a projector, an optical spatial modulator, a CCD camera, and computer. A liquid crystal is used as the optical spatial modulator. The grating patterns that ire projected on the surface of the object are controlled by the computer connected with the optical spatial modulator. The projector patterns are measured by the CCD camera. The data are transferred to the computer. After a transformation into line data, the data are analyzed to obtain the coordinate of the surface of the object. This system has advantages as follows. (1) It is possible to capture the surface topography without any contact. (2) The time required for the measurements is shorter than the light-section method. (3) An optical spatial modulator using a liquid crystal is possible to control the grating patterns accurately by a computer. Surfaces of a plate and a cylinder were measured. The threshold level had an influence on the measurement. It was shown that this system has adequae accuracy in the measurements.

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