Phase-shifting Moiré topography using optical demodulation on liquid crystal matrices

To date, the use of liquid crystal grid projection for profilometric applications is gaining in popularity because of its flexibility. Liquid crystal projection devices allow easy adaption of the grid pitch (and thus sensitivity) in for instance Moire topography, and in-plane translation of the grid position is also readily achieved. However, all methods either use Fourier transform profilometry or digital demodulation in the computer, with the advantage being the measurement speed. The major disadvantage is that the resolution is compromised. Only optical demodulation combined with phase-shifting methods does not yield any resolution. In this paper, we describe a technique which performs this optical demodulation as well as the grid projection with grids on liquid crystal light modulators. This entirely liquid crystal Moire projection profilometer thus achieves higher resolution, flexibility and ease-of-use than the solely LCD grid projection setups. Theory and application examples are given in this paper, and a study is made of different parameters and algorithms influencing the resolution.

[1]  Yu Fu,et al.  Analysis of phase distortion in phase-shifted fringe projection , 2007 .

[2]  D. Meadows,et al.  Generation of surface contours by moiré patterns. , 1970, Applied optics.

[3]  Wolfgang Osten,et al.  Three Methods For The Interpolation Of Phase Values Between Fringe Pattern Skeletons , 1990, Other Conferences.

[4]  W. Decraemer,et al.  Optoelectronic moire projector for real-time shape and deformation studies of the tympanic membrane. , 1997, Journal of biomedical optics.

[5]  Sam Van der Jeught,et al.  Implementation of phase-shifting moiré profilometry on a low-cost commercial data projector , 2010 .

[6]  B. Drerup.  Some Problems in Analytical Reconstruction of Biological Shapes from Moiré Topograms , 1982 .

[7]  W. F. Decraemer,et al.  Phase shift moire apparatus for automatic 3D surface measurement , 1989 .

[8]  D. Bagger-sjöbäck,et al.  Shape and displacement patterns of the gerbil tympanic membrane in experimental otitis media with effusion , 1995, Hearing Research.

[9]  A Asundi,et al.  Fast phase-unwrapping algorithm based on a gray-scale mask and flood fill. , 1998, Applied optics.

[10]  B. Bhushan,et al.  An Optical Profilometer for Surface Characterization of Magnetic Media , 1984 .

[11]  J. Buytaert,et al.  Moiré profilometry using liquid crystals for projection and demodulation. , 2008, Optics express.

[12]  Qian Kemao,et al.  Determination of the best phase step of the Carré algorithm in phase shifting interferometry , 2000 .

[13]  Joris J.J. Dirckx,et al.  Modified temporal-phase-unwrapping method for measuring in real time the out-of-plane displacements of the tympanic membrane of Mongolian Gerbil , 2008 .

[14]  Wei-Hung Su,et al.  Calibration-based two-frequency projected fringe profilometry: a robust, accurate, and single-shot measurement for objects with large depth discontinuities. , 2006, Optics express.

[15]  White light on-axis digital holographic microscopy based on spectral phase shifting. , 2006, Optics express.

[16]  P. Carré.  Installation et utilisation du comparateur photoélectrique et interférentiel du Bureau International des Poids et Mesures , 1966 .

[17]  Anand Asundi.  Novel grating methods for optical inspection , 1991, SPIE Optics + Photonics.

[18]  W. Osten,et al.  Digital Processing and Evaluation of Fringe Patterns in Optical Metrology and Non-Destructive Testing , 2000 .

[19]  Young-June Kang,et al.  A study on the 3-D measurement by using digital projection moiré method , 2008 .

[20]  W. Decraemer,et al.  Automatic calibration method for phase shift shadow moire interferometry. , 1990, Applied optics.

[21]  M. Takeda,et al.  Fourier transform profilometry for the automatic measurement of 3-D object shapes. , 1983, Applied optics.

[22]  Hiroshi Takasaki.  Moiré topography from its birth to practical application , 1982 .

[23]  Pal Greguss,et al.  Optics in Biomedical Sciences , 1982 .

[24]  Grating noise removal in moiré topography , 1990 .

[25]  Karl-Hans Laermann,et al.  Optical methods in experimental solid mechanics , 2000 .

[26]  Huai Min Shang,et al.  Shape measurement by use of liquid-crystal display fringe projection with two-step phase shifting. , 2003, Applied optics.

[27]  Joris J J Dirckx,et al.  Design considerations in projection phase-shift moiré topography based on theoretical analysis of fringe formation. , 2007, Journal of the Optical Society of America. A, Optics, image science, and vision.

[28]  Dennis C. Ghiglia,et al.  Two-Dimensional Phase Unwrapping: Theory, Algorithms, and Software , 1998 .

[29]  Cyril Breque,et al.  Calibration of a system of projection moiré for relief measuring: biomechanical applications , 2004 .

[30]  Haitao He,et al.  Gamma correction for digital fringe projection profilometry. , 2004, Applied optics.

[31]  M. Idesawa,et al.  Interactive Fringe Analysis System: Applications To Moire Contourogram And Interferogram , 1982 .

[32]  Moon-sik Jeong,et al.  Color grating projection moiré with time-integral fringe capturing for high-speed 3-D imaging , 2002 .

[33]  Fu-Pen Chiang,et al.  Moiré techniques, holographic interferometry, optical NDT, and applications to fluid mechanics : Second International Conference on Photomechanics and Speckle Metrology : 22-26 July 1991, San Diego, California , 1991 .

[34]  Maurice Halioua,et al.  Projection moire with moving gratings for automated 3-D topography. , 1983, Applied optics.

[35]  D. Bagger-sjöbäck,et al.  Tympanic membrane displacement patterns in experimental cholesteatoma , 1999, Hearing Research.