Method and system for moiré profilimetry using simultaneous dual fringe projection
AssigneesSan Diego State University (Sdsu) Foundation, Dba San Diego State University, Centro De Investigaciones En Optica A.C.
InventorsSungbum KANG, Sotero ORDOÑES NOGALES
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Abstract
In alternative embodiments, provided are moiré profilometry methods for analyzing a topography of an object comprising use of dual patterns that are simultaneously projected onto a surface of the object from two symmetric directions. In alternative embodiments, the projected dual patterns superimpose and generate a fringe pattern that contains a moiré pattern, the moiré pattern having a phase that is modulated according to the topography of the object. In alternative embodiments, the moiré pattern is extracted from the fringe pattern using a spatial or temporal method, and the phase is demodulated from the extracted moiré pattern using a spatial or temporal method.
Claims26
A moiré profilometry method for analyzing a topography of an object, the method comprising:
- simultaneously projecting dual patterns onto a surface of the object from two symmetric directions, the projected dual patterns superimposing and generating a fringe pattern that contains a moiré pattern, the moiré pattern having a phase that is modulated according to the topography of the object;
- extracting the moiré pattern from the fringe pattern using a spatial or temporal method;
- and
- demodulating the phase from the extracted moiré pattern using a spatial or temporal method.
A system for moiré profilometry comprising:
- first and second projectors having exit pupils disposed along a first plane that is separated by a distance from a reference plane, the first and second projectors being configured to simultaneously project dual patterns onto a surface of an object disposed between the reference plane and the first plane such that the projected dual patterns superimpose and generating a fringe pattern that contains a moiré pattern, the moiré pattern having a phase that is modulated according to the topography of the object;
- an imaging apparatus having an entrance pupil coplanar with the exit pupils of the first and second projectors, the entrance pupil being configured to receive a reflection of the fringe pattern from the object;
- a processor coupled to the imaging apparatus and configured to:
- extract the moiré pattern from the fringe pattern using a spatial or temporal method;
- and
- demodulate the phase from the extracted moiré pattern using a spatial or temporal method.
Dependencies are inferred from the claim text.