Method and system for moiré profilimetry using simultaneous dual fringe projection

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;
• wherein the extracting uses a temporal extraction method and the demodulating uses a temporal phase demodulation method.

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;
• wherein the extracting uses a spatial filtering method;
• and wherein the spatial filtering method further comprises determining a temporal sequence of the fringe pattern.

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;
• wherein the demodulating uses a temporal phase demodulation method;
• and wherein the temporal extraction method uses a phase shifting algorithm (PSA).

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;
• wherein the demodulating uses a temporal phase demodulation method that includes using a phase shifting algorithm (PSA).

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;
• wherein the extracting uses a spatial filtering method and the demodulating uses a temporal phase demodulation 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;
• wherein the extracting uses a temporal extraction method and the demodulating uses a temporal phase demodulation 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;
• wherein the extracting uses a spatial filtering method;
• and wherein the spatial filtering method further comprises determining a temporal sequence of the fringe pattern.

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;
• wherein the extraction uses a temporal extraction method;
• and wherein the temporal extraction method uses a phase shifting algorithm (PSA).

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;
• wherein the demodulating uses a temporal phase demodulation method that includes using a phase shifting algorithm (PSA).