Shadow moire using non-zero talbot distance
October 19, 2025. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3858981 Optical record carrier scanning apparatus with scanning beam focus error detection Automatic focusing system with dual diffraction gratings and converging means Apparatus and method for optically measuring a surface Method and apparatus for measuring thermal warpage System for optically measuring the surface contour of a part using more fringe techniques Portable moire interferometer and corresponding moire interferometric method Circuit for machine-vision system Shadow moire surface measurement using Talbot effect Method and apparatus for detecting objects Patent #: 6841780 InventorsAssigneeApplicationNo. 11252789 filed on 10/19/2005US Classes:356/605, Moire356/618, Moire250/237G, Gratings (moire fringes)356/512, By wavefront detection369/44.24, Means to mask or shield a portion of the beam250/201.5, With optical storage medium; e.g., optical disc, etc.356/619, Quadrature detection356/35.5, By light interference detector (e.g., interferometer)250/205, Controlling light source intensity250/341.1, With irradiation or heating of object or material351/208Having means to detect proper distance or alignment (i.e., eye to instrument)ExaminersPrimary: Nguiyen, Tuan H.Attorney, Agent or FirmInternational ClassG01B 11/24AbstractA method for measuring deformation in specimens is provided. The method includes providing a shadow moiré system, the shadow moiré system including an illumination source, a reference grating and an image capture device and providing a specimen. The method further includes determining a selected distance between the specimen and the reference grating, and illuminating the specimen with light from the illumination source directed through the reference grating onto the specimen, thereby forming shadow moiré fringes onto the specimen. The method further includes capturing an image of the shadow moiré fringes by the image capture device.Other References
Field of SearchCoded scaleLine of light projected Position transverse to viewing axis Position of detected arrangement relative to projected beam Quadrature detection Focus POSITION OR DISPLACEMENT DIMENSION Special mark or target on object Scan By focus detection Occulting a projected light beam Moire Silhouette Triangulation Pattern is series of non-intersecting lines Triangulation Having scale or grid By specular reflection Projection of structured light pattern SHAPE OR SURFACE CONFIGURATION Scan By stereo Moire By projection of coded pattern Gratings (moire fringes) With irradiation or heating of object or material Photocell controls its own optical systems Plural radiant energy responsive devices Selective energization of the load devices Discharge control discharge device load controlled by the radiant energy responsive device Plural load devices Electric switch controlled by the radiant energy responsive device Load device irradiating the radiant energy responsive device Radiant energy responsive load device Selective electric switch controlled by the radiant energy responsive device Radiant energy control of an electric discharge device in the supply circuit of the load device Radiant energy controlled regulation of the current supply for the load device Discharge control discharge device in the supply circuit | |
