Phase Deflectometry for Defect Detection of High Reflection Objects
X.M. Cheng, Tingting Wang, Wenbin Zhu, Baidi Shi, Wei Chen
Abstract
A method for detecting the surface defects of high reflection objects using phase deflection is proposed. The abrupt change in the surface gradient at the defect leads to the change in the fringe phase. Therefore, Gray code combined with a four-step phase-shift method was employed to obtain the surface gradients to characterize the defects. Then, through the double surface illumination model, the relationship between illumination intensity and phase was established. The causes of periodic error interference were analyzed, and the method of adjusting the fringe width to eliminate it was proposed. Finally, experimental results showed the effectiveness of the proposed method.
Topics & Concepts
OpticsInterference (communication)Materials scienceDeflection (physics)Phase (matter)Reflection (computer programming)Phase changeSurface (topology)Computer sciencePhysicsTelecommunicationsGeometryMathematicsChannel (broadcasting)Quantum mechanicsProgramming languageEngineering physicsOptical measurement and interference techniquesIndustrial Vision Systems and Defect DetectionSurface Roughness and Optical Measurements