A Concentric Circle Scanning Technique for Large Area Inspection

Technology

This technology is an optimized rotational sampling method that allows fast and uniform acquisition of image information on a circular surface. The technique has demonstrated the capability to increase sampling speed by 11.5% while reducing distortion error by 50%. Circular scanning method combined with SR techniques can increase the achievable resolution of existing scanners with large field of vision, without additional hardware.  

Problem Addressed

Large area scanning and super high resolution (SR) imaging of surfaces traditionally relies on the translation of results obtained by scanning and sampling in Cartesian coordinates. These techniques require complex hardware and/or software methods to ensure low vibration, fast scanning and high precision, and have issues such as registration errors induced by poor motion estimation, limited recovery of high frequencies in non-lateral dimensions, and vibration induced image degradation in some sensitive devices. Existing rotational sampling methods suffer from sparse data and variation in the outer radii as a result of uniform Polar sampling.   

Advantages

• Higher speed and attenuated transient behavior for large area inspections
• Minimized errors when using circular scanning trajectory to generate Cartesian composite image
• No tradeoff between resolution and field of vision
• Reduced vibration, higher speed, and easier control
• Compensates for hardware limitations such as motor speed and resonant frequency issues
• Increased resolution of existing scanners with large field of vision without additional hardware