Fig. 1. Schematic diagram of the structure of TFT-LCD module and the defects on different layers

Fig. 2. AOI basic principle

Fig. 3. Schematic diagram of multi-sensor AOI system

Fig. 4. Schematic diagram of AOI system structure for inspecting TFT and filter array substrates

Fig. 5. Angle resolution inspection with the techniques of spot canning and multi-channel imaging.(a) Multi-channel scanning imaging principle; (b) image from a document scanner; (c) surface patterns obtained by point scanning with dark field imaging; (d) surface oil stain and fingerprint pattern obtained by point scanning with low angle imaging; (e) surface gradient map obtained by spot scanning with coaxial brightfield imaging

Fig. 6. Principle architecture of block parallel high-speed processing

Fig. 7. Schematic diagram of on-line AOI system mechanism for inspecting mobile backlight model

Fig. 8. Light scattering model on surface

Fig. 9. Typical lighting types. (a) Brightfield lighting; (b) axial brightfield lighting; (c)darkfield lighting; (d) low angle darkfield lighting; (e) diffuse lighting; (f) back lighting

Fig. 10. Comparison of different lighting effects. (a) Brightfield ring light illumination; (b) linear darkfield lighting with low angle; (c) brightfield ring lighting; (d) diffuse lighting

Fig. 11. Angle resolution relationship of surface defects of steel plate with camera and light source. (a) Angle relationship between camera and light; (b) angle resolution of defects

Fig. 12. Color disk showing warm and cool colors

Fig. 13. Lighting color, object feature color and imaging effects

Fig. 14. Imaging effect of red and blue illumination on aluminum alloy bottle cap. (a) Bottle cap to be inspected; (b) effect with red light illumination; (c) effect with blue light illumination

Fig. 15. Positions of ultraviolet, visible and infrared bands in electromagnetic spectrum

Fig. 16. Temperature and infrared radiation spectrum curve

Fig. 17. Comparison of visible and infrared spectra imaging

Fig. 18. Infrared imaging filtering effect. (a) Effect with white light; (b) effect with infrred light

Fig. 19. Infrared light penetration. (a) Effect using 660 nm red light; (b) effect using 880 nm infrared light

Fig. 20. Non thermal infrared vision and thermal infrared AOI technology

Fig. 21. Spectral distribution of UV-LED and mercury lamp

Fig. 22. Comparison of the ability of ultraviolet light to particle scattering. (a) 266 nm; (b) 470 nm; (c) 532 nm; (d) 633 nm

Fig. 23. Differential detection of spray paint on the car body with UV reflection method. (a) Same color presented under visible light; (b) color difference presented under ultraviolet light

Fig. 24. Principle of ultraviolet fluorescence detection

Fig. 25. Stokes shift

Fig. 26. Change of light vector on medium interface

Fig. 27. Reflection and transmission of light on metal surface

Fig. 28. Eliminating the influence of glare or bright spot on reflective surface by polarized imaging. (a) Image without polarizer; (b) image with polarizer

Fig. 29. Reflective polarized lighting and imaging

Fig. 30. Reflective images using ordinary lighting and polarized lighting, respectively. (a) Ordinary lighting; (b) polarized lighting

Fig. 31. Photoelastic effect. (a) Polarization image obtained by photoelastic method; (b) unfiltered image

Fig. 32. Stress and micro crack test with transmission polarization imaging

Fig. 33. Teledyne Dalsa 's four line CMOS polarization camera and imaging results. (a) Teledyne Dalsa's polarized camera; (b) stress measurement results

Fig. 34. Stokes parameter evaluation results

Fig. 35. Propagation characteristics of light in a vertical stratified fluid medium

Fig. 36. Schematic diagram of double field mirror schlieren measurement

Fig. 37. Practical two field mirrors schlieren measurement optical system

Fig. 38. Schematic diagram of direct shadow imaging

Fig. 39. Optical path of laser collimation lighting direct shadow imaging

Fig. 40. Optical path of focus shadow imaging

Fig. 41. Holographic interferometry in AOI. (a) Reference interferogram generation and recording; (b) speckle interference test process

Fig. 42. Five basic holographic interferograms of the surface defect. (a) Bull's eye; (b) groove; (c) bend; (d) displacement; (e) compression

Fig. 43. Digital holography scheme for large field of view

Fig. 44. Comparative digital holography. (a) Recording of a reference object hologram; (b) comparison of the measured object hologram with the reference object hologram

Fig. 45. Schematic diagram of ESPI digital speckle interferometry system

Fig. 46. Schematic diagram of shearing speckle interferometry system

Fig. 47. Shearing speckle interference system based on 4f optical system. (a)Principle of shearing speckle interference optical path based on 4f optical system; (b) traditional fringe pattern; (c) fringe pattern based on 4f optical system

Fig. 48. Defect inspection of aeronautical composite materials. (a) Defect specimen of multilayer composite honeycomb plate; (b) shearographic phase diagram of honeycomb plate defect

Fig. 49. Image processing of defect detection

Fig. 50. Schematic diagram of frequency domain filtering process

Fig. 51. Inspecting the fiber defects on a TFT array surface. (a) TFT array image with a fiber defect; (b) image removed periodic background; (c) pixel grey of the 92th row in time domain; (d) reconstruction results of the 92th row pixels

Fig. 52. TFT array singular value decomposition method. (a) TFT images with defects; (b) the first 10 singular values; (c) reconstructed image; (d) binary image

Fig. 53. Schematic diagram of CNN network architecture