Optical inspection of flat media using direct image technology
The invention is directed at a method and system of detecting defects in a transparent media such as a piece of glass. The method comprises the steps of transmitting light from a light source towards the transparent media and then detecting defects in the transparent media by scanning the light as it is reflected or passes through the transparent media. The method and system may operate in any one of a dark field mode, a bright field mode for scanning or a bright field mode for inspecting.
1. A method of detecting a defect in a transparent media comprising the steps of:
transmitting a collimated light beam from a light source to said transparent media;
detecting said defect by scanning said transparent media as said collimated light passes through said transparent media; and
forming an image of the defect directly on an image receiving media, based on light reflected off said defect, regardless of a position said defect in said transparent media
transmitting said image to a film diffuser; and
transmitting said image to an image detector via a Gradient Refractive Index lens array.
2. The method of claim 1 wherein a size of said image is calculated via a Kirchhoff-Fresnel, Fraunhoffer or other diffraction model.
3. The method of claim 1 wherein said step of transmitting said collimated light beam comprises the step of:
transmitting a wavelength collimated light beam.
4. The method of claim 1 wherein said step of transmitting said collimated light beam comprises the step of:
transmitting an incoherent collimated light beam.
5. The method of claim 1 wherein said light source and said image receiving media is above said transparent media.
6. The method of claim 1 wherein said light source is below said transparent media and said image receiving media is above said transparent media.