摘要 |
An inspection system for detecting surface flaws in a transparent element which includes a source of electromagnetic radiation, such as a laser beam or visible light, with the radiation beam directed edgewise into the transparent element to be inspected at such an angle that the resulting internal angle is larger than the critical angle. This ensures that substantially all of the radiation will stay within the transparent element and exit through an opposing edge of the transparent element unless a surface flaw is encountered, in which case a portion of the radiation will exit the transparent element through the surface of the transparent element. The system includes a detector, such as a line or matrix charge coupled device, capable of detecting the portion of the radiation which exits the transparent element through the surface of the transparent element and of producing signals corresponding to the exiting radiation.
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