Apparatus for inspecting surface defects with regularly reflected light and peripherally scattered light

A defect inspection apparatus for inspecting a surface defect of an object, comprising:

• a light emitting device for emitting a light towards the object to linearly scan the object;
• a light receiving unit for receiving a reflected light from the object, the reflected light containing a regularly reflected light and a peripherally scattered light, the light receiving unit comprising:
• a focusing lens for focusing the regularly reflected light on a center region in an image-forming plane and the peripherally scattered light on a peripheral region which spreads concentrically outside the center region;
• a first light-receiving member for receiving said regularly reflected light in said center region and for converting a quantity of the regularly reflected light in the image-forming plane to a first electric signal;
• and
• a second light-receiving member for receiving said peripherally scattered light in said peripheral region and for converting a quantity of the peripherally scattered light in the image-forming plane to a second electric signal;
• and
• a determining unit for determining the surface defect in accordance with the first electric signal and the second electric signal, the determining unit comprising:
• a comparing section for comparing the first electric signal with the second electric signal to generate a comparison signal;
• and
• a determining section for determining a presence of the surface defect in accordance with the comparison signal.