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

摘要

Virtually all of the light reflected from an object to be inspected is made incident upon a focusing lens 7, a quantity of light in a regularly reflected light region on an plane P1 where an image is formed by a lens 7 is detected by a photodiode 8, while a quantity of light in a peripherally scattered light region is detected by a photodiode 9. If the quantity of light received (VDET1) in the regularly reflected light region is lower than a first reference value (VREF1) (S1=1), and the quantity of light received (VDET2) in the peripheral scattered light region is higher than a second reference value (VREF2) (S2=1), a determination is made that a defect is present.