Patent ID: 6104481
Filing Date: 2000-08-15
Classification: G01N

Abstract:
A surface inspection apparatus comprising:a light source portion for emitting a light wave of a first wavelength and a light wave of a second wavelength;a first irradiating optical system for directing a light beam of a first wavelength onto the surface of an inspected body in a first angle of irradiation;a second irradiating optical system for directing a light beam of a second wavelength onto the surface of the inspected body in a second angle of irradiation different from the first angle of irradiation and at the same time said light beam of the first wavelength is directed by the first irradiating optical system;a first photosensing optical system for sensing in a first photosensing direction scattered light from the surface of the inspected body irradiated by said first irradiating optical system;a second photosensing optical system for sensing in a second photosensing direction scattered light from the surface of the inspected body irradiated by said second irradiating optical system;a first photosensing portion for converting the scattered light of the first wavelength sensed by said first photosensing optical system into a first sensed-light signal;a second photosensing portion for converting the scattered light of the second wavelength sensed by said first photosensing optical system into a second sensed-light signal;a third photosensing portion for converting the scattered light of the first wavelength sensed by said second photosensing optical system into a third sensed-light signal;a fourth photosensing portion for converting the scattered light of the second wavelength sensed by said second photosensing optical system into a fourth sensed-light signal;a displacement portion for displacing said inspected body and the light beams emitted from said irradiating optical systems relative to each other; anda signal processing portion for discriminating inspected objects on the basis of said first to fourth sensed-light optical signals.