Patent ID: 9733196
Date: 2017-08-15
CPC Classifications: G01N

Claim:
1. An upper surface foreign material detecting device of an ultra-thin transparent substrate, comprising: a light source part irradiating light to a transparent substrate and irradiating light so as to be inclined at a Brewster angle corresponding to a material of the transparent substrate; a first detecting part detecting scattered light of a foreign material attached to an upper surface of the transparent substrate by the irradiated light; a second detecting part detecting scattered light of a foreign material attached to a lower surface of the transparent substrate by the irradiated light; and a control part determining that the foreign material which detected through the first detecting part and the second detecting part is a foreign material attached to the upper surface of the transparent substrate when a size of the foreign material detected through the first detecting part is larger than a size of the foreign material detected through the second detecting part, and determining that the foreign material is a foreign material attached to the lower surface of the transparent substrate when a size of the foreign material detected through the first detecting part is smaller than a size of the foreign material detected through the second detecting part.