Fay, Sharpe, Beall, Fagan, Minnich & McKee
Extraneous substance inspection method and apparatus
 In the present invention, an extraneous substance inspection optical system having an extraneous inspection area of a predetermined scanning width in subscanning direction of a matter to be inspected is positioned in such a manner that the extraneous substance inspection area at a moment when the matter to be inspected is started to move in main scanning direction is arranged at a position in the main scanning direction corresponding to a head portion of the matter to be inspected; the matter to be inspected is moved in the main scanning direction to be subjected to a forward scanning for the matter to be inspected to thereby detect possible extraneous substances in the extraneous inspection area; and the matter to be inspected is rotated by 180.degree. after completing the forward scanning, then the matter to be inspected is moved in the direction opposite to the forward scanning to be subjected to a backward scanning, to thereby detect possible extraneous substances in the extraneous substance inspection area. 
Hitachi Electronics Engineering Co., Ltd.
G
G01N
inventional
Tetsuya Hisato Yoshio
Watanabe Nakamura Morishige