Abstract: A chute for an optical selector has a corrugated bottom surface in order to insure that particulate articles to be selected flow linearly and are dispersed uniformly across the width. The corrugations along the bottom surface of the chute are gentle having a small ratio of height to pitch of corrugation, and such corrugations provide shallow valleys which extend linearly from the upper infeed end of the chute to the lower discharge end. When the particulate articles to be selected flow down the chute, they accordingly flow in a linear way rather than following a curved path, but if the flowing quantity becomes so great as to normally cause a vertical piling up at the discharge end, the particulate articles will move sideways rather than piling up.

Abstract: A cleaning device for a window used in an optical inspection device. The cleaning device removes dust which adheres to the transparent window by means of a dust scraper which contacts the surface of the window so as to enable the dust adhering to the surface of the window to be removed.