| 摘要 |
PROBLEM TO BE SOLVED: To provide a foreign matter inspection device capable of certainly detecting the foreign matter if the same exists at a bottom portion of a glass bottle.SOLUTION: A foreign matter inspection device comprises: lighting apparatus 2 arranged above a glass bottle 1 to light inside the same from above; and imaging means 3 arranged below the glass bottle 1 to form an image with transmitted light transmitted through a bottom portion 1a of the glass bottle 1. An inverted conical lens 4, which has inverted conical surfaces at both an inner side and an outer side in a radial direction as well as an annular opening 4c at a lower edge of the inverted conical surface at the inner side in the radial direction, is provided between the bottom portion 1a of the glass bottle 1 and the imaging device 3. Thus, light emitted from the lighting apparatus 2 passes through the glass bottle 1 from a shoulder portion 1s thereof to the bottom portion thereof while being reflected a plurality of times on an inner wall surface of the glass bottle 1, and a part of light transmitted through the bottom portion 1a of the glass bottle 1 incidents on the imaging means 3 through the two inverted conical surfaces 4a and 4b at the inner side and outer side in the radial direction of the inverted conical lens 4. |
