| 摘要 |
PURPOSE:To detect even a fine defective automatically with high reliability by dipping a press molding to be inspected in light transmissive liquid and investigating optically whether or not an air bubble is produced at a defective part. CONSTITUTION:A light source part is arranged facing one end of a tank body 1 made of a transparent material and a photodetection part 3 is also arranged on the other side. The projection part projects linear luminous flux with length lthrough a slit 2f and the photodetection part is equipped with a linear image sensor 3a which generates a light quantity distribution measurement signal. The press molding A is dipped in the light transmissive dipping liquid B in the tank body 1. At this time, if the molding A has a defective, as air bubble leaving the defective part moves up in the dipping liquid and crosses the parallel luminous flux. This air bubble functions as a concave lens, so a shade part of light is formed at a position corresponding to the air bubble and it is decided that a shade light signal wave corresponding to it is present in the light quantity distribution measurement signal wave of the linear image sensor, thereby confirming that the press molding A has the defective.
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