| 摘要 |
Method and apparatus for detecting foreign matters in liquids by irradiating light to a transparent container in which foreign matters are suspended and swirled together with the content liquid, and by measuring the change of transmitted light by individual units of a group of small light receivers. The change of transmitted light due to the displacement of the liquid surface is detected by the small light receivers, and the detection signals are taken up as DC components. In contrast, the change of transmitted light due to moving foreign matters is detected by the small light receivers, and the detection signals are taken up as AC components by means of capacitors. When the detection signal of the liquid surface is lower than the preset standard value, the small light receiver corresponding to the liquid surface is inhibited to issue an output, regardless of detection of foreign matters. |
