| 摘要 |
<p>A description is given of a method of determining the speed of threads, which exhibit irregularities when they are observed with forward-diffused light or with light emitted by fluorescence, featuring the following stages: - illumination of the thread on two points which are 0.2 to 20 cm apart so as to define, for each of the two points, a height focus no greater than 100 mu m and a width focus somewhat greater than that of the height, so that the whole section of the thread is illuminated; - conveyance and detection of the light from each of the two points so as to generate a signal for each of the two points, dependent on the thread irregularities; - amplification of the two signals; - determination of the time that the thread takes to travel the distance between the two points, and hence its speed, by means of a function of correlation (fc) between the two amplified signals.</p> |
