| 摘要 |
PURPOSE:To measure the apparent outer diameter of a yarn gathering single yarns such as processed yarn coarse and dense at a high accuracy by employing an image pickup element in an unsaturated area where an output varies in proportion to the quantity of incident light. CONSTITUTION:In an outer diameter measuring section 30, light from a light source 31 turns to an even scattered light with a light scattering plate 32 and irradiates a yarn 1. A light image of the yarn 1 is formed on an image pickup element 36. A front aperture 33 and a rear aperture 35 combines to restricts the optical path and prevents the blurring of the light image due to the aberration of an optical lens 34. An output of the image pickup element 36 is compared with a specified threshold level L with a computation processing section 38 to determine an apparent outer diameter (d) of the yarn 1. As the image pickup element 36 is used in an insaturated area, the output of the image pickup element follows a fine change in the quantity of light due to the single yarns of the periphery. Thus, the apparent outer diameter can be measured at a high accuracy by determining the threshold level L appropriately. |
