| 摘要 |
PURPOSE:To enable accurate detection of the broken state, etc. of a linear object, by detecting, e.g., a breaking of the linear object based on the alternating electrical signal given by a light-receiving device in response to the vibration of linear object between light-emitting and light-receiving devices. CONSTITUTION:A light-emitting device 1 capable of emitting rays of specified quantities and a light-receiving device 3 capable of giving electrical signal corresponding to the quantities of receiving light are set up, facing with each other a linear object ST such as yarn from a fine spinning machine in-between. And, the breaking or existence of said object ST is detected, based on the alternating current electrical signal given by the light-receiving device 3 in response to the vibration of said object ST. |
