| 摘要 |
PURPOSE:To detect surely whether a core bar is present or not by arranging a light projecting optical fiber and a light receiving optical fiber adjacently to each other and receiving the light, which is projected from the light projecting optical fiber and is reflected on a work or the like, by a light receiving optical fiber. CONSTITUTION:A device consists of a light projecting optical fiber 2, a light receiving optical fiber 3, a core bar R, work W a detector 5, an alarm buzzer 6, etc. The radiated light is reflected on a core bar R, a cushion rubber C, etc., and a part of this reflected light is made incident on the light receiving optical fiber 3. This reflected light is made incident on the detector 5 and is converted photoelectrically in accordance with the incident luminous flux; and since the output level for the presence of the core bar R is preliminarily set to the detector 5, the alarm buzzer 6 is sounded by comparing discrimination if a level lower than this level is inputted, that is, the core bar R is absent. Thus, the presence/absence of the core bar R is detected. |
