| 摘要 |
PURPOSE:To improve response by preventing external influence of a noise, etc., by providing several detection parts to hairpin-shaped photo transmitters parallel to a photo transmission line, in an information detection system for light leakage detection of the photo transmission line. CONSTITUTION:Beltlike area L between initial part 2 and terminal part 3 of photo transmission line 1 is divided into detection sections l1 to ln, in parallel to which photo transmitter 4 bent at bending part 5 is arranged, and detection parts 101 to 10n are provided corresponding to the detection sections. At one terminal of photo transmitter 4, photo-pulse generating part 6 is provided and at the other terminal, photo detecting part 7 is provided. Each detection part, provided with light branch unit 11 at its going path 8 and photocoupler 12 at returning path 9, consists of a pair of units 11 and 12 and space 13 where light can leak. |
