PROBLEM TO BE SOLVED: To provide a signal communication system capable of always exactly determining whether or not selection of combination of a radiation source and a radiation image detector used for image-capturing is correct.SOLUTION: An X-ray image-capturing system 2 comprises: one X-ray source 15 two electronic cassettes 12 and a signal relay device 32. A transmitter 30 provided to the X-ray source 15 sends out a wireless detection signal for detecting whether or not an electronic cassette 12 selected to be used for image-capturing and the X-ray source 15 are arranged so as to face each other. The signal relay device 32 includes a relay reception unit 35 and a relay transmission unit 36 which are able to be arranged at optional locations. The relay reception unit 35 is attached to a wall surface 39 of an image-capturing room and receives the detection signal sent out by the transmitter 30 to transmit the received detection signal to the relay transmission unit 36. The relay transmission unit 36 is attached to a position on a standing posture image-capturing table 17 and a lying posture image-capturing table 18 which are facing a receiver 31 of the electronic cassette 12, and the relay transmission unit 36 wirelessly transmits the detection signal received by the relay reception unit 35 to the receiver 31.COPYRIGHT: (C)2015,JPO&INPIT【課題】撮影に使用する放射線源と放射線画像検出装置の組み合わせの選択が正しいか否かを常に正確に判定することができる信号通信システムを提供する。【解決手段】X線撮影システム2は、1台のX線源15と2台の電子カセッテ12と信号中継装置32とを備える。X線源15に設けられた送信機30は、X線源15と撮影に使用すると選択された電子カセッテ12が対向して配置されているか否かを検出する無線の検出信号を発する。信号中継装置32は、任意の箇所に配置可能な中継受信部35および中継送信部36を有する。中継受信部35は、撮影室の壁面39に取り付けられ、送信機30が発する検出信号を受信して中継送信部36に送信する。中継送信部36は、立位、臥位撮影台17、18の、電子カセッテ12の受信機31と対向する位置に取り付けられ、中継受信部35で受信した検出信号を受信機31に無線送信する。【選択図】図4
