For radiating-the transmission householder method and a transmission assist device of irradiation devices, the radiation-irradiation devices position for keeping a radiation source can be set, obtain when be imaged, a suitable position and a radiographic imaging apparatus are obtained. Around radiation-irradiation devices, transmitting auxiliary device includes wherein about the radiation image recording medium in a movable range of a radiation source holding unit and a workspace, one radiation image can be used, one radiation source can be set in radiation-irradiation position setting one target position of radiation-irradiation devices for that can be fixed, detection one present position of radiation-irradiation devices is used for, detect being used for for a position of an obstacle, and it is used for, it informs that radiation-irradiation devices of target position transmit a user of help, it is with the target position of obstacle, present position, and based on position. Target position time synchronization method, present position detecting element, and obstacle location detection device is made of video camera (28A to 28D) and a control unit (22), notification means are made of video camera (28A to 28D), control unit (22), a monitor (23) and a loudspeaker (18).
