Abstract: An X-ray radiographing apparatus includes a power assist device for causing a driving mechanism to generate force for assisting that force which is added to a handle assembly of a spot film device in a direction, so that the spot film device is moved by the sum of both forces in the direction. The movement of the handle assembly is detected by a pressure sensor, so that the detecting signal responsive to the movement is outputted to a control circuit. A driving signal responsive to the detecting signal is supplied from the circuit to the driving mechanism, so that the spot film device is moved in the direction. A component of the weight of the handle assembly is balanced with that of a counter weight, whereby the pressure sensor is prevented from being wrongly operated by the component of the weight of the handle assembly. The width of blind zone of the pressure sensor can be made narrower. The response speed of the spot film device can be made narrower.

Abstract: A spot film device suitable for use with the radiographic system and having a device for carrying and oscillating a grid which serves to absorb X-rays scattered from an object to be radiographed. Rotation force generated by a motor is used not only to move the grid between radiographic and parking positions but also to oscillate the grid. This enables the grid carrier system to be made comparatively simple in construction. In addition, the grid is oscillated over a certain range by the rotation force transmitted from the motor, so that comparatively high reliability can be guaranteed in oscillating the grid.