Diagnostic X-ray installation for radiography and fluoroscopy

Claim 1

A diagnostic X-ray installation for radiography and fluoroscopy, said installation comprising an X-ray tube for supplying X-ray energy along an X-ray beam path; an X-ray spotfilm device for positioning an X-ray film in the X-ray beam path during radiography so as to effect exposure of successive subdivisions of the film in accordance with a selected film exposure format; an x-ray image intensifier television chain including an X-ray image intensifier arranged in the X-ray beam path for receiving an X-ray image during fluoroscopy and for supplying a corresponding optical image, a television camera optically coupled with said X-ray image intensifier for supplying a video signal in accordance with the optical image supplied by said X-ray image intensifier during fluroscopy, and a monitor coupled with the television camera for effecting display of the video signal therefrom as a television picture; a control unit connected with said spotfilm device for controlling the exposure of the X-ray film in the X-ray beam path in accordance with a selected film exposure format and having film format setting means for selecting film format setting values characterizing the desired film exposure format of the X-ray exposures to be made on the X-ray film of the spotfilm device during radiography; a signal generator for generating signals operable to control the monitor and having an output, the film format setting means being connected with the signal generator, a mixing stage arranged between the television camera and the monitor, said mixing stage receiving a signal generator output signal from the output of the signal generator which is dependent upon the selected film format setting values at said film format setting means and being operable to superimpose said signal generator output signal on the video signal delivered by the television camera for the purpose of fading-in a representation of the selected film format setting values into the television picture of the monitor, said signal generator supplying as said signal generator output signal a picture generating signal for producing a symbolic pictorial display representing graphically the selected film exposure format and the progress of the X-ray exposures during radiography so that said symbolic pictorial display is faded into the television picture on said monitor, for graphically representing operating status during radiography.