| 摘要 |
In an exemplary embodiment, radiography and fluoroscopy is carried out by a film cassette, an image intensifier television chain and a circuit for the automatic influencing of parameters determining the x-ray image quality, which circuit exhibits a radiation sensor, and a comparator for the comparison of a nominal setpoint value with the actual value delivered by the sensor, in which analog to digital converters are provided for the formation of an electric signal corresponding to the electrode voltages of the x-ray image intensifier, which electric signal is supplied in the form of an address to a memory in which the dependency of the conversion factor of the x-ray image intensifier upon the electrode voltage is stored. In addition, a converter is provided for the formation of an electric signal which is dependent upon the aperture of the x-ray collimator, which electric signal forms the address for a memory in which the dependency of the background of the x-ray image intensifier upon the aperture of the collimator determining the image format is stored. The output signals of the two memories are superimposed in an adder on the nominal setpoint value for the control loop.
|
