Abstract: The invention relates to a method of controlling the exposure of an X-ray image. Starting values for the tube current, the tube voltage and the exposure duration are hereby set on the X-ray tube (10). Following the start of the exposure, the resultant dose rate is measured by a sensor (30, 31) and made available to a control system (100, 200, 300). In order to achieve a predetermined dose for the X-ray image, the control system adjusts the following variables in succession: the tube current within a current range; if applicable, the exposure duration within a time slot; the tube voltage within a voltage range; the exposure duration within the time slot. A rapid controlling of the tube current is enabled, preferably by the pulse-width modulation of the counter-voltage at the control grid of the X-ray tube.

Abstract: The invention relates to a method of controlling the exposure of an X-ray image. Starting values for the tube current, the tube voltage and the exposure duration are hereby set on the X-ray tube (10). Following the start of the exposure, the resultant dose rate is measured by a sensor (30, 31) and made available to a control system (100, 200, 300). In order to achieve a predetermined dose for the X-ray image, the control system adjusts the following variables in succession: the tube current within a current range; if applicable, the exposure duration within a time slot; the tube voltage within a voltage range; the exposure duration within the time slot. A rapid controlling of the tube current is enabled, preferably by the pulse-width modulation of the counter-voltage at the control grid of the X-ray tube.

Abstract: The invention relates to a method for exposure control which is intended notably for dynamic X-ray examinations of an object involving a varying X-ray absorption as well as to an X-ray generator which includes an automatic exposure control unit for carrying out such a method. The method and the device are characterized notably in that an exposure kV start voltage and a maximum exposure time Tmax (for example, 100 ms) can be defined; in order to avoid motional unsharpness in the image, these variables may not be exceeded.

Abstract: The invention relates to an X-ray system/generator in which after the end of an X-ray exposure the grid of th X-ray tube is blocke4d as long as the X-ray exposure is read out from a detector (or as long a film or a PCR is removed from the X-rays). After read out, the grid is released so that the system capacitance may be discharged via the X-ray tube. Thereby over-exposure due to energy stored in the sytem- and cable capacities is avoided (which is a problem especially for thin objects), and the system may be switched from a tube with grid to a tube without grid without problems.

Abstract: The invention relates to an X-ray system/generator in which after the end of an X-ray exposure the grid of th X-ray tube is blocke4d as long as the X-ray exposure is read out from a detector (or as long a film or a PCR is removed from the X-rays). After read out, the grid is released so that the system capacitance may be discharged via the X-ray tube.

Abstract: The invention relates to a method for exposure control which is intended notably for dynamic X-ray examinations of an object involving a varying X-ray absorption as well as to an X-ray generator which includes an automatic exposure control unit for carrying out such a method. The method and the device are characterized notably in that an exposure kV start voltage and a maximum exposure time Tmax (for example, 100 ms) can be defined; in order to avoid motional unsharpness in the image, these variables may not be exceeded.

Abstract: The invention relates to an X-ray device which includes a primary diaphragm device (3) for limiting the X-ray beam and a control circuit (10) for automatic exposure control, which control circuit includes a detector (9) with at least one measuring field (31) which measures the X-ray dose rate. Whereas in the case of customary exposure control systems the X-ray dose is increased when the radiation beam is strongly limited so that parts of the measuring field (31) are not exposed, which could lead to overexposed X-ray images, the X-ray device according to the invention is provided with means (12, 14, 15, 16, 17) for determining a correction value (K) which is dependent on the dimensions of the exposed area (33) of the measuring field (31) and acts on the control circuit (10) in such a manner that an increase of the X-ray dose is even avoided in the case of a partly non-exposed measuring field (31).