Patent Publication Number: US-4546489-A

Title: Single tank X-ray diagnostic generator

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to X-ray diagnostic generators, and in particular to such generators wherein all components are contained in an oil filled receptacle. 
     2. Description of the Prior Art 
     An X-ray diagnostic generator is described in German Utility Model No. 7,935,945 corresponding to U.S. Pat. No. 4,400,822 of H. Kuehnke and M. Rattner issued on Aug. 23, 1983, in which a single focus X-ray tube, two high voltage transformers for heating the X-ray tube, and the components of two doubler circuits respectively connected to the secondaries of the high voltage transformers are all contained in a single oil-filled receptacle having a radiation exit window for the X-rays. The receptacle also contains a transformer for the filament supply voltage disposed at one end of the X-ray tube. The two high voltage transformers are also disposed adjacent to the X-ray tube and are arranged symmetrically with respect to the radiation exit window in close proximity to the receptacle wall. The rectifiers and capacitors are disposed above the X-ray tube and are also arranged symmetrically relative to the radiation exit window. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an X-ray diagnostic generator having a double focus X-ray tube wherein all components associated with the operation of the X-ray tube are arranged in a single receptacle in such a manner that the filament transformers for the double focus X-ray tube are disposed in the receptable in a space-saving manner. 
     The above object is inventively achieved wherein the two filaments supply transformers are adjacently arranged in the receptacle at one end of the X-ray tube. The single oil-filled receptacle also accommodates all of the other high voltage components for operating the X-ray tube. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a circuit diagram of an X-ray diagnostic generator having a double focus X-ray tube. 
     FIG. 2 is a front view of the components of an X-ray diagnostic generator of the type shown in FIG. 1 arranged in a single receptacle in accordance with the principles of the present invention. 
     FIG. 3 is a side view of the components arranged in the receptacle shown in FIG. 2. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An X-ray diagnostic generator having a double focus X-ray tube 1 is shown in FIG. 1. The double focus X-ray tube 1 is connected in series with four high voltage capacitors 2, 3, 4 and 5. A circuit node 9 between the capacitors 3 and 4 is connected to ground. The circuit also includes two high voltage rectifiers 6 and 7 which form a voltage doubler circuit in combination with the capacitors 2 and 3 for the output voltage of a high voltage transformer 8. The voltage between circuit nodes 9 and 10 is twice as great as that of the secondary voltage of the high voltage transformer 8. In the same manner, capacitors 4 and 5 in combination with high voltage rectifiers 11 and 12 form a doubler circuit for the output voltage of another high voltage transformer 13. The voltage between the circuit nodes 9 and 14 is twice as great as the secondary voltage of the high voltage transformer 13. Thus, the voltage supplied to the double focus X-ray tube 1 is four times the value of the secondary voltage of one of the high voltage transformers 8 or 13. 
     As also shown in FIG. 1, the double focus X-ray tube 1 has two filaments 20 and 21 which are respectively associated with the two foci of the X-ray tube. The filament 20 is heated by a filament supply transformer 19a and the filament 21 is heated by a filament supply transformer 19b. 
     A physical realization and arrangement of the components shown in the circuit of FIG. 1 is shown in FIG. 2 wherein all of the components are disposed within a single oil-filled receptacle 15. The receptacle 15 consists of a base plate 16 and a housing 17, shown in phantom in FIG. 2 in order to view the arrangement of the components inside the receptacle. The housing 17 is connected in fluid-tight relation to the base 16. 
     The double focus X-ray tube 1 emits X-rays through a radiation exit window 18. The two high voltage transformers 8 and 13 are arranged adjacent to the double focus X-ray tube 1 and are symmetrically disposed with respect to the radiation exit window 18 in close proximity to the walls of the housing 17. The high voltage rectifiers 6 and 7 and the high voltage capacitors 2 and 3 associated with the high voltage transformer 8 are disposed above the double focus X-ray tube 1 on one side of a center plane of the generator, and the high voltage rectifiers 11 and 12 and the high voltage capacitors 4 and 5 associated with the high voltage transformer 13 are disposed above the transformer 13 on the other side of the center plane of the generator. The rectifiers 6, 7, 11 and 12 are mounted on respective plates comprised of insulating material. The capacitors 2 and 3 and the capacitors 4 and 5 are disposed symmetrically with respect to the radiation exit window 18, as are the rectifiers 6 and 7 and the rectifiers 11 and 12. The rectifiers and capacitors are supported by the upper ends of the high voltage transformers 8 and 13 a distance above the base plate 16. 
     A side view of the generator is shown in FIG. 3 with the housing 17 removed showing the two filament supply transformers 19a and 19b for the filaments 20 and 21. The transformers 19a and 19b are disposed adjacent to one another at one end of the double focus X-ray tube 1, which is the left end with respect to FIG. 2. The high voltage transformers 8 and 13 and the filament supply transformers 19a and 19b have respective vertical axes. The high voltage transformers 8 and 13 are mounted with their vertical axes in a common vertical plane, and the filament supply transformers 19a and 19b are mounted with their vertical axes in another common vertical plane, which is substantially perpendicular to the common vertical plane of the transformers 8 and 13. 
     The respective primary windings of the high voltage transformers 8 and 13 can be fed from an inverter with a frequency in the kilohertz range of between one and five kHz. The high voltage transformers 8 and 13 may thus be designed small and light-weight. 
     Although modifications and changes may be suggested by those skilled in the art it is the intention of the inventors to embody within the patent warranted hereon all changes and modifications which reasonably and properly come within the scope of their contribution to the art.