Abstract: A pulsed precision x-ray source includes a miniaturized internally self-shielding x-ray tube and an integral generator contained in a hand-held housing for generating timed bursts of x-ray having regulated energy level. A control grid and focus electrode within the tube enable precise on-off control of an electron beam directed to an x-ray emitting anode. The integral generator system includes an elongated, U-shaped unitary, molded plastic block mounted in the housing and includes a high voltage transformer having primary and secondary annular windings encased in a transformer portion of the block defining a central opening outside of the block for receiving a transformer core therethrough and, a capacitor-diode voltage multiplier stack connected to the secondary winding and having a positive node connectable to the anode and a negative node connectable to the cathode.

Abstract: The invention provides a method and apparatus for obtaining a selectable contrast image in an X-ray exposure. The method comprises applying a controlled high voltage to an X-ray tube in response to a controlled invertor-generated voltage; generating the controlled invertor-generated voltage; driving the invertor in response to a KV control signal; comparing a KV feedback signal with a KV reference signal for developing said KV control signal, and selecting any of a plurality of variable level reference signals as the KV reference signal. The apparatus comprises means for carrying out the foregoing method.

Abstract: The brightness of an X-ray video image during fluorography is maintained at a substantially constant level by a control circuit which varies the X-ray dose in relation to changes in the average brightness of the X-ray image. As the X-ray system approaches the limits of its imaging capability, varying the X-ray dose alone may not yield the desired brightness level. At this point, the gain applied to the video signal is increased to improve the brightness. A linear brightness taper function is used such that, as the level of video gain required to maintain constant brightness increases, the actual video gain increases by a smaller proportional amount. This function results in the brightness of the video image decreasing somewhat as the video gain is required to provide a greater degree of brightness compensation.

Abstract: A filament current regulator for an X-ray generator includes a circuit which compares the actual X-ray tube filament current to a predefined filament current reference value. Another circuit is included which compares the actual X-ray tube excitation voltage, applied across the anode and to cathode of the tube, to a predefined reference voltage value. The regulator adjusts the filament current during a first time interval of an exposure based on only the filament current comparison, and during the remainder of the exposure based substantially on the excitation voltage comparison. The regulator apparatus also integrates the difference between the actual filament current and the reference current value over a given interval during the exposure. The integrated result is employed by the regulator to redefine the filament current reference value.

Abstract: A high-voltage generating device for use with an X-ray tube comprises a converter circuit for rectifying, chopper controlling, boosting and rectifying an A.C. voltage from an A.C. power supply to apply a D.C. voltage to the X-ray tube, a tube-voltage detecting circuit for detecting a tube voltage of the X-ray tube to produce a signal corresponding to the detected tube voltage, a preset signal generator for generating a signal corresponding to a constant voltage, and a feed-back control circuit for controlling the chopper transistor of the converter circuit on the basis of the output of the preset signal generator at the start of operation and on the basis of the output of the tube voltage detecting circuit after the output of the tube voltage detecting circuit has reached a reference value.

Abstract: An x-ray machine in which an electronic network automatically sets the KV for the power to the x-ray tube, by using a transformer with separate secondary windings which can be selectively included in a series circuit through relays controlled by a binary sequence, in response to operator-selected KV control signal, in a system in which the operator selects the mAs setting and the other technic factors (except KV) are automatically selected.

Abstract: A high DC voltage generator for an X-ray tube includes a low voltage rectifier for rectifying a low AC input voltage to produce a low DC voltage, a DC-to-DC converter for converting the low DC voltage into a high DC voltage for the X-ray tube, and a controller for controlling transition characteristics of turning-on and off the X-ray tube. The controller shortens a rising time period of the high DC voltage until a rating anode voltage is applied to the X-ray tube after turn-on operation.

Abstract: Disclosed is an inverter type X-ray apparatus comprising a DC-DC converter for converting a DC voltage into a different DC voltage, an inverter for inverting an output voltage of the DC-DC converter into an AC voltage, a high voltage transformer for transforming an output voltage of the inverter into a higher voltage, a rectifier for converting an AC output voltage of the transformer into a DC voltage, and an X-ray tube to which an output voltage of the rectifier is applied. In the apparatus, the DC-DC converter includes a reactor, a switching element and a capacitor which are interconnected so that the DC-DC converter can generate an output voltage higher or lower than an input voltage.

Abstract: A high voltage generating apparatus for an X-ray tube comprises an inverter for converting a DC voltage into an AC voltage, a high voltage transformer for boosting an output voltage of the inverter, a rectifier for converting an output voltage of the transformer into a DC voltage, and a detector for detecting an X-ray tube voltage to produce an output signal corresponding to the X-ray tube voltage. The output signal of the detector is sampled and held by a sample/hold circuit in synchronism with an operating period of the inverter so that the X-ray tube voltage is controlled in accordance with an error between an output signal of the sample/hold circuit and an X-ray tube voltage set level.

Abstract: Digital radiography apparatus uses a resonance-type high frequency inverter having a main switch in series with an auxiliary switch. An X-ray tube receives the pulsed power from the high frequency inverter, after voltage ampliflication and rectification, emitting pulsed X-rays to a patient. A TV camera obtains X-ray transmission images of the patient, and an image processor generates a visual diagnostic image by subtracting one X-ray transmission image from another. The high frequency inverter circuit is controlled synchronously with the processing operation of the image processor.

Abstract: A voltage signal proportional to the brightness of an x-ray image is derived. In a mA loop the ratio of a reference voltage to brightness is determined. If the brightness ratio does not equal 1 it causes the x-ray tube current controller to adjust current (mA) to eliminate the error. A command proportionate to the ratio is stored until the next image frame. In a kV loop a ratio of the last mA command and a set limit for mA is taken. This error ratio is multiplied by the brightness ratio to provide a kV control ratio indicative of how much of the brightness error the kV loop is obliged to correct. The kV control ratio is corrected for nonlinearity between kV change and brightness change and the resulting command is used to adjust the kV applied to the x-ray tube anode.

Abstract: A control system for the x-ray tube high voltage supply in an x-ray diagnostic installation has a switching device for switching between two circuits for providing an actual value to the high voltage generator for regulating the output thereof. The first circuit determines an actual value from a voltage divider connected to two high voltage generators in series. The other circuit includes radiation detectors, one of which may be filtered, which provide an indication of the radiation quality and are used to modulate an incoming actual value signal. Operation of the switching device is controlled by a ramp generator such that in the range of lower x-ray tube high voltages, which occur immediately after switching on the x-ray tube, control is undertaken on the basis of the actual value of the x-ray tube high voltage through the voltage divider, and upon the attainment of a higher x-ray tube high voltage a switch over occurs such that control of the high voltage is effected by the radiation-detecting circuit.

Abstract: A method of determining the optimum values of voltage and current for operation of an X-ray source by choosing a point of intersection at the lowest voltage value of a curve representing an operating range limitation function of the X-ray source with a curve representing a current-voltage function that passes through a desired operating current value that is determined by means of one or more exposure measurements.

Abstract: An X-ray system tester for measuring a set of electrical signals comprising anode voltage, cathode voltage, anode current, filament current and line voltage produced by an X-ray system during the operation of such system. A selector is provided, which couples one of the electrical signals of the sets thereof produced or one of a plurality of processing control signals entered by an operator from a control panel, to a digitizing section, selectively in accordance with control signals provided to the selector by a computing section. The digitizing section converts the selected signal whether produced by the X-ray system or entered from the control panel, into a train of pulses having a frequency proportional to the value of the selected signal. The pulses in the pulse train are counted by a counter. The number of counts being used by the computing section to determine the frequency, and hence, the value of the selected signal.

Abstract: The invention relates to the polarization of a cathode of an X-ray tube by a high voltage cable comprising less conductors than the tube has polarization terminals. The missing voltages are processed by a device according to the invention, which comprises a voltage divider positioned between two of the voltages applied to the input terminals. It permits the use of standard long high voltage cables with limited stray capacitance without inducing dimensional control losses with respect to the tube foci.Application to multifocus X-ray sources.

Abstract: An X-ray generator system having control circuitry disposed for applying a selected voltage between cathode and anode electrodes of an X-ray tube and for sending a selected current through the tube during an X-ray exposure, the control circuitry including a voltage indicator network disposed for subtracting from the selected voltage anticipated losses in accordance with the level of selected current to indicate prior to the initiation of the X-ray exposure the actual voltage that will be applied between the cathode and anode electrode during the X-ray exposure.

Abstract: In X-ray tubes comprising a metal grid, it may occur that the necessary emission current cannot be reached in unfavorable circumstances. This situation is improved by the invention in that the high voltage for the X-ray tube is derived from at least three series connected high voltage generators, the first and the second generator being connected to the anode and the cathode, respectively, of the X-ray tube while the third generator can be connected either to the anode side (in the case of high tube voltages) or to the cathode side (in the case of low tube voltage) by means of a switching device.

Abstract: The present invention relates to a radiation monitoring device which is utilized to measure the voltage supplied to an x-ray generator of an x-ray machine in terms of kVp units. The device includes a pair of detectors which are simultaneously exposed to an x-ray beam. The x-ray beam is filtered by a first amount before being supplied to the first detector, and is filtered by a second amount, greater than the first amount, before being supplied to the second detector. Both detectors generate an output signal having a magnitude proportional to the amount of radiation energy received. The ratio between the detector output signals is proportional to the amount of voltage supplied to the x-ray generator. The output signal of the first detector is an input to a first integrator which generates a voltage ramp output signal as an input to a trigger circuit. The output of the second detector is supplied to a second integrator which generates a second voltage ramp output signal as an input to a sample/hold circuit.

Abstract: An X-ray cine radiography apparatus comprising: an X-ray tube for radiating X-rays toward an object under examination; an image intensifier for converting the X-rays transmitted through the object into a visual image; a cine camera for picking up the visual image; a photomultiplier for detecting a brightness of the visual image to produce an electric signal; a first potentiometer for setting an upper limit tube voltage of said X-ray tube; a second potentiometer for detecting a signal corresponding to an actual tube voltage of said X-ray tube; a comparator for comparing the output signal of said second potentiometer with that of said first potentiometer and for producing an enabling signal when the former recited output signal exceeds the latter recited output signal; means for controlling quantity of light of the visual image picked up by said cine camera in accordance with the enabling signal of said comparator; and means for adjusting the actual tube voltage in response to the output signal of said controll