Hitachi Medical Corporation

Hiroshi Takano

Takuya Domoto

Jun Takahashi

Akira Kurome

Tsutomu Suzuki

Takaaki Kobiki

Eiichi Makino

Hiroyuki Takeuchi

Takanobu Hatakeyama

Keiichi Chabata

Kazuhiko Sakamoto

In an X-ray generating device of the neutral grounding system, to remove an unbalance voltage generated due to difference in impedance of parallel transformer coils of the high voltage transformer and particularly an unbalance voltage involved with difference in impedance above and below the neutral points generated in a metal X-ray tube, a plurality of currents flowing in opposite directions through primary windings of the parallel transformer coils in the high voltage transformer are passed through by or wound around a common toroidal coil or wound around an outer circumference of the toroidal coil at a predetermined ratio of winding number, and the unbalance voltage occurring to the secondary side is cancelled by changing primary current with magnetic behavior.

X-ray generator and X-ray CT apparatus comprising same

A semiconductor switchconnected in series with a smoothing capacitoris constituted by connecting in parallel a diodeD which permits to flow current regenerated from energy of electric charges stored in a high voltage capacitorto a primary side of a high voltage transformerfor the smoothing capacitorand switching meansS which interrupts an output from the smoothing capacitor, and after turning off the switching meansS, through alternative on and off control of switching meansS&#x2dc;S the energy of electric charges stored in the high voltage capacitoris regenerated to the smoothing capacitorby making use of parasitic leakage inductanceL. As a result, an X-ray high voltage device is provided which permits to drop a wave tail of a tube voltage in a high speed without complexing the structure of the high voltage part thereof.

X-ray high voltage device

Between terminals of secondary windings in a high-voltage transformer (), there are connected in parallel input side terminals of a plurality of diode full bridge circuits each via voltage maintaining means such as a capacitor maintaining a voltage peak value for a longer period than the cycle of an inverter (). Between the input side terminals of the diode full bridge circuits, there are connected voltage maintaining means such as capacitors maintaining a voltage peak value for a longer period than the cycle of the inverter. Moreover, the output side terminals of the diode full bridges are connected in series via smoothing means such as almost equivalent smoothing capacitors and between the output side terminals, an anode grounding type X-ray tube () is connected. Thus, it is possible to realize a small-size and light-weight device at a reduced cost and reduce the ripple in the output voltage while using the anode grounding type X-ray tube.

X-ray generator with voltage doubler

An X-ray tube apparatus () having an anode rotating mechanism for preventing damage of the anode () of the X-ray tube apparatus thereby to shorten the X-ray exposure waiting time. When the measured number of revolutions of a rotary anode is determined to be predetermined number from only the impedance or current information on the basis of both voltage information and current information on a stator coil () of motor constituent elements for rotating the rotary anode, a DC high voltage outputted from an X-ray high-voltage unit () is applied between the anode () and a cathode () of the X-ray tube apparatus, thus exposing a subject () to X-rays and imaging the subject. An X-ray generating device and a radiograph are also disclosed.

X-ray apparatus with anode rotation number detecting means

An X-ray CT scanner having an X-ray tube for radiating X-rays to a subject, an X-ray detector for detecting X-rays that have penetrated the subject, a circular plate-like rotary member with an opening for insertion of a subject and having the X-ray tube and the X-ray detector mounted thereon at opposing positions with respect to the opening, a support for rotatably supporting the rotary member, and a rotary drive for rotating the rotary member around the subject. The X-ray tube and the X-ray detector are mounted on a side surface of the rotary member, the side surface being a unit mounting surface for mounting a control unit relating to at least one of generation and detection of the X-rays.

X-ray CT scanner

The rotary member carrying the X-ray radiation unfit and the X-ray detection unit and rotated around a subject is used as the rotor. The rotor is provided with a rotor core and a plurality of conductors connected to the core. The stator has at least one set of stator core and stator winding, the at least one set of stator core and stator winding being adapted to clamp the rotor and arranged at opposing positions. A three-phase AC current is supplied to the stator winding to generate a rotating magnetic field to rotate the rotor and thereby rotate the rotary member at high speed. Because the scan time can be reduced, the X-ray CT scanner can scan such moving organs as heart.

A power source apparatus distributes a current command value to be supplied to a load to a plurality of output current amplifiers connected in parallel with the load, and each of the output current amplifiers supplies an output current corresponding to the current command value so distributed. This power source apparatus prevents a circulating current between the output current amplifiers by controlling each output current amplifier so that the difference between the output current from each output current amplifier and the distributed current command value becomes zero, or by inserting current limiting devices into the output line of each output current amplifier.

Growing community of inventors

Moriya, Japan

Hiroshi Takano