JPH0440017B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a slip ring for use in a high voltage application path to an X-ray tube in an X-ray CT scanner.

[Technical background of the invention and its problems]

Conventionally, X-ray CT scanners have an X-ray tube mounted on a rotation frame that has a diameter larger than the diameter of the specimen insertion hole into which the specimen can be inserted.
In order to enable the rotation frame to rotate an arbitrary number of times, a slip ring is interposed between the X-ray tube and a high voltage generator installed outside the X-ray CT scanner. In this slip ring, a brush-like electrode for power supply connected to the high voltage generator is in contact with the outer or inner circumference of an annular rotating system, and the rotating part and the fixed part are electrically connected.

However, the rotation speed of the annular rotating system is at most 1 rotation/sec at most, but since the diameter of the rotating system is large, the amount of relative movement between the contact point with the brush-shaped electrode and the contacted point becomes large. brush wear,
There was a problem in that the brush-like electrodes were severely damaged and required frequent maintenance and inspection and replacement.

[Purpose of the invention]

The present invention was developed in view of the above circumstances, and provides a slip ring for an X-ray CT scanner that can reduce wear on the electrode portion of the slip ring and can perform continuous rotation at a desired rotation speed. The purpose is to

[Summary of the invention]

The outline of the present invention for achieving the above object includes a frame, an X
A rotating system that holds the ray tube and has a conductive part for applying high voltage to the X-ray tube, and is rotatable via an insulating bearing so as to rotate in contact with the conductive part of the rotating system. It is characterized by comprising an electrically conductive disk attached to the frame, and an electrode portion whose tip is in contact with the center of rotation of the disk.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to the drawings.

1 to 3 are schematic explanatory diagrams showing an X-ray CT scanner section incorporating the slip ring of the present invention. In each figure, reference numeral 1 denotes an annular rotating system supported by a frame (not shown) of the main body of the scanner. can be rotated as one unit. Three guide grooves 3 are provided along the circumferential direction on the outer peripheral surface of the annular rotating system 1.
a, 3b, and 3c are provided, each of which is made of a conductive material. Reference numerals 4a, 4b, and 4c are electrically conductive disk-shaped rotors rotatably attached to the fixed part of the scanner main body frame via insulating bearings 5 (see Fig. 5). 4a, 4b, 4c are the guide grooves 3a,
3b and 3c, and are guided by the guide grooves to rotate in accordance with the rotation of the rotation system 1. Reference numerals 6a, 6b, and 6c are rod-shaped electrodes whose tips are in contact with the rotation center point C of each rotor 4a, 4b, and 4c. The electrode 6a is a high voltage generator (not shown) installed outside the scanner body.
The electrode 6b is connected to a high voltage cable pulled out from the positive side of the high voltage generator, and the electrode 6b is similarly connected to a high voltage cable pulled out from the negative side of the high voltage generator.
Both electrodes 6a and 6b are used for power supply. On the other hand, the electrode 6c is a grounding electrode whose end is grounded. 7 is arranged so as to be swingable in the body axis direction of the subject so that it is always located on the straight line extension connecting the X-ray focal point of the X-ray tube 2 and the rotation center point A of the rotation system 1, as shown in FIG. The detector is

When the slip ring is configured as described above, the high voltage power output from the high voltage generator reaches the supply electrodes 6a and 6b from the high voltage cable, and then reaches the conductive layer of the rotating system 1 via the rotors 4a and 4b. The supplied high voltage power is applied between the cathode and anode of the X-ray tube 2. At this time, the high voltage power is supplied as the rotating system 1 and the rotors 4a and 4b rotate, and the electrodes 6a and 6b that supply the power from the outside are as shown in FIGS. 4 and 5. The part that is in contact with the center of rotation C of the disc-shaped rotors 4a, 4b and where friction is generated by the rotation of the rotor is the center of rotation C and the rod electrodes 6a, 6b.
Since there is no relative movement between the two and the movement is small, the electrodes 6a, 6
b. Friction and damage can be minimized. Similarly, since the grounding electrode 6c is also in contact with the rotational center point C of the rotor 4c, there is less friction and damage to the electrode 6c. Therefore, the slip ring of the present invention can be
By using it in a CT scanner, the X-ray tube 2 can be continuously rotated at a desired rotation speed. For example, the X-ray CT scanner can eliminate dead time when performing a cardiac scan of the heart, and can be used to perform a dynamic scan of the liver, brain, etc. can eliminate the dead time for rapid changes in CT values after contrast medium injection, and can improve clinical effectiveness. In addition to the scan described above, a helical scan can also be performed.

Furthermore, the rotor is used to supply power to the rotating system, and the configuration that rotatably supports the rotor and the configuration that supplies power are separated, so that each of the pressure support and power supply to the rotor rotation system is separated. Functions can be set optimally.

One embodiment of the present invention has been described in detail above, but
The present invention is not limited to the above embodiments,
It goes without saying that the present invention can be modified and implemented as appropriate within the scope of the gist of the present invention.

〔Effect of the invention〕

As detailed above, according to the present invention, the slip ring is configured to minimize wear and damage to the electrodes that supply power from the outside, so there is no need to frequently maintain, inspect, or replace the electrodes. It is possible to provide a slip ring for an X-ray CT scanner that can smoothly and reliably rotate the X-ray tube continuously at a desired rotation speed.

[Brief explanation of drawings]

1 to 3 are schematic explanatory diagrams showing a scanner section incorporating the slip ring of the present invention into an X-ray CT apparatus, of which FIG. 1 is a front view, FIG. 2 is a plan view, and FIG. Each shows a cross-sectional view. FIGS. 4 and 5 are schematic explanatory diagrams showing the basic principle of the present invention, and show the relationship between the rotating system, the rotor, and the electrodes. 1...Rotating system, 2...X-ray tube, 4a, 4b, 4
c...rotor, 6a, 6b, 6c...electrode.

Claims (1)

[Claims] 1 a frame, a rotating system that is rotatably supported by the frame and has a conductive part for holding an X-ray tube and applying a high voltage to the X-ray tube; and a rotating system that is in contact with the conductive part of the rotating system. For an X-ray CT scanner, comprising: a conductive disk rotatably attached to the frame via an insulating bearing; and an electrode portion whose tip is in contact with the center of rotation of the disk. slip spring.