Ultrahigh speed X-ray CT scanner

• US 4,866,745 A
• Filed: 03/30/1987
• Issued: 09/12/1989
• Est. Priority Date: 07/16/1986
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Square Enix
• Original Assignee: Kabushiki Kaisha Square Enix
• Inventors: Akai, Makoto
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Hynds, Joseph A.
• Application Number:
  US07/031,666
• Time in Patent Office: 897 Days
• Field of Search: 378/4, 378/9, 378/10, 378/16, 378/137
• US Class Current: 378/9
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/4028 resulting in acquisition of views from substantially different positions, e.g. EBCT
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]
• CPC Class Codes: H01J 35/04 Electrodes ; Mutual position thereof; Constructional adaptations therefor
• CPC Class Codes: H05G 1/70 Circuit arrangements for X-ray tubes with more than one anode; Circuit arrangements for apparatus comprising more than one X ray tube or more than one cathode H05G1/58 takes precedence

Abstract

An X-ray CT scanner comprises a plurality of X-ray generators which are arranged radially on a circle concentric with an object for measurement and each consists of a cathode electrode, an anode electrode constituting a target and a grid between the cathode and anode electrodes. For X-ray tomography, X-rays are projected onto the objects from the circle concentric therewith by sequentially temporarily removing a bias voltage applied to the grids of the respective X-ray generators for suppressing an electron beam directed from the cathode electrode to the anode electrode of each X-ray generator.

Claims

1. An ultrahigh-speed X-ray CT scanner comprising:

a substantially semicircular vacuum vessel disposed on a circumference of a circle concentrically surrounding a position for an object for measurement;

a plurality of X-ray generators disposed in said vacuum vessel and arranged on the circumference of the circle for projecting X-rays onto said object, each of said X-ray generators including a cathode electrode, a grid, a multi-stage electrode for converging and accelerating an electron beam emitted from said cathode electrode, and an anode electrode constituting a target;

means for applying a bias voltage to the grids,

means for temporarily removing the bias voltage applied to said grids one after another; and

a plurality of X-ray sensors supported by a substantially semicircular support which is disposed on the circumference of the circle at a position where said object intervenes between said sensors and said vacuum vessel, and arranged on the circumference of the circle for receiving the X-rays projected from said X-ray generators wherein each of said x-ray generators includes a beam deflection lens disposed between said multi-stage electrode and said target so as to deflect the electron beam in the axial direction of the object.

2. The X-ray CT scanner according to claim 1, wherein said target is formed of a film having a thickness equal to or less than the range of the electron beam accelerated.