Tomographic apparatus and method of obtaining an arbitrary cross-sectional image

• US 5,978,440 A
• Filed: 11/25/1997
• Issued: 11/02/1999
• Est. Priority Date: 11/28/1996
• Status: Expired due to Fees

• Current Assignee: Korea Electronics Technology Institute (Government of South Korea)
• Original Assignee: korea institute of industrial technology
• Inventors: Kang, Sung Taek, Jeong, Jae Hoon
• Primary Examiner(s): Porta, David P.
• Application Number:
  US08/977,946
• Time in Patent Office: 707 Days
• Field of Search: 378/21-27, 378/98.8
• US Class Current: 378/21
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]

Abstract

A tomographic apparatus for obtaining a cross-sectional image by fixing an X-ray source, and synchronously rotating an object under examination and a detector. According to the apparatus, the slope angle of the X-ray source can be sufficiently enlarged by the adjustment of the X-ray tube, and thus the precision of the obtained cross-sectional image can be heightened. Also, a method of obtaining a cross-sectional image of a three-dimensional object from an arbitrary direction and height.

Claims

1. A tomographic apparatus for obtaining a cross-sectional image, comprising:

a fixed X-ray source;

a rotating table on which an object is laid for projecting an X-ray beam generated from said fixed X-ray source directly onto said object;

said rotating table being adjustable in angle with respect to the horizontal between 0° and

60°

;

an image amplifying tube for converting the X-ray beam passing through the object into a visible light image;

a detector for detecting the visible light image to output an analog image signal;

a frame grabber for storing and converting the analog image signal into a digital image signal;

an image processing section for processing the digital image signal outputted from the frame grabber taking into account the angle between the table and the horizontal;

a system control section for controlling the fixed X-ray source and outputting a control signal according to the digital image signal processed by the image processing section;

a motor control section for synchronously rotating the object and the detector according to the control signal from the system control section; and

an output section for outputting the image signal processed by the image processing section.

2. The apparatus as claimed in claim 1, wherein said detector includes a noise filter, connected thereto, for removing noise of said analog image signal.

3. The apparatus as claimed in claim 1, wherein said detector comprises a charge coupled device and a Slip-Ring.

4. A method of obtaining a cross-sectional image, comprising the steps of:

aligning a fixed X-ray source and a rotating center of a table defining an image plane of an object on said table with a center of a rotating detector;

projecting a beam from said X-ray source directly onto said object;

providing adjustment of said table with respect to the horizontal to enable said table to assume an angle of up to 60°

with respect to the horizontal;

acquiring a plurality of images of the object by synchronously rotating the object and the detector;

correcting distortions of the acquired images; and

obtaining a cross-sectional image by synthesizing the corrected images.

5. The method as claimed in claim 4, wherein said step of obtaining the cross-sectional image comprises the substeps of:

synthesizing the images of the object acquired from arbitrary directions and

synthesizing the images of the object acquired from arbitrary heights.