Luggage inspection device

• US 5,247,561 A
• Filed: 01/02/1991
• Issued: 09/21/1993
• Est. Priority Date: 01/02/1991
• Status: Expired due to Term

• Current Assignee: Andreas F. Kotowski
• Original Assignee: Andreas F. Kotowski
• Inventors: Kotowski, Andreas F.
• Primary Examiner(s): Porta, David P.
• Application Number:
  US07/636,626
• Time in Patent Office: 993 Days
• Field of Search: 378/4, 378/6, 378/7, 378/19, 378/86-90, 378/901, 378/57
• US Class Current: 378/87
• CPC Class Codes: G01V 5/222 measuring scattered radiation
• CPC Class Codes: G01V 5/226 using tomography

Abstract

The invention provides an inspection system for closed containers, such as luggage, which applies radiant energy, such as x-rays, to a container and receives energy which is scattered, such as by Compton scattering, by objects in the container. The received energy is measured and a three-dimensional image of the objects in the container is constructed. The container may be moved relative to a fan-shaped primary x-ray beam, which illuminates a single slice of the container at a time. For example, the container may be moved by a conveyer belt, or, the container may be held stationary while the x-ray tube may comprise a steerable beam. A plurality of collimated x-ray sensors may receive energy which is scattered, at a fixed angle for each sensor, and transmits those measurements to a processor which reconstructs the three-dimensional image and displays that image for an operator. The processor may also search for, and raise an alarm if it detects, a sufficient volume of material with a mass density indicative of an explosive.

Claims

1. A device for inspecting a closed container, comprising

means for applying radiant energy to a plurality of volume elements inside said closed container;

a plurality of detectors, each associated with one of said plurality of volume elements, for receiving scattered energy therefrom, and for generating at least one measurement thereof; and

means for processing said measurements and for generating a three-dimensional image of said volume elements.

2. A device as in claim 1, wherein said radiant energy comprises x-ray energy.

3. A device as in claim 1, wherein said radiant energy comprises electromagnetic energy including photons with energy between about 150 Kev and about 4 Mev.

4. A device as in claim 1, wherein said means for applying comprises a fan-shaped x-ray beam.

5. A device as in claim 1, wherein said scattered energy comprises energy scattered by Compton scattering.

6. A device as in claim 1, wherein said means for receiving comprises at least one collimated x-ray sensor.

7. A device as in claim 1, wherein said means for receiving comprises a plurality of sensors, each for sensing scattered energy from a separate volume of said container.

8. A device as in claim 1, comprising means for receiving transmitted energy from said closed container.

9. A device as in claim 1, wherein said means for applying radiant energy comprises a fan-shaped x-ray beam, whereby said plurality of volume elements lie in a plane;

and wherein said plurality of detectors are disposed substantially parallel and at a predetermined angle from said plane, whereby said plurality of detectors generate a measure of scattered energy after incident beam attenuation and scattered beam attenuation.

10. A device as in claim 1, wherein said means for processing comprises means for correcting for incident beam attenuation and scattered beam attenuation.

11. A device for inspecting a closed container, comprising

means for applying radiant energy to a plurality of volume elements deep inside said closed container;

a plurality of detectors, each receiving scattered energy from one of said plurality of volume elements, for generating a measure of scattered energy after incident beam attenuation and scattered beam attenuation; and

means for processing said measurements, for correcting for incident beam attenuation and scattered beam attenuation, and for generating a measure of density for each one of said volume elements.

12. A device for inspecting a closed container which is moving in a predetermined direction, comprising

a fan-shaped radiant energy beam disposed at a first angle to said predetermined direction;

a plurality of detectors, each disposed to receive energy scattered after incident beam attenuation and scattered beam attenuation, at a predetermined second angle to said predetermined direction, from a volume element deep inside said closed container; and

means for processing said scattered energy, for correcting for said incident beam attenuation and scattered beam attenuation, and for generating a three-dimensional image of said volume.

13. A device for inspecting a closed container, comprising

a conveyer belt;

a fan-shaped x-ray beam disposed perpendicular to a direction of travel of said conveyor belt and disposed to illuminate a plurality of volume elements inside said container;

a plurality of collimated x-ray sensors, each disposed to receive x-rays scattered from one of said plurality of volume elements at a predetermined angle; and

a processor coupled to said plurality of collimated x-ray sensors.

14. A method of inspecting a closed container, comprising the steps of

applying radiant energy to a plurality of volume elements inside said closed container;

for each one of said plurality of volume elements, receiving scattered energy therefrom and generating at least one measurement thereof; and

processing said measurements and generating a three-dimensional image of said volume.

15. A method as in claim 14, wherein said radiant energy comprises x-ray energy.

16. A method as in claim 14, wherein said radiant energy comprises electromagnetic energy including photons with energy between about 150 Kev and about 4 Mev.

17. A method as in claim 14, wherein said scattered energy comprises energy scattered by Compton scattering.

18. A method as in claim 14, comprising the step of receiving transmitted energy from said closed container.

19. A device for inspecting a closed container, comprising

means for supporting said closed container and for moving said closed container substantially in a predetermined direction;

a radiant energy beam disposed at a first angle to said predetermined direction;

a plurality of sensors disposed to receive energy scattered from a plurality of volume elements inside said closed container at a plurality of differing second angles to said predetermined direction, each sensor being associated with one of said plurality of volume elements; and

means for processing said scattered energy and for generating a three-dimensional image of said volume elements.

20. A device as in claim 19, wherein said means for supporting and for moving comprises a conveyor belt.

21. A device as in claim 19, wherein said first angle is a predetermined angle.

22. A device as in claim 19, wherein said first angle is about a right angle.