Hybridized semiconductor pixel detector arrays for use in digital radiography

• US 5,379,336 A
• Filed: 09/20/1993
• Issued: 01/03/1995
• Est. Priority Date: 05/21/1992
• Status: Expired due to Term

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Hughes Aircraft Company (Rtx Corporation)
• Inventors: Kramer, Gordon, Collins, Timothy C., Wolfe, Douglas W., Worley, Stuart
• Primary Examiner(s): Porta, David P.
• Application Number:
  US08/124,351
• Time in Patent Office: 470 Days
• Field of Search: 378/62, 378/51, 378/57, 378/58, 378/98, 378/99, 378/98.8, 378/98.12, 358/111, 250/320.09
• US Class Current: 378/98.8
• CPC Class Codes: G01T 1/2928 using solid state detectors
• CPC Class Codes: H04N 25/79 Arrangements of circuitry being divided between different or multiple substrates, chips or circuit boards, e.g. stacked image sensors

Abstract

A solid state x-ray detector which is a two-dimensional array of individual pixel elements is described. The hybrid semiconductor construction produces detector elements with high spatial resolution (<30 microns), high sensitivity to the entire x-ray spectrum, and frame rates greater than 1000 Hz. In a biomedical application these arrays provide high quality real time digital radiographic images that are directly coupled to an image processing system for image enhancement and computer aided diagnosis. In an alternative embodiment of the invention, the hybrid construction incorporated into an automated manufacturing process facilitates the real time, nondestructive, x-ray examination of manufactured objects during the production process. Structural defects in inorganic objects under test are identified in real time during the manufacturing process are corrected when feedback signals are generated from the electronic image data generated during the nondestructive test process.

Claims

1. An non-destructive test system, comprising:

at least one source for x-rays;

a hybrid semiconductor pixel array positioned to receive and convert x-ray photons from said source into electrical signals, wherein said pixel array is comprised of a plurality of detector pixels on a semiconductor substrate individually interconnected to a readout chip; and

a processor operable to receive and convert said electrical signals into an electronic image.

2. The non-destructive test system in claim 1 wherein said source for x-rays further comprises a high energy tube.

3. The non-destructive test system in claim 1 wherein said source for x-rays further comprises Cobalt 60.

4. The non-destructive test system in claim 1 wherein said source for x-rays further comprises a synchrotron.

5. The system of claim 1 wherein said detector array comprises silicon.

6. The system of claim 1 wherein said detector array comprises germanium.

7. The system of claim 1 wherein said detector array comprises cadmium telluride.

8. The system of claim 1 wherein said detector array comprises indium antimonide.

9. A method of providing a non-destructive test system, said method comprising the steps of:

providing at least one source for x-rays;

providing a subject under test exposed to said x-rays, said subject operable to selectively absorb said x-rays;

providing a hybrid semiconductor pixel array positioned proximate said subject under test operable to receive and convert unabsorbed x-ray photons passing through said subject under test into electrical signals, wherein said pixel array is comprised of a plurality of detector pixels on a semiconductor substrate individually interconnected to a readout chip; and

providing a processor operable to receive and convert said electrical signals into an electronic image.

10. A method of non-destructive testing, said method comprising the steps of:

generating x-rays from at least one source;

exposing a subject under test to said x-rays, said subject operable to selectively absorb said x-rays;

positioning a hybrid semiconductor pixel array proximate said subject under test, said hybrid semiconductor pixel array operable to receive and convert unabsorbed x-ray photons passing through said subject under test into electrical signals, wherein said pixel array is comprised of a plurality of detector pixels on a semiconductor substrate individually interconnected to a readout chip processing said electrical signals into an electronic image.

11. An automated non-destructive test system, used in a manufacturing process, comprising:

at least one source for x-rays;

an object under test exposed to said x-rays, said object operable to selectively absorb said x-rays;

a hybrid semiconductor pixel array positioned proximate said object under test operable to receive and convert unabsorbed x-ray photons passing through said object under test into electrical signals, wherein said pixel array is comprised of a plurality of detector pixels on a semiconductor substrate individually interconnected to a readout chip;

a processor operable to receive and convert said electrical signals into an electronic image; and

a comparator operable to compare said electronic image to a stored known image for said object, said comparator further operable to generate a feedback electrical signal into said manufacturing process.

12. The non-destructive test system in claim 11 wherein said source for x-rays further comprises a high energy tube.

13. The non-destructive test system in claim 11 wherein said source for x-rays further comprises Cobalt 60.

14. The non-destructive test system in claim 11 wherein said source for x-rays further comprises a synchrotron.

15. A method of providing an automated non-destructive test system to a manufacturing process, comprising:

providing at least one source for x-rays;

providing an object under test exposed to said x-rays, said object operable to selectively absorb said x-rays;

providing a hybrid semiconductor pixel array positioned proximate said object under test operable to receive and convert unabsorbed x-ray photons passing through said object under test into electrical signals, wherein said pixel array is comprised of a plurality of detector pixels on a semiconductor substrate individually interconnected to a readout chip;

providing a processor operable to receive and convert said electrical signals into an electronic image; and

providing a comparator operable to compare said electronic image to a stored known image for said object, said comparator further operable to generate a feedback electrical signal into said manufacturing process.

16. An automated method of non-destructive testing incorporated into a manufacturing process, said method comprising the steps of:

generating x-rays;

exposing a manufactured object under test to said x-rays, said object operable to selectively absorb said x-rays;

positioning a hybrid semiconductor pixel array proximate said object under test, said hybrid semiconductor pixel array operable to receive and convert unabsorbed x-ray photons passing through said object under test into electrical signals, wherein said pixel array is comprised of a plurality of detector pixels on a semiconductor substrate individually interconnected to a readout chip;

processing said electrical signals into an electronic image;

comparing said electronic image to a stored known image of said manufactured object; and

revising the manufacturing process in response to the comparison between said manufactured object under test and said stored known image of said manufactured object.

17. A non-destructive test system for biomedical applications, comprising:

at least one source for x-rays;

an organic subject under test exposed to said x-rays, said subject operable to selectively absorb said x-rays;

a hybrid semiconductor pixel array positioned proximate said subject under test operable to receive and conceal unabsorbed x-ray photons passing through said subject under test into electrical signals, wherein said pixel array is comprised of a plurality of detector pixels on a semiconductor substrate individually interconnected to a readout chip; and

a processor operable to receive and convert said electrical signals into an electronic image of said organic subject under test.

18. A method of providing a non-destructive test system for biomedical applications, comprising:

providing at least one source for x-rays;

providing an organic subject under test exposed to said x-rays, said subject operable to selectively absorb said x-rays;

providing a hybrid semiconductor pixel array positioned proximate said subject under test operable to receive and convert unabsorbed x-ray photons passing through said subject under test into electrical signals, wherein said pixel array is comprised of a plurality of detector pixels on a semiconductor substrate individually interconnected to a readout chip; and

providing a processor operable to receive and convert said electrical signals into an electronic image of said organic subject under test.

19. A manufacturing system incorporating a non-destructive test system, comprising:

a manufacturing line for producing an object, said object operable to selectively absorb x-rays;

a non-destructive test system disposed along said manufacturing line for evaluating said object, said test system comprising;

at least one source of x-rays positioned to expose said object to x-rays;

a hybrid semiconductor pixel array positioned proximate said object operable to receive and convert unabsorbed x-ray photons passing through said object into electrical signals, wherein said pixel array is comprised of a plurality of detector pixels on a semiconductor substrate individually interconnected to a readout chip;

a processor operable to receive and convert said electrical signals into an electronic image; and

a comparator operable to compare said electronic image to a stored known image for said object, said comparator further operable to generate a feedback electrical signal into said manufacturing system.