High resolution detector for X-ray imaging

• US 20030010923A1
• Filed: 05/07/2002
• Published: 01/16/2003
• Est. Priority Date: 07/16/2001
• Status: Active Grant

• Current Assignee: Claymount Israel, Ltd.
• Original Assignee: Edge Medical Devices Ltd. (Varex Imaging Corporation)
• Inventors: Zur, Albert
• Granted Patent: US 6,784,433 B2
• Time in Patent Office: Days
• US Class Current: 250/370.09
• CPC Class Codes: G01T 1/247 Detector read-out circuitry for processing gain or off-set correction H04N
• CPC Class Codes: H04N 5/32 Transforming X-rays cameras or camera modules for generating image signals from X-rays H04N23/30; circuitry of SSIS for transforming X-rays into image signals H04N25/30

Abstract

An ionizing radiation image sensor and a method for ionizing radiation imaging, including an ionizing radiation sensitive element, a generally pixellated array of capacitors cooperating with the ionizing radiation sensitive element and a charge source, which is operative to electrically charge the pixellated array of capacitors through a gap.

Claims

1. An ionizing radiation image sensor including:

an ionizing radiation sensitive element;

a generally pixellated array of capacitors cooperating with said ionizing radiation sensitive element; and

a charge source which is operative to electrically charge the pixellated array of capacitors through a gap.

2. An ionizing radiation image sensor according to claim 1 and wherein each capacitor of said generally pixellated array includes an electrode having at least one conducting plate which is at least partially exposed for charge injection thereto.

3. An ionizing radiation image sensor including:

an ionizing radiation conversion multilayer element which is operative to convert impinging ionizing radiation to electrical charge;

an external charge source which is operative to emit electrical charge; and

an array of storage capacitors disposed between said ionizing radiation conversion multilayer element and said external charge source, said storage capacitors being operative to sink charge to or source charge from said ionizing radiation conversion multilayer element and to sink charge to or source charge from said external charge source.

4. An ionizing radiation image sensor according to claim 3 and wherein said ionizing radiation conversion multilayer element is sensitive to X-ray.

5. An ionizing radiation image sensor according to claim 3 and wherein said ionizing radiation conversion multilayer element includes at least one layer which directly converts X-ray radiation to electrical charge.

6. An ionizing radiation image sensor according to claim 5 and wherein said at least one layer which directly converts X-ray radiation to electrical charge is formed from amorphous selenium doped with at least one of arsenic and chlorine.

7. An ionizing radiation image sensor according to claim 3 and wherein said ionizing radiation conversion multilayer element includes at least one layer which converts X-ray radiation to optical radiation.

8. An ionizing radiation image sensor according to claim 7 and wherein said at least one layer which converts X-ray radiation to optical radiation is formed from one of the following materials:

cesium iodide doped with thallium and cesium iodide doped with sodium.

9. An ionizing radiation image readout device including:

an ionizing radiation sensitive element operative to convert impinging X-ray radiation to an electrical charge image; and

a storage capacitor array operative to store said electrical charge image and including;

a matrix array of plate electrodes; and

a linear array of elongate electrodes,

wherein the storage capacitor array is addressed via said plate electrodes and a charge image readout is carried out via said elongate electrodes.

10. An ionizing radiation image readout device according to claim 9 and further including at least one charge source which addresses said storage capacitor array by charge injection in a row-by-row manner.

11. An ionizing radiation image readout device according to claim 10 wherein said row-by-row charge injection results in generally uniform charging of said matrix array of plate electrodes.

13. An ionizing radiation imager according to claim 12 wherein the first resolution is a generally high resolution and wherein the second resolution is a generally lower resolution:

14. An ionizing radiation imager according to claim 12 wherein said integrated radiation data readout electronics provides data representing an X-ray image and wherein said real-time radiation data provides feedback for automatic exposure control.

16. A method according to claim 15 and wherein said charging comprises charge injection to each capacitor of said array via at least one conducting plate which is at least partially exposed for charge injection thereto.

18. A method according to claim 17 and wherein said ionizing radiation conversion multilayer element is sensitive to X-ray.

19. A method according to claim 17 and wherein said ionizing radiation conversion multilayer element includes at least one layer which directly converts X-ray radiation to electrical charge.

20. A method according to claim 17 and wherein said ionizing radiation conversion multilayer element includes at least one layer which converts X-ray radiation to optical radiation.

12. An ionizing radiation imager including:

a first array of storage capacitors which is operative to store a charge pattern representing an ionizing radiation image at a first resolution;

a second array of storage capacitors, capacitively coupled to said first array of storage capacitors, which is operative to store a charge pattern representing said ionizing radiation image at a second resolution;

integrated radiation data readout electronics connected to said first array of storage capacitors; and

real-time radiation data readout electronics connected to said second array of storage capacitors.

15. A method for ionizing radiation imaging and including:

providing an ionizing radiation sensitive element including an array of storage capacitors coupled thereto;

charging said array of storage capacitors to a generally uniform voltage level using a non-contact proximity charge source;

exposing said ionizing radiation sensitive element to impinging ionizing radiation causing imagewise discharge of said charged array of storage capacitors thus creating an electrical charge pattern therein corresponding to an ionizing radiation image; and

charging said array of storage capacitors to a generally uniform voltage level using a non-contact proximity charge source thereby causing readout of said an electrical charge pattern.

17. A method for ionizing radiation imaging including:

providing an ionizing radiation conversion multilayer element which is operative to convert impinging ionizing radiation to electrical charge;

causing an external charge source to emit electrical charge; and

causing an array of storage capacitors disposed between said ionizing radiation conversion multilayer element and said external charge source to sink charge to or source charge from said ionizing radiation conversion multilayer element and to sink charge to or source charge from said external charge source.

21. An ionizing radiation image readout method comprising:

causing an ionizing radiation sensitive element to convert impinging X-ray radiation to an electrical charge image; and

storing said electrical charge image on a storage capacitor array including a matrix array of plate electrodes and a linear array of elongate electrodes;

addressing said storage capacitor array via said plate electrodes; and

reading out said electrical charge image via said elongate electrodes.

22. A method for ionizing radiation imaging comprising:

causing a first array of storage capacitors to store a charge pattern representing an ionizing radiation image at a first resolution;

causing a second array of storage capacitors, capacitively coupled to said first array of storage capacitors, to store a charge pattern representing said ionizing radiation image at a second resolution;

reading out real-time radiation image data from said second array of storage capacitors; and

reading out integrated radiation image data from said first array of storage capacitors.

23. A method according to claim 22 and also comprising effecting real-time exposure control employing said real-time radiation image data.