X-ray imager with CMOS sensor embedded in TFT flat panel

Patent metadata

Field	Value
Publication number	US-9588235-B2
Application number	US-201414229610-A
Country	US
Kind code	B2
Filing date	Mar 28, 2014
Priority date	Jun 27, 2013
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

An x-ray imaging device include a scintillator layer configured to generate light from x-rays, a TFT detector array at the first surface of the scintillator layer to detect light generated in the scintillator, and a CMOS sensor at the second surface of the scintillator layer to detect light generated in the scintillator.

First claim

The invention claimed is:

1. An x-ray imaging device, comprising:
a scintillator layer configured to generate light from x-rays, said scintillator layer comprises a first surface and a second surface;
a first detector at the first surface configured to detect light generated in the scintillator layer, said first detector comprises a plurality of first detection pixels configured to generate a first image with a first resolution; and
a second detector at the second surface configured to detect light generated in the scintillator layer, said second detector comprises a plurality of second detection pixels configured to generate a second image with a second resolution, wherein the second detection pixels are different from the first detection pixels, and the first resolution of the first image differs from the second resolution of the second image.

2. The x-ray imaging device of claim 1 wherein the first detector comprises a thin-film transistor (TFT) detector array comprising the plurality of first detection pixels having a first pixel size, and the second detector comprises a complementary metal-oxide-semiconductor (CMOS) sensor comprising the plurality of second detection pixels having a second pixel size smaller than the first pixel size.

3. The x-ray imaging device of claim 2 wherein the first pixel size is an integral multiple of the second pixel size.

4. The x-ray imaging device of claim 3 wherein the scintillator layer, the first detector, and the second detector are arranged in a configuration such that x-rays traverse the TFT detector array before propagating in the scintillator layer.

5. The x-ray imaging device of claim 4 wherein the first detector comprises a base plate and the TFT detector array, and the first detector is disposed such that the TFT detector array is in between the base plate and the scintillator layer.

6. The x-ray imaging device of claim 5 wherein the CMOS sensor comprises a wafer and the plurality of second detection pixels, and the CMOS sensor is disposed such that the plurality of second detection pixels are in between the scintillator layer and the wafer.

7. The x-ray imaging device of claim 6 further comprising a fiber optical faceplate (FOFP) disposed in between the scintillator layer and the CMOS sensor.

8. The x-ray imaging device of claim 6 wherein the wafer of the CMOS sensor has a through via near a periphery of the wafer to allow electrical coupling to the second detection pixels through the via.

9. The x-ray imaging device of claim 5 wherein the CMOS sensor comprises a wafer and the plurality of second detection pixels, and the CMOS sensor is disposed such that the wafer is in between the scintillator layer and the plurality of second detection pixels such that light detected by the second detection pixels passes through the wafer.

10. The x-ray imaging device of claim 3 wherein the scintillator layer, the first detector, and the second detector are arranged in a configuration such that x-rays traverse the CMOS sensor before propagating in the scintillator layer.

11. The x-ray imaging device of claim 10 wherein the first detector comprises a base plate and the TFT detector array, and the first detector is disposed such that TFT detector array is in between the scintillator layer and the base plate.

12. The x-ray imaging device of claim 11 wherein the CMOS sensor comprises a wafer and the plurality of second detection pixels, and the CMOS sensor is disposed such that the plurality of second detection pixels are in between the scintillator layer and the wafer.

13. The x-ray imaging device of claim 12 wherein the wafer of the CMOS sensor has a through via near a periphery of the wafer to allow electrical coupling to the second detection pixels through the via.

14. The x-ray imaging device of claim 12 further comprising an additional scintillator layer between the CMOS sensor and the scintillator layer, said additional scintillator layer is in contact with the scintillator layer, providing a space between the scintillator layer and a periphery of the second detector array to allow an electrical connector to couple with the second detector array.

15. The x-ray imaging device of claim 12 wherein the CMOS sensor comprises a wafer and the plurality of second detection pixels, and the CMOS sensor is disposed such that the wafer is in between the scintillator layer and the plurality of second detection pixels such that light detected by the second detection pixels passes through the wafer.

16. The x-ray imaging device of claim 10 further comprising a fiber optical faceplate (FOFP) disposed in between the scintillator layer and the CMOS sensor.

17. The x-ray imaging device of claim 16 wherein the CMOS sensor comprises a wafer and the plurality of second detection pixels, and the CMOS sensor is disposed such that the plurality of second detection pixels are in between the fiber optical faceplate and the wafer.

18. The x-ray imaging device of claim 3 wherein the first detector has a first active detection area defined by the plurality of the first detection pixels of the TFT detector array and the second detector has a second active detection area defined by the plurality of the second detection pixels of the CMOS sensor, said second active detection area is smaller than the first active detection area.

19. The x-ray imaging device of claim 18 wherein the first active detection area of the first detector covers substantially the entire first surface of the scintillator layer and the second active detection area of the second detector covers a portion of the second surface of the scintillator layer.

20. The x-ray imaging device of claim 19 wherein at least a portion of the second surface of the scintillator layer that is uncovered by the second active detection area is coated with a reflective coating.

21. The x-ray imaging device of claim 19 further comprising a detachable reflector covering at least a portion of the second surface that is uncovered by the second active area.

22. The x-ray imaging device of claim 19 wherein a portion of the second surface of the scintillator layer that is uncovered by the second active detection area is applied with an optical coating having a reflectivity substantially same as a reflectivity of the CMOS sensor.

23. The x-ray imaging device of claim 2 wherein the second detector comprises two or more CMOS sensors tiled side by side forming a rectangular or square active detection area.

24. The x-ray imaging device of claim 23 wherein said rectangular or square active detection area covers substantially an entire width or side of the second surface of the scintillator layer.

25. The x-ray imaging device of claim 1 wherein the first detection pixels having a first pixel size, and the second detection pixels having a second pixel size smaller than the first pixel size.

26. The x-ray imaging device of claim 1 wherein the first detector comprises a first TFT detector array and the second detector comprises a second TFT detector array.

27. The x-ray imaging device of claim 1 wherein the plurality of the first detection pixels define a first active detection area, and the plurality of the second detection pixels define a second active detection area smaller than the first active detection area.

28. The x-ray imaging device of claim 1 wherein the plurality of the first detection pixels have

Assignees

• Varian Med Sys Inc

Inventors

• Weisfield Richard
• Colbeth Richard
• Mollov Ivan
• Ganguly Arundhuti

Classifications

• G01T1/2018 Primary

  Scintillation-photodiode combinations · CPC title

• G01T1/20185 Primary

  Coupling means between the photodiode and the scintillator, e.g. optical couplings using adhesives with wavelength-shifting fibres · CPC title