Semiconductor X-ray Detector

Patent metadata

Field	Value
Publication number	US-2018017685-A1
Application number	US-201515122449-A
Country	US
Kind code	A1
Filing date	Apr 7, 2015
Priority date	Apr 7, 2015
Publication date	Jan 18, 2018
Grant date	—

Abstract

An apparatus for detecting X-ray, comprising: an X-ray absorption layer comprising an electrode; a first voltage comparator configured to compare a voltage of an electrode to a first threshold; a second voltage comparator configured to compare the voltage to a second threshold; a counter configured to register a number of X-ray photons absorbed by the X-ray absorption layer; a controller; the controller is configured to start a time delay from a time at which the first voltage comparator determines that an absolute value of the voltage equals or exceeds an absolute value of the first threshold; the controller is configured to activate the second voltage comparator during the time delay; the controller is configured to cause the number registered by the counter to increase by one, if, during the time delay, the second voltage comparator determines that an absolute value of the voltage equals or exceeds an absolute value of the second threshold.

First claim

What is claimed is:

1 . An apparatus suitable for detecting x-ray, comprising:
an X-ray absorption layer comprising an electrode; a first voltage comparator configured to compare a voltage of the electrode to a first threshold; a second voltage comparator configured to compare the voltage to a second threshold; a counter configured to register a number of X-ray photons absorbed by the X-ray absorption layer; a controller; wherein the controller is configured to start a time delay from a time at which the first voltage comparator determines that an absolute value of the voltage equals or exceeds an absolute value of the first threshold; wherein the controller is configured to activate the second voltage comparator during the time delay; wherein the controller is configured to cause the number registered by the counter to increase by one, if the second voltage comparator determines that an absolute value of the voltage equals or exceeds an absolute value of the second threshold.

2 . The apparatus of claim 1 , further comprising a capacitor module electrically connected to the electrode, wherein the capacitor module is configured to collect charge carriers from the electrode.

3 . The apparatus of claim 1 , wherein the controller is configured to activate the second voltage comparator at a beginning or expiration of the time delay.

4 . The apparatus of claim 1 , further comprising a voltmeter, wherein the controller is configured to cause the voltmeter to measure the voltage upon expiration of the time delay.

5 . The apparatus of claim 4 , wherein the controller is configured to determine an X-ray photon energy based on a value of the voltage measured upon expiration of the time delay.

6 . The apparatus of claim 1 , wherein the controller is configured to connect the electrode to an electrical ground.

7 . The apparatus of claim 1 , wherein a rate of change of the voltage is substantially zero at expiration of the time delay.

8 . The apparatus of claim 1 , wherein a rate of change of the voltage is substantially non-zero at expiration of the time delay.

9 . The apparatus of claim 1 , wherein the X-ray absorption layer comprises a diode.

10 . The apparatus of claim 1 , wherein the X-ray absorption layer comprises silicon, germanium, GaAs, CdTe, CdZnTe, or a combination thereof.

11 . The apparatus of claim 1 , wherein the apparatus does not comprise a scintillator.

12 . The apparatus of claim 1 , wherein the apparatus comprises an array of pixels.

13 . A system comprising the apparatus of claim 1 and an X-ray source, wherein the system is configured to perform X-ray radiography on human chest or abdomen.

14 . A system comprising the apparatus of claim 1 and an X-ray source, wherein the system is configured to perform X-ray radiography on human mouth.

15 . A cargo scanning or non-intrusive inspection (NII) system, comprising the apparatus of claim 1 and an X-ray source, wherein the cargo scanning or non-intrusive inspection (NII) system is configured to form an image using backscattered X-ray.

16 . A cargo scanning or non-intrusive inspection (NII) system, comprising the apparatus of claim 1 and an X-ray source, wherein the cargo scanning or non-intrusive inspection (NII) system is configured to form an image using X-ray transmitted through an object inspected.

17 . A full-body scanner system comprising the apparatus of claim 1 and an X-ray source.

18 . An X-ray computed tomography (X-ray CT) system comprising the apparatus of claim 1 and an X-ray source.

19 . An electron microscope comprising the apparatus of claim 1 , an electron source and an electronic optical system.

20 . A system comprising the apparatus of claim 1 , wherein the system is an X-ray telescope, or an X-ray microscopy, or wherein the system is configured to perform mammography, industrial defect detection, microradiography, casting inspection, weld inspection, or digital subtraction angiography.

21 . A method comprising:
starting a time delay from a time at which an absolute value of a voltage of an electrode of an X-ray absorption layer equals or exceeds an absolute value of a first threshold; activating a second circuit during the time delay; if an absolute value of the voltage equals or exceeds an absolute value of a second threshold, increasing a count of X-ray photon incident on the X-ray absorption layer by one.

22 . The method of claim 21 , further comprising connecting the electrode to an electrical ground.

23 . The method of claim 21 , further comprising measuring the voltage upon expiration of the time delay.

24 . The method of claim 21 , further comprising determining an X-ray photon energy based on a value of the voltage at expiration of the time delay.

25 . The method of claim 21 , wherein a rate of change of the voltage is substantially zero at expiration of the time delay.

26 . The method of claim 21 , wherein a rate of change of the voltage is substantially non-zero at expiration of the time delay.

27 . The method of claim 21 , wherein activating the second circuit is at a beginning or expiration of the time delay.

28 . The method of claim 21 , wherein the second circuit is configured to compare the absolute value of the voltage to the absolute value of the second threshold.

29 . The method of claim 21 , further comprising deactivating a first circuit at a beginning of or during the time delay.

30 . The method of claim 29 , wherein the first circuit is configured to compare the absolute value of the voltage to the absolute value of the first threshold.

31 . The method of claim 21 , further comprising deactivating the second circuit at an expiration of the time delay or at a time when the absolute value of the voltage equals or exceeds the absolute value of the second threshold.

32 . A system suitable for phase-contrast X-ray imaging (PCI), the system comprising:
the apparatus of claim 1 , a second X-ray detector, a spacer, wherein the apparatus and the second X-ray detector are spaced apart by the spacer.

33 . The system of claim 32 , wherein the apparatus and the second X-ray detector are configured to respectively capture an image of an object simultaneously.

34 . The system of claim 32 , wherein the second X-ray detector is identical to the apparatus.

35 . A system suitable for phase-contrast X-ray imaging (PCI), the system comprising:
the apparatus of claim 1 , wherein the apparatus is configured to move to and capture images of an object exposed to incident X-ray at different distances from the object.

36 . The apparatus of claim 1 , wherein the controller is configured to deactivate the first voltage comparator at a beginning of the time delay.

37 . The apparatus of claim 1 , wherein the controller is configured to deactivate the second voltage comparator at expiration of the time delay or at a time when the second voltage comparator determines that the absolute value of the voltage equals or exceeds the absolute value of the second threshold, or a time in between.

Assignees

• Shenzhen Xpectvision Tech Co Ltd

Inventors

• Cao Peiyan

Classifications

• G01N23/041

  Phase-contrast imaging, e.g. using grating interferometers · CPC title

• G01N23/04

  and forming images of the material · CPC title

• G01T1/17 Primary

  Circuit arrangements not adapted to a particular type of detector {(pulse-selection circuits H03K, G01R)} · CPC title

• A61B6/4233 Primary

  using matrix detectors · CPC title

• G01T1/2928

  using solid state detectors · CPC title