Radiation imaging apparatus and radiation imaging system

Patent metadata

Field	Value
Publication number	US-9726767-B2
Application number	US-201514810579-A
Country	US
Kind code	B2
Filing date	Jul 28, 2015
Priority date	Aug 6, 2014
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

A radiation imaging apparatus includes a unit constituted by arranging blocks in line and an information processing unit. Each of the blocks includes a conversion element configured to generate an image signal corresponding to radiation, a switching element connected between the conversion element and a column signal line, a detection element configured to detect radiation, and a detection signal line connected to the detection element. The information processing unit corrects a signal from the detection element, by using a value of the signal based on a parasitic capacitance between the conversion elements arranged on the same column as a column of the detection element.

First claim

What is claimed is:

1. A radiation imaging apparatus comprising:
a conversion element configured to generate an image signal corresponding to radiation
a detection element configured to detect radiation;
a detection signal line connected to the detection element; and
a processing unit,
wherein the processing unit performs calculation of a signal from the detection element, during a period in which exposure of radiation is being performed, for at least one of detecting a start of irradiation of radiation and measuring amount of irradiation, and
the calculation is performed based on a signal provided from the detection signal line, a capacitance of the conversion element, a parasitic capacitance between the conversion element and the detection signal line, and a capacitance of the detection element.

2. The apparatus according to claim 1 , wherein the calculation is performed based on a value of a capacitance of the conversion element, a value of a capacitance of the detection element, a value of the parasitic capacitance, the number of detection elements connected to the detection signal line, and the number of conversion elements which generate the parasitic capacitance between the conversion element and the detection signal line.

3. The apparatus according to claim 1 , further comprising a switching element connected between the conversion element and a column signal line, wherein the column signal line also operates as the detection signal line.

4. The apparatus according to claim 1 , wherein a unit is constituted by arranging blocks which include the conversion element and a detection signal line in line along the detection signal line, and a signal from the detection element of a block falling outside a radiation exposure field out of the blocks, is not used for the calculation.

5. The apparatus according to claim 1 , wherein a unit is constituted by arranging blocks which include the conversion element and a detection signal line in line along the detection signal line, and a plurality of units are arranged in a direction perpendicular to a column of the blocks.

6. A radiation imaging system comprising:
a radiation source that generates radiation; and
a radiation imaging apparatus according to claim 1 .

7. The system according to claim 6 , wherein said radiation source is controlled based on a control signal from an information processing unit.

8. The apparatus according to claim 1 , wherein the apparatus comprises a pixel array arranged a plurality of pixels in matrix, and the pixel array comprises a first pixel and a second pixel,
wherein the first pixel includes the detection element, the second pixel includes the conversion element and does not include the detection element, and the detection line is arranged along a column of the pixel array.

9. The apparatus according to claim 8 , the second pixel further including a switching element connected between a column signal line arranged along the column and the conversion element,
wherein the column signal line also operates as the detection signal line.

10. The apparatus according to claim 9 , the first pixel further including a switching element connected between the detection line and the detection element.

11. The apparatus according to claim 10 , the first pixel further including the conversion element and a switching element connected between the conversion element and the column signal line.

12. The apparatus according to claim 8 , the second pixel further including a switching element connected between the conversion element and a column signal line arranged along a column of the pixel array separately from the detection signal line,
wherein the detection signal line is arranged between a plurality of the column signal lines.

13. The apparatus according to claim 12 , the first pixel further including a switching element connected between the detection signal line and the detection element.

14. The apparatus according to claim 13 , the first pixel further including a switching element connected between the conversion element and the column signal line.

15. The apparatus according to claim 1 , the processing unit comprising
a first storage unit storing capacitance information of the conversion element, the detection element, and the parasitic capacitance,
a second storage unit storing signal information provided by the detection signal line, and
an arithmetic processing unit connected to the first storage unit and the second storage unit for performing the calculation.

Assignees

• Canon Kk

Inventors

• Kawanabe Jun
• Watanabe Minoru
• Yokoyama Keigo
• Ofuji Masato
• Fujiyoshi Kentaro
• Wayama Hiroshi

Classifications

• G01T1/023 Primary

  Scintillation dose-rate meters · CPC title

• H04N25/702

  SSIS architectures characterised by non-identical, non-equidistant or non-planar pixel layout · CPC title

• G01T1/247 Primary

  Detector read-out circuitry (for processing gain or off-set correction H04N) · CPC title

• G01T1/026

  Semiconductor dose-rate meters · CPC title

• H04N5/32

  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) · CPC title