Radiation imaging apparatus and control method of the same

Patent metadata

Field	Value
Publication number	US-9980685-B2
Application number	US-201715643681-A
Country	US
Kind code	B2
Filing date	Jul 7, 2017
Priority date	Apr 9, 2014
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

A radiation imaging apparatus comprising a plurality of sensors arrayed to form a plurality of rows and a plurality of columns on a substrate and a driving unit configured to drive the plurality of sensors row by row, wherein the driving unit performs a first operation of driving the plurality of sensors while selecting the plurality of rows in a first order, and a second operation of driving the plurality of sensors while selecting the plurality of rows in a second order different from the first order after the first operation, such that a time difference is produced between a sensor in each row and a sensor in a neighboring row from the selection in the first order to the selection in the second order.

First claim

What is claimed is:

1. A radiation imaging apparatus comprising:
a plurality of sensors arrayed to form a plurality of rows and a plurality of columns;
a driving unit configured to drive the plurality of sensors row by row; and
a correcting unit, wherein
a first irradiation is performed to the plurality of sensors, and then a second irradiation is performed to the plurality of sensors,
the driving unit performs,
first driving to drive the plurality of sensors while selecting the plurality of rows in a first order, in accordance with the first irradiation, such that the plurality of sensors output signals corresponding to the first irradiation, and
second driving to drive the plurality of sensors while selecting the plurality of rows in a second order, in accordance with the second irradiation, such that the plurality of sensors output signals corresponding to the second irradiation, the second order being different from the first order,

among two neighboring rows of the plurality of rows, (i) a period from when the sensor in one row is driven in the first driving to when the sensor in the one row is driven in the second driving and (ii) a period from when the sensor in the other row is driven in the first driving to when the sensor in the other row is driven in the second driving are different from each other, and
the correcting unit corrects a signal from the sensor driven in the second driving in at least one of a first row and a second row neighboring each other, based on a signal from the sensor in the first row, a signal from the sensor in the second row and a difference of the period between the first row and the second row.

2. The apparatus according to claim 1 , further comprising a divider configured to divide the plurality of sensors into two or more groups row by row, wherein
the divider divides the plurality of sensors such that two neighboring rows belong to two different groups, respectively, and
the driving unit performs the first driving and the second driving group by group.

3. The apparatus according to claim 2 , wherein
the number of groups divided by the divider is two, and
the driving unit performs the first driving and the second driving by an interlace method.

4. The apparatus according to claim 1 , further comprising a divider configured to divide the plurality of sensors into two or more groups row by row, wherein
the divider divides the plurality of sensors such that two neighboring rows belong to two different groups, respectively, and
the driving unit performs one of the first driving and the second driving group by group.

5. The apparatus according to claim 1 , further comprising a calculating unit configured to calculate correcting information for correcting the signal from the sensor in the at least one of the first row and the second row, based on the signal from the sensor in the first row, the signal from the sensor in the second row and the difference of the period between the first row and the second row,
wherein the correcting unit corrects the signal from the sensor in the at least one of the first row and the second row, based on the correcting information calculated by the calculating unit.

6. The apparatus according to claim 5 , wherein the calculating unit calculates the correcting information, based on a difference between the signal from the sensor in the first row and the signal from the sensor in the second row, and the difference of the period between the first row and the second row.

7. The apparatus according to claim 5 , wherein
the plurality of sensors are divided into two or more regions, and
the calculating unit calculates the correcting information for each region.

8. The apparatus according to claim 7 , wherein the plurality of sensors are divided into two or more regions for at least every two rows, for at least every two columns, or for every unit region including at least two rows and at least two columns.

9. The apparatus according to claim 5 , further comprising a determination unit configured to determine whether the correcting information satisfies a predetermined condition,
wherein the correcting unit does not correct the signal from the sensor in the at least one of the first row and the second row, in a case where the determination unit does not determine the correcting information satisfies the predetermined condition.

10. The apparatus according to claim 5 , wherein
the driving unit drives the plurality of sensors, before/after both the first irradiation and the second irradiation, to output signals corresponding to charges generated in the plurality of sensors in a state of non-irradiation, and
the correcting unit performs
first correction to correct signals from the plurality of sensors driven in the second driving, using signals from the plurality of sensors in the state of non-irradiation, and
second correction to correct the signal from the sensor in the at least one of the first row and the second row, among the signals corrected in the first correction, using the signal from the sensor the first row, the signal from the sensor the second row, and the difference of the period between the first row and the second row.

11. The apparatus according to claim 1 , wherein the signal from each sensor driven in the second driving includes a noise component corresponding to the period from when the sensor is driven in the first driving to when the sensor is driven in the second driving.

12. The apparatus according to claim 1 , further comprising a measurement unit configured to measure the period for the sensor in each row.

13. The apparatus according to claim 1 , further comprising a radiation generation source configured to generate radiation.

14. A method for controlling a radiation imaging apparatus, the apparatus comprising a plurality of sensors arrayed to form a plurality of rows and a plurality of columns, and a driving unit configured to drive the plurality of sensors row by row, the method comprising:
first driving to drive the plurality of sensors while selecting the plurality of rows in a first order, in accordance with the first irradiation, such that the plurality of sensors output signals corresponding to the first irradiation;
second driving to drive the plurality of sensors while selecting the plurality of rows in a second order, in accordance with the second irradiation, such that the plurality of sensors output signals corresponding to the second irradiation, the second order being different from the first order; and
correcting a signal, wherein,
among two neighboring rows of the plurality of rows, (i) a period from when the sensor in one row is driven in the first driving to when the sensor in the one row is driven in the second driving and (ii) a period from when the sensor in the other row is driven in the first driving to when the sensor in the other row is driven in the second driving are different from each other, and
in the correcting, a signal from the sensor driven in the second driving in at least one of a first row and a second row neighboring each other is corrected, based on a signal from the sensor in the first row, a signal from the sensor in the second row and a difference of the period between the first row and the second row.

Assignees

• Canon Kk

Inventors

• Iwashita Atsushi
• Kameshima Toshio
• Yagi Tomoyuki
• Takenaka Katsuro
• Okada Hideyuki
• Sato Eriko
• Ryu Takuya
• Terui Kosuke

Classifications

• H04N25/63

  applied to dark current · CPC title

• A61B6/542

  involving control of exposure · CPC title

• A61B6/4233 Primary

  using matrix detectors · CPC title

• A61B6/5258

  involving detection or reduction of artifacts or noise · CPC title

• H04N5/361

  Electricity · mapped topic