Radiation imaging apparatus and control method of the same

Patent metadata

Field	Value
Publication number	US-9737271-B2
Application number	US-201514675852-A
Country	US
Kind code	B2
Filing date	Apr 1, 2015
Priority date	Apr 9, 2014
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

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 on a substrate;
a driving unit configured to drive the plurality of sensors row by row, said driving unit performing:
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 a timing of the selection in the first order to a timing of the selection in the second order; and
a correcting unit configured to correct a signal, based on a signal from each sensor in a first row as one of the plurality of rows, a signal from each sensor in a second row neighboring the first row, and the time difference between the first row and the second row, the signal to be corrected being from a sensor in at least one of the first row and the second row among the plurality of sensors which are driven in the second order in the second operation.

2. The apparatus according to claim 1 , wherein
said driving unit
performs the first operation before emission of radiation, and repetitively initializes the plurality of sensors in the first operation,
performs the second operation in response to emission of radiation, and drives the plurality of sensors to read out signals from the plurality of sensors in the second operation, and
performs the first operation and the second operation such that a time difference is produced between neighboring rows from a timing at which each sensor is initialized last in the first operation to a timing at which a signal is read out in the second operation.

3. The apparatus according to claim 1 , further comprising a calculating unit configured to calculate correction information for the correction by said correcting unit, based on a signal from a sensor in the first row, a signal from a sensor in the second row, and the time difference between the first row and the second row.

4. The apparatus according to claim 3 , wherein said calculating unit calculates the correction information based on a signal value difference between a signal from a sensor in the first row and a signal from a sensor in the second row, and the time difference between the first row and the second row.

5. The apparatus according to claim 3 , wherein
the plurality of sensors are divided into two or more regions, and
said calculating unit calculates the correction information for each region.

6. The apparatus according to claim 5 , 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.

7. The apparatus according to claim 3 , further comprising a determination unit configured to determine whether the correction information satisfies a predetermined condition,
wherein said correcting unit does not perform the correction if said determination unit determines that the correction information does not satisfy the predetermined condition.

8. The apparatus according to claim 1 , further comprising a dividing unit configured to divide the plurality of sensors into two or more groups for every row, such that two neighboring rows belong to different groups,
wherein said driving unit performs both the selection of the plurality of rows in the first order in the first operation and the selection of the plurality of rows in the second order in the second operation, by dividing the plurality of sensors into two or more groups for every row by said dividing unit.

9. The apparatus according to claim 8 , wherein
the number of groups divided by said dividing unit is two, and
said driving unit performs the selection in the first order and the selection in the second order by an interlace method.

10. The apparatus according to claim 1 , further comprising a dividing unit configured to divide the plurality of sensors into two or more groups for every row, such that two neighboring rows belong to different groups,
wherein said driving unit performs one of the selection of the plurality of rows in the first order in the first operation and the selection of the plurality of rows in the second order in the second operation, by dividing the plurality of sensors into two or more groups for every row by said dividing unit.

11. The apparatus according to claim 10 , wherein
the number of groups divided by said dividing unit is two, and
said driving unit performs the selection in the first order by one of an interlace method and a progressive method, and performs the selection in the second order by the other method.

12. The apparatus according to claim 1 , wherein a signal from each sensor contains a noise component whose amount corresponds to a time from a timing at which the sensor is driven last in the first operation to a timing at which the sensor is driven in the second operation.

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

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

15. A control method of a radiation imaging apparatus comprising a plurality of sensors arrayed to form a plurality of rows and a plurality of columns on a substrate, comprising:
a first step of driving the plurality of sensors while selecting the plurality of rows in a first order;
a second step of driving the plurality of sensors while selecting the plurality of rows in a second order different from the first order after the first step, such that a time difference is produced, between a sensor in each row and a sensor in a neighboring row, from a timing of the selection in the first order to a timing of the selection in the second order; and
correcting a signal, based on a signal from each sensor in a first row as one of the plurality of rows, a signal from each sensor in a second row neighboring the first row, and the time difference between the first row and the second row, the signal to be corrected being from a sensor in at least one of the first row and the second row among the plurality of sensors which are driven in the second order in the second operation.

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

• A61B6/4233 Primary

  using matrix detectors · CPC title

• A61B6/4208 Primary

  characterised by using a particular type of detector · CPC title

• A61B6/542

  involving control of exposure · CPC title

• H04N5/361

  Electricity · mapped topic