Radiographic image capturing apparatus and control method thereof

Patent metadata

Field	Value
Publication number	US-9470802-B2
Application number	US-201514714600-A
Country	US
Kind code	B2
Filing date	May 18, 2015
Priority date	May 26, 2014
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

A radiographic image capturing apparatus, comprising a plurality of sensors arrayed on a substrate, a driving unit, a detection unit and a control unit, wherein the control unit is configured to perform a first control controlling the driving unit so as to repeatedly initialize the plurality of sensors on a row-by-row basis before a start of emission of radiation, and a second control controlling the driving unit so as to interrupt the initialization in response to a detection signal from the detection unit and cause the plurality of sensors to output signals, and the apparatus further comprises a determination unit configured to determine whether or not the detection signal is a signal which was output in response to the start of emission of radiation.

First claim

What is claimed is:

1. A radiographic image capturing apparatus comprising:
a plurality of sensors arranged so as to form a plurality of rows and a plurality of columns;
a driving unit configured to drive the plurality of sensors on a row-by-row basis;
a detection unit configured to output a detection signal in response to a start of emission of radiation; and
a control unit,
wherein the control unit is configured to perform:
a first control controlling the driving unit so as to repeatedly initialize the plurality of sensors on a row-by-row basis before the start of emission of radiation; and
a second control controlling the driving unit so as to interrupt the initialization in response to the detection signal and cause the plurality of sensors to output signals, and
the radiographic image capturing apparatus further comprises a determination unit configured to make a determination as to whether or not the detection signal is a signal that was output in response to the start of emission of radiation based on a difference between signals from sensors in a last initialized row in the first control and signals from sensors in a row other than the last initialized row from among the signals from the plurality of sensors output in the second control.

2. The radiographic image capturing apparatus according to claim 1 ,
wherein the determination unit is configured to make the determination based on a difference between an average value of the signals from the sensors in the last initialized row and an average value of the signals from the sensors in a row other than the last initialized row.

3. The radiographic image capturing apparatus according to claim 1 ,
wherein the control unit is configured to further perform, before or after the first control and the second control, a third control controlling the driving unit such that the plurality of sensors output signals corresponding to charges generated in the plurality of sensors while radiation is not emitted to the plurality of sensors, and
the radiographic image capturing apparatus further comprises an output unit configured to output differences between the signals from the plurality of sensors output in the second control and the signals from the plurality of sensors output in the third control as image data.

4. The radiographic image capturing apparatus according to claim 1 , further comprising a notification unit configured to notify a user of a result of the determination made by the determination unit.

5. The radiographic image capturing apparatus according to claim 4 , further comprising a radiation source configured to generate radiation, and a display unit,
wherein the notification unit is configured to output content of the notification to the display unit.

6. The radiographic image capturing apparatus according to claim 1 , further comprising a radiation source configured to generate radiation.

7. A radiographic image capturing apparatus comprising:
a plurality of sensors arranged so as to form a plurality of rows and a plurality of columns;
a driving unit configured to drive the plurality of sensors on a row-by-row basis; and
a detection unit configured to output a detection signal in response to a start of emission of radiation; and
a control unit,
wherein the control unit is configured to perform:
a first control controlling the driving unit so as to repeatedly initialize the plurality of sensors on a row-by-row basis before the start of emission of radiation;
a second control controlling the driving unit so as to interrupt the initialization in response to the detection signal and cause the plurality of sensors to output signals; and
a third control controlling the driving unit such that the plurality of sensors output signals corresponding to charges generated in the plurality of sensors while radiation is not emitted to the plurality of sensors, the third control being performed before or after the first control and the second control, and
the radiographic image capturing apparatus further comprises:
an output unit configured to output differences between the signals from the plurality of sensors output in the second control and the signals from the plurality of sensors output in the third control as image data; and
a determination unit configured to make a determination as to whether or not the detection signal is a signal that was output in response to the start of emission of radiation based on a difference between a first portion corresponding to a last initialized row in the first control and a second portion corresponding to a row other than the last initialized row in the image data output by the output unit.

8. The radiographic image capturing apparatus according to claim 7 ,
wherein the determination unit is configured to make the determination based on a difference between an average value in the first portion and an average value in the second portion.

9. A control method for controlling a radiographic image capturing apparatus,
the radiographic image capturing apparatus including a plurality of sensors arranged so as to form a plurality of rows and a plurality of columns, and a detection unit configured to output a detection signal in response to a start of emission of radiation,
the control method comprising:
a first step of repeatedly initializing the plurality of sensors on a row-by-row basis before a start of emission of radiation;
a second step of interrupting the initialization in response to the detection signal and driving the plurality of sensors such that the plurality of sensors output signals; and
a third step of making a determination as to whether or not the detection signal is a signal that was output in response to the start of emission of radiation based on a difference between signals from sensors in a last initialized row in the first step and signals from sensors in a row other than the last initialized row from among the signals from the plurality of sensors output in the second step.

10. The control method for controlling a radiographic image capturing apparatus according to claim 9 , further comprising a fourth step of notifying a user of a result of the determination made in the third step.

Assignees

• Canon Kk

Inventors

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

Classifications

• G01T1/208 Primary

  Circuits specially adapted for scintillation detectors, e.g. for the photo-multiplier section · CPC title

• H04N25/673

  by using reference sources · CPC title

• H04N5/361

  Electricity · mapped topic

• H04N25/618

  for random or high-frequency noise · CPC title

• H04N25/616

  involving a correlated sampling function, e.g. correlated double sampling [CDS] or triple sampling · CPC title